WO2023167249A1

WO2023167249A1 - Current detector

Info

Publication number: WO2023167249A1
Application number: PCT/JP2023/007650
Authority: WO
Inventors: 誠橋本; 悠介大野
Original assignee: 株式会社タムラ製作所
Priority date: 2022-03-04
Filing date: 2023-03-01
Publication date: 2023-09-07
Also published as: JP2023128994A

Abstract

Provided is a core positioning technology.　A current sensor 100 comprises: a pair of core members 104 that are positioned assembled together in a ring shape around a primary conductor, in a condition in which respective end surfaces 104a of both end sections of each have been made to face each other; a case body 102 that has an insertion section 103 through which the primary conductor can be inserted, and accommodates the pair of core members 104 in the interior thereof via an opening that is formed in a ring shape around the insertion section 103; spring spacers 108 that produce a force pressing the pair of core members 104 together in the facing direction from outside surfaces thereof, which are on the opposite sides from the respective end surfaces 104a; gap spacers 106 that are respectively positioned in locations where the respective end surfaces 104a of the pair of core members 104 are facing, receive the respective end sections of the core members into pairs of recessed sections 106a, and in this condition form gaps between the end surfaces 104a and suppress displacement of the core members 104; and a circuit board 110.

Description

current detector

The present invention relates to a current detector that detects current to be detected.

For example, conventionally, there is known a prior art of a current detection device in which an apron-shaped mounting portion is provided in a gap portion formed in an annular core (see Patent Document 1, for example). In this current detection device, the mounting portion of the resin member is insert-molded in advance so as to straddle the gap portion of the core, and when the core is fixed to the case, the integrally molded mounting portion is screwed to the case. , the printed circuit board on which the magnetoelectric conversion element is mounted is also fastened together with the mounting portion.

In particular, in the above prior art, by embedding the gap portion of the core in an insert-molded resin member, it is possible to suppress changes in the gap between the cap portions due to expansion and contraction caused by temperature changes. Further, it is considered that the positions of the gap portion and the magnetoelectric conversion element can be accurately set by fastening the mounting portion to the case and the printed circuit board together.

Japanese Utility Model Laid-Open No. 6-86080

However, in the case where the gap is formed in the single ring-shaped core as in the prior art, even if the resin member is insert-molded, the change in the gap distance due to the thermal deformation of the core itself cannot be avoided. can't Further, insert molding the resin member in advance leads to an increase in the number of man-hours.

On the other hand, if a plurality of divided core members are simply combined into a ring and arranged in a case, although a gap is formed between the core members, the core members are positioned correctly and the posture is maintained. Otherwise, there is a problem that the gap interval and the gap position itself are not stable.

Therefore, the present invention provides a core positioning technology.

The present invention provides the following solutions. Note that parentheses and the like in the following description are merely examples, and the present invention is not limited to them.

A current detector of the present invention includes a pair of core members and a case body. Each of the pair of core members has a partial annular shape, and is arranged in a ring around the primary conductor through which the current to be detected flows, with the end faces of both ends facing each other. With this arrangement, the pair of core members form a convergence path of the magnetic field generated by conduction of the current to be detected. Further, the case body has an insertion portion (insertion hole, through hole, penetration portion, etc.) through which the primary conductor can be inserted. is a container-like member that can accommodate However, the distance and the position of the gap cannot be determined only by accommodating a pair of core members in the case body and arranging them in an annular shape.

Therefore, the current detector of the present invention further includes a pressing member and a gap spacer. First, the pressing member generates a force that presses the pair of core members in opposite directions from the outer side surfaces opposite to the end surfaces of the pair of core members while being accommodated in the case body. One pressing member may be provided for each core member, or one pressing member may be provided for both of a pair of core members. In this manner, the pressing member generates a force that presses the pair of core members in the facing direction in the case body, thereby preventing the end faces from separating from each other.

Next, the gap spacer forms a gap of a specified interval between the facing end faces of the pair of core members, and is therefore accommodated in the case together with the pair of core members. That is, the gap spacers are arranged at locations (two locations) where the end surfaces of the pair of core members face each other, and the pair of core members facing each other are provided in a pair of concave portions formed with the opening surfaces facing back to each other. A defined gap is formed between the end faces while receiving the ends of the . In this way, while the pair of core members are pressed in the opposing direction by the pressing member, the end portions of the pair of core members are pushed (against the pressing force) in the concave portions of the gap spacers at the locations where the respective end faces face each other. ) are received and positioned with a gap distance maintained between the end faces. The current detector has a circuit board, and the circuit board detects the current to be detected using a magnetic detection element (Hall sensor, probe coil, etc.) placed in the gap while being housed in the case body. A detection circuit is formed to

The inventors of the present invention conceived that it is effective for stably maintaining the gap distance to receive each end portion with a gap spacer (recess) while pressing the pair of core members in the opposing direction as described above. However, we have obtained unique knowledge that suppressing the displacement of the core member in the opening direction of the case body is more effective for stabilizing the gap distance and its position. For this reason, the gap spacer forms a gap between the opposed end faces of a pair of core members, and also has a cylindrical shape as a whole, so that the shape of the concave portion conforms to the outer shape of the end of each core member. It has a shape. Thereby, the gap spacer can also suppress the displacement of the core member in the opening direction of the case body, and can stabilize the interval and position of the gap formed by positioning the pair of core members. The opening direction is not limited to the direction from the inside of the case body to the opening side, but may be the direction from the opening side to the inside.

Further, the gap spacer not only positions the pair of core members as described above, but also contributes to the positioning of the circuit board. Positioning of the circuit board is achieved through cooperation between the structure of the gap spacer and the structure of the circuit board. That is, the circuit board has a partially ring-shaped board member, and electronic components mounted so as to protrude into the gap from the mounting surface of the board member. The electronic component can have a magnetic sensing element inside. A positioning hole is formed in the substrate member at a position overlapping the gap spacer, and the positioning hole penetrates the substrate member in the thickness direction.

A recess between gaps and a positioning protrusion are provided on the gap spacer side. Of these, the inter-gap recess is formed by recessing a portion corresponding to the gap between the end surfaces of the pair of core members in the direction in which the substrate members are superimposed, so that the electronic component can be received therein. In addition, the positioning protrusion is formed so as to protrude in the direction of the substrate members at a position where the substrate members are overlapped. Position the electronic component within the gap.

As a result, (1) positioning of the core member by the pressing member and the gap spacer, (2) stabilization of the gap distance and position, and (3) positioning and stabilization of the magnetic sensing element within the gap are realized at the same time. It becomes possible. Therefore, variations in detection accuracy of the current detector can be suppressed, and stable performance can be exhibited over a long period of time.

The current detector of the present invention can also have the following preferred modes.
(1) In the gap spacer, a pair of recesses are formed in symmetrical shapes on both sides of the inter-gap recess, and a pair of positioning protrusions are formed in symmetrical positions around the inter-gap recess. It is a mode.

In the above-described mode, in the process of assembling the current detector, the concave portion of the gap spacer and the positioning protrusion can be combined with the core member in any direction with respect to the inter-gap concave portion. There is no need to confirm, and work efficiency can be improved.

(2) The gap spacer can also have an abutment portion and an opening portion. The abutting portion abuts on the end face of the core member at the deep position in the receiving direction of the recess, and positions the core member at the end face while being pushed by the pressing member in the case body. Further, the open portion allows the contact state between the contact portion and the end surface of the core member to be visually recognized from the outside through the inter-gap recessed portion in a state in which the recessed portion and the inter-gap recessed portion are opened.

According to the above aspect, it is possible to visually confirm that the pair of core members are correctly positioned by the gap spacer in the process of assembling the current detector. As a result, the degree of completeness of the assembly is enhanced, and it is possible to contribute to the improvement of quality.

(3) The circuit board may have passage holes formed in the board member. The passage hole is formed in a region that overlaps with at least one of the core member and the gap spacer, and penetrates in the thickness direction to serve as a passage for the filling material that fills the case body.

According to the above aspect, in the process of assembling the current detector, the filling material filled in the case body can be easily spread between the circuit board and the gap spacer or between the core member, and the filling efficiency can be improved. can. In addition, since the passage hole also serves as an air vent before the filler passes through, it is possible to suppress the occurrence of insufficient filling due to air pockets.

According to the present invention, the core can be stably positioned.

FIG. 3 is a perspective view showing an assembled state of the current sensor 100; FIG. 3 is a perspective view showing an assembled state of the current sensor 100; 2 is an exploded perspective view schematically showing the configuration of current sensor 100. FIG. 2 is an exploded perspective view schematically showing the configuration of current sensor 100. FIG. 4 is a perspective view showing the detailed structure of a gap spacer 106; FIG. 4 is a front view showing a positioning state of the core member 104; FIG. FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 5; FIG. 6 is a cross-sectional view taken along line VI-VI of FIG. 5; FIG. 6B is a cross-sectional view along line VII-VII of FIG. 6A; 4 is a perspective view showing an insertion trajectory of a spring spacer 108; FIG. 4 is a perspective view showing an insertion trajectory of a spring spacer 108; FIG. FIG. 4 is a continuous view showing the insertion trajectory of the spring spacer 108 according to parts; FIG. 4 is a continuous view showing the insertion trajectory of the spring spacer 108 according to parts; FIG. 4 is a continuous view showing the insertion trajectory of the spring spacer 108 according to parts; FIG. 4 is a continuous view showing the insertion trajectory of the spring spacer 108 according to parts; FIG. 4 is a continuous view showing the insertion trajectory of the spring spacer 108 according to parts; FIG. 4 is a continuous view showing the insertion trajectory of the spring spacer 108 according to parts; FIG. 4 is a continuous view showing the insertion trajectory of the spring spacer 108 according to parts; FIG. 4 is a continuous view showing the insertion trajectory of the spring spacer 108 according to parts; FIG. 4 is a continuous view showing the insertion trajectory of the spring spacer 108 according to parts; FIG. 4 is a continuous view showing the insertion trajectory of the spring spacer 108 according to parts; FIG. 3 is a diagram showing a housed state of a circuit board 110; FIG. 3 is a diagram showing a housed state of a circuit board 110;

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, a magnetic proportional current sensor is used as an example of a current detector, but the present invention is not limited to this, and may be a magnetic balance current sensor or a flux gate. type current sensor.

FIG. 1 is a perspective view showing an assembled state of the current sensor 100 of one embodiment. 2 and 3 are exploded perspective views schematically showing the configuration of the current sensor 100 of one embodiment. Note that the perspective view of FIG. 1B is obtained when the current sensor 100 shown in FIG. 1A is shown from a different direction (180° opposite side). 2 and 3, the oblique direction is reversed.

〔overall structure〕
As shown in FIGS. 2 and 3, the current sensor 100 mainly includes a case body 102, a core member 104, a gap spacer 106, a spring spacer 108 and a circuit board 110, which are shown in FIGS. The current sensor 100 is assembled on the assembly axis AX shown. Further, the core member 104 is assembled after being combined with the gap spacer 106 by bringing the assembly axis AX to the center.

Then, the current sensor 100 is in one usage form as shown in FIG. 1 to 3 show the current sensor 100 in a posture assuming this type of use, in which a primary conductor (such as a busbar) (not shown) that conducts the current to be detected is inserted laterally (horizontally). It is assumed that Further, FIG. 1 shows the inside of the case body 102 sealed with the filler 105, but the filler 105 is not shown in FIGS. Note that the current sensor 100 may be used in other postures (for example, a flat posture, a small end standing posture, an inverted posture, etc.).

[Case body]
The case body 102 has a rectangular container shape with one end face open (open) and the other end face closed. Further, the case body 102 has a rectangular insertion portion 103 formed in its center, so that the container shape of the case body 102 as a whole has a rectangular annular shape. The insertion portion 103 penetrates through the center of the current sensor 100 in the assembled state in the thickness direction, and the primary conductor (not shown) extends in the insertion portion 103 in the lateral direction ( horizontal direction). For this reason, the case body 102 is integrally formed with a flange 102a for installing the current sensor 100 in an upright position. A bracket portion 102b is formed in the case body 102 so as to extend from the insertion portion 103, and the case body 102 is screwed to a primary conductor (not shown) at the bracket portion 102b.

[Core member]
The core members 104 are arranged in pairs around primary conductors (not shown). The pair of core members 104 are each formed in a horizontal U shape (so-called UU shape), and are rectangular with both end surfaces (that is, both end surfaces) 104a, which are tip surfaces of the U shape, facing each other. are arranged in a ring to constitute one magnetic core. At this time, gaps are formed between the end surfaces 104a of the pair of core members 104 (at two locations), which will be described later. A soft magnetic material (for example, ferrite, silicon steel, etc.) is used for each core member 104 , and when a current to be detected passes through a primary conductor (not shown), a magnetic field generated around it is converged on the pair of core members 104 . be. At this time, the pair of core members 104 forms a magnetic field convergence path (magnetic circuit, magnetic path, magnetic flux path) in the circumferential direction. A ground electrode 104 b is welded to each core member 104 .

[Gap spacer]
The gap spacer 106 is, for example, a structural part made of resin, and has a rectangular tubular shape as a whole here. As an example, the rectangular tubular shape follows the outer shape (here, prismatic shape) of the end portion of the core member 104. If the outer shape of the end portion of the core member 104 is cylindrical, the gap spacer 106 may have a cylindrical shape, and the gap spacer 106 may have a polygonal tubular shape if it has a polygonal prism shape other than a quadrangular prism.

[Recess]
Also, the gap spacers 106 are arranged at positions (here, two positions) where the pair of core members 104 face their end faces 104a. Each gap spacer 106 has a pair of recesses 106a on both sides when viewed in the direction in which the pair of core members 104 are combined (the direction in which the end faces 104a face each other). By doing so, the opening faces are facing back (in opposite directions). These recesses 106a also have a bag shape that conforms to the outer shape of the end of the core member 104, and when the end of the core member 104 is inserted into the corresponding recess 106a, the inner surface of the recess 106a is It conforms to the outer surface at the end of the core member 104 . Also, the end surface 104a of the core member 104 abuts against each recess 106a. The concave portion 106a will be further described later.

[Recess between gaps]
Further, the gap spacer 106 has an inter-gap concave portion 106b at a central position when viewed in the combination direction of the pair of core members 104. As shown in FIG. The inter-gap recess 106b is located between the pair of recesses 106a on both sides and is recessed from the outer surface of the gap spacer 106 in the assembly axis AX direction. The inter-gap concave portion 106b will also be described later.

[Pressing member]
A pair of spring spacers 108 correspond to the pair of core members 104 and are housed in the case body 102 together with the core members 104 . The spring spacer 108 is supported by the case body 102 in an accommodated state, and generates a force that presses one corresponding core member 104 toward the other core member 104 (a pair of core members 104 are attached in a direction facing each other). force). The spring spacer 108 has two legs 108b and two latching claws 108c formed at each end edge of a rectangular plate-like portion (no reference numeral), and a spring portion 108a at one long side edge of the plate-like portion. is formed. The leg portion 108b, the latching claw 108c, and the spring portion 108a extend from the plate-like portion toward the inside of the case body 102, and when the current sensor 100 is assembled, the leg portion 108b, the latching claw 108c, and the spring portion 108a extend. is arranged between the outer peripheral surface of the core member 104 and the inner surface of the case body 102 . Therefore, the spring spacer 108 is housed in the case body 102 so as to cover one side surface and the outer peripheral surface of the core member 104 from the one end face opening side of the case body 102 . In this housed state, spring spacer 108 positions core member 104 at a predetermined position. Positioning by the spring spacer 108 will be further described later.

[Circuit board]
The circuit board 110 also has a shape that matches one end face opening of the case body 102 and one side face of the core member 104, but is not connected in a ring shape, and is like a holed rectangular shape divided in half. It has a character shape. That is, the circuit board 110 has an insulating board member having a U-shaped partial ring shape, and wiring patterns and via holes (not shown) are formed on both mounting surfaces and inner layer portions of the board member. Two ASICs 112 are mounted through holes on one mounting surface of the substrate member, and a connector 110a is mounted through holes on the other mounting surface.

The ASIC 112 is an electronic device in which a circuit including a magnetic detection element such as a Hall sensor is integrated. In the assembled state of the current sensor 100 , the circuit board 110 is accommodated in the case body 102 so as to overlap the plate-like portion of one spring spacer 108 . In this housed state, the two ASICs 112 are arranged in the inter-gap recess 106 b of the gap spacer 106 . A circuit for detecting the current to be detected using the output signal of the ASIC 112 is formed on the circuit board 110 . Therefore, various electronic components (chip components, ICs, etc.) (not shown) are also mounted on each mounting surface of the circuit board 110 (substrate member). A through hole 110b for the ground electrode 104b is formed in the circuit board 110 as appropriate. Note that the circuit board 110 may be formed in an annular shape.

[Detailed structure]
FIG. 4 is a perspective view showing the detailed structure of the gap spacer 106. As shown in FIG. As described above, the gap spacer 106 has a rectangular tubular shape as a whole and has a pair of concave portions 106a on both sides inside. Between the pair of concave portions 106a on both sides, the inter-gap concave portions 106b are formed so as to be recessed (gouged) from the outer surface. The pair of concave portions 106a on both sides are formed in a shape that is symmetrical (for example, point-symmetrical) about the inter-gap concave portion 106b.

[Contact part]
Each concave portion 106a has a box-like bag shape, and the inside of the concave portion 106a has a shape (a so-called bottomed shape) where the inside of the concave portion 106a abuts (dead end). More specifically, a rib-shaped contact portion 106d is formed at a position (deep bottom) that abuts each recess 106a. Position the core member 104 . Although not shown in FIG. 4, the abutting portion 106d is formed in, for example, a square shape or a square shape when viewed from the opening side of the concave portion 106a. As a result, the contact range with the end surface 104a can be widened, and the positioning of the core member 104 can be made more reliable.

[Opening part]
However, the surface that abuts the concave portion 106a is not closed and is partially formed with a window-like opening. This open portion serves as an open portion 106c, and the open portion 106c is in a state of partially opening the recess 106a and the inter-gap recess 106b. As a result, the contact portion 106d can be visually recognized, and when the core member 104 is assembled, the contact state between the contact portion 106d and the end face 104a can be visually recognized from the outside. Accordingly, in the process of assembling the current sensor 100, an operator or the like can visually confirm through the opening 106c that the core member 104 (end surface 104a) is correctly positioned.

[Positioning protrusion]
A protruding positioning protrusion 106e is formed on the outer surface of the gap spacer 106 at a position where the circuit board 110 is superimposed during assembly, and the positioning protrusion 106e projects toward the circuit board 110 in the assembled state. there is A pair of positioning projections 106e are formed at symmetrical (for example, point-symmetrical) positions about the inter-gap recess 106b. Positioning of the circuit board 110 by the positioning protrusion 106e will be further described later.

In addition, a notch 106f is formed in the gap spacer 106 from the opening edge of each recess 106a toward the inter-gap recess 106b. It has wideness and breadth. In addition, the notches 106f are formed symmetrically (for example, point-symmetrically) on both sides in the same way that the pair of recesses 106a are symmetrical.

[Universal shape]
As is clear from FIG. 4, the shape of the gap spacer 106 remains the same (unchanged) even when it is rotated (reversed) by 180° about the assembly axis AX. Further, there are two positions where the end surfaces 104a of the pair of core members 104 face each other, and the gap spacer 106 can be used in common at both positions. Thereby, the gap spacer 106 can be used as a common universal component in the assembly process, and workability and work efficiency can be improved.

[Positioning state]
FIG. 5 is a front view showing the positioning state of the core member 104. FIG. Note that the circuit board 110 is not shown in FIG.

[Gap formation]
The pair of core members 104 are housed in the case body 102 and are annularly arranged with opposite end faces 104a. Both of the pair of spring spacers 108 are fixed to the case body 102 in a state of being housed in the case body 102, but the spring portion 108a does not contact the case body 102 and the plate-like portion is fixed to the fixed end. can be elastically deformed as At this time, if the facing direction of the pair of core members 104 is the direction of arrow A1 in FIG. At the same time, the restoring force (repulsive force) generates a force that presses the pair of core members 104 together in the arrow A1 direction. As a result, the end surface 104a of the core member 104 is held in contact with the contact portion 106d in each recess 106a of the gap spacer 106, and a gap of a specified distance is formed between the opposing end surfaces 104a. .

[Positioning in the opposite direction]
In addition, the pair of core members 104 are positioned in the facing direction (arrow A1 direction) by the gap spacer 106 and the spring spacer 108 while being accommodated in the case body 102 . That is, the pair of core members 104 are pushed in the opposing direction by the spring portion 108a of the spring spacer 108, and are abutted against the contact portion 106d in the concave portion 106a of the gap spacer 106, thereby moving the pair of core members 104 in the opposing direction in the case body 102. Positioning is achieved by suppressing the displacement to

[Positioning in directions other than opposing direction]
Positioning of the core member 104 in directions other than the facing direction is performed by ribs 102f on the inner surface of the case body 102, for example. The ribs 102f are formed at a number of positions along the inner surfaces of the outer peripheral walls facing each other in a direction perpendicular to the facing direction of the pair of core members 104. It extends like a streak toward the end face opening. Each core member 104 is guided by a large number of ribs 102f at its edge on the opposite side (deep side) of the opening when housed in the case body 102, and is positioned in a direction perpendicular to the facing direction along the opening surface. . A large number of

ribs

102c and 102d are also formed on the inner surface of the case body 102, which will be described later.

[Displacement Suppression of Core Member]
The gap spacer 106 forms the gap as described above, and in addition to positioning the pair of core members 104 in the direction facing each other, suppresses the displacement of the core members 104 in the opening direction of the case body 102 . there is This point will be further described below.

FIG. 6 is a cross-sectional view (a cross-sectional view taken along line VI-VI in FIG. 5) showing an example of a structure for suppressing displacement of the core member 104 by the gap spacer 106. As shown in FIG. Here, FIG. 6A shows a structural example of this embodiment, and FIG. 6B shows a structural example of a comparative example. A structural example of this embodiment will be described below in comparison with a comparative example.

[Structural example of the present embodiment]
FIG. 6A: As described above, the pair of core members 104 are pressed in opposing directions by the spring portions 108a from the respective outer surfaces opposite to the respective end surfaces 104a. At this time, since the spring portion 108a is in line contact with the outer surface of the core member 104, each core member 104 has a contact point P with the spring portion 108a. , the possibility of tilting (rotational) displacement in the direction of the opening is conceivable. This is also due to the fact that the spring portions 108a press the pair of core members 104 against each other from both sides. However, in the case of the structural example of the present embodiment, such an inclination displacement of the core member 104 is suppressed because the concave portion 106a of the gap spacer 106 is shaped like a bag.

[Structure example of comparative example]
FIG. 6B: A comparative structural example is one in which a block-shaped or plate-shaped spacer 60 is arranged in the gap. Even in this case, if the pair of core members 104 are pressed against each other by the spring portions 108a similar to those of the present embodiment, it is considered possible to form a gap with the spacer 60 and position the core members 104. FIG. However, on both sides of the gap, since the ends of the core member 104 are free in the opening direction of the case body 102, there is a possibility that the core member 104 is greatly inclined (rotationally) displaced about the fulcrum P in the opening direction. is high. In this case, the gap interval and gap position fluctuate, and the current detection accuracy tends to become unstable.

In this regard, in the case of the structural example of this embodiment (FIG. 6A), the end of the core member 104 is gripped in the shape of a bag by the inner surface of the recess 106a and the contact portion 106d. Tilt is constrained and displacement can be constrained as described above. As a result, the distance between the gaps formed between the end faces 104a can be stably maintained, and the deviation of the position of the gap from the normal position can be reliably suppressed, so that the current detection accuracy can be stabilized. can be done.

[Positioning of gap spacer]
FIG. 7 is a cross-sectional view (a cross-sectional view taken along line VII-VII in FIG. 6A) showing an example of the positioning structure of the gap spacer 106 inside the case body 102. As shown in FIG. The gap spacer 106 is positioned in the facing direction of the pair of core members 104 by ribs 102 c on the inner surface of the case body 102 . Other ribs (no reference numeral) are formed between the two ribs 102c paired in the opposite direction, and these ribs also position the gap spacer 106 in the direction along the end face 104a of the core member 104. It is 7 shows the cross-sectional shape of the contact portion 106d, it can be seen that the contact portion 106d contacts the end surface 104a at a plurality of locations within the recess 106a.

Also, in the direction along the end surface 104a of the core member 104, a certain amount of clearance is provided between the core member 104 and the inner surface of the recess 106a. As a result, the workability of inserting the end of the core member 104 into the recess 106a is improved, and the efficiency can be improved.

[Spring spacer insertion trajectory]
FIG. 8 is a perspective view showing an insertion trajectory of spring spacer 108 into case body 102 in the process of assembling current sensor 100 . Among them, FIG. 8A shows the state before insertion of the spring spacer 108, and FIG. 8B shows the state after insertion.

In the process of assembling the current sensor 100, the spring spacer 108 is assembled so as to overlap the core member 104 with one end face opening of the case body 102 facing upward. Further, the leg portion 108b, the latching claw 108c and the spring portion 108a of each spring spacer 108 are inserted between the outer peripheral surface of the core member 104 and the inner surface of the case body 102 after the core member 104 is accommodated. In such an insertion trajectory of the spring spacer 108, the insertion of the leg portion 108b is guided by the ribs 102d on the inner surface of the case body 102. As shown in FIG. Further, in the insertion trajectory, the leg portion 108b, the latching claw 108c and the spring portion 108a are inserted in order with a time lag.

FIG. 9 is a continuous diagram showing the insertion trajectory of the spring spacer 108 for each part. Among them, FIG. 9A is a plan view of the case body 102 and the spring spacer 108 viewed in the insertion direction, and FIGS. 9C1 to 9C3 are sectional views showing the insertion trajectory of the spring portion 108a (CC sectional view in FIG. 9A), and FIGS. DD sectional view).

[Initial stage of insertion]
FIG. 9B1: At the initial stage of inserting the spring spacer 108, the tip portion of the leg portion 108b is first inserted along the inner surface of the case body 102 and inserted between the two ribs 102d at each position. As a result, the insertion start position of the spring spacer 108 with respect to the one end face opening of the case body 102 can be easily obtained.
FIGS. 9C1 and 9D1: On the other hand, when the tip of the leg portion 108b is inserted in the initial stage of insertion, the other spring portion 108a and latching claw 108c do not come into contact with the case body 102 or the core member 104. FIGS.

[Middle stage of insertion]
Figure 9B2: Leg 108b is inserted between two more ribs 102d.
FIG. 9C2: The spring portion 108a extends so as to be inclined toward the center from its base end, but its tip portion is warped in the opposite direction to the facing direction of the core member 104. FIG. This warped portion is located inside the outer peripheral edge of the core member 104 in the opposing direction. Therefore, the warped portion of the spring portion 108a contacts the outer peripheral edge of the core member 104 in the middle stage of insertion.

FIG. 9D2: On the inner surface of the case body 102, a projecting hooking portion 102e is formed corresponding to the position where the hooking claw 108c is inserted. functions at the end of Therefore, in the middle stage, the hooking claw 108c and the hooking portion 102e are not yet in contact with each other.

[Late stage of insertion to completion]
FIG. 9B3: The leg portion 108b is further inserted deeply between the two ribs 102d, and when the insertion is completed, the plate-like portion of the spring spacer 108 comes into contact with the ribs 102d and is positioned in the opening direction of the case body 102. . Moreover, although the leg portion 108b contacts the inner surface of the case body 102, it does not contact the core member 104 even after the insertion is completed.

FIG. 9C3: In addition, the spring part 108a is pushed back against the outer surface of the core member 104 and elastically deformed in the opposite direction to the opposing direction, and the restoring force presses the core member 104 in the opposing direction. Looking at the pair of spring spacers 108 on both sides, the pair of spring portions 108a are bent and deformed so as to expand in the opposite direction of the opposing direction. When the insertion is completed, the pair of spring portions 108a on both sides presses the pair of core members 104 in the opposite direction as described above. At this time, since the insertion position of the entire spring spacer 108 in the planar direction (the direction along the opening surface of the case body 102) is determined at the initial stage, the load and deflection amount of the spring portion 108a can be stably managed.

FIG. 9D3: At the final stage, the tip portion (turned portion) of the latching claw 108c contacts the latching portion 102e, and as the insertion progresses, the latching claw 108c bends toward the core member 104 (elastic deformation). do). At this time, since the insertion start position of the spring spacer 108 is determined at the initial stage of the insertion process, it is possible to stably manage the load and the amount of deflection received by the latching claw 108c. Then, when the tip portion (turned portion) of the hooking claw 108c passes the hooking portion 102e, the hooking hook 108c is restored from the bent state, and the tip portion (turned portion) is caught by the hooking portion 102e and inserted. Completed. As a result, the spring spacer 108 is prevented from falling off from the case body 102, and the core member 104 is held.

[Positioning of circuit board]
10A and 10B are diagrams showing the accommodation state of the circuit board 110. FIG. 10A is a plan view of the case body 102 viewed from the opening direction, and FIG. 10B is a cross-sectional view perpendicular to the opening surface (BB cross-sectional view of FIG. 10A).

As described above, the circuit board 110 is accommodated from the opening side of the case body 102 so as to overlap the pair of core members 104 arranged in a ring. Since the substrate member of the circuit board 110 has a partial ring shape that matches the shape of the opening surface of the case body 102, the position of the circuit board 110 is roughly determined by inserting it through the opening. For proper positioning, the entire circuit board 110 needs to be precisely positioned. Such positioning of the circuit board 110 (board member) is performed in the direction along the opening surface of the case body 102 and the insertion direction (opening direction).

[Positioning along the opening surface]
FIG. 10A: As described above, the gap spacer 106 is formed with the positioning projection 106e, and the circuit board 110 is formed with the positioning hole 110c at the position corresponding to the positioning projection 106e. In this embodiment, two gaps are formed between the core members 104, and the gap spacers 106 are arranged in each gap, so that the circuit board 110 is also formed with two positioning holes 110c. . The positioning hole 110c is formed through the board member in the thickness direction, and when the circuit board 110 is accommodated (inserted state), the positioning protrusion 106e is inserted (so-called fitted) into the positioning hole 110c. At this time, the circuit board 110 is positioned in the opposing direction by ensuring only a minimum clearance in the opposing direction of the pair of core members 104 between the positioning hole 110c and the positioning projection 106e.

In addition, the direction orthogonal to the facing direction of the core member 104 along the opening surface of the case body 102 is positioned, for example, based on the relationship between the outer edge shape of the circuit board 110 (board member) and the inner surface shape of the case body 102 . That is, the circuit board 110 is positioned in a direction perpendicular to the facing direction of the core member 104 because the outer edge of the board member is formed along the inner wall surface of the case body 102 . Furthermore, one of the two positioning holes 110c has a minimum clearance from the positioning projection 106e also in the direction perpendicular to the opposing direction, so that the insertion (fitting) relationship of these will also be positioned.

[Positioning in opening (insertion) direction]
10A and 10B: Further, the opening direction of the case body 102, that is, the insertion direction of the circuit board 110 is positioned by contact with the

ribs

102c and 102d on the inner surface of the case body 102. FIG.

As a result, the ASIC 112 is also positioned with respect to the inter-gap recess 106 b, that is, the gap between the pair of core members 104 . In this case, the gap spacer 106 positions the end surface 104a of the core member 104 to define the position of the gap, and also positions the ASIC 112 with respect to the defined gap. It is possible to detect a current to be detected that functions properly.

[passage hole]
In this embodiment, the circuit board 110 further has the following configuration.
As shown in FIGS. 10A and 10B, a substrate member of the circuit board 110 is formed with a large number of passage holes 110d arranged in rows. The passage hole 110d penetrates the board member in the thickness direction, so that the board member of the circuit board 110 and the core member 104 are in communication with each other inside the case body 102 through the passage hole 110d. Therefore, when the filler 105 is filled into the case body 102 in the assembly process, the filler 105 can flow through the passage hole 110d, so that the filling efficiency can be enhanced. In addition, since the passage hole 110d also functions as an air vent during the filling process, it is possible to suppress the occurrence of a filling failure due to an air pool after filling.

According to the current sensor 100 of the embodiment described above, the following advantages are obtained.
(1) In the case of a structure in which a plurality of core members 104 are combined, it is difficult to bring the gap distance closer to the required value due to variations in the positional accuracy of each core member 104. However, in this embodiment, the spring portion 108a of the spring spacer 108 , the two core members 104 are pressed against each other and positioned by the concave portion 106a (contact portion 106d) of the gap spacer 106, so that the gap distance can be maintained at the required value.

(2) Since the positioning of the spring spacer 108 and the gap spacer 106 works effectively even after the product is shipped, even if the current sensor 100 is affected by the environment in which it is used (for example, temperature changes), the pressing force from the spring portion 108a does not affect the gap. The detection accuracy can be maintained for a long period of time because it acts in the direction of maintaining the required distance.

(3) The concave portion 106a of the gap spacer 106 is bag-shaped (box-shaped with a bottom), and the end portion of the core member 104 is received in the concave portion 106a to suppress displacement. The portion 108a serves as a fulcrum and tilts in a direction other than the facing direction (opening direction of the case body 102).

(4) Thereby, the detection accuracy of the current sensor 100 can be maintained high, and the reliability can be improved.

The present invention can be modified in various ways without being restricted by the above-described embodiment. For example, the overall shape of current sensor 100 may be other than rectangular annular.

Further, the case body 102 may be divided into a plurality of parts, or may be provided with an openable lid. Further, the shape of the case body 102 and the arrangement of ribs can be appropriately changed according to the shapes of the core member 104, the gap spacer 106, the spring spacer 108, etc., which are used, and the number of them is also the example given in the embodiment. is not limited to

The gap spacer 106 is arranged at the central position of the core member 104 in the opposing direction to form a gap, but the gap may be formed by the gap spacer 106 at another position. Also, the number of gaps may be more than two. Even in this case, the spacing and positions of the respective gaps can be properly maintained by positioning them while pressing them in the opposite direction by the spring spacers 108 .

The entire gap spacer 106 does not have to have the same rectangular tubular shape. For example, the outer shape of the concave portion 106a may be a cylindrical shape matching the outer shape of the end portion of the core member 104, and the portion corresponding to the inter-gap concave portion 106b may have a different shape.

The positioning of the circuit board 110 may be performed using means other than the fitting between the positioning protrusion 106e and the positioning hole 110c. Also, the number of positions where the circuit board 110 is positioned by the gap spacers 106 may be three or more.

In addition, the structures shown in the drawings in the embodiments etc. are merely preferable examples, and it is possible to suitably implement the present invention by adding various elements to the basic structure or by partially substituting. Not even.

The present invention provides core positioning technology.

100 Current sensor 102 Case body 104 Core member 106 Gap spacer 108 Spring spacer 110 Circuit board

Claims

a pair of core members arranged in an annular manner around a primary conductor through which a current to be detected conducts, with the end surfaces of both ends facing each other;
a case body having an insertion portion through which the primary conductor can be inserted, and housing the pair of core members therein through an annular opening formed around the insertion portion;
a pressing member that generates a force that presses the pair of core members in opposite directions from the respective outer side surfaces opposite to the respective end surfaces while being housed in the case body;
The pair of core members are accommodated in the case body and are arranged at locations where the end faces of the pair of core members face each other, and the pair of core members facing each other are placed in a pair of recesses formed with the opening faces facing back to each other. a gap spacer that forms a gap of a specified distance between the facing end surfaces of the pair of core members in a state where the end portions are received and suppresses displacement of the core members in an opening direction of the case body;
and a circuit board on which is formed a detection circuit that detects a current to be detected by using the magnetic detection element arranged in the gap while being accommodated in the case body.
The current detector of claim 1, wherein
The circuit board is
a partially ring-shaped substrate member disposed in the case body so as to overlap the core member and the gap spacer in the opening direction of the case body;
an electronic component having the magnetic detection element mounted so as to protrude into the gap from the mounting surface of the substrate member;
a positioning hole penetrating in the thickness direction at a position overlapping the gap spacer of the substrate member;
The gap spacer is
an inter-gap recess that is formed by recessing a portion corresponding to the gap between the end surfaces of the pair of core members in the direction in which the substrate members are superimposed, and that is capable of receiving the electronic component therein;
It is formed so as to protrude in the direction of the substrate members at a position where the substrate members are overlapped, and is inserted into the positioning hole in the overlapping state of the substrate members to relatively position the substrate members in the gap. and a positioning protrusion for positioning the electronic component.
The current detector of claim 2, wherein
The gap spacer is
A pair of recesses are formed in a symmetrical shape on both sides with respect to the inter-gap recess, and a pair of positioning protrusions are formed at symmetrical positions with respect to the inter-gap recess. current detector.
The current detector according to claim 2 or 3,
The gap spacer is
a contact portion that contacts the end face of the core member at a depth position in the receiving direction in the recess and positions the core member in the state of being pushed by the pressing member in the case body at the end face;
An open portion is provided so that a state of contact between the contact portion and the end surface of the core member can be visually recognized from the outside through the inter-gap recess in a state where the recess and the inter-gap recess are opened. A current detector characterized by:
The current detector according to any one of claims 2 to 4,
The substrate member is
A current detector comprising a passage hole formed in a region overlapping at least one of the core member and the gap spacer and penetrating in a thickness direction to serve as a passage for a filler filled in the case body. .