JP7615352B2 - Storage boxes and opening and closing devices - Google Patents

Description

This application relates to a storage box and an opening and closing device.

The switchgear includes a switch and a storage box such as a protective box that stores the switch and prevents the switch from being exposed to foreign objects such as rain or dust. The storage box is configured to have a high level of airtightness to prevent foreign objects from entering the inside. On the other hand, since there is a possibility that the pressure inside the storage box will rise due to arcing when the current is interrupted, a pressure relief device is provided in the storage box to prevent the pressure rise when the current is interrupted. The pressure relief device is configured to prevent a sudden pressure rise inside the storage box by releasing the gas inside the storage box to the outside when the current is interrupted while maintaining the airtightness of the storage box except when the current is interrupted. As a configuration for realizing such a pressure relief device, a pressure relief structure is disclosed that includes a pressure relief hole formed in the storage box and a pressure relief lid that opens the pressure relief hole when the current is interrupted and seals the pressure relief hole except when the current is interrupted (for example, see Patent Document 1). In the pressure relief structure of Patent Document 1, an O-ring attachment member is provided around the pressure relief hole to form a convex shape, and the pressure relief lid is configured to be concave so as to cover the pressure relief hole including the O-ring attachment member. The pressure release lid transitions between an open position and a closed position by utilizing the relationship between the elastic force of the torsion coil spring and the rise in internal pressure when the current is interrupted. The pressure release lid is further provided with a locking member for holding the lid in the closed position. The pressure release lid is held in the closed position by locking the locking member with a locking member provided in the pressure release hole, thereby preventing the intrusion of foreign matter into the storage box.

JP 2003-263944 A

In the pressure relief structure of Patent Document 1, the concave shape and the attachment of the interlocking member increase the mass of the pressure relief lid compared to a pressure relief plate composed only of a simple plate-like member. As a result, greater gravity acts on the pressure relief lid. Since gravity acting on the pressure relief lid acts in a direction that slows the movement of the pressure relief lid from the sealed position to the open position, the pressure relief lid in Patent Document 1 takes longer to move from the sealed position to the open position when the current is interrupted. If the time from current interruption to pressure relief is long, the strength of the storage box needs to be increased to prepare for the increase in pressure during that time, but increasing the strength leads to a more complicated structure of the storage box and an increase in weight.

This application discloses technology to solve the problems described above, and aims to provide a storage box and an opening and closing device that can reduce the weight of the storage box while preventing foreign objects from entering the storage box.

The storage box disclosed in the present application is a storage box which stores a switch, has a pressure relief hole in a side wall for relieving internal pressure, and has a switch pressure relief device attached to the side wall, the switch pressure relief device comprising a pressure relief plate having a movable part which is movable between a sealed position which seals the pressure relief hole and an open position which opens the pressure relief hole, and a deforming part which is elastically deformable and deforms in accordance with the movement of the movable part, the movable part and the deforming part of the pressure relief plate being made of an elastically deformable resin material,
When the movable part is in the open position, the elastic force of the deformed part applies a load to the movable part in the direction returning to the sealed position, and the movable part automatically returns from the open position to the sealed position where no elastic force of the deformed part is generated .

Also, another form of a storage box disclosed in the present application is a storage box that stores a switch and has a pressure relief hole in a side wall for relieving internal pressure, and a switch pressure relief device attached to the side wall, the switch pressure relief device having a movable part that rotates around one end as a central axis and is movable between a sealed position in which the pressure relief hole is sealed and an open position in which the pressure relief hole is opened, and is equipped with a pressure relief plate with a cut-out corner at the upper end on the side wall side , a support body fixed to the side wall on both sides in the direction of the central axis, a shaft that passes through a through hole provided in the support body and is supported by the support body, and a torsion coil spring fixed to the shaft and applies a load to the movable part in a direction to maintain it in the sealed position when the movable part is in the sealed position, and applies a load to the movable part in a direction to return to the sealed position when the movable part is in the open position, the pressure relief plate has a flat plate-shaped part and an arm provided at one end of the plate-shaped part and having a hole with which the shaft fits, and the entirety rotates together with the shaft.

The storage box disclosed in this application can reduce the weight of the storage box while preventing foreign objects from entering the storage box.

FIG. 2 is a perspective view of the opening and closing device according to the first embodiment. FIG. 2 is a front view of the pressure relief device according to the first embodiment. FIG. 2 is an exploded view of components of the pressure relief device according to the first embodiment. FIG. 4 is a front view of the pressure relief plate according to the first embodiment. FIG. 11 is a front view showing another example of the pressure release plate according to the first embodiment. FIG. 11 is a front view showing another example of the pressure release plate according to the first embodiment. 4 is a perspective view illustrating a fixing method of the torsion coil spring according to the first embodiment. FIG. 2 is a cross-sectional view of the pressure relief device according to the first embodiment taken along line AA, showing the pressure relief plate in a sealed position. FIG. 2 is a cross-sectional view of the pressure relief device according to the first embodiment taken along line AA, showing the pressure relief plate in an open position. FIG. 13A and 13B are diagrams illustrating the return operation of the pressure relief plate. 11 is a cross-sectional view of the pressure relief device according to the second embodiment taken along line AA, showing the pressure relief plate in a sealed position. FIG. 11 is a cross-sectional view of the pressure relief device according to the second embodiment taken along line AA, showing the pressure relief plate in an open position. FIG. 11 is a cross-sectional view of the pressure relief device taken along line AA in embodiment 3. FIG. FIG. 13 is a front view of the pressure relief device according to the fourth embodiment.

Embodiment 1.
A first embodiment will be described with reference to Figs. 1 to 8. Fig. 1 is a perspective view of a switchgear in the first embodiment. The switchgear 1000 includes, for example, a power switchgear 100 and a storage box 91, such as a protective box, that stores the switchgear. The storage box 91 is, for example, a two-tiered box, and has a high airtightness to prevent foreign matter from entering the inside. For the sake of explanation, the coordinate axes are set as follows. That is, the vertical direction is the z-axis, and the x-axis and y-axis are set in a direction perpendicular to the z-axis, that is, in the horizontal direction. The x-axis is set in a direction along the long side of the storage box 91, and the y-axis is set in a direction along the short side of the storage box 91. The upward direction of the z-axis is set to the +z-axis direction, and the downward direction is set to the -z-axis direction. As for the x-axis and y-axis, one of them is set to the +x-axis direction and +y-axis direction, and the opposite direction is set to the -x-axis direction and -y-axis direction , as shown in Fig. 1. The upper part 91A of the storage box has a trapezoidal cross section so that the upper surface side is narrower. However, the shape of the storage box 91 is not limited to that shown in FIG.

In the upper portion 91A, the pressure relief devices 10A and 10B, i.e., the pressure relief devices of the switch, are attached to the outer surface of the side wall 91Aa along the short side direction (y-axis direction). Although not shown in FIG. 1, pressure relief holes are provided at the positions where the pressure relief devices are attached in the side wall 91Aa. In FIG. 1, the pressure relief devices are attached in pairs, one on each side wall 91Aa on both sides, but the number and attachment positions of the pressure relief devices to be attached are not particularly limited. The pressure relief device 10 may be attached to the side wall 91Ab along the long side direction (x-axis direction) of the storage box 91. In the lower portion 91B, the side wall 91Bb along the long side direction (x-axis direction) is provided with a hole (not shown) through which the bus bar 92 passes.
In the following description, the pressure relief device 10A will be described as an example.

Figure 2 is a front view of the pressure relief device in embodiment 1, and is a view of pressure relief device 10A as seen in the +x-axis direction of Figure 1. Note that the same is true for pressure relief device 10B, so hereafter it will be simply described as pressure relief device 10.

The pressure release device 10 is attached to a pressure release device mounting portion 91d provided at a predetermined position of the side wall 91Aa. The position and range of the pressure release device mounting portion 91d are not particularly limited as long as it includes the pressure release hole 91c formed in the side wall 91Aa and can form a screw hole or the like necessary for mounting the pressure release device 10. The pressure release device 10 is configured to include a pressure release plate 11 covering the pressure release hole 91c, a cover 12 covering the pressure release plate 11, and two plate-shaped members arranged on both sides of the movable part 11c of the pressure release plate 11 in the y-axis direction, and is equipped with a support body 13 fixed to the pressure release device mounting portion 91d, a shaft 14 penetrating a through hole 13aa provided in the support body 13, and a torsion coil spring 15 of a double torsion shape attached to the shaft 14. In FIG. 2, the pressure release hole 91c is two circular holes provided adjacent to each other, but the shape and number of the pressure release holes 91c are not limited to this and can be provided arbitrarily.

The pressure relief plate 11 has the same external shape as the cover 12, and is configured to prevent a gap from occurring between the cover 12 and the pressure relief device mounting portion 91d when it is attached to the pressure relief device mounting portion 91d together with the cover 12. The pressure relief plate 11 is also provided with a U-shaped slit 11a, and a movable movable portion 11c is provided in the area surrounded by the U-shaped slit 11a. The movable portion 11c moves between a sealed position where it is in close contact with the side wall 91Aa to seal the pressure relief hole 91c, and an open position where it is separated from the side wall 91Aa to open the pressure relief hole 91c, and is normally in the sealed position. For this reason, the position and range of the movable portion 11c must be configured to at least seal the pressure relief hole 91c. A more detailed configuration of the pressure relief plate 11 will be described later.

The cover 12 is attached to the pressure relief device attachment portion 91d. Although not shown in Figure 2, the cover 12 has an opening corresponding to the movable portion 11c. In addition, a grippable handle portion 12a is integrally formed on the upper portion of the cover 12. The handle portion 12a is formed by projecting both side ends in the y-axis direction of the upper portion of the cover 12 upward and connecting the projecting portions on both sides.

The support 13 is fixed integrally with the pressure relief plate 11 and cover 12 to the storage box 91 by fastening members such as bolts and nuts. The shaft 14 is rotatably supported by the support 13 by passing through the through hole 13aa. The shaft 14 is prevented from falling out of the through hole 13aa by both axial ends interfering with the inner wall of the cover 12, thereby restricting its axial displacement. The torsion coil spring 15 has a pressing portion 15b that applies a load due to the elastic force of the torsion coil spring 15 to the movable portion 11c of the pressure relief plate 11.

Figure 3 is an exploded view of the components of the pressure relief device in the first embodiment, and the dashed lines in Figure 3 indicate the assembly positions of the bolt 81 and nut 82, which are fastening members. As shown in Figure 3, a hole 91e into which the bolt 81 is inserted is provided at a predetermined position of the pressure relief device mounting part 91d. The pressure relief device 10 is attached to the storage box 91 (pressure relief device mounting part 91d) as follows. First, as shown in Figure 3, the support 13 with the torsion coil spring 15 and shaft 14 attached is inserted into the inside of the cover 12 from the opening 12b provided at the lower end of the cover 12 to form one component. Next, the pressure relief plate 11 is arranged so as to be sandwiched between the above components (cover 12, support 13, shaft 14, and torsion coil spring 15) and the pressure relief device mounting part 91d, and the above components and the pressure relief plate 11 are fastened and fixed using the bolt 81 and nut 82, thereby attaching each component to the pressure relief device mounting part 91d. At this time, the opening 12c of the cover 12 is aligned with the movable portion 11c of the pressure release plate 11. The side surface of the cover 12 on the pressure release device mounting portion 91d side is brought into close contact with the pressure release device mounting portion 91d except for the opening 12c.

Each component attached to the pressure release device mounting portion 91d is also provided with a hole for inserting the bolt 81 at a position corresponding to the hole 91e. In addition, in the first embodiment, the pressure release device 10 is attached to the pressure release device mounting portion 91d using fastening members such as the bolt 81 and nut 82, but an attachment method using other fixing members such as rivets may also be used.

Next, a more detailed configuration of the pressure release plate 11 will be described. FIG. 4A is a front view of the pressure release plate according to the first embodiment, and is a view of the pressure release plate 11 viewed in the +x-axis direction of FIG. 1. As described above, the pressure release plate 11 has the same outer shape as the cover 12, and has an outer shape with a partially recessed upper portion. A U-shaped slit 11a is provided in the vertical center of the pressure release plate 11, and a movable part 11c is provided in the range surrounded by the U-shaped slit 11a. At the upper end of the movable part 11c, at the opening of the U-shaped slit 11a, a deformation part 11b that extends in the y-axis direction and is elastically deformable is provided. The movable part 11c rotates around the y-axis with the deformation part 11b as the deformation part 11b elastically deforms. As a result, the movable part 11c opens and closes like a hinge, and the movable part 11c is movable between a closed position and an open position. The pressure release plate 11 has a fixed portion 11d other than the area surrounded by the U-shaped slits 11a. The fixed portion 11d has holes 11e into which bolts 81 are inserted, and is fixed to the pressure release device mounting portion 91d by the bolts 81 and nuts 82. The positions and number of the holes 11e correspond to the positions and number of the holes 91e of the pressure release device mounting portion 91d.

Figure 4B is a front view showing another example of the pressure release plate according to embodiment 1. In the example shown in Figure 4B, the U-shaped slit 11a is not formed. The pressure release plate 111 extends in the y-axis direction, and the elastically deformable deformation portion 111b is provided in the center in the z-axis direction. The deformation portion 111b is formed across both ends of the pressure release plate 111 in the y-axis direction, with the upper portion above the deformation portion 111b being the fixed portion 111d, and the lower portion below the deformation portion 111b being the movable portion 111c. The movable portion 111c rotates around the y-axis around the deformation portion 111b as a result of the elastic deformation of the deformation portion 111b. As a result, the movable portion 111c opens and closes like a hinge, and the movable portion 111c is movable between the closed position and the open position. The fixed portion 111d is formed with a hole 11e into which the bolt 81 is inserted, and is fixed to the pressure release device mounting portion 91d by the bolt 81 and the nut 82.

Figure 4C is a front view showing another example of the pressure release plate according to the first embodiment. The pressure release plate 112 has two linear slits 11f1 and 11f2 extending from the center of the pressure release plate 112 in the z-axis direction to the lower end at the opposing portions, and the deformation portion 112b extends in the y-axis direction between the linear slits 11f1 and 11f2 at the center of the pressure release plate 112 in the z-axis direction. In the pressure release plate 112, a movable portion 112c is formed between the linear slits 11f1 and 11f2, and a fixed portion 112d is formed in the other portion, that is, above the deformation portion 112b and below the deformation portion 112b, but at the end side in the y-axis direction from the linear slits 11f1 and 11f2. The movable portion 112c opens and closes like a hinge, and the movable portion 112c is movable between a closed position and an open position. The fixing portion 112d has a hole 11e into which a bolt 81 is inserted, and is fixed to the pressure release device mounting portion 91d by the bolt 81 and a nut 82. The straight slit 11f1 and the straight slit 11f2 correspond to a first slit portion and a second slit portion, respectively. In this manner, the pressure release plate may be configured to have two slits at positions facing each other, and the area sandwiched between these two slits may be the movable portion.

Figure 5 is a perspective view explaining a fixing method of the torsion coil spring according to the first embodiment. The coordinate axes shown in Figure 5 indicate the directions when the pressure relief device 10 is attached to the storage box 91. The support 13 is formed by bending two plate-shaped members into an L-shape, and is fixed to both sides of the movable part 11c of the pressure relief plate 11 in the y-axis direction. The support 13 has a side part 13a perpendicular to the y-axis direction and provided with a through hole 13aa through which the shaft 14 passes, a bottom part 13b perpendicular to the side part 13a (perpendicular to the x-axis direction) and provided with a hole (not shown) through which the bolt 81 is inserted, and a rising part 13c in which a part of the inner side (the side close to the movable part 11c) of the bottom part 13b is raised in the -x-axis direction, i.e., toward the shaft 14. A gap is provided between the rising part 13c and the shaft 14. The width of this gap is configured to be smaller than the thickness of the winding constituting the winding part 15a of the torsion coil spring 15. In addition, a hole 13ca is provided in the rising portion 13c. The through holes 13aa provided in the side portions 13a of the supports 13 on both sides face each other. The shaft 14 extends along the y-axis direction and is supported by the supports 13 on both sides by penetrating the through holes 13aa on both sides. Note that the support 13 is not limited to a plate-like one as long as it is configured to support the shaft 14 on both sides of the movable portion 11c in the y-axis direction. For example, the support 13 may be a box body provided with a hole through which the shaft 14 passes and fixed to the pressure relief device mounting portion 91d.

As described above, the torsion coil spring 15 has a double torsion shape, and is fixed to the shaft 14 by the shaft 14 penetrating through the two winding parts 15a. The winding part 15a is arranged inside the rising part 13c, that is, between the movable part 11c and the rising part 13c. As described above, the width of the gap between the rising part 13c and the shaft 14 is smaller than the thickness of the winding that constitutes the winding part 15a, so that the movement of the winding part 15a along the axial direction of the shaft 14 is restricted by the rising part 13c. In addition, one end of the winding part 15a extends in the -z axis direction (downward), and the winding parts 15a on both sides form a U-shaped pressing part 15b. In other words, the U-shaped pressing part 15b is connected to one end of each of the two winding parts. The pressing part 15b is the point of action of the torsion coil spring 15. The other end 15c of the winding portion 15a passes through the hole 13ca of the rising portion 13c and engages with the hole 13ca. As a result, the end 15c serves as a fixed end of the torsion coil spring 15.

Figure 6 is an A-A cross-sectional view of the pressure release device in embodiment 1, showing the state when the pressure release plate is in the sealed position. As shown in Figure 6, when the pressure release plate 11 is in the sealed position, the deformable portion 11b is not deformed, and the entire pressure release plate 11 is flat and extends in the vertical direction. The movable portion 11c is in close contact with the pressure release device mounting portion 91d, blocking the pressure release hole 91c and the opening 12c of the cover 12. The pressing portion 15b applies a load F to the movable portion 11c by the elastic force of the torsion coil spring 15 so as to press it against the pressure release device mounting portion 91d, thereby holding the movable portion 11c in the sealed position.

In addition, the side wall of the cover 12 on the +x-axis direction side (storage box 91 side) is fixed to the pressure relief device mounting part 91d without any gaps other than the opening 12c and is in close contact with the pressure relief device mounting part 91d. An opening 12b is provided at the bottom, but the lower end part 12d on the +x-axis direction side of the cover 12 is also in close contact with the pressure relief device mounting part 91d. Therefore, the cover 12 seamlessly covers the outer periphery of the movable part 11c in the sealed position. Any foreign matter that enters the cover 12 from the opening 12b is prevented from entering the storage box 91 by the movable part 11c in the sealed position. Therefore, the cover 12 having the above-mentioned structure can prevent foreign matter from entering the storage box 91 not only from the horizontal direction (x-axis direction and y-axis direction) and the upper direction, but also from the lower direction.

The pressure release operation by the pressure release device 10 will be described. FIG. 7 is an A-A cross-sectional view of the pressure release device in the first embodiment, showing the state in which the pressure release plate is in the open position. When the switch 100 stored in the storage box 91 performs a current interruption operation, the pressure inside the storage box 91 rises. As shown in FIG. 7, the increased pressure increases the load P on the movable part 11c of the pressure release plate 11 in the direction toward the outside of the storage box 91. As described above, the load F is applied to the movable part 11c mainly by the torsion coil spring 15, but when the pressure inside the storage box 91 rises and exceeds the first pressure, the load P exceeds the load F, the deformation part 11b begins to elastically deform, and the movable part 11c separates from the pressure release device mounting part 91d. The movable part 11c is pushed by the load P and rotates around the y-axis with the deformation part 11b as the center. The rotation direction is the direction in which the movable part 11c is lifted (clockwise in FIG. 7). The movable part 11c rotates until its lower end abuts against the inner wall of the cover 12, and reaches the open position shown in Fig. 7. The above-mentioned rotation of the movable part 11c also rotates the pressing part 15b of the torsion coil spring 15. When the movable part 11c reaches the open position, the lower end of the pressing part 15b and the lower end of the end part 15c also abut against the inner surface of the cover 12. The "first pressure" is determined in advance by the mass of the movable part 11c and the elastic force of the torsion coil spring 15.

When the movable part 11c moves away from the pressure relief device mounting part 91d and the blockage of the pressure relief hole 91c is released, the gas G inside the storage box 91 starts to be released to the outside of the storage box 91 through the pressure relief hole 91c and the opening 12c. By releasing the gas G to the outside of the storage box 91 in this way, pressure is released. The gas G released to the outside of the storage box 91 flows into the cover 12, but because the cover 12 covers the pressure relief hole 91c without any gaps, the gas G is released to the outside of the cover 12 only through the opening 12b.

When the movable part 11c is in the open position, the movable part 11c is subjected to a load P, a reaction force N (not shown) from the inner surface of the cover 12, a load F from the torsion coil spring 15, a load FK due to the elastic force of the deformed part 11b (omitted in FIG. 7), and gravity FG (omitted in FIG. 7). The load P acts to keep the movable part 11c in the open position, and the reaction force N prevents the movable part 11c from further rotating. The load F acts to return the movable part 11c to the sealed position as shown in FIG. 7. In addition, since the deformed part 11b tries to return to its original shape, the load FK also acts to return the movable part 11c to the sealed position. In addition, gravity FG also acts to return the movable part 11c to the sealed position. When the pressure inside the storage box 91 decreases below the second pressure due to pressure release, the force holding the movable part 11c in the open position by the load P falls below the force returning the movable part 11c to the sealed position by the load F, the load FK, and the gravity FG, and the movable part 11c starts a return operation to return to the sealed position, and finally returns to the sealed position. After returning to the sealed position, the movable part 11c is pressed against the pressure release device mounting part 91d by the pressing part 15b, closing the pressure release hole 91c. The "second pressure" is determined in advance by the mass of the movable part 11c, the elastic force of the deformation part 11b, and the elastic force of the torsion coil spring 15.

The return operation of the pressure release plate 11 will be further explained. Figure 8 is a diagram for explaining the return operation of the pressure release plate. For comparison, the pressure release plate 11 in the sealed position is shown on the left side of Figure 8, and the pressure release plate 11 in the open position is shown on the right side. First, gravity FG acts on the center of gravity 11g of the movable part 11c, but when the movable part 11c is in the open position, the movable part 11c is inclined with respect to the direction of gravity FG, so that gravity FG has a component in a direction perpendicular to the side of the movable part 11c. Also, when comparing the open position state and the sealed position state, the center of gravity 11g in the open position is in a higher position than the center of gravity 11g in the sealed position, so that the open position has a larger potential energy for gravity. Therefore, gravity FG acts to rotate the movable part 11c in a direction returning to the sealed position (counterclockwise around the y-axis in Figure 8) so that the movable part 11c returns from the open position to the sealed position and the center of gravity 11g returns to the sealed position state.

Next, regarding the elastic force of the deformation part 11b, when it is in the sealed position, the deformation part 11b is not deformed and no elastic force is generated. On the other hand, when it is in the open position, the deformation part is elastically deformed such that the +x side of the deformation part expands and the -x side contracts, and an elastic force FE is generated in the deformation part 11b to cancel this elastic deformation. Due to the elastic force FE, a load FK acts on the movable part 11c in the open position in the direction returning it to the sealed position.

Furthermore, as described above, a load F also acts on the movable part 11c from the torsion coil spring 15 (omitted from FIG. 8) in a direction returning it to the sealed position. As described above, the pressure relief device 10 is configured to automatically return the movable part 11c of the pressure relief plate 11 from the open position to the sealed position by utilizing the load F, gravity FG, and load FK.

The pressure relief plate 11 is made of a thin plate made of an elastically deformable resin material. For example, it is possible to use insulating paper containing aramid polymer fibers to form the pressure relief plate 11. There is no limit to the thickness of the pressure relief plate 11, but the thinner the pressure relief plate 11 is made, the lighter it becomes, and the load generated on the pressure relief plate 11 by the shock and vibration caused by the operation of the switch 100 becomes smaller, so the load (closing load) for holding the pressure relief plate 11 in the sealed position can be made smaller. If the closing load is smaller, a smaller torsion coil spring 15 can be used, and the pressure relief device 10 can be made smaller and lighter. In addition, if the pressure relief plate 11 is made thinner, the elastic force of the deformation portion 11b and the gravity acting on the movable portion 11c also become smaller. As described above, the elastic force of the deformation portion 11b and the gravity acting on the movable portion 11c act to move the movable portion 11c to the sealed position, so if these forces are small, it is easier to move the movable portion 11c to the open position during pressure relief. Therefore, when the switch 100 performs a current interruption operation and the pressure inside the storage box 91 rises, the movable part 11c moves to the open position in a shorter time, thereby more effectively suppressing the pressure rise inside the storage box 91. In this case, the required strength of the storage box 91 can be further reduced, and the structure of the storage box 91 can be further simplified and the weight of the storage box 91 can be further reduced.

Conversely, if the thickness of the pressure relief plate 11 is increased, the effects of weight reduction and the like described above will not be as great as when the pressure relief plate 11 is made thinner, but the strength of the pressure relief plate 11 can be increased.

According to the first embodiment, it is possible to reduce the weight of the storage box while preventing the intrusion of foreign objects into the storage box. That is, the movable part of the pressure release plate in the first embodiment is configured to realize the return from the open position to the sealed position using only the elastic force of the pressure release plate itself, the elastic force of the torsion coil spring, and gravity, and the movable part of the pressure release plate can be realized simply and lightly. Since the pressure release is performed faster when the pressure release hole is opened more widely, the faster the movable part moves from the sealed position to the open position, the faster the pressure release is performed. When the movable part is made lighter as described above, considering the influence of gravity, the lighter the movable part is, the shorter the movement from the sealed position to the open position is, and the quicker the pressure release is, so that the pressure rise in the storage box can be more effectively suppressed. When the pressure rise in the storage box can be more effectively suppressed, the strength required for the storage box is small. This allows the structure of the storage box to be simplified and the weight of the storage box to be reduced. In addition, since the upper and side parts of the pressure release plate are covered with a cover, the intrusion of foreign objects into the storage box is also prevented.

It is generally known that if the pressure inside the storage box rises when the current is interrupted, the arc inside the arc-extinguishing chamber inside the switchgear 100 becomes more likely to restrike. When the arc restrikes, the arc voltage generated by the switchgear 100 decreases, which causes a problem of longer current interruption time. However, the pressure relief device in embodiment 1 also has the effect of reducing the pressure rise inside the storage box, which makes it possible to prevent the arc from restrike and shorten the current interruption time.

In addition, since the handle is integrated into the top of the cover, there is no need to provide a separate handle to hold the storage box when transporting it, which reduces the number of parts.

In addition, the winding section is sandwiched between the raised portion on the support and the movable portion of the pressure relief plate, and the width of the gap between the raised portion and the shaft is smaller than the thickness of the windings that make up the winding section, so that the movement of the winding section along the axial direction of the shaft is restricted by the raised portion. This ensures that the position of the torsion coil spring is fixed without shifting along the axial direction of the shaft, even if vibrations and shocks occur due to the sealing and opening operations of the pressure relief device. This makes it possible to suppress variations in the load applied to the pressure relief plate.

In addition, because the cover completely covers the pressure relief hole, gas released outside the storage box 91 during pressure relief is released downward from the cover only through the opening at the bottom end of the cover. As a result, any material released along with the gas from inside the storage box is released only downward, preventing the material from scattering over a wide area and reducing the adverse effects of the material on surrounding equipment.

In addition, in the open position, the lower end of the movable part of the pressure relief plate and the lower ends of the fixed end and pressing part of the torsion coil spring abut against the inner surface of the cover, so that the reaction force from the inner surface of the cover limits the amount of movement of the movable part and torsion coil spring, preventing damage to the pressure relief plate and torsion coil spring.

Embodiment 2.
Next, the second embodiment will be described with reference to Figs. 9 and 10. The same or corresponding parts as those in Figs. 1 to 8 are denoted by the same reference numerals, and their description will be omitted. Fig. 9 is a cross-sectional view of the pressure release device in the second embodiment taken along line A-A, showing a state in which the pressure release plate is in a sealed position. Fig. 10 is a view showing a state in which the pressure release plate is in an open position. The pressure release device 20 is obtained by replacing the pressure release plate 11 of the pressure release device 10 in the first embodiment with the pressure release plate 21 shown in Figs. 9 and 10. The pressure release plate 21 has a plate-shaped portion and an arm (described later), and is made of a material that is difficult to deform elastically. For this reason, the pressure release plate 21 does not have a portion that deforms elastically like the deformation portion 11b of the pressure release plate 11, and the entire plate-shaped portion of the pressure release plate 21 is the movable portion 21c. The pressure relief plate 21 is made of, for example, an iron-based metal such as iron or stainless steel, a non-ferrous metal such as aluminum or copper, or an insulating material (thermoplastic resin or thermosetting resin) such as epoxy resin or polyethylene resin, and has greater rigidity than the pressure relief plate 11. Note that the thickness of the pressure relief plate 21 is not particularly limited, but from the viewpoint of weight reduction, it is preferable to configure it as thin as possible.

The pressure relief plate 21 has an arm 27 at the upper end of the movable part 21c. The arm 27 is made of metal, for example, and is configured to rise from the movable part 21c. When the movable part 21c is in the sealed position as shown in FIG. 9, the arm 27 extends from the movable part 21c in the -x-axis direction. The arm 27 has a hole 27a into which the shaft 14 fits, and the arm 27 and the movable part 21c are fixed to the shaft 14 that fits into the hole 27a. With this configuration, the movable part 21c can rotate together with the shaft 14. The torsion coil spring 15 is attached to the shaft 14, and the movable part 21c is held in the sealed position by the load of the torsion coil spring 15, as in the first embodiment. Also, the movable part 21c moves from the sealed position to the open position due to the increase in pressure inside the storage box 91 when the current is interrupted, as in the first embodiment. Also, although there is no effect of elastic deformation and elastic force as in the pressure relief plate 11 of embodiment 1, the pressure relief plate 21 returns to the sealed position after pressure relief, similar to embodiment 1. When the load F and gravity FG (omitted in FIGS. 9 and 10) due to the torsion coil spring 15 exceed the load P (omitted in FIGS. 9 and 10) due to the pressure inside the storage box 91, the load F and gravity FG cause the pressure relief plate 21, which is in the open position, to return to the sealed position.

The corner of the movable part 21c facing the upper storage box 91 is cut, forming a cut part 21f with the edge removed. When the movable part 21c moves from the sealed position to the open position, the side facing the upper storage box 91 is pressed against the pressure relief device mounting part 91d. At this time, if there is an edge, the edge and the -x side surface of the pressure relief device mounting part 91d may interfere with each other, and smooth movement from the sealed position to the open position may be hindered. However, by forming the cut part 21f, the cut part 21f moves so as to slide on the -x side surface of the pressure relief device mounting part 91d. Therefore, smooth movement of the movable part 21c from the sealed position to the open position is not hindered.
The rest of the configuration is the same as in the first embodiment, so the description thereof will be omitted.

According to the second embodiment, the pressure relief plate is made of a metal or resin material that has a higher rigidity and is hardly elastically deformed. This makes it possible to further improve the flame retardancy and strength of the pressure relief plate.

Embodiment 3.
Next, the third embodiment will be described based on FIG. 11. The same or corresponding parts as those in FIG. 1 to FIG. 10 are denoted by the same reference numerals, and the description thereof will be omitted. FIG. 11 is a cross-sectional view of the pressure release device in the third embodiment taken along the line A-A, showing a state in which the pressure release plate is in a sealed position. The pressure release device 30 is the pressure release device 10 in the first embodiment from which the torsion coil spring 15 has been omitted. In addition, with the omission of the torsion coil spring 15, the shaft 14 and the support 13 have also been omitted. As described above, since the deformation portion 11b has elasticity, a certain degree of sealing can be obtained with the pressure release plate 11 alone. That is, when the movable portion 11c is in the sealed position, the elastic force of the deformation portion 11b applies a load to the movable portion 11c in a direction to hold it in the sealed position. Also, as can be seen from FIG. 8, when the movable portion 11c is in the open position, the elastic force of the deformation portion 11b applies a load to the movable portion 11c in a direction to return to the sealed position. That is, even without the load F of the torsion coil spring 15, the return operation from the open position to the closed position is realized by the load due to the elastic force of the deformation portion 11b and gravity FG.
The rest of the configuration is the same as in the first embodiment, so the description thereof will be omitted.

According to embodiment 3, the torsion coil spring, shaft, and support are omitted, thereby further simplifying the configuration of the pressure relief device and further reducing the weight of the pressure relief device.

Embodiment 4.
Next, a fourth embodiment will be described with reference to Fig. 12. The same or corresponding parts as those in Figs. 1 to 11 are denoted by the same reference numerals, and their description will be omitted. Fig. 12 is a front view of a pressure release device in the fourth embodiment. The pressure release device 40 is configured by removing the handle portion 12a from the cover 12 in the first embodiment and using the cover 42.
The rest of the configuration is the same as in the first embodiment, so the description thereof will be omitted.

According to the fourth embodiment, the handle is omitted from the cover, making the cover smaller. This allows the pressure relief device to be made smaller and even lighter.

Although the present application describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations.
Therefore, countless modifications not illustrated are conceivable within the scope of the technology disclosed in the present application, including, for example, modifying, adding, or omitting at least one component, and further, extracting at least one component and combining it with a component of another embodiment.

10, 10A, 10B, 20, 30, 40 Pressure relief device, 11, 111, 112, 21 Pressure relief plate, 11a U-shaped slit, 11b, 111b, 112b Deformation portion, 11c, 111c, 112c, 21c Movable portion, 11d, 111d, 112d Fixed portion, 11f1, 11f2 Straight slit, 12, 42 Cover, 12a Handle portion, 12b, 12c Opening, 12d Lower end, 13 Support, 13a Side portion, 13aa Through hole, 13b Bottom portion, 13c Raised portion, 14 Shaft, 15 Torsion coil spring, 15a Winding portion, 15b Holding portion, 15c End portion, 21f Cut portion, 27 Arm, 91 Storage box, 91Aa, 91Ab side wall, 91c pressure relief hole, 91d pressure relief device mounting portion, 100 switch, 1000 switch device, F load, FG gravity, FE elastic force, FK load, P load

Claims (13)

A storage box for storing a switch, the storage box having a pressure relief hole for relieving internal pressure provided in a side wall, and a pressure relief device for the switch attached to the side wall,
The pressure relief device of the switch comprises:
a pressure release plate having a movable part that is movable between a sealing position that seals the pressure release hole and an opening position that opens the pressure release hole, and a deformation part that is elastically deformable and deforms in accordance with the movement of the movable part,
the movable portion and the deformable portion of the pressure release plate are made of an elastically deformable resin material,
The elastic force of the deformation portion applies a load to the movable portion in a direction returning to the closed position when the movable portion is in the open position ,
The storage box is characterized in that the movable portion automatically returns from the open position to the closed position where no elastic force is generated in the deformable portion . The storage box according to claim 1, wherein the pressure relief plate is formed with a first slit portion and a second slit portion facing each other, and the movable portion is formed in the area between the first slit portion and the second slit portion. The storage box according to claim 1, wherein the pressure relief plate has a U-shaped slit and the movable part is located within the area surrounded by the U-shaped slit. The storage box according to any one of claims 1 to 3, further comprising a torsion coil spring that applies a load to the movable part in a direction to hold the movable part in the sealed position when the movable part is in the sealed position, and applies a load to the movable part in a direction to return to the sealed position when the movable part is in the open position. The movable part is a movable part that rotates around one end as a central axis,
The rotor further includes a support fixed to the side wall on both sides in the direction of the central axis, and a shaft supported by the support through a through hole provided in the support,
5. The storage box according to claim 4, wherein the torsion coil spring is fixed to the shaft. A storage box for storing a switch, the storage box having a pressure relief hole for relieving internal pressure provided in a side wall, and a pressure relief device for the switch attached to the side wall,
The pressure relief device of the switch comprises:
a pressure relief plate having a movable part which rotates about one end as a central axis and is movable between a sealing position which seals the pressure relief hole and an opening position which opens the pressure relief hole, the corner of the upper end of which on the side wall side is cut off ;
Support bodies fixed to the side walls on both sides in the direction of the central axis;
a shaft that passes through a through hole provided in the support and is supported by the support;
a torsion coil spring fixed to the shaft, the torsion coil spring applying a load to the movable part in a direction to hold the movable part in the sealed position when the movable part is in the sealed position, and applying a load to the movable part in a direction to return to the sealed position when the movable part is in the open position,
The pressure relief plate has a flat plate-shaped portion and an arm provided at one end of the plate-shaped portion and having a hole into which the shaft fits, and the entire plate rotates together with the shaft. The storage box according to claim 5 or 6, wherein the torsion coil spring has two winding parts through which the shaft passes, and a pressing part formed in a U-shape and connected to one end of each of the two winding parts, and which applies a load to the movable part. The storage box according to claim 7, wherein the support has two plate-shaped members each bent into an L-shape, and each of the two plate-shaped members has a side portion perpendicular to the central axis and in which the through-hole is provided, a bottom portion perpendicular to the side portion, and a raised portion in which a part of the bottom portion closer to the movable portion is raised toward the shaft, and the raised portion sandwiches the winding portion and the movable portion in the direction of the central axis, and a gap having a width smaller than the thickness of the winding that constitutes the winding portion is provided between the raised portion and the shaft. 9. The storage box according to claim 1, further comprising a cover covering the upper and side surfaces of the pressure relief plate and having an opening at a lower end thereof. A cover is further provided to cover the upper and side portions of the pressure relief plate and to have an opening at a lower end thereof.
The storage box according to claim 7 or 8, wherein the pressing portion abuts against an inner surface of the cover when the movable portion is in the open position. 11. The storage box according to claim 9 or 10 , wherein a grippable handle is integrally provided on an upper portion of the cover. A storage box as described in any one of claims 1 to 11, wherein the movable part is normally maintained in the sealed position, and when the pressure rises due to a current interruption operation of the switch and exceeds a predetermined first pressure, the movable part moves to the open position to release the pressure inside the storage box, and when the pressure falls below a predetermined second pressure, the movable part returns to the sealed position. A switchgear comprising: the storage box according to claim 1 ; and a switch accommodated in the storage box.

Images