JP5838864B2 - Thermocouple mounting method and coated thermocouple - Google Patents

Description

  The present invention relates to a thermocouple mounting method and a coated thermocouple.

  The thermocouple is a temperature sensor that uses two electromotive forces due to a temperature difference between two joints by joining two ends of two strands made of different metals to form two joints. The measurable temperature range varies depending on the characteristics of the wire to be joined, and it is widely used for temperature measurement in various environments from low temperature to high temperature. In particular, a thermocouple for a high temperature region is known to be provided with a protective film since metal is oxidized and deteriorated when used for a long time (see Patent Document 1).

  Patent Document 1 describes a method for manufacturing a coated thermocouple in which a metal oxide film for coating is formed on the surfaces of two strands. According to the manufacturing method of Patent Document 1, since two strands are covered with a metal oxide film that is stable even at high temperatures, deterioration due to oxidation is reduced, and the coated thermocouple has a long service life. ing.

JP-A-6-229837

  When in use, the thermocouple measures the temperature of the measurement object by bringing the joint of the ends of the two strands into contact with the measurement object. However, in the coated thermocouple described in Patent Document 1, not only the strands but also the joints are covered with a metal oxide film. For this reason, when used, a metal oxide film is interposed between the joint and the object to be measured, and heat conduction is hindered, and the responsiveness of the coated thermocouple is reduced.

  This invention is made | formed in view of the said subject, The objective is to provide the thermocouple attachment method and coating | coated thermocouple which can improve a service life, without impairing responsiveness.

  The thermocouple attachment method of the present invention is a thermocouple attachment method for attaching a thermocouple to an adherend, and is prepared to prepare a thermocouple having two strands in which each end is joined to each other to form a joint. A fixing step for fixing the bonding portion to the adherend, and a covering step that is performed after the fixing step and covers a part of the adherend and the two strands with a metal oxide film. Include.

  In one embodiment, the thermocouple attachment method of the present invention further includes an attachment step of attaching the adherend to a measurement object, and in the attachment step, another part different from the part of the adherend. Is attached to the measurement object.

  In one embodiment, the adherend is a reinforcing member that reinforces contact between the joint and the measurement object.

  In one embodiment, the reinforcing member has a plate shape.

  In one embodiment, the reinforcing member includes at least one of platinum, rhodium, iridium, and palladium.

  In one embodiment, the adherend is a measurement object.

  In one embodiment, the metal oxide film includes at least one of zirconia, yttria, alumina, titania, magnesia, and silica.

  In one embodiment, in the coating step, the metal oxide film is coated by at least one of spraying, coating, vapor deposition, sputtering, and chemical vapor deposition.

  The coated thermocouple of the present invention is a coated thermocouple for measuring the temperature of an object to be measured, the thermocouple having two strands in which each end is joined to each other to form a joined portion, and the joined portion. An adherend that is in direct contact with the substrate, and a metal oxide film that covers a portion of the adherend and a portion of the thermocouple excluding a portion that is in contact with the adherend. The reinforcing member reinforces the contact between the joint of the two strands and the measurement object.

  In one embodiment, the reinforcing member has a plate shape.

  In one embodiment, the reinforcing member includes at least one of platinum, rhodium, iridium, and palladium.

  In one embodiment, the metal oxide film includes at least one of zirconia, yttria, alumina, titania, magnesia, and silica.

  According to the thermocouple attachment method of the present invention, it is possible to provide a coated thermocouple having an improved service life without impairing responsiveness.

It is a mimetic diagram showing a covering thermocouple concerning an embodiment of the present invention. (A)-(c) is a figure for demonstrating the attachment method of the covering thermocouple which concerns on embodiment of this invention. It is a mimetic diagram showing a covering thermocouple concerning an embodiment of the present invention. (A)-(d) is a figure for demonstrating the attachment method of the covering thermocouple which concerns on embodiment of this invention.

  Embodiments of a thermocouple mounting method and a coated thermocouple according to the present invention will be described below with reference to the drawings. However, the present invention is not limited to the following embodiments.

  FIG. 1 is a schematic diagram showing a coated thermocouple 10A according to an embodiment of the present invention. The coated thermocouple 10A attached to the measurement object 20 will be described with reference to FIG. The coated thermocouple 10 </ b> A includes a thermocouple 1 and a metal oxide film 13. The measurement object 20 is exemplified by a pipe made of platinum for the sake of explanation, but may be another material or structure.

  The thermocouple 1 has two strands 11. One end of each of the two strands 11 is joined to each other to form a temperature measuring joint 111, and the other end is connected to a temperature measuring device (not shown). The joining part 111 is arrange | positioned so that the to-be-adhered body 12 may be contacted. In the present embodiment, the adherend 12 is the measurement object 20. Thus, the temperature of the platinum pipe as the measuring object 20 (the adherend 12) can be measured by the temperature measuring device. The two strands 11 are divided into a plus leg and a minus leg, and the components are different from each other, and the type can be appropriately selected depending on the temperature range to be measured, the measurement accuracy, and the like. The present invention does not limit the types of the two wires 11 and may be those defined in B, R, S, K, E, J, T, and N of JIS C1602 (1995). It may be outside. For example, the strand 11 containing platinum is used for temperature measurement in a high temperature region.

  Part of the adherend 12 and the two strands 11 excluding the contact portion 112 where the bonding portion 111 contacts the adherend 12 are covered with the metal oxide film 13. In the present embodiment, the two strands 11 are covered with the metal oxide film 13 except for the contact portion 112 where the bonding portion 111 is in contact with the measurement object 20. As the metal oxide film 13, a film having excellent stability at high temperature is used. However, the metal oxide film 13 has toughness and does not break easily, and has a thermal expansion coefficient close to that of the element wire 11, so From the viewpoint of being difficult to peel off from the wire 11, those containing at least one of zirconia, yttria, alumina, titania, magnesia and silica are particularly preferable.

  As described with reference to FIG. 1, in the coated thermocouple 10 </ b> A of the present embodiment, the two strands 11 of the thermocouple 1 are in contact with each other at which the joint portion 111 contacts the measurement object 20 (the adherend 12). The metal oxide film 13 is covered except for the portion 112. For this reason, deterioration of the strand 11 by oxidation is prevented. Furthermore, since a part of the bonding part 111 is in direct contact with the measurement object 20 (the adherend 12) without passing through the metal oxide film 13, heat is not blocked by the metal oxide film 13. It is possible to conduct between 111 and the measurement object 20 (the adherend 12). With such a configuration, the service life of the coated thermocouple 10A can be improved without impairing responsiveness.

  FIGS. 2A to 2C are views for explaining a method of attaching the coated thermocouple 10A according to the embodiment of the present invention. Hereinafter, with reference to FIG. 2, a thermocouple attachment method for suitably attaching the coated thermocouple 10A will be described. The thermocouple attachment method of this embodiment is performed by the following steps.

  (1) As shown in FIG. 2A, a thermocouple 1 having two strands 11 each having one end joined to each other to form a joint 111 is prepared. As described above, the material of the wire 11 can be appropriately selected as necessary.

  (2) As shown in FIG. 2 (b), the joining portion 111 is fixed to the adherend 12. In this embodiment, the adherend 12 is a measurement object 20 that is a target for temperature measurement. Specifically, the measuring object 20 is a pipe made of platinum, for example, and the joint 111 of the two strands 11 is fixed on the surface thereof. The joint 111 is fixed by, for example, welding, but the present invention is not limited to this. The joint portion 111 may be fixed to the measurement object 20 (the adherend 12) by means other than welding (for example, adhesion or mechanical fixation).

  (3) As shown in FIG. 2C, after the fixing step, a part of the measurement object 20 (the adherend 12) and the thermocouple 1 are covered with the metal oxide film 13. The coating means can be, for example, thermal spraying. Specifically, on the surface of the two strands 11 including the joint 111 except for the contact portion 112 where the joint 111 contacts the platinum pipe as the measurement object 20 (the adherend 12), a metal Cover with oxide film 13.

  As the metal oxide film 13, as described above, a film containing at least one of zirconia, yttria, alumina, titania, magnesia, and silica is used. Here, a part of the measurement object 20 (the adherend 12) and the thermocouple 1 are covered with the metal oxide film 13 by thermal spraying, but the present invention is not limited to this. The coating of the metal oxide film 13 is performed, for example, by at least one of spraying, coating, vapor deposition, sputtering, and chemical vapor deposition (CVD).

  As described with reference to FIG. 2, the coating of the metal oxide film 13 was performed after fixing the bonding portion 111 to the measurement target 20 (the adherend 12), and therefore a part of the bonding portion 111 was subjected to metal oxidation. It is in direct contact with the measuring object 20 without passing through the physical film 13. Thus, according to the thermocouple attachment method of the present embodiment, the above-described coated thermocouple 10A can be suitably attached.

  In the coated thermocouple 10A of the above-described embodiment, the joint portion 111 of the two strands 11 is in direct contact with the measurement object 20 without any other member, but the present invention is not limited to this. The joint part 111 of the two strands 11 may contact the measuring object 20 through another member.

  FIG. 3 is a schematic diagram showing a coated thermocouple 10B according to an embodiment of the present invention. Hereinafter, with reference to FIG. 3, the coated thermocouple 10 </ b> B of the present embodiment will be described. The coated thermocouple 10 </ b> B includes two strands 11, an adherend 12, and a metal oxide film 13.

  The coated thermocouple 10B of the present embodiment has the same configuration as the coated thermocouple 10A described above with reference to FIG. 1 except that an adherend 12 different from the measurement target 20 is further provided. Therefore, a duplicate description is omitted. In the coated thermocouple 10 </ b> B, the adherend 12 is a reinforcing member 121 that reinforces the contact between the joint portion 111 of the two strands 11 and the measurement object 20, and the joint portion 111 is measured via the reinforcing member 121. It is in contact with the object 20. The reinforcing member 121 has a plate shape, part of which is in direct contact with the joint 111 and fixed to the joint 111, and the other part is in contact with a platinum pipe as the measurement object 20. Mounted on the measurement object 20.

  Part of the adherend 12 and the two strands 11 excluding the contact portion 112 where the bonding portion 111 contacts the adherend 12 are covered with the metal oxide film 13. In the present embodiment, the reinforcing member 121 and the two strands 11 as the adherend 12 include a contact portion 122 where the reinforcing member 121 contacts the measuring object 20 and a contact portion 112 where the joint 111 contacts the reinforcing member 121. Are covered with the metal oxide film 13.

  In the present embodiment, the reinforcing member 121 has a plate shape, and can contact the measurement object 20 in a relatively large area. For this reason, compared with the case where the joining part 111 is made to contact the measuring object 20 directly, the joining part 111 resulting from a thermal deformation etc. is brought into contact with the joining part 111 and the measuring object 20 via the reinforcing member 121. Can be suitably prevented. Here, although the reinforcing member 121 has a plate shape, the present invention is not limited to this. The reinforcing member 121 may have a shape (for example, a rod shape) other than the plate shape as long as the connection between the joint portion 111 and the measurement object 20 can be reinforced.

  For example, platinum is used as the reinforcing member 121. However, the present invention is not limited to this. The reinforcing member 121 can be appropriately selected depending on the material of the wire 11 or the measurement object 20 and the environment in which the temperature is measured. Preferably, the reinforcing member 121 is made of a material that is similar or identical to the measurement object 20 so that good welding can be obtained when the reinforcement member 121 is welded to the wire 11 or the measurement object 20. Preferably, the reinforcing member 121 is a material having high chemical stability in order to prevent deterioration due to oxidation. For example, the reinforcing member 121 may include at least one of platinum group metals such as platinum, rhodium, iridium, and palladium.

  As described with reference to FIG. 3, in the coated thermocouple 10 </ b> B of the present embodiment, the two strands 11 are formed of a metal oxide film except for the contact portion 112 where the bonding portion 111 contacts the adherend 12. 13 is covered. For this reason, at the time of temperature measurement, deterioration of the strand 11 by oxidation is prevented. Further, a part of the bonding portion 111 is in direct contact with the adherend 12 without the metal oxide film 13, and a part of the adherend 12 is directly with the measurement object 20 without the metal oxide film 13. Since they are in contact with each other, heat can be conducted between the joint 111 and the measurement object 20 without being blocked by the metal oxide film 13. With such a configuration, the service life of the coated thermocouple 10B can be improved without impairing responsiveness.

  4A to 4D are views for explaining a method of attaching the coated thermocouple 10B according to the embodiment of the present invention. Hereinafter, with reference to FIG. 4, a thermocouple attachment method for suitably attaching the coated thermocouple 10B will be described. The thermocouple attachment method of this embodiment is performed by the following steps.

  (1) As shown in FIG. 4A, a thermocouple 1 having two strands 11 is prepared. The two strands 11 include a joint portion 111 with their one ends joined together. As described above, the type of the wire 11 can be appropriately selected as necessary.

  (2) As shown in FIG. 4B, the joining portion 111 is fixed to the adherend 12. In the present embodiment, the adherend 12 is a reinforcing member 121 that reinforces the contact between the joint portion 111 of the two strands 11 and the measurement target 20. Specifically, the adherend 12 is made of, for example, platinum and has a plate shape, and the joining portion 111 is fixed to a part thereof.

  The fixing means between the reinforcing member 121 and the joint 111 is not particularly limited, and may be, for example, caulking, welding, or adhesion. In the case of fixing by caulking, the joint portion 111 is sandwiched between the reinforcing member 121 and a crimping member (not shown). The joining portion 111 is crimped to the reinforcing member 121 by a crimping member. In addition, in FIG.4 (b), although the junction part 111 was being fixed to the peripheral part vicinity of the reinforcement member 121, this invention is not limited to this. The joining portion 111 may be fixed near the center of the main surface of the reinforcing member 121.

  (3) As shown in FIG. 4C, after the fixing step, a part of the adherend 12 and the thermocouple 1 are covered with a metal oxide film 13. The coating means can be, for example, thermal spraying. Specifically, the surface of the two strands 11 including the bonding portion 111 and a part of the surface of the reinforcing member 121 except for the contact portion 112 where the bonding portion 111 contacts the reinforcing member 121 as the adherend 12. Are covered with a metal oxide film 13. Another part of the surface of the reinforcing member 121 that is not covered with the metal oxide film 13 is used for mounting in a mounting process to be described later. Therefore, the width of the region is adjusted as necessary when mounting.

  As for the type of the metal oxide film 13, a film containing at least one of zirconia, yttria, alumina, titania, magnesia, and silica is used as in the embodiment described above with reference to FIG. 1. Here, the coating of the metal oxide film 13 is performed by thermal spraying. However, in addition to thermal spraying, it can be performed by at least one of film forming means such as coating, vapor deposition, sputtering, and CVD.

  (4) As shown in FIG. 4 (d), the reinforcing member 121 as the adherend 12 is attached to the measurement object 20. Specifically, in the covering step, another part different from the part covered with the metal oxide film 13 of the reinforcing member 121 is attached to the measurement object 20 by the attachment member 30. Here, welding is used as the attachment means, and the adherend 12 is attached to the measurement object 20 by the attachment member 30 which is a welding material. However, the present invention is not limited to this. Examples of attachment means for the adherend 12 include adhesion, mechanical fixation, and the like in addition to welding. The adherend 12 can be attached to the measurement object 20 in a non-detachable or detachable manner as required. For example, when a detachable fixing tool is used as the mounting member 30, the adherend 12 is detachable. However, from the viewpoint of preventing deterioration of the entire adherend 12 due to oxidation, the adherend 12 can seal other part different from the part covered with the metal oxide film 13 (for example, welding described above). Is preferably attached to the measuring object 20.

  As described with reference to FIG. 4, since the metal oxide film 13 is coated after the reinforcing member 121 as the adherend 12 is fixed to the joint portion 111, a part of the joint portion 111 is a metal oxide. The reinforcing member 121 is in direct contact with no membrane 13 interposed. In addition, since the metal oxide film 13 is not coated on the contact portion 122 where the reinforcing member 121 contacts the measuring object 20, a part of the reinforcing member 121 does not pass through the metal oxide film 13. In direct contact. Thus, according to the thermocouple attachment method of the present embodiment, the above-described coated thermocouple 10B can be suitably attached.

  The present invention can use a thermocouple for measuring the temperature of an object to be measured.

DESCRIPTION OF SYMBOLS 1 Thermocouple 10A, 10B Coated thermocouple 11 Wire 111 Joint part 112 Contact part 12 Adhered object 121 Reinforcement member 122 Contact part 13 Metal oxide film 20 Measuring object 30 Mounting member

Claims (6)

A thermocouple attachment method for attaching a thermocouple to an adherend,
A preparation step of preparing a thermocouple having two strands in which each end is joined to each other to form a joint;
A fixing step of fixing the joining portion to the adherend;
A coating step that is performed after the fixing step and covers a part of the adherend and the two strands with a metal oxide film ;
A mounting step of mounting the adherend to a measurement object;
Including
A thermocouple mounting method in which, in the mounting step, another part different from the part of the adherend is mounted on the measurement object . The thermocouple attachment method according to claim 1 , wherein the adherend is a reinforcing member that reinforces contact between the joint and the measurement object. The thermocouple attachment method according to claim 2 , wherein the reinforcing member has a plate shape. The thermocouple attachment method according to claim 2 or 3 , wherein the reinforcing member includes at least one of platinum, rhodium, iridium, and palladium. At least one containing, thermocouple mounting method according to any one of claims 1 to 4 of the metal oxide film is zirconia, yttria, alumina, titania, magnesia and silica. In the coating step, the coating of metal oxide film, thermal spraying, coating, vapor deposition is carried out by at least one of sputtering and chemical vapor deposition, thermoelectric according to any one of claims 1 5 Pair mounting method.

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