JPH11258285A - Electric resistance measurement device and electric resistance measurement method for conductive work boots - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reproducibility and measurement accuracy of an electric resistance measured value. SOLUTION: This device is provided with a felt electrode 7 to be brought into contact with the inner surface 34 of a shoe sole 33, a copper plate 3 to be brought into contact with the outer surface 35 of the shoe sole 33, a housing box main body 24 for laying the copper plate 3 at the bottom, a housing box upper lid 17 to be put on the housing box body 24, a top plate 18 for supporting the lower surface of the housing box upper lid 17 by a flat surface and a supporting bar 19 and a foot mold 20 for supporting the top plate 18. The felt electrode 7 is tightly adhered to the inner surface 34 of the shoe sole by the weight of a plastic tank 21 placed on the housing box upper lid 17, conductors are respectively connected to the felt electrode 7 and the copper plate 3, a power source is connected between the conductors through an ammeter and a voltmeter and the electric resistance of the shoe sole 33 is measured from the measured values of the current and the voltage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for measuring the electrical resistance of a conductive work shoe for measuring the electrical resistance of a conductive work shoe and a method for measuring the electrical resistance of the conductive work shoe using the same. is there.

[0002]

2. Description of the Related Art When climbing on a support of a high-voltage line, for example, a 500 kV overhead power transmission line, or approaching a charged part in a substation or the like, an insulated object (or a human body) is caused by the +,-in the object. The charge is separated and an electrostatic induction phenomenon appears on the surface. Although this phenomenon is merely a charge separation in the object, the electric potential of the object rises and becomes equivalent to an apparently charged object. Therefore, a mechanical phenomenon and a discharge phenomenon occur near the object.

The adverse effect of this phenomenon on the human body is an electric shock caused by a discharge phenomenon. In many cases, the electric shock is not strong enough to cause an electric shock, but there is a risk that a shock or a contact with a machine or the like may be caused by a shock or stiffness due to the electric shock. In addition, the discomfort and fear caused thereby may threaten worker safety.

[0004] Leakage of dielectric charge by grounding is effective in preventing electric shock due to the above-mentioned discharge phenomenon. That is, in the case of a metal conductor, it is directly grounded, but a conductor other than a metal having a conductivity of 1 × 10 to ¹⁰ s / m or more (volume resistivity of 1 × 10 ¹⁰ Ω · m or less) or a conductor in an intermediate region is indirectly grounded. I do. In particular, conductive work shoes and conductive work clothes are used to ground the human body so that the human body is not always insulated from the ground. Among them, the conductive work shoes reduce the induced voltage of the human body, and the conductive work clothes reduce the human body current by dividing the induced current flowing through the human body into the conductive work clothes.

Here, the upper limit of the control of the electric resistance of the conductive work shoes will be described. In order to prevent electric shock, the charged amount of the human body needs to be 2 to 3 × 10 to ⁷ coulombs or less (Technical Guidelines for Industrial Safety Research Institute, Static Safety Guidelines (1978, 1
988)). Normally, the capacitance C of the human body is 90 × 10 to ¹² farads, and the charged potential V of the human body when the charge amount Q is 3 × 10 to ⁷ coulombs is as follows: V = Q / C = (3 × 10 to ⁷ ) / the ^{(90 × 10 ~ 12) =} 3333.3 = 3000 [V].

On the other hand, if the limit I of the current flowing through the human body is set to 1.8 mA from the data on the allowable current in the human body (CF. Dalgiel, 1961), the electric resistance R at the limit of the occurrence of electric shock is R = E / I = 3000 / (1.8 × 10 ³ ) = 1.7
× 10 ⁶ [Ω]. Therefore, a disaster or obstacle can be prevented if it is at least 1 × 10 ⁶ [Ω]. However, this value is merely a theoretical value and a limit value, and the lower the leakage resistance, the more effective the antistatic effect. Also, taking into account the increase in resistance due to dirt on the sole surface of the shoe, for example, 1 × 10 ⁴ [Ω] for unused shoes
The upper limit of the electric resistance is set.

By the way, as an electric resistance measuring device for measuring the electric resistance of a conductive work shoe for reducing the induced voltage of the human body due to grounding, a device for putting a human foot directly into the shoe and applying a load to measure the resistance. It has been known.

FIG. 5 shows an electric resistance measuring apparatus 40 for a conductive work shoe according to the prior art, in which a conductive work shoe 32 is mounted on an earth-side metal plate electrode 37 placed on an insulating table 41. , And the aluminum foot-type electrode 43 is brought into contact with the shoe sole 33 inside the conductive work shoes by applying a load of a weight 44 of 20 kgf via a support rod 45, and the current and voltage between the two electrodes are measured. It is measured by an ammeter 27 and a voltmeter 28.

[0009]

However, the above-described apparatus for directly placing a human foot in a shoe to apply a load has a risk of low-voltage electric shock and is inefficient. Also, since the human foot is directly inserted into the shoes, there is variation in the measurement due to differences in the size of the load based on individual differences, differences in how to apply, differences in conditions such as wetness of the foot, and improvement in measurement accuracy. Was difficult.

Further, in the measuring device shown in FIG. 5, the fear of low-voltage electric shock has been eliminated, but the contact state between the aluminum foot-shaped electrode 43 and the upper surface of the shoe sole 33 tends to be non-uniform. Variations occurred in the measurement, and the reproducibility of the measurement value and the measurement accuracy were lacking in some cases. In addition, there was an unstable point in how the load was applied, and there were difficulties in the safety of the measurement work and the efficiency of the measurement.

An object of the present invention is to improve the reproducibility and measured accuracy of the measured electric resistance.

[0012]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a case having an open upper end capable of storing a conductive work shoe to be measured, an upper cover for covering the upper end opening of the case, A conductive first electrode that is installed on the inner bottom surface of the conductive work shoe and is placed in contact with the shoe sole side of the conductive work shoe, and an insulating last that is inserted into the conductive work shoe; A conductive and flexible second electrode disposed between the last and the inner surface of the sole of the conductive work shoe, and connected to the first and second electrodes, respectively. A conductive wire, a support rod connected to the upper part of the last, and a flat plate connected to the upper end of the support rod and held substantially horizontally, the upper surface of the flat plate is formed so as to protrude from the upper end of the case. The upper lid has a hanging edge portion loosely fitted to the outer peripheral surface of the case. In electric resistance measuring device of the conductive work shoes made have.

[0013] Since the upper lid has a hanging edge that loosely fits the outer peripheral surface of the case, the upper lid is loosely fitted over the outer peripheral surface of the case and covers the outer peripheral surface when it moves slightly in the vertical direction. You will be guided along. The conductive work shoes to be measured are housed in the case from the upper end opening of the case, and placed on the first electrode provided on the inner bottom surface such that the shoe bottom side is in contact with the first electrode. An insulating last is inserted into the inside of the conductive work shoe placed on the first electrode.
At this time, a second electrode having conductivity and flexibility is arranged between the last and the inner surface of the shoe sole.

Further, a support bar is connected to an upper portion of the last, a flat plate held horizontally is connected to an upper end of the support bar, and an upper surface of the flat plate is formed to protrude from an upper end of the case. As a result, the upper lid can be stably placed on the flat plate, and a slight vertical movement can be guided along the outer peripheral surface of the case. By placing a weight on the upper lid, a load due to the weight is applied to the second electrode from the upper lid via the flat plate, the support rod, and the last. By applying a load with the size of the weight being set appropriately, the second electrode has flexibility and thus closely adheres to the inner surface of the shoe sole.
Therefore, the electrical resistance of the shoe sole between the first electrode and the second electrode is accurately captured and measured, so that the reproducibility of the measured value and the measurement accuracy are good. In addition, since the reproducibility is good, it is not necessary to repeat the measurement many times, the work efficiency is improved, and a reliable electric resistance measurement can be performed. In addition, the measuring operation can be performed safely.

In the above-mentioned electric resistance measuring apparatus for conductive work shoes, the second electrode is formed by tangling a conductive wire. The electric resistance measuring apparatus for conductive work shoes provided with the second electrode includes a second electrode having pressure resistance and durability in addition to the action of the electric resistance measuring apparatus for conductive work shoes. Become.

Further, according to the present invention, there is provided any one of the above-described electric resistance measuring apparatus for conductive work shoes, wherein a weight of a polytank filled with water is placed on the upper surface of the upper lid, and the first and second electrodes are provided. The present invention is a method for measuring the electric resistance of a conductive work shoe, wherein a power supply is connected to a lead wire connected to the power supply via an ammeter and a voltmeter, and the electric resistance of the sole is measured from the measured values of the current and the voltage. According to this electric resistance measuring method, the electric resistance of the shoe sole is accurately captured and measured, so that the reproducibility of the measured value and the measuring accuracy are good. In addition, since the reproducibility is good, it is not necessary to repeat the measurement many times, the work efficiency is improved, and a reliable electric resistance measurement can be performed. Moreover,
Measurement work is safe.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of a device for measuring electric resistance of a conductive work shoe according to the present invention and a method of using the same. In addition, in FIGS.
The same or equivalent parts are denoted by the same reference numerals.

FIG. 1 is a partial cross-sectional side view showing an embodiment of an electric resistance measuring apparatus for conductive work shoes according to the present invention together with a measuring circuit. FIG. 2 is a front view of FIG. The electric resistance measuring device 1 of the present embodiment measures the electric resistance between the inner and outer surfaces of the sole of the conductive work shoe 32. The conductive work shoes 32 are used when working near a high voltage object with a high voltage applied thereto, and the soles are conductive and prevent the problem of electrostatic induction induced near the high voltage.

The electric resistance measuring device 1 includes a storage box main body 24 having an open upper end capable of storing the conductive work shoes 32 to be measured, and a storage as an upper lid which covers the upper end opening of the storage box main body 24. Box top lid 17 and conductive work shoes 32
The second part is brought into contact with the inner surface 34 of the shoe sole 33 which is the part to be measured.
And the outer surface 35 of the sole 33
A copper plate 3 as a first electrode to be brought into contact with the metal plate; a pressing jig 16 for pressing the felt electrode 7 with a constant pressing force;
And an external electrode lead wire 4 and an internal electrode lead wire 9 which are connected to the felt electrode 7 respectively.

The felt electrode 7 has conductivity and flexibility, and is made of a conductive wire material, for example, a copper wire entangled in a felt shape. Alternatively, the felt electrode 7 may be woven in a mesh shape by entanglement of a copper wire. The felt electrode 7 has a thickness of about several millimeters, and is for bringing the pressing surface 20a of the pressing jig into close contact with the inner surface 34 of the shoe sole as uniformly as possible. Further, the felt electrode 7 can be fixed to the footprint 20.

The pressing jig 16 is for pressing the felt electrode 7 with a constant pressing force, for example, about 20 kgf. The pressing jig 16 is formed of an insulating material such as wood, plastic or the like which directly presses the felt electrode 7. A mold 20, a support bar 19 fixed substantially vertically to the last 20 and a support bar 1;
9 has a top plate (flat plate) 18 fixed to the upper end thereof and having a flat upper surface. The top surface of the top plate 18 is formed so as to protrude from the upper end of the storage box main body 24, and the size of the top plate 18 is at least as large as the width of the storage box main body. In the pressing jig 16, the support bar 19 is provided to be fixed substantially vertically to the last 20, but the support bar 19 and the last 20 may be detachably formed. By forming the support bar 19 and the last 20 detachably, the support bar 19 can be attached to the last 20 after the last 20 is put in the conductive work shoes 32. Easily conductive work shoes 3
2, the pressing jig 16 can be easily assembled.

On the top plate 18 of the pressing jig, a storage box upper cover 17 as an upper cover is put, and a plastic tank 21 is placed on the storage box upper cover 17. Since the size of the top plate 18 is large, the storage box upper cover 17 can be stably mounted on the top plate 18. Plastic tank 21
Can be easily adjusted and set by using a so-called polytank, using one 20 liter per work shoe, filling with an appropriate amount of water and filling with water. The device 1 of the present embodiment includes a pair of the same devices for measuring one foot (two work shoes).

FIGS. 3A and 3B show the storage box main body 24. FIG. 3A is a plan view and FIG. 3B is a front view. 4A and 4B show the storage box upper cover 17 of the storage box main body, wherein FIG. 4A is a plan view and FIG. 4B is a front view. The storage box main body 24 and the storage box upper lid 17 are formed of a plastic such as impact-resistant PVC, but if formed of transparent plastic, the installation state of the inner conductive work shoes 32 and the state during measurement can be observed. So convenient.
The conductive work shoes 32 (not shown) are placed on a copper plate 3 (not shown) provided on the inside of the bottom plate 25 of the storage box main body 24. The storage box upper lid 17 has a hanging edge 17a that fits loosely on the outer peripheral surface of the storage box main body 24.
8, when it is put on the storage box main body 24, the lid can be loosely fitted over the upper outside of the storage box main body 24 to cover it.
The upper outer side 24a of the four side walls is the edge 17 of the storage box upper lid.
Guide a.

Further, on one wall surface of the storage box main body 24,
Three terminal blocks 13, 13, 14 are provided, and terminal block 1 is provided.
3 and 13 are connected to the other end of the internal electrode lead wire 9 having one end fixed to the felt electrode 7.
Is connected to the other end of the external electrode lead wire 4 whose one end is fixed (FIGS. 1 and 2). Reference numeral 26 denotes a handle.

As a measuring circuit, as shown in FIG. 1, an ammeter 27, a voltmeter 28, and a single-phase slider bar 29 are provided, and 100 volts AC is applied between the terminals 30, 30. Incidentally, the measurement between the terminal block 14 and the two terminal blocks 13, 13 may be performed using a switch (not shown), or an ammeter 27 and a voltmeter 28 may be provided for each terminal block 13. good.

In order to measure the electric resistance of the conductive work shoes using the electric resistance measuring apparatus 1 having the above structure, a load of, for example, 20 kgf is applied by the pressing jig 16 and a current of 1 mA AC is applied between the upper and lower electrodes. And the resistance value R is determined by the following equation.

Resistance value R [Ω] = (voltage [V] when flowing 1 [mA]) / (0.001 [A]) Electric resistance measuring apparatus 1 of the present embodiment having the above structure
Works as follows. In other words, the copper mesh felt electrode 7 formed by entanglement of the copper wire ensures that the shape of the pressing surface 20a of the last is closely adhered to the shoe sole,
Pressure resistance and durability are ensured, and it becomes an optimal electrode. The constant pressing force of the pressing jig 16 is transmitted to the outer surface 35 of the shoe sole through the felt electrode 7 with a pressure as uniform as possible. Therefore, the electric resistance of the shoe sole between the felt electrode 7 and the copper plate 3 is accurately captured and measured, so that the reproducibility of the measured value and the measurement accuracy are good. In addition, since the reproducibility is good, it is not necessary to repeat the measurement many times, the work efficiency is improved, and a reliable electric resistance measurement can be performed. In addition, the measuring operation can be performed safely.

[0028]

According to the electric resistance measuring apparatus for conductive work shoes of the present invention, the reproducibility of the electric resistance measurement value and the measurement accuracy are improved, so that a reliable electric resistance measurement can be performed. Further, the work of measuring the electric resistance can be performed safely, and the efficiency of the measurement work can be improved.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional side view showing an embodiment of an electric resistance measuring device for conductive work shoes according to the present invention together with a measuring circuit.

FIG. 2 is a front view of FIG.

3A and 3B show a storage box main body, wherein FIG. 3A is a plan view and FIG. 3B is a front view.

4A and 4B show a storage box upper cover, wherein FIG. 4A is a plan view and FIG. 4B is a front view.

FIG. 5 is an explanatory diagram showing an example of an electric resistance measuring device for a conductive work shoe according to a conventional technique together with a measuring circuit.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 Electric resistance measuring device 3 Copper plate (first electrode) 4 External electrode lead wire (conductive wire) 7 Felt electrode (second electrode) 9 Internal electrode lead wire (conductive wire) 17 Storage box top cover (top cover) 18 Top plate (flat plate) 19) Support rod 20 Foot type 24 Storage box body (case) 32 Conductive work shoes 33 Sole 34 Inner surface 35 Outer surface

Claims (3)

[Claims] 1. A case in which an upper end capable of storing a conductive work shoe to be measured is opened, an upper lid covering the upper end opening of the case, and a shoe of the conductive work shoe installed on an inner bottom surface of the case. A conductive first electrode placed on the bottom side in contact with the conductive work shoe, an insulating last inserted into the conductive work shoe, and an inner surface of the sole and the sole of the conductive work shoe; A conductive and flexible second member disposed between
Electrode, a conductive wire connected to the first and second electrodes, a support rod connected to the upper part of the last, and a flat plate connected to the upper end of the support rod and held substantially horizontally. An electrical resistance measuring apparatus for conductive work shoes, comprising: a top surface of the flat plate protruding from an upper end of the case; and the upper lid having a hanging edge loosely fitted to an outer peripheral surface of the case. 2. The method according to claim 1, wherein the second electrode comprises:
An electrical resistance measuring device for conductive work shoes formed by entanglement of a conductive wire. 3. The electric resistance measuring apparatus for conductive work shoes according to claim 1, wherein a weight of a poly tank filled with water is placed on the upper surface of the upper lid, and the first and second electrodes are placed. A method for measuring the electrical resistance of a conductive work shoe, comprising connecting a power supply to a conductor connected to the power supply via an ammeter and a voltmeter, and measuring the electrical resistance of the sole from the measured values of the current and the voltage.