JP2019168405A - Sensor head and current sensor - Google Patents

Abstract

To provide an excitation core, a sensor head, and a current sensor which can employ a thin-band magnetic body as an excitation core of a division clamp type.SOLUTION: A reinforcement body 3A1 is formed of two parts of a first reinforcement member 3A11 and a second reinforcement member 3A12, which are made of a non-magnetic material. The first reinforcement member 3A11 and the second reinforcement member 3A12 are provided with a hinge part 3A13 in the respective one ends of the first and second reinforcement members. The hinge part 3A13 makes both ends of the reinforcement body 3A1 freely contact with each other or separate from each other. Both ends of the reinforcement body 3A1 overlap with each other in the thickness direction when they become close to each other. A thin-band magnetic body 3A2 is formed on the reinforcement body 3A1 and both ends of the thin-band magnetic body 3A2 overlap with each other in the thickness direction.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a sensor head and a current sensor.

  As the above-described current sensor, for example, a through-type non-contact current sensor described in Patent Document 1 is known. The current sensor described in Patent Literature 1 has a current to be measured flowing by passing an object to be measured through an annular exciting core and measuring current and voltage flowing in an exciting coil wound around the exciting core. Is measuring.

  As a current measurement method, a flux gate type current detection method for obtaining a current signal from a current or voltage flowing in an exciting coil is known. Furthermore, a zero flux method is also known in which a current signal at that time is passed through a feedback coil wound outside the exciting coil, and a current signal is obtained from the current flowing through the feedback coil.

  As the above-described excitation core, it is conceivable to use a ribbon-like magnetic material such as amorphous in order to improve performance and reduce costs. In such a case, generally, a method is adopted in which an exciting core is formed by overlapping several layers in such a manner that the ribbon-like magnetic body is wound a plurality of times.

JP 2007-057294 A

  However, such an excitation core cannot be used in a split clamp type non-contact current sensor. This is because if the excitation core composed of the thin ribbon-like magnetic material is divided, the performance as the excitation core is lost. The first factor is a mechanical strength problem. When the exciting core around which the ribbon-like magnetic body is wound is divided, the cross-section has only a few layers of the ribbon-like magnetic body, and the cross-section of each layer is linear. For this reason, when it is used in a split clamp type non-contact current sensor, the mechanical strength of the ribbon-shaped magnetic material cannot withstand the opening / closing operation, causing a problem that contact failure occurs immediately.

  The second factor is the problem of reproducibility of the current measurement value. Since there are only a few layers of linear magnetic material in the cross section of the excitation core divided as described above, the cross-section portion is used in the opening / closing operation of the clamp portion of the divided clamp type non-contact current sensor employing this. The contact between the magnetic bodies is substantially a line contact. This means that the contact area between the magnetic bodies is small. In such a case, since it becomes difficult to obtain the reproducibility of the magnetic coupling at the contact portion accompanying the opening and closing of the clamp portion, a problem that the reproducibility of the current measurement value cannot be obtained as a result also occurs.

  Under such circumstances, there has been a problem that it is not possible to employ a thin strip-like magnetic body for the excitation core structure of the split clamp type non-contact current sensor.

  The present invention has been made in view of the above background, and an object of the present invention is to provide a sensor head and a current sensor that can employ a ribbon magnetic body as a split clamp type excitation core.

  In order to solve the above-described problems, a sensor head according to the present invention includes a reinforcing body made of a non-magnetic material and having both ends overlapped in the thickness direction and formed in a circular shape, and provided on the reinforcing body. A belt-like magnetic body that is formed in a circular shape by being stacked in the thickness direction, and by opening and closing the reinforcing body about an axis parallel to the central axis of the circular reinforcing body, In the sensor head in which both end portions of the belt-like magnetic body are detachable, the axis is a straight line passing through both ends and the center of the belt-like magnetic body in a state where both ends of the belt-like magnetic body are overlapped. It is provided in the position shifted | deviated from.

  The sensor head of the present invention includes a first reinforcing member and a second reinforcing member which are made of a non-magnetic material and whose both ends are overlapped in the thickness direction to form a circle, and the first reinforcing member and the first reinforcing member. The first reinforcing member having a circular shape, the first reinforcing member having a first belt-like magnetic body and a second belt-like magnetic body which are provided on the two reinforcing members and are formed in a circular shape by overlapping both end portions in the thickness direction. And opening and closing the first reinforcing member and the second reinforcing member about an axis parallel to the central axis of the second reinforcing member, thereby allowing the first belt-shaped magnetic body and the second belt-shaped magnetic body to be opened and closed. In the sensor head in which both ends can be contacted / separated, the shaft has both ends and the first band-shaped magnetic in a state where both ends of the first band-shaped magnetic body and the second band-shaped magnetic body are overlapped with each other. Provided at a position deviated from a straight line passing through the body and the center of the second belt-like magnetic body. It is characterized in that is.

  In addition, the sensor head of the present invention includes a reinforcing body made of a non-magnetic material and having both ends overlapped in the thickness direction and formed in a circular shape, and provided on the reinforcing body, with both ends overlapping in the thickness direction. A belt-like magnetic body formed in a circular shape, and by opening and closing the reinforcing body about an axis parallel to the central axis of the circular reinforcing body, both ends of the belt-like magnetic body In the sensor head in which the part can be contacted and separated, the reinforcing body is formed such that an intermediate portion between both end portions of the reinforcing body is formed along a circle, and the both end portions are separated from the circle formed by the intermediate portion. It is formed as follows.

  The sensor head of the present invention includes a first reinforcing member and a second reinforcing member which are made of a non-magnetic material and whose both ends are overlapped in the thickness direction to form a circle, and the first reinforcing member and the first reinforcing member. The first reinforcing member having a circular shape, the first reinforcing member having a first belt-like magnetic body and a second belt-like magnetic body which are provided on the two reinforcing members and are formed in a circular shape by overlapping both end portions in the thickness direction. And by opening and closing the first reinforcing member and the second reinforcing member about an axis parallel to the central axis of the second reinforcing member, both ends of the first belt-like magnetic body and the second belt-like magnetic body In the sensor head in which the portions can be contacted and separated, each of the first reinforcing member and the second reinforcing member has an intermediate portion between both ends of the first reinforcing member and the second reinforcing member along a circle. Formed, and the both end portions deviate from the circle formed by the intermediate portion. Characterized in that it is formed as.

  Moreover, you may further provide the elastic member which urges | biases the both ends of the said strip | belt-shaped magnetic body mutually.

  Moreover, you may further provide the elastic member which urges | biases the both ends of the said 1st strip | belt-shaped magnetic body and the said 2nd strip | belt-shaped magnetic body mutually.

  In addition, a current sensor according to the present invention includes the above-described sensor head, and a current detection unit that detects a current flowing through the measurement target that has penetrated the sensor head.

  According to the above-described invention, both end portions of the belt-like magnetic body are overlapped and contacted in the thickness direction. As a result, a sufficient contact area can be maintained for the opening / closing operation of the strip-shaped magnetic body, and thus a thin strip-shaped magnetic body can be employed as a clamp-type excitation core.

  Further, according to the above-described invention, both end portions of the first belt-like magnetic body and the second belt-like magnetic body are overlapped and contacted in the thickness direction. Accordingly, a sufficient contact area can be maintained for the opening / closing operation of the first belt-shaped magnetic body and the second belt-shaped magnetic body, and thus a thin strip-shaped magnetic body can be employed as the split clamp type excitation core.

It is a block diagram which shows the non-contact-type current sensor of this invention in 1st Embodiment. It is an AA line schematic sectional drawing of the sensor head of FIG. It is a perspective view of the exciting core shown in FIG. 1 at the time of clamping. FIG. 4 is a side view of the excitation core shown in FIG. 3. It is a schematic side view of the exciting core shown in FIG. 1 at the time of clamping. It is a schematic side view of the exciting core shown in FIG. 1 at the time of non-clamping. It is a schematic side view of the exciting core at the time of clamping in the 1st modification of 1st Embodiment. It is a schematic side view of the exciting core at the time of unclamping in the 1st modification of 1st Embodiment. It is a side view of the exciting core at the time of clamping in a 2nd embodiment. FIG. 10 is a schematic side view of the excitation core shown in FIG. 9. It is a side view of the excitation core in the modification of 2nd Embodiment. It is a side view of the excitation core in the modification of 2nd Embodiment. It is a side view of the excitation core in the modification of 2nd Embodiment. It is a schematic side view of the reinforcement body at the time of the clamp in 2nd Embodiment. It is a schematic side view of the reinforcement body shown in FIG. 14 at the time of non-clamping. It is a schematic side view of the exciting core at the time of clamping in the second embodiment. It is a schematic side view of the exciting core shown in FIG. 16 at the time of non-clamping. It is a schematic side view of the exciting core at the time of clamping in the modification of 2nd Embodiment. It is a schematic side view of the excitation core shown in FIG. 18 at the time of non-clamping. It is a side view of the reinforcement body at the time of the clamp in the modification of 2nd Embodiment. It is a side view of the reinforcement body shown in FIG. 20 at the time of non-clamping. It is a side view of the reinforcement body at the time of the clamp in the modification of 2nd Embodiment. It is a side view of the reinforcement body shown in FIG. 22 at the time of non-clamping. It is a block diagram which shows the non-contact-type current sensor of this invention in 3rd Embodiment. It is a disassembled perspective view of the reinforcement body which comprises the excitation core shown in FIG. It is a disassembled perspective view of the excitation core shown in FIG. FIG. 27 is a schematic side view of the excitation core shown in FIG. 26 during clamping. FIG. 27 is a schematic side view of the excitation core shown in FIG. 26 during unclamping. FIG. 25 is a perspective view of the sensor head shown in FIG. 24 when not clamped. FIG. 25 is a side view of the sensor head shown in FIG. 24 when not clamped. FIG. 25 is a perspective view of the sensor head shown in FIG. 24 during clamping. It is a schematic side view of the excitation core in the modification of 3rd Embodiment. It is a perspective view of the sensor head which has the excitation core of FIG. 32 at the time of non-clamping. It is a side view of the sensor head which has the excitation core of FIG. 32 at the time of non-clamping. FIG. 33 is a perspective view of a sensor head having the excitation core of FIG. 32 at the time of clamping. Containment It is a schematic side view of the excitation core in 4th Embodiment. It is a schematic side view of the excitation core in the modification of 4th Embodiment. It is a fragmentary sectional view of the exciting core at the time of unclamping in the modification of 1st-4th embodiment. It is a fragmentary sectional view of the exciting core shown in FIG. 38 at the time of clamping. It is a fragmentary sectional view of the exciting core at the time of unclamping in the modification of 1st-4th embodiment. It is a fragmentary sectional view of the exciting core shown in FIG. 38 at the time of clamping.

(First embodiment)
An embodiment of a non-contact current sensor in the first embodiment will be described with reference to the drawings. In FIG. 1, the feedback coil 8 shows a state in which only a part of the core portions 20L and 20R is wound in order to avoid complication of the drawing, but actually, the feedback coil 8 is along the circumferential direction of the core portions 20L and 20R. It is common to wind the whole.

  The current sensor 1 includes a sensor head 2 and a current detection circuit 10 as current detection means. As shown in FIGS. 1 and 2, the sensor head 2 includes an annular excitation core 3A, an excitation coil 4 wound around the excitation core 3A, and a magnetic current collector provided inside and outside the excitation core 3A. An inner magnetic collector 5 and an outer magnetic collector 6, as well as a housing case 7 (see FIGS. 29 to 31) for housing these exciting core 3A, exciting coil 4, inner magnetic collector 5 and outer magnetic collector 6, and housing case 7 And a feedback coil 8 wound around. An object to be measured 9 such as an electric wire is passed through the center of the exciting core 3A.

  The current detection circuit 10 includes an excitation circuit 11, a detection circuit 12, an LPF circuit 13, an amplification circuit 14, a feedback circuit 15, and an I / V circuit 16. The excitation coil 4 is connected to the excitation circuit 11 and is excited in an alternating manner by an alternating current excitation current. The exciting voltage or exciting current of the exciting coil 4 changes due to the action of a current flowing through the object 9 to be measured (hereinafter, current to be measured). The detection circuit 12 detects a change in the excitation voltage or excitation current and passes the LPF circuit 13 to obtain a signal proportional to the current to be measured.

  Subsequently, this signal is amplified by the amplifier circuit 14 to generate a current flowing through the feedback coil 8 via the feedback circuit 15. A magnetic field is generated inside the feedback coil 8 by the current flowing through the feedback coil 8, and as a result, magnetic flux is generated in the exciting core 3 </ b> A, the inner magnetic collector 5, and the outer magnetic collector 6. The direction of winding of the feedback coil 8 is such that the magnetic flux generated by the current flowing through the feedback coil 8 acts to cancel the magnetic flux generated by the current to be measured. Therefore, with this configuration, the magnetic fluxes of the exciting core 3A, the inner magnetic collector 5 and the outer magnetic collector 6 inside the feedback coil 8 become substantially zero, and the current flowing through the feedback coil 8 is proportional to the current to be measured. Is converted into a current voltage by the I / V circuit 16 to obtain an output voltage which is a final estimated value of the current to be measured.

  Next, the configuration of the excitation core 3A will be described below with reference to FIGS. The exciting core 3A includes a reinforcing body 3A1 and a strip-shaped magnetic body 3A2. The reinforcing body 3A1 is made of a strip-like nonmagnetic material (for example, plastic), and both ends thereof are overlapped in the thickness direction and formed in an annular shape. The reinforcing body 3A1 is composed of a first reinforcing member 3A11 and a second reinforcing member 3A12 that are formed of separate parts. The first reinforcing member 3A11 and the second reinforcing member 3A12 are each formed in a substantially U shape along a circle. A hinge portion 3A13 is provided at one end T11 and T21 of the first reinforcing member 3A11 and the second reinforcing member 3A12.

  The hinge portion 3A13 includes a shaft portion 3A14 as a shaft provided at one end portion T21 of the second reinforcing member 3A12 and a bearing portion 3A15 provided at one end portion T11 of the first reinforcing member 3A11. The shaft portion 3A14 is provided in a substantially cylindrical shape, and protrudes from the end surface of the one end portion T21 of the second reinforcing member 3A12 so that the axial direction thereof is parallel to the central axis of the annular reinforcing body 3A1. The bearing portion 3A15 is formed in a concave shape on the end surface of the one end portion T11 of the first reinforcing member 3A11, and the shaft portion 3A14 is inserted therein. Accordingly, the first reinforcing member 3A11 and the second reinforcing member 3A12 are rotatable about the shaft portion 3A14, and the other end portions T12 and T22 are contactable and away from the shaft portion 3A14.

  The other end portions T12 and T22 of the first reinforcing member 3A11 and the second reinforcing member 3A12 correspond to both end portions of the reinforcing body 3A1, and when approached, they are overlapped in the thickness direction as shown in FIG. In the present embodiment, the inner surface of the other end portion T22 of the second reinforcing member 3A12 is overlaid on the outer surface of the other end portion T12 of the first reinforcing member 3A11. Hereinafter, the state in which the other end portions T12 and T22 of the first reinforcing member 3A11 and the second reinforcing member 3A12 are overlapped in the thickness direction to form the annular exciting core 3A is referred to as “clamp” or “closed”. The state in which the other end portions T12 and T22 of the first reinforcing member 3A11 and the second reinforcing member 3A12 are separated is referred to as “unclamped” or “open”.

  The second reinforcing member 3A12 is provided with a step 3A17 in the middle thereof. The other end portion T22 side of the step portion 3A17 of the second reinforcing member 3A12 protrudes outside the annular shape with respect to the one end portion T21 rather than the step portion 3A17 of the first reinforcing member 3A11 and the second reinforcing member 3A12. Is provided. That is, the first reinforcing member 3A11 and the one end T21 side of the stepped portion 3A17 of the second reinforcing member 3A12 are provided along a circle having the same diameter. On the other hand, the other end T22 side of the stepped portion 3A17 of the second reinforcing member 3A12 is along a circle having a larger diameter than the stepped portion 3A17 of the first reinforcing member 3A11 or the second reinforcing member 3A12. Is provided.

  In the present embodiment, the inner surface on the other end T22 side of the stepped portion 3A17 of the second reinforcing member 3A12, the outer surface of the first reinforcing member 3A11, and the outer surface on the one end T21 side of the stepped portion 3A17 of the second reinforcing member 3A12 Are provided along a circle having the same diameter. And in this level | step-difference part 3A17, through-hole 3A16 penetrated along the periphery of a cyclic | annular form is provided. The through hole 3A16 is provided in a long rectangular shape along the width direction of the reinforcing body 3A1.

  The strip-shaped magnetic body 3A2 is made of a soft magnetic material, and has a thin strip shape (ribbon shape) with a thickness of 100 μm or less, for example, and has flexibility. The strip-shaped magnetic body 3A2 is provided across both ends of the reinforcing body 3A1. The band-shaped magnetic body 3A2 passes through the through-hole 3A16, the second reinforcing member 3A12 on the inner surface of the second reinforcing member 3A12 on the other end T22 side than the stepped portion 3A17, and the first reinforcing member 3A12 on the one end T21 side from the stepped portion 3A17. The reinforcing member 3A11 is provided on the outer surface of the reinforcing member 3A11.

  More specifically, the belt-like magnetic body 3A2 is passed through the through hole 3A16, one end T31 thereof is provided on the outer surface of the other end T12 of the first reinforcing member 3A11, and the other end T32 is provided on the second reinforcing member 3A12. It is provided on the inner surface of the other end T22. Thereby, as shown in FIG. 4, when both end portions of the reinforcing body 3A1 (that is, the other end portions T12 and T22 of the first reinforcing member 3A11 and the second reinforcing member 3A12) are overlapped, both ends of the band-shaped magnetic body 3A2 are also Contact in the thickness direction.

  According to the excitation core 3A described above, both ends T31 and T32 of the strip-shaped magnetic body 3A2 can be made contactable and separable by making the reinforcing body 3A1 openable and closable around the shaft 3A14.

Next, the position of the shaft portion 3A14 will be described in detail. Shank 3A14, as shown in FIG. 5, in a state where both end portions of the band-shaped magnetic member 3A2 are stacked, shifted from on the line L ₁ passing through the center O ₁ of the strip magnetic 3A2 both ends an annular position Is provided.

In this embodiment, the shaft portion 3A14 is a on a circle reinforcement 3A1 is formed, from a position A on the straight line _{L 1} and the other end portion T22 of the second reinforcing member 3A12, and than the step portion 3A17 The second reinforcing member 3A12 is provided on the side away from the other end T22. For this reason, the length from the one end T21 to the other end T22 of the second reinforcing member 3A12 is shorter than the length from the one end T11 to the other end T12 of the first reinforcing member 3A11.

  As shown in FIG. 1, the inner magnetic collector 5 includes a first inner magnetic collector 51 serving as a first magnetic collector divided into two and a second inner magnetic collector 52 serving as a second magnetic collector. The first inner magnet collector 51 is disposed inside the first reinforcing member 3A11, and the second inner magnet collector 52 is disposed inside the second reinforcing member 3A12. The first inner magnetic collector 51 and the second inner magnetic collector 52 are provided in a strip shape, and are formed in a substantially U shape so that both ends in the longitudinal direction are opposed to each other in the thickness direction. The inner magnetism collector 5 is formed in an annular shape by contacting both ends of the first inner magnetism collector 51 and the second inner magnetism collector 52.

  The outer magnetic collector 6 includes a first outer magnetic collector 61 as a first magnetic collector divided into two and a second outer magnetic collector 62 as a second magnetic collector. The first outer magnetic collector 61 is disposed outside the first reinforcing member 3A11, and the second outer magnetic collector 62 is disposed outside the second reinforcing member 3A12. The first outer magnetic current collector 61 and the second outer magnetic current collector 62 are provided in a strip shape, and are formed in a substantially U shape so that both ends in the longitudinal direction face each other. The outer magnet collector 6 is formed in a circular ring shape by contacting both ends of the first outer magnet collector 61 and the second outer magnet collector 62.

  Further, the first reinforcing member 3A11, the band-shaped magnetic body 3A2 on the first reinforcing member 3A11, the first inner magnetic collector 51, and the first outer magnetic collector 61 constitute the left core portion 20L, and the second reinforcing member 3A12, The strip-shaped magnetic body 3A2, the second inner magnet collector 52, and the second outer magnet collector 62 on the second reinforcing member 3A12 constitute the right core portion 20R.

  The housing case 7 is equivalent to a third embodiment shown in FIGS. 29 to 31 to be described later. As shown in the figure, the housing case 7 is composed of a first case portion 71 and a second case portion 72 that are formed of different parts. Each of the first case portion 71 and the second case portion 72 is formed in a rectangular tube shape, and the tube length direction is formed in a substantially U shape along a circle. The first reinforcing member 3A11 is accommodated and fixed in the first case portion 71, and the second reinforcing member 3A12 is accommodated and fixed in the second case portion 72.

  According to the above configuration, as shown in FIG. 6, the first reinforcing member 3A11 and the second reinforcing member are centered on the shaft portion 3A14 so as to separate the two end portions T12 and T22 that are overlapped in the thickness direction of the reinforcing body 3A1. The member 3A12 is rotated. Thereby, both ends T12 and T22 of the reinforcing body 3A1 and both ends T31 and T32 of the strip-shaped magnetic body 3A2 provided on the reinforcing body 3A1 are separated from each other to be in an unclamped state. At this time, the first inner magnet collector 51, the second inner magnet collector 52, the first outer magnet collector 61, and the second outer magnet collector 62 are opposite to each other so that both ends thereof allow movement of the reinforcing body 3A1. Leave. After that, after passing the object 9 to be measured from the gap between both ends T12, T22 of the separated reinforcing body 3A1, the first reinforcing member centering on the shaft portion 3A14 so as to bring both ends T12, T22 of the reinforcing body 3A1 closer to each other. When the 3A11 and the second reinforcing member 3A12 are rotated, as shown in FIGS. 3 to 5, both end portions T12 and T22 of the reinforcing body 3A1 and both end portions T31 and T32 of the strip-shaped magnetic body 3A2 are overlapped in the thickness direction. Clamped.

  According to the first embodiment described above, both end portions T31 and T32 of the strip-shaped magnetic body 3A2 are overlapped and contacted in the thickness direction. Accordingly, a sufficient contact area can be maintained for the opening / closing operation of the strip-shaped magnetic body 3A2, and thus the thin strip-shaped magnetic body 3A2 can be employed as the clamp-type excitation core 3A. Moreover, since the location where the strip-shaped magnetic body 3A2 contacts is one location, it is only necessary to improve the contact at only one location, and the sensor performance can be easily maintained.

  In addition, according to the first embodiment, the strip-shaped magnetic body 3A2 is formed in an annular shape by overlapping both end portions T12 and T22 in the thickness direction, and the both end portions T12 and T22 can be contacted and separated. It is provided on the body 3A1. Thereby, even if it is flexible strip | belt-shaped magnetic body 3A2, since a shape can be maintained, mechanical strength can be aimed at, without affecting the characteristic of excitation core 3A.

Further, according to the first embodiment, the shaft portion 3A14 is, in a state where both end portions T31, T32 of the strip magnetic 3A2 is superposed passes through the center _{O 1} of the both end portions T31, T32 and strip magnetic 3A2 It is provided at a position displaced from the straight line L _1. Thereby, when both ends T12 and T22 of the reinforcing body 3A1 are clamped close to each other, it is possible to reduce the friction between the both ends T31 and T32 of the strip-shaped magnetic body 3A2.

In detail, providing the shaft portion 3A14 to position A (FIG. 5) through the straight line _{L 1,} the reinforcing member 3A1 is for rotation around the position A, first, the other end of the second reinforcing member 3A11,3A12 The parts T12 and T22 approach each other so as to rub. For this reason, both end portions (contact surfaces) of the strip-shaped magnetic body 3A2 are worn and the surface state changes. As a result, there is a fear that the measured values vary, the reproducibility of the measured values is lowered, and the sensor characteristics are lowered. Further, when the sensor head 2 is clamped, it is necessary to exceed the frictional force, and the operability when the sensor head 2 is clamped may be lowered.

  According to the first embodiment described above, it is possible to suppress the other end portions T12 and T22 of the first and second reinforcing members 3A11 and 3A12 from rubbing and approaching each other. Decrease and operability can be suppressed.

  Further, according to the first embodiment, the strip-shaped magnetic body 3A2 is passed through the through hole 3A16, and one end T31 thereof is on the outer surface of the other end T12 of the first reinforcing member 3A11 (= one end of the reinforcing body 3A1). The other end T32 is provided on the inner surface of the other end T22 of the second reinforcing member 3A12 (= the other end of the reinforcing body 3A1). Accordingly, the band-shaped magnetic body 3A2 can be supported simply by providing the reinforcing body 3A1 with the through holes 3A16 so that both end portions of the band-shaped magnetic body 3A2 overlap in the thickness direction.

  Further, according to the first embodiment, the reinforcing body 3A1 is provided with the step portion 3A17. Further, the other end T22 side of the step part 3A17 of the second reinforcing member 3A12 protrudes outside the annular shape with respect to the one end part T21 side of the step part 3A17 of the first reinforcing member 3A11 and the second reinforcing member 3A12. Is provided. A through hole 3A16 is formed in the stepped portion 3A17. Thereby, even if it passes the strip | belt-shaped magnetic body 3A2 through the through-hole 3A16, it can prevent that it deform | transforms and can aim at the improvement of the characteristic of the excitation core 3A.

  Further, the inner surface on the other end T22 side of the stepped portion 3A17 of the second reinforcing member 3A12 is the same as the outer surface of the first reinforcing member 3A11 and the outer surface on the one end T21 side of the stepped portion 3A17 of the second reinforcing member 3A12. It is provided along a circle of diameter. Thereby, the shape of the strip-shaped magnetic body 3A2 can be kept circular even through the through hole 3A16.

  In addition, according to the first embodiment, the reinforcing body 3A1 includes the first reinforcing member 3A11 and the second reinforcing member 3A12 that are configured as separate parts, and one end portions of the first reinforcing member 3A11 and the second reinforcing member 3A12. T11 and T21 are provided with a hinge portion 3A13, which is attached to be openable and closable around a shaft portion 3A14. The other end portions T12 and T22 of the first reinforcing member 3A11 and the second reinforcing member 3A12 are stacked in the thickness direction. It has been. Thereby, it can be set as the structure which hold | maintains strip | belt-shaped magnetic body 3A2 with a simple structure, and opens and closes the both ends.

In addition, according to 1st Embodiment mentioned above, although axial part 3A14 was provided on the circle | round | yen which reinforcing body 3A1 forms, it is not restricted to this. The shaft portion 3A14, may be provided on a position displaced from the straight line L _1, as shown in FIGS. 7 and 8 may be provided on the outside of a circle reinforcement 3A1 shaft portion 3A14 is formed. In this case, if one end portions T11 and T21 of the first reinforcing member 3A11 and the second reinforcing member 3A12 are provided with projecting portions 3A15 and 3A16 projecting outside the ring, and the hinge portions 3A13 are provided on the projecting portions 3A15 and 3A16. Good. In addition, the reinforcing body 3A1 is provided with the hinge portion provided in the housing case 7 in which the first reinforcing member 3A11 and the second reinforcing member 3A12 are accommodated without providing the hinge portion 3A13 in the first reinforcing member 3A11 and the second reinforcing member 3A12. It may be provided outside the circle to be formed.

(Second Embodiment)
Next, a non-contact current sensor according to a second embodiment will be described with reference to the drawings. The difference between the first embodiment and the second embodiment is the configuration of the exciting core 3B, and the current detection circuit 10 is the same as that of the first embodiment, and thus detailed description thereof is omitted here.

As shown in FIG. 9, the exciting core 3B includes a reinforcing body 3B1 and a strip-shaped magnetic body 3B2. The difference between the reinforcing body 3A1 of the first embodiment and the reinforcing body 3B1 of the second embodiment is the position of the shaft portion 3B14 (hinge portion 3B13). In the first embodiment, as shown in FIG. 5, the shaft portion 3A14 is configured such that both end portions T31 and T32 of the strip-shaped magnetic body 3A2 are overlapped with each other and the center of the annular strip-shaped magnetic body 3A2. is provided at a position shifted from on the line L ₁ passing through O _1. In contrast, in the second embodiment, the hinge portion 3B13 (the shaft portion 3B14 and the bearing portion 3B15) has both end portions T31 and T32 of the belt-like magnetic body 3B2 overlapped as shown in FIG. It is provided on the straight line _{L 1} passing through the center _{O 1} of the section T31, T32 and annular band magnetic body 3B2.

  The difference between the reinforcing body 3A1 of the first embodiment and the reinforcing body 3B1 of the second embodiment is the shapes of both end portions T12 and T22 of the reinforcing body 3B1. In the first embodiment, both ends T12 and T22 of the reinforcing body 3A1 are provided along a circle. In the second embodiment, both ends T12 and T22 of the reinforcing body 3B1 are as shown in FIG. , So as to be out of the circle formed by the intermediate part between the two end parts T12, T22.

  In the present embodiment, one end (the other end T12) of both ends T12 and T22 of the reinforcing body 3B1 is bent inward from the circle and is formed along a straight line. The other (other end T22) is bent outward from the circle and is formed along a straight line. The strip-shaped magnetic body 2B2 is disposed on the reinforcing body 3B1.

  According to the second embodiment described above, both end portions T12 and T22 of the reinforcing body 3B1 are formed so as to deviate from the circle formed by the intermediate portion between both end portions T12 and T22, as shown in FIG. ing. Even if comprised in this way, when both ends T12 and T22 of reinforcement body 3B1 are clamped close, it can reduce that both ends T31 and T32 of strip | belt-shaped magnetic body 3B2 rub against each other.

Incidentally, according to the second embodiment, the shaft portion 3B14 reinforcing member 3B1, which had been provided on the straight line L _1, not limited to this. Shank 3B14 reinforcing member 3B1, as shown in FIG. 11, similarly to the first embodiment, may be a position shifted from on the line L _1, provided outside of the circle reinforcement 3B1 forms May be.

  Further, according to the second embodiment, the end portion T12 of the reinforcing body 3B1 is bent inward from the circle formed by the reinforcing body 3B1, and the end portion T22 is bent outward from the circle, thereby both end portions T12 of the reinforcing body 3B1. , T22 is set off the circle, but is not limited to this. Both end portions T12 and T22 of the reinforcing body 3B1 may have a shape that is off the circle and overlaps with each other in the thickness direction. For example, the reinforcing bodies 3B1 may be formed like the reinforcing bodies 3C1 and 3D1 shown in FIGS. Good. Both ends T12 and T22 of the reinforcing body 3C1 shown in FIG. 12 are bent inward from the circle. The reinforcing body 3D1 shown in FIG. 12 has both end portions T12 and T22 bent outward from the circle.

By the way, in 2nd Embodiment mentioned above, as shown to FIG.14 and FIG.15, two points on the outer surface of 1st reinforcement member 3B11 and 2nd reinforcement member 3B12 which pinched | interposed hinge part 3B13 are set to A, B, and inside Two points on the side are A ′ and B ′. The distance between the two points A and B at the time of clamping is L _CAB and the distance between the two points A ′ and B ′ is L _CA′B ′ (see FIG. 14). the distance _{L OAB,} 2 points A', the distance between the B'and _{L OA'B'} (see FIG. 15). The following inequalities (1) and (2) hold for these distances.
L _CAB > L _OAB (1)
L _{CA′B ′} <L _{OA′B ′} (2)

  That is, when the belt-like magnetic body 3B2 is provided on the outer surface of the hinge portion 3B13 and the shaft portion 3B14 is provided between the inner surface and the outer surface of the reinforcing body 3B1, the above formulas (1) and (2) are established. As a result, as shown in FIG. 17, a deformation (deflection) D that does not follow the reinforcing body 3B1 occurs in the belt-like magnetic body 3B2 during unclamping. However, as shown in FIG. 16, at the time of clamping, the belt-like magnetic body 3B2 is arranged along the reinforcing body 3B1, and deformation (deflection) D does not occur. Thereby, the shape of strip | belt-shaped magnetic body 3B2 can be made symmetrical at the time of clamping. For this reason, it becomes strong to the position shift from the center of the strip | belt-shaped magnetic body 3B2 of the to-be-measured object 9, and the influence of an external magnetic field, and can improve sensor performance. 14 to 17 described above and FIGS. 18 to 23 described below, the stepped portion 3B17 is omitted for the sake of simplicity.

  Further, according to the first and second embodiments described above, the stepped portions 3A17 and 3B17 are provided in the reinforcing bodies 3A1 and 3B1, but the present invention is not limited to this. The step portions 3A17 and 3B17 are not essential, and through holes along the radial direction may be provided in the reinforcing bodies 3A1 and 3B1.

  Further, according to the first and second embodiments described above, the strip-shaped magnetic bodies 3A2 and 3A2 are provided on the outer surfaces of the hinge portions 3A13 and 3B13. However, as shown in FIGS. 18 and 19, the hinge portion 3B13 is provided. A belt-like magnetic body 3B2 may be provided on the inner surface of the substrate. In this case, the through hole is provided in the first reinforcing member 3B11.

  Further, according to the first and second embodiments described above, the shaft portions 3A14 and 3B14 are provided between the inner surface and the outer surface of the reinforcing bodies 3A1 and 3A2. However, the present invention is not limited to this. As shown in FIG.20 and FIG.21, you may provide axial part 3B14 on the outer side rather than the annular ring which reinforcement body 3B1 forms.

Moreover, as shown in FIG.22 and FIG.23, you may provide axial part 3B14 inside the annular ring which reinforcement body 3B1 forms. In this case, the following inequalities (3) and (4) hold for the distances L _CAB, L _{CA′B ′,} L _{OAB, and} L _OA′B ′.
L _CAB > L _OAB (3)
L _{CA′B ′} > L _{OA′B ′} (4)

  In this case, even if the belt-like magnetic body 3B2 is provided on the outer surface or the inner surface of the one end portions T11 and T21 of the first reinforcing member 3B11 and the second reinforcing member 3B12, the deformation D occurs at the time of non-clamping. D does not occur.

  In the first and second embodiments described above, the excitation cores 3A and 3B are described as one example. However, the present invention is not limited to this. A plurality of exciting cores 3A and 3B may be arranged in the band width direction, and the object to be measured 9 may be passed through the centers of the plurality of exciting cores 3A and 3B. In this case, the detection circuit 12 adds the excitation voltage or excitation current of the excitation coil 4 wound around each excitation core 3A, 3B, and passes the LPF circuit 13.

(Third embodiment)
Next, an embodiment of a non-contact type current sensor in the third embodiment will be described based on the drawings. The current sensor 1 includes a sensor head 2 and a current detection circuit 10. The difference between the first embodiment and the third embodiment is the configuration of the sensor head 2, and the current detection circuit 10 is the same as that of the first embodiment, and therefore detailed description thereof is omitted here.

  As shown in FIG. 24 and the like, the sensor head 2 includes an annular excitation core 3E, an excitation coil 4 wound around the excitation core 3E, an inner magnetic collector 5 provided inside and outside the excitation core 3E, and The outer magnetic collector 6, a housing case 7 (FIGS. 29 to 31) that houses the exciting core 3 </ b> E, the exciting coil 4, the inner magnetic collector 5, and the outer magnetic collector 6, and a feedback coil 8 wound around the housing case 7 And. Since the exciting coil 4, the inner magnetic body 5, the outer magnetic body 6, and the feedback coil 8 are substantially the same as those in the first embodiment, detailed description thereof is omitted here.

  Next, the configuration of the excitation core 3E will be described below with reference to FIGS. The exciting core 3E includes a reinforcing body 3E1, a first strip-shaped magnetic body 3E2, and a second strip-shaped magnetic body 3E3. The reinforcing body 3E1 includes a U-shaped first reinforcing member 3E11 and a second reinforcing member 3E12 made of a nonmagnetic material (for example, plastic) that can be divided into two. The first reinforcing member 3E11 and the second reinforcing member 3E12 are formed in an annular shape by overlapping both ends. The first reinforcing member 3E11 and the second reinforcing member 3E12 are each formed in a U shape along a semicircle.

  The first reinforcing member 3E11 and the second reinforcing member 3E12 are provided in a band plate shape, and are formed in a U shape so that both end portions in the longitudinal direction face each other in the thickness direction. The first reinforcing member 3E11 and the second reinforcing member 3E12 are provided in the same size and the same shape, and through holes through which a first belt-like magnetic body 3E2 and a second belt-like magnetic body 3E3 described later are passed in the center in the longitudinal direction. 3E13 is provided. As shown in FIG. 26, the outer surface of one end T11 of the first reinforcing member 3E11 and the inner surface of the other end T22 of the second reinforcing member 3E12 are opposed to each other, and the other end T12 of the first reinforcing member 3E11. And the outer surface of the one end T21 of the second reinforcing member 3E12 are opposed to each other to form an annular reinforcing body 3E1.

  The first strip-shaped magnetic body 3E2 and the second strip-shaped magnetic body 3E3 divided into two are, for example, in the shape of a thin strip having a thickness of 100 μm or less, and are flexible, as in the first and second embodiments. . As shown in FIG. 26, the first belt-like magnetic body 3E2 passes through the through hole 3E13 of the first reinforcing member 3E11, on the outer surface of one end T11 of the first reinforcing member 3E11, and the other end T12 of the first reinforcing member 3E11. It is wound on the inner surface of or attached to it. The second belt-like magnetic body 3E3 passes through the through hole 3E13 of the second reinforcing member 3E12 and is wound on the outer surface of one end T21 of the second reinforcing member 3E12 and on the inner surface of the other end T22 of the second reinforcing member 3E11. Alternatively, it is provided by pasting.

  The first belt-like magnetic body 3E2 is provided across both end portions T11 and T12 of the first reinforcing member 3E11. The second belt-like magnetic body 3E3 is also provided across the second reinforcing member 3E12 at both ends T21, T22. As a result, as shown in FIG. 27, when both end portions T11, T12, T21, and T22 of the first reinforcing member 3E11 and the first reinforcing member 3B12 are overlapped with each other, the first belt-like magnetic body 3B2 and the second belt-like magnetic body 3B3. Both end portions T11, T12, T21, and T22 are overlapped and contacted in the thickness direction.

  These exciting cores 3E are accommodated in the accommodating case 7 shown in FIGS. As shown in the figure, the housing case 7 is composed of a first case portion 71 and a second case portion 72 which are formed of different parts. Each of the first case portion 71 and the second case portion 72 is formed in a rectangular tube shape, and the tube length direction is formed in a substantially U shape along a circle. The first reinforcing member 3E11 is accommodated and fixed in the first case portion 71, and the second reinforcing member 3E12 is accommodated and fixed in the second case portion 72.

A hinge portion 73 is provided at one end T41 and T51 of the first case portion 71 and the second case portion 72. The hinge part 73 is provided with a shaft part 73A parallel to the central axis of the exciting core 3E. As a result, the first case portion 71 and the second case portion 72 are rotatable about the shaft portion 73A of the hinge portion 73, and the other end portions T42 and T52 are freely contactable / separated around the hinge portion 73. As shown in FIGS. 27 and 28, the shaft portion 73 </ b> A of the hinge portion 73 is in a state where both ends of the first belt-like magnetic body 3 </ b> E <b> 2 and the second belt-like magnetic body 3 </ b> E <b> 3 housed in the housing case 7 are overlapped. is provided in a position shifted from on the line L ₁ passing through the center O ₁ of the opposite ends an annular first strip magnetic 3E2 and the second band-shaped magnetic member 3E3.

In this embodiment, the shaft portion 73A is a on a circle reinforcement 3E1 form, are provided at the other end T22 of the second reinforcing member 3E12 than the position A on the straight line L _1. According to the above configuration, as shown in FIGS. 27 and 28, the first reinforcing member 3E11 and the second reinforcing member 3E12 can be opened and closed with the shaft portion 73A of the hinge portion 73 as a center.

  According to the structure mentioned above, the 1st case part 71 and the 2nd case part 72 are rotated centering on the hinge part 73 so that the other end parts T42 and T52 of the 1st case part 71 and the 2nd case part 72 may be separated. Thereby, as shown in FIG. 28, the first reinforcing member 3E11 and the second reinforcing member 3E12 accommodated in the accommodating case 7 rotate around the shaft portion 73A, and both end portions thereof are separated from each other. Both end portions of the first belt-like magnetic body 3E2 and the second belt-like magnetic body 3E3 provided on the first reinforcing member 3E11 and the second reinforcing member 3E12 are similarly separated from each other and become in an unclamped state. Thereafter, the object 9 to be measured is passed through the gap between the other end portions T12 and T22 of the separated first reinforcing member 3E11 and second reinforcing member 3E12.

  Next, the first case portion 71 and the second case portion 72 are rotated around the hinge portion 73 so that the other end portions T42 and T52 of the first case portion 71 and the second case portion 72 are brought closer to each other. Thereby, as shown in FIG. 27, the first reinforcing member 3E11 and the second reinforcing member 3E12 housed in the housing case 7 rotate around the shaft portion 73A, and both end portions thereof approach each other in the thickness direction. Is superimposed on. Thereby, both ends of the 1st strip | belt-shaped magnetic body 3E2 and 2nd strip | belt-shaped magnetic body 3E3 provided on these 1st reinforcement member 3E11 and 2nd reinforcement member 3E12 are also piled up in thickness direction, and will be in a clamp state.

  As shown in FIG. 30, both end portions of the exciting core 3E protrude from the other end portions T42 and T52 of the first case portion 71 and the second case portion 72, respectively. When the other end portions T42 and T52 of the first case portion 71 and the second case portion 72 are brought close to each other, both end portions of the excitation core 3E are overlapped in the thickness direction, and as shown in FIG. 31, the first case portion 71 and the end surfaces of the other end portions T42 and T52 of the second case portion 72 come into contact with each other.

  According to the third embodiment described above, both end portions of the first strip-shaped magnetic body 3E2 and the second strip-shaped magnetic body 3E3 are overlapped and contacted in the thickness direction. Accordingly, a sufficient contact area can be maintained for the opening / closing operation of the first belt-like magnetic body 3E2 and the second belt-like magnetic body 3E3, and therefore, a thin-band magnetic body can be adopted as the split clamp type excitation core 3E. it can.

  According to the third embodiment described above, the first belt-like magnetic body 3E2 is provided on the first reinforcing member 3E11, and the second belt-like magnetic body 3E3 is provided on the second reinforcing member 3E12. Thereby, even if it is flexible 1st strip | belt-shaped magnetic body 3E2 and 2nd strip | belt-shaped magnetic body 3E3, since a shape can be maintained, mechanical strength is not affected, without affecting the characteristic of the excitation core 3E. Can be planned.

According to the third embodiment described above, similarly to the first embodiment, the first reinforcing member 3E11 and the second reinforcing member 3E12 that support the first belt-like magnetic body 3E2 and the second belt-like magnetic body 3E3 are provided with the shaft portion 73A. It can be opened and closed around the center. The shaft portion 73A is provided on the first band-shaped magnetic member 3E2, it deviates from the straight line L ₁ passing through the center O ₁ of the annular end portions and the exciting core 3E of the second strip-shaped magnetic 3E3 position. Thereby, when clamping, it can reduce that both ends of 1st strip | belt-shaped magnetic body 3E2 and 2nd strip | belt-shaped magnetic body 3E3 rub against each other.

In addition, according to 3rd Embodiment mentioned above, although the axial part 73A was provided on the circle | round | yen which the exciting core 3E forms, it is not restricted to this. The shaft portion 73A, may be provided on a position displaced from the straight line L _1, as shown in FIG. 32, may be provided a shaft portion 73A on the outer side of the circle exciting core 3A is formed.

  In this case, as shown in FIG. 33 to FIG. 35, projecting portions 711 and 712 projecting to the outside of the ring are provided at one end portions T41 and T51 of the first case portion 71 and the second case portion 72. 712 may be provided with a hinge portion 73.

(Fourth embodiment)
Next, a non-contact type current sensor according to a fourth embodiment will be described with reference to the drawings. The difference between the third embodiment and the fourth embodiment is the configuration of the exciting core 3F, and the current detection circuit 10 is the same as that of the first embodiment, and thus detailed description thereof is omitted here.

As shown in FIG. 36, the sensor head 2 includes a reinforcing body 3F1, a first belt-like magnetic body, and a second belt-like magnetic body (omitted from FIG. 36). The difference between the third embodiment and the fourth embodiment is the position of the shaft portion 73A (hinge portion 73). In the third embodiment, the shaft portion 73A, as shown in FIG. 27, is provided at a position displaced from the top straight line L _1. In contrast, in the second embodiment, the shaft portion 73A, as shown in FIG. 36, first, a on a circle the second strip-shaped magnetic body is formed, it is provided on the straight line L _1.

  Further, the first reinforcing member 3E11 and the second reinforcing member 3E12 of the third embodiment and the first reinforcing member 3F11 and the second reinforcing member 3F12 of the fourth embodiment are different from each other in the first reinforcing member 3F11 and the second reinforcing member 3F12. 2 It is the shape of both ends T11, T12, T21, and T22 of the reinforcing member 3F12. In the third embodiment, both end portions T11, T12, T21, and T22 of the first reinforcing member 3F11 and the second reinforcing member 3F12 are provided along a circle, but in the fourth embodiment, the first reinforcing member 3F11 is provided. And both ends T11, T12, T21, and T22 of the second reinforcing member 3F12 are formed so as to deviate from a circle formed by an intermediate portion between both ends as shown in FIG.

  In the present embodiment, the other end T12 of the first reinforcing member 3F11 and the one end T21 of the second reinforcing member 3F12 are bent inward from the circle and are formed along a straight line. Also, one end T11 of the first reinforcing member 3F11 and the other end T22 of the second reinforcing member 3F12 are bent outward from the circle and are formed along a straight line. First and second belt-like magnetic bodies (not shown) are disposed on the first reinforcing member 3F11 and the second reinforcing member 3F12, respectively.

  According to the fourth embodiment described above, both end portions of the first and second reinforcing members 3F11 and 3F12 are formed so as to deviate from the circle formed by the intermediate portion between both end portions, as shown in FIG. Has been. Even if comprised in this way, when the both ends of 1st, 2nd reinforcement member 3F11, 3F12 are clamped close, the 1st, 2nd strip | belt-shaped magnetic body on these 1st, 2nd reinforcement member 3F11, 3F12 It is possible to reduce the rubbing between the two end portions.

Incidentally, according to the fourth embodiment, the shaft portion 73B has been provided on a straight line L _1, not limited to this. Shank 73B, as shown in FIG. 37, similar to the third embodiment, may be a position shifted from on the straight line L _1.

(Modification)
In the first to fourth embodiments described above, the excitation cores 3A to 3F are not provided with the cushion materials (elastic members) 3A31 and 3A41 shown in FIGS. 38 and 39, but the cushion materials 3A31 and 3A41 are provided. It may be. 38 and 39 show an embodiment in which cushion materials 3A31 and 3A41 are provided on the exciting core 3A of the first embodiment. As shown in the drawing, the other end portion T12 of the first reinforcing member 3A11 is from a portion other than the other end portion T12 such that the outer surface is on the inner side of the ring than the outer surface of the portion other than the other end portion T12. Is also provided with a small thickness.

  The other end portion T22 of the second reinforcing member 3A12 is provided with a smaller thickness than the portion other than the other end portion T22 so that the inner surface thereof is on the outer side of the ring shape than the inner surface of the portion other than the other end portion T22. ing. Cushioning materials 3A31 and 3A41 are provided between the other end portions T12 and T22 provided thin and the belt-like magnetic body 3A2 provided on the other end portions T12 and T22, respectively. The cushion material 3A31 is provided on the end portion T12 of the first reinforcing member 3A11 so that the outer surface protrudes outside the circle from the outer surface other than the end portion T12 of the first reinforcing member 3A11. Yes. The cushion material 3A41 is provided on the end portion T22 of the second reinforcing member 3A12 so that the inner surface of the cushion material 3A41 protrudes inside the circle from the inner surface other than the end portion T22 of the first reinforcing member 3A11.

  The cushion materials 3A31 and 3A41 are made of an elastic member such as silicon rubber, urethane, or foam material. When both end portions of the belt-like magnetic body 3A2 are overlapped as shown in FIG. 39, the end portions are biased toward each other. Thereby, the contact of both ends of the strip-shaped magnetic body 3A2 becomes good, and the characteristics can be further improved.

  The configuration in which the cushion materials 3A31 and 3A41 are provided can also be applied to the second to fourth embodiments. In the third and fourth embodiments, when the cushioning material is provided at both end portions T11 and T12 of the first reinforcing members 3E11 and 3F11 and both end portions T11 and T12 of the second reinforcing members 3E12 and 3F12, respectively, Contact between both ends of the magnetic body 3E2 and the second belt-like magnetic body 3E3 can be improved.

  In FIGS. 38 and 39, the cushion members 3A31 and 3A41 are provided on both the other end T12 of the first reinforcing member 3A11 and the other end T22 of the second reinforcing member 3A12. However, the present invention is not limited to this. Absent. As shown in FIGS. 40 and 41, the same effect can be obtained by providing cushion members 3A31 and 3A41 on either one of the other end T12 of the first reinforcing member 3A11 and the other end T22 of the second reinforcing member 3A12. Obtainable. 40 and 41 are diagrams showing an embodiment in which a cushion material 3A41 is provided at the other end T22 of the second reinforcing member 3A12.

  The configuration shown in FIGS. 40 and 41 can also be applied to the second to fourth embodiments. In the third and fourth embodiments, when a cushion material is provided on one of both ends T11 and T12 of the first reinforcing members 3E11 and 3F11 and one of both ends T11 and T12 of the second reinforcing members 3E12 and 3F12, respectively. The contact between both end portions of the first belt-like magnetic body 3E2 and the second belt-like magnetic body 3E3 can be improved.

  In FIGS. 38 to 39, the cushion members 3A31 and 3A41 are provided on the first reinforcing member 3A11 and the second reinforcing member 3A12. However, the present invention is not limited to this. The cushion members 3A31 and 3A41 may be provided so as to be able to urge both end portions of the belt-like magnetic body 3A2 toward each other. For example, the other end portion T11 of the first reinforcing member 3A11 and the second reinforcing member 3A12. It may be provided between the end T12 and the housing case 7.

  The present invention is not limited to the above embodiment. That is, various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Current sensor 2 Sensor head 3A1-3F1 Reinforcement body 3A2, 3B2 Strip | belt-shaped magnetic body 3A41 Cushion material (elastic member)
3A42 Cushion material (elastic member)
3A14, 3B14 Shaft (shaft)
3E11, 3F11 1st reinforcement member 3E12, 3F12 1st reinforcement member 3E2 1st strip | belt-shaped magnetic body 3E3 2nd strip | belt-shaped magnetic body 10 Current detection circuit (current detection means)
73A Shaft (shaft)
O ₁ center L ₁ straight line

Claims (7)

A reinforcing body made of a non-magnetic material and having both ends overlapped in the thickness direction and formed into a circular shape,
A belt-like magnetic body provided on the reinforcing body and formed in a circular shape with both ends overlapped in the thickness direction;
In the sensor head in which both ends of the band-shaped magnetic body can be contacted and separated by making the reinforcing body openable and closable around an axis parallel to the central axis of the circular reinforcing body,
The shaft is provided at a position shifted from a straight line passing through both end portions and the center of the strip-shaped magnetic body in a state where both ends of the strip-shaped magnetic body are overlapped. A first reinforcing member and a second reinforcing member made of a non-magnetic material and having both ends overlapped in the thickness direction and formed in a circular shape;
A first belt-like magnetic body and a second belt-like magnetic body which are provided on the first reinforcement member and the second reinforcement member and are formed in a circular shape by overlapping both end portions in the thickness direction;
By opening and closing the first reinforcing member and the second reinforcing member around an axis parallel to the central axis of the circular first reinforcing member and the second reinforcing member, the first belt-like magnetic body and In the sensor head in which both end portions of the second belt-like magnetic body can be contacted and separated,
The shaft passes through both ends and the centers of the first and second belt-like magnetic bodies in a state where both ends of the first and second belt-like magnetic bodies are overlapped with each other. A sensor head, wherein the sensor head is provided at a position shifted from a straight line. A reinforcing body made of a non-magnetic material and having both ends overlapped in the thickness direction and formed into a circular shape,
A belt-like magnetic body provided on the reinforcing body and formed in a circular shape with both ends overlapped in the thickness direction;
In the sensor head in which both ends of the band-shaped magnetic body can be contacted and separated by making the reinforcing body openable and closable around an axis parallel to the central axis of the circular reinforcing body,
The reinforcing body is characterized in that an intermediate portion between both end portions of the reinforcing body is formed along a circle, and the both end portions are formed so as to deviate from the circle formed by the intermediate portion. The sensor head. A first reinforcing member and a second reinforcing member made of a non-magnetic material and having both ends overlapped in the thickness direction and formed in a circular shape;
A first belt-like magnetic body and a second belt-like magnetic body which are provided on the first reinforcement member and the second reinforcement member and are formed in a circular shape by overlapping both end portions in the thickness direction;
By opening and closing the first reinforcing member and the second reinforcing member around an axis parallel to the central axis of the circular first reinforcing member and the second reinforcing member, the first belt-like magnetic body and In the sensor head in which both end portions of the second belt-shaped magnetic body can be contacted and separated,
In each of the first reinforcing member and the second reinforcing member, an intermediate portion between both end portions of the first reinforcing member and the second reinforcing member is formed along a circle, and the both end portions are formed by the intermediate portion. A sensor head, wherein the sensor head is formed so as to be out of the circle.   4. The sensor head according to claim 1, further comprising an elastic member that urges both ends of the belt-like magnetic body in a direction in which the two end portions approach each other. 5.   5. The sensor head according to claim 2, further comprising an elastic member that urges both end portions of the first belt-shaped magnetic body and the second belt-shaped magnetic body to approach each other. A sensor head according to any one of claims 1 to 6;
Current detection means for detecting a current flowing through the measurement object passed through the sensor head;
A current sensor comprising: