JP5887125B2 - thermocouple - Google Patents

Description

  The present invention relates to a thermocouple suitable for use in a corrosive environment under conditions that receive external forces such as shearing and bending.

  The thermocouple stores the strand (thermocouple strand) in a metal sheath such as stainless steel or Inconel, and fills the sheath with an insulating material having heat resistance such as magnesium oxide, and further includes the sheath. In order to protect, the thing of the structure which covered the protective tube which covers this sheath on the outer side of this sheath is used widely.

  A thermocouple of the type provided with a metal protective tube as the material of the protective tube described above will corrode the metal protective tube when used in an environment in contact with a corrosive substance such as a molten salt. Cracks or punctures occur, and corrosive substances enter from the site. As a result, the sheath comes into contact with the corrosive substance and is corroded, and eventually the strand of the thermocouple is damaged.

  For this reason, a thermocouple used in contact with a highly corrosive substance has a magnetic protection tube (porcelain protection tube) outside the sheath containing the same wire as described above, for example, as defined in JIS R1401. A type in which a magnetic protective tube is provided so as to cover the outside of the sheath is generally used (see, for example, Patent Document 1).

  By the way, an apparatus used at a high temperature, for example, an ash melting furnace, has a refractory layer provided on the inner surface of the furnace body (furnace shell). Accompanied by erosion. Therefore, during the operation of the ash melting furnace, the temperature of the refractory layer is periodically measured to estimate the degree of erosion of the refractory layer and to determine the maintenance timing. Yes.

  The refractory layer provided on the inner surface of the furnace body of the ash melting furnace is composed of a refractory block in which the molten salt or gasified salt generated in the furnace constitutes the refractory layer. Since the refractory layer passes through the joint or the refractory block itself, the refractory layer becomes an environment where a highly corrosive substance such as the molten salt exists.

  Therefore, when measuring the temperature of the refractory layer in the ash melting furnace, a thermocouple of the type provided with the magnetic protective tube in the opening (through hole) provided in the furnace body of the ash melting furnace, Installation is performed such that the tip of the thermocouple is inserted into a hole provided in advance in the refractory layer inside the furnace body.

  The idea is to divide the protective tube made of alumina ceramic in the length direction, and connect the divided members to each other via a sleeve-like separate member having a two-divided structure, and the divided members to each other. Are different in diameter from each other, and protrusions provided at predetermined intervals in the circumferential direction on the outer peripheral surface of the end portion of the small-diameter division member are predetermined in the circumferential direction on the inner peripheral surface of the end portion of the large-diameter division member. After inserting through the gaps between the protrusions provided at intervals, by relatively rotating the small-diameter dividing member and the large-diameter dividing member, the above-mentioned protrusions are locked together to connect the dividing members. The idea has been proposed in the past (for example, see Patent Document 2).

JP 2001-183240 A JP-A-9-72789

  However, in the ash melting furnace, a volume change occurs between the furnace body and the refractory installed inside the furnace body due to a temperature difference between cold and heat and a temperature change between heat.

  When the volume change between the furnace body and the refractory layer occurs as described above, the relative position may change between the furnace body and the refractory layer due to the joint opening / closing state of the refractory layer and the volume change difference. In addition, when a plurality of refractory layers are provided, the relative positions of the refractory layers may change depending on the opening / closing state of the joints or the volume change difference.

  When the relative position changes, the hole into which the thermocouple is inserted into the refractory also shifts at the boundary, and the thermocouple comes in contact with the thermocouple, causing the thermocouple to shear or bend in the shearing direction. Will receive.

  However, since the magnetic protective tube is a brittle material made of porcelain made of a continuous tube in the longitudinal direction, partial distortion and bending are hardly allowed. Therefore, the furnace in the ash melting furnace When the external force resulting from the change in the relative position between the body and the refractory or the change in the relative position between the refractory layers is received, the magnetic protective tube may be broken or damaged.

  When damage such as cracking or chipping occurs in the magnetic protective tube, corrosive materials such as molten salt present in the refractory layer that is in the corrosive environment can be easily transferred from the damaged portion to the inside of the magnetic protective tube. Since it penetrates, there is a problem that the corrosive substance comes into contact with the sheath in the magnetic protective tube, and the sheath and the strand are damaged by the corrosion and temperature measurement cannot be continued.

  In addition, among the methods shown in Patent Document 2, in the method of connecting the divided members of the protective tube through another member for connecting the sleeve-like structure having a two-part structure, the length of the thermocouple temperature measuring device to be joined is long. The thickness can be easily adjusted, and the protective tube can be used as necessary. Furthermore, it is possible to prevent cracking due to thermal shock. Since a certain ceramic does not have a deformability and is damaged even by a slight distortion or bending due to an external force, the same problem as in the case of using the continuous magnetic protective tube cannot be solved.

  In addition, the method of connecting the divided members having different diameters disclosed in Patent Document 2 cannot solve the problem of breakage due to external force as described above.

  Therefore, the present invention seeks to provide a thermocouple that can maintain the function of preventing contact between a corrosive substance and a sheath by a magnetic tube even when subjected to an external force due to a change or deformation of the relative position of a temperature measurement object. To do.

In order to solve the above-mentioned problems, the present invention corresponds to claim 1 and includes a distal end portion of the sheath on the outer side of a metal sheath containing a strand and filled with a heat-resistant insulating material. The distal end magnetic tube member to be fixed by being covered and the distal end magnetic tube member are divided, and are arranged on the outer periphery near the proximal end of the sheath, and the joint magnetic tube member disposed on the outer periphery of the intermediate portion of the sheath. And a split-type magnetic protective tube comprising: an elastic member for urging the joint magnetic tube member in the direction of the distal magnetic tube member fixed to the distal end portion of the sheath by a restoring force from an elastically deformed state It is set as the structure which provided.

Further, in the above configuration, the split type magnetic protection tube is configured by arranging a plurality of joint magnetic tube members in the outer circumference of the intermediate portion of the sheath in the longitudinal direction of the sheath, and each of the joint magnetic tube members has an axial center. a configuration in which the outer diameter direction destination end side is smaller than the inner diameter in the axial direction base end side, in splicing the magnetic tube members to each other to be disposed adjacent to the longitudinal direction of the sheath in the split-magnetic protective tube, one splicing magnetic the above end in the axial direction of the pipe member, a structure that is to be plugged into a base end portion in the axial direction of the other joint magnetic tube member.

Similarly, in the above configuration, the split magnetic protection tube is configured by arranging a plurality of joint magnetic tube members on the outer periphery of the intermediate portion of the sheath in the longitudinal direction of the sheath, and each joint magnetic tube member is connected to the shaft. the center direction away end face provided with a spherical convex portion, as made comprises a spherical recess configured in the axial direction base end surface, splicing magnetic tube disposed adjacent to the longitudinal direction of the sheath in the split-magnetic protective tube The members are configured such that the spherical convex portion and the spherical concave portion can be fitted to each other.

According to the thermocouple of the present invention, the following excellent effects are exhibited.
(1) A tip magnetic tube member that covers and fixes the distal end portion of the sheath on the outside of a metal sheath that stores an element wire and is filled with an insulating material having heat resistance, and the tip magnetic tube member And a joint magnetic tube member disposed on the outer periphery of the intermediate portion of the sheath, and a joint magnetic tube member disposed on the outer periphery near the proximal end of the sheath and restoring the elastic deformation state to the sheath magnetic tube member. Since the split type magnetic protective tube is provided with an elastic member for urging in the direction of the tip magnetic tube member fixed to the tip of the tip, the deformation or distortion of the temperature measurement object, etc. When an external force acts on the split type magnetic protective tube due to the above, the tip magnetic tube member and each joint magnetic tube member are cracked or chipped by giving the entire deformability by relative displacement between the divided protective tubes. May cause damage It can be prevented. At this time, since the sheath is made of metal, it has deformability and is not damaged.
(2) Even if the joint magnetic tube member is displaced as described above, each joint magnetic tube member is biased by the elastic member in the direction of the tip magnetic tube member. The contact state can be maintained while suppressing the generation of a gap between the magnetic tube members and between the adjacent jointed magnetic tube members. Therefore, when used in a corrosive environment, prevention of contact between the corrosive substance and the sheath can be maintained for a long time.
(3) split the magnetic protective tube, a plurality of splicing magnetic tube member and configured comprising arrayed in the longitudinal direction of the sheath to the outer periphery of the intermediate portion of the sheath, and the respective joint magnetic tube member, axially destination end a configuration in which the outer diameter side is smaller than the inner diameter in the axial direction base end side, splicing magnetic tube members to each other to be disposed adjacent to the longitudinal direction of the sheath in the split-magnetic protective tube of one joint magnetic tube member by-edge portion of the axial direction, a structure in which to be able to plug into a base end portion in the axial direction of the other joint magnetic tube member, in addition to the effect of (1) (2), By following the displacement while maintaining the state where the jointed magnetic tube members are inserted, the contact prevention between the corrosive substance and the sheath can be more effectively maintained, and the effect of the contact prevention can be further ensured. can do.
(4) a split magnetic protective tube, a plurality of splicing magnetic tube member and configured comprising arrayed in the longitudinal direction of the sheath to the outer periphery of the intermediate portion of the sheath, and the respective joint magnetic tube member, axially destination end face As a configuration comprising a spherical convex portion and a spherical concave portion on the base end surface in the axial direction, the joint magnetic tube members arranged adjacent to each other in the longitudinal direction of the sheath in the split magnetic protective tube, In addition to the effects (1) and (2) above, the change in the contact area and the contact state due to displacement is reduced by adopting a configuration in which the spherical convex portion and the spherical concave portion can be fitted. In addition, the effect of preventing contact between the corrosive substance and the sheath can be further ensured.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows an embodiment of a thermocouple of the present invention, where (a) is a partially cut schematic side view, and (b) is a cut side view showing an enlarged base end portion of a split magnetic protective tube. It shows an example of the state in which the split type magnetic protective tube is displaced by the relative displacement between the layers provided inside the furnace body as the temperature measurement object. (A) shows relative displacement between the refractory layers inside the furnace. (B) is a figure which each shows a state when the board layer and refractory layer of a furnace outer side are displaced relatively. The other form of implementation of this invention is shown, (a) is a partial cutting schematic side view, (b) is a schematic diagram which shows the displacement state of a division | segmentation type magnetic protective tube. FIG. 5 shows still another embodiment of the present invention, in which (a) is a partially cut schematic side view, and (b) is a schematic view showing a displacement state of a split magnetic protective tube.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  1 (a) and 1 (b) show an embodiment of the thermocouple of the present invention.

  That is, the thermocouple of the present invention, as indicated by reference numeral 1 in FIGS. 1 (a) and 1 (b), stores an unillustrated strand and fills the outside of a sheath 2 filled with a heat-resistant insulating material, The split magnetic protective tube 3 is provided.

  The split-type magnetic protective tube 3 includes a distal end magnetic tube member 4 that covers and fixes the distal end portion of the sheath 2, a joint magnetic tube member 5 that is disposed on the outer periphery of the intermediate portion of the sheath 2, and a base of the sheath 2. The distal end of the sheath 2 is fixed to the distal end portion of the sheath 2 by a restoring force from the elastic deformation state of the elastic member 6. The configuration is such that the magnetic tube member 4 can be urged in the direction.

  More specifically, the sheath 2 is connected to a terminal head (terminal box) 7 including a terminal (not shown) for connecting a wire (not shown) on the base end side.

  A cylindrical protective neck 8 is disposed concentrically with the sheath 2 on the outer periphery of the proximal end portion of the sheath 2. The protective neck 8 is fixed to the terminal head 7 at the base end that is the end facing the terminal head 7. Further, the protective neck 8 is made of metal such as stainless steel or aluminum alloy. A flange 9 for use in installing the thermocouple 1 of the present invention is attached to the outer periphery of the intermediate portion in the axial direction of the protective neck 8.

  A cylindrical magnetic tube 10 having an outer diameter smaller than the outer diameter of the protective neck 8 is provided on the outer periphery near the base end of the sheath 2 protruding from the distal end portion of the protective neck 8. They are arranged concentrically. The magnetic tube 10 has a base end portion which is an end portion facing the protective neck 8 attached to a distal end portion of the protective neck 8 via a fixing means (not shown) such as heat-resistant cement.

  On the outer periphery of the magnetic tube 10, two washer-shaped (ring-shaped) stoppers 11a and 11b having an inner diameter slightly larger than the outer diameter of the magnetic tube 10 are loosely fitted, and the two stoppers As the elastic member 6, for example, a coil spring 6 (same reference numeral as that of the elastic member 6 is attached for convenience) is disposed between the magnetic members 10 as the elastic member 6 between 11a and 11b.

  The free length of the coil spring 6 is set to be longer by a predetermined dimension than the dimension obtained by subtracting the thickness dimension of the two stoppers 11a and 11b from the length dimension of the magnetic tube 10 in the axial direction. Has been. Thereby, the coil spring 6 is in a state in which one stopper 11 a disposed on the proximal end side of the magnetic tube 10 is in contact with the distal end surface of the protective neck 8, and the other stopper 11 b is in the distal end portion of the magnetic tube 10. When the stoppers 11a and 11b are arranged at the outer peripheral position, they are elastically deformed in the contraction direction between the stoppers 11a and 11b.

  The distal magnetic tube member 4 has a hollow cylindrical shape having an inner diameter slightly larger than the outer diameter of the sheath 2 and is configured such that one end side in the axial direction which is the distal end side is closed. Further, the distal magnetic tube member 4 is covered with the distal end portion of the sheath 2 and fixed to the distal end portion of the sheath 2 via a heat resistant cement 12 as a fixing means.

  The length dimension of the joint magnetic tube member 5 in the axial direction is arranged near the proximal end portion of the distal magnetic tube member 4 fixed to the distal end portion of the sheath 2 and the proximal end of the sheath 2. What is necessary is just to set the distance dimension L between the front-end | tip parts of the magnetic pipe | tube 10 so that it may respond | correspond to the dimension equally divided into plurality. Therefore, the joint magnetic tube member 5 may be attached to the outer periphery of the intermediate portion of the sheath 2 in a number array corresponding to the predetermined number of divisions.

  The material of each of the magnetic tube members 4 and 5 and the material of the magnetic tube 10 are assumed to be the same porcelain as the material used in the conventional magnetic protective tube.

  When the split magnetic protective tube 3 is attached to the outside of the sheath 2, the sheath 2 is provided on the outer periphery of the magnetic tube 10 fixed to the terminal head 7 via the protective neck 8 and the sheath 2. After the stopper 11a, the coil spring 6, the stopper 11b, and the predetermined number of joint magnetic tube members 5 are fitted in order from the distal end side, the joint magnetic tube member 5 is disposed closest to the distal end of the sheath 2. The coil spring 6 is contracted by pressing the object toward the proximal end of the sheath 2, and the distal magnetic tube member 4 is moved through the heat-resistant cement 12 while maintaining the state of the coil spring 6. It is sufficient to fix to. Thus, the distal end of each joint magnetic tube member 5 fitted to the outer periphery of the sheath 2 is fixed to the distal end portion of the sheath 2 by the restoring force of the coil spring 6 elastically deformed in the contraction direction. The magnetic tube member 4 is biased in the direction.

  Between the inner peripheral surface of each joint magnetic tube member 5 attached to the outer periphery of the intermediate portion of the sheath 2 and the outer peripheral surface of the sheath 2 positioned on the inner side, heat resistance such as magnesium oxide is provided. Insulating material (not shown) is filled. Further, when there is a gap between the tip magnetic tube member 4 and the sheath 2 positioned inside, the gap is filled with the insulating material (not shown). Further, the insulating material (not shown) is also filled between the magnetic tube 10 and the sheath 2 positioned inside thereof.

  In addition, Fig.1 (a) has shown an example of the attachment method of the thermocouple of this invention. As shown in FIG. 1A, the thermocouple 1 of the present invention is a thermocouple mounting seat provided on an outer casing of a furnace body 14 which is a double casing of an ash melting furnace which is the temperature measurement object 13. 18, when the flange 9 is attached, only the portion of the sheath 2 covered by the tip magnetic tube member 4 and each joint magnetic tube member 5 is disposed in the inner casing of the furnace body 14. The total length of the thermocouple 1 of the present invention, the length dimension of the protective neck 8, and the mounting position of the flange 9 with respect to the protective neck 8 are set. As a result, in the thermocouple 1 of the present invention, the coil spring 6 as an elastic member provided to urge each joint magnetic tube member 5 toward the tip magnetic tube member 4 is provided outside the furnace body 14. It is set as the structure arrange | positioned to.

  In the furnace body 14, a board layer 15 such as ceramic fiber, a refractory layer 16b as a second layer, and a refractory layer 16b as a first layer are laminated in order from the inside of the double casing to the inside of the furnace. ing. Reference numeral 17 denotes a wool material such as ceramic fiber filled in an annular space between the board layer 15 such as ceramic fiber and the joint magnetic tube member 5.

  As shown in FIG. 1A, the thermocouple 1 of the present invention configured as described above is installed and used in a furnace body 14 of an ash melting furnace which is a temperature measurement object 13. At this time, when the thermocouple 1 of the present invention is inserted up to the boundary portion between the refractory layers 16a and 16b, the tip portion of the tip magnetic tube member 4 is merely brought into contact with the surface of the refractory layer 16b. Like that.

  In this state, for example, as shown in FIG. 2A, a change in the relative position of the plurality of refractory layers 16a and 16b provided inside the furnace body 14 causes the refractory layer 16b to move to an arrow A, for example. 2b or when the board layer 15 such as ceramic fiber of the furnace body 14 and the refractory layers 16a and 16b are deformed, for example, the refractory layer 16a is displaced in the direction of arrow B as shown in FIG. Due to such a situation, in the portion corresponding to the boundary between the refractory layer 16b and the board layer 15 and the refractory layer 16a in the split magnetic protective tube 3 of the thermocouple 1 of the present invention, When an external force is applied, the thermocouple 1 of the present invention is such that the split members constituting the joint magnetic tube member 5 disposed at the location where the external force is received in the split magnetic protective tube 3 are relatively displaced. , The above split magnetic It is possible to prevent damage to the cracking and chipping of the tip magnetic tube member 4 and the joint magnetic tube member 5 to form a tube 3. Even if some of the joint magnetic tube members 5 forming the split magnetic protection tube 3 are displaced as described above, all of the joint magnetic tube members 5 are connected to the tip magnetic tube member by the coil spring 6. 4, the gap between the distal magnetic tube member 4 adjacent to the longitudinal direction of the sheath 2 and the joint magnetic tube member 5, and between the adjacent joint magnetic tube members 5. It is possible to suppress the occurrence of the gap.

Further, the gap between the magnetic tube members 4 and 5 and the inner sheath 2 is filled with a heat-resistant insulating material such as magnesium oxide and exists in the refractory layers 16a and 16b of the ash melting furnace. It can be a resistance when a corrosive substance such as a molten salt enters through a seam.

  As described above, the thermocouple 1 of the present invention can prevent the split magnetic protective tube 3 from being damaged even if it receives an external force due to deformation or distortion of the temperature measurement object 13, and has a corrosive environment. When used in the above, the prevention of contact between the corrosive substance and the sheath 2 can be maintained for a long time.

  Furthermore, the tip magnetic tube member 4 constituting the split magnetic protection tube 3 has a cylindrical shape with one end side in the axial direction closed, and each joint magnetic tube member 5 has a cylindrical shape. However, it is not necessary to have a complicated structure in which protrusions are provided on the inner peripheral surface or the outer peripheral surface. Therefore, the thermocouple 1 of the present invention can reduce labor and cost required for manufacturing the split magnetic protective tube 3.

  Next, FIGS. 3A and 3B show another embodiment of the present invention. In the same configuration as shown in FIGS. 1A and 1B, the split magnetic protection tube 3 is simply constructed. In place of the configuration including the cylindrical joint magnetic tube member 5, the split type magnetic protective tube 3 has an outer diameter at one end side in the axial direction which is the distal end side and the other end portion in the axial direction which is the proximal end side. A hollow cylindrical joint magnetic tube member 5a having a tapered peripheral wall smaller than the inner diameter is provided.

  Thereby, when a plurality of the joint magnetic tube members 5a are arranged on the outer periphery of the intermediate portion of the sheath 2 along the longitudinal direction of the sheath 2, the joint magnetic tube members 5a are arranged adjacent to each other. The one end portion in the axial direction of the joint magnetic tube member 5a can be inserted into the inside of the other end portion in the axial center direction of another joint magnetic tube member 5a adjacent to the distal end side of the sheath 2.

  Further, the distal end magnetic tube member 4a of the split type magnetic protective tube 3 has an inner diameter on the other end side in the axial direction which is the base end side, than an outer diameter on the one end side in the axial direction of the joint magnetic tube member 5a. The configuration is large. As a result, of the joint magnetic tube members 5a disposed on the outer periphery of the intermediate portion of the sheath 2, one end portion in the axial direction of the joint magnetic tube member 5a disposed closest to the distal end of the sheath 2 is disposed at the distal end magnetic field. The tube member 4a can be inserted inside the other axial end portion.

  In the present embodiment, the axial dimension of each joint magnetic tube member 5a is set in the axial direction dimension of the joint magnetic tube member 5 described in the embodiment of FIGS. 1 (a) and 1 (b). As compared with the dimension determined by the above, one axial end portion of the joint magnetic tube member 5a in the present embodiment is inserted into another joint magnetic tube member 5a or the other axial end portion of the tip magnetic tube member 4a. What is necessary is just to set so that it may become long.

  Other configurations are the same as those shown in FIGS. 1A and 1B, and the same components are denoted by the same reference numerals.

  According to the thermocouple 1 of the present embodiment, for example, as shown in FIGS. 2 (a) and 2 (b), the change in the relative position between the refractory layers 16a and 16b of the furnace body 14 which is the temperature measurement object 13, When the relative position of the board layer 15 and the refractory layer 16a changes, the split magnetic protective tube 3 can be displaced as shown in FIG. 3B, so that the implementation of FIGS. The same effect as the form can be obtained. In addition to this, in the split magnetic protection tube 3, the joints between the joint magnetic tube members 5a disposed in the longitudinal direction of the sheath 2 on the outer periphery of the sheath 2, and the joint magnetic tube member 5a and the tip At the joint with the magnetic tube member 4a, the peripheral walls are arranged so as to overlap each other, so that it is possible to more reliably prevent the corrosive substance from entering the joint.

  Therefore, the thermocouple 1 of the present embodiment can prevent the split magnetic protective tube 3 from being damaged even if it receives an external force due to deformation or distortion of the temperature measurement object 13, and further corrosive. The effect of preventing contact between the substance and the sheath 2 can be made more reliable.

  4 (a) and 4 (b) show still another embodiment of the present invention. In the same configuration as shown in FIGS. 1 (a) and 1 (b), the joint magnetism of the split magnetic protective tube 3 is shown. Instead of the configuration in which the tube member 5 has a simple cylindrical shape, the jointed magnetic tube member 5b includes a spherical convex portion 19 on one axial end surface of the cylindrical outer shape, and the other axial end surface. The spherical concave portion 20 is provided.

  Thereby, when a plurality of the joint magnetic tube members 5b are arranged on the outer periphery of the intermediate portion of the sheath 2 along the longitudinal direction of the sheath 2, the joint magnetic tube members 5b are arranged adjacent to each other. The spherical convex portion 19 on one end side in the axial direction of the joint magnetic tube member 5b is fitted into the spherical concave portion 20 on the other end side in the axial direction of another joint magnetic tube member 5b adjacent to the distal end side of the sheath 2. Can be combined.

  Further, the distal end magnetic tube member 4b of the split magnetic protective tube 3 is similar to the spherical concave portion 20 on the other axial end side of the joint magnetic tube member 5b on the other axial end surface on the proximal end side. The spherical concave portion 20a is provided. As a result, of the joint magnetic tube members 5b arranged on the outer periphery of the intermediate portion of the sheath 2, the spherical convex portion on one end side in the axial direction of the joint magnetic tube member 5b arranged closest to the distal end of the sheath 2 19 can be fitted into the spherical recess 20a on the other end side in the axial direction of the tip magnetic tube member 4b.

  In the present embodiment, the axial center dimension of each joint magnetic tube member 5b is the method of setting the axial center dimension of the joint magnetic tube member 5 described in the embodiment of FIGS. 1 (a) and 1 (b). Compared with the dimension determined by the above, the length of the protruding portion of the spherical convex portion 19 on one end side in the axial center direction of the joint magnetic tube member 5b in the present embodiment may be set longer.

  Other configurations are the same as those shown in FIGS. 1A and 1B, and the same components are denoted by the same reference numerals.

  According to the thermocouple 1 of the present embodiment, each joint magnetic tube member 5b of the split-type magnetic protective tube 3 can be displaced as shown in FIG. 4B, so that the implementation of FIGS. 1A and 1B is performed. The same effect as that of the embodiment can be obtained. In addition, in the split magnetic protection tube 3, the joints between the joint magnetic tube members 5b arranged on the outer periphery of the sheath 2 in the longitudinal direction of the sheath 2, and the joint magnetic tube member 5b and the tip At the joint with the magnetic tube member 4b, since the fitting structure of the spherical convex portion 19 and the spherical concave portions 20 and 20a is formed, the external force acts on the split magnetic protective tube 3, Even if a slight angle change occurs at each joint, the change in the contact area or contact state between adjacent magnetic tube members 5b or between 5b and 4b is small, and there is no possibility that a gap will be generated. For this reason, the thermocouple 1 of the present embodiment can more reliably prevent corrosive substances from entering the joints.

  Therefore, the thermocouple 1 of the present embodiment can prevent the split magnetic protective tube 3 from being damaged even if it receives an external force due to deformation or distortion of the temperature measurement object 13, and further corrosive. The effect of preventing contact between the substance and the sheath 2 can be made more reliable.

  The present invention is not limited only to the above-described embodiment, and each of the above-described embodiments has shown the configuration in which the coil spring 6 is provided as the elastic member 6. , 5a, 5b are arranged on the outer periphery closer to the proximal end of the sheath 2 and are loosely fitted to the outer periphery of the intermediate portion of the sheath 2 by the restoring force from the elastically deformed state. If it is possible to bias 5, 5a, 5b in the direction of the distal magnetic tube members 4, 4a, 4b fixed to the distal end of the sheath 2, a spring other than the coil spring 6 such as a disc spring It is good also as a structure provided with elastic members 6 other than the coil spring 6, such as a member and also rubber | gum.

  The joint magnetic tube member 5a in the embodiment of FIGS. 3A and 3B has a joint magnetic tube that is adjacently disposed so that the outer diameter on one end side in the axial direction is smaller than the inner diameter on the other end side in the axial direction. As long as the members 5a can be inserted into the end of one joint magnetic tube member 5a on the one axial end side in the other axial end of the other joint magnetic tube member 5a. The shapes of the outer peripheral wall and the inner peripheral wall of the joint magnetic tube member 5a may be shapes other than those illustrated.

  1 (a) (b), FIG. 2 (a) (b), and FIG. 3 (a) (b) are the same as the embodiment of FIG. 4 (a) (b). Similarly to the above, the joint magnetic tube members 5 and 5 a arranged near the tip of the sheath 2 may be fixed to the sheath 2 via the heat-resistant cement 12. 4 (a) and 4 (b), the heat-resistant cement 12 is composed of a tip magnetic tube as in FIGS. 1 (a) and (b), FIGS. 2 (a) and (b), and FIGS. 3 (a) and 3 (b). You may make it interpose only between the inner side of the member 4b, and the sheath 2. FIG.

  Furthermore, in each of the embodiments, the joint magnetic tube member 5, which is disposed closer to the distal end of the sheath 2, according to the position where the external force in the split magnetic protective tube 3 of the thermocouple 1 of the present invention is assumed to act. The number fixed to the sheath 2 of 5a, 5b may be changed freely.

  As the fixing means for fixing the tip magnetic tube members 4, 4 a, 4 b and the joint magnetic tube members 5, 5 a, 5 b to the sheath 2 as necessary as described above, the heat-resistant cement 12 is exemplified. You may employ | adopt the fixing means which has the arbitrary heat resistance currently used for fixation of members with the conventional thermocouple.

  In the embodiment shown in FIG. 3A, the tip magnetic tube member 4a is shown as having a tapered shape with a tapered outer diameter, but the tip magnetic tube member 4a is the same in the axial direction. It is good also as a shape used as an outer diameter dimension.

  The thermocouple 1 of the present invention may be applied to temperature measurement of any temperature measurement object other than the ash melting furnace.

  Of course, various changes can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Thermocouple 2 Sheath 3 Split-type magnetic protective tube 4, 4a, 4b Tip magnetic tube member 5, 5a, 5b Joint magnetic tube member 6 Coil spring (elastic member)
19 Spherical convex 20 Spherical concave

Claims (3)

A tip magnetic tube member that covers and fixes the distal end portion of the sheath on the outside of a metal sheath that stores a strand and is filled with an insulating material having heat resistance, and the tip magnetic tube member are divided. have been, and splicing magnetic tube member disposed on the outer periphery of the middle portion of the sheath, the distal end of the sheath to the splicing magnetic tube member by the restoring force of the arrangement to and elastically deformed state on the outer periphery of the base end side of the above sheath A thermocouple comprising a split magnetic protective tube provided with an elastic member for urging in the direction of the tip magnetic tube member fixed to the tip. The split magnetic protective tube, a plurality of splicing magnetic tube member on the outer periphery of the middle portion of the sheath is configured comprising arrayed in the longitudinal direction of the sheath, and the respective joint magnetic tube member, axially destination end a configuration in which the outer diameter side is smaller than the inner diameter in the axial direction base end side, in splicing the magnetic tube members to each other to be disposed adjacent to the longitudinal direction of the sheath in the split-magnetic protective tube, on one splicing magnetic tube member the previous end of the axial direction, thermocouple according to claim 1, wherein the to be plugged to the base end portion in the axial direction of the other joint magnetic tube member. The split magnetic protective tube, a plurality of splicing magnetic tube member on the outer periphery of the middle portion of the sheath is configured comprising arrayed in the longitudinal direction of the sheath, and the respective joint magnetic tube member, axially destination end face As a configuration comprising a spherical convex portion and a spherical concave portion on the base end surface in the axial direction, the joint magnetic tube members arranged adjacent to each other in the longitudinal direction of the sheath in the split magnetic protective tube, The thermocouple according to claim 1, wherein the spherical convex portion and the spherical concave portion can be fitted.

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