JP4077926B2 - Clamp sensor and clamp ammeter - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a clamp sensor and a clamp- type ammeter that are capable of greatly contributing to a reduction in product cost with a light weight and a small size by utilizing the characteristics of a Rogowski coil.
[0002]
[Prior art]
FIG. 7 shows a configuration example of a clamp sensor in a conventional general clamp-type ammeter. The magnetic core 3 is formed by laminating magnetic steel plates having a substantially arc shape, and the magnetic core 3 is covered with the magnetic core 3. A pair of core sensors 2 and 2 comprising a bobbin 4 and a winding 5 applied via the bobbin 4 are placed in core covers 6 and 6 which are attached to an ammeter body (not shown) so as to be freely opened and closed. The entire clamp sensor 1 is formed by storing each separately.
[0003]
[Problems to be solved by the invention]
However, according to the above-described conventional example, the magnetic core 3 itself is curved so as to have a substantially arc shape. Therefore, an expensive dedicated machine, which is a custom-made product, is used when winding a core wire using an automatic winding machine. It is necessary to use the winding 5 for use, and as a result, it is a major factor that increases the product cost.
[0004]
In addition, the clamp sensor 1 has the magnetic core 3 and thus requires a magnetic shield measure. In addition, the clamp sensor 1 causes a saturation phenomenon or increases the overall weight as the magnetic field strength increases. There were also inconveniences such as.
[0005]
Moreover, since the magnetic core 3 is formed by laminating a large number of magnetic steel plates, there is a design inconvenience that it is impossible to cope with a subsequent design change.
[0006]
On the other hand, as a detection coil for measuring a high current pulse, a winding is spirally formed on the outer periphery of a hollow core, and a current is measured by measuring a voltage between a winding start portion and a rewinding portion of the winding. A Rogowski coil is widely known.
[0007]
However, since the Rogowski coil needs to be wound at an equal pitch, a spiral guide groove is engraved in advance on the surface of the hollow core, and a core wire is wound along the guide groove. (For example, Japanese Utility Model Publication No. 56-57500, Japanese Utility Model Laid-Open No. 4-118667) and the like, it is required to be troublesome in that the core wire must be wound in alignment when performing winding. There was a problem that would increase the cost of the product.
[0008]
In addition, since this type of Rogowski coil is generally relatively large, there has been an inconvenience that a compact and handy structure with excellent operability has not yet been commercialized.
[0009]
In view of the above-mentioned problems found in the prior art, the present invention makes a significant contribution to reducing the product cost with a light weight and a small size by making the magnetic core unnecessary by utilizing the characteristics of the Rogowski coil in principle. An object of the present invention is to provide a clamp-type ammeter and a clamp sensor that can perform the above-mentioned.
[0010]
[Means for Solving the Problems]
The present invention has been made to achieve the above-mentioned object. Among them, the structural features of the clamp sensor according to the present invention include a one-side cover portion that is divided into two so that each has a substantially semicircular shape, and the like. An insulating cover that is attached to the instrument body so that it can be opened and closed so as to exhibit a substantially annular shape when the instrument body is closed with the side cover portion, and a winding is applied to the outer peripheral surface of the flexible tube made of an insulating material. In a clamp sensor comprising at least a flexible coil body that is housed separately in the one side cover part and the other side cover part, and each open end face that is in a positional relationship corresponding to the closed state is disposed facing each other . The flexible coil body is applied over the entire circumference so that a flexible tube made of an insulating material and a lead line consisting of a start line end part and a terminal line part are located on the base end side of the flexible tube. The wound windings, and At least to and a Kutsugae設been insulated cap winding site located on the proximal side and the distal side of the Shiwasei tube lies in the form.
[0011]
In this case, it is desirable that the flexible tube is provided with a large-diameter portion having an outer diameter larger than that of the other portion at the base end portion and the distal end portion. It is desirable to cover an insulating sleeve portion formed by attaching a heat-shrinkable tube separately to the windings positioned at least at the base end portion and the tip end portion excluding the lead wire.
[0012]
Further, the winding may be wound with the number of windings of the base end portion and the tip end portion being larger than the number of windings of other portions. Furthermore, the terminal line part in the lead-out line may be one that is inserted through the hollow part of the flexible tube from the tip side to the terminal side and pulled out. Furthermore, the winding is formed by winding multiple layers around a flexible tube to average the cross-sectional area of each winding layer when the winding layer is cut at one or more arbitrary positions. it can.
[0013]
It is preferable that the insulating caps are arranged so that the outer end surfaces thereof are in close contact with each other as the butted end surfaces. The one-side cover portion and the other-side cover portion are each divided in half so as to be freely divided so as to meet each other. The insulating cap and the one-side cover portion and the other portion of the portion where the insulating cap is inscribed are separated. It is desirable that each of the side cover portions be provided with irregularities that fit together so that the flexible coil body can be positioned and accommodated freely. Further, the one-side cover portion and the other-side cover portion, which are each divided in half and freely formed to meet each other, are fixed to each other by fixing the respective contact boundary portions after the face-to-face matching. It can also be integrated separately. Furthermore, it is preferable that the insulating cap is provided with a protrusion on the inner bottom surface thereof that can be press-fitted into the hollow portion of the flexible tube.
[0014]
On the other hand, a structural feature of the clamp-type ammeter according to the present invention is that the clamp sensor according to any one of claims 1 to 10 is provided.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a front view showing a part of an example of a clamp-type ammeter according to the present invention with a part thereof broken, and has butted end faces 39, 39 that come into contact with and separate from each other when opening and closing. The clamp type ammeter 11 is formed by attaching the clamp sensor 21 formed so as to exhibit the above to the meter body 12 so as to be openable and closable.
[0016]
Among these, the instrument body 12 includes a pair of opening / closing levers 16 used for opening / closing the clamp sensor 12, in addition to the liquid crystal display unit 13 for displaying the measured values digitally, the necessary operation buttons 14, the operation dial 15 and the like. 16 is provided and has an appropriate shape provided with a required structure that allows an operator to smoothly perform a measurement operation by one-hand operation.
[0017]
On the other hand, FIG. 3 is a front view showing an example of a clamp sensor according to the present invention. The flexible coil body 22 is formed by winding a winding 26 on the outer peripheral surface of a flexible tube 23 made of an insulating material . The clamp sensor 21 is formed including at least an insulating cover 41 that covers the flexible coil body 22.
[0018]
If this is demonstrated based on the example of illustration, the clamp sensor 21 is the instrument main body 12 by the one side cover part 42 and the other side cover part 45 as a resin molded product divided | segmented into 2 so that each may exhibit a substantially semicircle shape. On the other hand, a winding 26 is applied to the outer peripheral surface of an insulating cover 41 that is attached so as to be openable and closable so as to exhibit a substantially annular shape when closed, and a flexible tube 23 made of an insulating material as shown in FIG. The open end faces 23a, 23a and 23b, 23b, which are separately housed in the one side cover part 42 and the other side cover part 45 and have a corresponding positional relationship when the cover is closed, are arranged to face each other. And at least a coil body 22. However, the clamp sensor 21 is not limited to the illustrated example, for example, a flexible coil body having a predetermined length and a linear shape, and an insulating tape attached to the outer surface of the flexible coil body. Appropriate structure comprising an insulating cover formed by covering a rubber tube and capable of being fixed while deforming the clamp sensor into a substantially annular shape and bringing the open end faces located at the proximal end and the distal end into contact with each other A clamp-type ammeter can be formed by attaching to the main body of the instrument.
[0019]
FIG. 2 is an explanatory view showing an assembly process example of the flexible coil body 21 constituting the clamp sensor 21. The flexible tube 23 having a hollow portion 23c made of an insulating hollow resin material such as vinyl chloride, for example. As shown in FIG. 4A, the heat shrinkable tube 24 is attached to the base end portion 23a and the tip end portion 23b, or an insulating tape is attached or an insulating paint is applied. A large-diameter portion 25 as shown in FIG. If necessary, only the flexible tube 23 having the same diameter without providing the large diameter portion 25 may be used. The large-diameter portion 25 is integrally provided by forming the outer diameter of the base end portion 23a and the distal end portion 23b of the flexible tube 23 larger than the outer diameter of other portions. May be.
[0020]
Thereafter, a shape-retaining core material (not shown) is inserted through the hollow portion 23c around the entire circumference of the flexible tube 23 including the large-diameter portion 25, as shown in FIG. Winding 26 is applied over the entire circumference of the flexible tube 23 so that the lead wire 27 composed of the start end line portion 27a and the end end line portion 27b is positioned on the base end side. At this time, the winding 26 can be applied by increasing the number of turns only in the portion where the base end portion 23a and the distal end portion 23b of the flexible tube 23 are located compared to other portions. Thus, after the winding 26 is applied, the heat-shrinkable tubes 28 are separately attached to the windings 26 located on the proximal end side and the distal end side excluding the lead wire 27 to form the insulating sleeve portion 29. The insulating sleeve portion 29 in this case may be integrally formed by attaching a heat shrinkable tube over the entire length of the flexible tube 23 to which the winding 26 is applied.
[0021]
In this way, after forming the insulating sleeve portion 29 and removing the core material, the base end portion 23a side of the flexible tube 23 is interposed through the insulating sleeve portion 29 as shown in FIG. And an insulating cap 30 that is a resin molded product comprising a base portion 31 and a peripheral side portion 32 at the winding portion located on the side of the tip portion 23b and the base end side as shown in FIG. By connecting the external lead wires 51 and 52 separately to the starting end line portion 27a and the terminating end line portion 27b positioned as the lead wire 27, and then fixing the position by attaching the insulating tape 53 to the connecting portion. The flexible coil body 22 having a linear shape can be formed. The thickness t of the base portion 31 in the insulating cap 30 is possible from the viewpoint of minimizing the gap formed between the open end faces 22a, 22a of the flexible coil bodies 22, 22 and 22b, 22b. Although it is desirable to be as thin as possible, it is preferable to set the thickness to about 0.5 mm in consideration of the shape retention. In addition, as shown in FIG. 5, the insulating cap 30 is provided with a protrusion 35 that can be press-fitted into the hollow portion 23 c of the flexible tube 23 on the inner bottom surface 34 located inside the base portion 31. Is desirable.
[0022]
In addition, the flexible coil body 22 formed in this way is provided with a flexibility that allows the entire flexible coil body 22 to be bent and deformed. Therefore, as shown in FIG. It can be curved very easily.
[0023]
For this reason, the clamp sensor 21 divides the insulating cover 41 into two parts as shown in FIG. 3, and each of the flexible coil body 22 is divided into a first cover part 42 and a second cover part 45 each having a substantially semicircular shape. Can be formed. At this time, the base end opening 43 and the tip opening 44 of the one side cover portion 42 and the base end opening 46 and the tip opening 47 of the other side cover portion 45 are connected to the base portion 31 of the insulating cap 30. The outer end face 33 at the end is exposed as a butt end face 39.
[0024]
Moreover, in this case, the one-side cover portion 42 and the other-side cover portion 45 are each divided in half so that the face-to-face matches can be freely divided to form the flexible coil body 22 including the insulating cap 30 as if it were covered. It is desirable to form it so that it can be covered and stored. In this case, the one-side cover part 42 and the other-side cover part 45 are integrated with each other by joining and fixing the respective contact boundary parts after facing each other with an adhesive or by melting and fixing them. If this is done, it is possible to eliminate the need to attach the insulating sleeve portion 29 to the flexible coil body 22 that is necessary to ensure the required insulation.
[0025]
In this case, the insulating cap 30 and the one-side cover portion 42 and the other-side cover portion 45 where the insulating cap 30 is inscribed are mutually connected to each other so that the flexible coil body 22 can be freely positioned and accommodated. It is preferable to provide unevenness that fits. Specifically, as shown in FIG. 5, a fitting groove 36 is formed in the circumferential side portion 31 of the insulating cap 30 along the circumferential direction, and the one-side cover portion 42 and others are arranged as shown in FIG. By forming ribs 48 and 49 that can be freely fitted into the fitting groove 36 at positions corresponding to the side cover portion 45, the flexible coil bodies 22 can be positioned and stored correctly. It is desirable to do so. Further, the rib may be formed on the insulating cap 30 side, and the fitting groove may be formed on the one side cover part 42 and the other side cover part 45 side. Reference numeral 50 in FIG. 6 indicates, for example, a protrusion or a fitting hole disposed on one side by splitting the one side cover portion 42, and by fitting them with each other facing each other. Each of the one side cover part 42 and the other side cover part 45 can be correctly positioned and assembled separately.
[0026]
In the present invention, the winding 26 can be formed by aligning and winding the core wire around the flexible tube 23, and also from FIG. 4 showing a cross section in the direction of the arrows AA in FIG. As is apparent, a winding layer 26a is formed by winding a plurality of layers so as to have two or more layers, preferably three or more layers, and a winding layer 26a is formed, and each winding is cut at one or more arbitrary positions. The layer 26a may be formed by averaging the cross-sectional area.
[0027]
Further, according to the illustrated example, the termination line portion 27b of the lead wire 27 is drawn out to the proximal end side by rewinding while applying the winding 26, but if necessary, inside the hollow portion 23c of the flexible tube 23. Can be pulled out as a return line inserted from the front end side to the end side.
[0028]
Furthermore, in the present invention, the insulating cap 30 has the butt end surface 39 when the peripheral side portion 32 is curved so as to match the curvature of the one side cover portion 42 and the other side cover portion 45 and the clamp sensor 21 is closed. , 39 are preferably formed in consideration of the positional relationship of the base 31 so that they are in close contact with each other.
[0029]
Since the present invention is configured in this way, the compact clamp sensor 21 is formed by separately storing the flexible coil bodies 22 in the one-side cover portion 42 and the other-side cover portion 45. Therefore, the clamp type ammeter 11 itself can be miniaturized.
[0030]
In this case, the flexible coil body 22 constituting the clamp sensor 21 can be formed in a linear shape by applying a winding 26 to the outer peripheral surface of the flexible tube 23. As the winding machine, a general-purpose machine can be used instead of an expensive dedicated machine, and this can contribute to a reduction in product cost. In addition, since the flexible coil body 22 is provided with a flexibility that allows the entire flexible coil body 22 to be bent and deformed, the flexible coil body 22 can flexibly cope with a subsequent design change and increase the degree of freedom in design. be able to.
[0031]
Further, since the clamp sensor 21 does not require the magnetic core 3 as shown in FIG. 7, not only can the burden required for the magnetic shield measures be reduced, but also the saturation phenomenon even if the strength of the magnetic field increases. Therefore, the measurement range can be increased, and the overall weight can be reduced.
[0032]
Furthermore, in the case of utilizing the characteristics of the Rogowski coil in principle, it is usually said that it is necessary to wind by aligning the core wire around the outer periphery of the hollow core. Thus, when the winding layer 26a is formed by applying the winding 26 with multiple layers, each winding when the ring is cut at one or more arbitrary positions without being influenced by the accuracy of the automatic winding machine. Since the cross-sectional area of the line layer 26a can be averaged, it can contribute to the improvement of mass productivity.
[0033]
Further, in the case where the large diameter portion 25 is formed at the proximal end portion 23a and the distal end portion 23b of the flexible tube 23, the winding 26 positioned at the large diameter portion 25 is also increased in diameter by that amount. Output of the flexible coil bodies 22 and 22 located on the butt end surfaces 39 and 39, the base portions 31 and 31 of the insulating caps 30 and 30 having a thickness t are provided between the open end surfaces 22a and 22a. Even if a gap is formed, the influence can be made relatively small and the measurement accuracy can be improved.
[0034]
Further, when the flexible coil body 22 includes the insulating sleeve portion 29, it is possible to ensure a more preferable insulating property when the clamp sensor 21 surrounds the conductor to be measured or at the time of measurement after the enclosure. .
[0035]
Furthermore, when the terminal line portion 27b of the lead-out line 27 is drawn from the distal end side to the terminal end side in the hollow portion 23c of the flexible tube 23, it is composed of odd layers such as three layers or five layers. Even when the winding 26 is applied by multilayer winding, the termination line portion 27b as a return line can be smoothly returned to the base end side.
[0036]
Further, the insulating cover 41 is formed of a one-side cover portion 42 and an other-side cover portion 45 that are divided in half so that the face-to-face matches can be freely divided, and the peripheral side portion 31 of the insulating cap 30 has a fitting groove. 36, when the ribs 48 and 49 to be fitted to the fitting groove 36 are respectively provided at corresponding positions of the one-side cover portion 42 and the other-side cover portion 45, the flexible coil body 22 is arranged on one side. While being correctly positioned on the cover part 42 and the other side cover part 45, they can be stored separately easily.
[0037]
When the insulating cap 30 includes the protrusion 35, the insulating cap 30 can be more securely fixed to the flexible tube 23 by press-fitting the protrusion 35 into the flexible tube 23. Can do.
[0038]
【The invention's effect】
As described above, according to the present invention, a compact clamp sensor can be formed by separately storing the flexible coil bodies in the one-side cover portion and the other-side cover portion. The ammeter itself can also be miniaturized.
[0039]
In addition, since the flexible coil body can be formed linearly by winding the outer peripheral surface of the flexible tube, the automatic winding machine also contributes to a reduction in product cost by using a general-purpose machine. be able to. In addition, since flexibility is imparted to the flexible coil body, the degree of freedom in design can be increased.
[0040]
Furthermore, since the clamp sensor is coreless, not only can the burden of magnetic shield measures be reduced, but also the saturation range can be eliminated, the measurement range can be increased, and the overall weight can also be reduced. .
[0041]
On the other hand, even if the characteristics of Rogowsky coils are used in principle, if the winding layer is formed by multi-layer winding, it depends on the accuracy of the automatic winding machine. Since the cross-sectional area at an appropriate position of the winding layer can be averaged without any problem, it can contribute to the improvement of mass productivity.
[0042]
In addition, if the flexible tube has a large diameter portion, the winding can be increased in diameter to increase the output, so even if there is a gap between the butt end faces, The influence can be made relatively small to contribute to the improvement of measurement accuracy.
[0043]
Furthermore, when the flexible coil body is provided with an insulating sleeve portion, it is possible to ensure better insulation when the clamp sensor surrounds the conductor to be measured or at the time of measurement after the enclosure. Moreover, when the end line portion of the lead wire is drawn out to the end side through the hollow portion of the flexible tube, even when the winding is performed by the multi-layer winding composed of an odd number of layers, The terminal line portion as the return line can be smoothly returned to the base end side.
[0044]
Each of the one-side cover portion and the other-side cover portion is formed by being divided in half, and a fitting groove is formed in the peripheral side portion of the insulating cap between the one-side cover portion and the other-side cover portion . When the ribs are respectively provided, the flexible coil body can be accommodated very easily while being correctly positioned in the insulating cover. In this case, if the one-side cover part and the other-side cover part are integrated together by fixing the respective contact boundary parts after facing each other, it is necessary to ensure the required insulation. The structure can be simplified by eliminating the need for attaching the insulating sleeve portion. In addition, when the insulating cap is provided with a protrusion, the insulating cap can be more securely fixed to the flexible tube.
[Brief description of the drawings]
FIG. 1 is a front view illustrating a clamp-type ammeter according to the present invention with a part thereof broken away.
FIG. 2 is an explanatory view showing an assembly process example of a flexible coil body constituting a clamp sensor according to the present invention.
FIG. 3 is a front view showing an example of a clamp sensor according to the present invention.
4 is an explanatory diagram showing an enlarged cross-sectional structure in the direction of arrows AA in FIG. 3;
5 is an explanatory diagram showing an enlarged cross-sectional structure of an encircled portion taken along a dashed line in FIG.
FIG. 6 is an explanatory view showing, on an enlarged scale, a front end portion on one side of a reverse-side cover that constitutes a clamp sensor according to the present invention.
FIG. 7 is a front view showing an example of a clamp sensor constituting a conventional clamp-type ammeter.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 Clamp sensor 12 Instrument main body 13 Liquid crystal display part 14 Operation button 15 Operation dial 16 Opening / closing operation lever 21 Clamp sensor 22 Flexible coil bodies 22a and 22b Open end surface 23 Flexible tube 23a Base end part 23b Tip part 23c Hollow part 24 Heat-shrinkable tube 25 Large-diameter portion 26 Winding 26a Winding layer 27 Lead wire 27a Leading wire portion 27b Terminating wire portion 28 Heat-shrinkable tube 29 Insulating sleeve portion 30 Insulating cap 31 Base portion 32 Peripheral side portion 33 Outer end surface 34 Inner bottom surface 35 Protrusion 36 Fitting groove 39 Butting end surface 41 Insulating cover 42 One side cover portion 43 Base end opening portion 44 Front end opening portion 45 Other side cover portion 46 Base end opening portion 47 Front end opening portions 48 and 49 Rib 50 Projection or fitting hole 51 , 52 External lead wire 53 Insulation tape

Claims (11)

Insulating cover that is attached to the instrument body so that it can be opened and closed so as to exhibit a substantially annular shape when it is closed with the one side cover part and the other side cover part that are divided into two so as to exhibit a substantially semicircular shape. And an open end face that is wound separately on the outer peripheral surface of the flexible tube made of an insulating material and stored separately in the one-side cover part and the other-side cover part, and in a corresponding positional relationship when the cover is closed In a clamp sensor having at least a flexible coil body facing each other ,
The flexible coil body is applied over the entire circumference so that a flexible tube made of an insulating material and a lead line consisting of a start line end part and a terminal line part are located on the base end side of the flexible tube. clamp sensor, wherein the windings, that the insulating cap is Kutsugae設the winding site located on the proximal side and the distal side of the flexible tube is formed by at least provided. It said flexible tube, the clamp sensor according to claim 1, characterized in that it has a greater was the large diameter portion of the outer diameter than other sites and its proximal end and a distal end. The insulating cap is provided on an insulating sleeve portion formed by attaching a heat-shrinkable tube to each of windings positioned at least at the base end portion and the tip end portion excluding the lead wire of the flexible tube . The clamp sensor according to claim 1 or 2, wherein The winding clamp sensor according to any of claims 1 to 3, characterized in that the number of turns in the proximal end and a distal end and larger than the number of turns in the other sites. The clamp sensor according to any one of claims 1 to 4, wherein the terminal line portion of the lead-out line is pulled out by being inserted through the hollow portion of the flexible tube from the tip side to the terminal side . The winding is characterized by averaging the cross-sectional area of each winding layer when it is cut in one or more arbitrary positions by forming a winding layer by winding multiple layers around a flexible tube. The clamp sensor according to any one of claims 1 to 5 . The clamp sensor according to any one of claims 1 to 6, wherein the insulating caps are arranged so that the outer end surfaces of the insulating caps are in close contact with each other. The one-side cover part and the other-side cover part are each divided in half so as to be able to meet each other in a freely divided manner. The insulating cap, and the one-side cover part and the other-side cover at a part where the insulating cap is inscribed The clamp sensor according to any one of claims 1 to 7 , wherein each of the first and second portions is provided with recesses and projections that fit to each other so that the flexible coil body can be positioned and accommodated freely . The one-side cover portion and the other-side cover portion, which are each divided in half and freely formed to meet each other, are fixed to each other by fixing the respective contact boundary portions after the face-to-face matching. The clamp sensor according to claim 8, which is integrated . The clamp sensor according to any one of claims 1 to 9 , wherein the insulating cap is provided with a protrusion on the inner bottom surface thereof that can be freely press-fitted into the hollow portion of the flexible tube . A clamp-type ammeter comprising the clamp sensor according to claim 1 .

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