Current detector

Abstract

A current sensor (100) includes: core members (104a, 104b) arranged in a ring by providing gaps (104c) between their opposing end faces at multiple locations, thereby forming a convergence path for the magnetic field generated by the conduction of the detected current; a housing (102) for housing the core members (104a, 104b) arranged in a ring; and a positioning spacer (108) that applies force to the core members (104a, 104b) in the housing (102) in a mutually opposing direction, thereby positioning the core members (104a, 104b) at a predetermined position that maintains the gaps (104c) at a predetermined interval.

Description

TECHNICAL FIELD

[0001] The present application relates to a current detector that concentrates a magnetic field generated due to conduction of a detected current to a core and detects the current. BACKGROUND

[0002] For example, in the past, a current sensor that arranges a magnetic sensor in a gap formed in a ring-shaped core is disclosed in a publication issued by the Japan Patent Office (JP2012-068158A1). In this current sensor, a container-shaped member is sandwiched in the gap of the core housed in a case, and a resin-made molding member is filled into the case in a state in which an open end portion of the container-shaped member is exposed to the outside to enclose the core inside to fix the core to a desired position.

[0003] In particular, in the above-described prior art, the inner space of the container-shaped member sandwiched in the gap of the core becomes a space in which the resin-made molding member is not present, and therefore, it is considered that even if expansion or contraction due to temperature change of the molding member occurs, stress can be prevented from acting on the magnetic sensor.

[0004] However, as shown in the above-described prior art, in a case where the position of the core is fixed by the molding member filled into the case, due to reasons such as unevenness of the filling amount or filling density and unevenness of the resin, the position at which the core is finally fixed after the resin is cured is not constant, and a variation occurs in each product. In addition, if the fixed position of the core is varied, the position of the Hall element inserted into the gap in the gap also becomes unstable, and therefore, even if the same condition of magnetic flux, the detection accuracy of the Hall element greatly varies in each product. SUMMARY

[0005] An object of the present application is to provide a technique of positioning a core. In order to achieve the object, the present application adopts the following solution.

[0006] The present application provides a current detector. The current detector of the present application includes a plurality of core members and a housing. The plurality of core members are arranged in a ring shape by respectively providing gaps between end faces that face each other at a plurality of positions, thereby forming a convergence path of a magnetic field generated due to conduction of a detected current. In addition, the housing arranges the plurality of core members in a ring shape and houses them. In a state where only the core members are arranged as such, although the gaps are formed, the core members are not correctly positioned. That is, the core members have their respective end faces facing each other and form the gaps, but if the positional relationship with each other deviates in the facing direction, the intervals of the end faces from each other are not constant, and the gaps cannot be maintained at a prescribed interval.

[0007] Therefore, the current detection device of the present application is provided with a positioning member. The positioning member exerts a force on the plurality of core members in mutually opposite directions to each other within the housing, thereby positioning the plurality of core members to predetermined positions at which the gap is maintained at a prescribed interval. Thus, the plurality of core members are positioned in a state in which the interval of the gap between the mutually opposite end faces is maintained as prescribed. In particular, the plurality of core members are forced in the opposite direction, and thus, positional deviation can be reliably prevented after positioning, thereby stably and continuously maintaining the predetermined positions.

[0008] Preferably, the current detection device of the present application is provided with a holding member. The holding member holds the gap at a prescribed interval by being sandwiched between the end faces of the plurality of core members in a state in which the force is exerted by the positioning member. Thus, the force of the positioning member does not act on the interval of the gap in a direction in which the interval is narrowed from the prescribed interval, and the interval of the gap can be stably and continuously maintained.

[0009] In addition, a guide portion can be included in the housing. The guide portion guides the plurality of core members by the outer periphery thereof as the plurality of core members are housed, and positions the plurality of core members in a direction intersecting the opposite direction thereof, thereby causing the end faces to face each other along a converging path.

[0010] The above-described positioning member sets the interval of the gap to a prescribed interval by positioning the core members in the opposite direction, but if the opposite end faces of the core members do not stably and correctly face each other, even if the interval of the gap is the prescribed interval, the magnetic flux passing through the gap leaks and becomes unstable, thereby causing deviation in detection accuracy.

[0011] The above-described guide portion positions the plurality of core members housed in the housing in a state in which the respective end faces face each other at positions at which they originally face each other. Thus, the magnetic flux passing through the gap is stable, and deviation in detection accuracy can be further suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0012] Figure 1A and Figure 1B is a perspective view showing an assembled state of a current sensor of an embodiment.

[0013] Figure 2 is an exploded perspective view schematically showing a configuration of a current sensor of an embodiment.

[0014] Figure 3 is an exploded perspective view schematically showing a configuration of a current sensor of an embodiment.

[0015] Figure 4A and Figure 4B is a perspective view showing an internal structure of a housing.

[0016] Figure 5A and Figure 5Bis a perspective view showing the arrangement of the gap- interval member in the case.

[0017] Figure 6A and Figure 6B is a perspective view showing the arrangement of the magnetic core (core member) in the case.

[0018] Figure 7 is a front view showing the arrangement of the magnetic core housed in the case.

[0019] Figure 8A and Figure 8B is a sectional view along the line VIII-VIII in Figure 7 .

[0020] Figure 9A and Figure 9B is a perspective view showing the arrangement of the positioning interval member for the magnetic core in the case.

[0021] Figure 10 is a front view showing the arrangement of the positioning interval member housed in the case.

[0022] Figure 11 is an exploded perspective view showing the state in which the positioning interval member is separated from the case and the core member.

[0023] Figure 12 is a sectional view along the line XII-XII in Figure 10 .

[0024] Figure 13A and Figure 13B is a sectional view along the line XIII-XIII in Figure 10 .

[0025] Figures 14A to 14C is a sectional view along the line XIV-XIV in Figure 10 .

[0026] Figure 15A and Figure 15B is a view explaining the positioning of the core member by the positioning interval member.

[0027] Figure 16A and Figure 16B is a perspective view showing the arrangement of the circuit board in the case.

[0028] Figure 17 is a front view of a current sensor including the circuit board.

[0029] Figure 18 is a view showing the circuit board of the current sensor in a state halfway through assembly during assembly.

[0030] Figure 19A andFigure 19B is a view showing a circuit board of the current sensor in a state halfway through assembly. DETAILED DESCRIPTION

[0031] Hereinafter, an embodiment of the present application will be described with reference to the drawings. In the following embodiment, a magnetic proportional current sensor is cited as one example of a current detector, but the present application is not limited thereto, and can also be a magnetic balance current sensor or a fluxgate current sensor.

[0032] Figure 1A and Figure 1B is a perspective view showing an assembled state of the current sensor 100 of one embodiment. In addition, Figure 2 and Figure 3 is an exploded perspective view schematically showing the configuration of the current sensor 100 of one embodiment. Further, if the current sensor 100 shown in Figure 1A is shown from a different direction (180° opposite side), it becomes the perspective view of Figure 1B . In addition, in Figure 2 and Figure 3 , the viewing direction in the perspective view is reversed.

[0033] [Overall Configuration]

[0034] As shown in Figure 2 and Figure 3 , the current sensor 100 mainly includes a case 102, a magnetic body core 104, a gap-to-gap spacer 106, a positioning spacer 108, and a circuit board 110, and in a state where the magnetic body core 104, the gap-to-gap spacer 106, the positioning spacer 108, and the circuit board 110 are housed in the case 102, it becomes a usage shown in Figure 1A and Figure 1B . Figures 1A to 3 The current sensor 100 is shown in a posture assuming this usage, in which it is assumed that an unillustrated conductor (bus bar or the like) through which a detected current flows is inserted in the lateral direction (horizontal direction). Further, the current sensor 100 can also be used in other postures (for example, a posture in which it is placed horizontally, a posture in which it stands upright, a posture in which it stands upside down, and the like).

[0035] [Case]

[0036] The case 102 is in the shape of a rectangular container with one end open and the other end closed. In addition, the case 102 is formed with a rectangular through-hole 102a in the center thereof, and thus the container shape of the case 102 is annular as a whole. The through-hole 102a penetrates the center of the current sensor 100 in the thickness direction in the assembled state, and the aforementioned conductor not shown in the drawing is inserted in the horizontal (lateral) direction in the through-hole 102a in the standing posture of the current sensor 100 shown in Fig. 1. Therefore, a flange (not shown) for setting the current sensor 100 in the standing posture is integrally formed in the case 102. Further, the internal structure of the case 102 (the plurality of ribs indicated by reference numerals in the drawing) will be described later.

[0037] [Core member, magnetic core]

[0038] The magnetic core 104 is annular as a whole in the shape of a rectangle. The magnetic core 104 is composed of a pair of core members 104a, 104b. The pair of core members 104a, 104b are each in the shape of a "U" in the lateral direction (so-called U-U type), and are arranged in an annular shape with the two top end faces of the "U" facing each other, thereby constituting one magnetic core 104. At this time, a gap 104c is formed between the end faces of the pair of core members 104a, 104b (at two sites). The core members 104a, 104b are made of a soft magnetic material (for example, ferrite, silicon steel, or the like), and a magnetic field generated around the conductor not shown in the drawing when a current to be detected is conducted therein is concentrated to the magnetic core 104. At this time, the magnetic core 104 forms a convergence path of the magnetic field (magnetic circuit, magnetic path, magnetic flux path) in the circumferential direction thereof.

[0039] [Retaining member]

[0040] The gap-to-gap spacer 106 is made of, for example, a thin plate material of resin. The gap-to-gap spacer 106 is respectively sandwiched and arranged between the gaps 104c of the magnetic core 104. The gap-to-gap spacer 106 retains the gaps 104c at a prescribed interval in a state of being sandwiched between the end faces of the pair of core members 104a, 104b. Specifically, the gap-to-gap spacer 106 can retain the interval of the gaps 104c as a prescribed dimension corresponding to the thickness thereof.

[0041] [Positioning member]

[0042] The positioning spacer 108 is ring-shaped (hole-rectangular shape) that fits with the end face opening of the case 102 or the side face of the magnetic core 104. In addition, the positioning spacer 108 is formed with four leg portions 108b and a locking claw 108c at the periphery (four corners) of a plate-shaped portion (not shown) in addition to a pair of openings 108a formed at the plate-shaped portion that is ring-shaped, and is formed with spring portions 108d at the opposite two side edges. These leg portions 108b or the locking claw 108c and the spring portions 108d extend from the plate-shaped portion toward the inside of the case 102, and in the assembled state of the current sensor 100, the leg portions 108b, the locking claw 108c, and the spring portions 108d are disposed between the outer peripheral face of the magnetic core 104 and the inner surface of the case 102. Thus, the positioning spacer 108 is housed in the case 102 in a manner that covers the side face and the outer peripheral face of the magnetic core 104 from the end face opening side of the case 102. In this housed state, the positioning spacer 108 positions the magnetic core 104 at a predetermined position. Further, the positioning by the positioning spacer 108 is described further below.

[0043] [Circuit substrate]

[0044] In addition, the circuit substrate 110 is also shaped to fit with the end face opening of the case 102 or the side face of the magnetic core 104, but is not connected to be ring-shaped, and has mounting surfaces that are "コ" (kana "ko")-shaped that divide the hole-rectangular shape in half. Two Hall elements 112 are mounted as magnetic detection elements through through-holes at one mounting surface, and a connector 114 is mounted through a through-hole at the other mounting surface. In the assembled state of the current sensor 100, the circuit substrate 110 is housed in the case 102 in a manner that sticks to the side face of the positioning spacer 108. In this housed state, the two Hall elements 112 are disposed within the gap 104c of the magnetic core 104 through the openings 108a of the positioning spacer 108. A circuit for detecting a detected current using the magnetic detection signals of the Hall elements 112 is formed in the circuit substrate 110. Thus, various electronic components (chip components, ICs, etc.) not shown are mounted at the respective mounting surfaces of the circuit substrate 110, and various wiring patterns or through-holes are formed at the respective mounting surfaces and the inner layer. Further, the circuit substrate 110 can be formed to be ring-shaped.

[0045] [Internal structure]

[0046] Next, the internal structure of the case 102 is described.

[0047] Figure 4A and Figure 4B are perspective views that show the internal structure of the case 102. In order to facilitate visual confirmation, the case 102 is shown in a state of being cut in half in the direction of the arrow A2. Figure 4A and Figure 4BThe direction of the housing 102 in the perspective view is different. In addition, in the following description, the long dimension direction of the rectangle when viewed from the opening side of one end surface of the housing 102 in the use mode (erect posture of Fig. 1) is set as the long side direction (lateral direction), and the short dimension direction is set as the short side direction (vertical direction).

[0048] As described above, the housing 102 is formed with the through-hole 102a in the center, and the periphery thereof is surrounded by an inner peripheral wall (not shown) in a rectangular shape. Further, the accommodation space is surrounded by an outer peripheral wall (not shown) in a rectangular shape with a space left from the inner peripheral wall, and a plurality of ribs are formed on the inner surface of the outer peripheral wall and the outer surface of the inner peripheral wall (inner side with respect to the housing 102). In addition, the plurality of ribs each extend in a stripe shape from one end side of the housing 102 toward the other end surface.

[0049] Specifically, first, two gap position ribs 102b, 102c in pairs in the short side direction are formed at the central positions when viewed in the long side direction, respectively. Of these, two gap position ribs 102b are formed on each inner surface of the outer peripheral wall in the short side direction, and two gap position ribs 102c are formed on each outer surface of the inner peripheral wall. In addition, a groove (not shown) is formed between the gap position ribs 102c on each outer surface of the inner peripheral wall.

[0050] Next, a pair of intermediate ribs 102e in the short side direction are formed on the inner surface of the outer peripheral wall at positions where a certain degree of space is left from the gap position ribs 102b in the long side direction, respectively. In addition, a pair of guide ribs 102d in the short side direction are formed at positions where a certain degree of space is left from both sides of the intermediate ribs 102e in the long side direction, and a pair of guide ribs 102d in the short side direction are further formed at positions where a certain degree of space is left from both sides thereof. In addition, the intermediate ribs 102e and the guide ribs 102d are formed only on the inner surface of the outer peripheral wall.

[0051] The above describes the ribs formed on the inner surface extending in the long side direction, but the inner surface extending in the short side direction is also formed with ribs. Specifically, two pairs of auxiliary ribs 102f are formed on each inner surface of the outer peripheral wall in the long side direction. These auxiliary ribs 102f are symmetrically arranged with a space left from the central position in the short side direction.

[0052] In addition to the ribs formed on the inner surface of the housing 102, several ribs are formed, but the description of the content particularly irrelevant to the function of the present embodiment is omitted.

[0053] Next, the arrangement of various constituent parts in the housing 102 is described.

[0054] [Arrangement of Gap-to-Gap Spacers]

[0055] Figure 5A and Figure 5B are perspective views showing the arrangement of the gap- between spacer 106 in the case 102. Also here, in order to facilitate visual confirmation, the direction of viewing the case 102 and the like in the perspective view is made different (the same is true hereafter as well). Figure 5A and Figure 5B are perspective views showing the arrangement of the gap- between spacer 106 in the case 102. Also here, in order to facilitate visual confirmation, the direction of viewing the case 102 and the like in the perspective view is made different (the same is true hereafter as well).

[0056] The gap-between spacer 106 is arranged in a state inserted between the gap- position ribs 102b, 102c, each of which has two, in positions corresponding to the positions of the gap 104c of the magnetic core 104. Further, with respect to the gap-position rib 102c on the inner peripheral wall side, one edge portion of the gap-between spacer 106 is inserted in the groove formed therebetween as described above.

[0057] [Arrangement of magnetic core]

[0058] Figure 6A and Figure 6B are perspective views showing the arrangement of the magnetic core 104 (core members 104a, 104b) in the case 102.

[0059] The magnetic core 104 is arranged in the case 102 in a state sandwiching the gap-between spacer 106 between the two core members 104a, 104b in a state in which the end faces face each other. At this time, the core members 104a, 104b are in a state housed in the case 102 in a state in which the outer peripheral surfaces are supported (or guided) by the above-described plurality of ribs (gap-position ribs 102b, guide ribs 102d, intermediate ribs 102e, auxiliary ribs 102f, and the like). Further, with respect to the inner peripheral surfaces of the core members 104a, 104b, the outer surfaces of the inner peripheral walls of the case 102 support (or guide) them.

[0060] Here, as already described, the magnetic core 104 is an element that greatly influences the detection accuracy (characteristics, performance) of the current sensor 100. The characteristics (magnetic permeability, hysteresis, and the like) of the material of the magnetic core 104 are self-evident, and in the actual arrangement state, it is extremely important that the gap 104c is correctly set at a predetermined interval and the end faces of the core members 104a, 104b facing each other across the gap 104c are arranged in a state in which they face each other directly.

[0061] With respect to this point, although it is possible to carefully check and manage the interval of the gap 104c or the positional relationship of the end faces to each other one by one by human visual inspection and the like during mass production, it is not realistic to provide such a process in terms of working hours or manufacturing costs. Thus, in reality, the quality is managed on the basis of a certain degree of deviation, although it is preferable to suppress the deviation to a minimum.

[0062] Therefore, in the present embodiment, various components are provided with positioning functions, so that the interval of the gap 104c or the positional relationship of the end faces to each other is correctly set. Hereinafter, the positioning of the core members 104a, 104b will be described.

[0063] Figure 7 is a front view showing the arrangement of the magnetic core 104 housed in the case 102. Further, the end face opening of the case 102 is set as the front face (hereinafter, the same applies).

[0064] In this state, the gap 104c is formed between the end faces of the core members 104a, 104b (at two sites), but although the gap interval spacer 106 is sandwiched in the gap 104c, the gap interval DG cannot be ensured to be a prescribed dimension. That is, the reason is that, between the outer surface of each core member 104a, 104b and the inner surface of the case 102 or the rib, there is a margin (gap) of a certain degree of positional deviation of each core member 104a, 104b in both the long side direction and the short side direction.

[0065] [Short side direction positioning]

[0066] On the other hand, in the state shown in Figure 7 , the two core members 104a, 104b have been positioned in a state in which the end faces at the two sites are correctly opposed to each other. This positioning is performed by positioning the core members 104a, 104b in the short side direction, and this positioning is achieved by the guide rib 102d.

[0067] [Guide portion]

[0068] Figure 8A and Figure 8B is a cross-sectional view of the case 102 and the magnetic core 104 along the VIII-VIII line in Figure 7 Figure 8A shows the entire cross section, Figure 8B a portion thereof (enclosed portion by single-dot chain line) is enlarged and shown.

[0069] The guide rib 102d is formed as described above so as to extend in a stripe shape on the inner surface of the outer peripheral wall of the case 102, but at the corner between the inner surface of the outer peripheral wall of the case 102 and the other end face, an inclined guide surface 102g that is tapered between the inner surface of the outer peripheral wall and the other end face is integrally formed. This inclined guide surface 102g is located at a position that guides (or supports) the outer peripheral edge of each core member 104a, 104b in the housed state of the core members 104a, 104b.

[0070] ​At this time, the core members 104a, 104b are positioned in the short side direction within the case 102 by the guidance of the inclined guide surface 102g. Thus, the two core members 104a, 104b can correctly face each other with the end faces opposite to each other. When the two core members 104a, 104b are viewed from between the end faces, the end faces are in a state of facing each other along the magnetic flux path formed in the magnetic core 104.

[0071] [Positioning in long side direction]

[0072] Next, the positioning in the long side direction will be described. The positioning in the long side direction is achieved by the positioning spacer 108 described above.

[0073] Figure 9A and Figure 9B is a perspective view showing the arrangement of the positioning spacer 108 within the case 102 with respect to the magnetic core 104.

[0074] As described above, the positioning spacer 108 is housed within the case 102 in a manner of covering from the side surface side of the core members 104a, 104b. In this state, the positioning spacer 108 prevents the core members 104a, 104b from falling out of the case 102, and forms the positioning in the long side direction. In addition, the openings 108a of the two portions of the positioning spacer 108 are located at positions passing through the respective gaps 104c.

[0075] Figure 10 is a front view showing the arrangement of the positioning spacer 108 housed within the case 102. In addition, Figure 11 is an exploded perspective view showing a state in which the positioning spacer 108 is separated from the case 102 and the core members 104a, 104b.

[0076] As described above, the positioning spacer 108 has the leg portions 108b, the locking claws 108c, and the spring portions 108d. Among them, the leg portions 108b are in a thin plate shape as a whole, and the thickness or width is substantially constant in the insertion direction. The locking claws 108c are in a boss shape in which a "turnback" is formed at the tip end portion. The spring portions 108d are in a pair of plate spring shapes (clip shapes) in the long side direction, and these pair of spring portions 108d can sandwich the two core members 104a, 104b and apply a force to the core members 104a, 104b in the opposite direction.

[0077] In the assembly process of the current sensor 100, these leg portions 108b, locking claws 108c, and spring portions 108d are inserted between the outer peripheral surfaces of the core members 104a, 104b and the inner surfaces of the case 102 after the core members 104a, 104b are housed. In this insertion process, the leg portions 108b, locking claws 108c, and spring portions 108d are sequentially inserted with a time difference, and thus the respective functions are achieved.

[0078] The insertion process is described below.

[0079] [Insertion of the legs]

[0080] Figure 12 is a cross-sectional view of the housing 102 and the positioning spacer 108 (leg 108b) along the XII-XII line in Figure 10

[0081] In the insertion process of the positioning spacer 108, the tip portion of the leg 108b is first inserted along the inner surface of the housing 102, and guides the insertion of the positioning spacer 108 at the four corners. Thus, the insertion start position of the positioning spacer 108 with respect to the end face opening of the housing 102 can be easily obtained during the assembly of the current sensor 100. Further, at the stage where the tip portion of the leg 108b is inserted at the initial stage of the insertion, the other locking claws 108c and the spring portion 108d do not come into contact with the housing 102 or the core members 104a, 104b. In addition, the leg 108b, although in contact with the inner surface of the housing 102, does not come into contact with the core members 104a, 104b even after the insertion is completed.

[0082] [Insertion of the locking claws]

[0083] Figure 13A and Figure 13B is a cross-sectional view of the housing 102, the magnetic core 104, and the positioning spacer 108 (locking claw 108c) along the XIII-XIII line in Figure 10 Figure 13A shows the state at the initial stage of the insertion, Figure 13B shows the state at the completion of the insertion.

[0084] Figure 13A : At the initial stage of the insertion, the locking claw 108c is inserted after the leg 108b, but at this stage the locking claw 108c does not particularly function. Further, the locking claw 108c also does not come into contact with the core members 104a, 104b.

[0085] Figure 13B : On the inner surface of the housing 102, a projection-shaped locking portion 102h is formed corresponding to the position where the locking claw 108c is disposed, and the locking claw 108c functions together with the locking portion 102h at the final stage of the insertion process. That is, at the final stage of the insertion process, the tip portion (folded-back portion) of the locking claw 108c comes into contact with the locking portion 102h and is flexed (elastically deformed) toward the core members 104a, 104b. At this time, the insertion start position of the positioning spacer 108 is determined at the initial stage of the insertion process, and thus the management of the bending load and the amount of flexure to which the locking claw 108c is subjected can be stabilized.

[0086] ​​After that, if the tip portion (folded-back portion) of the locking claw 108c passes the locking portion 102h with the insertion, the locking claw 108c recovers from the flexed state, and the tip portion (folded-back portion) is caught in the locking portion 102h. Thus, the positioning spacer 108 is prevented from falling out of the case 102, and the holding of the core members 104a, 104b is performed.

[0087] [Insertion of spring portion]

[0088] Figures 14A to 14C is a cross-sectional view of the case 102, the magnetic core 104, and the positioning spacer 108 (spring portion 108d) along the XIV-XIV line in Figure 10 . Here, the insertion process is performed in the order of Figure 14A → Figure 14B → Figure 14C .

[0089] Figure 14A : The spring portion 108d extends in a manner that is inclined from the base end toward the central direction, but the tip portion is warped in a direction opposite to the facing direction of the core members 104a, 104b. When viewed from the long-side direction, the warped portion enters the overlapping RP by an amount inward of the outer periphery of the core members 104a, 104b. Thus, during the insertion process, the warped portion of the spring portion 108d is in a positional relationship in which it is in contact with the outer periphery of the core members 104a, 104b.

[0090] Figure 14B : If the insertion continues, the spring portion 108d is in contact with the outer periphery of the core members 104a, 104b at the warped portion. Also in this case, the insertion start position of the positioning spacer 108 is determined at the initial stage of the insertion process, and thus stable management of the bending load and the flexing amount to which the spring portion 108d is subjected can be performed.

[0091] After that, the insertion is further performed, and thus the spring portion 108d is pressed by the outer periphery of the core members 104a, 104b and is flexed as a whole (elastic deformation occurs). At this time, when viewed in both the long-side directions, the spring portion 108d is bent and deformed in a manner that expands outward.

[0092] Figure 14C : In a state in which the insertion is completed, when viewed from the original natural state (indicated by a two-dot chain line), the spring portion 108d is in a state (indicated by a solid line) in which the bending deformation toward the outside of the long-side direction is maintained. At this time, the spring portion 108d exerts a force on the core members 104a, 104b in the facing direction of each other by the restoring force thereof, and the core members 104a, 104b are positioned by the force F from the spring portion 108d. Further, in a state in which the insertion of the positioning spacer 108 is completed, the spring portion 108d is accommodated between the auxiliary ribs 102d.

[0093] [Positioning in the long direction]

[0094] Figure 15A and Figure 15B is a view that explains the positioning of the core members 104a, 104b by the positioning spacer 108. Further, Fig. 15 corresponds to a view in which the cross section shown in Fig. 14 is extended in the long direction. Figures 14A to 14C

[0095] Figure 15A In the present embodiment, the entire width W2 of the magnetic core 104 is set to be longer than the interval Wl of the pair of spring portions 108d of the positioning spacer 108 from each other.

[0096] Here, the interval Wl of the spring portions 108d from each other is the shortest distance between the warped portions of the spring portions 108d as described above. Further, the entire width W2 of the magnetic core 104 is a length obtained by setting the long direction dimension LC of each core member 104a, 104b to a length twice as long as the normal interval DG of the gap 104c. Further, the interval Wl and the entire width W2 can also have a certain degree of tolerance.

[0097] Figure 15B In the state in which the positioning spacer 108 is arranged, the force F from the spring portions 108d acts as described above, and the pair of core members 104a, 104b are forced in the direction opposite to each other and are positioned. At this time, the core members 104a, 104b sandwich the gap interval spacer 106 between the opposing end faces, and are reliably positioned at the central position in the long direction. Thus, the gap 104c can be correctly set to the prescribed interval DG.

[0098] [Arrangement of the circuit board]

[0099] Figure 16A and Figure 16B is a perspective view that shows the arrangement of the circuit board 110 in the case 102.

[0100] As described above, the circuit board 110 has an outer shape in which the mounting surface is in a "コ" shape, and is arranged in the case 102 in a manner that it is stuck to the outer surface of the positioning spacer 108 in the assembled state of the current sensor 100. Further, as for the Hall element 112 (not shown in Figure 16A and Figure 16B , Figure 17 , the magnetic sensing portion (magnetic sensing surface) is arranged in the gap 104c through the opening 108a of the positioning spacer 108.

[0101] ​Here, in order to cause the Hall element 112 to properly perform a detection operation in the current sensor 100, it is necessary to properly position the configuration of the Hall element 112 (magnetic sensing portion) within the gap 104c. Since the Hall element 112 is mounted to the circuit board 110, the position of the Hall element 112 with respect to the circuit board 110 can be considered constant. Therefore, in the present embodiment, the circuit board 110 is properly positioned with respect to the case 102, thereby properly positioning the position of the Hall element 112 (magnetic sensing portion) within the gap 104c.

[0102] [Positioning of Circuit Board]

[0103] Figure 17 is a front view of the current sensor 100 including the circuit board 110. The positioning of the circuit board 110 uses the gap position ribs 102b and the auxiliary rib 102f of the case 102. Therefore, in the circuit board 110, in addition to the cutout portions 110a formed at two portions of the outer edge portion, a cutout portion 110c is formed at one portion, the positions of the respective cutout portions 110a correspond to the positions of the gap position ribs 102b in the configuration state of the circuit board 110, and the position of the cutout portion 110c corresponds to the position of the auxiliary rib 102f. Further, in addition thereto, the cutout portion 110b is formed at the outer edge portion of the circuit board 110.

[0104] Specifically, the gap position ribs 102b are each arranged in two rows in the longitudinal direction in correspondence with the respective gaps 104c. The cutout portion 110a corresponding thereto has a size capable of accommodating the entire arrangement of the two rows of gap position ribs 102b. In addition, the auxiliary rib 102f is provided in two pairs of two sides in the longitudinal direction, but the auxiliary rib 102f corresponding to the cutout portion 110c is one portion thereof. In addition, the cutout portion 110c also has a size capable of accommodating the corresponding one auxiliary rib 102f. Therefore, in the state in which the circuit board 110 is housed in the case 102, the two portions of the cutout portion 110a become a state in which the entire arrangement of the gap position ribs 102b is respectively accommodated, and the one portion of the cutout portion 110c becomes a state in which the one auxiliary rib 102f is accommodated, whereby the circuit board 110 is properly positioned (at a predetermined position). Thereby, it is possible to position the Hall element 112 to a proper position (positioning unit) within the gap 104c without interference with the core members 104a, 104b or the gap-to-gap spacers 106, and the like. Further, it is also possible to omit the auxiliary rib 102f and the cutout portion 110c.

[0105] [Configuration Freedom]

[0106] The circuit board 110 can be changed to be Figure 17The first configuration shown is different from a second configuration. Specifically, if the circuit board 110 is rotated 180° in the circumferential direction of the through-hole 102a from the first configuration, the second configuration is obtained (not shown). In the first configuration, the connector 114 is located in the lower right corner when viewed from the front, but in the second configuration, the connector 114 is located in the upper left corner. Thus, the position at which the connector 114 is connected (winding of the wire) can be selected in correspondence with the actual use environment of the current sensor 100. Figure 17

[0107] In addition, in the second configuration as well, in the state in which the entire arrangement of the gap position ribs 102b is housed in the cutout portions 110a at two locations as described above, the circuit board 110 can be normally positioned.

[0108] As described above, in the state in which the circuit board 110 is housed in the case 102 (assembled state), the circuit board 110 is normally positioned, and thus both of the Hall elements 112 are appropriately disposed in the corresponding gaps 104c. However, in the assembly process of the current sensor 100 (stage before assembly), since the circuit board 110 is not positioned, it is not possible to ensure, for example, that the two Hall elements 112 are aligned with the corresponding gaps 104c midway through the operation of housing the circuit board 110 in the case 102.

[0109] Thus, in the assembly process of the current sensor 100, if the circuit board 110 is assembled in a state in which the position is not yet determined, the Hall element 112 that protrudes greatly from the mounting surface can come into contact with a portion other than the gap 104c (the outer surface of the positioning spacer 108 or the outer surface of the core members 104a, 104b, etc.), and can be damaged (deformation such as bending of each lead terminal, breakage of the element itself, etc.).

[0110] Of course, in the assembly operation, for the purpose of caution, it can be said that the position of the Hall element 112, etc. can be carefully adjusted one by one by visual inspection by a person before the circuit board 110 is assembled in the mass production process, but it is not realistic in terms of working hours or manufacturing costs to provide such a process.

[0111] Therefore, in the present embodiment, a structure is provided in which the assembly (housing in the predetermined position) of the circuit board 110 is permitted only in a case in which the circuit board 110 is aligned with the opening of one end surface of the case 102 in the normal assembly position. Hereinafter, this point will be described.

[0112] [Restriction of Housing (1)]

[0113] Figure 18 is a view showing the circuit board 110 in the current sensor 100 in a state midway through assembly (along the direction of the arrow A in FIG. 1). Figure 17 ​(Cross view of line XVIII-XVIII).

[0114] Before being housed in the housing 102, i.e., during assembly, the circuit board 110 is not yet in its normal position, and it cannot be guaranteed that it will be directly aligned with the normal assembly position. In the illustrated example, the circuit board 110 is offset from its original assembly position in the direction of arrow A1 (short side direction) in the figure. Therefore, the center of the Hall element 112 is offset further in the direction of arrow A1 than the center of the opening 108a.

[0115] In this embodiment, for example, Figure 18 As shown, even when the circuit board 110 is not aligned with its normal mounting position, if the circuit board 110 is to be housed in the housing 102, the circuit board 110 (mounting surface) will contact the edge of the opening at one end of the housing 102, thus hindering its placement. Moreover, even if the circuit board 110 contacts the edge of the opening of the housing 102, since the depth DP from the edge of the opening of the housing 102 to the outer surface of the positioning spacer 108 is set to be greater than the mounting height HT of the Hall element 112, the Hall element 112 will not interfere with other components.

[0116] [When storage is permitted (1)]

[0117] Furthermore, although not shown in the figure, if the circuit board 110 is removed from... Figure 18 If the circuit board 110 is correctly housed in the housing 102 as shown, an operator or machine operator needs to modify the circuit board 110 to be aligned with its normal assembly position. Moreover, the circuit board 110 may be housed in the housing 102 only if the Hall element 112 travels a path that does not interfere with the outer surfaces of the positioning spacers 108 or the core components 104a, 104b.

[0118] [Storage Restriction Methods (2)]

[0119] Figure 19A and Figure 19B It will be from and Figure 18 The circuit board 110 during the assembly of the current sensor 100 in different orientations is shown in a diagram at the mid-assembly stage (along...). Figure 17 (Cross view of line XIX-XIX).

[0120] [When storage is limited]

[0121] Figure 19AFor example, the circuit board 110 does not face the normal mounting position, even if the circuit board 110 is to be housed in the housing 102 in a state of being positionally deviated in the long side direction of the housing 102 (the direction of the arrow A2 in the drawing), the circuit board 110 (mounting surface) will come into contact with the edge of the opening of the housing 102 at one end and hinder the housing. Also, even if the circuit board 110 comes into contact with the edge of the opening of the housing 102, since the depth DP from the edge of the opening of the housing 102 to the outer surface of the positioning spacer 108 is set to be larger than the mounting height HT of the Hall element 112, the Hall element 112 will not interfere with other constituent members.

[0122] [When housing is permitted (2)]

[0123] Figure 19B Thereafter, if the operator or the work machine makes the circuit board 110 face the normal mounting position, the circuit board 110 is permitted to be housed in the housing 102 only in a case where a normal path toward the mounting position is passed from this state. The housing (mounting work) of the circuit board 110 is permitted only in a case where such a normal path is passed, and thus it is possible to reliably prevent the Hall element 112 from being damaged by interference with the outer surface of the positioning spacer 108 or the core members 104a, 104b.

[0124] Further, the above example is about a case where the circuit board 110 is deviated in an arbitrary one direction (the arrows Al, A2), but a case where the circuit board 110 is deviated in both directions in combination is also similarly restricted from being housed in the housing 102 from this state.

[0125] In any case in the present embodiment, the circuit board 110 is permitted to be housed in the housing 102 only in a case where a normal path in which the Hall element 112 does not interfere with other constituent members is passed during assembly of the current sensor 100. Thus, it is possible to ensure the quality of the completed current sensor 100 without the Hall element 112 being damaged during assembly.

[0126] The current sensor 100 according to the above embodiment can achieve the following advantages.

[0127] (1) In a case where the magnetic core 104 is constituted by a plurality of core members 104a, 104b, although it is difficult to make the gap 104c close to a required value in terms of structure due to a deviation in the positional accuracy of each core member 104a, 104b, in the present embodiment, the two core members 104a, 104b are forced in the direction of facing each other and positioned by the spring portion 108d of the positioning spacer 108, and thus it is possible to maintain the state in which the gap interval is made close to the required value by the gap interval spacer 106 that is sandwiched between the end surfaces.

[0128] (2) The force application and positioning by the positioning spacer 108 after the product is shipped also effectively functions, so even if there is an influence of the use environment of the current sensor 100 (for example, temperature change, etc.), the force from the spring portion 108d acts in a direction to maintain the gap interval to the required value, so it is possible to maintain the detection accuracy for a long period of time.

[0129] (3) The positioning spacer 108 is assembled in a manner of being covered from the outside of the case 102 after the core members 104a, 104b are assembled, so the workability is high, and it is possible to correctly position the core members 104a, 104b by a simple and easy work.

[0130] (4) The positioning spacer 108 has a function of positioning itself to an insertion start position which is open to one end surface of the case 102 (leg portion 108b), so it is possible to stabilize the manner (position or angle) in which the engagement claw 108c or the spring portion 108d comes into contact with the engagement portion 102h or the core members 104a, 104b at the time of assembly. Due to this, it is possible to easily manage the load and the amount of deflection which the engagement claw 108c or the spring portion 108d receives, and it is possible to reliably prevent breakage and the like at the time of assembly work.

[0131] (5) In addition, by merely housing the core members 104a, 104b in the case 102, the guide ribs 102d align the core members 104a, 104b themselves to the central position in the short side direction, so the worker or the work machine does not need to consider positioning one by one, and the workability is further improved.

[0132] (6) When the assembly work of the circuit board 110 (housing in the case 102) is performed, it is possible to restrict assembly from an abnormal and inappropriate path, so the worker or the work machine does not mistakenly damage the electronic components such as the Hall element 112.

[0133] (7) Conversely, even if the worker or the like touches the normal path which allows assembly of the circuit board 110 to perform trial and error, if assembly of the circuit board 110 is allowed, since it is a normal assembly path, the work can be easily and reliably completed even without special attention.

[0134] (8) Due to this, it is possible to improve the production efficiency of the current sensor 100 and achieve cost reduction.

[0135] The present application is not limited to the above-described embodiment, and various modifications can be made and implemented. For example, the overall shape of the current sensor 100 can also be a shape other than a rectangular ring shape. Also, it can be a configuration in which the housing 102 is filled with sealing resin or the like in a state in which the magnetic core 104 or the gap interval member 106, the positioning interval member 108, the circuit board 110, and the like are housed in the housing space. In this case as well, the positioning using the force of the positioning interval member 108 effectively functions, and thus it is possible to compensate for the effects of volume changes of the filling resin or the like and to maintain the interval of the gap 104c over a long period of time.

[0136] The housing 102 can also be configured in a manner in which it is divided into multiple portions, and can have an openable and closable cover. Also, the shape of the housing 102 or the arrangement of the ribs (the gap position ribs 102b, 102c, the guide rib 102d, the intermediate rib 102e, the auxiliary rib 102d, and the like) can be appropriately modified in cooperation with the shape of the core members 104a, 104b used, and the number thereof is not limited to the examples listed in the embodiments.

[0137] The magnetic core 104 has the gap 104c at the central position in the long direction, but can have the gap 104c at another position. Also, the number of gaps 104c can be more than two. In this case as well, the positioning interval member 108 not only exerts a force in the opposing direction but also performs positioning, and thus it is possible to appropriately maintain the interval of each gap 104c.

[0138] In the embodiments, as one example of the magnetic core 104, a two-piece core member 104a, 104b is listed, but a magnetic core in which multiple plate-shaped core members are stacked can also be used. In this case, the positioning using the spring portion of the positioning interval member can be configured to exert a force in the stacking direction of the plate-shaped core members in a state in which they are stacked and to perform positioning.

[0139] The positioning of the circuit board 110 can also be performed using a configuration other than the fitting of the gap position rib 102b and the cutout portion 110a. For example, a positioning-specific rib can be formed separately on the housing 102, and a cutout portion corresponding thereto can be formed on the circuit board 110. Also, a configuration in which a convex portion is protrusively formed on the outer edge of the circuit board 110, and a recess portion capable of housing the convex portion is formed on the housing 102 and is configured as a positioning unit can also be used. Also, the number of portions to be positioned can be three or more.

[0140] Furthermore, the configuration listed together with the drawings in the embodiments and the like is only one example that is preferable, and the present application can of course be appropriately implemented even if various elements are added to the basic configuration or a portion is replaced.

Claims

1. A current detector comprising: a plurality of core members that form a convergence path of a magnetic field generated by conduction of a detected current by being arranged in a ring shape with gaps respectively provided between end faces that oppose each other at a plurality of sites; and a housing that houses the plurality of core members arranged in a ring shape, characterized in that the current detector further comprises a positioning member that is positioned by the housing at an initial stage of insertion of the positioning member into the housing and is not in contact with the core members, comes into contact with the plurality of core members by further insertion of the positioning member into the housing, and exerts a force on the plurality of core members in a direction opposite to that of elastic deformation of a site elastically deformed by the contact, thereby positioning the plurality of core members at predetermined positions that maintain the gaps at a prescribed interval.

2. The current detector according to claim 1, characterized in that the current detector further comprises a holding member that holds the gaps at the prescribed interval by being sandwiched between the end faces of the plurality of core members in a state of being subjected to the force of the positioning member.

3. The current detector according to claim 1 or 2, characterized in that the housing has a guide portion that guides the plurality of core members by a peripheral edge with the housing and positions the plurality of core members in a direction intersecting the direction of opposition, thereby making the end faces face each other along the convergence path.

4. The current detector according to claim 1 or 2, characterized in that the positioning member positions the core members in a state of being housed together with the plurality of core members in the housing.

5. The current detector according to claim 3, characterized in that the positioning member positions the core members in a state of being housed together with the plurality of core members in the housing.

6. The current detector according to claim 1 or 2, characterized in that the current detector further comprises a circuit board that is housed together with the plurality of core members in the housing and is formed with a circuit that detects a detected current using an output signal from a magnetic detection element arranged in the gap, the positioning member positions the plurality of core members at a position at which the magnetic detection element mounted on the circuit board is arranged at a fixed position in the gap as the predetermined position.

7. The current detector according to claim 3, characterized in that the current detector further comprises a circuit board that is housed together with the plurality of core members in the housing and is formed with a circuit that detects a detected current using an output signal from a magnetic detection element arranged in the gap, the positioning member positions the plurality of core members at a position at which the magnetic detection element mounted on the circuit board is arranged at a fixed position in the gap as the predetermined position.

8. The current detector according to claim 4, characterized in that ​ ​ ​ ​ ​ ​ ​ ​ ​ The current detector further includes a circuit board that is housed in the housing together with the plurality of core members and that is provided with a circuit for detecting a detected current using an output signal from a magnetic detection element disposed in the gap, The positioning member positions the plurality of core members with a position at which the magnetic detection element mounted to the circuit board is disposed at a fixed position in the gap as the predetermined position.

9. The current detector according to claim 5, wherein The current detector further includes a circuit board that is housed in the housing together with the plurality of core members and that is provided with a circuit for detecting a detected current using an output signal from a magnetic detection element disposed in the gap, The positioning member positions the plurality of core members with a position at which the magnetic detection element mounted to the circuit board is disposed at a fixed position in the gap as the predetermined position.

Images