JP2014074651A - Consumption type thermocouple - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a consumption type thermocouple having high integrity between a paper tube and a coating tube and allowed to be simply and easily manufactured.SOLUTION: The consumption type thermocouple comprises a paper tube 1, a ceramic film 2, a chip 3, a protection tube 4, a pair of terminals 5, a thermocouple wire 6, and a heat resistant coating body 7 produced by casting. Since the heat resistant coating body 7 integrally coats an outer peripheral surface of the paper tube 1, the chip 3 fixed on a lower end of the outer peripheral surface and an upper side portion of the protection tube 4 projected from the chip 3 and the heat resistant coating body 7 has high integrity as a whole because of integral casting, damage of the heat resistant coating body 7 is reduced and high durability is achieved.

Description

  The present invention relates to a consumable thermocouple used for measuring the temperature of molten metal or the like.

  Conventionally, as shown in FIG. 3, a consumable thermocouple includes a paper bowl 101, a chip 102 provided at one end of the paper board 101, a protective basket 103 projecting from one end of the chip 102, and the chip 102. One end of a pair of terminals 104 provided on the other end of each of the terminals 104, one end of the terminals 104, and the other end of the terminals 104 are electrically connected, and the thermocouple held in the protective rod 103 One end side shaft hole of the heat-resistant covering rod 106 on one end side of the chip 102 with the wire 105, the heat-resistant covering rod 106 protruding to one end side of the paper sheet 101 and covering the outer peripheral surface of the one end side, and the tip end portion of the protective covering 103 And a heat-resistant stopper 107 that fills the surface. The heat-resistant covering rod 106 is formed by winding a ceramic fiber sheet containing an inorganic adhesive liquid around the outer peripheral surface of the paper rod 106 to have a predetermined thickness, and then heating to integrate. The heat-resistant plug portion 107 is formed by filling ceramic short fibers (Patent Document 1).

  A thermocouple plug (not shown) is inserted into the consumable thermocouple from the opening end on the other end side of the paper sheet 101. The electrode terminal contact provided at one end of the thermocouple plug contacts the terminal 104 of the chip 102. In this state, when a portion including the protective rod 103 on one end side of the consumable thermocouple is brought into contact with a molten metal or the like, an electromotive force is generated in the thermocouple wire 105, and the temperature of the molten metal is measured.

  Conventionally, a heat-resistant sheath or a heat-resistant sheath and a heat-resistant plug portion are separately covered with a heat-resistant material such as ceramic, and a cylindrical or bottomed tubular sheath is formed on one end of a paper tray having chips. Consumable thermocouples are also known.

JP 10-197358

  It is complicated to manufacture a heat-resistant coated tub by wrapping a ceramic sheet on one end side of a consumable thermocouple paper tub and filling a ceramic short fiber to form a heat-resistant plug. In addition, the heat-resistant covering rod and the heat-resistant stopper are divided into two parts, so that the integrity is lacking. A consumable thermocouple that covers a separately formed covering rod lacks the integrity of the paper rod and the covering rod.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a consumable thermocouple that has a high unity between a paper basket and a cover and is simple and easy to manufacture.

  In order to solve this problem, the present inventor has conceived of forming a heat-resistant coating rod and a heat-resistant plug portion on one end side of a paper bag by a casting method using a mold, and has completed the present invention. That is, the consumable thermocouple of the present invention is provided with a paper bag, a chip provided at one end of the paper bag, a protective bag protruding from one end side of the chip, and a second side of the chip. A pair of terminals, one end of the terminal, one end of the terminal being electrically connected to the other end and the other end of the terminal being electrically connected to the protective rod, and the tip of the protective rod protruding from the tip A heat-resistant covering that covers one end side of the paper sheet and an outer peripheral surface of the one end side of the paperboard, wherein the heat-resistant coating body is formed on the outer peripheral surface of the one end side of the paperboard and one end side of the chip It is the type | mold molded object cast | casted so that the end surface of this may be covered.

  The consumable thermocouple of the present invention is cast so that the heat-resistant coating covers the outer peripheral surface at one end of the paper basket. For this reason, the integrity of the heat-resistant covering and the paper sheet is high. Furthermore, since the covering rod and the heat-resistant plug portion are formed at a time, manufacturing is simple and easy.

  The paper bottles, chips, protective bottles, thermocouple wires, and the like that constitute the consumable thermocouple of the present invention can be the same as the conventional ones but have at least the same functions. A characteristic of the present invention is a heat-resistant coating. This heat-resistant covering covers the outer peripheral surface on one end side of the paper basket and the end surface on one end side of the chip, and shields high heat such as molten metal. Thereby, the one end side outer peripheral surface and chip | tip of a paper basket are protected from high heat. This heat-resistant covering is obtained by integrating a conventional heat-resistant covering rod and a heat-resistant stopper. Further, this heat-resistant covering is a molded body formed by casting so as to cover the outer peripheral surface on one end side of the paper basket and the one end surface of the chip. A castable used for producing a refractory material can be adopted as the casting material. As the castable, heat-resistant particles such as silica, alumina, and magnesia and heat-resistant fibers formed into a sol with a liquid adhesive can be used. About the kind and shape of a heat-resistant particle | grain and a heat-resistant fiber, it can select according to the object by which temperature is measured.

  A mold can be used for casting the heat-resistant coating. The mold defines the outer peripheral surface of the heat-resistant covering to be formed. It should be noted that the tip end portion of the protective rod for storing and holding the thermocouple wire inside needs to protrude outward from the heat-resistant covering. In addition, the root part of the buried protective cover must be covered with a heat-resistant covering without any gaps. One end side of the heat-resistant covering body from which the tip of the protective basket protrudes may be a plane orthogonal to the direction in which the paper basket extends, a truncated cone shape having an outer peripheral angle of the plane, or a hemispherical shape.

  In addition, it is preferable to wind a heat-resistant ceramic film around the outer peripheral surface of the paper sheet. This ceramic film suppresses burning of the outer peripheral surface of the paperboard by heat encountered during temperature measurement. A further function of the ceramic film is a function of suppressing the liquid such as water contained in the castable from being absorbed by the paper bottle when the heat-resistant coating is cast. The liquid such as water absorbed in the paper bottle takes a long time to dry because the paper bottle is thick. Absorption of water, etc. into the paper bag occurs on all surfaces where the castable comes into contact. It is preferable to cover the end face in which the paper chip chip is incorporated and the inner peripheral surface in the vicinity thereof with a ceramic film to avoid contact with the castable.

  In place of the ceramic film, it is also preferable that the surface of the paper basket is previously impervious to water and the like. In order to make it impervious, for example, a silicon resin film may be formed.

  If the paper sheet is impervious, it becomes easy to dry the paper sheet on which the heat-resistant coating is formed.

  A heat-resistant heat insulating material can be provided between the heat-resistant covering and the end face on one end side of the chip. Ceramic fiber can be used as the heat insulating material.

  In the present invention, the heat-resistant covering covering the outer peripheral surface of one end of the paper basket and the one end side of the chip is cast and formed so as to cover the outer peripheral surface and one end surface of the chip. For this reason, the integrity of the heat-resistant covering and the paper sheet is high, the configuration is simple, and the manufacture is easy. By providing a ceramic film on the surface of the paperboard in advance or making the surface of the paperpaper impervious, moisture absorption to the paperboard accompanying casting can be suppressed.

1 is a longitudinal sectional view of a consumable thermocouple of Embodiment 1. FIG. FIG. 3 is a longitudinal sectional view at the time of mold forming of Embodiment 1. It is a longitudinal cross-sectional view of a consumable thermocouple shown as a conventional example.

  A longitudinal sectional view of a consumable thermocouple according to an embodiment of the present invention is shown in FIG. This consumable thermocouple includes a paper basket 1, a ceramic film 2, a chip 3, a protective basket 4, a pair of terminals 5, a thermocouple wire 6, and a heat-resistant covering 7 made by casting. The paperboard 1 is a paper tube that is rolled up to form a thick tube like a conventional paperboard. The ceramic film 2 is a thin sheet made of ceramic, wound around the outer peripheral surface of the paper sheet 1 and integrally joined and fixed so as to cover the entire outer peripheral surface. The chip 3 is a ceramic sintered body and has a disk shape having the same outer diameter as the paper basket 1. A protective rod 4 is fixed to the center of the lower end surface of the chip 3. The protective rod 4 is U-shaped made of a silica glass rod, and is fixed to the chip 3 with both end portions pierced from the lower end surface of the chip 3. The chip 3 is provided with through-holes extending coaxially with the shaft holes at both end portions of the protective rod 4, and is open on the upper end surface of the chip 3.

  The pair of terminals 5 is composed of two metal plates fixed to the central portion of the upper end surface of the chip 3 with a gap therebetween. One end of the thermocouple wire 6 is joined to one terminal 5, the other end passes through one through hole of the chip 3, enters the shaft hole from the opening of one end portion of the protective rod 4, passes through the shaft hole, and the other The other terminal 5 is joined through the other through-hole of the chip 3 from the opening of the end portion.

  The heat-resistant covering 7 is a molded body that is cast with the outer peripheral surface on one end side of the paper sheet 1 covered with the ceramic film 2 and the end surface on one end side of the chip 3 as the mold surface. A castable (cement) used to produce refractories was adopted as the casting material. Note that the surface outside the heat-resistant covering 7 is formed by a mold surface as will be described later. Since the heat-resistant covering 7 is formed by casting, the outer peripheral surface of the ceramic film 2 covering the outer peripheral surface of the paper tube 1 and the heat-resistant covering 7 are integrally formed. Therefore, there is no gap between the heat-resistant coating 7 and the ceramic film 2 and they are integrated. The castable is also cast around the protective rod 4 protruding from the end face on one end side of the chip 3 without any gap, and the chip 3 and the heat-resistant covering 7 are integrated.

  Next, a method for manufacturing the consumable thermocouple of this embodiment will be described. The paper tube 1 has been used conventionally and has a predetermined length. As the ceramic film 2, a thin fibrous sheet impregnated with an inorganic adhesive was used. This sheet was pasted so as to cover the outer peripheral surface of the paper tube 1, and then heated in a dryer to solidify the adhesive and remove the wetness of the paper tube 1, and then dried. Thereafter, the chip 3 in which the protective tube 4, the pair of terminals 5, and the thermocouple wire 4 were incorporated on one end surface of the paper tube 1 was fixed with an inorganic adhesive. The chip 3 in which the protective tube 4, the pair of terminals 5 and the thermocouple wire 4 are incorporated is known in the art and is not particularly new. In this embodiment, one end surface of the paper tube 1 is covered with the chip 3 so that no gap is formed on one end surface of the paper tube 1, that is, the castable is not in contact with the paper tube 1 later.

  As the heat-resistant covering 7, a metal mold 8 schematically shown in FIG. 2 was used. The metal mold 8 is composed of a plurality of parts, which are combined as shown in FIG. This metal mold 8 has a bottomed cylindrical shape, and an upper end is opened. The shaft hole of the metal mold 8 has a two-stage shape with a narrow lower part and a wide upper part. As shown in FIG. 2, the lower portion of the shaft hole has a shape in which the other end portion of the paper tube 1 having the ceramic film 2 can be inserted and fitted. The upper part of the shaft hole has the same inner diameter as the outer diameter of the heat-resistant covering 7, and the protective tube 4 of the chip 3 fixed to the paper tube 1 remains in the shaft hole with the paper tube 1 fitted. It has enough depth.

  As shown in FIG. 2, a paper tube 1 having a chip 3 attached to one end surface and a ceramic film 2 attached to the outer peripheral surface is inserted into the lower part of the shaft hole of the metal die 8, and the shaft hole of the metal die 8 is It was fitted to be coaxial. In this state, a predetermined amount of castable was poured between the outer peripheral surface of the paper tube 1 and the inner surface of the shaft hole. The castable that was poured covered the upper end surface of the tip 3 on the upper side in FIG. 2 and filled up to about ½ of the length of the U-shaped protective tube 4 protruding from the tip 3. In this state, a lid mold 9 shown in FIG. 2 was put on the castable upper surface. The lid mold 9 has a peripheral edge projecting downward, an inner collecting surface of the projecting portion is an inclined surface, and a lower surface of the lid mold 9 forms a trapezoidal space. The central part of the lid mold 9 is a through hole through which the protective tube 4 passes. The upper end of the lid mold 9 placed on the upper surface of the castable is pressed against the upper end of the lid mold 9 so that the protruding peripheral edge of the lid mold 9 is submerged in the castable. The state was raised. In this state, the castable was solidified, and the heat-resistant coated body 7 before drying was molded. The moisture of the castable that permeated the paper tube 1 during casting was very small. Thereafter, the paper tube 1 having the heat-resistant coating 7 was taken out from the metal mold 8 and placed in a drier to dry the heat-resistant coating 7 and the paper tube 1, thereby producing a consumable thermocouple of this embodiment. Drying was also possible in a short time.

  The consumable thermocouple of the present embodiment is fixed by inserting a normal plug (not shown) from the upper end opening of FIG. 1 and covering the protective tube 4 and the protective tube 4 from the liquid surface of the normal molten metal in this state. The lower end of the cover 7 was slightly immersed in the molten metal, and the thermocouple wire 6 in the protective tube 4 was heated to the molten metal temperature to measure the molten metal temperature. In the consumable thermocouple of this embodiment, the heat-resistant covering 7 integrally covers the outer peripheral surface of the paper tube 1 and the upper portion of the tip 3 fixed to the lower end of the paper tube 1 and the protective tube 4 protruding from the tip 3. Moreover, since the heat-resistant coated body 7 as a whole is integrally cast and molded, the heat-resistant coated body 7 is less damaged and has high durability.

  In this embodiment, the ceramic film 2 is attached to the outer peripheral surface of the paper tube 1, but a consumable thermocouple may be used without using the ceramic film 2. In this case, the liquid component contained in the castable penetrates into the paper tube, and it takes time to dry the paper tube, or the surface where the liquid does not penetrate into the outer peripheral surface of the paper tube is used. In some cases, it is required to perform processing.

  In this embodiment, the chip 3 is bonded and fixed to the end face of the paper tube 1, but the chip may be fixed in the shaft hole of the paper tube. Further, the chip can be shaped such that the upper part is accommodated in the shaft hole of the paper tube and the lower part covers the end surface of the paper tube.

  Furthermore, a heat-insulating refractory layer such as ceramic short fibers can be provided between the chip and the molded heat-resistant covering.

Claims (2)

A paper bag, a chip provided at one end of the paper bag, a protective bag protruding from one end of the chip, a pair of terminals provided at the other end of the chip, and one end at one of the terminals A thermocouple wire electrically connected to the other end of the terminal and held in the protective casing, and one end side of the chip and an outer periphery of one end side of the paper casing in a state where the tip end portion of the protective casing protrudes A consumable thermocouple comprising a heat-resistant covering covering the surface,
The consumable thermocouple characterized in that the heat-resistant covering is a molded body that is cast so as to cover an outer peripheral surface on one end side of the paper basket and an end surface on one end side of the chip.   2. The consumable thermocouple according to claim 1, wherein an outer peripheral surface of the paper basket is coated with a ceramic sheet, and the mold forming body constituting the heat-resistant covering is cast in a state of covering the ceramic sheet. .

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