JP2006302521A - Pressure releasing device for circuit breaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure releasing device for a circuit breaker storing a switching part for switching an electric path stretched on a utility pole or the like in a case in a sealed state, which prevents large fragments from scattering outside the circuit breaker when internal short circuit is generated in the circuit breaker and inner pressure is increased, and also prevents breakage of pressure releasing port. <P>SOLUTION: In the circuit breaker stored in a case, releasing increased inner pressure from a releasing part formed by a deformation of a pressure releasing lid formed on the pressure releasing port deformed by the increase of inner pressure caused by internal short circuit, a shielding member, of which opening area is partitioned so as to have nearly the same areas, and end parts are fixed and held on the case at the peripheral part of the pressure releasing port at regular interval, is arranged on the pressure releasing port. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an improvement in a pressure release device for a cased switch in which a switch for opening and closing an electric circuit such as a high voltage distribution line is housed in a sealed state in the case.

  2. Description of the Related Art Conventionally, in a high-voltage distribution line, a switch with a case in which an opening / closing part is hermetically housed in a case for opening and closing the electric line of the distribution line is provided in a utility pole or the like.

  In the above switch, if the internal pressure in the case rises due to a short circuit accident inside the switch, the internal pressure that has been raised is safe so that the case containing the switch will not be damaged by this internal pressure. The case is provided with a pressure release device for discharging the switch to the outside of the switch.

For example, a pressure relief port formed in a case housing a switch is covered with a pressure relief plate via an O-ring to the pressure relief port, and a round hole is formed in a diagonal position on the peripheral edge of the pressure relief plate. A stopper hole formed at a diagonal position orthogonal to the diagonal position of the peripheral edge, and a notch opened at the edge, and inserted into the stopper hole and the notch, and the pressure relief plate is fixed to the case. The one mounted by is disclosed. (See Patent Document 1)
Japanese Patent Laid-Open No. 7-336822 (second page, FIG. 1)

In the invention described in Patent Document 1, when the internal gas is released when the internal pressure in the case rises, the pressure release plate has round holes provided at diagonal positions in the peripheral portion of the pressure release plate. Since the O-ring is fixed to the diagonal portion, the O-ring is not scattered.
However, although it is possible to prevent scattering of small and light members such as O-rings, it is possible to prevent large pieces of insulators used in bushings, for example, large pieces of resin used in bushings, and large resin parts. May hit the pressure release plate in a state of being deformed by releasing the internal gas, destroying the pressure release plate and scattering it to the outside of the case.

  An object of the present invention is to provide a pressure relief device for a switch that solves the above-described problems.

In order to solve the above-mentioned problem, the invention according to claim 1 is provided with a pressure relief port in a sealed case, and a pressure relief lid that is deformed by an increase in internal pressure due to an internal short circuit accident is provided at the pressure relief port. In a case-containing switch that releases the internal pressure that has risen from the formed opening,
The pressure relief port is provided with a shielding member that is partitioned so that the opening area is substantially uniform, and whose end is fixed and held at a substantially equal interval in a case around the pressure relief port. It is.

  According to a second aspect of the present invention, in the first aspect of the invention, the pressure relief lid is attached to the case via a seal member, and a bent portion toward the case side is formed at the peripheral edge of the pressure relief lid. The pressure relief lid is attached by bringing the tip of the bent portion into contact with the surface of the case.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, a fixing hole comprising a round hole penetrating the lower portion of the pressure release lid is formed, and a notch portion having an open edge is formed at the upper portion. The pressure relief lid is attached to the case with bolts and nuts through the fixing hole and the notch, and the upper part of the pressure relief lid is opened when the internal pressure is increased. is there.

  According to the first aspect of the present invention, when an internal short circuit accident of the switch occurs, the breaker provided in the pressure release port in the switch case causes scattering of large pieces of insulator inside the switch or large resin parts. The rising internal pressure can be released to the outside of the switch without taking the object out.

  In addition, the pressure relief port is reinforced by fixing and supporting the end of the shielding member around the pressure relief port where the strength of the case is weak. By fixing the part, stronger reinforcement can be performed. This prevents the case from being damaged even when the internal pressure rises due to the occurrence of an internal short circuit accident.

  According to the second aspect of the present invention, when the pressure relief lid is screwed and fixed via the sealing member, which is an elastic member, when the pressure relief lid is assembled, the bent portion provided on the peripheral edge of the pressure relief lid is provided. By abutting against the case surface, the height of the pressure relief lid with respect to the case surface is easily determined.In particular, without using a torque wrench or other tool, the screw is not overtightened and the seal member is strengthened more than necessary. Without pressing down, the airtightness inside the switch can be maintained, and the pressure relief lid can be assembled properly.

  Furthermore, the sealing member made of an elastic material is covered from the outside by a bent portion provided on the pressure relief lid, and the direct sunlight is shielded, so that the sealing member can be prevented from being deteriorated by ultraviolet rays and can be stably sealed for a long period of time. .

  According to the third aspect of the present invention, the pressure relief lid is screwed and coupled to the case by the fixing hole formed of a round hole penetrating the lower portion of the pressure relief lid and the cutout portion opened at the upper edge. As a result, when the internal pressure that has risen in the internal short circuit accident of the switch is released, only the upper side holding of the pressure release lid is released by the pressure, and the deformed opening is inclined to the opposite side with respect to the case surface. Therefore, since it is guided by the pressure relief cover so that the pressure is released upward, it is possible to prevent the pressure from being released toward the pedestrians around the installed switch.

  The best mode for carrying out the present invention will be described based on the embodiment shown in FIGS.

1 to 9 show a first embodiment.
As shown in FIG. 1, the switch 1 according to the first embodiment includes a metal case 2 in which a bottom portion having an open bottom is closed with a bottom lid 3, and an arm provided on a power pole on the top surface of the case 2. It is provided with a pillar metal fitting 4 that is fixed to the gold 19 or the like. On the side of the case 2, a bushing 7.8 made of porcelain or resin having conductors 5 and 6 connected to the wires of the distribution line at the center is provided with an elastic member such as a packing 9 a by the flange 9. Through the openings opened on both side surfaces of the case 2 and screwed with fixing means such as bolts.

  The conductors 5 and 6 provided at the central portions of the bushings 7 and 8 are fixed to the bushings 7 and 8 with nuts through an elastic member such as packing (not shown).

  A fixed electrode portion 10 is formed on the end surface of the conductor 5 that is positioned inside the case 2 and fixed to the one bushing 7, and the fixed electrode portion 10 is an end surface of the conductor 5. Are arranged so that the contact surface of the fixed contact 11 with the conductor 5 extends in the axial direction of the conductor 5 (in the direction of the center of the main body case). 12, the fixed contact 11 is attached to the conductor 5 so as not to rotate.

  The pin 12 is provided with a contact pressure spring (not shown). When a movable contact 20 described later is inserted into the fixed electrode portion 10, the contact surface of the fixed contact 11, the conductor 5, and the fixed contact. The clamping pressure necessary for energizing both the contact surface 11 and the contact surface of the movable contact 20 is generated.

  In addition, a spacer made of an insulating resin (not shown) is screwed to the contact surface of the fixed contact 11 in order to suppress chattering when the movable contact 20 is inserted. At the time of insertion, a gap is provided such that the contact surfaces of the opposed fixed contacts 11 are slightly narrower than the thickness of the movable contact 20.

  Further, the arc extinguishing chamber 13 is screwed to the arc extinguishing chamber mounting bracket 14 fixed to the inner end portion of the bushing 7 so as to accommodate the fixed contact 11 that protrudes from the bushing 7 into the case 2. Has been. Further, on the outside of the arc extinguishing chamber 13, a fixed electrode cover 15 made of an insulating synthetic resin such as rubber closely contacts the inner outer peripheral surface 16 of the bushing 7 and the concave portion 17 with the outer peripheral portion 18 of the arc extinguishing chamber 13. It is mounted to fit.

  Further, in the other bushing 8 mounted opposite to the opposite side of the bushing 7 and the stationary contact 11 and opposite to the other side surface of the case 2, the conductor fixed to the central portion of the bushing 8. A pin insertion hole 21a is formed in the inner end surface of the pin 6. The movable contact 20 is rotated by the pin 21 so that the movable contact 20 contacts and separates from the contact surface of the fixed contact 11 with the pin insertion hole 21a as a rotation axis. It is supported movably.

  An opening / closing drive shaft 22 is provided on the movable contact 20 and is connected to an opening / closing mechanism section (not shown) of the switch 1. The opening / closing drive shaft 22 and the movable contact 20 are connected to each other through a connecting link 23 made of an insulating synthetic resin. The opening / closing drive shaft 22 and the movable contact 20 are driven to open / close in conjunction with a rotation operation of a handle 24 provided outside the switch 1. The shaft 22 rotates, and the movable contact 20 connected to the opening / closing drive shaft 22 also rotates about the pin 21 as an axis. With this rotating mechanism, the movable contact 20 is brought into contact with and separated from the contact surface of the fixed contact 11 to open and close the electric circuit of the distribution line.

  Inside the switch 1, ZCT 25 and CT 26 for detecting the zero-phase current and phase current are fastened to the bushings 6 and 7 by a ZCT fixture and a CT fixture made of a synthetic resin such as rubber (not shown). The signal output of the ZCT 25 and CT 26 is sent to a control device such as a relay (not shown) provided outside via a control line (not shown) penetrating through the case 2. .

  The internal mechanism of the switch 1 has a three-phase structure as shown in FIG. 2, and the three-phase electric circuit switching mechanism is interlocked by operating the handle.

  Further, an internal insulating box 27 and a lid-side insulating box 28 made of an insulating synthetic resin are provided inside the switch 1 so as to be fixed to the case 2 or the bottom cover 3, and between the phases. The insulation performance between the inner surface of the case 2 and the bottom lid 3 is improved.

  3 is provided in the wall 2a on the back side of the case 2, and the pressure release port 30 is formed by a round hole penetrating the wall 2a on the back side of the case 2. The diameter h is set so that an opening area larger than the opening area necessary for releasing the pressure rising due to the internal short circuit to the outside can be secured. That is, the opening area is set such that the internal pressure can be discharged so that the internal pressure is not increased beyond the strength that the case 2 can withstand.

  Further, on the wall 2a located outside the pressure release port 30, through holes 31, 31, 31, 31 for screwing a pressure release lid 40 and a seal member 50, which will be described later, with bolts are located on four sides. Is formed.

  Further, as shown in FIG. 4, a shielding member 32 is attached to the pressure release port 30 from the inside of the case 2. The shielding member 32 is configured by combining a plurality of metal core members 33a and 33b, and the opening areas of the pressure release holes 34 divided (partitioned) by the core members 33a and 33b are substantially uniform. It is set to be. As shown in FIG. 4A, a section of the pressure release hole 34 by the shielding member 32 includes a cross-shaped core member 33a and an arc-shaped core member 33b facing the intersection 35 of the cross-shaped core member 33a. The center portion 35 where the cross-shaped core material 33a intersects and the end joint portion 36 of each of the core materials 33a and 33b are welded. The case 2 and the shielding member 32 are integrally formed by welding and joining the end joint portion 36 of the shielding member 32 from the inside of the case 2 to the periphery of the pressure release port 30.

  Further, as shown in FIGS. 4B and 5, the pressure relief opening 40 to which the shielding member 32 is welded is provided with a pressure relief lid 40 from the outside of the case 2, and a seal member 50 made of an elastic material to be described later. The case 2 is screwed with screws so that the inside of the case 2 is hermetically sealed. As shown in FIG. 6, the pressure release lid 40 is a substantially rectangular member formed of a metal plate, and holes for screwing the case 2 with bolts or the like are formed at the four corners of the pressure release lid 40. Is formed. One of the holes is located at the edge of the lower left corner when viewed toward the pressure release lid 40, and is a fixed hole 41 made of a round hole penetrating the pressure release lid 40. It is located at the lowest position. The other three holes 42 a to 42 c are notched holes (notches) 42 a, 42 b, 42 c which are located at the edge portions of the three corners of the pressure release lid 40 and open on the outside. The notched hole 42a in the lower right corner is formed slightly higher than the fixing hole 41 in the lower left corner, and the upper notched holes 42b and 42c are positioned at the same height on both the left and right sides.

  Further, as shown in FIG. 4B and FIG. 6, a bent portion 46 is integrally provided on the peripheral portion which is the four sides of the pressure release lid 40, and the bent portion 46 is elastic as described later. In order to avoid contact with the sealing member 50 made of a material, the facing interval between the opposing bent portions 46 is slightly wider than the diameter of the sealing member 50, and when the pressure relief lid 40 is screwed and joined, The tip of the portion 46 is configured to contact the surface of the case 2.

  Further, as shown in FIG. 4B, the seal member 50 is interposed between the pressure release lid 40 and the case 2, and the shape thereof is formed as shown in FIG. The outer shape of the seal member 50 is substantially the same as the outer shape of the pressure relief lid 40, and as shown in FIG. 8, the outer diameter of the seal member 50 is the same as the diameter h of the pressure relief port 30 and is circular. A seal member pressure release port 51 is formed. Further, a seal portion 52 having a double protrusion on the outer surface side is provided in a ring shape at the periphery of the seal member pressure release port 51, and the seal portion 52 contacts the inside of the pressure release lid 40. It comes to touch. The seal portion 52 is not formed on the inner surface side of the seal member 50, and is formed in a flat surface. Note that the seal portion 52 formed of the double protrusion as described above may also be provided in a ring shape on the inner surface side of the seal member 50.

  Further, the outer side of the seal portion 52 in the seal member 50 is formed in a plate shape, and seal member fixing holes 53, 53, 53, 53 each formed of a round hole are formed at each end edge of the four corners of the plate-like portion 50a. Has been. When the pressure relief lid 40 and the seal member 50 are mounted, the fixing holes 41 formed at the four corners of the pressure relief lid 40, the cutout holes 42 a, 42 b, 42 c, and the four corners of the seal member 50 are formed. The seal member fixing holes 53, 53, 53, 53 and the through holes 31, 31, 31, 31 formed at the four corners of the case 2 are arranged at the overlapping positions. It is supposed to be covered.

  The fixing hole 41 of the pressure relief lid 40 is provided with a bolt 43 that penetrates from the inside of the case 2 and protrudes to the outer surface, and is welded to the case 2. The sealing member 50 is attached to the bolt 43. A support portion 45 is formed which is inserted through the seal member fixing hole 53 and is fastened to the bolt 43 through the flat washer 47 from the surface of the pressure release lid 40 to fix the pressure release lid 40 to the case 2. Has been. Similarly, the other three cutout holes 42a, 42b, and 42c of the pressure relief lid 40 are inserted into the bolts 43 inserted from the inside of the case 2 through the seal member fixing holes 53, and flat. It is fixed with a nut 44 through a washer 47. It should be noted that the tightening force of the nut 44 other than the support portion 45 having the fixing hole 41 of the pressure release lid 40 is released by the pressure when the internal pressure of the case 2 reaches a predetermined pressure at which the pressure release lid 40 is to be opened. Is set to

  In this embodiment, the pressure release port 30 is provided on the side wall surface of the case 2, but may be provided on the bottom cover 3.

Next, the operation of releasing pressure will be described.
When the short circuit accident occurs and the internal pressure rises abnormally inside the switch 1 according to the first embodiment, the increased internal pressure also acts on the pressure release port 30 provided in the case 2. And the pressure-release lid 40 sealed and attached to the side surface of the case 2 of the pressure-release port 30 via the sealing member 50 made of an elastic material is pressed outward by the pressure. At this time, the three edge portions supported by the notch holes 42a, 42b, 42c in the pressure release lid 40 are bolts 43, plain washers 47 and nuts by the notch holes 42a, 42b, 42c opened. 9, the pressure relief lid 40 is bent to the opposite side with respect to the surface of the case 2 as shown in FIG. 9 with the support portion 45 fixed and supported as a fulcrum. The pressure release port 30 is opened and released while being inclined.

  As described above, the pressure release port 30 is opened with an area where the internal pressure can be released below the internal pressure that the strength of the case 2 can withstand when the switch 1 is internally short-circuited. The pressure can be discharged from the pressure release port 30 to the outside of the case 2 before the case 2 is damaged.

  Further, since the pressure release lid 40 is deformed so as to be inclined outward with the lower side as a fulcrum, this serves as a guide for the direction of discharge of the pressure released from the pressure release port 30, and the pressure is directed obliquely upward. Can do.

  Therefore, even if the switch 1 is installed on the upper part of the utility pole and the pressure is released, the pressure is released to the upper side of the switch 1 so that the pressure toward the person walking around the utility pole is obtained. No release takes place.

  Furthermore, the pressure relief opening 30 that is open and exposed is evenly pressurized because the pressure relief holes 34 are partitioned so that the opening area is substantially uniform, and the damaged large member inside the case 2 is shielded. Since it collides with the member 32 and is shielded, scattering to the outside of the case 2 is prevented, and since the four corners of the seal member 50 are also fixed with bolts, they are not separated from the case 2 and scattered. .

  In addition, since the shielding member 32 is fixed to the periphery of the pressure release port 30 and configured integrally with the case 2, the strength of the periphery of the pressure release port 30 is increased by the shielding member 32, and the case 2 may be damaged. Absent.

  Further, the length of the foot of the bent portion 46 of the pressure release lid 40 is set such that the front end of the bent portion 46 is in contact with the case 2 in a state where the surface wall of the pressure release lid 40 is in contact with the seal member 50 made of an elastic material. By setting to contact, even if it does not use special tools, such as a torque wrench, the screw is not tightened too much and the sealing member 50 which consists of an elastic material is not pressed down firmly. Therefore, the seal part 52 of the seal member 50 is in close contact with and in contact with the pressure release lid 40 while maintaining appropriate elasticity, so that the airtightness of the inside of the switch 1 by the pressure release lid 40 can be maintained. Furthermore, the cover from the outside by this bending part 46 can shield the direct sunlight to the sealing member 50, and since deterioration by an ultraviolet-ray can be prevented, a stable airtight state can be ensured for a long term.

  In this way, the present invention can create a pressure relief device that can control the pressure relief with a simple structure of the pressure relief lid 40, is safe and prevents deterioration of the seal member 50, so that the switch 1 can be used for a long period of time. It is possible to provide the switch 1 that keeps the inside airtight.

FIG. 10 to FIG.
As shown in FIG. 10A, in the second embodiment, instead of the shielding member 32 of the switch 1 of the first embodiment, a plate material having a diameter larger than the diameter of the pressure release port 30 and a large area is used. The shielding member 60 provided with the pressure release holes 61 is provided almost equally.

  The shielding member 60 is provided with a vertically long hole 62 that is narrow to the left and right when viewed from the attached shielding member 60. As a method of fixing the shielding member 60 to the case 2, as shown in FIG. 10B, an attachment member 63 having an L-shaped cross section is welded and fixed to the periphery of the pressure release port 30 inside the case 2, The protrusion 64 projecting inside the L-shaped case of the fixed mounting member 63 is inserted into the vertically long hole 62 of the shielding member 60 to fix the shielding member 60 to the mounting member 63.

  The area and arrangement of the plurality of pressure release holes 61 opened in the shielding member 60 are set so that the pressure release ports 30 are substantially equally divided as in the first embodiment. Further, pressure is applied evenly, and further, a member damaged inside the case 2 is shielded by the shielding member 60 and is prevented from scattering to the outside of the case 2.

  As described above, the shielding members 32 and 60 may have any shape that does not release the scattered matter inside the switch 1 to the outside of the switch 1 as in the first and second embodiments. The dimensions are not limited to the above, and may be formed in accordance with the internal pressure and the size of the flying object.

  Further, the method of attaching the shielding member 32 to the case 2 is not limited to the direct welding of the shielding member 32 to the case 2 as in the first embodiment, and the attachment member 63 as in the second embodiment is used. For example, it is sufficient if the pressure can be firmly fixed against an increase in internal pressure, and the periphery of the pressure release port 30 can be reinforced.

  The present invention is not limited to the case of the pole switch as described above, but a multi-circuit switch in which a plurality of switching units are housed in one case arranged on the ground in the underground distribution line. It can be used for all devices used for this purpose.

BRIEF DESCRIPTION OF THE DRAWINGS Front sectional drawing which shows the internal structure of the switch of Example 1 of this invention. The side view of the switch of FIG. The rear view which mounted | wore with the shielding member in the pressure release port of the switch which shows Example 1 of this invention. (A) is a front view of the shielding member in FIG. 3, and (b) is a cross-sectional view in which a shielding member, a sealing member, and a pressure-release lid are attached to the pressure release port. The rear view which mounted | wore with the pressure-release cover of the pressure-release opening of the switch which shows Example 1 of this invention. (A) is a front view of the pressure release lid of FIG. 5, (b) is a side view of (a). The rear view which mounted | wore the pressure release port of the switch which shows Example 1 of this invention with the sealing member. (A) is a front view of the sealing member of FIG. 7, (b) is a side view of (a), and (c) is a perspective view. The rear view in which Example 1 of the present invention opened the pressure relief lid. (A) is the front view of the shielding member which shows Example 2 of this invention, (b) is sectional drawing which attached the shielding member, the sealing member, and the pressure-release cover to the pressure release port.

Explanation of symbols

1 Switch
2 Case 30 Pressure release port 32, 60 Shield member 40 Pressure release lid 46 Bending part 50 Seal member 41 Fixing hole 42a, 42b, 42c Notch hole which is a notch part

Claims (3)

In a case-containing switch that provides a pressure relief port in a sealed case, provides a pressure relief lid that deforms due to an increase in internal pressure due to an internal short-circuit accident, and releases the internal pressure that has risen from the opening formed by the deformation ,
Opening and closing characterized in that the pressure relief opening is provided with a shielding member that is partitioned so that the opening area is substantially uniform and whose end is fixed and held at a substantially equal interval around the case around the pressure relief opening. Pressure relief device. The pressure relief lid is attached to the case via a seal member, and a bent portion toward the case is formed at the peripheral edge of the pressure relief lid, and the tip of the bent portion is brought into contact with the case surface to release pressure. 2. The switch pressure relief device according to claim 1, wherein a lid is attached. A fixing hole consisting of a round hole penetrating the lower part of the pressure relief lid is formed, and a notch with an open edge is formed in the upper part, and the pressure relief lid is bolted and nuted through the fixing hole and the notch. 3. The pressure relief device for a switch according to claim 1, wherein the pressure relief device is attached to a case so that an upper portion of the pressure relief lid is opened when the raised internal pressure is released.

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