CN103050239B - A kind of screw-type ejector of Transformer Bushing Tap signal - Google Patents

Abstract

The invention provides a threaded lead-out device for the end screen signal of a transformer bushing, which is used to lead out the leakage current on the end screen lead post of the end screen of the capacitive bushing. The outer joint on the interface of the last screen; the protective sleeve connected to the outer joint, and the protective sleeve is provided with a wire hole; the conductive rod connected to the protective sleeve through an elastic insulator; it is detachably connected with the conductive rod, and set Conversion thimbles with threaded holes for mating with threads on end screen lead posts. In this embodiment, the conversion thimbles with threaded holes of different sizes can be selected according to the different sizes of the end screen lead posts, that is, the cooperation with different end screen lead posts can be achieved as long as the step of replacing the conversion thimble is required, thus avoiding The problem of replacing the conductive rod reduces the labor intensity.

Description

A threaded lead-out device for transformer bushing end screen signal

technical field

The invention relates to the technical field of transformers, in particular to a threaded lead-out device for transformer bushing end screen signals.

Background technique

The transformer is a device that uses the principle of electromagnetic induction to change the AC voltage. It is the main equipment of the power system. It mainly realizes the step-up and step-down in the process of power transmission. The reliability of its operation directly affects the safety and stability of the power system.

Among them, the bushing is an important part of the power transformer. It mainly realizes the connection, insulation and support of the inner outlet of the transformer, and is one of the main factors that cause transformer failures. Due to the severe working conditions of bushings, they are often gradually degraded or damaged due to environmental influences, resulting in grid failures. In order to ensure the normal operation of the power grid, effective preventive tests and on-line monitoring of bushings are required.

In the normal operation of the bushing, the end screen must be grounded, so the bushing on-line monitoring device also needs to lead out the leakage current on the lead post of the end screen through the signal cable for detection and then ground it. In order to facilitate the wiring of the power failure test, most of the lead posts of the last screen are provided with threads, so it is most convenient and reliable to use threaded connection for the lead-out device of the leakage current of the last screen. If the conductive rod is directly connected to the threaded lead post, when disconnecting, with the rotation of the thread, the signal cable at the end of the conductive rod will inevitably twist and rotate, which may cause the connection of the signal cable to be disconnected, resulting in an open circuit at the end screen and endangering the bushing Safety.

In addition, in order to adapt to different sizes of lead posts, a series of conductive rods need to be installed. During the inspection, the conductive rods need to be replaced continuously to achieve the matching of different sizes of lead posts. The process of replacing the conductive rods is very complicated and serious. A waste of labor intensity.

Therefore, how to provide a threaded lead-out device for the end screen signal of the transformer bushing to reduce labor intensity is a technical problem that those skilled in the art need to solve.

Contents of the invention

The purpose of the present invention is to provide a threaded lead-out device for the end screen signal of the transformer bushing to reduce labor intensity.

In order to solve the above technical problems, the present invention provides the following technical solutions:

A threaded lead-out device for the terminal screen signal of a transformer bushing, which is used to lead out the leakage current on the terminal lead post of the terminal screen of the capacitive bushing, including:

An external joint sleeved on the interface of the end screen of the capacitive casing through the installation hole;

A protective sleeve connected to the external joint, and a wire hole is opened on the protective sleeve;

a conductive rod connected to the protective sleeve through an elastic insulating member;

It is detachably connected with the conductive rod, and is provided with a conversion thimble of a threaded hole for matching with the screw thread on the lead post of the last screen.

Preferably, in the above-mentioned device, the axis of the conductive rod coincides with the axis of the installation hole, and the side of the conductive rod close to the installation hole is provided with at least two lobes along the circumference to surround the The connection petal of the insertion hole where the conversion thimble fits, a first threaded hole is opened on the end of the conductive rod away from the installation hole, and the elastic connector is sleeved on the connection petal.

Preferably, the above-mentioned device further includes an inner conversion joint for connecting the protective sleeve and the elastic insulating member.

Preferably, in the above-mentioned device, the outer surface of the inner adapter is threadedly connected with the inner wall of the protective sleeve, and the outer surface of the inner adapter is provided with a second threaded hole.

Preferably, the above-mentioned device further includes a protective resistor with one end connected to the first threaded hole and the other end connected to the second threaded hole.

Preferably, in the above-mentioned device, the threaded hole is provided at one end of the conversion thimble close to the installation hole, and the other end of the conversion thimble is a polished rod matched with the insertion hole.

Preferably, the above-mentioned device further includes a connecting nut for connecting the outer joint and the protective sleeve.

Preferably, the above-mentioned device further includes a first limiting spring arranged on the outer surface of the protective sleeve and used to limit the movement of the connecting nut in a direction away from the outer joint; On the conductive rod, it is used to prevent the conductive rod from detaching from the second limit clip spring of the elastic insulating member.

Preferably, the above-mentioned device further includes a first sealing device for sealing the connection between the external joint and the interface of the capacitive casing end screen, and a first sealing device for sealing the external joint and the protective sleeve. the second sealing device.

Preferably, the above-mentioned device further includes a waterproof joint arranged at the wire hole.

It can be seen from the above technical solution that the present invention provides a threaded lead-out device for the terminal screen signal of the transformer bushing, which is used to lead out the current on the terminal screen lead column of the capacitive bushing terminal screen, which includes: The hole is set on the outer joint on the interface of the end screen of the capacitive casing; the protective sleeve connected to the outer joint, and the protective sleeve is provided with a wire hole; the conductive rod connected to the protective sleeve through an elastic insulating member; and The conductive rods are detachably connected, and are provided with conversion thimbles for threaded holes that are used to cooperate with the threads on the lead post of the last screen. When in use, the external joint is set on the interface of the end screen of the capacitive casing through the installation hole, and the end screen lead column and the conversion thimble are connected through thread fit. Since the conversion thimble is connected with the conductive rod, the end screen can be connected. The current on the screen lead post is transmitted to the conductive rod. During detection, the detection purpose can be achieved by detecting the current on the conductive rod. In this embodiment, the conversion thimbles with threaded holes of different sizes can be selected according to the different sizes of the end screen lead posts, that is, only by replacing the conversion thimble step, the cooperation with different end screen lead posts can be achieved, thus avoiding The problem of replacing the conductive rod reduces the labor intensity.

Description of drawings

Fig. 1 is a schematic structural diagram of a screw-type lead-out device for a transformer bushing end screen signal provided by an embodiment of the present invention;

Fig. 2 is a schematic structural view of a conductive rod provided by an embodiment of the present invention;

3 is a cross-sectional view of a conductive rod provided by an embodiment of the present invention;

Fig. 4 is a schematic structural diagram of a conversion thimble provided by an embodiment of the present invention;

Fig. 5 is a cross-sectional view of the conversion thimble provided by the embodiment of the present invention.

Detailed ways

The core of the invention is to provide a threaded lead-out device for the terminal screen signal of the transformer bushing to reduce labor intensity.

In order to enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

Please refer to Fig. 1-Fig. 5, the present invention discloses a threaded lead-out device for the end screen signal of the transformer bushing, which is used to lead out the current on the end screen lead column of the end screen of the capacitive bushing, which includes: The installation hole is set on the external joint 12 on the interface 1 of the end screen of the capacitive casing; the protective sleeve 8 connected to the external joint 12, and the protective sleeve 8 is provided with a wire hole; through the elastic insulating member 4 and the protective sleeve Conductive rod 6 connected to cylinder 8; detachably connected with conductive rod 6, and provided with conversion thimble 2 for threaded hole 21 used to cooperate with the thread on the lead post of the last screen.

When in use, the external joint 12 is set on the interface 1 of the end screen of the capacitive bushing through the installation hole, and the lead post of the end screen is connected with the conversion thimble 2 through thread fit. Since the conversion thimble 2 is connected with the conductive rod 6, Therefore, the current on the lead post of the last screen can be transmitted to the conductive rod 6, and the detection purpose can be achieved by detecting the current on the conductive rod 6 during detection. In this embodiment, the conversion thimble 2 of the threaded hole 21 of different sizes can be selected according to the different sizes of the end-screen lead posts, that is, the cooperation with different end-screen lead posts can be achieved only by replacing the conversion thimble 2 . Therefore, the problem of replacing the conductive rod 6 is avoided, and the labor intensity is reduced.

In order to ensure the convenience of connection, in this embodiment, the axis of the conductive rod 6 coincides with the axis of the installation hole, that is, the conductive rod 6 is arranged opposite to the installation hole. In order to facilitate the replacement of the conversion thimble 2 and at the same time ensure the stability of the installation of the conversion thimble 2, in this embodiment, the side of the conductive rod 6 close to the installation hole is provided with at least two petals along the circumference to form a socket that can be matched with the conversion thimble 2. Connecting flap 61 for hole. When testing, the conversion thimble 2 is inserted into the insertion hole to realize the connection between the conversion thimble 2 and the conductive rod 6 . Since the connecting petal 61 has at least two petals, the diameter of the insertion hole surrounded by it can be adjusted along with the size of the conversion thimble 2 . In order to clamp the conversion thimble 2 inserted into the insertion hole, preferably, the elastic connecting piece 4 is sleeved on the connecting flap 61 . At the same time, in order to facilitate the connection between the conductive rod 6 and the external signal cable, a first threaded hole 62 for connecting with the external signal cable is also provided on the conductive rod 6 . In the detection process, the conductive rod 6 is connected with the last screen lead post through the conversion thimble 2, so as to transfer the current on the last screen lead post to the conductive rod 6, and the external signal cable passes through the first threaded hole 62 to realize the connection with the final screen lead post. The connection of the conductive rod 6, so as to realize the purpose of detecting the current on the conductive rod 6.

In a specific embodiment, the number and length of the connecting flaps 61 are not limited, and the operator can set them according to different needs. Specifically, the connecting petals 61 may be three or four petals, and the material thereof is copper material with electrical conductivity.

In the specific embodiment, an inner adapter 3 for connecting the protective sleeve 8 and the elastic insulating member 4 is also included, that is, the connection between the protective sleeve 8 and the elastic insulating member 4 is realized through the inner adapter 3 during installation. In actual setting, the inner adapter 3 is set as a hollow structure, and the elastic insulating member 4 is clamped at the hollow position of the inner adapter 3 to realize the connection to the elastic insulating member 4 .

Preferably, the outer surface of the inner adapter 3 is threadedly connected with the inner wall of the protective sleeve 8, and the outer surface of the inner adapter 3 is provided with a second threaded hole (not shown in the figure). Those skilled in the art can understand that the connection between the inner adapter 3 and the protective sleeve 8 can also be realized through other connection methods, and all of them are within the scope of protection.

In a further embodiment, the signal extraction device at the end screen of the plug-in bushing also includes protective resistors (not shown in the figure) installed in the first threaded hole 62 and the second threaded hole. One end of the protection resistor is installed in the first threaded hole 62 , and the other end is installed in the second threaded hole. By setting the protection resistor, it can be ensured that when the external signal cable is accidentally disconnected, the end screen of the bushing can still be grounded through the protection resistor 7 to prevent the end screen of the bushing from opening and ensure the safe operation of the bushing.

The specific structure of the conversion thimble 2 in the threaded lead-out device of the transformer bushing end screen signal disclosed in a specific embodiment is that one end close to the installation hole is provided with the above-mentioned threaded hole 21, and the other end is a threaded hole 21 that can be connected with the insertion hole. Matched polished rod 22. Those skilled in the art can understand that the conversion thimble 2 only needs to have a threaded hole 21 that can fit with the lead post of the last screen and a connecting section that can fit with the insertion hole.

This embodiment also provides a connection method between the protective sleeve 8 and the outer joint 12 , specifically, the connection between the outer joint 12 and the protective sleeve 8 is realized through a connecting nut 10 . A first protrusion is provided on the side of the connecting nut 10 away from the outer joint 12 , and the inner diameter of the first protrusion is larger than the outer diameter of the protective sleeve 8 , and a second protrusion is provided on the outer side of the protective sleeve 8 accordingly. When installing, the connecting nut 10 is connected to the outer joint 12 through threads, and forms a first groove with the first protrusion, and the second protrusion on the protective sleeve 8 is just stuck in the above groove, so that the connecting nut 10 connects the outer joint 12 and the protective sleeve 8.

In addition, a second groove is provided on the outer joint 12 , and a third protrusion is correspondingly provided on the inner transfer joint 3 . During installation, the third protrusion of the inner transfer joint 3 can extend into the second groove of the outer joint 12, thereby realizing a position-limited connection. Through the above arrangement, the sealing performance of the device is effectively guaranteed, and the connection method is convenient for disassembly and assembly, which greatly reduces the labor intensity of the operator.

Specifically, an internal thread is provided on the connecting nut 10, and an external thread matched with the internal thread is correspondingly provided on the external joint 12, that is, the connection between the connecting nut 10 and the external joint 12 is realized through thread fit; the connecting nut 10 is provided with Correspondingly, a protrusion matching the groove is provided on the protective sleeve 8 , that is, the connection between the connecting nut 10 and the protective sleeve 8 is realized by inserting the protrusion into the groove. In actual production, the connecting nut 10 and the outer joint 12 can also be fixed by screws, and the connecting nut 10 and the protective sleeve 8 can be fixed by screws. This embodiment does not limit the connection method between the external joint 12 and the protective sleeve 8, as long as the connection between the two can be realized.

In the actual operation process, in order to prevent the threaded connection between the connecting nut 10 and the outer joint 12 from loosening, the connecting nut 10 falls off from the outer joint 12, in this embodiment, a device for restricting the connecting nut is set on the protective sleeve 8. 10 is the first limit snap spring 9 that moves away from the outer joint 12. When the connecting nut 10 is loose, it will be displaced relative to the outer joint 12, and when it moves to the position of the first limit jumper 9, the connecting nut 10 cannot continue to run, thereby preventing the problem that it falls off from the outer joint 12.

In addition, in order to prevent the conductive rod 6 from detaching from the elastic insulator 4 , this embodiment also provides a second limit clip 5 , specifically, the second clip 5 is arranged at the end of the conductive rod 6 away from the installation hole. Since the inner ring of the elastic insulator 4 is connected to the conductive rod 6, and the outer ring is connected to the inner adapter 3, when the lead-out wire of the last screen is pulled out from the connecting flap 61, if the conductive rod 6 is connected to the elastic insulator 4 When it is tighter, it will cause the conductive rod 6 to break away from the elastic insulating member 4 along with the lead-out line of the last screen. In the present application, the second clamp spring 5 can prevent the relative displacement between the elastic insulating member 4 and the conductive rod 6 , thereby preventing the conductive rod 6 from detaching from the device.

On the basis of the above-mentioned technical solution, in order to ensure the overall sealing of the plug-in casing end screen signal lead-out device and prevent leakage, this embodiment also includes a connection between the outer joint 12 and the end screen interface A first sealing device (not shown in the figure), and a second sealing device 11 arranged between the outer joint 12 and the protective sleeve 8 . Specifically, when the outer joint 12 is connected to the interface 1 of the capacitive casing end screen, the first sealing device ensures the sealing between the two; when the outer joint 12 and the protective sleeve 8 are tightened, the second sealing device 11 Ensure the tightness between the two. Preferably, the first sealing device and the second sealing device 11 can both be sealing gaskets, but this embodiment does not limit their specific forms.

In a further embodiment, in order to ensure the safety of the external signal cable drawn out from the wire hole, a waterproof joint 7 is provided at the wire hole. The sealing of the wire hole is realized by the waterproof joint 7 . The outer casing of the waterproof joint 7 is made of metal to ensure the strength and hardness of the waterproof joint 7 ; and the interior is made of plastic to ensure the insulation and sealing of the waterproof joint 7 . In this embodiment, the materials are not limited to the above materials, and can be selected according to different needs during actual operation.

Before on-site installation, at first all parts inside the protective sleeve 8 are installed, and the signal cable is led out through the waterproof joint 7 at the end of the protective sleeve 8 . When installing, first unscrew the grounding cap at the interface of the end screen of the bushing, screw the conversion thimble 2 that matches the thread of the lead post of the end screen on the lead post, and fix the outer joint 12 on the original ground cap through threads s position. Then align the overall structure of the previously installed protective sleeve with the outer joint 12, so that the conversion thimble 2 is just inserted into the insertion hole of the conductive rod 6, and rotate the overall structure of the protective sleeve until it cannot be rotated. At this time, the front end of the inner adapter 3 The third protrusion just snaps into the second groove of the outer joint 12. Finally, the connecting nut 10 is aligned with the external thread on the external joint 12 and tightened to realize the connection between the casing end screen and the external joint 12 .

When conducting bushing power failure test, it is necessary to remove the signal lead-out device. Unscrew the connecting nut 10 at this moment, and then pull out the overall structure of the protective sleeve, and there is no need to disassemble the outer joint 12 and the conversion thimble 2 . This disassembly method removes the protective resistor and the terminal signal cable together, which can prevent the signal cable from being twisted during removal and cause the connection to be open. At the same time, it can also avoid the hidden danger of forgetting to install the protective resistor after removing it.

Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (9)

1. A threaded lead-out device for a transformer bushing end screen signal, used to lead out the leakage current on the end screen lead post of the capacitive bushing end screen, characterized in that it includes: An external joint (12) sleeved on the interface (1) of the end screen of the capacitive bushing through the mounting hole; A protective sleeve (8) connected to the outer joint (12), and a wire hole is opened on the protective sleeve (8); A conductive rod (6) connected to the protective sleeve (8) through an elastic insulating member (4); It is detachably connected to the conductive rod (6), and is provided with a conversion thimble (2) for a threaded hole (21) that is used to cooperate with the thread on the lead post of the last screen; The axis of the conductive rod (6) coincides with the axis of the installation hole, and the side of the conductive rod (6) close to the installation hole is provided with at least two petals along the circumference to surround the conversion thimble (2) The connecting petal (61) of the matching insertion hole, the first threaded hole (62) is opened on the end of the conductive rod (6) away from the installation hole, and the elastic insulating member (4) is sleeved On said connecting flap (61). 2. The device according to claim 1, characterized in that it further comprises an inner transfer joint (3) for connecting the protective sleeve (8) and the elastic insulating member (4). 3. The device according to claim 2, characterized in that, the outer surface of the inner adapter (3) is threadedly connected to the inner wall of the protective sleeve (8), and the inner adapter (3) A second threaded hole is opened on the outer surface. 4. The device according to claim 3, further comprising a protective resistor with one end connected to the first threaded hole (62) and the other end connected to the second threaded hole. 5. The device according to claim 1, characterized in that, the threaded hole (21) is arranged at one end of the conversion thimble (2) close to the installation hole, and the other end of the conversion thimble (2) is connected to the The polished rod (22) that above-mentioned insertion hole cooperates. 6. The device according to claim 1, further comprising a connecting nut (10) for connecting the outer joint (12) and the protective sleeve (8). 7. The device according to claim 6, characterized in that, it also includes a device arranged on the outer surface of the protective sleeve (8) and used to limit the connecting nut (10) to move away from the outer joint (12). ) The first limit clip spring (9) that moves in the direction of ); and the second limit that is arranged on the conductive rod (6) to prevent the conductive rod (6) from breaking away from the elastic insulating member (4) circlip (5). 8. The device according to any one of claims 1-7, characterized in that, it also includes a seal for sealing the connection between the external joint (12) and the interface (1) of the end screen of the capacitive casing. First sealing means and second sealing means (11) for sealing said outer joint (12) with said protective sleeve (8). 9. The device according to claim 8, further comprising a waterproof joint (7) arranged at the wire hole.