JPH0716129U - Resistance temperature detector element - Google Patents

Abstract

(57) [Summary] [Purpose] An object is to provide a resistance temperature detector element that can be used for a long time in a high temperature and radiation environment. [Arrangement] A resistance temperature detector element comprising a platinum core wound around a cylindrical core formed of an inorganic insulating material, the platinum core being wound around a core formed of high-purity alumina. A temperature measuring resistor in which a groove is spirally engraved along the circumference of the surface of a cylinder, and the surface of a cylinder formed by winding a platinum wire along the groove is coated with high-purity alumina by thermal spraying. It is a body element.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a resistance temperature detector element that has excellent vibration resistance and maintains reliability even in a high temperature and radiation environment.

[0002]

[Prior art]

 The resistance thermometer element is required to have vibration resistance, withstand use at high temperature, good response, and withstand radiation environment. By the way, a conventional resistance thermometer resistance element has a method in which a resistance wire such as a platinum wire is wound around a winding core or a winding frame, and then an organic or inorganic adhesive is applied to fix the resistance wire. ing. When the core or reel is made of an inorganic insulating material, the resistance wire is wound around the surface of the core or reel, but when the core or reel is made of metal, a glass-based enamel (hollow) or Another method is to wind the resistance wire after insulating it with heat-resistant cement or heat-resistant tape.

An adhesive containing an organic resin as a main component cannot be used for a long time in a region where there is a risk of decomposition due to high temperature. Inorganic adhesives have a problem of hygroscopicity of the formed coating, and adhesive cement containing silica, boric acid, phosphoric acid, etc. requires moisture when mixing, and also resistance wire such as platinum wire coated on these materials. A chemical reaction occurs at high temperature, and resistance wire deterioration is observed.

In order to improve the responsiveness, an extremely thin resistance wire such as platinum is used in order to make the heat capacity as small as possible and the resistance value as large as possible. Therefore, the surface condition and strain of the resistance wire are used. In the state where is added, the temperature coefficient as a resistance temperature detector changes. In particular, platinum wire is soft, so rough bones on the surface are greatly affected.

[0005]

[Problems to be solved by the device]

 As described above, the material of the coating that fixes and insulates the wound resistance wire on the core of the conventional resistance thermometer element decomposes or deteriorates when used under high temperature or radiation environment, or chemically. The surface of the resistance wire is eroded due to the occurrence of the reaction. Therefore, if a resistance temperature detector element can be made of only high-purity alumina material, it will be an extremely effective means of solving the problem. Plasma spraying is most suitable for the surface alumina coating of this alumina reel, but if the resistance wire is wound on a core with a smooth surface as in the past, the platinum resistance wire may be damaged. It may cause a disconnection.

Further, since the resistance wire is strongly pulled and wound during the work of winding the winding wire around the winding core, there is a defect that distortion is left inside the resistance wire. In the present invention, except for the above-mentioned drawbacks, the resistance wire is firmly fixed on the winding core so as to withstand long-term use under high temperature and radiation environment, and is chemically stable even at high temperature. An object is to provide a resistance temperature detector element characterized by being coated.

[0007]

[Means for Solving the Problems]

 Therefore, in view of the above circumstances, the present invention uses, as a core material, high-purity alumina that is chemically stable even under a high temperature and radiation environment, and forms a groove along the outer periphery of the surface of the core. It is engraved in a spiral shape. The groove is a V-shaped groove having a deep valley portion having a diameter of 2 to 5 times the resistance wire diameter to be wound.

After winding and tightening the resistance wire along the groove, a high-purity aluminum is plasma-sprayed on the resistance wire to cover the resistance wire, and the resistance wire is fixed and formed on the winding core. Obtain the temperature sensor antibody element.

[0009]

[Action]

 When a thin resistance wire is wound around a smooth surface of a winding core as in the prior art, the Pt resistance wire may be damaged, broken, or the pitch may be disturbed to cause a short circuit. According to the present invention, when the winding groove is engraved with a groove deeper than the wire diameter, the winding does not loosen even if it is wound gently. It also eliminates scratches and breaks in the resistance wire.

When applying the thermal spray coating after winding the resistance wire around the winding core, the groove acts as a wedge effect to form a strong coating.

[0011]

【Example】

 The present invention will be described in detail with reference to specific embodiments shown in the accompanying drawings. FIG. 1 is a vertical sectional view of a resistance temperature detector element, and FIG. 2 is an enlarged sectional view of a main part of the present invention. A groove 2 is spirally formed along the outer surface of a winding core 1 made of high-purity alumina in a cylindrical shape, and a platinum resistance wire 3 is wound along the groove 2 to form a platinum resistance wire. The end 4 of 3 is connected to the end of the lead wire 5 by spot welding to electrically form a circuit. Here, the depth of the groove 2 is a V-shaped groove in a deep valley portion having a resistance wire diameter of 2 to 5 times.

After the platinum resistance wire 3 is wound around the winding core 1, the coating 6 of high-purity alumina is filled by plasma spraying in the groove 2 and the coating 6 is formed so that the platinum resistance wire 3 is embedded. Then, the surface 7 of the coating 6 is polished with a grinder of fine abrasive grains to make the surface 7 smooth if necessary. The plasma sprayed partial region is the part where the platinum resistance wire 3 is wound around the winding frame 1 and the part shown by the broken lines above and below it in FIG.

Reference numeral 8 is a hollow hole of the winding core 1. Use the resistance thermometer molded as described above in a stainless steel protective cylinder.

[0014]

[Effect of device]

 As described above, according to the features of the present invention, it is possible to prevent the platinum resistance wire from being scratched during plasma spraying by winding the resistance wire along the deep groove on the surface of the winding core. In addition, there is no possibility of disconnection during plasma spraying or contact of the platinum resistance wire due to disordered pitch and short-circuiting, making it easy to wind even an extremely thin platinum wire with a diameter of 0.025 mm. It is possible to make a resistance thermometer element with high resistance, small size and high resistance.

Furthermore, the groove firmly adheres the thermal spray coating and does not peel off. In addition, it withstands long-term use in high temperature and radiation environments and exhibits stable performance.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a resistance temperature detector element of the present invention.

FIG. 2 is an enlarged cross-sectional view of a main part of the present invention.

[Explanation of symbols]

 1 ... Core 2 ... Groove 3 ... Platinum resistance wire 4 ... End 5 ... Lead wire 6 ... Coating 7 ... Surface 8 ... Hollow hole

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor, Akira Nashimoto 1-1-1, Wadazaki-cho, Hyogo-ku, Kobe, Hyogo Prefecture Mitsubishi Heavy Industries, Ltd. Kobe Shipyard (72) Inventor, Mitsuaki Mochizuki 5-chome, Kizaki, Akashi-shi, Hyogo Prefecture No. 6-28 Stock company Okazaki factory Akashi factory (72) Inventor Masaru Yamana 5-6-28 Kizaki, Akashi city Hyogo prefecture Stock company Okazaki factory Akashi factory

Claims (1)

[Scope of utility model registration request] 1. A resistance thermometer element formed by winding a platinum wire around a cylindrical core formed of an inorganic insulating material, the spiral core being formed on the outer peripheral surface of the core formed of high-purity alumina. A groove is engraved, a platinum wire is wound along the groove, and a surface of a cylinder formed by winding the platinum wire along the groove is coated with high-purity alumina by thermal spraying. Resistance temperature detector element.