JP7033322B2 - Deterioration display device - Google Patents

Description

The present invention relates to a deterioration display device that detects and displays the degree of deterioration of the lightning protection device.

Conventionally, it has been known that an abnormal overvoltage and / or overcurrent is temporarily generated in an electric device, a power line, or a signal line due to a lightning strike. Such overvoltage and overcurrent are also called surge voltage and surge current, respectively, and the surge voltage and surge current are collectively called lightning surge. Since this lightning surge may cause damage, malfunction, failure, etc. to the electrical equipment, SPD (Surge Protective device), SPD (Surge Protective device), etc. on the power supply line, communication line, signal line, antenna line, etc. to protect the electrical equipment. A lightning protection device such as a lightning arrester is installed.

The lightning protection device includes one or more non-linear elements such as MOV (metal oxide varistor) and GDT (gas-filled discharge tube). A non-linear element has a resistance value as high as that of an insulator with respect to the voltage when a normal electric device is used, while the resistance value drops instantaneously with respect to an overvoltage of a lightning surge. When the resistance value of the non-linear element decreases during a lightning strike, the surge current flows to the ground through the lightning protection device, the surge voltage is suppressed, and the electrical equipment is protected.

However, the non-linear element of the lightning protection device deteriorates due to repeated lightning surges and lightning surges that greatly exceed the rating. When the lightning protection device deteriorates, the leakage current gradually increases, and eventually the non-linear element is destroyed by heat generation, and the lightning protection device fails. However, if the lightning protection device remains broken, the electrical equipment cannot be protected. The failed lightning protection device needs to be replaced immediately. However, since it is often not possible to visually recognize whether or not the non-linear element is deteriorated, a deterioration display device indicating the state of deterioration of the lightning protection device has been proposed.

For example, the device described in Patent Document 1 is provided on the ground wire of a power distribution material such as a lightning protection device, and a display unit is housed in a housing. The display unit is attached to the plunger of the self-holding solenoid, and when the distribution material is normal, the self-holding solenoid attracts the plunger by magnetic force to position the display unit in the upper non-display position. .. Leakage current flowing through the ground wire gradually increases due to deterioration of the distribution material, and when the leakage current exceeds a certain value, the leakage current generates a magnetic force that cancels the magnetic force that attracts and holds the plunger to the self-holding solenoid. The suction of the plunger is released. As a result, the display unit moves downward due to its own weight, and displays that the distribution material has deteriorated.

Japanese Unexamined Patent Publication No. 2013-229162

However, in the apparatus described in Patent Document 1, since the display of the display unit is switched depending on whether the leakage current flowing through the ground wire exceeds a certain value due to the deterioration of the electric power distribution material, whether the electric power distribution material is normal or deteriorated. There is a problem that only one of them can be displayed, and the degree of deterioration cannot be displayed to the extent of deterioration.

The present invention has been made focusing on the above-mentioned problems, and an object of the present invention is to provide a deterioration display device capable of displaying the degree of deterioration of the lightning protection device.

The deterioration display device according to the present invention displays the degree of deterioration of the lightning protection device, detects the degree of deterioration of the display body and the lightning protection device, and corresponds to the degree of deterioration of the detected lightning protection device. It is provided with a detection drive mechanism that displaces the display body. The detection drive mechanism is connected to a grounding wire that grounds the lightning protection device, and is in contact with a heat-generating resistor that generates heat due to a surge current flowing during a lightning strike and the heat-generating resistor, and is thermally deformed by the heat generated by the heat-generating resistor. A detection body made of a thermoplastic resin is provided, and the display body is interlocked with the thermal deformation of the detection body.

The heat generation resistor of the deterioration display device of the present invention is connected to the ground wire of the lightning protection device, and the surge current flowing through the lightning protection device due to a lightning strike flows to the ground through the heat generation resistor. When the heat-generating resistor generates heat due to the surge current, the heat-generating resistor thermally deforms the portion of the detector in contact with the heat-generating resistor, and the display body is displaced by this thermal deformation. Each time a surge current flows through the heat-generating resistor due to a lightning strike, the heat-generating resistor thermally deforms the detector and displaces the display. In this way, the energy received by the non-linear element of the lightning protection device from the lightning surge is detected as the amount of deformation of the detection body, and the display body is displaced according to the amount of deformation of the detection body. Since the lightning protection device deteriorates as the total amount of energy received by the lightning surge increases, the degree of deterioration of the lightning protection device can be expressed by the displacement amount of the display body.

In a preferred embodiment, the detection drive mechanism moves the detection body relative to the heat generation resistor in response to thermal deformation of the detection body so as to maintain contact between the heat generation resistor and the detection body. Further provided with a driving means for driving.

In a preferred embodiment, a housing for accommodating the detection drive mechanism and the display body is further provided, the display body has a surface with a display indicating the degree of deterioration, and the housing has the display. A display window is provided at a position corresponding to the surface of the body so that at least a part of the surface can be visually recognized.

In the above embodiment, the driving means may be the heat generation resistor or the elastic body that urges the detector.

The heat generation resistor may be a conductor wire connected in series with the ground wire and bent in a U-shape or a V-shape.

A switch member for detecting that the deterioration of the lightning protection device has reached a predetermined degree may be further provided.

According to the present invention, the degree of deterioration of the lightning protection device can be displayed.

It is a schematic plan view for demonstrating the principle of the deterioration display device which concerns on one Embodiment of this invention, (A) is a figure at the time of the initial state of a lightning protection device, (B) is a state in which a lightning protection device is in the process of deterioration. The figure at the time of (C) is a figure at the time when the lightning protection device is in a deteriorated state. It is a perspective view which shows the whole structure of the lightning protection device for LAN cables including the deterioration display device which concerns on one Embodiment of this invention. It is an exploded perspective view of the deterioration display device. It is an exploded perspective view of a connecting member and a cover. It is an exploded perspective view of a connecting member and a cover. It is sectional drawing of the deterioration display device along the line AA of FIG. It is a figure which shows the deterioration display device in the initial state of a lightning protection device, (A) is a plan view of a part, (B) is a sectional view of a part, (C) is a side view of a display window of a housing. It is a figure which shows the deterioration display device when the lightning protection device is in the process of deterioration, (A) is a plan view of a part, (B) is a sectional view of a part, (C) is a side view of a display window of a housing. .. It is a figure which shows the deterioration display device when the lightning protection device is in a deteriorated state, (A) is a plan view of a part, (B) is a sectional view of a part, (C) is a side view of a display window of a housing. It is a circuit diagram explaining the whole structure of the lightning protection device for LAN cable including the deterioration display device. (A), (B), and (C) are explanatory views showing another example of the display body of the deterioration display device. It is a schematic plan view of a part which shows another example of a deterioration display device.

The deterioration display device 10 according to the embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 10, a lightning protection device 2 such as an SPD (Surge Protective device) and a lightning arrester is connected to the electric device 1, and the deterioration display device 10 of the present invention is connected to a ground wire 3 for grounding the lightning protection device 2. Is provided.

First, the principle of the deterioration display device 10 of the present invention will be described with reference to FIG. The deterioration display device 10 displays the degree of deterioration of the lightning protection device 2, detects the degree of deterioration of the display body 12 and the lightning protection device 2, and corresponds to the degree of deterioration of the detected lightning protection device 2. It is provided with a detection drive mechanism 14 that displaces the display body 12.

The detection drive mechanism 14 is connected in series with the ground wire 3 that grounds the lightning protection device 2, and is in contact with the heat generation resistor 15 that generates heat due to the surge current flowing during a lightning strike, and the heat generation resistor 15 generates heat. The detector 13 is made of a thermoplastic resin that is thermally deformed by the above, and the detector 13 is subjected to the thermal deformation of the detector 13 with respect to the exothermic resistor 15 so as to maintain the contact between the heat generating resistor 15 and the detection body 13. A driving means for relative movement and a connecting member 20 for connecting the detection body 13 and the display body 12 are provided, and the display body 12 is interlocked with the thermal deformation of the detection body 13. In the embodiment shown in FIG. 1, the driving means is a spring 16 which is an elastic body that urges the detection body 13 toward the heat generation resistor 15.

In the following description, a state in which the lightning protection device 2 is not deteriorated by a lightning surge, such as immediately after the lightning protection device 2 is replaced, is referred to as an "initial state", and the total amount of energy specified in advance by the lightning protection device 2 is defined as a state in which the lightning protection device 2 is not deteriorated. A state in which a lightning surge is received beyond the above and deteriorated to the extent that it needs to be replaced is called a "deteriorated state", and a state in which the degree of deterioration is between the "initial state" and the "deteriorated state" is the "deteriorated state". That is. Further, the direction in which the display body 12 is displaced is referred to as a "displacement direction", and the display body 12 is a lightning protection device from a first position P1 (FIG. 1 (A)) in which the lightning protection device 2 is located in the initial state. The direction from the first position P1 to the second position P2, which is displaced to the second position P2 (FIG. 1 (C)) in which 2 is in the deteriorated state, is also referred to as the tip side or the front side, and is the tip side or the front side. The opposite side is also referred to as the rear end side or the rear side. Further, the position of the display body 12 when the lightning protection device 2 is in the process of deterioration is referred to as a third position P3 (FIG. 1 (B)), and is between the first position P1 and the second position P2. To position.

The heat generation resistor 15 is made of a V-shaped conductor, one end of which is connected to the ground wire 3 on the lightning protection device 2 side, and the other end of which is connected to the ground wire 3 on the ground side. In the embodiment of FIG. 1, the heat generation resistor 15 is supported and fixed to the housing 5 and the like, and does not displace.

By bending the heat generation resistor 15 into a V shape, the resistance value of the bent portion 15a becomes higher than that of the straight portions 15c and 15c of the V shape, and heat is easily generated at the bent portion 15a. The shape of the heat generation resistor 15 is not limited to a V shape as long as the detection body 13 made of a thermoplastic resin can be deformed by heat generation, and may be, for example, a U shape or a linear shape. A known heat-generating resistor 15 can be used as the heat-generating resistor 15, which is a conductive material having a predetermined resistance value and can generate heat when a surge current flows to thermally deform the thermoplastic resin. Anything that can be made is acceptable, and is composed of, for example, a single substance such as copper, phosphor bronze, beryllium copper, tungsten, molybdenum, or an alloy thereof, or a material such as a metal nitride such as titanium nitride or tungsten carbide, or a material such as a metal carbide.

The detection body 13 has a rectangular parallelepiped shape, and the end portion 13a on the tip end side of the detection body 13 abuts on the inner surface surface of the V-shaped bent portion 15a of the heat generation resistor 15. The end portion 13a on the tip end side has a tapered shape along the inner surface of the bent portion 15a of the heat generation resistor 15. The outer peripheral surface of the detector 13 is supported by the housing 5 so as to be freely movable in the length direction.

The thickness of the detection body 13 has a thickness larger than the thickness of the heat generation resistor 15. As for the length of the detection body 13, when the lightning protection device 2 is in a deteriorated state and the detection body 13 moves with respect to the heat generation resistor 15, the bent portion 15a of the heat generation resistor 15 becomes the detection body 13. The length is set so that it does not reach the rear end.

The thermoplastic resin is a resin that softens when it reaches the melting point, and is composed of, for example, polycarbonate, polyethylene, polypropylene, polyvinyl chloride, etc., and can be thermally deformed by contact with a heat generating resistor 15 that generates heat. For example, known thermoplastic resins can be used. The thermal deformation of the thermoplastic resin includes the fact that the thermoplastic resin softens from the solid state to change its morphology due to heat, and melts to change from the solid state to the liquid state.

The resistance value, material, thickness, length, material, size, etc. of the heat-generating resistor 15 are appropriately selected according to the estimated amount of the total amount of lightning surge energy received by the lightning protection device 2.

The display body 12 is connected to the detection body 13 by a connecting member 20. The display body 12 has a display surface 12a with a display indicating the degree of deterioration, and the display surface 12a is divided into two regions 12A and 12B with the central portion in the displacement direction as a boundary 12C and is different. It is painted in different colors. For example, in FIGS. 1A to 1C, the front end side region 12A of the display body 12 is painted blue, and the rear end side region 12B is painted red.

The spring 16 is, for example, a compression spring, one end of which is fixed to the housing 5 and the other end of which is attached to the rear end of the detector 13. As shown in FIGS. 1A to 1C, the detection body 13 moves with the thermal deformation due to the urging force of the spring 16, and the display body 12 connected to the detection body 13 is the detection body 13. It is displaced from the first position P1 to the second position P2 via the third position P3 according to the thermal deformation of. The other end of the spring 16 may be a tension spring attached to the front end of the detection body 13.

The deterioration display device 10 is housed in the housing 5. A display window 5a on which the display surface 12a can be visually recognized is opened in the housing 5 at a position facing the display surface 12a of the display body 12. The display window 5a is slightly smaller than the respective regions 12A and 12B of the display surface 12a, and when the display body 12 is at the first position P1, only the tip end side region 12A of the display surface 12a can be visually recognized from the display window 5a and displayed. When the body 12 is in the second position P2, only the rear end side region 12B of the display surface 12a can be visually recognized from the display window 5a. The display mechanism is configured by the display window 5a of the housing 5 and the display surface 12a of the display body 12.

Next, the operation of the deterioration display device 10 will be described.
When the lightning protection device 2 is in the initial state, the end portion 13a on the tip end side of the detection body 13 abuts on the heat generation resistor 15 and is locked, and the display body 12 is first placed against the urging force of the spring 16. It is located at the position P1 of (FIG. 1 (A)). At this time, only the tip side region 12A painted in blue out of the display surface 12a of the display body 12 is visually recognized from the display window 5a of the housing 5.

When the lightning protection device 2 receives a lightning surge, a surge current flows to the ground via the heat generation resistor 15 of the deterioration display device 10. At this time, the heat generation resistor 15 generates heat, and the end portion 13a on the tip end side of the detection body 13 in contact with the heat generation resistor 15 softens or melts and is thermally deformed. In response to this deformation, the detection body 13 is displaced forward due to the urging force of the spring 16, and the heat generation resistor 15 is sunk into the end portion 13a of the detection body 13 (FIG. 1 (B)). The detection body 13 is constantly pressed against the heat generation resistor 15 by the urging force of the spring 16, and every time the lightning protection device 2 receives a lightning surge, the heat generation resistor 15 generates heat due to the surge current and the detection body 13 is thermally deformed. Then, the detection body 13 is displaced to the front side by the urging force of the spring 16, and the heat generation resistor 15 is deeply sunk into the detection body 13.

When the display body 12 is at the third position P3 shown in FIG. 1 (B), the boundary 12C between the regions 12A and 12B of the display surface 12a of the display body 12 is visually recognized from the display window 5a of the housing 5. It is shown that the closer the boundary 12C is to the tip side, the higher the degree of deterioration of the lightning protection device 2. By checking the display surface 12a from the display window 5a, the operator can know the degree of deterioration of the lightning protection device 2. Since the lightning protection device 2 deteriorates according to the total amount of energy received by the non-linear element 8 from the lightning surge, the amount of this energy is detected as the amount of deformation of the detection body 13 due to the heat generated by the heat generation resistor 15, and the detection body is detected. By displacing the display body 12 according to the amount of deformation of 13, the deterioration display device 10 displays the degree of deterioration of the lightning protection device 2.

Every time a lightning strike is repeated, a surge current flows through the heat generation resistor 15, and the lightning protection device 2 deteriorates. In the deteriorated state of the lightning protection device 2, as shown in FIG. 1C, the heat generation resistor 15 sinks into the vicinity of the rear end portion of the detection body 13, and the display body 12 reaches the second position P2. At this time, only the rear end side region 12B of the display surface 12a of the display body 12 is visually recognized from the display window 5a of the housing 5, and the operator can know that the lightning protection device 2 needs to be replaced.

According to the present embodiment, the energy received by the non-linear element 8 of the lightning protection device 2 from the lightning surge is detected as the amount of deformation of the detector 13 due to the heat generated by the heat generation resistor 15, and the display body is displayed as the amount of deformation of the detector 13. Since the 12 is interlocked, the degree of deterioration of the lightning protection device 2 can be expressed by the amount of displacement of the display body 12.

Further, the deterioration of the non-linear element 8 of the lightning protection device 2 is detected by using the heat generation resistor 15 that generates heat due to the surge current and the detector 13 made of the thermoplastic resin, and the urging force of the spring 16 that is the driving means is used. Since the display body 12 is displaced, it is not necessary to provide a power supply to the deterioration display device 10 in order to detect the deterioration of the lightning protection device 2 and display the degree of deterioration.

In the present embodiment, since the spring 16 is provided as a driving means for moving the detection body 13 relative to the heat generation resistor 15 according to the thermal deformation of the detection body 13, a surge current further flows through the heat generation resistor 15. Even if the detection body 13 is thermally deformed, the contact between the heat generation resistor 15 and the detection body 13 is maintained, the detection body 13 is reliably thermally deformed, and the degree of deterioration is detected by the heat generation resistor 15 and the detection body 13. can do.

Further, since the connecting member 20 for connecting the detection body 13 or the heat generation resistor 15 and the display body 12 is provided, the display body 12 is interlocked with the deformation of the detection body 13.

Further, since the surface 12a with the display indicating the degree of deterioration of the display body 12 can be visually recognized from the display window 5a of the housing 5, the operator can easily visually recognize the degree of deterioration of the lightning protection device 2.

Further, the heat generation resistor 15 is composed of a V-shaped or U-shaped bent conductor wire connected in series with the ground wire 3, and the resistance value of the bent portion 15a of the conductor wire is higher than the resistance value of the straight line portions 15c and 15c. Therefore, the calorific value of the bent portion 15a is larger than the calorific value of the straight portions 15c and 15c. The detection body 13 can be reliably thermally deformed by providing the bending portion 15a and increasing the amount of heat generated in the bending portion 15a, instead of uniformly generating heat of the entire heat generation resistor 15.

The spring 16 may be an elastic body that urges the heat generation resistor 15 toward the detection body 13. In this case, the spring 16 is attached to the heat generation resistor 15, and the heat generation resistor 15 is the detection body 13. The detector 13 is fixedly supported by the housing 5 and does not move, while being movably supported by the housing 5 in the length direction of the housing 5. Further, a spring 16 may be attached to each of the heat generation resistor 15 and the detection body 13, and the heat generation resistor 15 and the detection body 13 may be urged toward each other. In this case, the detection body 13 and the heat generation resistor 15 are supported by the housing 5 so as to be movable in the length direction of the detection body 13.

Next, a specific configuration of the deterioration display device 10 will be described with reference to FIGS. 2 to 9. In the present embodiment, as an example, the electric device 1 is a personal computer, the lightning protection device 2 is connected to the LAN cable 1a connecting the personal computer and the server, and the deterioration display device of the present invention is connected to the ground wire 3 of the lightning protection device 2. The configuration in which 10 is provided is shown. In the present embodiment, the deterioration display device 10 is integrally assembled with the lightning protection device 2 in the housing 5 as a part of the lightning protection device 4 for a LAN cable, as shown in FIG.

The lightning protection device 4 for a LAN cable is a lightning protection device 4 having connectors 7A and 7B for connecting the LAN cable on the personal computer side and the LAN cable on the server side on the first printed circuit board 6 housed in the housing 5. It includes a non-linear element 8 such as a GDT (gas-filled discharge tube) constituting 2 and a deterioration display device 10. Wiring (not shown) is formed on the first printed circuit board 6 by etching or the like, and one end of the non-linear element 8 of the lightning protection device 2 is electrically connected to the connectors 7A and 7B by this wiring. The other end is electrically connected to the deterioration display device 10. Although a plurality of non-linear elements 8 are connected in parallel in FIG. 2, only one non-linear element 8 is shown in FIG.

As shown in FIGS. 2 and 3, the deterioration display device 10 detects the degree of deterioration of the display body 12 and the lightning protection device 2 on the second printed circuit board 11 provided on the first printed circuit board 6. The detection drive mechanism 14 that displaces the display body 12 according to the degree of deterioration of the detected lightning protection device 2 and the switch member 18 that detects that the deterioration of the lightning protection device 2 has reached a predetermined degree. It is provided. The detection drive mechanism 14 is connected to the ground wire 3 of the lightning protection device 2, comes into contact with the heat generation resistor 15 that generates heat due to the surge current flowing during a lightning strike, and the heat generation resistor 15, and is thermally deformed by the heat generation of the heat generation resistor 15. A spring 16 that moves the detection body 13 toward the heat generation resistor 15 according to the thermal deformation of the detection body 13 so as to maintain the contact between the detection body 13 made of thermoplastic resin and the heat generation resistor 15 and the detection body 13. And a connecting member 20 for connecting the display body 12 to the detection body 13, and the display body 12 is interlocked with the thermal deformation of the detection body 13.

As shown in FIG. 3, the heat generation resistor 15 is attached to the surface of the second printed circuit board 11 and is composed of a V-shaped conductor. The second printed circuit board 11 is formed with a through groove 11a elongated in the displacement direction. The heat generation resistor 15 is V so that the V-shaped bent portion 15a is located on the tip side of the through groove 11a from the center in the length direction (displacement direction) and the V-shaped opening faces the rear end side. Both ends 15b and 15b of the character shape are fixed to both sides of the through groove 11a of the second printed circuit board 11 by soldering. One end 15b of the heat generation resistor 15 is connected to the lightning protection device 2 via wiring (not shown) formed on the second printed circuit board 11 or wiring formed on the first printed circuit board 6. It is electrically connected to the non-linear element 8. The other end portion 15b of the heat generation resistor 15 is electrically connected to the grounding terminal 5g provided in the housing 5 via the wiring formed on the second printed circuit board 11.

A detection body 13 made of a thermoplastic resin supported by a connecting member 20 abuts on the inner side surface of the heat generation resistor 15 in a V shape. The detection body 13 has a rectangular parallelepiped shape along the through groove 11a in the length direction, and the end portion 13a on the distal end side has a tapered shape along the inner surface of the bent portion 15a of the heat generation resistor 15. As shown in FIGS. 6 and 7B, the detector 13 projects into the through groove 11a of the second printed circuit board 11.

The connecting member 20 connects the display body 12 and the detection body 13, and is arranged on the second printed circuit board 11 so as to be freely movable in the displacement direction. As shown in FIGS. 4 and 5, the connecting member 20 is orthogonal to the displacement portion 21 in which the detection body 13 is attached and the spring 16 for urging the connecting member 20 is accommodated, and the displacement portion 21 is orthogonal to the displacement direction. It is provided with a plate-shaped connecting portion 22 extending in the direction of the spring and having a display body 12 provided at the tip thereof.

The displacement portion 21 has a rectangular bottom wall 23 and side walls 24 projecting from both side edges of the bottom wall 23 in the width direction. As shown in FIG. 5, the detection body 13 is on the surface 23a of the bottom wall 23 facing the second printed circuit board 11, and the end portion 13a on the tip end side thereof is the heat generation resistor 15 in the initial state of the lightning protection device 2. It is attached to the position where it can be locked by adhesive or the like. The groove 25 formed by the bottom wall 23 and the side wall 24 is divided into two by a reinforcing rib 24a provided between the side walls 24, and a part of the spring 16 is provided in the groove 25A on the rear end side. Be housed. Further, the ridges 24b and 24b are formed on the outside of the upper end of each side wall 24, and the ridges 24b and 24b are slidably locked to the guide groove 33 (described later) provided in the cover 30. The movement of the connecting member 20 is guided.

One end of the connecting portion 22 is connected to the side wall 24 of the displacement portion 21, and the other end extends outward from the second printed circuit board 11 and the display body 12 is attached to the tip. As shown in FIG. 5, the surface 22a of the connecting portion 22 facing the second printed circuit board 11 is provided with reinforcing ribs 22b in the vertical and horizontal directions. The connecting portion 22 has a protruding portion 26 extending toward the tip end side in the displacement direction, and the tip of the protruding portion 26 turns on the switch member 18 when the lightning protection device 2 is in a deteriorated state. It is set to a length that allows it.

The display body 12 has a plate shape and is fixed to the tip of the connecting portion 22 of the connecting member 20 so that the display surface 12a faces the display window 5a of the housing 5. The display surface 12a has two regions 12A and 12B painted in different colors.

As shown in FIGS. 4 and 5, the cover 30 that covers the displacement portion 21 of the connecting member 20 and guides the displacement of the connecting member 20 has an upper wall 31 and a side wall 32 provided around the upper wall 31. is doing. The cover 30 is attached to the second printed circuit board 11 by having a plurality of locking projections 32a provided at the lower ends of the side wall 32 locked in the locking holes 11b provided in the second printed circuit board 11. .. As shown in FIGS. 5 and 6, ridges 33a and 33a are provided inside the upper wall 31 of the cover 30, and a guide groove 33 is formed between the ridges 33a and 33a and the upper wall 31. There is. As shown in FIG. 6, by freely sliding the protrusions 24b and 24b of the connecting member 20 into the guide groove 33, the connecting member 20 is assembled to the cover 30 and the movement of the connecting member 20 is guided. .. A rod-shaped member 34 projects from the inner surface of the side wall 32 on the rear end side of the cover 30 in the displacement direction, and the rod-shaped member 34 is passed through the hollow portion of the spring 16 to support the spring 16 and extend the spring 16. It guides the direction of contraction. In the state where the connecting member 20 is assembled to the cover 30, one end surface of the spring 16 comes into contact with the inner surface of the side wall 24 on the rear end side of the cover 30, and the other end surface is the groove 25A of the displacement portion 21 in which the spring 16 is housed. The connecting member 20 is in contact with the rib 24a of the above and is urged toward the tip end side in the displacement direction.

A switch member 18 is provided on the second printed circuit board 11 on the tip side of the connecting member 20. The switch member 18 is, for example, a micro switch in which a hinge lever type operation piece 18b is provided on a switch body 18a. The switch body 18a has a push button (not shown) operated by the operation piece 18b, and has an electric contact portion inside. When the push button is pushed down by the pushing pressure acting on the operation piece 18b, the electric contact portion is closed and the switch member 18 is turned on, and when the pushing pressure is released, the push button is restored to the protruding state. The electric contact portion is opened and the switch member 18 is turned off.

When the lightning protection device 2 is not in the deteriorated state and the display body 12 is in the first position P1 or the third position P3, the pressing force does not act on the operation piece 18b and the switch member 18 is in the off state (). 7 (A), 8 (A)). When the lightning protection device 2 is in a deteriorated state and the display body 12 reaches the second position P2, a pressing force is applied to the operation piece 18b by the protruding portion 26 of the connecting member 20, and the switch member 18 is turned on and turned on. A signal is output (FIG. 9 (A)). The switch member 18 is not limited to the micro switch of the present embodiment, and if the switch member 18 can be turned on when the lightning protection device 2 is in a deteriorated state and the display body 12 reaches the second position P2. Any form of switch member may be used, and a known switch member is used.

The switch member 18 is electrically connected to the signal line connector 19 provided on the second printed circuit board 11. By inserting a signal line connected to an external control device or the like into the signal line connector 19, it is possible to transmit to the outside that the lightning protection device 2 is in a deteriorated state.

A non-linear element 40 is electrically connected to the heat generation resistor 15 in parallel with the second printed circuit board 11. The non-linear element 40 is for allowing a surge current to flow to the ground when the heat generation resistor 15 is damaged and the wire is broken.

As shown in FIG. 2, the housing 5 includes a lower housing 5A and an upper housing 5B. As shown in FIG. 7C, the rectangular display window 5a provided in the housing 5 is formed by combining the opening 5b of the lower housing 5A and the opening 5b of the upper housing 5B. The side wall forming the display window 5a of the housing 5 is provided with an inclined portion 5c extending outward in the thickness direction, so that the operator can easily see the display surface 12a from an oblique direction with respect to the display window 5a. There is. Further, the upper housing 5B and the lower housing 5A are provided with openings 5e and 5e, respectively, and the openings 5e and 5e form a LAN cable window 5d for connecting the LAN cable terminal to the connectors 7A and 7B. Ru. The upper housing 5B is formed with a signal line window 5f for connecting a signal line terminal to the signal line connector 19.

Next, the operation of the deterioration display device 10 will be described. When the lightning protection device 2 is in the initial state, the end portion 13a on the distal end side of the detection body 13 is locked to the heat generation resistor 15, and the display body 12 is in the first position P1 (FIG. 7A). , FIG. 7 (B). At this time, only the tip side region 12A painted in blue on the surface of the display body 12 is visually recognized from the display window 5a of the housing 5 (FIG. 7 (C)).

When the lightning protection device 2 receives a lightning surge, a surge current flows to the ground via the heat generation resistor 15 of the deterioration display device 10, the heat generation resistor 15 generates heat, the detector 13 is thermally deformed, and the connecting member 20 Is displaced toward the tip side by the urging force of the spring 16, and the heat generation resistor 15 sinks into the detection body 13. Each time the lightning protection device 2 receives a lightning surge, the heat generation resistor 15 sinks into the detection body 13 according to the deformation of the detection body 13 (FIG. 8 (B)), and the display body 12 is displaced (FIG. 8 (FIG. 8). A)). That is, when the lightning protection device is in the process of deterioration, the display body 12 is at the third position P3, which is between the first position P1 and the second position P2, and the display body 12 is seen from the display window 5a of the housing 5. The boundary 12C between the front end side region 12A and the rear end side region 12B of the display surface 12a is visually recognized (FIG. 8C).

When the lightning protection device 2 is in a deteriorated state, the display body 12 reaches the second position P2 (FIGS. 9A and 9B), and the rear end side of the display body 12 is seen from the display window 5a of the housing 5. Only the area 12B is visually recognized (FIG. 9 (C)), and the operator can know that the lightning protection device 2 is in a deteriorated state and the lightning protection device 2 needs to be replaced. The protruding portion 26 of the connecting member 20 exerts a pressing force on the operation piece 18b of the switch member 18, and causes the switch member 18 to output an on signal. This on signal is sent to an external control device such as a personal computer (not shown) through a signal line connected to the signal line connector 19.

Further, when the lightning protection device 2 is not replaced immediately even if it is in a deteriorated state, the deterioration of the lightning protection device 2 further progresses, and the heat generation resistor 15 generates heat due to the leakage current or surge current from the lightning protection device 2. It may melt. In such a case, a surge current is passed through the non-linear element 40 connected in parallel with the heat generation resistor 15.

According to the present embodiment, the energy received by the non-linear element 8 of the lightning protection device 2 from the lightning surge is detected as the amount of deformation of the detector 13 due to the heat generated by the heat generation resistor 15, and the amount of deformation of the detector 13 is increased. Since the display body 12 is displaced, the degree of deterioration of the lightning protection device 2 can be expressed by the displacement amount of the display body 12. Further, the deterioration of the non-linear element 8 of the lightning protection device 2 is detected by using the heat generation resistor 15 that generates heat due to the surge current and the detection body 13 made of the thermoplastic resin, and the display body 12 is displayed by using the urging force of the spring 16. Since it is displaced, it is not necessary to provide a power supply to the deterioration display device 10 in order to detect the deterioration of the lightning protection device 2 and display the degree of deterioration.

Further, the second printed circuit board 11 is provided with the switch member 18, and in the present embodiment, the switch member 18 detects that the lightning protection device 2 has deteriorated. By providing the switch member 18, it is possible to detect not only the degree of deterioration of the lightning protection device 2 but also whether or not the lightning protection device 2 is in a deteriorated state.

Further, the present embodiment also has the same effect as that of the embodiment shown in FIG. That is, in the present embodiment, it is not necessary to provide a power supply to the deterioration display device 10 in order to detect the deterioration of the lightning protection device 2 and display the degree of deterioration. Further, the spring 16 can keep the heat generation resistor 15 in contact with the detection body 13, and the detection body 13 can be reliably thermally deformed. Further, since the connecting member 20 for connecting the detection body 13 and the display body 12 is provided, the display body 12 is interlocked with the deformation of the detection body 13. Further, since the display surface 12a of the display body 12 has the display window 5a of the housing 5 that can be visually recognized, the operator can easily visually recognize the degree of deterioration of the lightning protection device 2. Further, the heat generation resistor 15 is composed of a V-shaped or U-shaped bent conductor wire connected in series with the ground wire 3, and the amount of heat generated at the bent portion 15a is large, so that the detection body 13 is surely heated. It can be transformed.

Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

For example, in the deterioration display device 10 of the present embodiment, the heat generation resistor 15 is fixed to the second printed circuit board 11, the detection body 13 is fixed to the connecting member 20, and the detection body 13 moves with respect to the heat generation resistor 15. However, the detection body 13 may be fixed to the second printed circuit board 11, and the heat generation resistor 15 may be attached to the connecting member 20 to move.

Further, the display body 12 is not limited to the present embodiment, and may be any display body 12 as long as the operator can visually recognize the degree of deterioration of the lightning protection device 2. For example, as shown in FIG. 11A, the display surface 12a of the display body 12 gradually changes from a certain color (for example, white) toward another color (for example, black) from the rear end side to the front end side in the displacement direction. It may be painted to change. In this case, as the display body 12 is displaced, the color of the display surface 12a appearing on the display window 5a of the housing 5 changes, and the operator can visually recognize the degree of deterioration of the lightning protection device 2. Further, the display surface 12a of the display body 12 may be provided with a number or a symbol indicating the degree of deterioration. For example, in FIG. 11B, a number 12d whose value increases from the front end side to the rear end side in the displacement direction is attached. In this case, the display window 5a of the housing 5 is set to a size in which at least one of the numbers on the display surface 12a appears. As the display body 12 is displaced, the numerical value of the display surface 12a that can be visually recognized from the display window 5a changes, and the numerical value increases as the degree of deterioration increases. The operator can visually recognize the degree of deterioration of the lightning protection device 2 by the numerical value.

Further, the shape of the display body 12 is not limited to the rectangular plate. For example, as shown in FIG. 11C, it may be a needle-shaped rod or a triangular plate. In the example of FIG. 11C, a scale 5h indicating the degree of deterioration is attached to the upper side surface of the display window 5a of the housing 5, and the operator is protected by the position of the scale 5h indicated by the needle-shaped rod. The degree of deterioration of 2 can be visually recognized. In this case, the display body 12, the display window 5a, and the scale 5h form a display mechanism.

Further, in the present embodiment, the switch member 18 detects that the display body 12 is in the second position P2 and the lightning protection device 2 is in a deteriorated state, but the present invention is not limited to this, and for example, It may be detected that the switch member 18 is turned on when the lightning protection device 2 is out of the initial state, that is, when the display body 12 is separated from the first position P1.

For example, in the embodiment shown in FIG. 12, the switch member 18 is arranged on the rear end side of the connecting member 20, and the protruding portion 26 of the connecting member 20 extends toward the rear end side. In the switch member 18, the push button is pushed down by the push pressure acting on the operation piece 18b, the electric contact portion is opened, the switch member 18 is turned off, and the push button protrudes by releasing the push pressure. A device is used in which the electric contact portion is opened and the switch member 18 is turned on by recovering to the state.

In the initial state of the lightning protection device 2, as shown in FIG. 12, a pushing pressure is applied to the operation piece 18b of the switch member 18 by the protruding portion 26 of the connecting member 20, and the push button is pushed down, and the switch member 18 is pushed down. Is off. When the lightning protection device 2 begins to deteriorate and the connecting member 20 moves to the tip side, the pressing force acting on the operation piece 18b is released and the switch member 18 is turned on. As a result, the switch member 18 can detect that the lightning protection device 2 is no longer in the initial state.

Further, the switch member 18 may be configured to detect that the display body 12 is at the third position P3 and the lightning protection device 2 has reached a predetermined degree of deterioration.

Further, in the present embodiment, the spring 16 is provided as a driving means for displacing the display body 12, but if the display body 12 can be displaced by moving the detection body 16 relative to the heat generation resistor 15, the driving means can be used. It may have any configuration.

2 Lightning protection device 3 Ground wire 5 Housing 5a Display window 10 Deterioration display device 11 Second printed circuit board 12 Display body 12a Display surface 13 Detection body 14 Detection drive mechanism 15 Heat generation resistor 16 Spring (elastic body, drive means)
18 Switch member 20 Connecting member

Claims (6)

It is a deterioration display device that displays the degree of deterioration of the lightning protection device.
Display body and
It is provided with a detection drive mechanism that detects the degree of deterioration of the lightning protection device and displaces the display body according to the detected degree of deterioration of the lightning protection device.
The detection drive mechanism is
A heat-generating resistor that is connected to the grounding wire that grounds the lightning protection device and generates heat due to the surge current that flows during a lightning strike.
A detection body made of a thermoplastic resin that comes into contact with the heat generation resistor and is thermally deformed by the heat generation of the heat generation resistor is provided.
A deterioration display device that interlocks the display body with the thermal deformation of the detection body. The detection drive mechanism further provides a driving means for moving the detection body relative to the heat generation resistor in response to thermal deformation of the detection body so as to maintain contact between the heat generation resistor and the detection body. The deterioration display device according to claim 1. Further comprising a housing for accommodating the detection drive mechanism and the display body.
The display body has a surface with a display indicating the degree of deterioration.
The deterioration display device according to claim 1 or 2, wherein the housing is provided with a display window at a position corresponding to the surface of the display body so that at least a part of the surface can be visually recognized. The deterioration display device according to claim 2, wherein the driving means is an elastic body that urges the heat generation resistor or the detection body. The deterioration display device according to any one of claims 1 to 4, wherein the heat generation resistor is connected in series with the ground wire and is composed of a lead wire bent in a U-shape or a V-shape. The deterioration display device according to any one of claims 1 to 5, further comprising a switch member for detecting that the deterioration of the lightning protection device has reached a predetermined degree.

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