JPH027433B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION When an abnormal current flows in a power line such as a distribution line due to a line short circuit, a short circuit between phases, or other similar accidents, the present invention displays the section where the accident occurred, and also displays the accident state. This relates to an abnormal current display device for a power line that can cancel the fault display and return to the normal display after a certain period of time has passed after the fault is resolved and the power is restored.The purpose of the device is to have a simple structure and easy manufacture and assembly. An object of the present invention is to provide an abnormal current display device for a power line that can improve durability.

Hereinafter, an embodiment embodying the present invention will be described with reference to the drawings. In the drawing, 1 is a main body case integrally molded from rubber, and a cylindrical skirt portion 1a is integrally formed in the lower part of the main body case. 1
A thin wall portion 1b is formed at the intermediate outer circumferential portion of a, so that the lower half portion can be folded upward. 2,3
is an inverted U-shaped lid case that is removably attached to the upper surface 1c of the main body case 1 and is integrally molded with an insulating material such as weather-resistant rubber. A mounting bracket 4 having a female threaded portion 4a is embedded in each case so as not to come off when the cases 2 and 3 are molded. Reference numeral 5 denotes a connecting plate in the shape of a short rectangular cylinder with a lid fitted over the upper surfaces of both lid cases 2 and 3, and a screw 6 is screwed into the female threaded portion 4a of the mounting bracket 4 from the outside of the side wall of the connecting plate. The lid cases 2 and 3 are connected to each other so that each lid case 2 and 3 can rotate slightly around a screw 6 with respect to the connecting plate 5. Note that the outer surface of the connecting plate 5 is coated with an insulating layer (not shown) made of synthetic resin or the like.

Reference numeral 7 indicates an inverted U-shaped upper core piece 8 made of a magnetic material such as soft iron that is inserted when the lid case 2 is molded, and a U-shaped upper core piece 8 that is made of a magnetic material such as soft iron that is inserted when the main body case 1 is molded. This detection cut core is formed in an annular shape so as to surround the outside of the power line L when assembled with the lower core piece 9 having a shape. Reference numeral 10 denotes a first coil wound around the lower core piece 9, and together with the detection cut core 7 constitutes a detection current transformer 11.

Reference numeral 12 denotes an inverted U-shaped upper core piece 13 made of a magnetic material with high relative magnetic permeability, such as a silicon steel plate, which is inserted when the other lid case 3 is molded, and a U-shaped upper core piece 12 which is inserted when the main body case 1 is molded. The cut core for return is formed in an annular shape so as to surround the outside of the power line L in the assembled state with the letter-shaped lower core piece 14, and is configured to input power for return from the power line. Reference numeral 15 denotes a second coil wound around the lower core 14, which together with the cut core 12 for return constitutes a transformer 16 for return power.

The upper surface 1c of the main body case 1 is provided with a tapered annular groove 1f that becomes narrower toward the bottom along the outer edges of the four cut surfaces 9a, 14a of the lower core pieces 9, 14.
are respectively formed, and tapered annular protrusions 2a and 3a that are tightly fitted into the annular groove 1f are formed on the four lower end surfaces of the lid cases 2 and 3, respectively,
The close contact prevents rainwater from entering. or,
Silicone grease is applied to the annular groove 1f and the annular projections 2a, 3a to improve the rust prevention and watertightness of the end surfaces of the upper core pieces 8, 13 and the lower core pieces 9, 14.

17 is a head 17a when the main body case 1 is molded.
A pair of mounting bolts are inserted and fixed in an upward direction, and female threaded portions 17b are formed at their upper ends.By screwing together screws 18 from the upper surface of the connecting plate 5, The lid cases 2 and 3 are tightened and fixed between the upper surface of the main body case 1 and the connecting plate 5, and the cut cores 7 and 12 for detection and return are fixed.
The cut surfaces 8a, 13a, 9a, 14a of the upper core pieces 8, 13 and the lower core pieces 9, 14 are pressed into close contact with each other. Note that the screws 18 are designed not to come off from the upper surface of the connecting plate 5. Reference numeral 19 denotes a pair of retaining plates fixed to the lower surfaces of the heads 17a of the pair of mounting bolts 17 by screws 20, and engagement recesses 19a are formed on both sides of the plates, as shown in FIG. Four supports 21 formed approximately in a U-shape and made of an insulating material such as rubber are engaged with this locking recess, and the lower core piece 9,
By fitting the lower portions of both sides of the core pieces 9 and 14 together, the lower core pieces 9 and 14 are held parallel to each other at a constant interval when the main body case 1 is molded.

As shown in FIG. 2, a groove 22 is formed in the center of the upper surface 1c of the main body case 1 along an engagement groove 1d having an arcuate cross section and passing through the inside of the detection and return cut cores 7, 12. The lower clamping fitting for the engaged power line L has a clamping surface 22a having an arcuate cross section formed on its upper surface, and a pair of mounting bolts 17 on both sides of the central portion as shown in FIG.
A locking piece 22c provided with a hole 22b through which the
are integrally formed. Reference numeral 23 denotes a thick upper clamp fitting having almost the same shape as the lower clamp fitting 22, and clamping surfaces 23a and 23b having different radii of curvature are formed on the upper and lower surfaces thereof.
As shown in FIG. 7, on both sides of the central portion, there is a hole 23c into which one of the mounting bolts 17 can be loosely inserted, and a notch 2 into which the other mounting bolt 17 can be fitted from the side.
A locking piece 23e provided with 3d is integrally formed, and the upper and lower surfaces of the locking piece 23e on the side of the notch 23d prevent the washer 24 fitted to the mounting bolt 17 from moving in the horizontal direction. Locking protrusion 23f
is formed. Then, when the power line L is inserted between the clamp surfaces 23b and 22a of the upper and lower clamp fittings 23 and 22 constituting the clamp mechanism, and the upper clamp fitting 23 is pressed downward by the nut 25 screwed onto the mounting bolt 17, the power line L is inserted. L
is adapted to be held between both clamp fittings 22 and 23. In addition, the upper and lower clamp fittings 23,
Both end surfaces of the power line insertion direction of the power line 22 are curved toward the outside with respect to the power line to prevent the power line from being damaged by the clamp in the installed state.

Reference numeral 26 denotes a mounting frame that is removably housed in the skirt portion 1a of the main body case 1 as shown in FIG. It consists of first and second plates 28, 29 made of aluminum, third and fourth plates 30, 31 made of synthetic resin, and a mounting ring 32.
The mounting ring 32 is held at a constant distance by a spacer 33 fitted onto the bolt 27. Then, among the four bolts 27, a pair of bolts 27 that have passed through the first plate 28 are attached to the main body case 1.
A mounting tool 3 embedded and fixed to the inner top surface of the skirt portion 1a of the
4 to hold the mounting frame 26 within the skirt portion 1a.

Reference numeral 35 denotes a bottomed cylindrical protective case made of transparent synthetic resin formed to cover the entire mounting frame 26, and is secured by tightening to a nut 37 fixed to the mounting ring 32 with four screws 36. It is becoming more and more common.

By the way, the abnormal current display device according to the embodiment of the present invention can be roughly divided into an abnormal current detection section A that detects an abnormal current generated in the power line L, as shown in FIG.
A display drive section B that performs a display operation based on the abnormal current detected by the detection section A, a return power supply section H for introducing the steady current of the power line L, and a steady current of the power supply section H. and a display mechanism section J which is operated for display by the display drive section B and released from the display state to a steady state by the return drive section I. has been done.

First, the abnormal current table detection section A will be explained. This detection section is connected to the above-mentioned detection current transformer 11 and the first coil 10, and is fixed to the second plate 29 as shown in FIG. It is configured with a step-up transformer 38 (which may be omitted). 41a is a surge absorber connected in parallel to the secondary side of the step-up transformer 38.

As shown in FIG. 10a, the detection cut core 7 made of the magnetic material has a small magnetic permeability in a small magnetomotive force region where the relative value is 1 or less, and a large magnetomotive force where the relative value is greater than 1. It has a large magnetic permeability in the region. The material, shape, and dimensions of the detection cut core 7 are adjusted so that the relative value of the magnetomotive force due to the abnormal current becomes larger than 1 and the actual output is obtained in the transformer 11 only when a fault current flows. The windings are defined.

Display driver B includes a full-wave rectifier 39 connected to the transformer 38, a capacitor C connected to the DC side of the rectifier via a charging resistor R1, and a bidirectional trigger diode TD connected to the capacitor.
11, a driving coil 40 attached to the lower surface of the fourth plate 31, a discharging resistor R2 connected in parallel to the capacitor C, and a charging resistor R1 connected to the DC side of the rectifier 39.
, a variable resistor R3 for changing the voltage applied to the capacitor C, and a changeover switch S1 for adjusting the operating current fixed to the upper surface of the second plate 29 as shown in FIG. Then, when the terminal voltage of the capacitor C reaches a certain value, the trigger diode TD becomes conductive and the electric charge of the capacitor C is discharged by the drive coil 40. Further, the value of the discharging resistor R2 is set sufficiently larger than the value of the charging resistor R1, so that when the DC voltage of the rectifier 39 is maintained, the capacitor C is substantially charged through the charging resistor R1, and the DC voltage increases. After the charge has significantly decreased or disappeared, the charge in the capacitor C is discharged by the discharge resistor R2 within an appropriate time.

Further, in order to allow the changeover switch S1 to be operated externally, insertion holes 35a and 1e for an operating screwdriver (not shown) are formed in the protective case 35 and the skirt portion 1a of the main body case 1, as shown in FIG. A seal plug 1g is fitted into the insertion hole 1e.

The return power supply section H includes the above-mentioned return power supply transformer 1.
6, a surge absorber 41 connected in parallel to the second coil 15, a pair of Zener diodes ZD1 and ZD2 connected in opposite directions, and the surge absorber 41 and the Zener diode ZD.
In this embodiment, the surge absorber 41, the Zener diodes ZD1, ZD2, and the chiyoke coil 4 are connected between the surge absorber 41, the Zener diodes ZD1, ZD2, and
2 and 43 constitute an overvoltage absorption circuit Ha. The return cut core 12 itself made of a magnetic material has normal magnetization characteristics as shown in FIG.
The material, shape, size, and winding of the wire are specified.

As shown in FIG. 11, the pair of Zener diodes ZD1, ZD2 are connected to the first,
The Zener diodes are fixed to second plates 28 and 29, respectively, to reduce temperature rise due to heat generated by the Zener diodes themselves, thereby reducing thermal deterioration of the diodes. The reason why the chiyoke coils 42 and 43 are used is to protect the synchronous motor SM and the Zener diodes ZD1 and ZD2, which will be described later, from sudden surges occurring in the power line.

As shown in FIGS. 11 and 12, the return drive unit I includes a synchronous motor SM housed in a mounting case 44 fixed to the lower surface of the fourth plate 32.
and a changeover switch S2 similarly attached to the lower surface of the mounting case 44. When the movable contact 45 of the switch S2 is in contact with the fixed contact 46, the movable contact 45 itself is connected to the transformer 16 as a dummy resistor. When the movable contact 45 is switched to the fixed contact 47, the synchronous motor SM
is also connected to the transformer 16.

Next, the display mechanism section J will be explained.
48 is a drive gear fixed to the rotating shaft of the synchronous motor SM, 49 is a rotating shaft supported downward on the lower surface of the mounting case 44 so as to be parallel to the rotating axis of the gear, and 50 is the tip of the coaxial motor 49. This is a circular movable display plate for displaying normal conditions, which is fixed to a circular shape, and a notch 50a is made outward from the center of the plate, and both sides of the plate are spaced apart from each other in the axial direction of the rotation shaft 49. A gap G1 larger than the thickness of the fixed display board 51 to be described is formed, and the entire lower surface is colored, for example, black to form a normal display surface 50b.

Reference numeral 51 denotes a donut plate which supports the lower end exposed portions 27a of a pair of bolts 27 separated by 180 degrees among the four bolts 27 at two points on the outer periphery so as to be unrotatable in the circumferential direction and movable in the axial direction of the bolts 27. This is a fixed display board for accident display in the shape of a shape, with a notch 51a made outward from the center, and both sides of the board spaced apart from each other in the axial direction of the rotation shaft 49. A gap G2 larger than the thickness is formed so that the movable display plate 50 can advance and retreat to the lower surface of the fixed display plate 51 through this gap G2. The accident display surface 51b is colored, for example, red over approximately 350 degrees (the rest is the normal state display surface 5).
0a), and the accident state is notified by the difference in color from the movable display board 50.

Note that the entire lower surface of the fixed display board 51 may be colored, but in this case, the movable display board 50 can be
The normal state display cannot be performed unless the display boards 50 and 51 are rotated, and as a result, the notches 50a and 51a of both display boards 50 and 51 correspond to each other in the complete accident display position or the complete normal display position, and in this state, the movable display board 50 is fixed. Display board 5
In order to prevent this, it is necessary to wrap at least one of the notches 50a and 51a of both display plates 50 and 51.

Reference numeral 52 denotes a driven gear for deceleration that is fitted and fixed on the rotating shaft 49, and an operating piece 52a is integrally formed on one side of the gear as shown in FIG. 5
Reference numeral 3 denotes an L-shaped clutch lever rotatably supported by a support shaft 54 projecting downward from the lower surface of the mounting case 44, and a shaft 5 is attached to the bent portion of the clutch lever.
5, and clutch gears 56 and 57 are respectively fixed to the upper and lower ends of the coaxial shaft 55, and the upper clutch gear 56 is engaged with the drive gear 48, and the lower clutch gear 57 is engaged with the driven gear 52, respectively. . Note that a protrusion 53a integrally formed on the corner portion of the clutch lever 53 is engaged with the lower surface of the mounting case 44, so that the gears 56, 57
A stopper 58 is provided to maintain normal engagement between the two parts 48 and 52.

Reference numeral 59 denotes a movable display whose intermediate portion is wrapped around the rotating shaft 49, one end is wrapped around and locked to a protrusion 60 provided on the lower surface of the mounting case 44, and the other end is locked to a part of the driven gear 52. It is a storage spring for performing the display operation of the plate 50, and the part wrapped around the protrusion 60 is further extended and locked to the clutch lever 53, and this biasing spring part 59a is used to close the same lever 53.
The clutch gears 56 and 57 are biased clockwise around the support shaft 54 in FIG. Then, the synchronous motor SM is rotated in the direction of normal return, and the drive gear 48, clutch gear 56,
When the rotating shaft 49 is rotated in the same direction via the driven gear 57 and the driven gear 52, energy is stored.

Incidentally, the reduction ratio of the gear 48 and the gear 52 is set to such a value that the synchronous motor SM continues to rotate for, for example, three hours and the driven gear 52 gradually rotates about 350 degrees in the direction of returning to the normal state.

Reference numeral 61 denotes an L-shaped operating lever whose corner portion is rotatably supported on a shaft 63 relative to the mounting plate 62 of the drive coil 40. When the drive coil 40 is excited, the base end of the lever 61 is attracted and the shaft is rotated. 1st centering around 63
When the clutch lever 53 is rotated clockwise in FIG. 2, the tip of the clutch lever 53 is pushed against the elasticity of the urging spring portion 59a, so that the clutch gears 56 and 57 are separated from the driving and driven gears 48 and 52. There is.

64 is a support shaft 6 that is connected to the lower surface of the mounting case 44.
5 is a switch lever rotatably supported by the switch S2, the tip of which is locked to the movable contact 45 of the changeover switch S2, and the mounting case 44 and the lever 6
12, that is, in the direction in which the movable contact 44 is pressed into contact with the fixed contact 46 by a leaf spring 66 connected between the distal end of the movable contact 44 and the tip of the fixed contact 46. A projecting piece 64a is provided on one side of the switch lever 64 in correspondence with the rotation locus of the actuating piece 52a of the driven gear 52, and the switch lever 64 is actuated by the rotation of the movable display plate 50, and the changeover switch is activated. S
I am trying to operate 2. That is, when the normal display surface 50b of the movable display plate 50 is completely exposed as shown in FIG. Accident display surface 51 of display board 51
When b appears, the movable contact 45 and fixed contact 47 are closed.

Next, the operation of the abnormal current display device configured as described above will be explained.

Now, as shown in FIG. 15a, the protective case 35
When the normal state display surface 50b of the movable display board 50 is completely visible from the bottom surface and the energy storage spring 59 is in the state where the energy is stored to its maximum, an accident occurs in the power line L and an abnormally large current i is generated as shown by the solid line in FIG. When , this large current i becomes a magnetomotive force, and an output voltage e shown by a broken line in FIG. 16 is generated on the output side of the transformer 11 in accordance with the magnetization characteristic a in FIG. Due to the significant nonlinearity of the magnetization characteristic a, the ratio of the output voltages e′ and e in normal and abnormal conditions is much larger than the corresponding ratio of steady current i′ to abnormal current i, and as a result, in abnormal conditions The large output voltage e is converted into direct current by the rectifier 39 and charges the capacitor C.

When the voltage of the capacitor C reaches a predetermined value,
The trigger diode TD becomes conductive and the drive coil 40 is excited, thereby pushing the actuation lever 61 and the clutch lever 63 against the biasing spring portion 59a, and the clutch gears 56 and 57 are moved from the drive and driven gears 48 and 52. As a result, driven gear 5
2 and the movable display board 50 are moved in the display direction, that is, the accident display surface 5 of the fixed display board 51 by the stored force of the storage spring 59.
1b, and the entire accident display surface 51b of the fixed display board 51 is completely exposed, as shown in FIG.

At the same time as the accident display operation is completed, the actuating piece 52a of the driven gear 52 is switched to the protruding piece 64a of the switch lever 64.
, the movable contact 4 of the changeover switch S2
5 is switched from fixed contact 46 to 47. Note that in the state before switching, the commercial frequency component of the excessive voltage caused by the abnormal current is absorbed by the dummy resistor of the movable contact 45 itself, thereby preventing excessive voltage from being applied to the changeover switch S2. In addition, the peak voltage caused by the saturation of the reset cut core 12 is absorbed by the Zener diodes ZD1 and ZD2, and the steep surge caused by the accident is absorbed by the surge absorber 41, and the electrical insulation of the changeover switch S2 and related parts is Guaranteed.

Subsequently, when the switch or breaker installed in the power line L stops the abnormal current and the power line becomes in a state of no power for a while, the excitation of the drive coil 40 is released and the energy storage spring portion 59a is released. The clutch lever 53 returns due to the spring force, and the clutch gears 56, 57
are meshed with gear 48 and driven gear 52, respectively. When a steady current begins to flow through the power line L in this state, the synchronous motor is connected to the transformer 16 through the movable contact 45 and the fixed contact 47, which are already closed.
Power is supplied to the SM, and the rotation of this electric motor causes the movable display plate 50 to be
gradually moves back in the return direction while accumulating the energy in the energy storage spring 59. At this time, the movable display board 50 is in a positional relationship as shown in FIG. 15c, and the movable display board 50
The approximate elapsed time after power is retransmitted to the power line L can be determined by the position of the notch 50a.

After the power is retransmitted, after a certain period of time (approximately 3 hours) required for patrols to investigate the cause of the accident, the movable display board 5 will be turned on again as shown in Figure 15a.
The accident display section 51b of the fixed display board 51 is completely covered by the normal state display surface 50b. At the same time, the operating piece 52a of the driven gear 52 switches to the switch lever 6.
4, the movable contact 45 is switched from the fixed contact 47 to the 46 side, and the synchronous motor
SM stops. Note that this normal display state and the energy storage state of the energy storage spring 59 are the same as those of the clutch gears 56, 5.
This is maintained by a means (not shown) that allows rotation only in the return direction.

If the abnormal current flows again after the return operation is completed or during the return operation, the drive coil 40 will operate in the same way and the accident display section 51b will appear again.
The operations described above are then repeated.

Now, in the embodiment of the present invention, a power line clamping mechanism consisting of upper and lower clamp fittings 23 and 22 is mounted via a mounting bolt 17 to the upper part of the main body case 1 which is integrally molded with an insulating material made of rubber or the like. , Similarly, on the top of main case 1,
The lower core pieces 9, 14 forming the cut cores 7, 12 for detection and return are buried, and tapered grooves are formed along the outer edges of the cut surfaces 9a, 14a of the lower core pieces 9, 14 so that the width becomes narrower toward the bottom. Annular grooves 1f are formed respectively, and the upper core pieces 8 and 13 corresponding to the lower core pieces 9 and 14 are inserted into the lid cases 2 and 3 integrally molded from rubber, respectively,
The annular groove 1 is provided on each lower end surface of the lid cases 2 and 3.
Tapered annular protrusions 2a and 3a are formed to fit tightly into the lids 2 and 3, respectively, and a connecting plate 5 is formed on the upper surface of both lids 2 and 3.
is fitted to connect both lid bodies 2 and 3, and the connecting plate 5
is pressed toward the main body case 1 side by a screw 18 screwed into the upper end female threaded portion 17b of the mounting bolt 17 to press and fix the upper core pieces 8, 13 and the lower core pieces 9, 14, and further the main body case 1 A unit in which a display drive section B, a return drive section I, a display mechanism section J, etc. are integrally assembled is removably housed in the skirt section 1a, and the display mechanism section J is also installed from the bottom of the skirt section 1a. Since the operation can be visually observed, the structure of the entire device can be simplified and manufacturing and assembly can be easily performed, and the close contact between the annular groove 1f and the annular protrusions 2a and 3a prevents rainwater from entering. Therefore, there is no need to select and attach a waterproof cap or the like as a separate member, thereby reducing manufacturing costs and improving durability.

Note that the present invention can also be embodied in the following embodiments.

(1) The detection and recovery cut cores 7 and 12 are combined into one cut core so that power for detection and recovery can be obtained from this.

(2) The display drive section B, return power supply section H, return drive section I, display drive section J, etc. may be changed to other arbitrary mechanisms (not shown).

As described in detail above, the present invention includes a clamp mechanism that clamps a power line, a cut core that is arranged annularly around the power line and detects the current flowing through the power line, in the upper part of the display device, and a power line in the lower part of the display device. A display drive section is provided that is operated by a detection signal from the cut core when a current of a certain level or higher passes through the cut core, and a display mechanism section that operates to display a display by the operation of the display drive section. In an abnormal current display device that is assembled so as to be located at the bottom so that it can be visually observed, the main body case is integrally molded with an insulating material except for the display part on the lower end surface.
The lower core piece that constitutes the detection cut core and the return cut core is inserted and supported in the upper part of the main body case, and a tapered annular groove is formed along the outer edge of each cut surface of the lower core piece, the width becoming narrower toward the bottom. The lower core piece and the corresponding upper core piece are each inserted into a lid case integrally molded with rubber, and each lower end surface of the lid case has a tapered annular protrusion that is tightly fitted into the annular groove. The entire device can be assembled by forming two parts, connecting both lid cases by a connecting plate fitted from above, and pressing the connecting plate toward the main body case to press and fix the upper core piece and the lower core piece. The structure of the cap is simplified and compact, making it easy to manufacture and assemble, and the close contact between the annular groove and the annular protrusion prevents rainwater from entering, making it possible to use a waterproof cap as a separate component. No need to select and install
This has the effect of lowering manufacturing costs and improving durability.

[Brief explanation of drawings]

FIG. 1 is a half-longitudinal cross-sectional view showing an embodiment of the abnormal current display device of the present invention, FIG. 2 is an enlarged half-longitudinal cross-sectional view of only the vicinity of the cut core, and FIG. 3 is a cross-sectional view taken along the line X-X of FIG. 2. , Fig. 4 is a plan view of the main body case, Fig. 5 is a perspective view of the lid case seen from below, Fig. 6 is a perspective view showing the cut core holding plate, and Fig. 7 is a perspective view showing the upper and lower clamp fittings. Figure 8 is a perspective view of the mounting frame and protective case, Figure 9 is an electric circuit diagram, Figure 10 is a graph showing the magnetization characteristics of the transformer, and Figure 11 is a graph showing the magnetization characteristics of the transformer.
The figure is a vertical sectional view showing a unit in which the display drive section, display mechanism section, etc. are assembled together, Figure 12 is a sectional view taken along the Y-Y line in Figure 11, and Figure 13 is only the movable display board and fixed display board. Fig. 14 is a perspective view of only the driven gear, Fig. 15 a to c are front views showing the display status of the display board, and Fig. 16 shows the relationship between the current and voltage generated in the transformer. This is a graph showing. Main body case 1, annular groove 1f, annular protrusions 2a, 3
a, connecting plate 5, detection cut core 7, upper core pieces 8, 13, lower core pieces 9, 14, cut surface 9a,
14a, cut core for return 12, mounting bolt 1
7. Head 17a, female thread 17b, screw 18, lower (upper) clamp fittings 22, 23, mounting frame 2
6. Protective case 35, abnormal current detection section A, display drive section B, recovery power supply section H, recovery drive section I, display mechanism section J.

Claims (1)

[Scope of Claims] 1. A clamp mechanism that clamps a power line and a cut core that is arranged in an annular shape around the power line and detects the current flowing through the power line are provided at the top of the display device, and at the bottom thereof, a clamp mechanism that clamps the power line at a certain level is provided. A display drive section that is operated by the detection signal of the cut core and a display mechanism section that operates to display a display by the operation of the display drive section are provided so that the display mechanism section can be visually viewed from below when the above current passes through. In the abnormal current display device assembled to be located at the bottom of the body, the main body case 1 is integrally molded with an insulating material except for the display part on the lower end surface, and a detection cut core 7 and a detection cut core 7 are mounted on the upper part of the main body case 1. The lower core pieces 9, 14 constituting the return cut core 12 are inserted and supported, and a tapered annular groove 1f is formed along the outer edge of each cut surface 9a, 14a of the lower core pieces 9, 14, the width becoming narrower toward the bottom. The upper core pieces 8 and 13 corresponding to the lower core pieces 9 and 14 are respectively inserted into the lid cases 2 and 3 integrally molded from rubber,
The annular groove 1 is provided on each lower end surface of the lid cases 2 and 3.
tapered annular protrusions 2a and 3a that are tightly fitted to the body case 1 are formed, respectively, and the both lid cases 2 and 3 are connected by a connecting plate 5 that is fitted from above, and the connecting plate 5 is connected to the main body case 1. An abnormal current display device for a power line, characterized in that upper core pieces 8, 13 and lower core pieces 9, 14 are fixed in pressure contact by pressing sideways. 2 Mounting bolts 17 with insert-fixed heads 17a are installed upright in two places on the upper part of the main body case 1 formed integrally with an insulating material, and a female threaded part 17b provided at the upper part of the mounting bolts 17 has a Connecting plate 5
Press the upper core pieces 8, 13 toward the main body case 1 side.
The power line abnormal current display device according to claim 1, wherein a screw 18 is screwed together to press and fix the lower core pieces 9 and 14. 3 The mounting bolt 17 has the locking pieces 2 of the upper and lower clamp fittings 23 and 22 that constitute the clamp mechanism.
3e and 22e are loosely fitted, and both clamp fittings 2
3. The power line abnormal current display device according to claim 1, wherein 3 and 22 are tightened and fixed by nuts 25 screwed onto the mounting bolts 17. 4 A patent claim in which a skirt portion 1a is integrally molded in the lower part of the main body case 1, and a mounting frame 26 into which a display drive portion B and a display mechanism portion J are inserted is removably housed within the skirt portion 1a. The power line abnormal current display device according to item 1.