WO2024032343A1

WO2024032343A1 - Thermal expansion compensation fiber optic insulator and method for using same

Info

Publication number: WO2024032343A1
Application number: PCT/CN2023/108350
Authority: WO
Inventors: 张广泰; 王强; 刘海彬; 李钊; 严伟; 吴继平; 李磊; 刘亮; 达建朴; 郝兆荣; 杨洪涛; 蒋斌; 张晓霞; 张良
Original assignee: 常州博瑞电力自动化设备有限公司; 南京南瑞继保工程技术有限公司; 南京南瑞继保电气有限公司
Priority date: 2022-08-10
Filing date: 2023-07-20
Publication date: 2024-02-15
Also published as: CN115359976B; CN115359976A

Abstract

Disclosed in the present invention are a thermal expansion compensation fiber optic insulator and a method for using same. The thermal expansion compensation fiber optic insulator comprises an insulating assembly; the insulating assembly comprises a hanging flange, an expansion joint, pressing members, a fixing flange, and an insulator; one end of the expansion joint is connected to the hanging flange, and the other end of the expansion joint is connected to the fixing flange; the pressing members are mounted on the expansion joint; and the insulator matches the fixing flange. According to the device, by means of cooperation between the expansion joint and the pressing members, complete filling of a glue solution is achieved in a core body of the fiber optic insulator, thereby avoiding the problems of glue solution leakage, fiber optic pressing and the like, and improving the insulating property.

Description

A thermal expansion compensation optical fiber insulator and its use method

Technical field

The invention relates to the technical field of high-voltage power systems, in particular to a thermal expansion compensation optical fiber insulator and a method of using the same.

Background technique

Optical fiber composite insulators are an important part of transformer equipment. They are used to collect, transmit and monitor information under high voltage, and facilitate the safe operation and maintenance of transformer equipment. Optical fiber insulators are mainly composed of hollow epoxy core rods, silicone sheds, fixed flanges, optical fibers, and liquid insulating media. The transformers are installed outdoors, and the temperature changes greatly. The liquid insulating media inside the insulator is affected by thermal expansion and contraction, so Optical fiber insulators are required to meet the volume change requirements of liquid media.

If the optical fiber insulator adopts the opening method, it is easy to cause leakage of liquid medium. If the fully enclosed structure is used, it is easy to generate internal pressure, squeezing the internal optical fiber, causing damage to the optical fiber or distortion of optical signal transmission. If the liquid medium is not satisfied, the insulation level will be reduced, and the field strength of the flange will be reduced. Too high will cause partial discharge and local heat increase, which will damage the insulator and internal optical fiber. In addition, the fixed flange of the optical fiber insulator is usually a metal structure, and the field strength at the flange end is high. Therefore, the existing optical fiber insulator structure can no longer meet the actual requirements. need.

Contents of the invention

The purpose of this section is to outline some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the invention to avoid confusing this section, the description. The purpose of the abstract and title is ambiguous, and such simplification or omission cannot be used to limit the scope of the invention.

In view of the above and/or problems existing in the prior art, the present invention is proposed.

Therefore, the technical problem to be solved by the present invention is to overcome the problems of optical fiber damage or optical signal transmission distortion caused by thermal expansion and contraction of the liquid insulating medium inside the existing insulator, lower insulation level and high field strength of the fixed flange.

In order to solve the above technical problems, the present invention provides the following technical solution: a thermal expansion compensation optical fiber insulator and its use method include an insulating component, which includes a hanging flange, an expansion joint, an extrusion piece, a fixed flange and an insulator. One end of the expansion joint is connected to the hanging flange, and the other end is connected to the fixed flange. The extrusion piece is installed on the expansion joint, and the insulator cooperates with the fixed flange.

As a preferred embodiment of the thermal expansion compensation optical fiber insulator and its use method according to the present invention, Medium: The hanging flange includes a hanging hook and an optical fiber column. The hanging hook is arranged on the upper end of the hanging flange, and the optical fiber column is arranged on the circumferential surface of the hanging flange.

As a preferred solution of the thermal expansion compensation optical fiber insulator and its use method of the present invention, the expansion joint includes an expansion cavity and an optical fiber hole, the expansion cavity is arranged inside the expansion joint, and the optical fiber hole The optical fiber hole is disposed through the upper end of the expansion joint and communicates with the expansion cavity.

As a preferred embodiment of the thermal expansion compensation optical fiber insulator and its use method of the present invention, the expansion joint further includes a cylinder hole, a snap-on bump and an expansion threaded hole, and the cylinder hole is provided on the side of the expansion joint. , the engaging bump is provided at the lower end of the expansion joint, the expansion threaded hole is provided at the upper end of the expansion joint, the cylinder hole communicates with the expansion cavity, and there are multiple cylinder holes.

As a preferred solution of the thermal expansion compensation optical fiber insulator and its use method of the present invention, the hanging flange further includes a cavity and an upper threaded hole, and the cavity and the upper threaded hole are provided in the At the lower end of the hanging flange, there are multiple upper threaded holes, and upper screws pass through the upper threaded holes to connect with the expansion threaded holes;

A lead-out hole is provided on the optical fiber column, and the lead-out hole communicates with the cavity.

As a preferred solution of the thermal expansion compensating optical fiber insulator and its use method of the present invention, the extrusion part includes a piston, a spring and a threaded end cap, the spring is sleeved on the piston, and one end of the piston The threaded end cap is matched with the other end placed in the cylinder hole, and the threaded end cap is threadedly matched with the cylinder hole.

As a preferred solution of the thermal expansion compensation optical fiber insulator and its use method of the present invention, the fixing flange includes a fixing groove and a fixing threaded hole, and the fixing groove and the fixing threaded hole are provided in the fixing method. On the upper end of the blue, there are multiple fixing threaded holes, the engaging convex block is placed in the fixing groove, and the lower screw passes through the fixing threaded hole and is connected to the expansion threaded hole.

As a preferred solution of the thermal expansion compensation optical fiber insulator and its use method of the present invention, the piston includes a piston rod and a sliding column, the sliding column is arranged on the side of the piston rod, and the piston rod is placed on the side of the piston rod. Inside the cylinder hole;

The piston rod is provided with a mounting groove;

A sealing groove is provided on the side of the threaded end cap, and the sliding column is inserted into the sealing groove.

As a preferred embodiment of the thermal expansion compensating optical fiber insulator and its use method of the present invention, a glue injection hole is provided at the lower end of the insulator, and the glue injection hole penetrates the insulator.

As a preferred embodiment of the thermal expansion compensation optical fiber insulator and its use method according to the present invention, Middle: Pass the optical fiber through the glue injection hole and the expansion cavity and lead it out from the optical fiber hole, and push the piston to the deepest position of the cylinder hole;

Inject glue into the glue injection hole at the lower end of the insulator at normal temperature. When the glue is injected into the fiber hole, the fiber hole is sealed through the locking joint;

Continue to inject glue so that the piston moves under the pressure of the glue fluid to the middle of the cylinder hole, and then closes the glue injection hole;

The optical fiber led out from the fiber hole passes through the cavity and out of the outlet hole, and then the upper screw passes through the upper threaded hole and is connected to the expansion threaded hole to fix the hanging flange and expansion joint;

The engaging bump is placed in the fixing groove, and a plurality of lower screws are passed through the fixing threaded hole to connect with the expansion threaded hole to fix the fixing flange and the expansion joint.

Beneficial effects of the present invention: This device, through the cooperation of expansion joints and extrusion parts, enables the fiber insulator core to be completely filled with glue, thereby avoiding problems such as glue leakage or fiber extrusion and improving insulation.

Description of drawings

In order to explain the technical solutions of the embodiments of the present invention more clearly, the drawings needed to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. Those of ordinary skill in the art can also obtain other drawings based on these drawings without exerting any creative effort. in:

Figure 1 is a schematic diagram of the assembly structure of a thermal expansion compensation optical fiber insulator and its use method according to an embodiment of the present invention;

Figure 2 is a schematic diagram of the component connection structure of the thermal expansion compensation optical fiber insulator and its use method according to an embodiment of the present invention;

Figure 3 is a schematic structural diagram of a hanging flange in a thermal expansion compensation optical fiber insulator and a method of using the same according to an embodiment of the present invention;

Figure 4 is a schematic cross-sectional structural view of an expansion joint in a thermal expansion compensation optical fiber insulator and a method of using the same according to an embodiment of the present invention;

Figure 5 is a schematic structural diagram of an extruded part of a thermal expansion compensation optical fiber insulator and a method of using the same according to an embodiment of the present invention;

FIG. 6 is a schematic structural diagram of a fixing flange of a thermal expansion compensation optical fiber insulator and a method of using the same according to an embodiment of the present invention.

Detailed ways

In order to make the above objects, features and advantages of the present invention more obvious and understandable, the following description is given in conjunction with the description. The accompanying drawings illustrate specific embodiments of the present invention in detail.

Many specific details are set forth in the following description to fully understand the present invention. However, the present invention can also be implemented in other ways different from those described here. Those skilled in the art can do so without departing from the connotation of the present invention. Similar generalizations are made, and therefore the present invention is not limited to the specific embodiments disclosed below.

Secondly, the present invention will be described in detail with reference to schematic diagrams. When describing the embodiments of the present invention in detail, for the convenience of explanation, the cross-sectional diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples and should not be limited here. protection scope of the present invention. In addition, the three-dimensional dimensions of length, width and depth should be included in actual production.

Furthermore, "one embodiment" or "an embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. "In one embodiment" appearing in different places in this specification does not all refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

Example 1

Referring to FIGS. 1 to 4 , this embodiment provides a thermal expansion compensation optical fiber insulator and a method of using the same, including an insulation component 100 .

The insulation assembly 100 includes a hanging flange 101, an expansion joint 102, an extrusion piece 103, a fixed flange 104 and an insulator 105. One end of the expansion joint 102 is connected to the hanging flange 101 and the other end is connected to the fixed flange 104. Part 103 is installed on the expansion joint 102, and the insulator 105 cooperates with the fixed flange 104.

A plurality of extruded pieces 103 are provided.

The hanging flange 101 includes a hanging hook 101a and an optical fiber column 101b. The hanging hook 101a is arranged on the upper end of the hanging flange 101, and the optical fiber column 101b is arranged on the circumferential surface of the hanging flange 101.

The hook 101a is provided with a through hole for fixing and connecting.

The expansion joint 102 includes an expansion cavity 102a and a fiber optic hole 102b. The expansion cavity 102a is disposed inside the expansion joint 102. The fiber optic hole 102b is disposed through the upper end of the expansion joint 102. The fiber optic hole 102b communicates with the expansion cavity 102a.

The expansion joint 102 also includes a cylinder hole 102c, an engaging protrusion 102d, and an expansion threaded hole 102e. The cylinder hole 102c is provided on the side of the expansion joint 102, the engaging protrusion 102d is provided on the lower end of the expansion joint 102, and the expansion threaded hole 102e is provided on the expansion joint. At the upper end of 102, the cylinder hole 102c communicates with the expansion chamber 102a, and there are multiple cylinder holes 102c.

Preferably, one cylinder hole 102c is provided on each of the four sides of the expansion joint 102 to better fix the optical fiber.

The hanging flange 101 also includes a cavity 101c and an upper threaded hole 101d. The cavity 101c and the upper threaded hole 101d are provided at the lower end of the hanging flange 101. There are multiple upper threaded holes 101d, and a number of upper screws 106 pass through the upper threads. The hole 101d is threadedly connected to the expansion threaded hole 102e to fix the hanging flange 101 and the expansion joint 102.

A square plate is also provided on the circumferential surface of the hanging flange 101 for hanging the nameplate.

The optical fiber column 101b is provided with a lead-out hole 101b-1. The lead-out hole 101b-1 communicates with the cavity 101c, which facilitates the optical fiber routing to pass through the cavity 101c and out of the lead-out hole 101b-1.

Example 2

Referring to FIGS. 2 to 6 , a second embodiment of the present invention is shown. Based on the previous embodiment, this embodiment provides an implementation of a thermal expansion compensation optical fiber insulator and a method of using the same.

The extrusion piece 103 includes a piston 103a, a spring 103b and a threaded end cap 103c. The spring 103b is sleeved on the piston 103a. The piston 103a cooperates with the threaded end cap 103c. The piston 103a is placed in the cylinder hole 102c. The threaded end cap 103c is in contact with the cylinder hole. 102c thread fit.

The piston 103a includes a piston rod 103a-1 and a sliding rod 103a-2. The sliding rod 103a-2 is arranged on the side of the piston rod 103a-1, and the piston rod 103a-1 is placed in the cylinder hole 102c.

The piston rod 103a-1 is provided with a mounting groove 103a-11, and there are two mounting grooves 103a-11.

Furthermore, the connection method between the piston column 103a-1 and the sliding column 103a-2 can be welding, one-piece molding or threaded connection, preferably threaded connection to facilitate adjustment of the overall length of the piston 103a to better adapt to the use of the device.

A sealing groove 103c-1 is provided on the side of the threaded end cap 103c, and the sliding column 103a-2 is inserted into the sealing groove 103c-1.

The piston 103a and the threaded end cap 103c cooperate in such a way that the sliding column 103a-2 is inserted into the slot in the sealing groove 103c-1. A dust ring is installed in the sealing groove 103c-1. The sliding column 103a-2 can be inserted into the sealing groove 103c-1. Slide within -1.

Guide rings and sealing rings are respectively installed on the two installation grooves 103a-11. The roughness Ra value of the inner wall of the cylinder bore 102c must be less than 0.8 μm to ensure that the piston rod 103a-1 can slide well in the cylinder bore 102c and ensure good of sealing.

The fixing flange 104 includes a fixing groove 104a and a fixing threaded hole 104b, the fixing groove 104a and the fixing threaded hole 104b. The threaded hole 104b is provided through the upper end of the fixing flange 104. There are multiple fixing threaded holes 104b. The engaging projection 102d is placed in the fixing groove 104a. The lower screw 107 passes through the fixing threaded hole 104b and is connected to the expansion threaded hole 102e to fix it. The flange 104 and the expansion joint 102 are fixed.

Further, the fixed flange 104 is made of epoxy material and coated with a protective coating. The insulator 105 and the fixed flange 104 cooperate by heating the fixed flange 104 and then setting it on the core rod of the insulator 105. After cooling, it is The insulator 105 forms an interference fit.

A glue injection hole 105a is provided at the lower end of the insulator 105, and the glue injection hole 105a penetrates the insulator 105.

During assembly, the piston 103a is placed in the cylinder hole 102c, the spring 103b is placed on the sliding column 103a-2, and then the threaded end cover 103c is threaded with the cylinder hole 102c. During this process, the spring 103b contacts the sealing groove 103c-1 and is subjected to Squeezing produces slight deformation.

Then, the engaging bump 102d is placed in the fixing groove 104a, and several lower screws 107 are passed through the fixing threaded hole 104b to connect with the expansion threaded hole 102e to fix the fixing flange 104 and the expansion joint 102, and several upper screws 106 are passed through. Pass through the threaded hole 101d and thread it with the expansion threaded hole 102e to fix the hanging flange 101 and the expansion joint 102.

Example 3

Referring to FIGS. 1 to 6 , a third embodiment of the present invention is shown. Based on the previous two embodiments, this embodiment provides an implementation of a thermal expansion compensation optical fiber insulator and a method of using the same.

When in use, the optical fiber is led out from the fiber hole 102b through the glue injection hole 105a and the expansion cavity 102a, the piston 103a is pushed to the deepest position of the cylinder hole 102c, and the spring 103b and the threaded end cap 103c are installed and fixed.

Glue is injected into the glue injection hole 105a at the lower end of the insulator 105 at normal temperature. The glue injection hole 105a, the fixing groove 104a, the expansion cavity 102a and the fiber optic hole 102b are all connected. When the glue is injected into the fiber hole 102b, the glue is injected into the fiber hole 102b through the locking joint. The fiber hole 102b is sealed.

The insulating medium in this device is glue, and the specific type can be selected according to needs.

Continue to inject glue, so that the piston 103a is moved by the pressure of the glue fluid and moves to the middle position of the cylinder hole 102c, and then the glue injection hole 105a is closed. At this time, the spring 103b is deformed.

The optical fiber extracted from the optical fiber hole 102b passes through the cavity 101c and out of the extraction hole 101b-1, and then the upper screw 106 passes through the upper threaded hole 101d and is connected to the expansion threaded hole 102e to fix the hanging flange 101 and the expansion joint 102.

The engaging bump 102d is placed in the fixing groove 104a, and a plurality of lower screws 107 are passed through the fixing threaded holes. 104b is connected to the expansion threaded hole 102e to fix the fixing flange 104 and the expansion joint 102.

When the external temperature of the device is too high, the internal glue expands when heated and squeezes the piston rod 103a-1, causing it to displace outward in the cylinder hole 102c. The sliding column 103a-2 simultaneously displaces in the sealing groove 103c-1, and the spring 103b When deformed by extrusion, the energy is converted into elastic potential energy to avoid damage to the internal optical fiber and distortion of optical fiber transmission.

When the external temperature of the device decreases, the internal glue shrinks due to cold, and the squeezing force on the piston rod 103a-1 disappears. The spring 103b releases elastic potential energy to push the piston rod 103a-1 and the glue to move inward along the cylinder hole 102c, causing expansion. The glue inside the cavity 102a is always filled to avoid the problem of insulation being reduced due to incomplete filling of the glue.

This device can undergo adaptive changes according to changes in temperature, so that the glue in the expansion cavity 102a is always filled, ensuring the insulation of the device and good communication of optical fibers, and the fixed flange 104 in this device is made of epoxy material , and are coated with a protective coating to avoid the problem that the flange end has a high field strength and is prone to heat, thereby damaging the insulator and internal optical fibers.

It is important to note that the construction and arrangements of the present application shown in various exemplary embodiments are illustrative only. Although only a few embodiments are described in detail in this disclosure, those reviewing this disclosure will readily appreciate that many modifications are possible without materially departing from the novel teachings and advantages of the subject matter described in this application. are possible (e.g. variations in size, scale, structure, shape and proportion of various elements, as well as parameter values (e.g. temperature, pressure, etc.), mounting arrangements, use of materials, colors, orientations, etc.). For example, an element shown as integrally formed may be constructed from multiple parts or elements, the position of elements may be inverted or otherwise altered, and the nature or number or position of discrete elements may be altered or varied. Accordingly, all such modifications are intended to be included within the scope of this invention. The order or sequence of any process or method steps may be changed or reordered according to alternative embodiments. In the claims, any "means-plus-function" clause is intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Other substitutions, modifications, changes and omissions may be made in the design, operation and arrangement of the exemplary embodiments without departing from the scope of the invention. Therefore, the invention is not limited to particular embodiments, but extends to various modifications which still fall within the scope of the appended claims.

Furthermore, in order to provide a concise description of the exemplary embodiments, not all features of an actual implementation may be described (i.e., those features that are not relevant to the best mode presently contemplated for carrying out the invention, or that are not relevant to carrying out the invention) feature).

It is understood that numerous implementation-specific decisions may be made during the development of any actual implementation, as in any engineering or design project. Such a development effort might be complex and time consuming, but would be a routine undertaking of design, manufacture and production without undue experimentation to those of ordinary skill having the benefit of this disclosure .

It should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solution of the present invention can be carried out. Modifications or equivalent substitutions without departing from the spirit and scope of the technical solution of the present invention shall be included in the scope of the claims of the present invention.

Claims

A thermal expansion compensation optical fiber insulator, characterized by: including,

The insulation assembly (100) includes a hanging flange (101), an expansion joint (102), an extrusion piece (103), a fixed flange (104) and an insulator (105). One end of the expansion joint (102) is connected to the The hanging flange (101) is connected and the other end is connected to the fixed flange (104). The extrusion piece (103) is installed on the expansion joint (102). The insulator (105) is connected to the The fixed flange (104) matches.
The thermal expansion compensation optical fiber insulator according to claim 1, characterized in that: the hanging flange (101) includes a hanging hook (101a) and an optical fiber column (101b), and the hanging hook (101a) is arranged on the hanging flange (101). At the upper end of the hanging flange (101), the optical fiber column (101b) is arranged on the circumferential surface of the hanging flange (101).
The thermal expansion compensation optical fiber insulator according to claim 2, characterized in that: the expansion joint (102) includes an expansion cavity (102a) and an optical fiber hole (102b), and the expansion cavity (102a) is disposed on the expansion joint. Inside the joint (102), the optical fiber hole (102b) is provided through the upper end of the expansion joint (102), and the optical fiber hole (102b) communicates with the expansion cavity (102a).
Thermal expansion compensation optical fiber insulator according to claim 3, characterized in that: the expansion joint (102) further includes a cylinder hole (102c), an engaging bump (102d) and an expansion threaded hole (102e), and the cylinder hole (102c) is provided on the side of the expansion joint (102), the engaging bump (102d) is provided on the lower end of the expansion joint (102), and the expansion threaded hole (102e) is provided on the expansion joint (102) ) at the upper end, the cylinder hole (102c) communicates with the expansion chamber (102a), and there are multiple cylinder holes (102c).
Thermal expansion compensation optical fiber insulator according to claim 4, characterized in that: the hanging flange (101) further includes a cavity (101c) and an upper threaded hole (101d), the cavity (101c) and the An upper threaded hole (101d) is provided at the lower end of the hanging flange (101). There are multiple upper threaded holes (101d). An upper screw (106) passes through the upper threaded hole (101d) and is connected to the upper threaded hole (101d). Expansion threaded hole (102e) connection;

The optical fiber column (101b) is provided with a lead-out hole (101b-1), and the lead-out hole (101b-1) communicates with the cavity (101c).
The thermal expansion compensation optical fiber insulator according to claim 4 or 5, characterized in that: the extrusion part (103) includes a piston (103a), a spring (103b) and a threaded end cap (103c), and the spring (103b) It is sleeved on the piston (103a). One end of the piston (103a) is matched with the threaded end cap (103c), and the other end is placed in the cylinder hole (102c). The threaded end cap (103c) and Place The cylinder hole (102c) is threaded.
Thermal expansion compensation optical fiber insulator according to claim 6, characterized in that: the fixing flange (104) includes a fixing groove (104a) and a fixing threaded hole (104b), the fixing groove (104a) and the fixing thread The hole (104b) is provided at the upper end of the fixed flange (104), and there are multiple fixed threaded holes (104b). The engaging convex block (102d) is placed in the fixed groove (104a). The screw (107) passes through the fixing threaded hole (104b) and is connected to the expansion threaded hole (102e).
Thermal expansion compensation optical fiber insulator according to claim 7, characterized in that: the piston (103a) includes a piston rod (103a-1) and a sliding column (103a-2), and the sliding column (103a-2) is arranged on The side of the piston rod (103a-1), the piston rod (103a-1) is placed in the cylinder hole (102c);

The piston rod (103a-1) is provided with a mounting groove (103a-11);

A sealing groove (103c-1) is provided on the side of the threaded end cap (103c), and the sliding column (103a-2) is inserted into the sealing groove (103c-1).
The thermal expansion compensation optical fiber insulator according to claim 7 or 8, characterized in that: a glue injection hole (105a) is provided at the lower end of the insulator (105), and the glue injection hole (105a) penetrates the insulator (105).
A method of using the thermal expansion compensation optical fiber insulator as claimed in claim 9, characterized in that: the optical fiber is passed through the glue injection hole (105a) and the expansion cavity (102a) out of the optical fiber hole (102b), and the piston (103a ) to the deepest position of the cylinder hole (102c);

Inject glue into the glue injection hole (105a) at the lower end of the insulator (105) at normal temperature. When the glue is injected into the fiber hole (102b), the fiber hole (102b) is sealed through the locking joint;

Continue to inject glue, causing the piston (103a) to move under the pressure of the glue fluid to the middle position of the cylinder hole (102c), and then close the glue injection hole (105a);

The optical fiber led out from the optical fiber hole (102b) passes through the cavity (101c) and out of the extraction hole (101b-1), and then passes through the upper threaded hole (101d) and the expansion threaded hole (102e) through the upper screw (106) Connect the fixed hanging flange (101) and expansion joint (102);

The engaging bump (102d) is placed in the fixing groove (104a), and is connected to the expansion threaded hole (102e) through a number of lower screws (107) passing through the fixing threaded hole (104b) to secure the fixing flange. (104) is fixed with the expansion joint (102).