JP6628574B2 - Current sensor - Google Patents

Description

  The present invention relates to a technique relating to a current sensor capable of enhancing a shielding effect against an external magnetic field or an electric field and stably maintaining a fixed position between sensor heads to improve measurement accuracy.

  As disclosed in Patent Document 1, for example, a clamp-type ammeter includes a current sensor that detects a current flowing in a conductor to be measured by enabling clamping to the conductor to be measured in a live state. Is formed.

Japanese Patent No. 4459567

  FIGS. 5 and 6 (a) and (b) are descriptions in which the clamp sensor (current sensor) shown in FIGS. 5 is an exploded perspective view of the entirety, FIG. 6A is a longitudinal sectional view taken along the line BB in FIG. 6B, and FIG. FIG. 6B is a longitudinal sectional view taken along the line AA in FIG. 6A.

  According to these figures, the current sensor 111 is surrounded by a magnetic core 121 composed of one core portion 117 and the other core portion 127, and forms a clamp measurement window 112 which can be opened and closed between the cores. It is composed of one sensor head 113 (positioned on the upper side in the illustrated example) and the other sensor head 123 (positioned on the lower side in the illustrated example), into which the measurement conductor L is freely introduced.

  Of these, one sensor head 113 has one shield case 114 having a space 118 in one outer case part 115 and containing one inner case part 116, and a pair of butted end faces 117a, 117a. A gap is formed to expose one of the core portions 117 fixedly disposed in the one inner case portion 116 and the other inner case portion 116 to regulate the accommodating position of the one inner case portion 116 in the one outer case portion 115 so as to conduct each other. The clamp 118 includes one pair of spacers 119 and 119 made of a non-magnetic and conductive material and one partition 120 that defines the upper surface of the clamp measurement window 112.

  As shown in FIGS. 6A and 6B, the one core portion 117 has an arrangement relationship in which the surface height of the pair of abutting end surfaces 117a, 117a substantially matches the open end surface 116a of the one inner case portion 116. It is exposed under the condition, and is housed in a state where one of the inner case portions 116 is filled with an injection resin material (not shown) and fixed in position.

  On the other hand, the other sensor head 123 has a gap 128 in the other outer case portion 125 and accommodates the other inner case portion 126 with the other shield case 124 and a pair of butted end surfaces 127a, 127a. The other core portion 127 fixedly arranged in the other inner case portion 126 by exposing the second inner case portion 126 and a gap for restricting the accommodation position of the other inner case portion 126 in the other outer case portion 125 so as to conduct each other. It is composed of the other pair of spacers 129 and 129 made of a non-magnetic and conductive material interposed in 128 and the other partition 130 that defines the lower surface of the clamp measurement window 112.

  The other core portion 127 has an arrangement relationship in which the surface height of the pair of butted end surfaces 127a, 127a substantially matches the open end surface 126a of the other inner case portion 126, as shown in FIGS. The other inner case portion 126 is exposed and filled with an injectable resin material (not shown) so as to be fixed in position.

  In other words, the current sensor 111 of Patent Literature 1 has one pair of spacers 119, 119 made of non-magnetic material and the other pair of spacers 129, 129 interposed therebetween, so that one shield case is used for measurement. The one inner case part 116 forming the other part 114 and the other inner case part 126 forming the other shield case 124 are placed under a positional relationship in which their open end faces 116a and 126a face each other. , It is possible to ensure a shielding effect against an external magnetic field or electric field.

  Further, one pair of spacers 119, 119 connects one outer case 115 and one inner case 116, and the other pair of spacers 129, 129 connects the other outer case 125 and the other inner case. 126 can be effectively electrically connected to each other, whereby the effect of external noise such as common mode noise can be effectively suppressed.

  On the other hand, FIG. 7 is an explanatory view schematically showing a conventional example in which a connector is added to the current sensor shown in FIGS. 5 and 6, in which (a) corresponds to FIG. FIG. 7B is an explanatory view showing the spacer on the other sensor head side without illustration, FIG. 7B is an explanatory view showing the one sensor head side, and FIG. (D) shows an explanatory view of a state in which the arrangement relationship between the connector and one of the core portions is viewed from the top side.

  According to the figure, the current sensor 111 is surrounded by a magnetic core 121 comprising one core portion 117 and the other core portion 127, and forms a clamp measurement window 112 which can be opened and closed between each other, and is not shown. It is composed of one sensor head 113 and the other sensor head 123 that can freely combine the conductor to be measured. In FIG. 7, the same members as those in FIGS. 5 and 6 are denoted by the same reference numerals, and detailed description thereof will be omitted.

  In the example shown in FIGS. 7A and 7B, a connector 131 is interposed between one core portion 117 and one inner case portion 116. The connector 121 is necessary to connect one core portion 117 to a reference potential in order to reduce the influence (CMRR) of the conductor L under test due to the common mode voltage as shown in FIG. The arrangement relationship of the connector 121 with respect to the core portion 117 is such that as shown in FIG. 7D, a small rectangle is arranged at the center of the top surface of one of the core portions 117.

  Meanwhile, in the conventional type current sensor 111 shown in FIGS. 5 to 7, one of the sensor heads 113 that constitutes one of the sensor heads 113 while improving the influence (CMRR) of the conductor L to be measured due to the common mode voltage is improved. In order to prevent the magnetic permeability between the core 117 and the one shield case 114 and the magnetic permeability between the other core 127 and the other shield case 124 from decreasing, respectively, the one core 117 In addition, it is necessary to inject a resin material and fix the position in such a manner that stress is not applied as much as possible to each storage member in each space area around the other core portion 127.

  In particular, when a thermosetting insulating resin material containing an epoxy resin material is used as the resin material to be injected, if it is exposed to a high-temperature environment or a high-temperature, high-humidity environment even once, the shrinkage and expansion that occur during the curing process Since there is a characteristic that even when the state is returned to normal temperature, it does not return to the state before the environmental change, the one sensor head 113 is configured while improving the influence (CMRR) of the conductor L to be measured due to the common mode voltage. It is necessary to perform the injection so that the magnetic permeability between the one core portion 117 and the one shield case 114 and the magnetic permeability between the other core portion 127 and the other shield case 124 do not decrease. is there.

  However, such characteristics at the time of shrinkage and expansion generated during the curing process after the injection of the thermosetting insulating resin material including the epoxy resin material are caused by the generated stress that the one inner case portion 116 is moved to the one outer case portion 115 by the generated stress. In the inner case part 126 and the other inner case part 126 is moved in the other outer case part 125, so that the butt end face 117a on the one sensor head 113 side and the butt end face 127a on the other sensor head 123 side are moved. Is also changed.

  As a result, as an example of a sensor head of a certain current sensor, for example, when the variation of one core portion of the magnetic core is about 5 μm and the height variation of the inner case portion of one shield case is about 2 μm Even when the measured value is 1% rdg. It has been pointed out that there is a problem that cannot be ignored.

  That is, in the sensor heads 113 and 123 of the conventional type current sensor 111 shown in FIGS. 5 to 7, the contraction / expansion that occurs during the curing process of the thermosetting insulating resin material including the injected epoxy resin material is prevented. The resulting stress causes fluctuations in the positions of the core portions 117 and 127 constituting the magnetic core 121 and in the heights and positions of the inner case portions 116 and 126 in the shield cases 114 and 124. There was a disadvantage that the measured values would be out of order.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art when a thermosetting insulating resin material including an epoxy resin material is used as a resin material to be injected. It is an object of the present invention to provide a current sensor capable of improving the current.

Means for Solving the Problems The present invention has been made to achieve the above object, and a first invention of the present invention is surrounded by a magnetic core consisting of a pair of cores arranged so as to bring the butted end faces into direct contact with each other, and forming a closable clamp measurement window therebetween, comprising a set of sensor heads freely combined introduction of the measurement conductor, each of these sensor heads, internal to secure voids in the outer case case And a core case that is fixedly housed in the inner case portion by exposing the butted end face, and restricting a housing position of the inner case portion in the outer case portion. A pair of spacers interposed in the gap to conduct both, a partition portion defining the clamp measurement window, and the magnetic core side disposed on one of the core portions; E Bei a connector to be connected to a reference potential, at least one of the sensor head, by injecting a thermosetting insulating resin material so as to position fixing the housing member including the core portion in the sensor head, the heat In a current sensor provided with a stress coping means for regulating an action direction in which a fixed position on the core portion side is changed by a stress caused by expansion and contraction generated in a curing process after injecting a curable insulating resin material. The most main feature is that the stress coping means is formed by the connector provided with a surface size equal to or greater than the surface facing the inner case portion side of the core portion on the side provided with the connector. Features.

According to a second aspect of the present invention, there is provided a clamp measuring window which is surrounded by a magnetic core comprising a pair of core portions arranged so as to bring the butted end faces into direct contact with each other, and which is openable and closable between the magnetic cores. It comprises a set of sensor heads that are freely combined with the introduction of conductors, and each of these sensor heads has a shield case accommodating the inner case portion by securing a gap in the outer case portion, and exposing the butting end surface. And a pair of spacers interposed and disposed in the gap so that the core portion is fixedly accommodated in the inner case portion and accommodates the inner case portion in the outer case portion while controlling the accommodation position of the inner case portion. And a partition portion defining the clamp measurement window, and at least a connector disposed on one of the core portions and connecting the magnetic core side to a reference potential, In a current sensor in which a thermosetting insulating resin material is injected into the sensor head and a storage member including the core is fixed in position, at least one of the sensor heads includes the core and the inner case. And between the inner case portion and the outer case portion, to prevent the thermosetting insulating resin material from entering at least one side, thereby reducing the amount of heat to be injected. A stress coping means is provided for restricting the direction of action of stress at the time of expansion and contraction generated during the curing process after injecting the curable insulating resin material to a direction other than the core portion or the inner case portion. The most important feature .

In the second invention, the stress coping means is disposed in a space region between the inner case portion and the core portion, and adjusts a direction of stress acting upon expansion and contraction of the thermosetting insulating resin material to the core. A non-magnetic inner partitioning member that regulates in a direction other than the portion, and a stress at the time of expansion and contraction of the thermosetting insulating resin material arranged in a space region between the inner case portion and the outer case portion. It may be formed of a non-magnetic outer partition member that regulates the action direction to a direction other than the inner case portion.

  In this case, the non-magnetic inner partitioning material and the non-magnetic outer partitioning material each have a substantially U-shape or a substantially box-like shape, and are preferably arranged with a portion other than the opening face positioned in the core direction. preferable.

  Further, the non-magnetic inner partition member is a horizontal plate portion extending from one end surface side to the other end surface side in the longitudinal direction of the inner case portion in a state interposed between the connector and the inner case portion. And a conductive inner partition plate having a substantially T-shape comprising an inner weir plate portion reaching the vicinity of the core portion orthogonally to the surface direction of the horizontal plate portion, and the non-magnetic outer partition material is A horizontal plate portion extending from the open end side of the spacer to a corresponding portion side in the longitudinal direction of the outer case portion, and orthogonal to a surface direction of the horizontal plate portion, to the vicinity of the other end surface side of the inner case portion. And a conductive outer partition plate formed by an outer weir plate portion reaching the outer partition wall. In this case, the horizontal plate portion forming the conductive outer partition plate may be formed integrally with the spacer.

According to the first aspect of the present invention , at least one of the sensor heads has at least one of a sensor head and a stress generated during expansion and contraction generated in a curing process after the thermosetting insulating resin material is injected. By providing a stress countermeasure for preventing an action of changing the fixed position on the core portion side, the stress generated at the time of expansion and contraction generated during the curing process of the thermosetting insulating resin material is reduced. Therefore, it is possible to provide a high-precision current sensor having a shielding effect against an external magnetic field or an electric field by eliminating a factor that causes a change in a fixed position on the core portion side.

Moreover, the stress coping means Runode is formed by a connector with an opposing surface and equal or greater surface size of the inner casing portion is interposed by applying in the core portion of the side having the connector, the core portion and the inner casing section By preventing the thermosetting insulating resin material from entering the gap between the core and the inner case, the stress that changes the position of the butted end faces of the core parts and the position of the butted end faces of the inner case parts is reduced. The effect from the action can be reduced. In addition, the connector used has a larger surface size than the conventional connector.As a result, the resistance between the core and the reference potential is reduced while securing a large electrical contact area. It is also possible to reduce the degree of being affected by the mode voltage (CMRR).

According to the invention described in claim 2 (second invention) , at least one of the sensor heads has at least one of the sensor heads, between the core part and the inner case part, and the inner case part. After the thermosetting insulating resin material is injected while preventing the thermosetting insulating resin material from entering at least one side between the outer case portion and the outer case portion while reducing the injection amount. There is provided a stress countermeasure for restricting the direction of action of stress at the time of expansion and contraction generated during the hardening process to a direction other than the core portion or the inner case portion. And between the inner case part and the outer case part, while reducing the injection amount of the thermosetting insulating resin material to at least one side, during the curing process after the injection of the thermosetting insulating resin material How stress acts during expansion and contraction Can be restricted to a direction other than the core portion or the inner case portion, so that the influence of the stress acting to change the position of the butted end surfaces of the core portions and the position of the butted end surfaces of the inner case portions can be reduced. be able to. In addition, according to the third aspect of the present invention, the stress coping means includes the non-magnetic inner partition member disposed in the space between the inner case portion and the core portion, and the inner case portion and the outer case portion. Since it is formed with the non-magnetic outer partitioning material placed in the space area between the two, it is possible to reduce the volume of the thermosetting insulating resin material and to inject it. The direction of stress during shrinkage is restricted to a direction other than the core and the inner case to reduce the effect of stress acting to displace the position of the butted end faces of the core parts and the position of the butted end faces of the inner case parts. be able to.

  According to the invention described in claim 4, the non-magnetic inner partition member and the non-magnetic outer partition member in claim 3 both have a substantially U-shape or a substantially box-like shape, and each of the non-magnetic inner partition member and the non-magnetic outer partition member has a portion other than the opening surface in the core portion direction. Since the parts are located and positioned, the space area between the inner case part and the core part is through the non-magnetic inner partition material, and the space area between the inner case part and the outer case part is the non-magnetic outer part. By dividing and reducing the volume of the thermosetting insulating resin material in each space region via the partition member, the influence of the stress action can be reduced. In addition, since the opening surfaces of the non-magnetic inner partition member and the non-magnetic outer partition member are arranged in a direction different from the direction of the core portion, the stress generated when the thermosetting insulating resin material expands and contracts. Can be restricted to a direction other than the core portion.

  According to the invention described in claim 5, the non-magnetic inner partition member is a conductive inner partition plate having a horizontal plate portion and an inner dam plate portion, and the non-magnetic outer partition member is a horizontal plate portion and an outer dam plate. And a space region between the inner case portion and the core portion is the inner dam plate portion of the conductive inner partition plate, and the inner case portion and the outer case portion. The space between them is the outer weir plate part of the conductive outer partition plate, which separates and reduces the volume of each, and reduces the effects of the stress generated when the thermosetting insulating resin material expands and contracts. Can be avoided.

  According to the sixth aspect of the present invention, since the horizontal plate portion forming the conductive outer partition plate of the fifth aspect is formed integrally with the spacer, the member configuration of the stress handling means can be simplified accordingly. In addition, the operation of arranging the stress handling means can be further simplified.

FIG. 8 is an explanatory diagram schematically showing the same configuration as that of the conventional example shown in FIG. 7 with different reference numerals attached thereto in order to clarify the positional relationship between members in the overall configuration example of the present invention. It is explanatory drawing which shows an example of the 1st invention of this invention typically, (a) is explanatory drawing corresponding to FIG.7 (b), (b) is FIG.2 (a) 2 (c) is an explanatory view of the arrangement of the connector and one of the cores in FIG. 2 (b) as viewed from the top side. Explanatory drawing showing an example of the second invention of the present invention in correspondence with FIG. FIG. 4 is an explanatory view showing a modification of the second invention shown in FIG. 3. FIG. 6 is an exploded perspective view of the entire configuration of a conventional example. 6A and 6B are explanatory views showing the arrangement relationship of the conventional example shown in FIG. 5, in which FIG. 6A is a longitudinal sectional view taken along line BB in FIG. 6B, and FIG. (A) is a longitudinal sectional view taken along the line AA in FIG. FIG. 7 is an explanatory view schematically showing another conventional example in which a connector is added to the current sensor shown in FIGS. 5 and 6, wherein (a) corresponds to FIG. 6 (a) and one of the sensor heads; FIG. 7 (b) is an explanatory view showing the one side of the sensor head when one outer case part is removed in FIG. 7 (a), and FIG. FIG. 7B is an explanatory view of the state viewed from the bottom side, and FIG. 7D is an explanatory view of the arrangement relation between the connector and one core portion viewed from the top side.

  Prior to the description of the present invention, FIG. 1 is given the same reference numerals as in the conventional example shown in FIG. FIG.

As shown in the figure, the current sensor 11 according to the present invention includes a magnetic core 21 composed of a pair of core portions 17 and 27 arranged so as to bring the butting end surfaces 17a and 27a in a positional relationship corresponding to the close measurement into direct contact. It is surrounded by, and forms a closable clamp measurement window 12 therebetween, comprising a set of sensor heads 13 and 23 to be combined freely introduction of measured conductor L as shown FIG ing. Reference numerals 35 and 36 in FIG. 1 denote spatial regions into which a thermosetting insulating resin material such as an epoxy resin material is injected in one sensor head 13, and reference numerals 37 and 38 denote epoxy regions in the other sensor head 23. The space region into which a thermosetting insulating resin material such as a resin material is injected is shown.

  Each of the sensor heads 13 and 23 has a space 18 and 28 in the outer case portions 15 and 25 made of a high-permeability alloy material such as a permalloy material, and is made of a high-permeability alloy material such as a permalloy material. Shield cases 14 and 24 accommodating the inner case sections 16 and 26, and core sections 17 and 27 that are fixedly accommodated in the inner case sections 16 and 26 by exposing the respective butting end faces 17a and 27a. And a non-magnetic material such as bronze, copper, or aluminum interposed in the respective gaps 18 and 28 so as to make a surface contact with the inner case portions 16 and 26 in the outer case portions 15 and 25 while regulating the housing position. And a spacer 19 made of a conductive metal material (a spacer on the other sensor head 23 side is not shown), partition walls 20 and 30 defining the clamp measurement window 12, and a magnetic field. (A) In order to connect the 21 side to the reference potential, between any one of the core portions 17 and 27 and the inner case portions 16 and 26, and between the one core portion 17 located on the upper side and the one inner case portion 16 in the illustrated example. And a connector 31 arranged at least. The connector 31 is formed so as to allow electrical conduction between the core portion 17 and the inner case portion 16 by, for example, winding a conductive metal wire around a sponge-like foam. Have been.

Hereinafter, a case where the present invention is applied to one sensor head 13 located on the upper side in FIG. 1 will be described as an example. Incidentally, FIG. 2, an example of the first aspect of the present invention, FIG. 3, an example of a second invention of the present invention, FIG. 4, the second invention shown in FIG. 3 It is explanatory drawing which showed the modification of each typically.

  In the present invention, at least one of the sensor heads, in the illustrated example, the sensor head 13 provided with the connector 31 located on the upper side is in a curing process after injecting a thermosetting insulating resin material (not shown) including an epoxy resin material. By providing a stress coping means 41 for preventing an effect of changing a fixed position on one core portion 17 side by a stress generated due to the generated expansion and contraction, the core portion 17 and the inner case portion which are storage members are provided. It is formed so as to be able to suppress the subsequent position fluctuation of the sixteen.

Here, it will be described in more detail an example of the first invention shown in FIG. 2, stress coping means 41, intended to be formed by applying a change in shape of the connector 31 itself one of the sensor head 13 is provided is there. That is, the connector 31 (stress handling means 41) interposed between the inner case part 16 and the one core part 17 arranged via the spacer 31 in the one outer case part 15 An opposing surface 31a having a surface size equal to or larger than the top surface size is provided and formed.

  As a result of the provision of such a shape and size, the connector 31 has an epoxy between the core portion 17 and the inner case portion 16 at two locations shown as surrounding regions A and B indicated by thick broken lines in FIG. It is possible to prevent the thermosetting insulating resin material such as a resin material from entering and to reduce the amount of the resin material to be injected, which is generated in the curing process after the thermosetting insulating resin material is injected into the space region 35. It is possible to add a function as a stress coping unit 41 that can reduce a factor that fluctuates due to the influence of stress caused by expansion / contraction on the core 17 side.

  That is, a thermosetting insulating resin material such as an epoxy resin material having a large linear expansion is prevented from entering the connector 31 (stress coping means 41) between the one core portion 17 and the one inner case portion 16. As a result, by reducing the injection amount of the thermosetting insulating resin material, it is possible to alleviate the adverse effect of stress due to a temperature change or the like. As a result, the butt end face 17a on one sensor head 13 side shown in FIG. And the displacement between the butting end face 27a of the sensor head 23 and the butting end face of the inner case part 16 and the butting end face of the other inner case part 26 are reduced. Can be reduced.

  Moreover, as the connector 31 (stress handling means 41), a connector having a larger surface size than the connector 131 shown in FIG. 7 is used. As a result, the resistance between the core portion 17 and the reference potential can be increased while ensuring a large electrical contact area. By reducing the value, the degree of influence (CMRR) of the conductor L under test due to the common mode voltage as shown in FIG. 6 can be reduced.

Next, an example of the second invention of the present invention will be described in detail . At least one of the pair of sensor heads 13 and 23, and in the example shown in FIG. 17 and the inner case portion 16 and between the inner case portion 16 and the outer case portion 15 are prevented from entering the thermosetting insulating resin material into at least one side to reduce the injection amount. A stress coping means for restricting the direction of expansion and contraction stress generated in a curing process after injecting the thermosetting insulating resin material into a direction other than the core portion or the inner case portion. 41 are provided. This will be described in more detail with reference to FIG. 3. The stress countermeasure means 41 is disposed in the space region 35 between the one inner case part 16 and the one core part 17 and is made of a thermosetting material such as an epoxy resin material. A non-magnetic inner partitioning member 42 for reducing the volume of injection of the conductive insulating resin material and for controlling the direction of action of stress caused by expansion and contraction occurring during the curing process after injection, and an inner case. Similarly, when the thermosetting insulating resin material is disposed in the space region 36 between the portion 16 and the outer case portion 15 and the thermosetting insulating resin material is injected, the injection amount can be reduced . It is formed of a non-magnetic outer partition member 46 that regulates the direction of action of stress generated during expansion and contraction.

That is, according to an example of the second invention shown in FIG. 3, the non-magnetic inner partition member 42 (stress coping means 41) having a substantially U-shape or a substantially box shape is provided in the space region 35 of the one inner case portion 16. Is divided into a surrounding area indicated by a bold dashed line shown as Gothic European character A in FIG. 3 and a surrounding area indicated by a bold dashed line indicated as Gothic European character B, and And a portion other than the opening surface 42a.

For this reason, the stress generated at the time of expansion and contraction generated in the hardening process after the thermosetting insulating resin material is injected into one inner case portion 16 with reduced volume is applied to the nonmagnetic inner partition member 42 (stress handling means 41). through it or disturb so as not to act on one of the core portion 17 side, so that it is possible or direction regulating the arrow Y ₁ direction shown in FIG.

  The non-magnetic outer partition member 46 (stress coping means 41), which also has a substantially U-shape or a substantially box-like shape, has a space region 36 of one outer case portion 15 shown as Gothic European character C in FIG. Is divided into a surrounding area indicated by a thick dashed line and a surrounding area indicated by a thick dashed line indicated by the Gothic European character D, and other than the opening surface 46a in the direction of one inner case portion 16 (one core portion 17). Is positioned and positioned.

For this reason, the stress generated at the time of expansion and contraction generated during the hardening process after the volumetric injection of the thermosetting insulating resin material into the space region 36 of the one outer case portion 15 is caused by the non-magnetic outer partition member 46 (stress management). means 41) through one of the inner case portion 16 side, or interfere so as not to act on the thus one core portion 17 side, that can be or direction regulating the arrow Y ₂ direction indicated in FIG. Become.

On the other hand, according to the modified example of the second invention shown in FIG. 4, the non-magnetic inner partition member 42 is disposed in the longitudinal direction of the inner case 16 while being interposed between the connector 31 and one of the inner cases 16. Plate portion 44 extending from one side end surface 16a side to the other side end surface 16b side in the direction, and an inner weir plate portion 45 orthogonal to the horizontal direction of the horizontal plate portion 44 and approaching one of the core portions 17. Are formed as a substantially T-shaped conductive inner partition plate 43 (stress coping means 41).

  In other words, the conductive inner partition plate 43 (non-magnetic inner partition member 42) having a substantially T-shape is formed such that the space region 35 of the one inner case portion 16 has a large width shown as Gothic European character A in FIG. It is divided into a surrounding region indicated by a broken line and a surrounding region indicated by a thick dashed line shown as Gothic European character B, and is arranged such that a portion other than the opening surface 44a is positioned in the direction of one core portion 17. Become.

For this reason, the stress generated at the time of expansion and contraction generated during the hardening process after the volumetric injection of the thermosetting insulating resin material into the space region 35 of the one inner case portion 16 is caused by the conductive property of the nonmagnetic inner partition member 42. or interfere so as not to act on one of the core portion 17 side through the sexual inner partition plate 43 (stress coping means 41), so that it is possible or direction regulating the arrow Y ₁ direction shown in FIG. .

  In addition, the non-magnetic outer partition member 46 (stress handling means 41) is provided at a corresponding portion in the longitudinal direction of one outer case portion 15 from the open end 19a side of one spacer 19 (the left side in the outer case portion 15 in FIG. 4). The horizontal plate portion 48 reaching not the one end surface 15a located on the right side but the other end surface 15b) located on the right side, and the other side of one of the inner case portions 16 orthogonal to the surface direction of the horizontal plate portion 48 It is formed as a substantially L-shaped conductive outer partition plate 47 (stress handling means 41) composed of an outer weir plate portion 49 reaching the vicinity of the end face 16b side.

  That is, the conductive outer partition plate 47 (non-magnetic outer partition member 46) having a substantially L-shape is formed such that the space region 36 of the one outer case portion 15 has a large width shown as Gothic European character C in FIG. It is divided into a surrounding region indicated by a broken line and a surrounding region indicated by a thick broken line indicated by the Gothic European character D, and is arranged such that a portion other than the opening surface 46a is positioned in the direction of one core portion 17. Become.

For this reason, the stress generated at the time of expansion and contraction generated in the hardening process after the volumetric injection of the thermosetting insulating resin material into the space region 36 of the one outer case portion 15 is caused by the conductive as the nonmagnetic outer partition member 46. sex outer partition plate 47 (stress coping means 41) one of the inner case portion 16 via a or interfere so as not to act on the thus one core portion 17 side, direction and regulation of the arrow Y ₂ direction indicated in FIG. You can do that. The horizontal plate portion 48 constituting the conductive outer partition plate 47 is not shown, but can be formed integrally with one of the spacers 19.

Since the present invention is configured in this manner, at least one of the sensor heads, in the illustrated example the sensor head 13 on the side provided with the connector 31 located on the upper side, reduces the volume of the thermosetting insulating resin material by injection. By providing a stress coping means 41 for preventing an action of changing a fixed position on at least one of the core portions 17 by a stress generated at the time of expansion and contraction generated in a hardening process after the heat hardening process, the thermosetting Since the stress generated at the time of expansion and contraction generated during the curing process of the insulating resin material can be prevented through the stress coping means 41, the external magnetic field can be eliminated by eliminating the factor causing the fixed position on the core portion 16 side to fluctuate. And a highly accurate current sensor 11 having a shielding effect against electric fields.

That is, according to the first invention shown in FIG. 2, the stress handling means 41 is provided on the opposing surface 31 a having a surface size equal to or greater than the top surface of the inner case portion 16 in the core portion 17 on the side provided with the connector 31. Can be formed with a connector 31 having the same as shown in FIG. 2 (b), which is between the core portion 17 and the inner case portion 16 and is indicated by surrounding regions A and B indicated by thick broken lines. At two locations, a thermosetting insulating resin material such as an epoxy resin material is prevented from entering between the core portion 17 and the inner case portion 16 to reduce the amount of injection, thereby reducing the amount of injection between the core portions 17 and 27. It is possible to reduce the influence from the stress action that fluctuates the positions of the butting end surfaces 17a and 27a and the positions of the butting end surfaces of the inner case portions 16 and 26.

  As the connector 31, a connector having a larger surface size than the conventional connector 131 shown in FIG. 7 is used. As a result, the resistance between one core portion 17 and the reference potential can be increased while securing a large electrical contact area. By reducing this, the degree of influence (CMRR) of the conductor to be measured L due to the common mode voltage as shown in FIG. 6 can be reduced.

According to the second invention shown in FIG. 3, at least one of the sensor heads 13 includes a portion between the core portion 17 and the inner case portion 16 and a portion between the inner case portion 16 and the outer case portion 15. At the time of expansion / shrinkage occurring in the curing process after the thermosetting insulating resin material is injected while preventing the thermosetting insulating resin material from entering at least one side and reducing the injection amount. Since the stress countermeasure means 41 is provided for restricting the acting direction of the stress to a direction other than the core portion 17 or the inner case portion 16, the space between the core portion 17 and the inner case portion 16 and between the core case 17 and the inner case portion 16 are provided. The volume of the thermosetting insulating resin material injected into at least one side between the outer case portion 15 and the outer case portion 15 is reduced, and the expansion and shrinkage generated in the curing process after the thermosetting insulating resin material is injected. The action direction of the stress at the time of contraction Or, it can be restricted to a direction other than the inner case part 16, so that the position of the butted end faces 17a and 27a of the core parts 17 and 27 and the position of the butted end faces of the inner case parts 16 and 26 are changed. The effect from the stress action can be reduced.
In addition, according to the third aspect of the present invention, the stress coping means includes the non-magnetic inner partition member disposed in the space between the inner case portion and the core portion, and the inner case portion and the outer case portion. Since it is formed with the non-magnetic outer partitioning material placed in the space area between the two, it is possible to reduce the volume of the thermosetting insulating resin material and to inject it. The direction of stress during shrinkage is restricted to a direction other than the core and the inner case to reduce the effect of stress acting to displace the position of the butted end faces of the core parts and the position of the butted end faces of the inner case parts. be able to. At this time, as shown in FIG. 3 , the stress handling means 41 includes a non-magnetic inner partition member 42 disposed in the space region 35 between the one inner case portion 16 and the one core portion 17 and the one inner case portion. If it is formed by a non-magnetic outer partition member 46 disposed in the space region 36 between one of the outer casing section 15 and section 16, generated in the curing process of the thermosetting insulating resin material expands and The stress direction at the time of contraction is restricted to a direction other than the core portion 17 and the inner case portion 16 so that the positions of the butted end surfaces 17a and 27a of the core portions 17 and 27 shown in FIG. It is possible to reduce the influence from the stress action that displaces the position of the butt end face.

That is, both the non-magnetic inner partition member 42 constituting the stress corresponding unit 41 and the non-magnetic outer partition member 46 has a substantially U-shaped or substantially box-shaped, one of the core portions 17 a direction to the opening surface 42a, 46a if it is arranged to position the portion other than the gothic European letters a space region 35 in FIG. 3 by a non-magnetic inner partition member 42 between one of the inner case 16 and one of the core portion 17 A space region between one inner case portion 16 and one outer case portion 15 is surrounded by a thick region surrounded by a thick broken line and a surrounding region formed by a thick broken line shown as Gothic European character B. Numeral 36 designates a nonmagnetic outer partition member 46 which divides a surrounding area indicated by a thick dashed line shown as Gothic European character C in FIG. Doing, it is possible to pleasure not affected by the stress and volume reducing the injection amount of the thermosetting insulating resin material made of an epoxy resin acting.

The opening surfaces 42a, 46a of the non-magnetic inner partition member 42 and the non-magnetic outer partition member 46 are directed in directions different from the direction of the one core portion 17, for example, toward the other sensor head 23 shown in FIG. FIG. 3 shows that one of the core portions 17 and one of the inner case portions 16 are not affected by the stress effect generated when the thermosetting insulating resin material such as an epoxy resin material expands and contracts. It is possible to escape in the directions indicated by arrows Y ₁ and Y ₂ .

Further, according to the modified example of the second invention shown in FIG. 4, the non-magnetic inner partition member 43 is a conductive inner partition plate 43 having a horizontal plate portion 44 and an inner weir plate portion 45 as a non-magnetic outer partition member. Since each of the members 46 is formed as a conductive outer partition plate 47 having a horizontal plate portion 48 and an outer dam plate portion 49, a space region between one inner case portion 16 and one core portion 17 is formed. Reference numeral 35 denotes an inner dam plate portion 49 of the conductive inner partition plate 47, and a space region 36 between the one inner case portion 16 and the one outer case portion 15 is an outer dam plate portion 49 of the conductive outer partition plate 47. The core portion 17 and the inner case portion 16 can be prevented from being affected by the stress generated when the thermosetting insulating resin material expands and contracts while dividing and reducing the volume.

The surrounding area B in the space area 35 between the one core part 17 and the one inner case part 16 is formed by using the inner weir plate part 45 as a guide plate and the one inner case part 16 and the one outer case part 15. The surrounding area D in the space area 36 between the outer peripheral wall and the outer peripheral wall is made to function as a guide plate by using the outer dam plate portion 49 as a guide plate, so that a thermosetting insulating resin material such as an epoxy resin material can be expanded and contracted during the curing process. 4 can be released in the directions of the arrows Y ₁ and Y ₂ shown in FIG. 4 so that the side of the one core portion 17 and the side of the one inner case portion 16 are not affected by the resulting stress action.

Further, in the modification of the second invention shown in FIG. 4, when the horizontal plate portion 48 constituting the conductive outer partition plate 46 is formed integrally with the spacer 19 (not shown), the stress is reduced accordingly. The member configuration of the means 41 can be simplified, and the work of arranging the stress handling means 41 can be further simplified.

The above has been a description of the present invention based on the illustrated example, and the specific structure is not limited to this. That is, according to the example of the first invention shown in FIG. 2, since the example in which the connector 31 is arranged on one sensor head 13 side is shown, the stress countermeasure means 41 is also arranged on one sensor head 13 side. However, when the connector 31 is disposed on the other sensor head 23 side shown in FIG. 1, the stress handling means 41 is also disposed on the other sensor head 23 side.

DESCRIPTION OF SYMBOLS 11 Current sensor 12 Clamp measurement window 13, 23 Sensor head 14, 24 Shield case 15, 25 Outer case part 15a One side end surface 15b Other side end surface 16, 26 Inner case part 16a One side end surface 16b Other side end surface 17, 27 Core part 17a, 27a Butt end face 18, 28 Air gap
DESCRIPTION OF SYMBOLS 19 Spacer 19a Open end 20,30 Partition part 21 Magnetic core 31 Connector 31a Opposing surface 35,36,37,38 Space area 41 Stress handling means 42 Non-magnetic inner partitioning material 42a Opening surface 43 Conductive inner partitioning plate 44 Horizontal plate portion 44a One end 44b Other end 45 Inner dam 46 Non-magnetic outer partition 46a Opening surface 47 Conductive outer divider 48 Horizontal plate 48a One end 48b Other end 49 Outer dam

Claims (6)

It is surrounded by a magnetic core consisting of a pair of core parts arranged to bring the butted end faces into direct contact with each other, and forms a clamp measurement window that can be opened and closed between them so that the conductor to be measured can be freely combined. A set of sensor heads, each of these sensor heads having a gap in the outer case to accommodate the inner case and a shield case in which the butted end surface is exposed and fixed in the inner case. And a pair of spacers interposed in the gap so as to conduct the two while regulating the storage position of the inner case part in the outer case part, and the clamp measurement window. a partition wall for forming, e Bei a connector for connecting said magnetic core side to a reference potential is disposed on either one of the core portion, at least one of said sensor head , By injecting a thermosetting insulating resin material in the sensor head in order to position fixing the housing member including the core portion, the expansion and contraction that occur curing process after injection of the thermosetting insulating resin material In a current sensor provided with stress coping means for regulating an action direction in which the fixed position on the core portion side is changed by the generated stress,
Wherein the stress coping means is formed by the connector interposed by providing a surface size equal to or greater than a surface facing the inner case portion side of the core portion on the side including the connector. Sensors. It is surrounded by a magnetic core consisting of a pair of core parts arranged to bring the butted end faces into direct contact with each other, and forms a clamp measurement window that can be opened and closed between them so that the conductor to be measured can be freely combined. A set of sensor heads, each of these sensor heads having a gap in the outer case to accommodate the inner case and a shield case in which the butted end surface is exposed and fixed in the inner case. And a pair of spacers interposed in the gap so as to conduct the two while regulating the storage position of the inner case part in the outer case part, and the clamp measurement window. And at least one connector disposed on one of the core portions to connect the magnetic core side to a reference potential. In the current sensor formed by a position fixing the housing member including the core portion by injecting a thermosetting insulating resin material within,
In at least one of the sensor heads, the thermosetting insulating resin material to at least one side between the core portion and the inner case portion and between the inner case portion and the outer case portion The action direction of the stress at the time of expansion and contraction generated in the curing process after injecting the thermosetting insulating resin material while preventing the intrusion of the core and reducing the injection amount is changed to a direction other than the core portion or the inner case portion. A current sensor comprising a stress coping means for regulating the direction of the current sensor. The stress coping means is disposed in a space region between the inner case portion and the core portion, and shifts the direction of action of stress at the time of expansion and contraction of the thermosetting insulating resin material to a direction other than the core portion. And a non-magnetic inner partitioning member that regulates the direction of action of stress at the time of expansion and contraction of the thermosetting insulating resin material disposed in a space region between the inner case portion and the outer case portion. 3. The current sensor according to claim 2, wherein the current sensor is formed of a non-magnetic outer partition member that restricts the direction other than the case portion. The non-magnetic inner partition member and the non-magnetic outer partition member each have a substantially U-shape or a substantially box-like shape, and are arranged so that a portion other than the opening surface is located in the core direction. Current sensor. The non-magnetic inner partition member, a horizontal plate portion extending from one end surface side to the other end surface side in the longitudinal direction of the inner case portion in a state interposed between the connector and the inner case portion, A conductive inner partition plate having a substantially T-shape comprising an inner weir plate portion reaching the vicinity of the core portion orthogonal to the surface direction of the horizontal plate portion,
The non-magnetic outer partition member has a horizontal plate portion extending from the open end side of the spacer to a corresponding portion side in the longitudinal direction of the outer case portion, and an inner case portion orthogonal to the surface direction of the horizontal plate portion. 4. The current sensor according to claim 3, wherein the current sensor is a conductive outer partition plate formed by the outer weir plate portion reaching the vicinity of the other end surface side. 5. The current sensor according to claim 5, wherein the horizontal plate portion forming the conductive outer partition plate is formed integrally with the spacer.

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