JPH0719064Y2 - Bushing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Purpose of Invention] (Industrial field of application) The present invention relates to a bushing used for tapping an electric device.

(Prior Art) Generally, a bushing is used to draw a high-voltage conductor from the inside of an electric device. The bushing is formed by a porcelain tube inside which an insulating gas is sealed, a conductor arranged concentrically inside the porcelain tube, and an electric field mitigating shield concentrically arranged outside the porcelain tube. The length of the porcelain insulator is determined by the contamination classification, and the maintenance inspection time of the bushing is also determined according to the contamination classification.

FIG. 2 shows a bushing 1 that has been conventionally used. The bushing 1 has a cylindrical conductor 3 concentrically arranged inside a porcelain insulator 2, and an upper terminal 4 and an external connection terminal 5 of the conductor 3 are interposed therebetween. Connected to the service line 6. An upper shield ring and a lower shield ring 8 for relaxing an electric field are arranged around the upper terminal 3.

In the case of the bushing 1 configured as described above, in rainy weather, water attached to the overhead wire is guided to the upper terminal 4 through the lead-in wire 6, flows from the upper terminal 4 to the porcelain tube 2, and pollutes the porcelain tube 2. In general, the overhead wire connected to the bushing 1 is aluminum, and the water that flows along the surface of the overhead wire to the top of the bushing contains the oxidizing component of aluminum and the pollutants in the air, and the pollution caused by these causes Since it concentrates on the upper part of 2 and locally contaminates, there is a phenomenon that corrosion of the upper part of the porcelain insulator 2 is likely to proceed. Then, when the upper part of the porcelain insulator 2 is significantly contaminated, there is a fear that the insulating gas filled inside may leak from the contaminated part.

Therefore, the lower shield ring 8 is formed by forming the support member 9 into an annular and conical roof shape and fixing the ring 10 to the lower end portion thereof, so that rainwater flowing in through the service wire 6 can be guided by the lower shield ring 8. Proposed is one that is scattered to prevent the upper part of the porcelain bushing 2 from being contaminated (for example, in actual exploitation 59-12).
No. 416).

(Problems to be solved by the invention) However, the conventional ring 9 having a circular cross section has a support member 10
Since they are butt-connected with each other, step portions are formed inside and outside the connecting portion. On the step formed on the outer side, contaminants such as rainwater from the overhead wire are accumulated, and on the step formed on the inner side, contaminants caught by wind and rain are accumulated. This fouling material may cause corrosion of the stepped portion, and depending on the degree of corrosion, may cause the ring 8 to drop off and damage the porcelain bushing 2, resulting in an increase in the frequency of inspection and cleaning. Further, since it is difficult to clean the step portion formed inside, deposits may remain even after cleaning.

Therefore, an object of the present invention is to provide a bushing which suppresses adhesion of fouling substances and simplifies maintenance and inspection.

[Constitution of device]

(Means for solving the problem) Insulator tube with insulating gas sealed inside, conductor mounted concentrically inside this insulator tube, upper terminal connected to the upper part of this conductor, and fixed to this upper terminal In a bushing provided with a shield ring that relaxes an electric field around the upper terminal, a support portion extending the shield ring obliquely downward from the upper terminal and one end inscribed in the support portion and an inner peripheral side of the other end And a ring having a semi-circular cross section whose end is connected to a support member and is parallel to the axis of the bushing.

(Function) Since the outer peripheral end of the ring having a substantially semicircular cross section is inscribed in the support portion and the shield ring is formed so that the inner peripheral side is parallel to the axis of the porcelain insulator and is connected to the support portion, the ring and the support portion are formed. And can be smoothly connected, and it is possible to prevent deposits of contaminants from accumulating on the connection part.

(Embodiment) An embodiment of the present invention will be described below with reference to FIG. The same parts as those of the prior art are designated by the same reference numerals, and detailed description thereof will be omitted.

Reference numeral 1 denotes a bushing connected to a tank of an electric device (not shown). The bushing 1 includes a porcelain bushing 2, a high-voltage conductor 3 mounted in the porcelain bushing 2, and an upper terminal 3 supporting an upper portion of the conductor 3. The upper shield ring 7 and the lower shield ring 8 are provided to reduce the electric field around the upper terminal 3, and the upper terminal 3 is connected to the lead wire 6 of the overhead wire via the external connection terminal 5.

The lower shield ring 8 is fixed to the upper terminal 4, and also has a support member 9 extending outwardly and conically from the outer periphery of the upper portion of the porcelain tube 2, one end of which is inscribed and the other end of which is It comprises a ring 10 having a semi-circular cross section which is formed parallel to the axis of the porcelain bushing 2 and is connected to the support member 9.

Although the support member 9 has been described as having a linear shape, it may have a curved shape that is convex outward.

Next, the operation will be described. During rainy weather, the water attached to the overhead wire flows into the upper surface of the upper terminal 3 through the service wire 6 and the external connection terminal 5, and is lowered from the upper surface of the upper terminal 3 through the shield ring 8 without contaminating the upper portion of the insulator tube 2. Scatter to.

Therefore, according to this embodiment, the support member 9 and the ring 10 are
Since no step is formed inside and outside of the connection portion with and, corrosion due to accumulation of fouling can be prevented, and cleaning of fouling can be facilitated by rainwater, and maintenance and inspection can be simplified. In particular, since the inner peripheral side of the shield ring 10 is formed parallel to the axial center of the porcelain insulator 2, it is possible to suppress the attachment of contaminants and to easily perform cleaning during maintenance and inspection.

[Effect of device]

As described above, according to the present invention, it is possible to suppress the attachment of contaminants to the shield ring, and to obtain a highly reliable bushing that simplifies maintenance and inspection.

[Brief description of drawings]

FIG. 1 is a partial sectional view of a bushing showing an embodiment of the present invention, and FIG. 2 is a partial sectional view of a conventional bushing. 1 ... Bushing, 2 ... Insulator tube, 3 ... Conductor, 4 ... Upper terminal,
8 ... Lower shield ring, 9 ... Support member, 10 ... Ring.

Claims (1)

[Scope of utility model registration request] Claim: What is claimed is: 1. A porcelain insulator having an insulating gas sealed therein, a conductor concentrically mounted inside the porcelain insulator, an upper terminal connected to the upper portion of the conductor, and an upper terminal fixed around the upper terminal. In a bushing provided with a shield ring for relaxing an electric field, a support portion extending the shield ring obliquely downward from an upper terminal and one end inscribed in the support portion and an inner peripheral side of the other end parallel to the axis of the insulator tube. In addition, the bushing is characterized in that it is formed by a ring having a substantially semicircular cross section whose end is connected to a supporting member.