JP7729120B2 - Power cable connection work cover - Google Patents

Description

The present invention relates to a cover for power cable connection work that can cover the connection portion of a power cable when connecting the cable outdoors, allowing connection work to be carried out safely and quickly without being affected by wind and rain, even in an emergency.

In recent years, Japan has experienced a high number of earthquakes and heavy rains, and each time, lifelines such as electricity, water, sewage, and gas have suffered significant damage in various ways. In particular, there have been serious accidents recently, such as the loss of power triggered by earthquakes and the failure of emergency generators due to tsunamis, which led to a complete loss of power at nuclear power plants and the loss of cooling functions for nuclear reactors.

In addition to the enormous and widespread damage caused by such nuclear power plant accidents, recovery is not easy. Furthermore, the reduction in the supply of electricity, which is essential to our lives, has a negative impact on the development of society. For this reason, electric power companies that own and manage nuclear power plants have been studying how to quickly restore power, maintain a state in which the reactors can be cooled, and prevent the damage from spreading in the event of a total power loss due to an earthquake or other disaster.

In light of the above, electric power companies have begun to specifically consider methods for quickly restoring nuclear power plant functions in the event of a power outage and the failure of emergency generators at nuclear power plants, by installing multiple independent power sources and using these sources in an emergency. Such independent power sources include generators fixed to the ground or building, and mobile high-voltage generator vehicles. The former are pre-connected to the nuclear power plant so that they can supply power in an emergency simply by starting them up, but the latter require not only a connection to the nuclear power plant, but also connections between high-voltage generator vehicles if multiple units are to be operated in parallel.

In particular, because connecting high-voltage generator vehicles together is usually mostly done outdoors, there is the problem that, unlike the fixed generators mentioned above, the progress of the work is dependent on the weather at the time. For example, when connecting multiple high-voltage generator vehicles together in heavy wind and rain, the ends of the power cables connected to each high-voltage generator vehicle are placed on the ground, making it easy for rainwater, dust, and other particles to adhere to these ends, where the power cables connect. As a result, there are problems with electrical leakage in bad weather, which makes it easier for workers to accidentally get electrocuted, and with an increased frequency of connection failures due to dust and sand getting caught in the connections. For this reason, when connecting power cables in bad weather, workers need to work carefully while being careful not to get rainwater on them, which can be a hindrance during disasters when work must proceed quickly.

At present, no literature has been found that describes a technique for solving the above-mentioned problems with power cable connections in emergencies. As a technique for protecting power cables, for example, Patent Document 1 discloses a device for a test tent titled "Test Tent for Diagnosing Insulation Degradation of Power Cables, etc.", which is for diagnosing insulation degradation of power cables without being affected by weather.
The device disclosed in Patent Document 1 is characterized by having an insulating sheet formed in a box shape with all or part of at least one side configured to be freely opened and closed, and a support composed of a plate member formed in a plate shape on the conductor pull-out rod at the upper end of the insulator tube at the transmitting end of a steel tower or the receiving end of a factory, etc., and a cylindrical support member located approximately in the center of this plate member and made of an insulating material.

With the device disclosed in Patent Document 1 having the above configuration, when conducting insulation degradation tests on a power cable installed between the transmitting end and the receiving end, a box-shaped sheet is installed via a support to cover the transmitting end and the receiving end, preventing rain or mist from falling on the terminals of the power cable during measurement. As a result, current leakage due to wetness from rain or other sources is suppressed, and insulation degradation tests can be performed accurately. In other words, highly accurate measurements make it possible to accurately grasp the condition of power equipment, eliminating waste in equipment management and reducing the effort required for management.

Furthermore, although it is not a cover for power cables, Patent Document 2 discloses an invention entitled "Fruit Tree Covering Device" that can be easily installed near fruit trees and covers the trees to prevent rainwater from adhering to the fruit.
The invention disclosed in Patent Document 2 is characterized by having a base ring attached or mounted so as to be freely movable up and down on the upper end or upper end side of a support pole erected on the ground, and a plurality of folding skeletal bases arranged radially around the base ring, with their base ends pivotally connected to the base ring and connected so that they rotate in unison as they move from a nearly horizontal state to a nearly vertical state; force ribs extending radially from the support pole or a force rib ring fitted to the support pole, with their base ends pivotally connected to the force rib ring so that they can rotate freely up and down, and the free ends of the folding skeletal bases connected to their midpoints so that they can rotate freely; and a covering sheet stretched over the force ribs.

With the invention disclosed in Patent Document 2, which has the above configuration, the covering device can be made rod-shaped by folding the folding skeletal base and the ribs upward. As a result, the covering device is compact and easy to carry. In addition, by rotating the folding skeletal base upward or downward, the folding skeletal base and the ribs rotate in a linked and forced manner, making it possible to easily unfold and fold the covering sheet. This means that even if the weather suddenly worsens, the covering device can be easily unfolded to prevent rainwater from adhering to the fruit. And when the weather improves, the covering device can be easily folded, allowing the fruit trees to be quickly exposed to sunlight. In other words, it is possible to respond quickly to changes in the weather and carry out agricultural work efficiently.

Japanese Utility Model Application Laid-Open Publication No. 2-75915 Japanese Patent Application Publication No. 9-298958

As disclosed in Patent Document 1, if the power equipment to be measured is covered with a box-shaped sheet, it is certainly believed that the power equipment will be less likely to get wet from rain or fog. However, the invention described in Patent Document 1 is intended to enable accurate insulation degradation testing at power consumption locations such as transmission towers and factories by preventing the connection points of power cables located at high altitudes from getting wet from rain or fog. For this reason, it was not intended to be used for connecting power cables placed on the ground, and it was difficult to use it for the power cable connection work that is the subject of the present invention.

On the other hand, the invention disclosed in Patent Document 2, while a cover for fruit trees, can prevent the object from getting wet by covering it from above, and the cover can be easily set up, unfolded, and folded, allowing work to proceed flexibly even in sudden bad weather. Therefore, it is considered that it can also be used for power cable connection work. However, in the case of power cable connection work, which is the subject of the present invention, where it is necessary to prevent not only rainwater but also dust from adhering due to wind, the invention disclosed in Patent Document 2 is not configured to prevent the intrusion of dust caused by wind blowing from a substantially horizontal direction. Therefore, like Patent Document 1, it is difficult to use it for the power cable connection work, which is the subject of the present invention.
Furthermore, the invention described in Patent Document 2 requires that poles be driven into the ground to be fixed during installation, which is not a problem if the ground is soil, such as in a field, but can be difficult to fix in places like nuclear power plants where most of the ground is covered with concrete or asphalt.

The present invention was made to address these conventional problems, and its purpose is to provide a cover for power cable connection work that can be easily installed and removed when connecting power cables outdoors, and that prevents rainwater and dust from adhering to the power cable connection, allowing work to be done quickly and safely regardless of the weather, even in emergencies.

The first invention to solve the above problem is a cover for power cable connection work that covers the connection portion of a power cable when the power cable is connected outdoors while it is placed on the ground. It comprises a frame that stands upright on the ground and has an upwardly convex shape, and a sheet that is supported by the frame and has a bottom, side, and ceiling. The sheet is characterized by having a window on the bottom that exposes the connection portion of the power cable within the space formed by the sheet, and at least one entrance/exit on the side.

In the first invention with the above configuration, the frame erected on the ground has an upwardly convex shape, thereby creating a space on the ground surrounded by the frame. Furthermore, the sheet, which has a bottom surface, side surfaces, and a ceiling surface and is supported by the frame, serves to isolate the space surrounded by the side surfaces and ceiling surface from the outside world. Furthermore, the window formed in the bottom surface of the sheet serves to expose the power cable connection portion within the space by placing a power cable connection work cover so that the power cable connection portion fits within the window. Additionally, at least one opening and exit formed in the side surface of the sheet serves to allow hands or bodies to enter and exit the space within the power cable connection work cover.

There is no particular specification for the size of the power cable connection work cover, and its size can be set arbitrarily according to the size of the power cable connection part and the work content. For example, it may be a space with a volume large enough for a worker's hand to enter, or if the work content requires several workers, it may be large enough for several workers to enter and work.
Furthermore, the above-mentioned "connection portion of the power cable" refers to the end of the power cable and its surrounding area, but when the end of the power cable is connected using a connecting member (such as a branch connecting tube), the area including this connecting member is also referred to as the connection portion. This also applies hereinafter.

Next, the second invention is characterized in that, in the above-mentioned first invention, the frame has a plurality of support members, a connecting device that connects one end of the plurality of support members while supporting them in an expandable manner on the ceiling side of the seat, and a fixing means that fixes the plurality of support members in an expanded state.
In the second invention having the above configuration, in addition to the same effect as the first invention described above, the frame is made up of multiple support members, one end of each of which is pivotally supported in an deployable manner by a connector on the ceiling side of the seat, so that the multiple support members can deploy while moving away from each other around the connector, or move close to each other so as to overlap. In other words, the movement of the frame described above allows the multiple support members to deploy and unfold the seat, making it possible to unfold or fold the seat.
In addition, the deployed state of the power cable connection work covering is maintained by the fixing means that fixes the multiple support members in the deployed state. There is no particular specification for such fixing means, but it may be, for example, a stopper that can be installed directly on the connector and has a part of it positioned within the range of motion of the pivotally supported support members to restrict the movement of the support members, or it may be a structure similar to that of the connector shown as an example in the specification of this application later (see Figure 5).

A third invention is characterized in that in the first or second invention, the sheet has insertion means for drawing the power cable into the space.
In the third invention having the above configuration, in addition to the effects of the first or second invention, by allowing the end of the power cable to be drawn into the space formed by the power cable connection work cover via the insertion means, the power cable connection work cover can be prevented from resting on the power cable and the bottom portion coming off the ground, and the power cable connection work cover can be firmly installed on the ground. Note that the insertion means here is not particularly specified, but it may be, for example, a hole formed in the side portion of the sheet with a diameter approximately the same as the power cable, or a slit formed continuously from the edge of the window to the side portion of the sheet. Either of these functions to prevent the bottom portion of the power cable connection work cover from coming off the ground.

Furthermore, a fourth invention is characterized in that in the above-mentioned third invention, the insertion means is at least one slit formed from the end portion of the window to the side portion.
In the fourth invention having the above configuration, in addition to the effect of the third invention described above, when the power cable is placed below the slit, which is the insertion means, and the hand is released from the power cable connection work cover, the power cable naturally enters the slit due to its own weight, and the power cable connection work cover approaches the ground and is installed.
The placement of the slits is not particularly specified, and may be formed according to the expected placement of the power cables by the user. Also, if the placement and number of power cables to be connected are not particularly determined, forming multiple slits at predetermined intervals will allow for compatibility with various placements of power cables.

In addition, a fifth invention is characterized in that in any one of the first to fourth inventions, the sheet is made of a flame-retardant material.
The fifth invention having the above configuration has the effect of making the sheet less flammable even when it comes into contact with flames, in addition to the effect of any one of the first to fourth inventions described above.

According to the first invention described above, rainwater and dust can be prevented from entering the space formed by the sheet supported by the frame. Furthermore, by placing this power cable connection work cover so as to cover the connection portion of a power cable placed on the ground in an emergency, the connection portion of the power cable can be exposed to the space through a window formed in the sheet. As a result, rainwater and dust are prevented from adhering to the power cable connection portion, and workers can enter the space through the formed entrance and exit to perform power cable connection work.

Furthermore, because the windows can expose only the power cable connection points and their surrounding areas, the exposure of the power cables can be kept to a minimum, reducing the chances of workers coming into contact with wet power cables in bad weather.
In other words, the power cable connection work cover reduces the risk of electrical leakage or connection failure during outdoor power cable connection work, even in bad weather, allowing for safe and speedy connection work. Such a power cable connection work cover is particularly useful in nuclear power plants that have experienced a total power outage and require rapid power restoration.

Next, with the second invention described above, in addition to the same effects as the first invention, the frame can be unfolded and folded, and the fixing means can also be used to maintain the frame in an unfolded state. As a result, the power cable connection work cover can be folded when not in use, significantly reducing the effort required to secure storage space. Furthermore, folding the frame makes it easier to transport, which reduces the labor required for transportation and installation when connecting power cables at multiple locations, leading to shorter work times. In other words, in an emergency such as a complete loss of power at a nuclear power plant, recovery work can be carried out quickly.

Next, with the third invention described above, in addition to the effects of the first or second invention, the insertion means described above allows the power cable connection work cover to be kept stably installed on the ground without floating off the ground, while the power cable connection portion can be pulled into the power cable connection work cover. As a result, wind is less likely to blow in between the ground and the bottom of the power cable connection work cover, making it less likely for the power cable connection work cover to tip over or be blown away by the wind. This allows workers to concentrate on their work, improving work safety and speed.

The fourth invention described above has the same effect as the third invention, but in addition, the power cable can be inserted into the slit, which serves as the insertion means, preventing the power cable connection work cover from floating off the ground. Furthermore, such slits can be easily formed in the sheet, and by placing the power cable connection work cover on the power cable while aligning the positions of the power cable and the slit, the power cable can be easily positioned within the slit. Furthermore, because the slit remains closed when the power cable is not inserted, it is possible to prevent rainwater and dust from entering through unused slits.

Next, in the fifth aspect of the invention, in addition to the effects of any of the first to fourth aspects, even if a fire breaks out at a connection point of a power cable due to an electrical leakage or the like, the flame retardant properties of the sheet can prevent the fire from burning down completely and spreading to the surrounding area, thereby minimizing damage caused by the fire.
In particular, in the event of an emergency such as a total power outage at a nuclear power plant, the site will be in a hectic situation and workers will be easily distracted. Therefore, even if an unintentional electrical leakage occurs and a fire breaks out at the same time, the use of the power cable connection work cover of the fifth invention can prevent further damage.

1 is a perspective view of the appearance of a power cable connection work covering tool according to an embodiment of the present invention; FIG. 2 is a perspective view showing an external appearance of a modified example of the power cable connection work covering tool shown in FIG. 1 . 2 is a perspective view showing the appearance of the power cable connection work covering tool shown in FIG. 1 when placed on a connection portion of a power cable. FIG. 2A is an external perspective view of the power cable connection work covering tool shown in FIG. 1 with part of the configuration omitted, and FIG. 2B is an external perspective view showing a state in which part of the configuration of FIG. 2A is folded up. 4A is an enlarged side view of the connector within the circle in FIG. 4A, and FIG. 4B is a side view of the connector when the support members in FIG. 4A are folded close to each other.

The power cable connection work cover of the present invention will be described in detail below with reference to Figures 1 to 5. Note that all of these figures are examples of the power cable connection work cover of the present invention, and users may freely design the shape, number, etc. of the components as long as the effects and advantages of the present invention, described below, are achieved.

"1. Regarding the embodiment of the present invention"
"1-1: Structure of the embodiment of the present invention"
First, the structure of a power cable connection work covering tool according to an embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a perspective view of the exterior of a power cable connection work cover according to an embodiment of the present invention. Note that the internal structure, which cannot be seen from the exterior, is indicated by dashed lines. The dashed-dotted line is used to facilitate explanation of the sheet 3 and indicates the boundary between the side portion 3b and the ceiling portion 3c of the sheet 3. Since the detailed configuration of the connector 4 in the drawing will be described later (see FIG. 5), the reference numerals for the configuration of the connector 4 have been omitted here. Additionally, the direction upward on the paper surface is the height direction, and the downward direction is the ground side.

The power cable connection work cover 1 shown in Figure 1 comprises a frame 2 that is placed on the ground and has an upwardly convex shape, and a sheet 3 that is supported by the frame 2 and is divided into three areas: a bottom surface 3a, side surfaces 3b, and a ceiling surface 3c. The sheet 3 has a window 3d in the bottom surface 3a for exposing the connection portion of the power cable within the space formed by the sheet 3, and one entrance/exit 3e in the side surface 3b.
Furthermore, as will be described in detail later, a pair of slits 3f, 3f are formed in the sheet 3, which serve as insertion means for passing a power cable through the sheet 3, and extend from a pair of opposing side portions 3b, 3b to the ends of windows 3d, 3d that are continuous with the side portions 3b, 3b. The frame 2 is formed of four support members 2a and connectors 4 that connect one end of each of the support members 2a on the ceiling portion 3c side, so that the frame 2 has an upwardly convex shape when erected on the ground.

On the other hand, as shown in Figure 1, the frame 2 has auxiliary support members 2c for connecting adjacent support members 2a, and the support members 2a may have fixing portions 2b for installing these auxiliary support members 2c. A frame 2 equipped with such auxiliary support members 2c has increased strength and is less likely to collapse even in strong winds, making it possible to maintain work space and allowing power restoration work to proceed without interruption even in bad weather.

In addition, the power cable connection work covering tool 1 is an example of the present invention as described above, and may have the structure shown in FIG.
Figure 2 is an external perspective view of a modified example of the power cable connection work cover shown in Figure 1. Note that the internal structure that cannot be seen from the outside is shown by dashed lines. The dashed-dotted line is drawn to make it easier to explain the sheet 7 and indicates the boundary between the side portion 7b and the ceiling portion 7c of the sheet 7. The direction upward on the paper is the height direction, and the downward direction is the ground side.

The power cable connection work covering tool 5 shown in FIG. 2 has an appearance different from the power cable connection work covering tool 1 described above, and has a frame 6 that is convex upward, and a sheet 7 that is supported by this frame 6 and is divided into three areas: a bottom surface portion 7a, a side surface portion 7b, and a ceiling portion 7c.
The bottom surface 7a of the sheet 7 is formed with a window 7d that exposes the connection portion of the power cable in the space formed by the power cable connection work cover 5. The side surface 7b has an entrance 7e for allowing a worker to insert their hands or body, and further has a pair of slits 7f that extend from the pair of opposing side surfaces 7b to the ends of the windows 7d that are continuous with the side surfaces 7b. In addition, the frame 6 is formed with four support members 6a and connectors 8 that connect these support members 6a on the ceiling surface 7c side.

As shown in Figure 2, the power cable connection work cover 5 described above has a different shape from the power cable connection work cover 1, but they basically share the same components. Therefore, the power cable connection work cover 5 can achieve the same functions and effects as the power cable connection work cover 1 described above. In addition, the power cable connection work cover 5 can be installed and manufactured using the same methods as the power cable connection work cover 1 described below.

[1-2: Installation method of the present invention]
Next, a method for installing the power cable connection work covering tool 1 will be specifically described with reference to FIG.
3 is a perspective view of the power cable connection work cover shown in FIG. 1 when placed on the connection portion of the power cable. In order to avoid cluttering the drawing, only some of the power cables are labeled with reference numerals, and some elements that are irrelevant to the explanation are omitted.
3 illustrates a case in which three high-voltage generator cars are connected in parallel, with a total of nine power cables (hereinafter referred to as power cables 9a) from the high-voltage generator cars being connected and aggregated into three power cables (hereinafter referred to as power cables 9b) to the nuclear power plant buildings. Specifically, six power cables 9a on the front side of the drawing and three power cables 9a on the left side of the drawing are connected in parallel via two linked branch connection tubes 10, 10, and are connected and aggregated into three power cables 9b that extend upward in the drawing. As mentioned above, the connection portions of the power cables include not only the connected ends of the power cables 9a and 9b but also the branch connection tube 10.

When installing the power cable connection work cover 1, as shown in Figure 3, a worker first places the power cable connection work cover 1 on the ground so that the ends (not shown) of the 12 power cables 9a, 9b to be connected are positioned inside the window 3d. Next, the worker carries the branch connection tube 10 through the entrance 3e into the space formed by the power cable connection work cover 1. Note that the branch connection tube 10 may be placed near the ends of the power cables 9a, 9b before the power cable connection work cover 1 is placed.
Next, the worker places his or her body inside the space formed by the power cable connection work covering 1 (or, depending on the size of the power cable connection work covering 1, only his or her hands may be placed inside) and connects a total of 12 power cables 9a, 9b using the branch connection tube 10. Once this connection is complete, the connection work is completed by removing the power cable connection work covering 1. Apart from installing the power cable connection work covering 1 while adjusting it so that it covers the connection portions of the power cables 9a, 9b, this is the same as normal connection work, and even someone unfamiliar with the work can easily perform it.

[1-3: Actions and Effects of the Present Invention]
The power cable connection work covering tool 1 described above is considered to have the following effects.
First, the frame 2 erected on the ground has an upwardly convex shape, which serves to form a space on the ground surrounded by the frame 2. Then, the sheet 3 supported by the frame 2 and having a bottom surface 3a, side surfaces 3b, and a ceiling surface 3c serves to isolate the space from the outside world.
The window 3d formed in the bottom surface 3a of the sheet 3 exposes the connection portions of the power cables 9a, 9b in the space formed by the sheet 3, allowing a worker to touch the connection portions of the power cables 9a, 9b within the space. In addition, at least one entrance 3e formed in the side surface 3b of the sheet 3 allows a worker to enter and exit the power cable connection work covering 1 with his or her hands and body.

Due to the above-mentioned action, the power cable connection work covering tool 1 is considered to have the following effects.
First, the frame 2 and the sheet 3 supported by this frame 2 form a space on the ground that is protected from wind and rain. Then, by adjusting and installing this power cable connection work cover 1 so that it covers the connection portions of the power cables 9a, 9b that are placed on the ground in an emergency (see FIG. 3 ), the connection portions of the power cables 9a, 9b can be exposed through the window 3d into the space. As a result, workers can connect the power cables 9a, 9b in an environment where the connection portions of the power cables 9a, 9b are not exposed to wind and rain. In other words, electrical leakage and connection failures are less likely to occur during the connection work of the power cables 9a, 9b regardless of the weather, allowing workers to proceed with the work safely and quickly. This power cable connection work cover 1 is considered useful in situations where a disaster occurs at a nuclear power plant, such as when all power sources are lost, and rapid power restoration is required.

In addition, by appropriately adjusting the size and shape of the window 3d, it is possible to expose only the connection points of the power cables 9a and 9b, further reducing the frequency with which workers unintentionally come into contact with areas other than the connection points of the power cables 9a and 9b that become wet in bad weather. This prevents workers from accidentally coming into contact with the power cables, and ultimately reduces the occurrence of electric shock accidents during work.

[1-4: Regarding the manufacturing method of the present invention]
Next, a method for manufacturing the power cable connection work cover 1 will be described. Regarding the manufacturing method of the power cable connection work cover 1, there are no particular specifications for the materials used for each component. Considering the environment in which the work is used and portability, the four support members 2a (and auxiliary support members 2c) constituting the frame 2 may be made of lightweight metals such as aluminum or unbreakable wire rods made of fiber-reinforced resin. The sheet 3 is also not particularly specified, but to prevent rainwater and dust from entering the power cable connection work cover 1, a sheet made of a material with low breathability and water permeability, such as synthetic resin (including rubber), or a sheet with low breathability and water permeability made of cloth coated with synthetic resin may be used. Since such sheets are commercially available, using a commercially available product not only allows the power cable connection work cover 1 to be manufactured inexpensively, but also facilitates replacement or repair in the event of damage. Regarding the connector 4 connecting the ends of the four support members 2a, there are no particular specifications as long as it can securely fasten the support members 2a. It can be manufactured by processing or molding materials such as metal or resin using well-known techniques.

Next, an example of a procedure for manufacturing the power cable connection work covering tool 1 using the above-described members will be described.
When manufacturing the power cable connection work cover 1, first, one end of each of the four support members 2a is connected and fixed to the connector 4 by a known fixing technique (adhesive, screw fixing, etc.), thereby forming the frame 2. Separately from the frame 2, a bag-shaped sheet corresponding to the side portions 3b and the ceiling portion 3c is produced by processing a sheet made of resin or the like by a known processing technique. This bag-shaped sheet is then placed over the frame 2 and fastened or fixed with string, adhesive, etc., and a sheet corresponding to the bottom portion 3a, where the window 3d is formed, is then bonded to the ground-facing periphery of the side portion 3b by adhesive, etc., thereby producing the sheet 3 supported by the frame 2. Furthermore, the side portions 3b of this sheet 3 are cut with scissors or the like to form an entrance/exit 3e, thereby completing the power cable connection work cover 1.
The above is an example, and the entrance 3e may be formed in advance at a predetermined location on the side surface portion 3b before the bag-shaped sheet is attached or fixed to the frame 2.

On the other hand, the entrance 3e may be provided with a slide fastener, a hook-and-loop fastener, or the like, so that it can be opened and closed freely. With such an entrance 3e, if the slide fastener is kept closed, it will not open due to wind pressure, so it is possible to reliably prevent rainwater and dust from entering the power cable connection work covering device 1 in bad weather.
Furthermore, as will be described in detail later, when forming the slits 3f as shown in FIG. 1, which are insertion means for inserting the power cables 9a, 9b into the power cable connection work covering device 1, the slits 3f can be easily formed by cutting the sheet 3 supported by the frame 2 with scissors or the like, in the same manner as the entrance/exit 3e.

"2. Detailed structure of the present invention"
"2-1: About the frame structure"
The frame 2 may include support members 2a, connectors 4 that connect one ends of the support members 2a while pivotally supporting them in an deployable manner on the ceiling portion 3c side of the seat 3, and fixing means that fix the support members 2a in the deployed state. The frame 2 having such a structure will be described with reference to Figures 4 and 5.
Fig. 4(a) is a perspective view of the power cable connection work covering tool shown in Fig. 1 with the sheet, which is a part of the configuration, omitted, and Fig. 4(b) is a perspective view of the power cable connection work covering tool shown in Fig. 1 with the frame, which is a part of the configuration of Fig. 4(a), folded up. Note that the description of the components that have already been explained will be omitted. In addition, in Fig. 4(b), the auxiliary support member 2c shown in Fig. 4(a) has been removed and its illustration is omitted.

Figure 4 shows a frame 2 consisting of four support members 2a and connectors 4 that connect these support members 2a. In Figure 4(a), each support member 2a is connected to the adjacent other support members 2a by auxiliary support members 2c.
Here, the connector 4 supports one end of each of the four support members 2a by a shaft (not shown), and each support member 2a can rotate around that shaft. As a result, the four support members 2a can be deployed so as to move apart from each other as shown in Figure 4(a) or moved closer to each other as shown in Figure 4(b). It goes without saying that the auxiliary support members 2c in Figure 4(b) are detached from the fixing parts 2b installed on each support member 2a in order to prevent the rotation of the support members 2a.

In addition, the connector 4 may be provided with a fixing means for maintaining the support member 2a in an expanded state as shown in Fig. 4(a) . Such a connector 4 and fixing means will be described with reference to Fig. 5 .
Fig. 5(a) is an enlarged side view of the connector 4 of Fig. 4(a), and Fig. 5(b) is a side view of Fig. 5(a) when the multiple support members are folded close to each other. Note that the description of the components that have already been described will be omitted.
As shown in Figures 5(a) and (b), the connecting device 4 is composed of a support shaft 4a, a first connecting portion 4b through which the support shaft 4a is slidably inserted and which supports one end of each of the multiple support members 2a by a shaft (not shown) so that the connecting member 4a can be expanded approximately radially, a second connecting portion 4c which is fixed to one end of the support shaft 4a and rotatably supports the other end of a connecting rib 4e, one end of which is rotatably supported by a third connecting portion 4f installed on each of the support members 2a, and a stopper 4d which protrudes at a predetermined position on the outer surface of the support shaft 4a so as to be able to return to its original position by a biasing means such as a spring.
As shown in FIG. 5, a string 4g may be attached to the end of the support shaft 4a on the side that is not fixed to the second connecting portion 4c, for pulling to apply force to the support shaft 4a or for making the power cable connection work cover 1 easier to transport.

As explained in Figure 4, with the power cable connection work cover 1 equipped with the above-described connector 4, the four support members 2a that make up the frame 2 are pivotally supported by the first connector 4b, allowing them to be deployed away from each other around the connector 4 (corresponding to Figure 5(a)) or moved closer to each other (corresponding to Figure 5(b)). In other words, with the power cable connection work cover 1, the frame 2 can be deployed and folded as easily as with an umbrella.

Next, a fixing means for fixing the support member 2a in the deployed state as shown in FIG. 5(a) will be described.
As described above, the rotation of the support member 2a pivotally supported by the first connecting portion 4b is restricted by the connecting rib 4e, one end of which is pivotally supported by the second connecting portion 4c and the other end of which is pivotally supported by the third connecting portion 4f. When the support member 2a is positioned as shown in Fig. 5(a), if the first connecting portion 4b is fixed so as not to change the distance between the first connecting portion 4b and the second connecting portion 4c, the support member 2a will be fixed in the expanded state as shown in Fig. 5(a).

Here, the stopper 4d of the connecting device 4 that protrudes from the support shaft 4a has the effect of preventing the first connecting portion 4b from climbing over the stopper 4d and moving toward the end of the support shaft 4a where the string 4g is installed (the change from Figure 5(a) to Figure 5(b)), thereby fixing the position of the first connecting portion 4b so that it does not move upward on the page in Figure 5.
Needless to say, by pushing the stopper 4d into the support shaft 4a and moving the first connecting part 4b upward in the axial direction of the support shaft 4a in the plane of the paper in Figure 5, the support member 2a will be gradually folded while being pulled by the connecting ribs 4e.
In addition, by installing the string 4g, when holding the first connecting part 4b with one hand and moving the support shaft 4a (i.e., putting the support member 2a into an unfolded state), the support shaft 4a can be moved by pulling the string 4g without directly holding it.

As a result of the above-described action, the power cable connection work cover 1 can be unfolded or folded by changing the distance between the first connecting part 4b and the second connecting part 4c using a hand, just like an umbrella, and the frame 2 (i.e., the power cable connection work cover 1) can be maintained in the unfolded state by the stopper 4d, which is a means for fixing the unfolded state.
As described above, since the power cable connection work cover 1 can be folded when not in use, the space required for storing the power cable connection work cover 1 can be reduced, and there is no need to worry about finding a storage location. Furthermore, the power cable connection work cover 1 can be easily transported by folding it, reducing the labor required for transportation. Furthermore, since it is easy to install, it is possible to significantly reduce the work time, especially when power cables 9a, 9b must be connected at multiple locations. Therefore, even in an emergency such as a total power loss at a nuclear power plant, restoration work can be carried out quickly, minimizing damage.

"2-2: Regarding cases where an insertion means is formed on the sheet"
Next, the sheet 3 may have insertion means for pulling the power cables 9a and 9b into the power cable connection work covering device 1, as shown in FIG.
There is no particular designation for such insertion means, but it may be, for example, a pair of slits 3 f, 3 f formed continuously from the ends of the windows 3 d, 3 d to the side surface portions 3 b, 3 b as shown in FIG. 1, or, although not shown in the present specification, a desired number of holes, for example, one, three or more, through which the power cables 9 a, 9 b can be inserted may be formed in the side surface portion 3 b.
With the power cable connection work cover 1 having the above-mentioned insertion means, the power cables 9a, 9b can be pulled into the power cable connection work cover 1 through an insertion means such as the slit 3f shown in Figure 3, so there is no risk of the power cables 9a, 9b creating a step that causes the power cable connection work cover 1 to be raised above the ground.
1, when the insertion means is the slit 3f, the power cable connection work cover 1 is simply placed on the power cables 9a, 9b so that the power cables 9a, 9b are arranged along the slit 3f in the bottom surface 3a. When the power cable connection work cover 1 is released, it moves downward by its own weight, and takes the power cables 9a, 9b into the slit 3f.

The above action allows the power cables 9a, 9b to be easily pulled in without lifting the power cable connection work cover 1 off the ground, and the power cable connection work cover 1 can be stably installed on the ground. As a result, wind does not blow in between the ground and the power cable connection work cover 1, making the power cable connection work cover 1 less likely to tip over or be blown away by the wind. This allows workers to concentrate more on their work, even in bad weather, and further improves work speed.

When the insertion means are slits 3f, they can be easily formed by simply cutting the sheet 3 with scissors or the like, and because they are not holes, they remain closed when the power cables 9a, 9b are not inserted. Therefore, for example, even if multiple slits 3f are formed in the power cable connection work cover 1 and the power cables 9a, 9b are not inserted into all of the slits 3f during connection work, the slits 3f through which the power cables 9a, 9b are not inserted remain closed, making it possible to prevent rain and dust from entering unless there is a strong wind.
On the other hand, when strong winds cause the sheet 3 around the slits 3f to flap, the slits 3f open, creating a gap that can allow rainwater and dust to blow in. To prevent such gaps from forming, hook-and-loop fasteners, slide fasteners, etc., can be installed to close the slits 3f. This makes it difficult for rainwater and dust to enter through the slits 3f, even in strong winds. As a result, work safety is further improved, and work speed can also be further improved.

"2-3: Regarding cases where the sheet is made of flame-retardant material"
Additionally, the sheet 3 may be made of a flame-retardant material. If the sheet 3 is made of a flame-retardant material, it will be less likely to burn even if it comes into contact with a flame.
There are no particular restrictions on the type of flame-retardant sheet that can be used as sheet 3. For example, a fabric coated with a flame retardant or a fabric woven from fibers of a resin that is itself highly flame-retardant may be used. Specific examples include a polyester or polyamide fiber fabric coated with a highly flame-retardant vinyl chloride resin, and a fabric woven from fibers of a highly flame-retardant resin such as polyphenylene sulfide.

Due to the above-mentioned action, even if a fire occurs due to a short circuit or the like during the connection work of the power cables 9a, 9b and the flames come into contact with the sheet 3, the sheet 3 of the power cable connection work cover 1 has enhanced self-extinguishing properties, so it is possible to prevent the fire from burning down completely or spreading to the surrounding area. As a result, even if a fire breaks out, damage can be kept to a minimum.
In particular, in the event of an emergency such as a total power loss at a nuclear power plant, the site is expected to be in a hectic situation. As a result, workers are likely to become distracted, increasing the possibility of unintentionally causing a short circuit. Even in such a fire, the use of the power cable connection work cover 1 can ensure the safety of workers.

As described above, the present invention is a power cable connection work cover that can cover the area around the power cable connection point when connecting power cables outdoors, and can be used in technical fields related to power cable connection devices in emergencies.

1...Power cable connection work cover 2...Frame 2a...Support member 2b...Fixing portion 2c...Auxiliary support member 3...Sheet 3a...Bottom portion 3b...Side portion 3c...Ceiling portion 3d...Window 3e...Doorway 3f...Slit 4...Connector 4a...Support shaft 4b...First connecting portion 4c...Second connecting portion 4d...Stopper 4e...Connecting rib 4f...Third connecting portion 4g...String 5...Power cable connection work cover 6...Frame 6a...Support member 7...Sheet 7a...Bottom portion 7b...Side portion 7c...Ceiling portion 7d...Window 7e...Doorway 7f...Slit 8...Connector 9a, 9b...Power cable 10...Branch connection tube

Claims (4)

A cover for power cable connection work for covering a connection part of a power cable laid on the ground outdoors ,
a frame erected on the ground and having an upwardly convex shape;
a seat supported by the frame and having a bottom surface, side surfaces, and a ceiling surface;
The sheet is
a window formed as an opening in the bottom surface portion to allow the connection portion of the power cable to pass through ;
The side portion has at least one opening and closing port ,
The sheet has at least one slit formed from the edge of the window to the side surface for pulling the power cable into a space formed therein . The frame is
A plurality of support members;
A connector that connects one ends of the plurality of support members while pivotally supporting them in an deployable manner on the ceiling portion side of the seat;
2. The power cable connection work covering tool according to claim 1, further comprising: fixing means for fixing the plurality of support members in an expanded state. 3. The power cable connection work cover according to claim 1, wherein the sheet is made of a flame-retardant material . the connection portion includes a pair of branch connection tubes to which the power cables are connected in parallel,
3. The power cable connection work cover according to claim 1 , wherein the sheet has a pair of side surfaces on which the slits are formed .