JPH11295348A - Current sensor structure for clamp sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce measurement error regardless of the position of a conductor to be measured inserted into a clamp sensor. SOLUTION: A clamp sensor comprises a pair of current sensors 11 formed by applying a winding 22 to an insulating core material 17 wherein larger diameter parts 15, 16 are provided at the abutting ends 12, 13. When the current sensors 11 is formed by applying a winding to an insulating hollow tube, parts to be overlapped and collapsed upon closure are formed at the base and forward abutting ends.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a clamp sensor which can be freely opened and closed even when a gap is present between the butt ends of current coils which come into contact when the clamp sensor is closed.
The present invention relates to a current sensor structure for a clamp sensor capable of suppressing an adverse effect on measurement from the gap.

[0002]

2. Description of the Related Art A clamp-type ammeter having a clamp sensor that can be opened and closed can measure a current value by directly introducing a conductor to be measured in a hot-line state into the clamp sensor. Has been widely used in the field of

[0003]

However, in the clamp-type ammeter described above, it is inevitable from the structural point that a gap is formed between the butted ends of the current sensor when the clamp-type ammeter is closed. When measuring the conductor to be measured at a position near the gap after introducing the conductor to be measured, the measured current value may be displayed lower than the true value, and after the measurement conductor is introduced into the clamp sensor. There is a measurement complexity in that the conductor to be measured must be measured away from the butt end.

SUMMARY OF THE INVENTION In view of the above-mentioned problems in the prior art, the present invention provides a clamp sensor capable of performing measurement with a reduced measurement error regardless of the position of a conductor to be measured introduced into the clamp sensor. It is an object of the present invention to provide a current sensor structure for the same.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to achieve the above-mentioned object. Among them, the structural feature of the first invention is that a left-side sensor portion which is pivotally supported by an instrument body so as to be openable and closable. And a clamp sensor comprising a right sensor portion, and a substantially annular shape when the clamp sensor is closed, and a direct or indirect contact with each other is freely arranged via respective butted ends. In these current sensors, these current sensors are formed by applying a winding to an insulating core material, and making the outer diameter of the portion where the butted ends are located larger than the outer diameter of the other portions. Having a large diameter portion.

In this case, the large-diameter portion can be formed by increasing the number of windings of a core material having a uniform outer diameter, or by increasing the outer diameter of a corresponding portion of the core material. Further, as the core material, a hollow tube or a bobbin provided with a magnetic core can be used.

Another feature of the second invention is that the clamp sensor comprises a left sensor part and a right sensor part which are pivotally supported by the instrument body so as to be openable and closable. In a pair of current sensors, which are shaped and arranged so that direct or indirect contact with each other can be freely made via respective butted ends, the pair of current sensors formed by applying a winding to an insulative hollow tube In each of the current sensors described above, the abutting ends located at the base end and the distal end are formed by crushed portions which alternately overlap and come into contact with each other when closed.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention constitutes a clamp sensor comprising a left sensor part and a right sensor part which are pivotally supported by an instrument body so as to be openable and closable. The present invention is applied to a pair of current sensors that are freely arranged to directly or indirectly contact with each other via the butted ends of the current sensors.

FIG. 1 is an explanatory view showing the manufacturing steps of one example of the first invention of the present invention as (a) to (c), wherein a winding 22 is applied to an insulating core 17. The formed current sensor 11 has a large diameter portion 15, 1 in which the outer diameter of the portion where the respective butted ends 12, 13 are located is made larger than the outer diameters of the other portions through the following steps.
6 can be provided.

That is, as shown in FIG. 1A, a hollow tube 18 having a uniform outer diameter and made of, for example, flexible and soft vinyl chloride is used as a core material 17 and a base end portion 18a thereof.
After the heat-shrinkable tube 21 is attached to the end portion 18b and the thick portions 19 and 20 are formed, the winding 2 is wound around the entire surface of the hollow tube 18 including the thick portions 19 and 20.
2 to provide the base end 1 as shown in FIG.
The flexible coil body 14 having the large-diameter portions 15 and 16 at the start end portion 18b and the straight coil portion 8a can be formed.
In this case, the thick portions 19 and 20 may be formed by winding an insulating tape or applying an insulating paint, for example, in addition to the heat-shrinkable tube 21.

The flexible coil body 1 thus formed
The butt end 4 is very easily curved so as to have a substantially semicircular shape as shown in FIG. The current sensor 11 having the large diameter portions 15 and 16 in the portions 12 and 13 can be formed. The current sensor 11 can be used as a Rogowski coil.

The current sensor 11 is housed separately in a left-hand holder and a right-hand holder (not shown) prepared in advance to form a left sensor and a right sensor, respectively.
A clamp sensor can be formed by pivotally supporting the left sensor section and the right sensor section on the instrument body so as to be freely opened and closed. As the core material 17, besides a hollow tube made of vinyl chloride, a hollow tube made of a hard insulating resin previously curved and formed into a predetermined shape can be used, and a bobbin material having a magnetic core can be used. Can also. When a hollow tube or bobbin material made of an insulating resin is used as a core material, the thick portion 1
9 and 20 can be integrally formed of the same resin material, or can be formed by attaching a heat-shrinkable tube, winding an insulating tape, or applying an insulating paint.

The large-diameter portions 15 and 16 in the present invention are formed by increasing only the number of windings of the base end portion and the distal end portion with respect to a core material having a uniform outer diameter, other than the illustrated example. In addition, the core material itself may have the same thickness, and may be formed by increasing only the outer diameter of the base end portion and the distal end portion.

On the other hand, of the present invention, the second invention is applied to a pair of current sensors formed by winding a soft hollow tube such as a vinyl chloride tube, and is particularly embodied. It can be suitably used as a Rogowski coil.

FIG. 2 shows an example of the second aspect of the present invention. A current sensor 31 has a winding 32 around a hollow tube 18 made of, for example, a vinyl chloride tube shown in FIG.
And crushing portions 34, 36 at the butting ends 33, 35 located at the base end 31a and the tip 31b, respectively.
Is formed.

In this case, the crushing portions 34 and 36 of the current sensor 31 are provided with a pair of current sensors 31 and
It is formed by crushing so that when they are closed, they can be staggered and overlap each other.

That is, one of the crushed portions 34 and 36 provided in the current sensor 31 is, for example, the base end 31a.
The crushing part 34 located on the side, the crushing part 36 located on the other side, for example, the tip part 31b side,
Conversely to the crushing portion 34, each is formed by crushing the front side toward the back side to a thickness that is approximately half the thickness.

The pair of current sensors 31, 31 formed in this manner are arranged so that one side and the other side are upside down, and are opposed to each other as shown in FIG. As a result, the crushed portion 34 of one current sensor 31 and the crushed portion 35 of the other current sensor 31
As shown in FIG. 2B, the first crushing portion 35 alternately overlaps with the crushing portion 34 of the other current sensor 31 in the front-rear direction and can be brought into contact with each other.

FIG. 3 is a front view showing another example of the second invention, in which the crushing portions 34 and 36 of the current sensor 31 have a thickness such that both the lower surface side and the upper surface side are substantially half the thickness. It is formed by crushing up to

The pair of current sensors 31, 31 formed in this manner are arranged so that one side and the other side are upside down and opposed to each other as shown in FIG. The crushed portion 34 of one current sensor 31 overlaps the crushed portion 35 of the other current sensor 31 and the crushed portion 35 of one current sensor 31 alternately overlaps with the crushed portion 34 of the other current sensor 31 in the vertical direction. Can be brought into contact with each other.

According to the first aspect of the present invention, the winding 22 is applied to the core 17 made of a bobbin having a hollow tube 18 and a magnetic core (not shown). Each butt end 12,1
It is possible to form the current sensor 11 having the large-diameter portions 15 and 16 in which the outer diameter of the portion where 3 is located is larger than the outer diameter of the other portions.

In addition, it is generally said that the larger the winding diameter of the wound wire after the current sensor is applied, the larger the output value of the current sensor can be. By arranging the prepared current sensors 11 and 11 so as to face each other in a positional relationship symmetrical with respect to the left and right lines, the portions where the butting ends 12 and 12 and the butting ends 14 and 14 facing each other when closing are located. Therefore, the output value can be increased as compared with other parts.

Therefore, for example, even when the conductor to be measured is positioned in the clamp sensor located near the abutting ends 13, 13 in which a gap is interposed, the measured current value is smaller than the true value. Since it is possible to effectively suppress the adverse effect on the measurement from the gap such as being displayed low, it is possible to perform the measurement work smoothly without worrying about the position of the conductor to be measured in the clamp sensor. Can be. In addition, since the current sensors 11 arranged in a pair and opposed to each other can share the same shape, the product cost can be reduced accordingly.

When the current sensor 11 has the large diameter portions 15 and 16 provided by increasing the number of turns of the windings 22 with respect to the core material 17 having a uniform outer diameter, if only the number of members is used, In addition, by reducing the number of assembling steps, the cost can be effectively reduced.

Further, the current sensor 11 has large diameter portions 15 and 16 in which the outer diameter of the corresponding portion of the core 17 is increased in advance, and the windings 22 having the same number of turns are uniformly applied thereto. In some cases, the work of winding the windings 22 can be simplified and contribute to improvement of workability.

On the other hand, according to the second aspect of the present invention, after the winding 32 is applied to the hollow tube 18 as shown in FIG. 1, the butted end portions 3 located at the base end portion 31a and the distal end portion 31b are formed.
Each of the crushed portions 34, 36 crushed to one side so as to be able to alternately overlap with each other.
Can be formed.

In addition, it is generally considered that the output value of the current sensor can be increased as the number of windings of the winding increases, which also indicates that the current sensor has a structure as shown in FIG. 2 or FIG. When the current sensors 31, 31 prepared as a pair with each other are opposed to each other in a positional relationship symmetrical with respect to the left and right and closed, for example, as shown in FIG.
As shown in FIG. 2, the crushed portion 36 of the current sensor 31 located on the left side and the crushed portion 34 of the current sensor 31 located on the right side overlap with each other, so that the butt end 35 and the butt end 3 are positioned. Since the number of turns of the winding 32 is twice as large as that of the other portions, the output value can be increased as compared with the other portions.

Therefore, for example, the butted end portions 3 which overlap each other with a gap as shown in FIG.
Even if the conductor to be measured is positioned in the clamp sensor located near 3, 35, there is an adverse effect on the measurement from the gap such that the measured current value is displayed lower than the true value. Can be effectively suppressed, so that the measuring operation can be performed smoothly without worrying about the position of the conductor to be measured in the clamp sensor. Moreover, the pair of current sensors 31, 31
As shown in FIGS. 2 and 3, the same shape can be used in common, so that the product cost can be reduced accordingly.

[0029]

As described above, according to the first aspect of the present invention, by winding a core material made of a hollow tube, a bobbin having a magnetic core, or the like, each butt end portion is provided. Since the current sensor having a large-diameter portion whose outer diameter is larger than the outer diameters of the other portions can be formed, the portion where the butted end portions facing each other when the sensor is closed is located at another position. The output value can be increased as compared with the region.

Therefore, the measuring operation can be performed smoothly without worrying about the position of the conductor to be measured in the clamp sensor. In addition, since the current sensors which are arranged in a pair and face each other can share the same shape, the product cost can be reduced accordingly.

When the large-diameter portion is provided with a larger number of windings relative to a core material having a uniform outer diameter, the cost can be reduced by reducing not only the number of members but also the number of assembling steps. Can be effectively contributed. Furthermore, if the outer diameter of the corresponding part of the core material is increased in advance and the same number of windings are applied uniformly to it, and the large-diameter part is formed, the winding work of the winding is simplified. And contribute to improvement of workability.

On the other hand, according to the second aspect of the present invention, the current sensor can be formed by providing the crushed portions at the butted ends so as to be staggered so as to be able to overlap each other. When the crushed portions are closed so that they are opposed to each other so as to be symmetrical with respect to the right and left lines, the output value can be made larger at the portion where the butted end portion is located as compared with other portions.

Therefore, even if the conductor to be measured is positioned in the clamp sensor located near the abutting end, the measurement may be performed because the measured current value is displayed lower than the true value. Since the adverse effects on the measurement can be effectively suppressed, without worrying about the position of the conductor to be measured in the clamp sensor,
Measurement work can be performed smoothly. In addition, since the pair of current sensors can share the same shape, the product cost can be reduced accordingly.

When a hollow tube is used as the core material, the characteristics of the Rogowski coil, which is one mode of the coreless coil, can be used in principle, so that a wide measurable range can be secured. Can be.

[Brief description of the drawings]

FIG. 1 shows the manufacturing process of one example of the first invention (a).
FIG.

FIG. 2 is a plan view of an operation state at the time of opening and closing, with (a) as a front view at the time of closing according to an example of the second invention.
Respectively.

FIG. 3 is a front view showing an operation state at the time of opening and closing according to another example of the second invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Current sensor 12, 13 Butt end part 14 Flexible coil body 15, 16 Large diameter part 17 Core material 18 Hollow tube 18a Base end part 18b Tip part 19, 20 Thick part 21 Heat shrinkable tube 22 Winding 31 Current sensor 31a Base end 31b Tip 32 Winding 33,35 Butt end 34,36 Crushed part

Claims (8)

[Claims] 1. A clamp sensor comprising a left sensor part and a right sensor part which are pivotally supported by an instrument body so as to be openable and closable. A pair of current sensors, which are arranged so that they can freely contact each other directly or indirectly. These current sensors are formed by applying a winding to an insulating core material, A current sensor structure for a clamp sensor, comprising a large-diameter portion in which the outer diameter of a portion where is located is larger than the outer diameters of other portions. 2. The current sensor structure for a clamp sensor according to claim 1, wherein said large-diameter portion is formed by increasing the number of windings of a core material having a uniform outer diameter. 3. The current sensor structure for a clamp sensor according to claim 1, wherein said large diameter portion is formed by increasing an outer diameter of a corresponding portion of a core material. 4. The current sensor structure for a clamp sensor according to claim 1, wherein said core member is a hollow tube. 5. The current sensor structure for a clamp sensor according to claim 1, wherein said current sensor is a Rogowski coil. 6. The current sensor structure for a clamp sensor according to claim 1, wherein said core material has a magnetic core. 7. A clamp sensor comprising a left sensor part and a right sensor part which are pivotally supported by the instrument body so as to be openable and closable, and when the clamp sensor is closed, have a substantially annular shape via respective butted ends. A direct or indirect contact between the pair of current sensors is freely arranged, wherein each of the pair of current sensors formed by applying a winding to an insulating hollow tube, a base end portion and A current sensor structure for a clamp sensor, wherein a butt end portion located at a tip end portion is formed by a crushing portion which alternately overlaps and comes into contact when the butt portion is closed. 8. The current sensor structure for a clamp sensor according to claim 7, wherein the current sensor is a Rogowski coil.