JPH02242573A - Electrical insulating terminal structure for high temperature shield wire - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an electrically insulated terminal structure for high-temperature shielded wires,
In particular, the present invention relates to an electrically insulating terminal structure for a high-temperature shielded wire, which is suitable for increasing strength when used in a high-temperature atmosphere or in an environment with severe temperature changes.

[Prior Art] For example, when a sensor such as a high-temperature strain gauge is installed on a high-temperature side and a measuring instrument is installed on a low-temperature side to perform an autopsy on the form of an object to be measured, the sensor and the measuring instrument are placed at a high temperature. Connect with shielded wire.

FIG. 6 is a side view showing an example of a high-temperature shield wire.

The high-temperature shielded wire shown in FIG. 6 consists of a sheathed wire 1, an electrically insulated terminal 5 provided at the high-temperature end of the sheathed wire, and an electrically insulated terminal 5 provided at the low-temperature end of the sheathed wire. relay connector] 4.

The electrically insulated terminal 5 is configured to connect the core wire of the sheathed wire 1 and the sensor (not shown), usually via a sensor connection line.

The relay connector 14 is adapted to connect a measuring instrument (not shown) directly or via an extension coat.

Next, FIG. 7 is a longitudinal sectional view showing a part of the sheath wire and a conventional electrically insulated terminal.

As shown in FIG. 7, the sheath wire 1 is connected to a metal clad tube 2.
, a high-temperature/electrical insulating material 3 loaded inside this, and a metal core wire 4 that is inserted into the inside and transmits an electrical signal. This sheath wire]- has a thin outer diameter of, for example, 1.5n+m, and can be easily bent and used. Further, in this sheath wire 1, the high temperature/electrical insulating material 3 is formed of oxidized magnesila 11, and the core wire 4
is protected by the high-temperature/electrical insulating material 3, so there is little performance deterioration due to oxidation.

The conventional electrically insulating terminal 5 shown in FIG. It is composed of a metal bushing 8 that is fitted together. One end of the metal tube 7 is brazed to the electrically insulating tube 6, and the end of the metal clad tube 2 of the sheath wire 1 is inserted and welded to the other end. The welded portion is indicated by the reference numeral 11. One end of the metal bushing 8 is brazed to the electrically insulating tube 6, and the core wire 4 of the sheath wire 1 is inserted through the other end. The core wire 4 and the sensor connection wire 13 are connected by welding on the outer end surface of the metal bushing 8, and the insertion hole for the core wire provided in the metal bushing 8 is sealed by the welding. Note that the brazed portion between the metal bushing 8 and the electrically insulating tube 6 is designated by the reference numeral 10.
The welded part between the core wire 4 and the sensor connection wire 13 is indicated by the symbol 12.
It is shown in

In the conventional electrically insulating terminal 5, the electrically insulating tube 6 made of ceramic prevents the metal cladding tube 2 of the sheathed wire 1 from coming into contact with the core wire 4.

Further, in this electrically insulating terminal 5, a metal tube 7 is fitted to the outside of one end of the electrically insulating tube 6, the electrically insulating tube 6 and the metal tube 7 are brazed, and the metal tube 7 and the sheath wire ]−
The metal cladding tube 2 is welded and sealed. Further, a metal bushing 8 is fitted to the outside of the other end of the electrically insulating tube 6, the electrically insulating tube 6 and the metal bushing 8 are brazed, and the metal bushing 8 and the end of the core wire 4 of the sheathed wire 1 are connected to each other. and the sensor connection wire 13 are welded together, and the insertion hole for the core wire is sealed. Therefore, moisture can be prevented from entering the electrically insulating terminal 5.

In this electrically insulating terminal 5, since the coefficient of linear expansion of the metal tube 7 and the metal bushing 8 is larger than that of the electrically insulating tube 6 made of ceramics, the outside of the electrically insulating tube 6 is exposed during the temperature rising process during use. Since the metal tube 7 and metal bushing 8 fitted into the electrically insulating tube 6 expand in the diametrical direction, no direct load acts on the electrically insulating tube 6. On the other hand, during the cooling process, the metal tube 7
Since the metal bushing 8 contracts in the diametrical direction, a compressive load acts on the electrically insulating tube 6. However, the ceramic ring electric insulating tube 6 has a high strength against compressive loads. Therefore, this electrically insulating terminal 5 has high strength when used in a high temperature atmosphere and in an environment with severe temperature changes.

In addition, as a high-temperature shielded wire which is terminal-treated with this type of electrically insulated terminal, the conventional GV-PT.

ANER (UK) product catalog (HIGHTEMP
ERATURE CABLE).

[Problems to be Solved by the Invention] However, in the conventional electrically insulating terminal, the ceramic ring electrically insulating tube 6 is fitted inside the metal tube 7 and the metal bushing 8, so the electrical insulation is relatively poor. The diameter of the tube 6 becomes smaller. As a result, there was a problem in that the strength was low against external forces.

Therefore, if the diameter of the electrically insulating tube 6 made of a ceramic ring is increased, the strength will be increased, but if the electrically insulating tube 6 is formed with a large diameter and the metal tube 7 and metal bushing 8 are fitted on the outside, the electrically insulating There is a problem that the entire size of 5 becomes large.

The first object of the present invention is to improve the electrical insulation, heat resistance, moisture proofing properties, and usability in an environment with large temperature changes of an electrically insulating terminal by combining a ceramic ring electrically insulating tube, a metal tube, and a metal bushing. It is an object of the present invention to provide an electrically insulating terminal structure for a high-temperature shielded wire that is compact and has high strength against external forces while taking advantage of its excellent properties.

The second object of the present invention is to connect the electric insulating tube of the ceramic ring to the metal tube and metal bushing by brazing.
An object of the present invention is to provide an electrically insulating terminal structure for a high-temperature shielded wire that can be made even stronger.

A third object of the present invention is to provide an electrically insulating terminal structure for a high-temperature shielded wire that can reliably connect a core wire of a sheathed wire and a sensor connection wire within a metal bushing.

Furthermore, a fourth object of the present invention is to provide an electrically insulated terminal structure for a high-temperature shielded wire, which has a sensor connection wire that has high rigidity and can easily connect a sensor lead wire.

A fifth object of the present invention is to provide an electrically insulating terminal structure for a high-temperature shielded wire, which can further increase the strength of the ceramic ring electrically insulating tube.

[Means for Solving the Problem] The first object is to connect an electrically insulating terminal for connecting a core wire of a sheath wire and an object to be connected such as a sensor to an electrically insulating tube made of a ceramic ring and an electrically insulating terminal of this electrically insulating tube. It consists of a metal tube fitted inside one end and a metal bushing having a core wire insertion hole and fitted inside the other end of the electrically insulating tube, brazing, fitting and welding the end of the metal clad tube of the sheath wire to the inside of the metal tube,
The metal bushing is brazed to an electrically insulating tube, the core wire of the sheath wire is inserted into the metal bushing, and the core wire and the object to be connected are welded on the outer end surface of the metal bushing, and an insertion hole for the core wire is formed. This is achieved by sealing it.

The second object is achieved by providing a stepped portion in the brazed portion of the metal tube and the metal bushing in the electrically insulating tube, and further includes: This can also be achieved by forming a tapered surface.

The third purpose is to create a concentric space inside the metal bushing.
- is provided with an insertion hole for the core wire and a connection hole for connecting the core wire and the sensor connection wire; the core wire of the sheath wire is introduced into the connection hole through the insertion hole and welded within the connection hole; This is achieved by inserting a sensor connection line and connecting the core wire and the sensor connection line.

The fourth object is achieved by forming the sensor connection line from a highly rigid metal, and by forming the portion of the sensor connection line that protrudes outside the metal bush into a plate shape.

The fifth object is achieved by embedding a mesh metal wire inside the electrically insulating tube.

[Function] In the present invention, a metal tube is brazed to one end of a ceramic electric insulating tube, and a metal clad tube of a sheath wire is fitted and welded to the inside of the metal tube. A metal bushing is brazed to the other end, the core wire of the sheathed wire is inserted into the insertion hole provided in the metal bushing, and the end of the core wire and the end of the object to be connected are welded, and this welded part Since the insertion hole of the core wire is sealed, the electrical insulation terminal, which is a combination of a ceramic electrical insulation tube, a metal tube, and a metal bushing, has excellent electrical insulation, heat resistance, moisture resistance, and can be used in environments with large temperature changes. The excellent properties such as ease of use can be utilized as is.

Further, in the present invention, a metal tube is fitted and brazed inside one end of the electrically insulating tube made of ceramics, and a metal bushing is fitted and brazed inside the other end of the electrically insulating tube. Therefore, the diameter of the ceramic electric insulating tube can be made relatively large. Therefore, the strength of the ceramic electrically insulating tube against external forces can be increased without changing the outer diameter of the electrically insulating terminal.

Furthermore, in the present invention, a stepped portion or a tapered surface is provided at the brazed portion of the metal tube and the metal bushing in the electrically insulating tube. Thereby, the volume of the brazed portion can be increased. As a result, the brazed portion can absorb the difference in thermal expansion in the diametrical direction due to the difference in linear expansion coefficient between the ceramic electrically insulating tube, the metal tube, and the metal bushing. Since the thermal stress of the joint between the metal tube and the metal bushing due to brazing can be suppressed to a low level, the strength of the joint can be increased.

Further, in the present invention, a core wire insertion hole and a connection hole for connecting the core wire and the sensor connection wire are provided concentrically inside the metal bush. Then, the core wire of the sheath wire is introduced into the connection hole through the insertion hole, the end of the sheath wire is welded once within the connection hole, and then the sensor connection wire is inserted into the connection hole, and the core wire and the sensor connection wire are connected. There is. As a result, even if the core wire of the sheath wire is made thinner, the core wire and the sensor connection wire can be reliably connected within the connection hole, making it possible to reduce the outer diameter of the sheath wire and perform wiring work of the sheath wire easily. becomes.

Furthermore, in the present invention, the sensor connection line is made of metal with high rigidity, and the portion that protrudes to the outside of the metal bushing is formed into a plate shape. Thereby, the strength of the sensor connection wire protruding to the outside of the metal bushing can be increased, and furthermore, the sensor lead wire can be easily connected to the plate-shaped portion by welding.

In addition, in the present invention, a mesh metal wire is buried inside the ceramic electric insulating tube, and the brittle nature of the ceramic is reinforced with the mesh metal wire, so that the strength of the electric insulation tube against external forces is further increased. can do.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view showing an end portion of a sheathed wire and an embodiment of the electrically insulating terminal structure of the present invention.

The sheathed wire 1 shown in FIG. 1 is composed of a metal cladding tube 2, a high temperature/electrical insulating material 3 loaded inside the tube, and a metal core wire 4.

The metal clad tube 2 and the core wire 4 are made of stainless steel or stainless steel (trade name: Inconel).

The high temperature/electrical insulating material 3 is made of magnesium oxide.

The sheath wire]- is about 700 in this example.
Even when used in a high-temperature atmosphere of .degree. C. or higher, it is configured such that electrical signals can be transmitted through the core wire 4, which is an electrical signal transmission line, without being affected by external electrical noise.

The electrically insulating terminal shown in FIG. 1 includes an electrically insulating tube 15, a metal tube 18, and a metal bushing 19.

The electrically insulating tube 15 is made of ceramics. Steps 16 and 17 are provided inside the end of the electrically insulating tube 15.
is formed, and a metal film is applied to each step portion 16, 17 by metallization treatment.

The metal tube 18 and the metal bushing 19 are made of a material having a linear expansion coefficient approximately intermediate between that of the metal clad tube 2 and core wire 4 of the sheath wire and the linear expansion coefficient of the electrically insulating tube 15, such as Kovar. It is made of wood.

Between the metal tube 18 and the inner peripheral surface of the electrically insulating tube 15,
It is manufactured to have an outer diameter that can form a circumferential gap that can absorb the difference in thermal expansion in the diametrical direction between the metal tube 18 and the electrically insulating tube 15. The metal tube 18 also has an inner diameter that can form a gap between the sheath wire 1 and the inner peripheral surface of the metal clad tube 2 that can absorb the difference in thermal expansion in the diametrical direction between the metal tube 18 and the metal clad tube 2. It is manufactured in. The metal tube 18 is fitted inside one end of the electrically insulating tube 15 and is coupled to the electrically insulating tube 15 by brazing at the stepped portion 16, with the brazed portion designated by 20. show. Further, an end portion of the metal clad tube 2 of the sheath wire 1 is fitted inside the metal tube 18,
The metal cladding tube 2 and the metal tube 18 are connected by welding, and the welded portion is indicated by reference numeral 22.

The metal bushing 19 is manufactured to have an outer diameter that can form a gap between the metal bushing 19 and the inner peripheral surface of the electrically insulating pipe 15 that can absorb the difference in thermal expansion in the diametrical direction between the metal bushing 19 and the electrically insulating pipe 15. ing. This metal bushing 19 is provided with an insertion hole 23 for the core wire of the sheath wire 1, extending through the metal bushing 19 in the axial direction. Further, the metal bushing 19 is connected to the electrically insulating tube 1.
5 and are connected by brazing at the stepped portion 17, and the brazing portion is indicated by reference numeral 21.

The core wire 4 of the sheath wire 1 is inserted into the insertion hole 23 provided in the metal bushing 19, and the end of the core wire 4 and the sensor connection wire 24 are connected by welding at the outer end surface of the metal bushing 19. This welded portion 25 allows the insertion hole 23 to
is sealed.

In the embodiment shown in FIG. 1, a metal tube 18 is brazed to one end of an electrically insulating tube 15 made of ceramic, and the end of the metal clad tube 2 of the sheath wire 1 is fitted into the inside of this metal tube J8. At the same time, a metal bushing 19 is brazed to the other end of the electrically insulating tube 5, and the core wire 4 of the sheathed wire 1 is inserted into the insertion hole 23 provided in the metal bushing 19. and the sensor connection wire 24 are welded together, and the insertion hole 23 is sealed by this welded portion 25. As a result, an electric insulating tube 15 made of ceramics and a metal tube 1
8 and metal bushing 19, the electrically insulated terminal has electrical insulation properties to prevent contact between the metal cladding tube 2 of the sheathed wire l and the core wire 4, heat resistance, moisture resistance to prevent moisture from entering from the outside, and temperature change. It is possible to take advantage of its excellent properties such as ease of use in environments with large turbulence.

In addition, in this embodiment, an electric insulating tube 15 made of ceramics is used.
A metal tube 18 is fitted inside one end and brazed, and a metal bushing 19 is fitted and brazed inside the other end of the electrically insulating tube 15. Therefore, the diameter of the electrically insulating tube 15 can be increased without changing the outer diameter of the electrically insulating terminal, and thereby the strength of the electrically insulating tube 15 against external forces can be increased.

Further, in this embodiment, step portions 16 and 17 are provided at both ends of the electrically insulating tube 15, a metal tube 18 is brazed at the step portion 16, and a metal bushing 19 is brazed at the other step portion 17. This increases the volume of the brazed portions 20 and 21. As a result, the brazed portions 20 and 21 can absorb the difference in thermal expansion in the diametrical direction due to the difference in linear expansion coefficient between the ceramic electrically insulating tube 15, the metal tube 18, and the metal bushing 19. Therefore, when used in a high temperature atmosphere, the electrical insulation tube 15 and the metal tube 1
8 and the brazed part 2 which is the joint part of the metal bush 19
The strength of 0.21 can be increased.

Furthermore, in this embodiment, the metal tube] 8 and metal bushing 19 have a linear expansion coefficient that is approximately intermediate between that of the metal clad tube 2 and core wire 4 of the sheath wire 1 and that of the electrically insulating tube 15. Since they are made of a material, the difference in thermal expansion in the diametrical direction between these members can be made relatively small. A gap is provided between the tube 18 and the electrically insulating tube 15 and between the metal bushing 19 and the electrically insulating tube 15 to absorb the difference in thermal expansion in the diametrical direction due to the difference in coefficient of linear expansion. When used in an atmosphere, thermal stress generated between each member can be suppressed to a small level.

Next, FIG. 2 is a longitudinal sectional view showing another embodiment of the present invention.

In the embodiment shown in FIG. 2, in contrast to the embodiment shown in FIG. 1, tapered surfaces 26 and 27 are formed on the inside of both ends of the electrically insulating tube 15 instead of the stepped portions.

A metal tube 18 is brazed at the tapered surface 2G, and a metal bushing 19 is brazed at the other tapered surface 27. These brazed portions are designated by reference numeral 28.
29.

Also in the embodiment shown in FIG. 2, the brazed portion 28.
The volume of 29 can be increased. Therefore, when used in a high-temperature atmosphere, it is possible to suppress the thermal stress at the joint between the electrically insulating tube 15, the metal tube 18, and the metal bushing 19 due to brazing, thereby increasing the strength of the joint. becomes.

Regarding the operation of the other configuration 2 of the embodiment shown in FIG. 2,
This is similar to the embodiment shown in FIG. 1 above.

Next, FIG. 3 is a longitudinal sectional view showing another embodiment of the present invention,
FIG. 4 is a perspective view of the sensor connection line.

In the embodiment shown in FIGS. 3 and 4, a sensor connection wire 30 is attached to the outer end surface of the metal bushing 19.

The sensor connection line 30 includes a short cylindrical first portion 31 and a plate-shaped second portion 32. Further, this sensor connection line 30 is made of a material with high rigidity, such as stainless steel or Stella 1 Nos. mild steel.

On the other hand, a sheath wire 1 is attached to the outer end of the metal bush 19.
A connection hole 33 between the core wire 4 of the sheath wire 1- and the first portion 31 of the sensor connection wire 30 is concentrically with the insertion hole 23 for the core wire.
is provided.

The core wire 4 of the sheath wire 1 is introduced into the connection hole 33 through the insertion hole 23, and the ends of the core wire 4 are welded once inside the connection hole 33. The welded portion is designated by the reference numeral 34.

Next, insert the first portion 31 of the sensor connection wire 30 into the connection hole 33, connect the core wire 4 of the sheathed wire and the first portion 31 of the sensor connection wire 30, and then The base of the second part 32 is connected to the metal bushing 19.
weld to the outer end face of the The welded portion is designated by the reference numeral 35. Then, in the second portion 32 of the sensor connection line 30,
Weld and connect the sensor lead wires (none of which are shown).

In the embodiment shown in FIGS. 3 and 4, even if the core wire 4 of the sheath wire is made thinner, the core wire 4 and the first portion 31 of the sensor connection wire 30 are connected within the connection hole 33 of the metal bushing 19. Since the outer diameter of the sheathed wire 1 can be made thinner, the wiring work of the sheathed wire 1, that is, the routing of the sheathed wire 1, can be made easier, and the sheathed wire]. It is possible to eliminate disconnection of the core wire 4 when connecting the core wire 4 and the lead wire of the sensor by spot welding or the like.

Furthermore, since the second portion 32 of the sensor connection line 30 is formed into a plate shape, the sensor connection line 30 and the sensor lead wire can be easily connected by welding.

Another configuration of the embodiment shown in FIGS. 3 and 4.

The operation is similar to the embodiment shown in FIG. 1 above.

Next, FIG. 5 shows a different embodiment of the present invention.
FIG. 3 is a cross-sectional view of the electrically insulating tube taken in a direction perpendicular to the axial direction.

In the embodiment shown in FIG. 5, a mesh metal wire 36 is embedded inside an electrically insulating tube 15 made of ceramic.

This reduces the brittle nature of ceramics to the mesh metal wire 36.
Since the electrically insulating tube 15 can be reinforced with , the strength against external forces can be further increased.

According to the invention described in [Claims of the present invention explained above],
A metal tube is brazed to one end of a ceramic electric insulating tube, and a metal insulating tube of sheathed wire is fitted and welded to the inside of this metal tube, while a metal bushing is attached to the other end of the electric insulating tube. The core wire of the sheathed wire is inserted into the insertion hole provided in this metal bushing, and the end of this core wire and the end of the object to be connected are welded. Since the holes are sealed, the combination of ceramic electrically insulating tubes, metal tubes, and metal bushings improves the electrical insulation, heat resistance, moisture resistance, and usability of electrically insulated terminals in environments with large changes in furnishings. In addition to being able to take advantage of its excellent properties, it is also possible to fit a metal tube inside one end of a ceramic electrically insulating tube and braze it, and then fit a metal bushing inside the other end of the electrically insulating tube. Since the structure is such that the diameter of the ceramic electrically insulating tube can be made relatively large, the external diameter of the electrically insulating terminal does not have to be changed, and the external force of the ceramic electrically insulating tube can be increased. This has the effect of increasing the strength against.

Further, according to the invention set forth in claim 2 of the present invention, a stepped portion is provided in the brazed portion of the metal tube and the metal bush in the electrically insulating tube, and further according to the invention set forth in claim 3 of the present invention, , a tapered surface is provided at the brazed portion of the metal tube and the metal bushing in the electrical insulating tube, and in either case, the volume of the brazed portion can be increased, and therefore the brazed portion allows the ceramic It can absorb the thermal difference in the diametrical direction due to the difference in linear expansion coefficient between the electrically insulated tube, the metal tube, and the metal bushing, and when used in a high-temperature atmosphere, the brazing of the electrically insulated tube, the metal tube, and the metal bushing Since thermal stress in the joint can be suppressed to a low level, the strength of the joint can be increased.

Furthermore, according to the fourth aspect of the present invention, an insertion hole for the core wire and a connection hole for connecting the core wire and the sensor connection wire are provided concentrically inside the metal bushing, and the insertion hole is provided in the metal bushing. The core wire of the sheath wire is introduced into the connection hole, the end of which is welded once inside the connection hole, and then the sensor connection wire is inserted into the connection hole to connect the core wire and the sensor connection wire. Even if the core wire is made thinner, the core wire and the sensor connection wire can be reliably connected within the connection hole, so that the outer diameter of the sheath wire can be made thinner, and the sheath wire wiring work can be easily performed.

According to the invention set forth in claim 5 of the present invention, the sensor connection wire is formed of a metal with high rigidity, and the portion protruding to the outside of the metal bushing is formed in a plate shape. It is possible to increase the strength of the sensor connection wire protruding to the outside of the sensor, and there is an effect that the sensor wire can be easily connected to the plate-shaped portion by welding.

Further, according to the invention as set forth in claim 6 of the present invention, the mesh metal wire is buried inside the electrically insulating tube made of ceramics, and the brittle nature of the ceramics is reinforced with the mesh metal wire, so that the electrical insulation This has the effect of further increasing the strength of the tube against external forces.

[Brief explanation of drawings]

The first part is a longitudinal cross-sectional view showing the end of a sheath wire and an embodiment of the electrically insulated terminal structure of the present invention, Fig. 2 is a longitudinal cross-sectional view showing another embodiment of the present invention, and Fig. FIG. 4 is a perspective view of the sensor connection wire used in the embodiment of FIG. 3, and FIG. 5 is a longitudinal sectional view showing another embodiment of the present invention. 6 is a side view showing an example of a high-temperature shielded wire, and FIG. 7 is a longitudinal sectional view showing a part of the sheathed wire and a conventional electrically insulated terminal structure. 1-...Sheath wire, 2...Metal clad tube of sheath wire, 3...
・・High-temperature/electrical insulation material, 4. Concentric wire, 15. Electrical insulation tube made of ceramics, ]6.1.7.・Step part provided at the end of electrical insulation tube,】 8. Metal Pipe, 19...Metal bushing, 20.21...Brazing part, 22...Welding part, 23...Insertion hole for core wire, 24...Sensor connection wire,
25 Welding part, 26, 27・Tapered surface provided at the end of electrical insulation pipe, 28, 29... Brazing part, 30・
・Sensor connection line, 31. ．． 32. 1st sensor connection line.
Second part, 33... connection hole, 34, 35... welded part, 36 - mesh metal wire. Agent Patent attorney Masami Akimoto] 5 (Low temperature side) Fig. 5 Funeral diagram] 5 things Rokkusaka slope I) 36° Kiriaki all J class rod diagram

Claims (1)

[Claims] 1. A sheath wire is constructed by inserting a metal core wire that transmits electrical signals into a metal clad tube, and a connecting portion between the core wire of the sheath wire and a connected object such as a sensor. In the high-temperature shielded wire provided with an electrically insulating terminal, the electrically insulating terminal is connected to an electrically insulating tube made of ceramic, a metal tube fitted inside one end of the electrically insulating tube, and an insertion hole for a core wire. and a metal bush fitted inside the other end of the electrically insulating tube, the metal tube is brazed to the electrically insulating tube, and the metal sheathed tube of the sheath wire is placed inside the metal tube. The ends are fitted and welded, the metal bush is brazed to an electrically insulating tube, the core wire of the sheath wire is inserted into the metal bush, and the core wire and the object to be connected are connected at the outer end surface of the metal bush. An electrically insulated terminal structure for high-temperature shielded wire, characterized by welding and sealing the insertion hole for the core wire. 2. The electrically insulating terminal structure for a high-temperature shielded wire according to claim 1, wherein a stepped portion is provided at the brazed portion of the metal tube and the metal bush in the electrically insulating tube. 3. The electrically insulating terminal structure for a high-temperature shielded wire according to claim 1, wherein a tapered surface is formed in the brazed portion of the metal tube and the metal bush in the electrically insulating tube. 4. A core wire insertion hole and a connection hole for connecting the core wire and the sensor connection wire are provided concentrically inside the metal bush, and the core wire of the sheath wire is introduced into the connection hole through the insertion hole and connected. 2. The electrically insulated terminal structure for a high-temperature shielded wire according to claim 1, wherein the core wire and the sensor connection wire are connected by welding in the hole and by inserting a sensor connection wire into the connection hole. 5. The electric high temperature shielded wire according to claim 4, wherein the sensor connection wire is made of a metal with high rigidity, and a portion of the sensor connection wire that protrudes outside the metal bush is formed into a plate shape. Insulated terminal structure. 6. The electrically insulating terminal structure for a high temperature shielded wire according to claim 1, wherein a mesh metal wire is embedded inside the electrically insulating tube.