JP7275443B2 - temperature probe - Google Patents

Description

The present invention relates to a temperature measuring probe that measures the temperature of a temperature measuring object.

A temperature measuring probe is used to measure the temperature of a high-temperature object such as molten steel (molten metal). A temperature probe is described, for example, in US Pat.

The temperature measuring probe described in Patent Document 1 includes an internal protective tube having a bottomed tip portion that contacts a temperature measurement object and a cylindrical portion that forms a hollow chamber, and a temperature measurement object that is inserted into the hollow chamber. and a protective sleeve (external protective tube) covering the outer peripheral wall surface of the cylindrical portion. This temperature-measuring probe measures temperature with a thermocouple element through the tip of the internal protective tube by contacting (inserting or immersing) the tip into a temperature-measuring object such as molten steel.
In recent years, there has been a demand for measuring the temperature at a position deeper than the surface (slag line) of molten steel (molten metal). That is, there is a demand for a temperature measuring probe having a long axial length.

However, there is a problem that it is difficult to manufacture a temperature measuring probe having a long axial length. Specifically, the internal protective tube of the temperature measuring probe is manufactured by firing and sintering in a heating furnace. With this manufacturing method, it was not possible to manufacture an inner protective tube longer than the size of the heating furnace. Manufacturing a large furnace just for manufacturing the inner protective tube results in a significant increase in cost.

JP 2011-169798 A

SUMMARY OF THE INVENTION It is an object of the present invention to provide a temperature measuring probe having a long axial length while suppressing an increase in cost.

The temperature-measuring probe of the present invention for solving the above-mentioned problems has a bottomed tubular shape with a closed tip, an internal protective tube formed of a sintered body, and a temperature-measuring probe disposed inside the internal protective tube. A thermometer having a temperature measuring part for measuring the temperature of an object, and an outer protective tube having a cylindrical shape in which the inner protective tube is arranged and made of ceramics, wherein the inner protective tube is , a plurality of small tube members arranged in the axial direction, and engaging means for integrally engaging two adjacent small tube members , wherein the engaging means has a plate shape extending in the axial direction, a locking plate disposed on the outer periphery of the small tube members so as to connect the adjacent ends of the two adjacent small tube members; and a second pin that passes through the locking plate in the thickness direction and has an inner diameter side end that engages with the other small tube member. .

The temperature measuring probe of the present invention is formed by engaging a plurality of small tube members with an internal protective tube made of a sintered body made of a material containing metal and ceramics. According to this configuration, it is possible to form an inner protective tube having a long overall length without using an excessively long small tube member. As a result, the temperature measuring probe of the present invention exhibits the effect of being a temperature measuring probe having a long axial length while suppressing an increase in cost.

The temperature measuring probe of the present invention has a bottomed cylindrical shape with a closed tip, an internal protective tube formed of a sintered body, and a temperature measurement object placed inside the internal protective tube. A thermometer having a temperature measuring part for measurement, and an outer protective tube having a cylindrical shape in which the inner protective tube is arranged and formed of ceramics, the inner protective tube being arranged in the axial direction and an engaging means for integrally engaging two adjacent small tube members, wherein the outer protective tube comprises a plurality of axially arranged tube members and two adjacent small tube members. and a joining material for joining the tubular members, wherein the joining portion where the two tubular members are joined is an engaging portion where the two small tubular members are engaged at a position in the axial direction of the temperature measuring probe. characterized by being different from According to this configuration, when the tip of the temperature measuring probe is immersed in the temperature measurement object (molten metal) and the temperature thereof is measured, even if the molten metal flows, excessive displacement of the tube member and the small tube member will occur. is suppressed, and damage (breakage) of the temperature measuring probe is suppressed.

2 is a cross-sectional view showing the configuration of the temperature measuring probe of Embodiment 1. FIG. FIG. 2 is a cross-sectional view showing a cross section taken along line II-II in FIG. 1; 4 is an enlarged cross-sectional view showing the configuration of the vicinity of the distal end portion of the internal protective tube of the temperature measuring probe of Embodiment 1. FIG. 4 is an enlarged cross-sectional view showing the configuration near the engaging portion of the internal protective tube of the temperature measuring probe of Embodiment 1. FIG. 4 is an enlarged cross-sectional view showing a configuration near an engaging portion of an internal protective tube of a temperature measuring probe of a modified form of Embodiment 1. FIG. FIG. 9 is an enlarged cross-sectional view showing a configuration near an engaging portion of an internal protective tube of the temperature measuring probe of Embodiment 2; FIG. 7 is a cross-sectional view showing a cross section taken along line VII-VII in FIG. 6; FIG. 11 is an enlarged cross-sectional view showing the configuration near the engaging portion of the internal protective tube of the temperature measuring probe of Embodiment 3; FIG. 11 is an enlarged cross-sectional view showing the configuration of the temperature measuring probe of Embodiment 4;

EMBODIMENT OF THE INVENTION Hereinafter, it demonstrates, referring drawings for the form for implementing this invention. In addition, each following form is a specific example for implementing this invention, and this invention is not limited only to following each form.

[Embodiment 1]
A temperature measuring probe 1 of this embodiment has a thermocouple 2 , an inner protective tube 3 , an outer protective tube 4 , a protective castable 5 and a flange 6 . The configuration of the temperature measuring probe 1 of this embodiment is shown in FIGS. 1 to 4. FIG. FIG. 1 is a sectional view showing the configuration of a temperature measuring probe 1 of this embodiment. FIG. 2 is a cross-sectional view showing a cross section taken along line II--II in FIG. FIG. 3 is an enlarged cross-sectional view showing the configuration of the vicinity of the distal end portion 30 (the temperature measuring portion 20 of the thermocouple 2) of the internal protective tube 3. As shown in FIG. FIG. 4 is an enlarged cross-sectional view showing the configuration of the vicinity of the engaging portion of the inner protective tube 3. As shown in FIG.

The temperature measuring probe 1 of this embodiment measures the temperature of the molten metal by immersing the tip portion 30 in molten metal (for example, molten steel) as a temperature measurement object. For example, the tip side of the temperature measuring probe 1 is inserted into an opening in the lid of a container (for example, a tundish) that stores molten metal, and the tip portion 30 is immersed in the molten metal to measure the temperature.

In this embodiment and other embodiments, the side of the distal end portion 30 immersed in the temperature measurement object (molten metal) is defined as the distal side, and the side of the probe head 23 is defined as the proximal side. The axial direction is the direction in which the temperature measuring probe 1 (and the inner protective tube 3 and the outer protective tube 4) extends (specifically, the vertical direction in FIG. 1).

(thermocouple)
The thermocouple 2 is a thermometer having a temperature measuring section 20 that measures the temperature of an object (molten metal) to be measured. The thermocouple 2 is appropriately selected from thermocouples capable of measuring the temperature in the temperature range of the temperature measurement object (molten metal). Thermocouples 2 capable of measuring the temperature of the molten metal include, for example, platinum rhodium type, tungsten rhenium type, iridium rhodium type, alumel chromel type, nickel molybdenum type, and nicrosil type thermocouples.

The thermocouple 2 of this embodiment is a platinum-rhodium type thermocouple. In the platinum-rhodium type thermocouple, the + side of the thermocouple 2 is made of a platinum-rhodium alloy lead wire 2A, the - side is made of a platinum-rhodium alloy or platinum lead wire 2B, and the junction of the two lead wires 2A and 2B is the temperature measuring part. 20 thermocouple. The specific composition and configuration of the platinum-rhodium type thermocouple can be conventionally known compositions and configurations.

The thermocouple 2 is assembled with the temperature measuring portion 20 in contact with the inner peripheral surface 3 a of the tip portion 30 of the internal protective tube 3 . The proximal end of (constituting conductors 2A and 2B) thermocouple 2 is connected to an indicator (not shown) via a probe head 23 (also called a terminal head). As shown in FIGS. 2 and 3, the thermocouple 2 is a substantially cylindrical insulating tube 21 having a pair of through holes 22 (22A, 22B) running in parallel in the axial direction independently of each other. The + side conductor 2A is inserted into 22A, and the - side conductor 2B is inserted into the other through hole 22B. It is At this time, the temperature measuring portion 20 to which the leading ends of the conductors 2A and 2B are joined is in contact with the inner peripheral surface 3a of the leading end portion 30 of the internal protective tube 3. As shown in FIG. Note that the temperature measuring part 20 may not be in contact with the inner peripheral surface 3a of the inner protective tube 3, but may be spaced apart from the inner peripheral surface 3a by a small distance.

The insulating tube 21 is made of an insulating material that can prevent electrical contact between (each of the conductors 2A and 2B of) the thermocouple 2 and the internal protective tube 3 . Ceramics, such as alumina, magnesia, and mullite, can be used as insulating materials. The insulating tube 21 of this embodiment is made of alumina ceramics.

(Internal protection tube)
The internal protective tube 3 is a member having a closed end and a bottomed tubular shape in which the thermocouple 2 can be arranged. The internal protection tube 3 is composed of a distal end-side small tube member 31, a proximal end-side small tube member 32, and an engaging tube 33, as shown in FIGS. The distal side small tube member 31 and the proximal side small tube member 32 correspond to the small tube member in the claims. The inner protective tube 3 is a bottomed cylindrical member whose overall shape is closed such that the distal end portion 30 has a smoothly curved shape, more specifically, a substantially hemispherical shape.
The thermocouple 2 is arranged inside the inner protective tube 3 , and the parts other than the temperature measuring section 20 do not come into contact with the inner protective tube 3 .

The distal small tube member 31 is a member forming the distal end portion 30 of the internal protection tube 3 and is a cylindrical member with the distal end portion 30 closed. The tip end portion 30 of the distal small tube member 31 has the substantially hemispherical shape described above, and the proximal end side thereof has a cylindrical shape. The distal end-side small tube member 31 has a male threaded portion 310 having a screw thread formed on the outer peripheral surface of the end portion on the proximal end side. The tip-side small tube member 31 is formed with a substantially uniform thickness in the radial direction. The distal end-side small tube member 31 is formed such that the proximal end face extends along a plane perpendicular to the axial direction.

The proximal side small tube member 32 is a member forming an end portion of the inner protective tube 3 on the proximal side side and connected to the probe head portion 23 and the flange 6 . The proximal-side small tube member 32 has a cylindrical shape with the same diameter as the cylindrical portion of the distal-side small tube member 31 other than the distal end portion 30 . The proximal-side small tube member 32 has a male threaded portion 320 formed with a screw thread on the outer peripheral surface of the end portion on the distal end side. The proximal end small tube member 32 has a distal end face formed along a plane perpendicular to the axial direction. When the proximal end surface of the distal small tube member 31 and the distal end surface of the proximal small tube member 32 are coaxially abutted, the two opposing end surfaces are in close contact with each other without any gap.

The engagement tube 33 is a cylindrical member that engages and fixes the distal end-side small tube member 31 and the proximal end-side small tube member 32 . The engagement tube 33 has female threaded portions 330 and 331 formed on the inner peripheral surface with threads that screw together with the male threaded portion 310 of the distal small tube member 31 and the male threaded portion 320 of the proximal side small tube member 32. . The engaging tube 33 has a screw thread formed on the entire inner peripheral surface of the cylindrical shape (that is, over the entire length of the engaging tube 33) to be screwed with the male screw portions 310 and 320. As shown in FIG. The engaging tube 33 has a female threaded portion 330 formed with a screw thread to be screwed with the male threaded portion 310 of the distal small tube member 31 on the distal end side. A female threaded portion 331 having a screw thread to be screwed with the male threaded portion 320 of the small tube member 32 is formed. Each of the female threaded portion 330 and the female threaded portion 331 is formed with a length that is half the axial length of the engaging cylinder 33 .

As shown in FIG. 4, the internal protection tube 3 of this embodiment has a distal side small tube member 31 from the distal end side of the engaging tube 33 and a proximal side small tube member 32 from the proximal side of the engaging tube 33, respectively. The threaded portions 310, 320 and the female threaded portions 330, 331 are screwed together. The distal end-side small tube member 31 and the proximal-side small tube member 32 are fixed inside the engagement cylinder 33 at half the length in the axial direction, with their opposing end surfaces being in close contact with each other over the entire surface. In this embodiment, the contact surface between the end faces of the distal end-side small tube member 31 and the proximal end-side small tube member 32 is an engaging portion 34 . In addition, the axial position of the engaging portion 34 in the engaging tube 33 is not limited. As long as it is a position where the distal end-side small tube member 31 and the proximal side small tube member 32 can be engaged and fixed, it may be located on the distal side or the proximal side relative to the present embodiment.
The inner protective tube 3 (specifically, all of the distal side small tube member 31, the proximal side small tube member 32, and the engaging tube 33) is formed of a sintered body. A sintered body is a material that is heat-treated in a heating furnace.
The sintered body is made of at least one of a material containing metal and ceramics (metal-ceramic composite material), Si ₃ N ₄ , and sialon (silicon-alumina nitride).

The internal protective tube 3 of this embodiment is made of cermet. Cermets are materials containing metals and ceramics (metal-ceramic composite materials). Cermet is a material that can satisfy the required hardness and quick response to temperature when used for the temperature measuring probe 1 . The specific material forming the inner protective tube 3, that is, the composition of the cermet, is appropriately selected according to the properties required in the temperature range of the object to be temperature-measured.

As the metal forming the cermet (metal-ceramic composite material), it is preferable to use at least one selected from Mo, W and Ti. As the ceramics forming the cermet, it is preferable to use at least one selected from alumina, zirconia, magnesia, spinel, mullite, silicon carbide and yttria. The metals and ceramics forming the cermet are not limited to these. The cermet of this embodiment is a Mo--ZrO ₂ -based Mo--ZrO ₂ cermet having a high melting point and strength.

The Mo—ZrO ₂ cermet forming the internal protective tube 3 of this embodiment is a composite material of Mo and ZrO ₂ , and the content ratio of Mo and ZrO ₂ is not limited. A composite material containing more Mo than ZrO ₂ is preferable, and when the whole is 100 mass%, Mo:ZrO ₂ is contained in a ratio (mass ratio) of 65 to 90%: 35 to 10%. It is more preferable to have

Since the cermet forming the inner protective tube 3 is excellent in strength and heat transfer, it is preferably a dense body and preferably has a small porosity. Here, the method of measuring the porosity of the cermet is not limited. Conventional measuring equipment can be used. In this embodiment, the porosity is calculated from the apparent density in accordance with JIS R 2205. The cermet preferably has a porosity of 0 to 5% (ie, 5% or less), more preferably 0 to 4% (ie, 4% or less), and 0 to 3% (ie, 3% or less). is more preferable.

In the internal protection tube 3, the distal side small tube member 31, the proximal side small tube member 32 and the engaging tube 33 are all made of the same material. By forming the inner protective tube 3 from one material, the inner protective tube 3 as a whole has the same characteristics. In particular, by using materials with the same coefficient of thermal expansion, damage due to differences in thermal expansion can be suppressed.

The axial lengths of the distal end-side small tube member 31, the proximal end-side small tube member 32, and the engaging tube 33 that form the inner protective tube 3 are not limited. Each of the distal side small tube member 31 and the proximal side small tube member 32 preferably has a length shorter than the internal protective tube of a conventional temperature measuring probe. That is, it is preferable that each of the distal side small tube member 31 and the proximal side small tube member 32 has a length shorter than the length that can be manufactured in a conventional heating furnace.

(External protection tube)
The external protective tube 4 is a cylindrical member with both ends opened. The outer protective tube 4 has the inner protective tube 3 arranged inside (hollow portion of the shaft core). The outer protective tube 4 is formed to have an annular gap (small gap) between its inner peripheral surface and the outer peripheral surface of the inner protective tube 3 when the inner protective tube 3 is arranged inside. The inner diameter of the outer protective tube 4 is larger than the outer diameter of the inner protective tube 3 (the maximum outer diameter, the outer diameter of the engaging tube 33) by the amount of the gap.

The specific shape of the outer protective tube 4 is not limited. The thickness of the outer protective tube 4 is also not limited, and can be the same as the thickness of a conventional temperature measuring probe. The axial length of the outer protective tube 4 is also not limited, and the length is such that the end on the tip side can be immersed in the temperature measurement object (molten metal) when measuring the temperature of the temperature measurement object (molten metal). . When the tip portion 30 of the temperature measuring probe 1 is immersed in the molten metal, the molten metal surface (slag line) of the object to be temperature-measured overlaps the outer peripheral surface of the outer protective tube 4 .

The outer protective tube 4 is made of ceramics. Specific ceramics forming the outer protective tube 4 are appropriately selected depending on the properties (for example, heat resistance, thermal shock resistance, strength) required in the temperature range of the object to be measured. Ceramics include, for example, ceramics containing alumina as a main component. In this embodiment, it is a mixed material in which alumina and carbon are mixed.

In the mixed material of alumina and carbon, the content ratio of alumina and carbon is not limited. It is preferable that the composite material contains more alumina than carbon, and when the total amount of the mixed material is 100 mass%, it contains 65 to 90% alumina and 10 to 35% carbon. preferable. Ceramics containing 65 to 80% alumina and 20 to 35% carbon are more preferable.

The ceramics of the outer protective tube 4 is preferably a porous material having a plurality of pores, and preferably has a porosity of about 1 to 30%. The porosity is preferably about 2 to 25%, more preferably about 5 to 20%. The porosity of the ceramics of the outer protective tube 4 is preferably higher than the porosity of the cermet of the inner protective tube 3 .

The external protective tube 4 is formed by joining a cylindrical distal end side tube member 40 and a cylindrical proximal end side tube member 41 in a coaxial state with a joining material. That is, the outer protective tube 4 is formed by joining a plurality of axially adjacent cylindrical tube members with a joining material.

Both the distal side tube member 40 and the proximal side tube member 41 have a cylindrical shape. The distal tube member 40 and the proximal tube member 41 have cylindrical shapes with the same inner diameter and outer diameter. When the distal side tube member 40 and the proximal side tube member 41 are arranged coaxially adjacent to each other in the axial direction, the inner peripheral surface and the outer peripheral surface form a continuous smooth surface (no unevenness at the joint 42). can.

In the external protective tube 4 , the axial position of the joint 42 where the distal side tube member 40 and the proximal side tube member 41 are joined is the engagement between the distal side small tube member 31 and the proximal side small tube member 32 of the internal protection tube 3 . The position is different from the axial position of the portion 34 . Specifically, the axial position of the joint 42 between the distal end side tube member 40 and the base end side tube member 41 of the outer protection tube 4 is the same as the position of the molten metal when measuring the temperature of the molten metal with the temperature measuring probe 1. It is located on the base end side (upper side in FIG. 1) from the molten metal surface (slag line). The axial position of the joint portion 42 between the distal side tubular member 40 and the proximal side tubular member 41 of the outer protective tube 4 is the position of the engaging portion 34 between the distal side small tubular member 31 and the proximal side small tubular member 32 of the inner protective tube 3. It is located on the tip side (lower side in FIG. 1) from the axial position. That is, when the temperature of the molten metal is measured by the temperature measuring probe 1, the engaging portion 34, the joint portion 42, and the surface of the molten metal are positioned in this order from the proximal side to the distal side.
The distance between the engagement portion 34 and the joint portion 42 (the distance between the axial positions) is not limited. It is preferably 50 mm or more, more preferably 50 to 100 mm, even more preferably 60 to 90 mm.

A bonding material that can bond the two tube members 40 and 41 together can be used as the bonding material that joins the distal tube member 40 and the proximal tube member 41 of the outer protective tube 4 . Examples of this bonding material include cement containing ceramics.

In this embodiment, the outer protective tube 4 joins the distal side tube member 40 and the proximal side tube member 41 with a bonding material, but may be formed from three or more tube members. Furthermore, each pipe member 40, 41 may also be formed by joining axially extending columnar members in the circumferential direction.

The outer protective tube 4 accommodates the inner protective tube 3 in its interior (hollow portion of the shaft core). At this time, the gap between the inner peripheral surface of the outer protective tube 4 and the outer peripheral surface of the inner protective tube 3 is filled with the filler 43 . As the filling material 43, the same material as the bonding material of the outer protective tube 4 can be used. In this embodiment, cement is used as the filler 43 .

(protective castable)
The protective castable 5 is formed in a cylindrical shape as a whole so as to cover the outer peripheral surface of the outer protective tube 4 on the base end side thereof. The protective castable 5 is integrally formed with its inner peripheral surface in close contact with the outer peripheral surface of the outer protective tube 4 . The protective castable 5 is formed so that the outer peripheral surface of the outer protective tube 4 is not exposed. The lower end of the protective castable 5 is located below the surface (slag line) of the molten metal when the temperature measuring probe 1 measures the temperature of the molten metal.

The protective castable 5 is formed by molding a monolithic refractory. A specific material of the monolithic refractory forming the protective castable 5 is not limited. A castable that forms the outer peripheral surface of a conventional temperature probe can be used. In this embodiment, castable cement is used.
The protective castable 5 is formed by molding a monolithic refractory, and is formed of unsintered material particles of the monolithic refractory. Protective castable 5 has a higher porosity than outer protective tube 4 .

(flange)
The flange 6 integrally includes a body portion 60 , an inner tubular portion 62 and an outer tubular portion 63 .
The body portion 60 has a substantially annular plate shape extending in a direction perpendicular to the axial direction. The main body portion 60 has an insertion hole 61 through which the internal protective tube 3 is inserted, formed in a substantially annular axial core portion. The insertion hole 61 is formed with a diameter that allows the internal protective tube 3 to be inserted. In this embodiment, the inner peripheral shape (inner diameter) of the insertion hole 61 substantially matches the outer peripheral shape (outer diameter) of the internal protective tube 3 . When the internal protective tube 3 is inserted into the insertion hole 61, the inner peripheral surface of the insertion hole 61 and the outer peripheral surface of the internal protective tube 3 are in close contact over the entire circumference.

The inner tubular portion 62 is a tubular portion that stands upright from the surface 60a (the surface facing the proximal side) of the main body portion 60 toward the proximal side. The inner tubular portion 62 has a cylindrical shape with an inner diameter that matches the opening shape of the insertion hole 61 . The internal protective tube 3 is inserted (or fitted) inside the inner tubular portion 62 .

The axial length of the inner tubular portion 62 is not limited. In other words, the erected height from the surface 60a of the body portion 60 is not limited. The length in the axial direction of the inner cylindrical portion 62 may be any length that can hold (support or fix) the inner protective tube 3 inserted through the inner cylindrical portion 62 and the insertion hole 61 . The inner tubular portion 62 may be provided with holding means for holding (supporting or fixing) the internal protective tube 3 in the inner tubular portion 62 . In this embodiment, a bonding material is arranged between the inner tubular portion 62 and the internal protective tube 3 to bond (hold) them. As the joining material of this embodiment, a joining material for joining the outer protective tube 4 and the inner protective tube 3 is used.
A proximal end of the inner tubular portion 62 is connected to the probe head 23 .

The outer tubular portion 63 is a tubular portion erected from the rear surface 60b of the main body portion 60 toward the tip side. The outer tubular portion 63 has a cylindrical shape with an inner diameter that matches the outer peripheral shape of the body portion 60 . The inner protective tube 3 is inserted through the outer tubular portion 63 . The outer tubular portion 63 is filled with a bonding material 64 and the outer protective tube 4 and the protective castable 5 are bonded to the flange 6 .

The axial length of the outer tubular portion 63 is not limited. In other words, the erected height from the rear surface 60b of the body portion 60 is not limited. The axial length of the outer tubular portion 63 may be any length that allows the outer protective tube 4 and the protective castable 5 to be joined with the joint material 64 .

As for the flange 6, the heat-resistant material used in the conventional temperature measuring probe may be arranged on the rear surface 60b side of the body portion 60. As shown in FIG. The heat-resistant material is preferably made of a porous ceramic plate. The heat-resistant material is bonded and fixed to the body portion 60 with a bonding material 64 .

The joining material 64 joins and fixes the outer protective tube 4 and the protective castable 5 to the flange 6 . The joining material 64 joins and fixes the outer protective tube 4 and the protective castable 5 in a state in which the end surfaces on the proximal side of the protective castable 5 are in close contact with the back surface 60b of the flange 6 (the end surface of the outer protective tube 4 is pressed against the flange 6). do. A conventional bonding material can be used as the bonding material 64 . In this embodiment, the bonding material 64 is formed by solidifying the cement filled inside the outer tubular portion 63 of the flange 6 .

The body portion 60 may have studs on the rear surface 60b to prevent the bonding material 64 from coming off. The shape, number, etc. of the studs are not limited. If the body portion 60 has a stud, the bonding material 64 is preferably filled so as to surround the stud.

(Production method)
The manufacturing method of the temperature measuring probe 1 of this embodiment is not limited. After manufacturing the inner protective tube 3 and the outer protective tube 4 respectively, they can be manufactured by the same manufacturing method as the conventional temperature measuring probe 1 .
The inner protective tube 3 is formed by forming respective members to be a distal end-side small tube member 31, a proximal end-side small tube member 32, and an engaging tube 33 (specifically, they are fired in a heating furnace to obtain a fired body). Then, male threaded portions 310, 320 and female threaded portions 330, 331 are formed at predetermined end portions (for example, threads are formed with a tap or a die). After that, the male threaded portion 310 and the female threaded portion 330 and the male threaded portion 320 and the female threaded portion 331 are screwed and engaged. As described above, the temperature measuring probe 1 of the present embodiment can be manufactured.

In this embodiment, as shown in FIG. 1, the flange 6 can be formed by welding a heat-resistant metal member having an inner cylindrical portion 62 to a heat-resistant metal member having a body portion 60 and an outer cylindrical portion 63. Although it is formed by joining, it is not limited to this form. The members that become the main body portion 60, the inner tubular portion 62, and the outer tubular portion 63 may be formed and joined integrally.

(effect)
The temperature measuring probe 1 of this embodiment has a bottomed cylindrical shape with a closed tip portion 30, an internal protective tube 3 made of cermet (a material containing metal and ceramics), and an interior of the internal protective tube 3 A thermocouple (temperature measuring means) 2 having a temperature measuring part 20 for measuring the temperature of an object to be measured, and a cylindrical shape in which an internal protective tube 3 is arranged, formed of ceramics and an external protection tube 4 . The inner protective tube 3 includes a distal end side small tube member 31 and a proximal side small tube member 32 (a plurality of small tube members arranged in the axial direction), a distal side small tube member 31 and a proximal side small tube member 32 (two adjacent tube members). and an engaging tube 33 (engaging means) for integrally engaging the small tube member).

In the temperature measuring probe 1 of this embodiment, the engaging means is a male screw portion 310 formed at each of the adjacent ends of the distal side small tube member 31 and the proximal side small tube member 32 (two adjacent small tube members). 320 and a female screw portion 330 screwed into the male screw portion 310 (one male screw portion of the two male screw portions 310, 320) is attached to one end, and the male screw portion 320 (the two male screw portions 310, 320, 320 (the other male threaded portion), and a cylindrical engaging tube 33 having a female threaded portion 331 at the other end thereof.

In the temperature measuring probe 1 of this embodiment, the inner protective tube 3 made of cermet is integrally engaged with the adjacent distal end side small tube member 31 and the proximal end side small tube member 32 with an engaging tube 33 . According to this configuration, the long temperature measuring probe 1 can be manufactured easily and inexpensively.

Specifically, the length of the conventional internal protective tube 3 is limited by the size of the firing furnace for firing the cermet. On the other hand, in the temperature measuring probe 1 of the present embodiment, the distal side small tube member 31 and the proximal side small tube member 32 are integrally engaged and fixed by the engagement tube 33, thereby forming a long internal protective tube made of cermet. 3 can be obtained. Neither the distal side canalicular member 31 nor the proximal side canalicular member 32 needs to be longer than the conventional inner protective tube. The distal side small tube member 31 and the proximal side small tube member 32 can be manufactured using conventional manufacturing methods (manufacturing apparatus, heating furnace). As a result, the temperature measuring probe 1 using the long internal protective tube 3, which has been difficult to manufacture by the conventional method, can be manufactured simply and at low cost.

In this embodiment, the internal protective tube of a conventional temperature measuring probe can be used as the distal end-side small tube member 31, and the proximal end-side small tube member 32 shorter than the distal side small tube member 31 can be used. Then, the inner protective tube 3 can be manufactured by newly designing and manufacturing only the base end small tube member 32 . As a result, the inner protective tube 3 can be manufactured at a lower cost than when the tip side small tube member 31 is also newly designed and manufactured. The distal side small tube member 31 and the proximal side small tube member 32 are not limited in specific shape (size) as long as they have a shape (axial length) capable of forming the inner protective tube 3 as a whole. For example, the axial length of the proximal small tube member 32 is preferably 200 mm or more, more preferably 200 to 500 mm, and even more preferably 250 to 400 mm. Here, the axial length of the proximal side small tube member 32 may be the length from the back surface 60b of the main body portion 60 of the flange 6 .

In the temperature measuring probe 1 of this embodiment, the external protective tube 4 comprises a distal side tube member 40 and a proximal side tube member 41 (a plurality of tube members) arranged in the axial direction, a distal side tube member 40 and a proximal side tube. and a bonding material for bonding the member 41 . A joint portion 42 where the distal side tube member 40 and the proximal side tube member 41 are joined in the outer protective tube 4 is located at a position in the axial direction of the temperature measuring probe 1 that is the distal side small tube member 31 in the inner protective tube 3. It is different from the engaging portion 34 of the proximal side canalicular member 32 . More specifically, the engaging portion 34 of the inner protective tube 3 is positioned closer to the proximal side than the joint portion 42 of the outer protective tube 4 .

According to this configuration, when the tip of the temperature measuring probe 1 of the present embodiment is immersed in the temperature measurement object (molten metal) to measure the temperature, the direction perpendicular to the axial direction (horizontal direction) caused by the flow of the molten metal direction) is applied to the temperature measuring probe 1, damage (breakage) of the temperature measuring probe 1 is suppressed.

Specifically, the temperature measurement object (molten metal, for example, molten steel) whose temperature is to be measured is not stationary when it is stored in the tundish, but flows inside. When the tip of the temperature measuring probe 1 (that is, the tip 30 of the internal protective tube 3) is immersed in molten steel in this state, a force due to the flow of molten steel is applied to the temperature measuring probe 1 . This force is mainly directed laterally (a direction along a plane perpendicular to the axial direction). That is, lateral force is applied to each of the inner protective tube 3 and the outer protective tube 4 of the temperature measuring probe 1 . Each of the inner protective tube 3 and the outer protective tube 4 is fixed at the base end side and is not fixed at the tip end side, and is displaced so that the temperature measuring probe 1 swings around the base end. The force laterally applied to the temperature measuring probe 1 concentrates on the engaging portion 34 of the inner protective tube 3 and the joint portion 42 of the outer protective tube 4 respectively. Since the positions of the engaging portion 34 of the inner protective tube 3 and the joint portion 42 of the outer protective tube 4 are different in the axial direction, stress is not concentrated in the axial direction of the temperature measuring probe 1 . As a result, damage (breakage) of the temperature measuring probe 1 is suppressed.

More specifically, when a lateral force is applied to the internal protective tube 3 , a lateral force is applied to each of the distal side small tube member 31 and the proximal side small tube member 32 . Then, it deforms in the horizontal direction. The amount of deformation in the lateral direction is greater on the distal side than on the proximal side. Stress concentrates on the engaging portion 34 due to this difference in deformation amount. Even if the distal small tube member 31 attempts to deform greatly, further deformation is restricted by the proximal tube member 41 of the outer protective tube 4 . As a result, stress concentrated on the engaging portion 34 can be reduced, and breakage of the inner protective tube 3 can be suppressed. Similarly, even if a lateral stress is applied to the outer protective tube 4 and the tip side tubular member 40 attempts to deform, the deformation is restricted by the inner protective tube 3 (the tip side small tube member 31 thereof). The stress concentrated on the joint portion 42 can be reduced, and breakage of the outer protective tube 4 can be suppressed. As a result, damage (breakage) of the temperature measuring probe 1 is suppressed.

On the other hand, if the axial positions of the joint portions of the inner protective tube 3 and the outer protective tube 4 are the same, when at least one of the tip side small tube member 31 and the tip side tube member 40 tries to deform, the deformation will occur. is not regulated. As a result, stress is concentrated on at least one of the engaging portion 34 of the inner protective tube 3 and the joint portion 42 of the outer protective tube 4, and damage (breakage) occurs at this position. If the axial positions of the joints of the inner protective tube 3 and the outer protective tube 4 are the same as described above, the temperature measuring probe 1 is likely to be damaged (broken).

In the temperature measuring probe 1 of this embodiment, the engaging means of the internal protective tube 3 are formed on the outer peripheral surfaces of the adjacent ends of the distal end side small tube member 31 and the proximal side small tube member 32 that are axially adjacent to each other. A male threaded portion 310, 320 having a male thread, a female threaded portion 330 screwed into one male threaded portion 310 of the two male threaded portions 310, 320, and the other male threaded portion. 320 and a cylindrical engaging cylinder 33 having a female threaded portion 331 that is screwed together.

According to this configuration, the distal side small tube member 31 and the proximal side small tube member 32 form the internal protective tube 3 in which the distal side small tube member 31 and the proximal side small tube member 32 are firmly engaged and fixed with a simple configuration. In addition, the engaging cylinder 33 is configured to engage the ends of the distal small tube member 31 and the proximal small tube member 32, so that even if a lateral stress is applied to the internal protective tube 3, the distal small tube can An engaging tube 33 covering the engaging portion 34 (the portion where the ends are opposed to each other) of the member 31 and the base end small tube member 32 suppresses stress concentration. As a result, the temperature measuring probe 1 of this embodiment can be more reliably prevented from being damaged (broken).

Furthermore, the engaging tube 33 has a cylindrical shape that covers the entire circumference of the end (engaging portion 34) of the distal small tube member 31 and the proximal small tube member 32, and the internal protective tube 3 (temperature measuring probe The above effect can be exhibited regardless of the direction of the stress applied to 1). That is, the temperature measuring probe 1 of this embodiment suppresses damage regardless of the direction of the flow of the temperature measurement object (molten metal) when measuring the temperature of the temperature measurement object (molten metal) with flow. Temperature can be measured. Moreover, even if the flow direction of the temperature measurement object (molten metal) changes while the temperature of the temperature measurement object (molten metal) is being measured, the temperature measuring probe 1 may be damaged (broken). suppressed.

The temperature measuring probe 1 of this embodiment is made of a monolithic refractory and has a protective castable 5 covering the outer peripheral surface of the outer protective tube 4 . According to this configuration, exposure of the outer peripheral surface of the outer protective tube 4 is suppressed, and abrasion damage of the outer protective tube 4 due to molten metal is suppressed. In particular, the protective castable 5 is formed at a position corresponding to the slag line of the molten metal, so that the outer protective tube 4 is prevented from being worn and damaged by solids (slag) on the surface of the molten metal.

[Modification of Embodiment 1]
This embodiment is a temperature measuring probe 1 having the same configuration as that of Embodiment 1 except that the engagement means of the internal protective tube 3 (the configuration near the engagement portion 34) is different. Configurations not specifically mentioned in this embodiment are similar to those of the first embodiment. FIG. 5 is an enlarged cross-sectional view showing the configuration of the vicinity of the engaging portion of the internal protective tube 3 of the temperature measuring probe 1 of this embodiment.

A male threaded portion 310 is formed at the proximal end of the distal small tube member 31 . The distal end-side small tube member 31 is formed so that the outer diameter of the proximal end portion (that is, the portion where the male screw portion 310 is formed) is smaller than that of the other portions. Specifically, as shown in FIG. 5, the distal small tube member 31 is formed in a cylindrical shape with a proximal end portion having a smaller diameter than other portions (excluding the distal end portion 30). A male threaded portion 310 is formed with a screw thread at the end. The outermost diameter of the thread of the male threaded portion 310 is smaller than the outer diameter of the cylindrical portion other than the male threaded portion 310 .

A male threaded portion 320 is formed on the outer peripheral surface of the distal end portion of the proximal side small tube member 32 . The base-side small tube member 32 is formed in a state in which the outer diameter of the tip-side end (that is, the portion where the male screw portion 320 is formed) is smaller than that of the other portions. Specifically, the proximal end small tube member 32 is formed in a cylindrical shape with a diameter smaller than that of the other portion at the end on the distal end side, and forms a male screw portion 320 having a screw thread formed on the outer peripheral surface thereof. there is The outermost diameter of the thread of the male threaded portion 320 is smaller than the outer diameter of the cylindrical portion other than the male threaded portion 320 .

The engagement tube 33 is a cylindrical member that is screwed together with the male threaded portion 310 of the distal small tube member 31 and the male threaded portion 320 of the proximal side small tube member 32 . The engagement tube 33 has the same configuration as the engagement tube 33 of the first embodiment except that the outer diameter and the inner diameter are different. The engagement tube 33 is formed with female screw portions 330 and 331 that screw together with the male screw portions 310 and 320 . In other words, the engagement tube 33 is formed with an inner diameter corresponding to the end portion where the outer diameters of the distal end side small tube member 31 and the proximal side small tube member 32 are reduced.

The engagement tube 33 has the same outer diameter as the distal end-side small tube member 31 and the proximal end-side small tube member 32 . The internal protective tube 3 has a continuous smooth outer peripheral surface (outer peripheral surface without unevenness in the axial direction) when the distal end small tube member 31 and the proximal end small tube member 32 are screwed into the engaging tube 33. None.

(effect)
The temperature measuring probe 1 of this embodiment has the same configuration as that of the first embodiment except for the engagement structure of the internal protection tube 3, and exhibits the same effects as the first embodiment.
In the temperature measuring probe 1 of this embodiment, the inner protective tube 3 has a shape with no irregularities on its outer peripheral surface. According to this configuration, the gap between the outer peripheral surface of the inner protective tube 3 and the inner peripheral surface of the outer protective tube 4 can be reduced. By doing so, the inner protective tube 3 and the outer protective tube 4 can exhibit the effect of mutually restricting deformation, and damage (breakage) of the temperature measuring probe 1 can be further suppressed.

[Embodiment 2]
This embodiment is a temperature measuring probe 1 having the same configuration as that of Embodiment 1, except that the engagement means of the internal protective tube 3 (the configuration in the vicinity of the engagement portion 34) is different. Configurations not specifically mentioned in this embodiment are similar to those of the first embodiment. 6 and 7 are partially enlarged cross-sectional views showing the configuration of the vicinity of the engaging portion of the internal protective tube 3 of the temperature measuring probe 1 of this embodiment. FIG. 7 is a cross-sectional view taken along line VII--VII in FIG.
The internal protective tube 3 has a distal small tube member 31, a proximal small tube member 32, a locking plate 35, and two locking pins 36 (360, 361).
A locking hole 311 for locking a locking pin 36 (360) is opened in the outer peripheral surface of the distal small tube member 31 near the end on the proximal side.
A locking hole 322 for locking the locking pin 36 (361) is opened in the outer peripheral surface of the proximal side small tube member 32 near the end on the distal side.
The locking plate 35 has a plate shape (belt shape) elongated in the axial direction. The locking plate 35 is a plate-shaped (strip-shaped) member arranged in contact with the outer peripheral surface of the inner protective tube 3, and the width direction of the strip-shaped is curved along the circumferential direction.

The locking plate 35 is arranged on the outer periphery of each of the small tube members 31 and 32 so as to connect the ends of the adjacent distal side small tube member 31 and the proximal side small tube member 32 . The locking plate 35 is provided with locking holes 350 and 351 . The locking hole 350 is provided at a radially outward position of the locking hole 311 of the distal small tube member 31 of the locking plate 35, and the locking pin 36 (specifically, the locking pin 360) is inserted therethrough. . The locking hole 351 is provided at a radially outward position of the locking hole 322 of the proximal side small tube member 32 of the locking plate 35, and the locking pin 36 (specifically, the locking pin 361) is inserted thereinto. do.
The locking holes 350, 351 are formed so that the inner diameter thereof matches the outer diameter of the locking pin 36 so that the locking pin 36 (360, 361) is fitted and fixed.

The locking pin 36 (360) is assembled through the locking holes 311 and 350 communicating in the radial direction to lock and fix the distal small tube member 31 and the locking plate 35 . The locking pin 36 (361) is assembled through the locking holes 322 and 351 communicating in the radial direction, and locks and fixes the proximal side small tube member 32 and the locking plate 35. As shown in FIG.

The specific shape of the locking pin 36 (360, 361) is not limited. The locking pin 36 (360, 361) has an outer peripheral shape (specifically, a cylindrical shape) that matches the inner peripheral shape of the locking holes 311, 350 and the locking holes 322, 351. As shown in FIG. The locking pins 36 (360, 361) may have a shape such as a rivet shape in which the head portion (end portion on the radially outer side) is enlarged in diameter.

(effect)
The temperature measuring probe 1 of this embodiment has the same configuration as that of the first embodiment except for the engagement structure of the internal protection tube 3, and exhibits the same effects as the first embodiment.
The engaging means in the temperature measuring probe 1 of this embodiment has a plate-like shape extending in the axial direction, and the adjacent ends of the distal side small tube member 31 and the proximal side small tube member 32 (two adjacent small tube members) A locking plate 35 arranged so as to connect the locking plates 35 and a locking pin that penetrates the locking plate 35 in the thickness direction and whose inner diameter side tip is locked to the tip side small tube member 31 (one small tube member). 360 (first pin) and a locking pin 361 (second pin) which penetrates the locking plate 35 in the thickness direction and whose inner diameter side tip locks to the proximal side small tube member 32 (the other small tube member). ) and According to this configuration, the distal small tube member 31, the proximal small tube member 32, and the locking plate 35 are locked and fixed by the locking pins 36 (360, 361). In other words, the inner protective tube 3 in which the distal end-side small tube member 31 and the proximal end-side small tube member 32 are firmly fixed with a simple structure is obtained.

[Modification of Embodiment 2]
In Embodiment 2, the distal end side small tube member 31 and the proximal side small tube member 32 aligned in the axial direction are locked and fixed by the locking plate 35 and the locking pin 36 (360, 361). The number of locking plates 35 is not limited as long as they can be locked to both the side small tube member 31 and the proximal side small tube member 32 . Two or more locking plates 35 may be provided. When two or more locking plates 35 are used, the locking plates 35 are preferably arranged at equal intervals in the circumferential direction.
The locking plate 35 may have a strip-like shape whose longitudinal direction extends along the axial direction, or a strip-like shape whose longitudinal direction extends spirally along the outer peripheral surface of the inner protective tube 3 .

The locking plate 35 may have a cylindrical shape formed along the entire circumference of the outer peripheral surface of the inner protective tube 3 in the width direction of the strip, or a cylindrical shape with a part cut off in the circumferential direction. That is, the cross-sectional shape of the cross section perpendicular to the axial direction may be circular or C-shaped.

Furthermore, the number of locking pins 36 for locking the locking plate 35 to the distal end-side small tube member 31 and the proximal end-side small tube member 32 is not limited either. As the number of locking pins 36 (and locking holes 311, 350, 322, 351) increases, the number of locking points for locking the locking plate 35 to the distal small tube member 31 and the proximal small tube member 32 increases. As a result, the distal end-side small tube member 31 and the proximal-side small tube member 32 can be fixed to the locking plate 35 more reliably.

[Embodiment 3]
This embodiment is a temperature measuring probe 1 having the same configuration as that of the first embodiment except that the engaging means (configuration of the engaging portion) of the internal protective tube 3 is different. Configurations not specifically mentioned in this embodiment are similar to those of the first embodiment. FIG. 8 shows the configuration of the vicinity of the engaging portion of the internal protective tube 3 of the temperature measuring probe 1 of this embodiment.

The internal protective tube 3 has a male threaded portion 310 formed at the proximal end of the distal small tube member 31 and a female threaded portion 321 formed at the distal end of the proximal small tube member 32 . The male threaded portion 310 and the female threaded portion 321 are screwed together to form the internal protective tube 3 in which the distal side small tube member 31 and the proximal side small tube member 32 are integrally engaged and fixed.

As in the modified form of the first embodiment, the distal small tube member 31 has a reduced diameter at the proximal end, and a male threaded portion 310 is formed on the outer peripheral surface thereof. Specifically, as shown in FIG. 8, the distal small tube member 31 is formed in a cylindrical shape with a proximal end portion having a smaller diameter than other portions (excluding the distal end portion 30). A male threaded portion 310 is formed in the . The outermost diameter of the male thread of the male threaded portion 310 is smaller than the outer diameter of the cylindrical portion other than the male threaded portion 310 .

A female threaded portion 321 that is screwed into the male threaded portion 310 is formed on the inner peripheral surface of the distal end portion of the proximal side small tube member 32 . Specifically, as shown in FIG. 8, the proximal end small tube member 32 is formed in a cylindrical shape with an inner diameter larger at the end on the distal end side than at the other portion, and the inner circumference of the enlarged diameter portion A female screw portion 321 is formed on the surface.

Each of the distal side small tube member 31 and the proximal side small tube member 32 is formed with a male threaded portion 310 and a female threaded portion 321 so as to form a continuous and smooth outer peripheral surface when the inner protective tube 3 is formed. The portions (excluding the tip portion 30) that are not in contact with each other are formed to have the same outer diameter. When the internal protective tube 3 is formed by screwing the male threaded portion 310 and the female threaded portion 321 together, the inner peripheral surface and the outer peripheral surface of the internal protective tube 3 are continuous smooth surfaces (irregularities in the axial direction). surface).
In this embodiment, the male threaded portion 310 and the female threaded portion 321 are formed on the distal end-side small tube member 31 and the proximal side small tube member 32, respectively. The portion and internal thread may be formed on opposite canalicular members, respectively. Specifically, a female screw portion may be formed on the proximal end of the distal small tube member 31 and a female screw portion may be formed on the distal end of the proximal small tube member 32 .

(effect)
The temperature measuring probe 1 of this embodiment has the same configuration as that of the first embodiment except for the engagement structure of the internal protection tube 3, and exhibits the same effects as the first embodiment.
In the temperature measuring probe 1 of this embodiment, the engaging means is the male threaded portion 310 of the distal small tube member 31 (the male threaded portion formed at the end of one of the two adjacent small tube members). , the female threaded portion 321 of the proximal side canalicular member 32 (the female threaded portion formed at the end of the other of the two adjacent canalicular members and screwed with the male threaded portion); consists of According to this configuration, the distal end side small tube member 31 and the proximal side small tube member 32 can be firmly engaged and fixed with a simple configuration.
Furthermore, as in the modified form of Embodiment 1, the gap between the outer peripheral surface of the inner protective tube 3 and the inner peripheral surface of the outer protective tube 4 can be reduced, and the inner protective tube 3 and the outer protective tube 4 can be separated. can exhibit the effect of mutually restricting deformation.

[Embodiment 4]
The temperature-measuring probe of this embodiment is the temperature-measuring probe 1 having the same configuration as that of the first embodiment except that the internal protective tube 3 is formed of three small tube members. Configurations not specifically mentioned in this embodiment are similar to those of the first embodiment. FIG. 9 shows the configuration of the internal protective tube 3 of the temperature measuring probe 1 of this embodiment.

The inner protective tube 3 is formed by engaging and fixing a distal end-side small tube member 31, an intermediate small tube member 37, and a proximal-side small tube member 32 arranged along the axial direction. In the inner protective tube 3, the engaging means between the distal small tube member 31 and the intermediate small tube member 37 and the engaging means between the proximal side small tube member 32 and the intermediate small tube member 37 are both the same engaging means as in the first embodiment. It is the engagement cylinder 33 as. That is, the small tube members 31, 32, 37 are engaged and fixed by screwing together the male threaded portion at the end of each of the small tube members 31, 32, 37 and the female threaded portion of the engaging tube 33. .

The intermediate small tube member 37 is a cylindrical member similar to the proximal side small tube member 32 of the first embodiment, except that male threaded portions are formed at both ends in the axial direction. The male threaded portions at both ends of the intermediate small tube member 37 have the same configuration as the male threaded portions 310 and 320 of the first embodiment.

The number of intermediate tubule members 37 is not limited. It is good also as two or more plurality. Each of the two or more intermediate small tube members 37 can be engaged and fixed by screwing together the male threaded portion and the female threaded portion of the engaging tube portion, as in the first embodiment.

(effect)
In this embodiment, the engaging means between the distal small tube member 31 and the intermediate small tube member 37 and the engaging means between the proximal side small tube member 32 and the intermediate small tube member 37 are formed in the same manner as in the first embodiment. exhibit the same effect as
Since the temperature measuring probe 1 of this embodiment has the intermediate small tube member 37, it is possible to form the internal protective tube 3 that is longer than the internal protective tube of the first embodiment. That is, the temperature measuring probe has a longer axial length. That is, the temperature can be measured at a deeper position from the surface (slag line) of the temperature measurement object (molten metal) than with the temperature measurement probe of the first embodiment.

In this embodiment, the engaging means of the distal end side small tube member 31 and the intermediate small tube member 37 and the engaging means of the proximal side small tube member 32 and the intermediate small tube member 37 are the engaging means of the first embodiment. It is not limited to this engagement means. Any engaging means can be selected from each of the above forms. A plurality of different engaging means may be used with one temperature measuring probe 1 .

[Other variations]
Although the outer protective tube 4 has a cylindrical shape in each of the above embodiments, it is not limited to this shape. The outer protective tube 4 may have a cylindrical shape with a bottom that accommodates the inner protective tube 3 inside. For example, like the internal protection tube 3, the tip may be closed.
The protective castable 5 also has a cylindrical shape covering the outer circumference of the outer protective tube 4, but is not limited to this shape. The protective castable 5 may have a shape that covers the outer peripheral surfaces of the inner protective tube 3 and the outer protective tube 4 .

1: Temperature measuring probe 2: Thermocouple 20: Temperature measuring part 21: Insulating tube 22: Through hole 3: Internal protection tube 30: Tip part 31: Tip side small tube member 32: Base end side small tube member , 33: engagement tube, 34: engagement portion, 35: locking plate, 36: locking pin, 37: intermediate small tube member 4: external protective tube, 40: distal side tube member, 41: proximal side tube member , 42: joint, 43: filler, 5: protective castable, 6: flange

Claims (9)

an internal protective tube having a bottomed cylindrical shape with a closed tip and formed of a fired body;
a thermometer having a temperature measuring part for measuring the temperature of an object to be measured, arranged inside the internal protective tube;
an outer protective tube made of ceramics and having a tubular shape for disposing the inner protective tube inside;
has
The internal protection tube has a plurality of small tube members arranged in the axial direction and an engaging means for integrally engaging two adjacent small tube members,
The engaging means is
a locking plate having a plate shape extending in the axial direction and arranged on the outer circumference of the small tube member so as to connect the adjacent ends of the two adjacent small tube members;
a first pin penetrating through the locking plate in the thickness direction and having a tip on the inner diameter side locked to one of the small tube members;
a second pin penetrating through the locking plate in the thickness direction and having an inner diameter side tip locked to the other small tube member;
A temperature measuring probe comprising : The outer protective tube has a plurality of tube members arranged in the axial direction and a joining material for joining two adjacent tube members,
2. The temperature measuring probe according to claim 1 , wherein the joining portion where the two tubular members are joined differs in position in the axial direction of the temperature measuring probe from the engaging portion where the two small tubular members are engaged. an internal protective tube having a bottomed cylindrical shape with a closed tip and formed of a fired body;
a thermometer having a temperature measuring part for measuring the temperature of an object to be measured, arranged inside the internal protective tube;
an outer protective tube made of ceramics and having a tubular shape for disposing the inner protective tube inside;
has
The internal protection tube has a plurality of small tube members arranged in the axial direction and an engaging means for integrally engaging two adjacent small tube members,
The outer protective tube has a plurality of tube members arranged in the axial direction and a joining material for joining two adjacent tube members,
A temperature measuring probe, wherein a joint portion where the two tubular members are joined is different in position in the axial direction of the temperature measuring probe from an engaging portion where the two small tubular members are engaged. The engagement means are
external threads formed on each of adjacent ends of two adjacent canalicular members;
A tubular engagement member having at one end a female threaded portion that is screwed into one of the two male threaded portions and at the other end with a female threaded portion that is screwed into the other of the two male threaded portions. with a joint tube,
The temperature measuring probe according to claim 3, comprising : The engagement means are
a locking plate having a plate shape extending in the axial direction and arranged on the outer circumference of the small tube member so as to connect the adjacent ends of the two adjacent small tube members;
a first pin penetrating through the locking plate in the thickness direction and having a tip on the inner diameter side locked to one of the small tube members;
a second pin penetrating through the locking plate in the thickness direction and having an inner diameter side tip locked to the other small tube member;
The temperature measuring probe according to claim 3, comprising : each of the two adjacent canalicular members has an end face formed along a plane perpendicular to the axial direction;
The temperature measuring probe according to any one of claims 1 to 5, wherein the two opposing end surfaces are engaged in close contact. The engagement means are
a male threaded portion formed at the end of one of the two adjacent small tube members;
a female threaded portion formed at the end of the other small tube member and screwed with the male threaded portion;
The temperature measuring probe according to claim 3, comprising : The temperature measuring probe according to any one of claims 1 to 7, wherein the sintered body is made of at least one of a composite material of metal and ceramics, Si ₃ N ₄ and sialon. The temperature measuring probe according to any one of claims 1 to 8 , comprising a protective castable made of a monolithic refractory and covering the outer peripheral surface of the outer protective tube.

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