Power cable connection part cover

Abstract

To provide a power cable connection part cover which can be safely used outdoors with a reduced production cost.SOLUTION: A power cable connection part cover 1a includes a polycarbonate cover body 2 that is formed of a first half split body 4 and a second half split body 5 coupled in an openable / closable manner via a shaft rod 6 and is attached to a power cable connection part, and a temperature indicating material 3 that is formed of a sheet-like temperature detection material whose color changes when a specific temperature is reached, and is set inside the cover body 2. On outer surfaces 4c, 5c at free ends 4a, 5a of the first half split body 4 and the second half split body 5, projections 7, 8 are respectively disposed in an engageable manner.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a cover installed at a connection point of a power cable, and more particularly to a power cable connection cover capable of detecting the presence or absence of heat generation due to poor contact at that point. [Background technology]

[0002] A porcelain tube and a rubber stress cone are attached to the end of a power cable that is connected to a SOG (high voltage AC air load breaker) installed on a utility pole. The structure of the end of a power cable that is connected to an SOG will now be explained using Figure 5. Figure 5 shows an example of the appearance of the end of a power cable. As shown in FIG. 5, a power cable 50 has a stripped end (not shown) fitted with a rubber stress cone 51 and a porcelain insulator tube 52, which has a cap 53 attached to its tip and is filled with an insulating compound. The conductor end (not shown) of the power cable 50 is fixed to a terminal 54 integrally molded with the cap 53. A protective layer 55 is formed on the end of the rubber stress cone 51 using adhesive polyethylene insulating tape or self-adhesive insulating tape wrapped around a portion of the power cable 50. A main mounting bracket 56 is attached to the rubber stress cone 51 above the protective layer 55, and a grounding wire 57 made of tin-plated annealed copper wire extends from below the protective layer 55. The three power cables 50 are bundled together by a cable bracket 58 attached below the rubber stress cone 51.

[0003] If there is poor contact in the part where the power cable 50 is connected (hereinafter referred to as the power cable connection part), heat will be generated in that part, causing melting of the conductor connection point and burning of the surrounding insulator, which may ultimately lead to a ground fault. Therefore, in the past, the presence or absence of heat generation in the above part has been confirmed using a thermotracer or the like. However, this method requires the time and effort of carrying, setting up, and operating the thermotracer, making it difficult to efficiently locate the hot spot due to poor contact in a short amount of time.

[0004] Regarding technology for detecting heat-generating areas due to poor contact, for example, Patent Document 1 discloses an idea for a plug called "Plug for Air Conditioners, etc." that can prevent smoke or fire caused by poor electrical contact in devices that carry relatively large currents, such as air conditioners. The device disclosed in Patent Document 1, explained using the symbols shown in the drawings, is characterized in that a thermolabel (registered trademark) that changes color at approximately 45°C is attached to the center of the outer surface of the attachment plug body 1 as a temperature indicator 4. With this structure, even if the outlet into which the air conditioner's attachment plug body 1 is inserted is installed in a location that is difficult for the user of the air conditioner to reach, such as near the ceiling, the operator can quickly and efficiently discover that the part in question is generating heat by visually checking the discoloration of the temperature indicator 4.

[0005] Furthermore, Patent Document 2, entitled "Power cable connection structure and temperature detection unit and temperature sensing device used therein," discloses an idea for a device that detects abnormal heat generation at power cable connections, such as underground distribution lines, to prevent ground faults and fires. The device disclosed in Patent Document 2, explained using the symbols shown in the drawings, has a structure in which a power cable 1 is connected to an electrical device 3 such as a switch or a transformer via connectors 2, 2, 2 that form the power cable connection section, and temperature detection sections 4, 4a are attached to the connectors 2, 2, 2. As the ambient temperature of the power cable connection section rises, a temperature-sensitive element melts to cut off the circuit. With this structure, it is possible to remotely monitor abnormal heat generation at the connection portion of the power cable at low cost.

[0006] Furthermore, Patent Document 3 discloses a device for detecting abnormal heat generation in a conductor in an electrical device, entitled "Device for detecting abnormal heat generation in a conductor." The device disclosed in Patent Document 3, explained using the symbols shown in the drawings, comprises a voltage detector that generates an electromotive force corresponding to the voltage at the position opposite the detection electrode 6 through electrostatic induction and outputs an alarm signal, a shape memory alloy 4 attached to the part of the conductor 1 that is to be monitored for abnormal heat generation, and a movable electrode 5 attached to the shape memory alloy 4 and electrically connected to the conductor 1, and is characterized in that when the shape memory alloy 4 exceeds a temperature corresponding to abnormal heat generation in the conductor 1, it deforms and causes the movable electrode 5 to deform to the position opposite the detection electrode 6. With this structure, the shape memory alloy 4 is deformed by abnormal heating of the conductor 1, causing the movable electrode 5 to displace to a position opposite the voltage detection device, thereby outputting an alarm, eliminating the need for visual observation by humans. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Utility Model Application Publication No. 60-134282 [Patent Document 2] Japanese Utility Model Application Publication No. 6-60249 [Patent Document 3] Japanese Utility Model Application Publication No. 4-15030 Summary of the Invention [Problem to be solved by the invention]

[0008] The device disclosed in Patent Document 1 has a structure in which a thermo label is affixed to the outer surface of the attachment plug body 1, so there is a risk that the thermo label will get wet in the rain and peel off if used outdoors. The device disclosed in Patent Document 2 has a temperature detection unit 4 configured with a circuit having a thermosensitive element, so there is a risk that it will be exposed to rainwater or the like and cause a short circuit if used outdoors. Furthermore, the device disclosed in Patent Document 2 has the problem that it is time-consuming to install the temperature detection unit 4 at the power cable connection point, and also has the problem of high manufacturing costs. Furthermore, the device disclosed in Patent Document 3 has the problem that it cannot be manufactured inexpensively because the mechanism for detecting abnormal heat generation is complex.

[0009] The present invention has been made in response to the above-mentioned conventional circumstances, and has as its object to provide a power cable connection cover that can be manufactured at low cost and can be used safely outdoors. [Means for solving the problem]

[0010] In order to achieve the above object, a first invention is a power cable connection cover that is installed at a connection point of a power cable, and is characterized in that it comprises a temperature indicating material installed on the surface of the connection point, and a cover main body that is installed at the connection point so as to cover the temperature indicating material, and at least a portion of the cover main body is formed from a transparent member that allows the temperature indicating material to be seen. In the first invention having such a structure, the temperature indicating material installed on the surface of the connection point of the power cable is covered by the cover body and is not exposed to wind and rain, which has the effect of making it less susceptible to deterioration. In addition, the first invention has the effect of reducing manufacturing costs due to its simple structure.

[0011] A second invention is characterized in that, in the first invention, the cover body is made up of a pair of half bodies connected via a shaft so as to be able to open and close freely. In the second invention, by closing the pair of half bodies with the power cable connection point sandwiched between them, it becomes easy to attach the cover body to the connection point, and by opening the pair of half bodies from that state, it becomes easy to remove the cover body from the connection point. That is, in addition to the effects of the first invention, the second invention has the effect of facilitating the work of attaching the cover body to the power cable connection point and removing the cover body from the connection point.

[0012] The third invention is characterized in that, in the second invention, the cover body has a window portion and is provided with a plate-shaped member formed of a transparent member that covers the temperature-indicating material and is installed within the cover body so as to be exposed from the window portion. In the third invention, the exposed portion of the plate-shaped member is small, and therefore, in addition to the effects of the second invention, the plate-shaped member is less likely to deteriorate. Also, since the cover body does not need to be transparent, there are more options for the material of the cover body.

[0013] The fourth invention is characterized in that, in the second or third invention, fixing means for maintaining the cover body in a closed state are provided on the outer surfaces of the pair of half bodies. In the fourth invention, the cover body is maintained in a closed state by the fixing means, and in addition to the effects of the second or third invention, it has the effect of preventing the cover body from accidentally opening when in a closed state.

[0014] The fifth invention is characterized in that, in the fourth invention, the pair of half bodies each have a protrusion at its free end, the fixing means is composed of a pair of magnets each built into the protrusion, and the pair of magnets are arranged so that they are close to or in contact with each other when the cover body is closed. In the fifth invention, in addition to the effect of the fourth invention, the pair of magnets stick together, thereby reliably maintaining the cover body in a closed state, and the cover body can be easily opened by separating the pair of stuck magnets.

[0015] A sixth invention is characterized in that in any one of the first to third inventions, the transparent member is made of polycarbonate. Polycarbonate has better weather resistance than acrylic, is cheaper in material cost than glass, and is easy to mold. Therefore, in addition to the effects of any one of the first to third inventions, the sixth invention has the effect that the transparent member is less likely to deteriorate and its manufacturing cost is low. [Effects of the Invention]

[0016] According to the first invention, the temperature indicating material is not exposed to wind and rain and is not easily deteriorated, so it can be used safely outdoors. In addition, the first invention can be manufactured inexpensively.

[0017] According to the second invention, since the cover body can be easily attached and detached to and from the power cable connection portion, in addition to the effect of the first invention, the work of removing the cover body and replacing the temperature indicator when the expiration date of the temperature indicator has passed can be performed efficiently in a short time. Similarly, when the cover body deteriorates, the cover body can be easily removed from the installation location and replaced efficiently.

[0018] According to the third invention, the plate-shaped member is less likely to deteriorate, and by using a member for the cover body that is more weather-resistant than the plate-shaped member, the cover body is even less likely to deteriorate than the plate-shaped member, thereby achieving the effect of being able to be used safely for a long period of time in addition to the effect of the second invention.

[0019] According to the fourth invention, if the cover body is opened accidentally when closed, the temperature indicator will not be exposed to wind and rain, which will accelerate its deterioration, and the cover body will not come off and fall from its installation location, so in addition to the effects of the second or third invention, it has the effect of being safe to use.

[0020] In the fifth invention, the function of facilitating opening and closing of the cover body while maintaining the closed state of the cover body is achieved with a simple structure, thereby achieving the effect of reducing manufacturing costs in addition to the effect of the fourth invention.

[0021] In the sixth invention, the transparent member is resistant to deterioration and is inexpensive to manufacture, and therefore, in addition to achieving the effects of any one of the first to third inventions, the effects of being able to be used for a long period of time and being inexpensive to manufacture are further achieved. [Brief explanation of the drawings]

[0022] [Figure 1] FIG. 1(a) is a front view of a power cable connection portion cover according to a first embodiment of the present invention, and FIG. 1(b) is a view taken in the direction of an arrow A in FIG. [Figure 2] 1(a) and 1(b) are views showing the first half and the second half of FIG. 1(a) and FIG. 1(b) in an open state, respectively. [Figure 3] 2 is an external view showing the power cable connection portion cover shown in FIG. 1 actually installed on the power cable connection portion. FIG. [Figure 4] FIG. 1(a) is a front view of Example 2 of a power cable connection portion cover according to an embodiment of the present invention, and FIG. 1(b) is a cross-sectional view taken along line BB in FIG. 1(a). [Figure 5] FIG. 1 is a diagram showing an example of the appearance of a terminal end of a power cable. DETAILED DESCRIPTION OF THE INVENTION

[0023] The structure, operation, and effects of the power cable connection cover according to the embodiment of the present invention will be specifically described with reference to FIGS. [Example]

[0024] Fig. 1(a) is a front view of a power cable connection cover 1 according to an embodiment of the present invention, and Fig. 1(b) is a view seen in the direction of arrow A in Fig. 1(a). Figs. 2(a) and 2(b) are views showing the first half body 4 and the second half body 5 in Fig. 1(a) and Fig. 1(b), respectively, when opened. Fig. 3 is an external view showing the power cable connection cover 1a shown in Fig. 1 actually installed at the connection portion of a power cable 50. In addition, in Figure 1(a), a part of the location where the power cable connection cover 1a is installed (protective layer 55 shown in Figure 5) is shown by a dashed line, in Figure 2(a) the protective layer 55 is not shown, and in Figures 1(b) and 2(b) the protective layer 55 and the temperature indicating material 3 are not shown.

[0025] As shown in Figures 1(a) and 1(b) and Figures 2(a) and 2(b), the power cable connection cover 1a is made up of a first half body 4 and a second half body 5 connected via an axial rod 6, and is equipped with a temperature indicator 3 to be installed at the connection point of the power cable 50 as already explained using Figure 5, and a cover main body 2 to be installed at the connection point of the power cable 50 so as to cover this temperature indicator 3. The first half body 4 and the second half body 5 are formed from a transparent synthetic resin such as polycarbonate so that the temperature indicator 3 placed inside can be seen from the outside, but the shaft rod 6 does not need to be transparent, so it is also possible to use a synthetic resin with high sliding properties such as nylon or polyacetal.

[0026] On the outer surfaces 4c, 5c of the ends 4b, 5b on the side where the first half-body 4 and the second half-body 5 are connected to each other, bearings 6a, 6b, through which the shaft 6 is communicated, are provided so that their axes coincide with each other and they can be arranged so as to alternately mesh with each other. In other words, the first half-body 4 and the second half-body 5 are swingably connected via the shaft 6 that is communicated with the bearings 6a, 6b, and can be opened and closed by swinging them around the shaft 6. The free ends 4a, 5a of the first half-body 4 and the second half-body 5 are provided on their outer surfaces 4c, 5c with protrusions 7, 8, respectively, so that the protrusions 7a, 8a can engage with the protrusions 7a, 8a when the cover body 2 is closed. The protrusion 7a has a hook-like shape that can engage with the protrusion 8a. That is, when the first half-body 4 and the second half-body 5 are closed, the protrusion 7a of the protrusion 7 engages with the protrusion 8a of the protrusion 8, preventing the first half-body 4 and the second half-body 5 from accidentally opening. When a predetermined force is applied to the first half-body 4 and the second half-body 5 so that the protrusion 7 elastically deforms, the protrusion 7a of the protrusion 7 is easily disengaged from the protrusion 8a of the protrusion 8. That is, the protrusions 7, 8 constitute a fixing means for maintaining the cover body 2 in a closed state.

[0027] The temperature indicator 3 is a sheet-like temperature detection material that changes color at a specific temperature, and is configured so that the presence or absence of heat generation can be visually confirmed by the color change. In the case of a power cable connection part as shown in Fig. 5, the heat resistance temperature of the insulating tape used to form the protective layer 55 is about 60°C, so for example, Thermo Label (registered trademark) manufactured by Nihon Yu Giken Kogyo Co., Ltd., which has a reaction temperature range of 50°C to 120°C, can be used. However, the temperature indicator 3 is not limited to this and can be changed as appropriate depending on the installation location and usage conditions.

[0028] The power cable connection cover 1a having this structure can be easily attached to the protective layer 55, which is the connection location, as shown in FIG. 3 by opening the cover body 2 so that the connection location of the power cable 50 is sandwiched between the first half body 4 and the second half body 5, and then closing the cover body 2. Furthermore, by opening the first half body 4 and the second half body 5 from this state, the cover body 2 can be easily removed from the connection location. Generally, the thermolabel used as the temperature indicator 3 in the power cable connection cover 1a has a shelf life of about two years. However, with the power cable connection cover 1a, the cover body 2 can be easily attached to and removed from the connection location of the power cable 50, allowing for quick and efficient replacement of expired thermolabels and deteriorated cover bodies 2.

[0029] The power cable connection cover 1a has the temperature indicating material 3 placed on the surface of the connection point (protective layer 55) of the power cable 50 covered by the cover body 2, is not exposed to wind and rain, and is resistant to deterioration, so it can be used safely outdoors. Furthermore, the power cable connection cover 1a has a simple structure and low manufacturing costs, so it can be manufactured inexpensively. Furthermore, in the power cable connection cover 1a, the protrusions 7 and 8 function as fixing means for maintaining the closed state of the cover body 2, so that the temperature indicating material 3 is not exposed to wind and rain when the closed cover body 2 is accidentally opened, which would accelerate deterioration of the temperature indicating material 3 and prevent the cover body 2 from falling off from its installation location. Therefore, the power cable connection cover 1a can be used safely. [Example]

[0030] Fig. 4(a) is a front view of a power cable connection cover 1b according to an embodiment of the present invention, and corresponds to Fig. 1(a) showing the power cable connection cover 1a. Fig. 4(b) is a cross-sectional view taken along line BB in Fig. 4(a). In Fig. 4(a), a part of the location where the power cable connection portion cover 1b is installed (the location surrounded by the dashed line in Fig. 3) is indicated by a dashed line, and in Fig. 4(b), the protective layer 55, the temperature indicating material 3, the plate-like member 9, and the magnet 10 are not shown. In addition, the components shown in Figs. 1 to 3 are denoted by the same reference numerals, and their explanations will be omitted as appropriate.

[0031] As shown in Figures 4(a) and 4(b), the power cable connection cover 1b is characterized in that the power cable connection cover 1a is equipped with a transparent plate-like member 9 made of polycarbonate, which is a rectangular plate curved in an approximately arc shape, and a pair of rectangular plate-like magnets 10, 10. A recess 9a is provided on the inner surface 4d of the first half-body 4, and a plate-like member 9 is fitted into this recess 9a. A window 9b is provided on the outer surface 4c of the first half-body 4 so as to communicate with the recess 9a. Note that the window 9b is formed to a size that prevents the plate-like member 9 from passing through, so there is no risk that the plate-like member 9 fitted into the recess 9a will pass through the window 9b and fall out of the first half-body 4. Furthermore, recesses 10a are provided on the protrusions 7, 8 at locations that face each other when the cover body 2 is closed, and magnets 10 are fixedly attached to the pair of recesses 10a, 10a. The pair of magnets 10, 10 are arranged so that they are close to or in contact with each other when the cover body 2 is closed. As will be described later, in the power cable connection cover 1b, the pair of magnets 10, 10 form a fixing means for maintaining the cover body 2 in the closed state.

[0032] In the power cable connection part cover 1b having such a structure, the exposed portion of the plate-shaped member 9 is small, and the plate-shaped member 9 is less likely to deteriorate, allowing for long-term safe use. In addition, since the cover main body 2 does not need to be transparent, the life of the cover main body 2 can be extended by using a material that is more weather-resistant than the plate-shaped member 9 for the cover main body 2. This further enhances the aforementioned effect of long-term safe use. Furthermore, in the power cable connection cover 1b, the pair of magnets 10, 10 built into the protrusions 7, 8 stick together, thereby reliably maintaining the cover body 2 in a closed state. The cover body 2 can then be easily opened by separating the pair of stuck magnets 10, 10. In other words, in the power cable connection cover 1b, the function of maintaining the cover body 2 in a closed state while facilitating opening and closing of the cover body 2 is achieved by the simple structure of the pair of magnets 10, 10, and therefore manufacturing costs can be reduced.

[0033] The power cable connection cover of the present invention is not limited to the structure described above for power cable connection covers 1a and 1b. For example, although the cover body 2b of power cable connection cover 1a and the plate-like member 9 of power cable connection cover 1b are made of polycarbonate, these members may be made of transparent synthetic resins other than polycarbonate, such as acrylic, or glass. However, polycarbonate has better weather resistance than acrylic, is less expensive than glass, and is easy to mold. Therefore, using polycarbonate for the above members offers the advantages of being less susceptible to deterioration and having low manufacturing costs. In addition, in the power cable connection cover 1b, the recess 9a and the window 9b are provided in the first half-body 4, but the recess 9a and the window 9b may be provided in the second half-body 5 instead of the first half-body 4. [Industrial Applicability]

[0034] The power cable connection cover of the present invention can be used when inspecting whether or not there is a poor connection at the point where the power cable is connected. [Explanation of symbols]

[0035] DESCRIPTION OF SYMBOLS 1a, 1b... Power cable connection cover 2... Cover body 3... Temperature indicating material 4... First half body 4a... Free end 4b... End part 4c... Outer surface 4d... Inner surface 5... Second half body 5a... Free end 5b... End part 5c... Outer surface 6... Shaft 6a, 6b... Bearing part 7, 8... Protruding part 7a, 8a... Tip 9... Plate-shaped member 9a... Recess 9b... Window part 10... Magnet 10a... Recess 50... Power cable 51... Rubber stress cone 52... Porcelain bushing 53... Cap 54... Terminal 55... Protective layer 56... Main body mounting bracket 57... Ground wire 58... Cable bracket

Claims

1. A power cable connection cover that is installed at a power cable connection point, A temperature indicating material placed on the surface of the connection portion; a cover body that is installed at the connection point so as to cover the temperature indicating material, The power cable connection cover is characterized in that at least a portion of the cover body is formed from a transparent material that allows the temperature indicating material to be visually recognized.

2. 2. The power cable connection cover according to claim 1, wherein the cover body is made up of a pair of half bodies connected to each other via a shaft so as to be able to open and close freely.

3. The cover body has a window portion, The power cable connection cover according to claim 2, further comprising a plate-shaped member formed of the transparent member, covering the temperature-indicating material, and installed within the cover body so as to be exposed from the window portion.

4. 4. The power cable connection cover according to claim 2, wherein fixing means for maintaining the cover body in a closed state are provided on outer surfaces of the pair of half bodies.

5. The pair of half bodies each have a protrusion at a free end, the fixing means is constituted by a pair of magnets respectively embedded in the protrusions, 5. The power cable connection cover according to claim 4, wherein the pair of magnets are arranged so as to be close to or in contact with each other when the cover body is closed.

6. 4. The power cable connection cover according to claim 1, wherein the transparent member is made of polycarbonate.

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