JPH0239750B2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field This invention provides a system for quickly detecting fault points such as ground faults and short circuits in back electrical lines by directly suspending them from electrical lines so that overcurrent caused by accidents passes through the electrical lines. This invention relates to an overcurrent passage display device that displays when an overcurrent has passed.

Prior Art The present applicant has already developed an overcurrent passage display device as shown in FIG.
6 and a transparent fluid 27 with a large specific gravity are stored in upper and lower layers, respectively, and a display valve 28 that can move up and down is arranged in the fluids 26 and 27. The display valve 28 normally operates on the display tube 2.
The display valve 28 is placed in the transparent fluid 27 so as to have a gap with respect to the display window 25a provided at the bottom of the display valve 27, and when an overcurrent flows, the display valve 28 is activated via a display drive section or the like that is detected by a current detector. The colored fluid 26 was pulled up and made visible through the display window 25a to indicate the passage of an overcurrent, and then, while resisting the resistance of the fluids 26 and 27, it was lowered with a delay due to its own weight and returned to the transparent fluid 27.

However, since the specific gravity of the indicator valve is made larger than the specific gravity of the transparent fluid so that it is normally located in the transparent fluid, the specific gravity of the indicator valve is relatively larger than the specific gravity of the colored fluid. Therefore, when an overcurrent passes, the indicator valve that is pulled up to the top of the colored fluid will quickly descend through the colored fluid and return to its original state when it falls under its own weight, resulting in a problem in which the time it takes to display the passing of an overcurrent will be shortened. .

Purpose The present invention aims to eliminate the above-mentioned drawbacks and provide an overcurrent passage display device that can extend the overcurrent passage display time.

Embodiment An embodiment embodying the present invention will be described below with reference to FIGS. 1 to 4.

This overcurrent passage display device can be roughly divided into a current detection section A that detects overcurrent, a display drive section B that is operated by the detection section, and a drive transmission mechanism section H that transmits the driving force of the display drive section B. and a display device I operated by the drive transmission mechanism H.

First, the current detection section A will be explained. This detection section consists of a detection current transformer CT attached to the electric wire L and a step-up transformer 1 connected to the transformer CT.
(may be omitted). 2
is a surge absorber connected in parallel to the secondary side of the step-up transformer 1.

Display driver B includes a full-wave rectifier D connected to the transformer 1, a capacitor C connected to the output side of the rectifier, and a bidirectional trigger diode TD and relay X connected in parallel to the capacitor. , a variable resistor R that is also connected in parallel to the capacitor C for changing the voltage applied to the capacitor C, a contact Xa of the relay X and a rotary solenoid RS that are also connected in parallel with the capacitor C. It consists of a series circuit of

The rotary solenoid RS has a structure in which the output shaft is rotationally driven when the rotary solenoid RS is energized, and when the excitation is released, the output shaft is rotated back to its original position by a return spring S that is an internal energy storage member. When the terminal voltage of the capacitor C reaches a certain value (for example, when an overcurrent flows), the trigger diode TD becomes conductive and the relay X is activated. As a result, the a contact Xa of the relay X is closed and the rotary solenoid RS is rotated by a predetermined angle in the driving direction.

Next, the drive transmission mechanism section H will be explained.

This drive transmission mechanism H is shaped like a string whose upper end is engaged with the drive transmission mechanism H for the first time when the output shaft of the rotary solenoid RS rotates once when an overcurrent passes and then rotates back to its original position by a return spring S. The member 5 is pulled up to a predetermined position, and after being pulled up, the string-like member 5 is freely lowered to its original position.

Next, the display device I will be explained.

Reference numeral 7 denotes a bottomed cylindrical display tube made of colorless and transparent synthetic resin or glass, which is provided below the main body case 6, and has a hook portion whose diameter is enlarged via a locking step portion 8 on the outer periphery of the lower end. 9 protrudes downward. Further, the outer periphery of the hook portion 9 is screwed into the opening 6a at the lower end of the main body case 6 so that the lower portion of the hook portion 9 projects from the lower edge of the main body case 6. The locking step 8 is pressed against the O-ring 12 in the annular groove 11 formed in the lower surface of the locking protrusion 10 protruding from the inner periphery of the opening 6a of the main body case 6, thereby ensuring watertightness. ing.

Reference numeral 13 is a synthetic resin lid that is watertightly glued to the upper end opening of the display tube 7, and a mounting tube is inserted through and fixed in the center, and a tubular magnet is arranged inside the mounting tube 14. At the same time, the magnetic fluid 15 is arranged so as to close the inside of the mounting tube 14.

Reference numerals 16 and 17 indicate a colored fluid (in this example, red) with low specific gravity and high viscosity, and a transparent fluid (in this example) with high specific gravity and low viscosity, which are stored in the display barrel 7 in required amounts in upper and lower layers, respectively. colorless)
It is. In addition, the ratio of the specific gravity of both 16 and 17 is 2.0
A setting above 1.5 is desirable because the two-layer separation is stable, but even if the setting is 1.5 or above, the longer the standing time is, the better the separation will be, so this setting is also acceptable. Both fluids 16 and 17 are liquids whose viscosity changes little due to changes in external environmental conditions, for example, silicone oil is used as the colored fluid 16, and Fluorinert (Minnesota Mining & MFG) is used as the transparent fluid 17.
Company (proprietary trademark), fluorocarbon oil, and other fluorine-based inert liquids are used to prevent them from mixing with each other.

In the colored fluid 16, there is used a pigment (red in this embodiment) whose specific gravity is equal to or greater than that of the fluid and smaller than the specific gravity of the transparent fluid 17. It is preferable that this pigment is uniformly soluble in the fluid, but even if it is precipitated in a layer below the colored fluid 16 when left still, it will impair the function of the colored fluid 16 in this embodiment. It's not a thing. 18 is always the fluid 16, 17
The lower end of the string-like member 5, which is inserted through the center of the valve body as an indicator valve and is located inside the valve body, is anchored to a bead 19 that is in contact with the lower surface.

This valve body 18 has flexibility and the colored fluid 16
It is made of a disk-shaped synthetic resin whose specific gravity is higher than that of the pigment and lower than that of the transparent fluid 17, and is fitted with a small gap to the inner periphery of the display tube 7 so as to be able to move up and down. A pair of semicircular spiral valves 21 are integrally formed in a symmetrical manner with a groove 20 recessed in the direction as a boundary. The butterfly valve shape 21 is made unable to rotate upward about the groove 20, and is only allowed to rotate downward.

In the normal state, the valve body 18 floats on the transparent fluid 17 and exists so that its entire lower surface is in contact with the transparent fluid 17, and the bottom 7 of the display tube 7 which also serves as a display window.
It is located with a gap from a.

The valve body 18 is integrally formed with a synthetic resin having a specific gravity smaller than that of the colored fluid 16, and a weight having a specific gravity greater than at least the colored fluid 16 and the pigment is attached to the center of the valve body 18 to form a weight portion. By doing so, the transparent fluid 17 as the entire specific gravity of the valve body 18
The lower surface of the valve body 18 may be brought into contact with the transparent fluid 17 by making the specific gravity smaller than that of the colored fluid 16 and larger than that of the colored fluid 16 and the pigment. If you do this,
The valve body 18 can be stabilized, and the time for the valve body 18 to settle in the colored fluid 16 can be easily set as required by appropriately changing the weight of the weight of the valve body 18 attached. Can be done.

To explain the operation of the overcurrent passage display device configured as above, when a normal load current is flowing through the electric wire L as shown in FIG. The display tube 7 is energized by
The valve body 18 is shown from the bottom 7a.

In this state, if an overcurrent flows through the electric wire L due to an accident, a transformed current is generated by the transformer CT, which is converted to direct current by the rectifier D via the transformer 1, and charges the capacitor C.

When the voltage of the capacitor C reaches a certain value,
Trigger diode TD becomes conductive and relay X
is excited and closes its a contact Xa. As a result, a return spring S equipped with a rotary solenoid RS
The output shaft is rotated by a predetermined angle in the driving direction against the elastic force of. After rotation, rotary solenoid RS
The output shaft starts returning rotation in the opposite direction to that described above, that is, in the counter-driving direction, by the built-in return spring S.

As a result, the valve body 18 of the display device I receives gravity and the fluid 1 through the string member 5 of the drive mechanism section H.
It is pulled upward while resisting the viscous resistance of 6 and 17.

At this time, the valve body 18 is rotated while the butterfly valve 21 is bent downward as shown in FIG.
It will be moved during 6th. The valve body 18 is positioned above the colored fluid 16 as shown in FIG. 3 to provide an overcurrent passage indication, and the color of the colored fluid 16 can be visually recognized through the bottom 7a of the display cylinder 7. After the valve body 18 is raised to a predetermined position by the string member 5,
As shown in FIG. 4, the valve body 18 begins to descend due to its own weight, is delayed by the resistance of the colored fluid 16, and returns to its original state after a predetermined time to display the normal state. When the valve body 18 is lowered, unlike the conventional case, the specific gravity of the valve body 18 is made smaller than the specific gravity of the transparent fluid 17, so that the valve body 18 descends slowly and with a delay.

As described in detail above, in the present invention, since the specific gravity of the indicator valve is made smaller than that of the transparent fluid and greater than that of the colored fluid, it is possible to lengthen the overcurrent passage display time.

[Brief explanation of drawings]

FIG. 1 is an overall schematic diagram of an embodiment embodying the present invention, FIG. 2 is a cross-sectional view of the display valve in the raised state, and FIG. 3 is a cross-sectional view of the overcurrent passage display state. FIG. 4 is a sectional view of the display valve in a lowered state, and FIG. 5 is a sectional view of a conventional display device. I... Display device, 16... Colored fluid, 17...
Transparent fluid, 18...Display valve (valve body).

Claims (1)

[Scope of Claims] 1. A current detection section disposed on an electric wire, a display drive section that mechanically operates when the detection section detects an overcurrent, and a display operation based on the detection operation of the display drive section. In the overcurrent passage display device, the display device includes a display tube in which a colored fluid with a low specific gravity and a high viscosity and a transparent fluid with a high specific gravity and a low viscosity are stored in upper and lower layers, respectively. When an overcurrent is detected, the indicator valve is pulled up into the colored fluid to indicate the passing of the overcurrent, and after the overcurrent is resolved, the indicator valve is delayed to fall against the resistance of the colored fluid due to its own weight. An overcurrent passage display device characterized in that the specific gravity is smaller than that of a transparent fluid and larger than that of a colored fluid so that it floats on the interface between the transparent fluid and the colored fluid. 2. The overcurrent passage display device according to claim 1, wherein the specific gravity of the transparent fluid is at least 1.5 times greater than the specific gravity of the colored fluid. 3. The indicator valve has a main body made of synthetic resin that has a specific gravity lower than that of the colored fluid, and a weight part that has a higher specific gravity than the colored fluid is provided on the main body, so that the overall specific gravity is lower than that of the transparent fluid, and The overcurrent passage display device according to claim 1 or 2, characterized in that the specific gravity is greater than the specific gravity of the colored fluid.