JPH1080027A - Insulating spacer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure the secure contact of a movable contact to a fixed contact at the disconnector of a gas insulated switchgear by separating the interface between the inner surface of a metal ring a and a resin forming layer by the constriction in forming the resin forming layer, and tightly contacting the resin forming layer, whose interface is separated, and the outer surface of a pin. SOLUTION: For example, a metal ring 1 and a charging-part-conductor bonding metal fitting 2 are set in a split-ring metal mold, which is closed from the direction, and the mold is closed and arranged in the longitudinal direction. After air is drawn out from an resin injecting port on the metal mold, filler- adding-liquid shape resin is injected, and the resin is hardened by the heating of the metal mold. In this case, the contraction of the resin part of a width (d) is larger than the contraction of the width of a pin 12. Therefore, compressing stress (p) is generated at the side surface of the pin 12, and the part between the resin forming layer 3 and the pin 12 is brought into tight contact. Therefore, the fixing of the resin forming layer 3 to the metal ring 1 is ensured regardless of the presence of the gap between the metal ring 1 and the resin forming layer 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spacer used for insulating and supporting a charging part conductor in a cylindrical metal container, and is particularly useful for insulating and supporting the charging part conductor in a gas insulated switchgear. It is something.

[0002]

2. Description of the Related Art In a gas insulated switchgear, the components of the switchgear, that is, the charging section of the busbar, circuit breaker, disconnector, lightning arrestor, and other devices are arranged in the center of a cylindrical grounded metal container and charged. Space at predetermined intervals in the length direction.
Supported by support, and pressure filling pressure to the cylindrical ground metal container with excellent gas insulation characteristics such as SF _6. Figure 6 shows an example of a disconnector-grounding switch portion of the phase-separated in the gas insulated switchgear, the conductive rod 42 having a grounding switch fixed contact 41 to the tip insulating space - supported by the support a _1, the tip the conductor rod 52 having a main fixed contact 51 in the insulating space - is supported by support a _2, a main movable contact 53 and the grounding switch movable contact 43
Are provided so as to be able to linearly move from the outside, and the main movable contact 53 is slidably inserted into the conductor rod 42 in a direction perpendicular to the conductor bar 42, and the cylindrical grounded metal container 6 is filled with SF ₆ gas and pressurized. The disconnection is carried out by an external operation of 53, and in this disconnected state, the grounding switch side movable contact 43 is brought into contact with the grounding switch fixed contact 41 by an external operation so that the cable line can be grounded.

FIG. 7A shows an insulating spacer in a gas insulated switchgear, in which a charging part connection fitting 2 'is arranged at the center of a metal ring 1' having a concave groove 11 'along the inner peripheral surface. Then, the thermosetting resin composition 3 ′ is cast into a layer between the metal ring 1 ′ and the metal fitting 2 ′ for connecting the charging section, and a packing mounting groove 31 ′ is formed on each side surface of the resin partition wall 3 ′. For fixing to the grounded metal container, as shown in FIG. 7B, packings 62 'are respectively provided between the outer peripheral side surfaces of the resin partition wall 3' and the metal container end flanges 61 '. A structure is used in which the metal ring 1 'is mounted and bolted between the metal container end flanges 61', 61 '.

[0004] To form the insulating spacer, the metal ring and the charging portion connection metal fitting are set in a cracking mold, and the space between the metal ring and the charging portion connection metal fitting is vented. While injecting a thermosetting resin liquid and charging the resin liquid.
After that, a so-called casting method is used in which the mold is carried into a heating furnace, the resin is cured by heating, and then taken out of the furnace and removed from the mold. However, in the casting method, the heat shrinkage of the resin is considerably larger than the heat shrinkage of the metal. Heat shrinks greatly, and this shrinkage also overlaps with hardening shrinkage, so that the interface between the metal ring and the hardened resin layer is peeled off, and a gap is inevitable.

[0005] Thus, the resin layer is movable in the circumferential direction with respect to the metal ring, so that the positioning in the circumferential direction cannot be restricted, which hinders the assembly of the gas insulated switchgear. In order to eliminate such inconvenience, a recess is provided on the bottom surface of the concave groove of the metal ring, and a protrusion is formed on the outer periphery of the resin layer to be locked in the recess, and the protrusion is locked in the recess with respect to the rotation in the circumferential direction. It has been proposed to perform a function as a detent (Japanese Patent Publication No. 7-99888).

[0006]

However, even in this detent structure, a gap is formed between the metal ring and the resin layer over the entire circumference of the metal ring, and the gap in the circumferential and radial directions within this gap is reduced. Because it is inevitable,
The positioning accuracy with respect to the charged part has a limit due to the displacement based on the gap. Accordingly, in FIG. 6, the positions of the fixed contacts 41, 51 in the grounded metal container 6 are shifted within this limit, and the movable contacts 43, 53 are eccentrically contacted with the fixed contacts 41, 51. There is a fear that the contact operation of the movable contact may be hindered. In particular, in the case of the three-phase package type, the center of the insulating spacer does not coincide with the center of each phase connecting part fitting. As a result of displacing the center of the charger connection fitting in the circumferential direction by the distance aΔθ, the deviation of the center of each phase fixed contact from the center of each phase movable contact becomes significantly large, and the phase fixed contact of each phase movable contact There is a fear that contact with the child may not be possible. Furthermore, in the case of the three-phase batch type, each phase charging unit receives an alternating electromagnetic force having a frequency twice the current frequency based on the supplied current, and the resin layer of the spacer vibrates in the gap to cause noise. There is fear.

[0007] An object of the present invention is to provide a live part connecting metal fitting in a metal ring having a concave groove along the inner peripheral surface,
In an insulating spacer in which a thermosetting resin composition layer is cast between the metal fitting and the metal ring, the inner peripheral surface of the metal ring and the resin composition layer are formed by shrinkage during casting of the resin composition layer. Even if the interface is peeled off and there is a gap in the meantime, it is possible to assemble the gas insulated switchgear with high dimensional accuracy by eliminating the backlash and to fix the fixed contact at the disconnector part of the gas insulated switchgear. Insulation space that can guarantee reliable contact of the movable contact
To provide services.

[0008]

According to the present invention, there is provided an insulating space according to the present invention.
The spacer is a spacer used to insulate and support the charged part conductor in the cylindrical metal container, has a concave groove along the inner peripheral surface, and has at least one pin protruding from the concave groove bottom surface. A metal part for connecting a charged part conductor is disposed in the metal ring provided, a thermosetting resin composition layer is cast between the metal part and the metal ring, and the resin composition layer shrinks during casting. The interface between the inner peripheral surface of the metal ring and the resin composition layer is peeled off, and the interface between the exfoliated resin composition layer and the outer peripheral surface of the pin is closely contacted. The pin tip has a hemispherical surface, or the corner of the pin tip has a curvature diameter of 2 mm.
It is desirable to have the above-mentioned curved surface.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is a side view showing an example of an insulating spacer according to the present invention, and FIG. 1B is a cross-sectional view of FIG. In FIG. 1A and FIG. 1B, reference numeral 1 denotes a metal ring having a concave groove 11 along an inner peripheral surface, and a pin 12 provided on a concave groove bottom surface at a predetermined interval in a circumferential direction. Is protruding. 13
Is a resin flow passage hole formed in the metal ring 1, and 14 is a bolt insertion hole. Reference numeral 2 denotes a metal fitting for connecting the charging portion conductor, and the center of the metal fitting 2 substantially coincides with the center of the metal ring 1. Reference numeral 3 denotes a thermosetting resin composition layer cast between the metal ring 1 and the charging part conductor connection fitting 2, and the inner peripheral surface of the metal ring 1 and the resin composition due to shrinkage during casting as described later. Although the interface with the layer 3 has been peeled off, the resin composition layer 3 from which the interface has been peeled off and the outer peripheral surface of the pin 12 are in close contact. Reference numeral 31 denotes a packing mounting groove formed near the outer periphery of both side surfaces of the resin composition layer 3.

The insulating spacers shown in FIGS. 1 (a) and 1 (b) insulate one charged conductor in each cylindrical metal container for each of the three phases. It is used when supporting, but when the charging part conductor is insulated and supported by the three-phase collective type, as shown in FIG. 2, each phase charging part conductor connection fitting 2 is an equilateral triangle, and the center of the equilateral triangle is The metal ring 1 is disposed so as to substantially coincide with the center thereof.

The height of the pin is sufficiently lower than the depth of the concave groove 11 so that the presence of the pin 12 does not cause disturbance of the electric field distribution. These pins include (a) in FIG. 3 (a bottom view of a part of the metal ring) and (b) in FIG.
As shown in FIG. 3 (a), the cross-sectional view taken along the roll, and FIG. 3 at 8c), as shown in FIG.
A tip r having an arc surface with a curvature diameter of 2 mm or more, or a tip having a circular cross section and a hemisphere tip may be used. This pin can be provided integrally when casting the metal ring, or can be attached by screwing as shown in FIG. The metal ring 1 can be made of copper, aluminum, steel, an alloy of each metal, or the like, and the charging part conductor connection fitting 2 can be made of copper, aluminum, or the like. For the thermosetting resin composition, an epoxy resin can be used, and usually,
Fillers such as alumina powder, silica powder and calcium carbonate powder are added.

The above-mentioned insulating spacer is usually manufactured by a casting method. For example, in FIG. 1 (b), a metal ring 1 and a connection metal fitting 2 are set in a two-piece mold that is closed from the direction, and the mold is closed and arranged vertically, and a resin on the top of the mold is set. The resin flow passage hole 1 of the metal ring 1 from the injection port
After removing the air by depressurization after passing through 3, the filler
Inject the added liquid resin, cure the resin by heating the mold,
Thereafter, it is manufactured by releasing the mold. in this case,
Since the heat shrinkage of the resin is considerably larger than the heat shrinkage of the metal, during cooling, the resin shrinks considerably more than the metal ring, and this large shrinkage also overlaps with the curing shrinkage. As shown in FIG. 5, the interface between the metal ring 1 and the cured resin layer 3 is separated, and a gap g is generated. However, in the shrinkage of the pin 12 in the width direction, since the shrinkage of the resin portion having the width b is greater than the shrinkage of the width of the pin 12, a compressive stress p is generated on the side surface of the pin 12 and the resin composition layer 3 The outer peripheral surface of the pin 12 is in close contact with the outer peripheral surface. Therefore, despite the existence of the gap g between the metal ring 1 and the resin layer 3, the fixing of the resin layer 3 to the metal ring 1 is guaranteed.

In the above, if the resin is injected and cured in such a manner that the resin is filled in the resin flow passage hole [13 in FIG. We can expect to share a part.
In this case, it is desirable that the resin flow passage holes 13 and the pins 12 be positioned at equal intervals in the circumferential direction of the metal ring 1. In the above, as shown in FIG.
The resin layer 3 is separated from the resin layer 3 by a gap g 'due to radial contraction of the resin layer having a contraction rate higher than that of the pin, and stress is applied to the corner 321 of the separated resin surface 32. By trying to make the tip of the pin 12 hemispherical, or by making the corner 121 of the pin tip an arc surface with a large radius of curvature, the corner 321 of the resin surface 32 also has a radius of curvature. A large arc surface can be formed, and stress concentration can be sufficiently relaxed to prevent the occurrence of resin cracks.

The occurrence of the gap eliminates the effect of tensile stress on the resin layer in contact with the inner peripheral surface of the metal ring during casting, and is therefore effective in preventing cracks in the resin layer. It is appropriate to apply a mold release agent to the entire inner peripheral surface of the metal ring in advance so as to surely generate a gap on the entire inner peripheral surface of the metal ring. Further, in order to prevent a strong electric stress such as causing an electric discharge from acting on the gap, a conductive paint having excellent release properties with respect to metal and an easily adhesive property with respect to resin, for example, metal. The powder-containing silicone resin liquid is applied to the inner peripheral surface of the metal ring, and a conductive resin film can be formed on the resin layer surface separated from the inner peripheral surface of the metal ring.

The insulating spacer according to the present invention is used for a case where the components of a gas insulated switchgear, that is, the charging portion of a device such as a bus, a circuit breaker, a disconnector, etc., are insulated and supported in the center of a cylindrical grounded metal container. Used for It can also be used to insulate and support the inner conductor in the cylindrical outer conductor in a pipeline air transmission line. In this case, except for the spacer for stopping the gas, the resin layer is used to flow gas. Openings can be provided.

[0016]

In the insulating spacer according to the present invention,
Despite the presence of a gap at the interface between the metal ring and the thermosetting resin layer, the gap between the metal ring and the thermosetting resin layer can be stably held without play. The contact of the movable contact with the fixed contact of the disconnector / ground switch in the gas insulated switchgear can be performed smoothly. Further, since the thermosetting resin layer can be held without play, generation of noise due to the alternating electromagnetic force acting on the metal fitting for connecting the charged portion conductor can be eliminated. Furthermore, since the metal ring has a groove along the inner peripheral surface, by making the height of the protruding pin on the bottom of the groove shallower than the depth of the groove, despite the protrusion of the pin, Electric field disturbance can be eliminated,
The voltage resistance of the capacitor can be maintained well, and sufficient voltage resistance can be guaranteed.

[Brief description of the drawings]

FIG. 1A is a side view showing an example of an insulating spacer according to the present invention, and FIG. 1B is a cross-sectional view taken along the line B in FIG.

FIG. 2 is a side view showing another example of the insulating spacer according to the present invention.

FIG. 3 is an explanatory view showing an example of a shape of a pin of a metal ring used for an insulating spacer according to the present invention.

FIG. 4 is an explanatory view showing an example of a mounting state of a pin of a metal ring used for an insulating spacer according to the present invention.

FIG. 5 is an explanatory diagram showing a close contact state between a pin of a metal ring of the insulating spacer according to the present invention and a thermosetting resin layer.

FIG. 6 is an explanatory diagram showing an example of a disconnector / grounding switch unit in the gas insulated switchgear.

FIG. 7 is an explanatory view showing a conventional insulating spacer.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 metal ring 11 concave groove 12 pin 121 arc surface at tip of pin 2 metal part for connecting charged part conductor 3 thermosetting resin composition layer

Claims (3)

[Claims] 1. A spacer used for insulatingly supporting a charged part conductor in a cylindrical metal container, the spacer having a concave groove along an inner peripheral surface, and at least one pin on a bottom surface of the concave groove. A charging part conductor connection fitting is provided in a metal ring having a protruding portion, and a thermosetting resin composition layer is cast between the fitting and the metal ring, and the resin composition layer is cast. Insulation characterized in that the interface between the inner peripheral surface of the metal ring and the resin composition layer is peeled off due to time shrinkage, and the interface between the resin composition layer and the outer peripheral surface of the pin is closely contacted. Spacers. 2. The insulating spacer according to claim 1, wherein the tip of the pin has a hemispherical surface. 3. The insulating spacer according to claim 1, wherein the corner at the tip of the pin is formed on an arc surface.