Current sensor and manufacturing method therefor

Abstract

In the present invention, a core (20) comprises: a first gap formation part (21); a second gap formation part (22) that forms a gap (201) between the first gap formation part (21) and the second gap formation part (22); a first core lateral part (23); a second core lateral part (24); a first gap-side connection part (25) that is disposed between the first gap formation part (21) and the first core lateral part (23) and that has a rounded shape; a second gap-side connection part (26) that is disposed between the second gap formation part (22) and the second core lateral part (24) and that has a rounded shape; and a core bottom part (27). Portions of the first gap formation part (21) and the second gap formation part (22), the portions being on the side opposite to the core bottom part (27) side, and portions of a core outer surface (20b) of the first gap-side connection part (25) and the second gap-side connection part (26), the portions being on the side opposite to the core bottom part (27) side, have sections exposed from a case (50).

Description

Current Sensor and Method for Manufacturing the Same Cross - Reference to Related Applications

[0001] This application is based on Japanese Patent Application No. 2024 - 189856 filed on October 29, 2024, the contents of which are incorporated herein by reference.

[0002] This disclosure relates to a current sensor and a method for manufacturing the same.

[0003] Conventionally, a current sensor has been proposed in which a core having a C - shaped gap is arranged around a bus bar through which current flows, and a detection unit is arranged in the gap of the core (see, for example, Patent Document 1). Specifically, in this current sensor, the core is insert - molded and integrated into a case made of a resin material. And in this current sensor, the portion of the core that forms the gap is in a state of being exposed from the case so that the gap of the core is less likely to deform due to the expansion and contraction of the case.

[0004] Japanese Unexamined Patent Application Publication No. 2009 - 42003

[0005] However, according to the study by the present inventors, simply exposing the portion of the core that forms the gap from the case may not be sufficient to cope with the expansion and contraction of the case, and it has been confirmed that the gap may change. And when the gap of the current sensor changes, the detection accuracy decreases.

[0006] An object of this disclosure is to provide a current sensor and a method for manufacturing the same that can suppress a decrease in detection accuracy.

[0007] According to one aspect of this disclosure, the current sensor comprises a core that collects a magnetic field based on the current when an electric current flows through it, a detection unit that outputs a detection signal corresponding to the magnetic field, and a case made of resin to which the core and the detection unit are assembled, wherein the core and the case are integrally molded, and the core has a core hole, a core inner surface which is the surface on the core hole side, a core outer surface which is the surface opposite to the core inner surface, a first gap forming portion having a first end face and extending in a first direction, a second gap forming portion having a second end face that faces the first end face and forms a gap between it and the first end face and extends in a first direction, a first core lateral portion extending in a second direction intersecting the first direction, a second core lateral portion extending in a second direction, and the portion of the first gap forming portion opposite to the first end face and the first core lateral portion. The core comprises a first gap-side connecting portion, which is positioned between the first and second gap-forming portions and has a curved, rounded shape; a second gap-side connecting portion, which is positioned between the portion of the second gap-forming portion opposite to the second end face and the second core side portion and has a curved, rounded shape; a core bottom portion extending in the first direction; a first bottom-side connecting portion, which is positioned between the first core side portion and the core bottom portion and has a curved, rounded shape; and a second bottom-side connecting portion, which is positioned between the second core side portion and the core bottom portion and has a curved, rounded shape. The portions of the first gap-forming portion and the second gap-forming portion opposite to the core bottom portion, and the portions of the outer surface of the core in the first gap-side connecting portion and the second gap-side connecting portion opposite to the core bottom portion, have portions that are exposed from the case.

[0008] According to this design, the core is exposed from the case at the portion opposite the core bottom side in the first and second gap forming portions, and at the portion of the core's outer surface opposite the core bottom side in the first and second gap side connecting portions. This makes it difficult for stress due to the expansion and contraction of the case to be applied, thereby suppressing deformation of the core. In particular, in this current sensor, the outer surfaces of the core at the first and second gap side connecting portions, which are rounded portions that are easily deformed and whose deformation easily changes the gap spacing, are exposed from the case. Therefore, compared to the case where only the first and second gap forming portions are exposed from the case, a decrease in detection accuracy can be suppressed.

[0009] Furthermore, according to another aspect of this disclosure, the method for manufacturing the current sensor involves preparing a core and forming a case in which the core is insert-molded by pouring molten resin into a mold. In preparing the core, a core having a partially thickened wall portion is prepared, and in forming the case, the molten resin is poured into the mold such that the molten resin first reaches the walled portion of the core, and the flow direction of the molten resin is along the direction normal to the surface direction of the walled portion.

[0010] According to this design, the molten resin first reaches the thickened portion, and the flow direction of the molten resin is aligned with the direction normal to the surface direction of the thickened portion. As a result, the molten resin flows along the core after colliding with the thickened portion, thus suppressing deformation of the core by the molten resin. Therefore, it is possible to manufacture a current sensor that suppresses a decrease in detection accuracy.

[0011] Furthermore, according to another aspect of this disclosure, the method for manufacturing the current sensor involves preparing a core and forming a case in which the core is insert-molded by pouring molten resin into a mold, wherein the method for forming the case involves arranging the core in the mold such that a part of the outer surface of the core is located at the highest point in the vertical direction, and pouring molten resin into the mold such that the molten resin reaches the outer surface of the core before the inner surface of the core at the highest point in the vertical direction.

[0012] According to this method, the molten resin reaches the outer surface of the core before the inner surface of the core at the uppermost part in the vertical direction. This suppresses core floating and positional misalignment. Therefore, it is possible to manufacture a current sensor that suppresses a decrease in detection accuracy.

[0013] This is a perspective view of the current sensor in the first embodiment. This is a cross-sectional perspective view of the current sensor. This is a cross-sectional view along the line III-III in Figure 1. This is an enlarged view of part IV in Figure 3. This is a diagram illustrating the configuration of the core and busbar. This is a plan view of the core as seen from the direction of arrow VI in Figure 5. This is a diagram illustrating the configuration of the detection unit. This is a plan view as seen from the direction of VIII in Figure 1. This is a plan view showing the case and core. This is a cross-sectional view along the line X-X in Figure 9. This is an enlarged view of the vicinity of the core in the second embodiment. This is an enlarged view of the vicinity of the core in a modified example of the second embodiment. This is an enlarged view of the vicinity of the core in a modified example of the second embodiment. This is an enlarged view of the vicinity of the core in the third embodiment. This is a plan view showing the case and core in the fourth embodiment. This is a perspective view of the core in the fifth embodiment. This is a plan view showing the case and core in the fifth embodiment. This is an oblique cross-sectional view of the current sensor in the sixth embodiment. This is a cross-sectional view of the current sensor in the sixth embodiment. This is a cross-sectional view of the vicinity of the terminal in the seventh embodiment. This is a cross-sectional view of the vicinity of the terminal in a modified example of the seventh embodiment. This is a perspective view of the current sensor in the eighth embodiment. This is a perspective view of the vicinity of the core in the eighth embodiment. This is a cross-sectional view of the vicinity of the exposed hole in the ninth embodiment. This is a cross-sectional view of the vicinity of the exposed hole in a modified example of the ninth embodiment. This is a cross-sectional view of the vicinity of the core in the tenth embodiment. This is a diagram illustrating the flow direction of the molten resin in the eleventh embodiment. This is a diagram illustrating the flow direction of the molten resin in the twelfth embodiment. This is a diagram illustrating core floating. This is an enlarged view of the vicinity of the core in another embodiment.

[0014] The embodiments of this disclosure will be described below with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be denoted by the same reference numerals.

[0015] (First Embodiment) The current sensor of the first embodiment will be described with reference to the drawings. The current sensor of this embodiment is preferably used, for example, to detect the current flowing to an inverter that drives a three-phase AC motor mounted on a vehicle (not shown).

[0016] In this embodiment, as shown in Figure 1 and other figures, the longitudinal direction of the case 50 described later will be referred to as the X-axis direction, one direction perpendicular to the X-axis direction will be referred to as the Y-axis direction, and the direction perpendicular to both the X-axis direction and the Y-axis direction will be referred to as the Z-axis direction. Note that the X-axis direction can also be referred to as the first direction, the Y-axis direction as the second direction, and the Z-axis direction as the third direction.

[0017] As shown in Figures 1 to 3, the current sensor comprises a busbar 10, a core 20, a detection unit 30, a substrate 40, a case 50, and a terminal 70. Figure 2 is a cross-sectional perspective view corresponding to the current sensor in Figure 1, but for ease of understanding, the vertical direction in the Z-axis direction is reversed compared to Figure 1, and the busbar 10 is omitted.

[0018] The busbar 10 is a plate-shaped member and is conductive, being made of copper or the like. The surface of the busbar 10 is plated as needed to prevent surface oxidation. The number of busbars 10 corresponds to the number of phases in the motor and inverter. In this embodiment, a current sensor for detecting the current flowing through an inverter driving a three-phase AC motor is used as an example, so there are three busbars 10. Each busbar 10 is spaced apart along the X-axis. Each busbar 10 is positioned such that its width direction in the planar direction of the plate-shaped member is approximately parallel to the X-axis direction, and its longitudinal direction in the planar direction of the plate-shaped member is approximately parallel to the Y-axis direction. In this embodiment, the busbar 10 corresponds to the current path. However, the current path is not limited to the busbar 10; any structure that constitutes a path through which current flows is acceptable.

[0019] In this embodiment, although not specifically shown, each busbar 10 is mounted and fixed to a common busbar mounting section at one end in the Y-axis direction. Each busbar 10 is then assembled to the case 50 by assembling a busbar mounting section collar (not shown) and the busbar mounting section of the case 50, which will be described later. Specifically, as will be described later, each busbar 10 is assembled so as to be inserted into a cavity 51 in the case 50 (i.e., a core hole 200 in the core 20). In addition, each busbar 10 has a fastening hole 11 formed on the other end opposite to the end that is fixed to the busbar mounting section, which is a through hole extending in the Z-axis direction. Each busbar 10 is then connected to each phase of the inverter via the fastening hole 11. As a result, current from each phase of the inverter flows through each busbar 10.

[0020] The busbar 10 in this embodiment is configured as follows, for example. Specifically, as shown in Figure 5, the busbar 10 has a busbar length XA1 in the X-axis direction of 10 to 25 mm, and a busbar length ZA1 in the Z-axis direction of 0.5 to 5 mm. A current of 0 to 3000 A flows through the busbar 10.

[0021] The core 20 is made of a soft magnetic material such as permalloy, grain-oriented electrical steel sheet, non-oriented electrical steel sheet, or wound core, and is formed in a C-shape to collect the magnetic field. The number of cores 20 corresponds to the number of busbars 10. In this embodiment, there are three busbars 10, so there are three cores 20. Each core 20 is C-shaped with a core hole 200 formed on the inside, and one core is placed for each busbar 10 so that each busbar 10 is inserted through the core hole 200. For this reason, each core 20 is spaced apart in the X-axis direction, similar to each busbar 10.

[0022] The shape of the core 20 in this embodiment will be described in detail below. Each core 20 has the same shape. Furthermore, each core 20 is arranged so that its positional relationship with each busbar 10 is the same. For example, each core 20 is arranged so that the core bottom portion 27 of each core 20, which will be described later, is located on the same side with respect to each busbar 10.

[0023] As shown in Figure 4, the core 20 has a core inner surface 20a which faces the core hole 200, and a core outer surface 20b which is opposite to the core inner surface 20a. Furthermore, as shown in Figure 9 and other figures described later, the core 20 has a core side surface 20c that connects the core inner surface 20a and the core outer surface 20b. In this embodiment, the core side surface 20c is a surface that is substantially parallel to the XZ plane and is a surface that is normal to the Y axis direction. The core 20 also has a shape that includes a first gap forming portion 21, a second gap forming portion 22, a first core lateral portion 23, a second core lateral portion 24, a first gap-side connecting portion 25, a second gap-side connecting portion 26, a core bottom portion 27, a first bottom-side connecting portion 28, and a second bottom-side connecting portion 29.

[0024] Specifically, the first gap-forming portion 21 and the second gap-forming portion 22 each include a portion extending in the X-axis direction. The first gap-forming portion 21 is a surface whose normal direction is the X-axis direction and has a first end face 211 facing in the X-axis direction. The second gap-forming portion 22 is a surface whose normal direction is the X-axis direction and faces in the X-axis direction, and has a second end face 221 that faces the first end face 211 in the X-axis direction. The first end face 211 and the second end face 221 are spaced apart. Furthermore, the size and position of the second end face 221 are adjusted so that when the first end face 211 is projected in the X-axis direction, the projected first end face 221 overlaps with (i.e., coincides with) the first end face 211.

[0025] Furthermore, a gap 201 is formed in the core 20 in the space between the first end face 211 and the second end face 221. In other words, the gap 201 is a space that is partitioned by the first end face 211 and the second end face 221. The gap 201 is in communication with the outside of the core 20 and the core hole 200.

[0026] The first core lateral portion 23 is connected to the first gap forming portion 21 via the first gap-side connecting portion 25 and extends in the Z-axis direction from the boundary with the first gap-side connecting portion 25. The second core lateral portion 24 is connected to the second gap forming portion 22 via the second gap-side connecting portion 26 and extends in the Z-axis direction from the boundary with the second gap-side connecting portion 26.

[0027] The first gap-side connecting portion 25 is positioned between the portion of the first gap-forming portion 21 opposite to the first end face 211 and the first core lateral portion 23, connecting the first gap-forming portion 21 and the first core lateral portion 23. The second gap-side connecting portion 26 is positioned between the portion of the second gap-forming portion 22 opposite to the second end face 221 and the second core lateral portion 24, connecting the second gap-forming portion 22 and the second core lateral portion 24. Furthermore, the first gap-side connecting portion 25 and the second gap-side connecting portion 26 are each given a rounded R-shape with curvature to reduce the magnetic resistance of the core 20.

[0028] The core bottom portion 27 has a portion that extends in the X-axis direction and is connected to the first core lateral portion 23 via the first bottom-side connecting portion 28 and to the second core lateral portion 24 via the second bottom-side connecting portion 29.

[0029] The first bottom-side connecting portion 28 is positioned between the first core lateral portion 23 and the core bottom portion 27, connecting the first core lateral portion 23 and the core bottom portion 27. The second bottom-side connecting portion 29 is positioned between the second core lateral portion 24 and the core bottom portion 27, connecting the second core lateral portion 24 and the core bottom portion 27. Furthermore, the first bottom-side connecting portion 28 and the second bottom-side connecting portion 29 are each given a rounded R-shape with curvature to reduce magnetic resistance.

[0030] In this embodiment, the core 20 is C-shaped. In this embodiment, the length between the inner surface 20a and the outer surface 20b of the core 20 is such that the core bottom 27 is longer than the first gap forming portion 21, the second gap forming portion 22, the first core side portion 23, the second core side portion 24, etc. In addition, in this embodiment, the portion of the first bottom-side connecting portion 28 and the second bottom-side connecting portion 29 that is on the core bottom 27 side is the same length as the core bottom 27. For this reason, in this embodiment, the core bottom 27, the first bottom-side connecting portion 28, and the portion of the second bottom-side connecting portion 29 that is on the core bottom 27 side are thicker portions. The busbar 10 is inserted through the core hole 200 of the core 20.

[0031] Herein, although not particularly limited, the core 20 of this embodiment is configured as follows, for example. That is, as shown in Figures 5 and 6, the core 20 has a core length YB1 in the Y-axis direction of 2 to 30 mm so as to be less susceptible to magnetic saturation. The core 20 contains the busbar 10, and the length XB1 in the X-axis direction of the opposing portions on the inner surface 20a of the first core lateral portion 23 and the second core lateral portion 24 is set to 12 to 32 mm so as to suppress the influence of magnetism and heat from the busbar 10. The core 20 has a length ZB1 in the Z-axis direction of the opposing portions on the inner surface 20a of the core bottom portion 27 and the first gap forming portion 21 and the second gap forming portion 22 is set to 2.5 to 20 mm so as to suppress the influence of magnetism and heat from the busbar 10. The core 20 has a length XB2 in the X-axis direction of the gap 201 of 5 to 20 mm based on the sensitivity and accuracy of the detection unit 30 which will be described later. The core 20 has a length XB3 in the X-axis direction at the first core lateral portion 23 and the second core lateral portion 24, which is 3 to 20 mm, in order to prevent magnetic saturation. The core bottom portion 27 has a length ZB2 in the Z-axis direction, which is 3 to 20 mm, in order to prevent magnetic saturation. The core 20 has a length ZB3 of 2 to 20 mm, which is the distance between the inner surface 20a of the core at the core bottom portion 27 and the outer surface 20b of the core at the first gap forming portion 21 and the second gap forming portion 22, in order to suppress misalignment of the detection portion 30 (described later) and the influence of adjacent phases. The inner diameter R1 of the first gap-side connecting portion 25, the second gap-side connecting portion 26, the first bottom-side connecting portion 28, and the second bottom-side connecting portion 29 is set to 10 mm or less in order to reduce magnetic resistance. The maximum value of the inner diameter R1 is set based on half of the maximum height of the length ZB1. The outer diameter R2 of the first gap-side connecting portion 25, the second gap-side connecting portion 26, the first bottom-side connecting portion 28, and the second bottom-side connecting portion 29 is set to 20 mm or less in order to reduce magnetic resistance. The maximum value of the outer diameter R2 is set based on lengths XB3, ZB2, and ZB3.

[0032] As shown in Figures 3 and 4, the detection unit 30 is positioned in the gap 201 of the core 20 and includes a detection element 31 and lead wires 32, etc. The detection element 31 is composed of a Hall element, a TMR element, a GMR element, an AMR element, etc., and may also include an IC, etc., as needed. The detection element 31 detects the strength of the magnetic field in the X-axis direction and outputs a signal corresponding to the detected magnetic field strength, for example, a voltage corresponding to the detected magnetic field strength, to the outside. TMR stands for Tunnel Magneto Resistive. GMR stands for Giant Magneto Resistive. AMR stands for Anisotropic Magneto Resistive. IC stands for Integrated Circuit. The detection unit 30 is positioned so that when the first end face 211 is projected in the X-axis direction, the detection element 31 overlaps with the projected first end face 211. The detection unit 30 is positioned such that when the second end face 221 is projected in the X-width direction, the detection element 31 overlaps with the projected second end face 221.

[0033] The lead wire 32 is plate-shaped, with one end connected to the detection element 31 and the other end connected to a land (not shown) on the substrate 40. Specifically, as shown in Figure 7, the other end of the lead wire 32 that connects to the substrate 40 is bent to form a bent portion 32a, and the bent portion 32a is connected to a land (not shown) on the substrate 40 via solder (not shown). In this embodiment, the bent portion 32a is bent in two places. Note that in Figures 3 and 4, the bent portion 32a is omitted for simplicity. In addition, there are multiple lead wires 32, some of which are bent to one side in the X-axis direction, and the remaining lead wires 32 are bent to the other side in the X-axis direction.

[0034] Herein, although not particularly limited, the detection unit 30 of this embodiment is configured as follows, for example. Specifically, the detection unit 30 has a vertical angle θ1 between the detection element 31 and the substrate 40 that is 80 to 100° in order to improve detection accuracy. The detection unit 30 has an angle θ2 between the detection element 31 and the bent portion 32a of the lead wire 32 that is 80 to 100° in order to improve ease of movement during solder reflow, improve the quality of solder fillets, and improve the adjustment of solder joint length. The detection unit 30 has a height ZC1 from the substrate 40 to the detection element 31 (i.e., the length of the lead wire 32 in the Z-axis direction) ZC1 that is 1.5 to 23.5 mm in order to improve vibration resistance while improving detection accuracy. The detection unit 30 has a length ZC2 in the Z-axis direction of the bent portion 32a that is 0.5 to 12 mm in order to improve vibration resistance while improving the adjustment of solder joint length. The detection unit 30 has an angle θ3 of the bent portion 32a with respect to the direction normal to the surface direction of the substrate 40 (i.e., the Z-axis direction) of 10 to 40°. The detection unit 30 has a diameter R3 of the bent portion 32a of 0.05 mm or more to improve vibration resistance. The detection unit 30 has a length XC1 in the X-axis direction of the bent portion 32a of the lead wire 32 of 1.5 to 10 mm to improve ease of movement during reflow, improve the quality of solder fillets, and improve adjustment of solder joint length.

[0035] The substrate 40 is made up of a printed circuit board or the like, which is shaped like a rectangular plane with one direction as its longitudinal direction. As described above, the detection unit 30 is mounted on the substrate 40 so as to be connected to lands (not shown). In addition, as shown in Figures 8 and 10, the substrate 40 has substrate recesses 402 and substrate holes 404 formed therein.

[0036] Specifically, if the side surface of the substrate 40 that is parallel to the XZ plane and whose normal direction is the Y axis direction is defined as the substrate side surface 400, then the substrate recess 402 is composed of a recess formed in the substrate side surface 400. In this embodiment, the substrate recess 402 is in the shape of an elongated arc. However, the shape of the substrate recess 402 is not limited to an elongated arc, and may be, for example, a polygon, an arc, an elliptical arc, etc. Furthermore, although Figure 8 shows an example in which there are three substrate recesses 402, the number of substrate recesses 402 can be changed as appropriate, and may be one or four or more.

[0037] The substrate holes 404 are through holes that penetrate the substrate 40 in the Z-axis direction. Although not indicated by reference numerals in Figure 8, the portion that coincides with the protrusion 521, which will be described later, is the substrate hole 404. In this embodiment, the shape of the substrate hole 404 is cylindrical, but it may also be polygonal prism or elliptical prism. In this embodiment, there are five substrate holes 404, and as will be described later, they are formed in the case 50 in the Z-axis direction at positions that overlap with the gap 201 of each core 20 and at positions that overlap with the partition portion 501. In this embodiment, an example in which there are five substrate holes 404 is described, but the number of substrate holes 404 is not limited to this, and there may be one or six or more.

[0038] The case 50 is constructed by injection molding a thermoplastic resin such as polybutylene terephthalate, and the busbar 10, core 20, detection unit 30, substrate 40, terminal 70, collar 80, etc. are assembled to it. As shown in Figures 1 to 3, the case 50 is formed so that its length in the X-axis direction is the longitudinal direction, since the busbar 10 and core 20, etc. are arranged in the X-axis direction.

[0039] Each core 20 is insert-molded and fixed into the case 50. In other words, the core 20 and the case 50 are integrally molded. Specifically, each core 20 is insert-molded into the case 50 such that the core hole 200 extends in the Y-axis direction. The relationship between the core 20 and the case 50 in this embodiment will be described below with reference to Figure 4.

[0040] The core 20 is fixed to the case 50 such that portions of the core 20 on the side opposite to the core bottom 27 side in the first gap forming portion 21 and the second gap forming portion 22, and portions of the outer core surface 20b in the first gap side connecting portion 25 and the second gap side connecting portion 26 that are opposite to the core bottom 27 side are exposed from the case 50.

[0041] More specifically, the core 20 of the present embodiment intersects (i.e., passes through) a virtual line K extending in the X-axis direction through the centers in the Z-axis direction of the first end surface 211 and the second end surface 221. That is, the first gap side connecting portion 25 and the second gap side connecting portion 26 are arranged. In other words, the first gap side connecting portion 25 and the second gap side connecting portion 26 are configured to have a portion located on the side opposite to the core bottom 27 side with respect to the virtual line K and a portion located on the core bottom 27 side. And the core 20 of the present embodiment is fixed to the case 50 such that a portion of the core 20 located on the side opposite to the core bottom 27 side with respect to the virtual line K is exposed from the case 50.

[0042] Also, on the core inner surface 20a side, the case 50 is arranged along the core inner surface 20a so as not to embed the core hole 200, and is arranged such that a cavity 51 surrounded by the case 50 is formed inside. And the bus bar 10 is inserted through this cavity 51. Note that the portion of the case 50 arranged on the core inner surface 20a side is provided to ensure insulation from the bus bar 10.

[0043] Furthermore, in the present embodiment, in the portion of the case 50 arranged in the gap 201, a recess 50a recessed toward the cavity 51 side is formed in the portion opposite to the cavity 51 side. This recess 50a is formed to secure a space when arranging the detection portion 30 in the gap 201.

[0044] Also, in the present embodiment, as shown in FIG. 9, the pair of core side surfaces 20c of the core 20 are provided such that one core side surface 20c is covered by the case 50 and the other core side surface 20c is exposed from the case 50. Note that FIG. 9 is a plan view showing the case 50 and the core 20 viewed from the Z-axis direction, and the substrate 40 is omitted.

[0045] As shown in FIGS. 3 and 9, the case 50 has a shape that covers and holds the core 20 as described above, and further has partition portions 501, a substrate accommodation chamber 510, convex portions 521, pedestals 522, a connector portion 530, and the like.

[0046] The partition portion 501 is a portion disposed between adjacent cores 20 in the X-axis direction.

[0047] The substrate accommodation chamber 510 is a space for accommodating the substrate 40, and is provided on the gap 201 side of the core 20. The substrate 40 is provided in the substrate accommodation chamber 510 such that the detection element 31 of the detection unit 30 mounted on the substrate 40 is located in the gap 201 of the core 20. Specifically, the substrate 40 is fixed to the case 50 by the convex portions 521 and the pedestals 522. The detection element 31 is partially disposed in a recess 50a formed in the case 50.

[0048] As shown in FIGS. 9 and 10, the convex portions 521 are provided so as to protrude toward the substrate accommodation chamber 510 at positions facing the substrate holes 404 of the substrate 40. In the present embodiment, the convex portions 521 are provided in portions of the case 50 disposed between the gaps 201 of the respective cores 20 and in the partition portions 501. The pedestals 522 are provided so as to protrude toward the substrate accommodation chamber 510 in the vicinity of the convex portions 521. That is, in the present embodiment, the pedestals 522 are formed in portions of the case 50 disposed between the gaps 201 of the respective cores 20 and in the partition portions 501. The convex portions 521 and the pedestals 522 are made of the same material as the portion covering the core 20 and are formed simultaneously when manufacturing the case 50 in which the core 20 is insert-molded. Further, the convex portions 521 and the pedestals 522 are provided such that the convex portions 521 have a longer length in the Z-axis direction. The case 50 in FIG. 10 is a cross-sectional view taken along the X-X line in FIG. 9.

[0049] The protrusion 521 is then inserted into the substrate hole 404 and fixed to the substrate 40 by heat crimping or the like, as shown in Figure 10. In this embodiment, the protrusion 521 has an insertion portion 521a and a flange portion 521b formed at the tip of the insertion portion 521a. The insertion portion 521a is inserted into the substrate hole 404, and the flange portion 521b is in contact with the surface of the substrate 40 opposite to the substrate housing chamber 510 side. The base 522 also abuts against the surface of the substrate 40 on the substrate housing chamber 510 side and holds the substrate 40.

[0050] Furthermore, in this embodiment, the protrusions 521 and bases 522 are formed in a staggered pattern. Specifically, in the X-axis direction, the protrusions 521 and bases 522 are alternately arranged between the gaps 201 of each core 20 and the partition 501. More specifically, in this embodiment, the protrusions 521 and bases 522 arranged between the gaps 201 of each core 20 are located on one side in the Y-axis direction (i.e., the lower side of the paper in Figure 9), while the protrusions 521 and bases 522 formed on the partition 501 are located on the other side in the Y-axis direction (i.e., the upper side of the paper in Figure 9). In this embodiment, by arranging the protrusions 521 and bases 522 in a staggered pattern in this way, the substrate 40 is stably held in the case 50.

[0051] Furthermore, although not specifically shown in the figures, the case 50 has a case-side recess formed at a position opposite the substrate recess 402 in the Z-axis direction. This case-side recess communicates with the substrate 40 in the Z-axis direction, and the substrate 40 and the case 50 are positioned by fitting jigs such as pins into the substrate recess 402 and the case-side recess. This suppresses misalignment between the substrate 40 and the case 50, and also suppresses misalignment between the detection unit 30, the core 20 and the busbar 10.

[0052] Here, the substrate 40 and case 50 (i.e., the detection unit 30) of this embodiment are assembled, for example, as follows. That is, as shown in Figure 6, the detection element 31 is mounted at a position of 0 to ±15 mm from reference C1 in the Y-axis direction, with reference C1 being the center of the gap 201 in the Y-axis direction. The detection element 31 is also mounted at a position of 0 to ±9 mm from reference C2 in the X-axis direction, with reference C2 being the center of the gap 201 in the X-axis direction. Figure 6 shows the state in which the detection element 31 coincides with reference C1 and reference C2. Furthermore, as shown in Figure 5, the detection element 31 is positioned at a position of 0 to 22 mm from reference surface C3, with reference surface C3 being the boundary between the first end face 211 and the inner surface 20a of the core at the second end face 221, and the direction toward the outer surface 20b of the core at the first end face 211 and the second end face 221 being positive.

[0053] As shown in Figures 2 and 3, the terminals 70 are insert-molded into the case 50 and fixed to the case 50. Specifically, the terminals 70 are plate-shaped with their longitudinal direction in one direction (i.e., the Z-axis direction), and multiple terminals are fixed to the case 50 at one end in the X-axis direction of the case 50, penetrating the case 50 in the Z-axis direction. One end of each terminal 70 protruding towards the substrate housing chamber 510 is inserted into a through-hole electrode 41 formed in the substrate 40 and electrically connected to the substrate 40 by soldering or the like. The other end of the terminal 70 protruding away from the substrate housing chamber 510 is connected to an external circuit or the like (not shown).

[0054] The connector portion 530 is located on the side of the case 50 opposite to the substrate housing chamber 510, and is the portion where the other end of the terminal 70 is exposed. In other words, the connector portion 530 is configured such that an opening is formed and the other end of the terminal 70 protrudes into this opening. Here, although not particularly limited, the length XD1 of the connector portion 530 in the X-axis direction is set to approximately 0.5 to 4 mm, for example, because if it is too thick, it may bulge and cause poor mating with the external circuit.

[0055] As shown in Figures 1 and 2, the collar 80 is formed in an annular shape from metal or the like, and in this embodiment, it is positioned at both ends of the case 50 in the X-axis direction. The case 50 (i.e., the current sensor) is connected to an external circuit (i.e., an inverter circuit) by inserting a shaft or the like (not shown) into the collar 80. As described above, the case 50 is provided with a collar for a busbar mounting section (not shown), and each busbar 10 is fixed to the case 50 by assembling a busbar mounting section (not shown) on which each busbar 10 is mounted into the collar for the busbar mounting section.

[0056] The current sensor of this embodiment is configured as described above. Next, current detection using the current sensor of this embodiment will be explained.

[0057] When current flows from the inverter to the busbar 10, a circumferential magnetic field is generated centered on the longitudinal axis (i.e., the Y-axis) of the busbar 10. The generated magnetic field then passes through the gap 201 as magnetic field lines pass through each core 20. In other words, the magnetic field lines pass through the detection element 31. The detection element 31 then outputs a detection signal corresponding to the magnetic field in the X-axis direction to an external circuit (not shown) via lead wires 32, a substrate 40, and a terminal 70. In this embodiment, the current flowing through the busbar 10 is detected in this way.

[0058] Furthermore, in this embodiment, the core 20 is exposed from the case 50 at the portion of the first gap forming portion 21 and the second gap forming portion 22 opposite to the core bottom portion 27, and at the portion of the outer surface 20b of the core opposite to the core bottom portion 27 at the first gap side connecting portion 25 and the second gap side connecting portion 26. As a result, stress due to the expansion and contraction of the case 50 is less likely to be applied, and deformation of the core 20 can be suppressed. Consequently, a decrease in detection accuracy is suppressed.

[0059] In this embodiment described above, the core 20 has the portions of the first gap forming portion 21 and the second gap forming portion 22 that are opposite to the core bottom portion 27, and the portions of the core outer surface 20b of the first gap side connecting portion 25 and the second gap side connecting portion 26 that are opposite to the core bottom portion 27 exposed from the case 50. As a result, stress due to the expansion and contraction of the case 50 is less likely to be applied, and deformation of the core 20 can be suppressed. In particular, in this embodiment, the core outer surface 20b of the first gap side connecting portion 25 and the second gap side connecting portion 26, which are R-shaped portions that are easily deformed and whose deformation easily changes the spacing of the gap 201, is exposed from the case 50. As a result, compared to the case where only the first gap forming portion 21 and the second gap forming portion 22 are exposed from the case 50, a further decrease in detection accuracy can be suppressed.

[0060] (1) In this embodiment, the detection unit 30 is located in the gap 201. Therefore, it is easier to detect the magnetic field passing through the core 20, and the detection accuracy can be improved.

[0061] (2) In this embodiment, the core 20 has a portion of its outer surface 20b at the first gap-side connecting portion 25 and the second gap-side connecting portion 26 that is exposed from the case 50. In this case, the portion of the outer surface 20b of the core at the first gap-side connecting portion 25 and the second gap-side connecting portion 26 that is exposed from the case 50 can be changed, and the entire outer surface 20b of the core can be exposed from the case 50. With such a configuration, deformation of the core 20 due to stress caused by the expansion and contraction of the case 50 is further suppressed, and detection accuracy can be further improved.

[0062] (3) In this embodiment, the case 50 has a protrusion 521 and a base 522 formed thereon, and the substrate 40 is held by the protrusion 521 and the base 522. The protrusion 521 and the base 522 are made of the same material as the part of the case 50 that covers the core 20. Therefore, compared to the case in which the protrusion 521 and the base 522 are made of separate materials, the case 50 with the protrusion 521 and the base 522 can be manufactured in a single molding process, simplifying the manufacturing process. Also, since they can be formed with the same mold, the crossover variation between the core 20 and the substrate 40 (i.e., the protrusion 521 and the base 522) can be reduced, and the decrease in detection accuracy can be suppressed.

[0063] (4) In this embodiment, the protrusion 521 and the base 522 are arranged alternately in the X-axis direction, with portions formed on one side in the Y-axis direction and portions formed on the other side in the Y-axis direction. This allows the substrate 40 to be held stably.

[0064] (Modifications of the First Embodiment) Modifications of the first embodiment described above will now be explained. In the first embodiment described above, the protrusions 521 and the base 522 do not have to be formed in a staggered pattern, or only one of them may be formed in a staggered pattern. Also, the number of protrusions 521 and base 522 provided may differ.

[0065] (Summary of the First Embodiment) A summary of the first embodiment described above will now be explained. In the first embodiment, the protrusion 521 and the base 522 are made of the same material as the part of the case 50 that covers the core 20. Therefore, the current sensor of this embodiment can suppress a decrease in detection accuracy in this respect as well. Thus, the first embodiment can also be said to have the following features.

[0066] [First viewpoint] A current sensor comprising: a core (20) that collects a magnetic field based on a current generated by the flow of an electric current; a detection unit (30) that outputs a detection signal corresponding to the magnetic field; a substrate (40) on which the detection unit is provided; and a case (50) made of resin to which the core and the substrate are assembled, wherein the core and the case are integrally molded as a single piece; the substrate has a substrate hole (404) that penetrates in the thickness direction; the case has a protrusion (521) and a base (522) that project toward the substrate housing chamber (510), and the portion covering the core, the protrusion and the base are made of the same material; the substrate is placed in the substrate housing chamber; the protrusion is inserted through the substrate hole and the substrate is crimped and fixed in place; and the base is in contact with the substrate.

[0067] [Second viewpoint] The current sensor according to the first viewpoint, wherein the core is provided in multiple locations in one direction in the case, and if the one direction is designated as the first direction, and the direction intersecting the first direction and along the surface direction of the substrate is designated as the second direction, the convex portions are provided in multiple locations, and in the first direction, portions provided on one side of the second direction and portions provided on the other side of the second direction are alternately arranged.

[0068] [Third viewpoint] The current sensor according to the first or second viewpoint, wherein the core is provided in multiple locations in one direction in the case, and if the one direction is designated as the first direction, and the direction intersecting the first direction and along the surface direction of the substrate is designated as the second direction, the base is provided in multiple locations, and in the first direction, portions provided on one side of the second direction and portions provided on the other side of the second direction are alternately arranged.

[0069] (Second Embodiment) The second embodiment will now be described. This embodiment is a modification of the first embodiment in which the portion of the core 20 exposed from the case 50 is changed. Other aspects are the same as in the first embodiment, so the explanation will be omitted here.

[0070] In this embodiment, as shown in Figure 11, the core 20 has its outer surface 20b exposed from the case 50 at the first gap forming portion 21, the second gap forming portion 22, the first gap-side connecting portion 25, the second gap-side connecting portion 26, the first bottom-side connecting portion 28, and the second bottom-side connecting portion 29. In this embodiment, the entire outer surface 20b of the core 20 at the first gap forming portion 21, the second gap forming portion 22, the first gap-side connecting portion 25, the second gap-side connecting portion 26, the first bottom-side connecting portion 28, and the second bottom-side connecting portion 29 is exposed from the case 50. Note that Figure 11 is a cross-sectional view of the portion corresponding to Figure 4.

[0071] Furthermore, the outer surface 20b of the core is held by the case 50, with the first core lateral portion 23, the second core lateral portion 24, and the core bottom portion 27 being covered. In other words, only the linear first core lateral portion 23 and the second core lateral portion 24 extending in the Z-axis direction, and the linear core bottom portion 27 extending in the X-axis direction are held by the case 50 on the outer surface 20b of the core 20.

[0072] According to the embodiment described above, the core 20 has portions of the first gap forming portion 21 and the second gap forming portion 22 that are opposite to the core bottom portion 27, and portions of the first gap side connecting portion 25 and the second gap side connecting portion 26 that are opposite to the core bottom portion 27 that are exposed from the case 50. Therefore, the same effects as in the first embodiment can be obtained.

[0073] (1) In this embodiment, the entire outer surface 20b of the core 20 at the first gap forming portion 21, the second gap forming portion 22, the first gap-side connecting portion 25, the second gap-side connecting portion 26, the first bottom-side connecting portion 28, and the second bottom-side connecting portion 29 is exposed from the case 50. In other words, the outer surface 20b of the core 20 at the portion that is easily deformable and has an R shape is exposed from the case 50. Therefore, deformation of the core 20 due to stress caused by the expansion and contraction of the case 50 can be suppressed, and a decrease in detection accuracy can be suppressed.

[0074] (2) In this embodiment, the core outer surface 20b of the core 20 is held by the case 50 only by the linear first core lateral portion 23 and the second core lateral portion 24 extending in the Z-axis direction, and the linear core bottom portion 27 extending in the X-axis direction. In other words, the case 50 is not positioned on the R-shaped core outer surface 20b. Therefore, the generation of resin burrs on the core outer surface 20b during insert molding of the core 20 can be suppressed. Consequently, compared to the case 50 where resin burrs are generated, the peeling or detachment of resin burrs due to environmental stresses such as thermal stress and vibration stress can be suppressed, thereby improving reliability.

[0075] (Modification of the Second Embodiment) A modification of the second embodiment described above will now be explained. In the second embodiment described above, the core 20 was described in which the entire outer surface 20b of the core at the first gap forming portion 21, the second gap forming portion 22, the first gap-side connecting portion 25, the second gap-side connecting portion 26, the first bottom-side connecting portion 28, and the second bottom-side connecting portion 29 is exposed from the case 50. However, the core 20 may be arranged such that a part of the outer surface 20b of the core at the first gap-side connecting portion 25, the second gap-side connecting portion 26, the first bottom-side connecting portion 28, and the second bottom-side connecting portion 29 is exposed from the case 50. Also, as a modification of the structure shown in Figure 11, the outer surface 20b of the core at the first core lateral portion 23, the second core lateral portion 24, and the core bottom portion 27 may be exposed from the case 50.

[0076] Furthermore, in the second embodiment described above, as shown in Figure 12, the core 20 may have its outer surface 20b of the core bottom 27 exposed from the case 50, in addition to the outer surface 20b of the first gap forming portion 21, the second gap forming portion 22, the first gap-side connecting portion 25, the second gap-side connecting portion 26, the first bottom-side connecting portion 28, and the second bottom-side connecting portion 29. In other words, the outer surface 20b of the core may be covered and held by the case 50 only for the first core lateral portion 23 and the second core lateral portion 24. Moreover, as a modification of the structure shown in Figure 12, either the outer surface 20b of the first core lateral portion 23 or the second core lateral portion 24 may be exposed from the case 50.

[0077] Furthermore, in the second embodiment described above, the core outer surfaces 20b of the first gap-side connecting portion 25, the second gap-side connecting portion 26, the first bottom-side connecting portion 28, and the second bottom-side connecting portion 29, which are R-shaped, are exposed from the case 50, so that stress from the case 50 can be relieved in this portion. Therefore, for example, as shown in Figure 13, the core 20 may have the core outer surfaces 20b of the first gap-side connecting portion 25, the second gap-side connecting portion 26, the first bottom-side connecting portion 28, and the second bottom-side connecting portion 29 exposed from the case 50, while the core outer surfaces 20b of the first gap-forming portion 21, the second gap-forming portion 22, the first core lateral portion 23, the second core lateral portion 24, and the core bottom portion 27 may be covered by the case 50. Furthermore, as a modification of the structure shown in Figure 13, any of the core outer surfaces 20b of the first gap forming portion 21, the second gap forming portion 22, the first core lateral portion 23, the second core lateral portion 24, or the core bottom portion 27 may be exposed from the case 50. In other words, in the configurations shown in Figures 11 to 13, the portion exposed from the case 50 may be further modified as appropriate.

[0078] (Summary of the Second Embodiment) A summary of the second embodiment described above will now be explained. In the second embodiment, the first gap-side connecting portion 25, the second gap-side connecting portion 26, the first bottom-side connecting portion 28, and the second bottom-side connecting portion 29, which are R-shaped, are exposed from the case 50. Therefore, the current sensor of the second embodiment can suppress a decrease in detection accuracy in this respect as well. Thus, it can be said that the second embodiment has the following features.

[0079] [First Perspective] A current sensor comprising: a core (20) that collects a magnetic field based on the current generated by the flow of current; a detection unit (30) that outputs a detection signal corresponding to the magnetic field; and a case (50) made of resin to which the core and the detection unit are assembled, wherein the core and the case are integrally molded as a single piece, and the core is A core hole (200), a core inner surface (20a) that faces the core hole, a core outer surface (20b) that faces the core inner surface, a first gap forming portion (21) having a first end surface (211) and extending in a first direction, a second gap forming portion (22) having a second end surface (221) that faces the first end surface and forms a gap (201) between itself and the first end surface and extending in the first direction, a first core lateral portion (23) extending in a second direction intersecting the first direction, a second core lateral portion (24) extending in the second direction, and the portion of the first gap forming portion opposite to the first end surface and the first core A current sensor comprising: a first gap-side connecting portion (25) positioned between the lateral portion and having a curved, rounded shape; a second gap-side connecting portion (26) positioned between the portion of the second gap-forming portion opposite to the second end face and the second core lateral portion and having a curved, rounded shape; a core bottom portion (27) extending in the first direction; a first bottom-side connecting portion (28) positioned between the first core lateral portion and the core bottom portion and having a curved, rounded shape; and a second bottom-side connecting portion (29) positioned between the second core lateral portion and the core bottom portion, having a curved, rounded shape, wherein the first gap-side connecting portion, the second gap-side connecting portion, the first bottom-side connecting portion, and the second bottom-side connecting portion have portions exposed from the case.

[0080] (Third Embodiment) The third embodiment will now be described. This embodiment is a modification of the first embodiment in which the portion of the core 20 exposed from the case 50 is changed. Other aspects are the same as in the first embodiment, so the explanation will be omitted here.

[0081] In this embodiment, as shown in Figure 14, the core 20 has its outer surface 20b of the first gap forming portion 21, the second gap forming portion 22, the first core lateral portion 23, the second core lateral portion 24, the first gap-side connecting portion 25, and the second gap-side connecting portion 26 exposed from the case 50. The core 20 has its outer surface 20b of the core bottom portion 27, the first bottom-side connecting portion 28, and the second bottom-side connecting portion 29, on the portion on the core bottom portion 27 side, covered by the case 50. In other words, in this embodiment, the outer surface 20b of the core is held by the case 50 in the portion of the core 20 that is considered to be the thicker portion. Note that Figure 14 is a cross-sectional view of the portion corresponding to Figure 4.

[0082] According to the embodiment described above, the core 20 has portions of the first gap forming portion 21 and the second gap forming portion 22 that are opposite to the core bottom portion 27, and portions of the first gap side connecting portion 25 and the second gap side connecting portion 26 that are opposite to the core bottom portion 27 that are exposed from the case 50. Therefore, the same effects as in the first embodiment can be obtained.

[0083] (1) In this embodiment, the core outer surface 20b is covered by the case 50, with the core bottom 27 side of the core bottom 27, the first bottom-side connecting portion 28, and the second bottom-side connecting portion 29 being the thicker portion. In other words, the core 20 has the core outer surface 20b with high rigidity held by the case 50, while the core outer surface 20b with low rigidity is exposed from the case 50. Therefore, even if the case 50 expands or contracts, the core 20 is less likely to deform, and a decrease in detection accuracy and detection sensitivity can be suppressed.

[0084] (Modification of the Third Embodiment) A modification of the third embodiment described above will now be explained. In the third embodiment, the core outer surface 20b may be such that only the core bottom portion 27, which is the thicker portion, is covered by the case 50. In other words, the first bottom-side connecting portion 28 and the second bottom-side connecting portion 29 may be entirely exposed from the case 50.

[0085] (Fourth Embodiment) The fourth embodiment will now be described. This embodiment is a modification of the first embodiment in which the portion of the core 20 exposed from the case 50 is changed. Other aspects are the same as in the first embodiment, so the explanation will be omitted here.

[0086] In this embodiment, as shown in Figure 15, the core 20 of the current sensor has a core where the portion of the core outer surface 20b on the side of a pair of core sides 20c is covered by the case 50. The inner edge portion of the core 20b opposite to the pair of core sides 20c is exposed from the case 50. In this embodiment, the inner edges of the first gap forming portion 21, the second gap forming portion 22, the first core side portion 23, the second core side portion 24, the first gap-side connecting portion 25, the second gap-side connecting portion 26, the core bottom portion 27, the first bottom-side connecting portion 28, and the second bottom-side connecting portion 29 of the core outer surface 20b are exposed from the case 50. Therefore, in this embodiment as well, similar to the first embodiment described above, the portions of the first gap forming portion 21 and the second gap forming portion 22 opposite to the core bottom portion 27, and the portions of the core outer surface 20b of the first gap side connecting portion 25 and the second gap side connecting portion 26 opposite to the core bottom portion 27, have portions that are exposed from the case 50.

[0087] According to the embodiment described above, the core 20 has portions of the first gap forming portion 21 and the second gap forming portion 22 that are opposite to the core bottom portion 27, and portions of the first gap side connecting portion 25 and the second gap side connecting portion 26 that are opposite to the core bottom portion 27 that are exposed from the case 50. Therefore, the same effects as in the first embodiment can be obtained.

[0088] (1) As in this embodiment, the core 20 may be covered by the case 50 on the side 20c of the core. And because the core 20 may be covered by the case 50 on the side 20c of the core, the degree of design freedom can be improved.

[0089] (Modification of the Fourth Embodiment) A modification of the fourth embodiment described above will now be explained. In the fourth embodiment described above, the core outer surface 20b is shown in which the inner edges of each of the first gap forming portion 21, the second gap forming portion 22, the first core lateral portion 23, the second core lateral portion 24, the first gap-side connecting portion 25, the second gap-side connecting portion 26, the core bottom portion 27, the first bottom-side connecting portion 28, and the second bottom-side connecting portion 29 are exposed from the case 50. However, the core 20 only needs to have a portion exposed from the case 50 on the inner edge side of the core outer surface 20b. For example, the core 20 has a portion exposed from the case 50 on the inner edge side of the pair of core side surfaces 20c on the core outer surface 20b, so the entire core bottom portion 27 may be covered by the case 50, or the entire first core lateral portion 23 or the second core lateral portion 24 may be covered by the case 50.

[0090] (Summary of the Fourth Embodiment) A summary of the fourth embodiment described above will now be explained. In the fourth embodiment, the core 20 has a portion exposed from the case 50 on the inner edge side opposite to the pair of core side surfaces 20c of the outer surface 20b of the core. Therefore, in this respect as well, a decrease in detection accuracy can be suppressed. Accordingly, the fourth embodiment can be said to have the following features.

[0091] [First viewpoint] A current sensor comprising: a core (20) that collects a magnetic field based on a current generated by the flow of an electric current; a detection unit (30) that outputs a detection signal corresponding to the magnetic field; and a case (50) made of resin to which the core and the detection unit are assembled, wherein the core and the case are integrally molded as a single molded product, the core having a core hole (200), a core inner surface (20a) which is the surface facing the core hole, a core outer surface (20b) which is the surface opposite to the core inner surface, and a pair of core sides (20c) connecting the core inner surface and the core outer surface, the core outer surface having portions on the sides of the pair of core sides covered by the case, and portions on the inner edge side opposite to the pair of core sides exposed from the case.

[0092] [Second viewpoint] The core has a first gap-forming portion (21) having a first end face (211) and extending in a first direction, a second gap-forming portion (22) having a second end face (221) facing the first end face and forming a gap (201) between itself and the first end face and extending in the first direction, a first core lateral portion (23) extending in a second direction intersecting the first direction, a second core lateral portion (24) extending in the second direction, and a rounded shape with curvature arranged between the portion of the first gap-forming portion opposite to the first end face and the first core lateral portion. It has a first gap-side connecting portion (25), a second gap-side connecting portion (26) which is positioned between the portion of the second gap-forming portion opposite to the second end face and the second core side portion and has a curved, rounded shape, a core bottom portion (27) which extends in the first direction, a first bottom-side connecting portion (28) which is positioned between the first core side portion and the core bottom portion and has a curved, rounded shape, and a second bottom-side connecting portion (29) which is positioned between the second core side portion and the core bottom portion and has a curved, rounded shape. The current sensor according to the first view, wherein the first gap forming portion, the second gap forming portion, the first core side portion, the second core side portion, the first gap-side connecting portion, the second gap-side connecting portion, the core bottom portion, the first bottom-side connecting portion, and the second bottom-side connecting portion have portions on the inner edge side opposite to the pair of core side portions that are exposed from the case.

[0093] (Fifth Embodiment) The fifth embodiment will now be described. This embodiment is a modification of the arrangement of the core 20 compared to the first embodiment. Other aspects are the same as in the first embodiment, so the explanation will be omitted here.

[0094] As shown in Figure 16, the core 20 of this embodiment is a press-molded body constructed by laminating multiple plate materials in the direction normal to the core side surface 20c and pressing them along this normal direction. In other words, the core 20 is a press-molded body formed by pressing one side of a pair of core side surfaces 20c from the other side.

[0095] Furthermore, if the core 20 has a pair of core sides 20c, with the upstream side in the pressing direction being the upstream surface 201c and the downstream side in the pressing direction being the downstream surface 202c, then burrs are more likely to occur on the downstream surface 202c side than on the upstream surface 201c side. Therefore, the core 20 is marked with a marker 203c on one of its core sides 20c so that the upstream surface 201c, which is less prone to burrs, and the downstream surface 202c, which is more prone to burrs, can be identified. Note that the marker 203c may be formed on either of the pair of core sides 20c as long as it can identify the upstream surface 201c and the downstream surface 202c. That is, the marker may be placed on the upstream surface 201c, which is less prone to burrs, or on the downstream surface 202c, which is more prone to burrs. Also, the marker is not particularly limited as long as it is an identifiable mark, and may be formed by applying ink, or by making a recess, for example.

[0096] As shown in Figure 17, the core 20 is configured such that the upstream surface 201c of the core side surface 20c is covered by the case 50, and the downstream surface 202c is exposed from the case 50. In other words, the core 20 is configured such that the core side surface 20c, which is prone to burr formation, is separated from the case 50. In this embodiment as well, similar to the first embodiment, the core 20 has portions of the first gap forming portion 21 and the second gap forming portion 22 that are opposite to the core bottom portion 27, and portions of the core outer surface 20b of the first gap side connecting portion 25 and the second gap side connecting portion 26 that are opposite to the core bottom portion 27, which are exposed from the case 50.

[0097] According to the embodiment described above, the core 20 has portions of the first gap forming portion 21 and the second gap forming portion 22 that are opposite to the core bottom portion 27, and portions of the first gap side connecting portion 25 and the second gap side connecting portion 26 that are opposite to the core bottom portion 27 that are exposed from the case 50. Therefore, the same effects as in the first embodiment can be obtained.

[0098] (1) In this embodiment, the core 20 is a press-formed body pressed from one side of a pair of core sides 20c toward the other, and is positioned so that the downstream surface 202c is exposed from the case 50. Therefore, it is possible to suppress burrs of the core 20 from biting into the case 50, and to suppress the deformation of the core 20 or damage to the case 50 due to stress concentration starting points during expansion and contraction of the case 50. Thus, it is possible to suppress a decrease in detection accuracy.

[0099] (Modification of the Fifth Embodiment) A modification of the fifth embodiment described above will now be explained. In the fifth embodiment, the core 20 is arranged such that its upstream surface 201c is covered by the case 50, but the upstream surface 201c may also be exposed from the case 50. In addition, the outer surface 20b of the core may be completely covered by the case 50 or partially exposed.

[0100] (Summary of the Fifth Embodiment) A summary of the fifth embodiment described above will now be explained. In the fifth embodiment, the downstream surface 202c of the core side surface 20c is exposed from the case 50. Therefore, in the fifth embodiment, a decrease in detection accuracy can be suppressed in this respect as well. Thus, the fifth embodiment can be said to have the following features.

[0101] [First point of view] A current sensor comprising a core (20) that collects a magnetic field based on the current generated by the flow of current, a detection unit (30) that outputs a detection signal corresponding to the magnetic field, and a case (50) made of resin to which the core and the detection unit are assembled, wherein the core and the case are integrally molded as a single piece, The core has a core hole (200), a core inner surface (20a) that faces the core hole, a core outer surface (20b) that faces the opposite side of the core inner surface, and a pair of core sides (20c) connecting the core inner surface and the core outer surface. The core is a press-formed product formed by pressing multiple plate materials stacked in a direction normal to the core sides. In the pair of core sides, the core side on the upstream side in the pressing direction during pressing is designated as the upstream surface (201c), and the other core side is designated as the downstream surface (202c). A mark (203c) for distinguishing the upstream surface from the downstream surface is provided on one of the pair of core sides, and the downstream surface is exposed from the case.

[0102] (Sixth Embodiment) The sixth embodiment will now be described. This embodiment is characterized by the addition of ribs to the case 50 compared to the first embodiment. Other aspects are the same as the first embodiment, so the explanation will be omitted here.

[0103] As shown in Figures 18 and 19, the current sensor of this embodiment is provided with a partition portion 501 located between adjacent cores 20 in the case 50, and a rib portion 502 that protrudes in the Z-axis direction toward the substrate housing chamber 510. Specifically, the rib portion 502 is formed such that its tip in the Z-axis direction is located toward the substrate 40 side than the core outer surface 20b in the first gap forming portion 21 and second gap forming portion 22 of each core 20. In other words, the case 50 is provided with the rib portion 502 so as to substantially partition the area where each core 20 is provided. In this embodiment, the protrusion 521 and base 522 that were provided on the partition portion 501 in the first embodiment are not shown, but are provided on the tip of the rib portion 502 in the protruding direction.

[0104] According to the embodiment described above, the core 20 has portions of the first gap forming portion 21 and the second gap forming portion 22 that are opposite to the core bottom portion 27, and portions of the first gap side connecting portion 25 and the second gap side connecting portion 26 that are opposite to the core bottom portion 27 that are exposed from the case 50. Therefore, the same effects as in the first embodiment can be obtained.

[0105] (1) In this embodiment, rib portions 502 are provided between adjacent cores 20. This prevents conductive foreign matter from being caught between adjacent cores 20. Therefore, a decrease in detection accuracy can be prevented. In addition, the strength of the case 50 can be improved by providing the rib portions 502.

[0106] (2) In this embodiment, the rib portion 502 is formed such that its tip in the protruding direction is located on the substrate 40 side of the core 20. This prevents foreign matter from being further trapped between adjacent cores 20.

[0107] (3) In this embodiment, the protrusion 521 and the base 522 are formed at the tip of the rib portion 502. Therefore, compared to the first embodiment, the length in the Z-axis direction of the protrusion 521 and the base 522 can be shortened. Consequently, damage to the protrusion 521 and the base 522 can be suppressed.

[0108] (Modification of the sixth embodiment) A modification of the sixth embodiment described above will now be explained. In the sixth embodiment, the outer surface 20b of the core may be completely covered by the case 50 or may be partially exposed.

[0109] (Summary of the sixth embodiment) A summary of the sixth embodiment will now be described. In the sixth embodiment, there is a rib portion 502 between adjacent cores 20. Therefore, the current sensor of the sixth embodiment can suppress a decrease in detection accuracy in this respect as well. Thus, it can be said that the sixth embodiment has the following features.

[0110] [First viewpoint] A current sensor comprising: a core (20) that collects a magnetic field based on a current generated by the flow of an electric current; a detection unit (30) that outputs a detection signal corresponding to the magnetic field; and a case (50) made of resin to which the core and the detection unit are assembled, wherein the core and the case are integrally molded as a single molded product; the core is provided in multiple locations in one direction within the case; and the case is provided with rib portions (502) that protrude in a direction intersecting the one direction between adjacent cores in the one direction, so that adjacent cores in the one direction are partitioned and arranged.

[0111] [Second viewpoint] The current sensor according to the first viewpoint, having a substrate (40) on which the detection unit is arranged and which is assembled to the case, wherein the rib portion protrudes toward the substrate side, and the tip of the protruding portion is located toward the substrate side from the portion of the core that is closest to the substrate side.

[0112] (Seventh Embodiment) The seventh embodiment will now be described. This embodiment is a modification of the first embodiment in which the shape of the terminal 70 is changed. As other aspects are the same as in the first embodiment, the explanation will be omitted here.

[0113] In this embodiment, as shown in Figure 20, the current sensor terminal 70 is plate-shaped with the Z-axis direction as its longitudinal direction, and has a wide portion 71 whose width is increased in a direction intersecting the longitudinal direction. In this embodiment, the terminal 70 has a wide portion 71 whose length is increased in the X-axis direction. The wide portion 71 may also be configured to have an increased length in the Y-axis direction. Furthermore, a recess 72 is formed as a hole from the side surface of the wide portion 71 of the terminal 70. In this embodiment, the recess 72 is arc-shaped. However, the recess 72 is not limited to being arc-shaped, and may be polygonal or elliptical arc-shaped, for example. Also, although Figure 20 shows an example with two recesses 72, the number of recesses 72 can be changed as appropriate, and may be one or three or more. Furthermore, the wide portion 71 of the terminal 70 is covered by the case 50, and the resin constituting the case 50 is also placed in the recess 72. This prevents the terminal 70 from being pulled out of the case 50.

[0114] In this embodiment described above, the core 20 is exposed from the case 50 at the portion of the first gap forming portion 21 and the second gap forming portion 22 opposite to the core bottom portion 27, and at the portion of the first gap-side connecting portion 25 and the second gap-side connecting portion 26 opposite to the core bottom portion 27. Therefore, the same effects as in the first embodiment can be obtained.

[0115] (1) In this embodiment, the terminal 70 has a wide portion 71, and a recess 72 is formed in the wide portion 71. The wide portion 71 is covered by the case 50, and the resin that makes up the case 50 also fills the recess 72. Therefore, it is possible to prevent the terminal 70 from being pulled out of the case 50, and consequently, to prevent a decrease in detection accuracy.

[0116] (Modification of the 7th Embodiment) A modification of the 7th embodiment will now be described. In the 7th embodiment described above, an example was described in which a recess 72 as a hole is formed in the terminal 70. However, as shown in Figure 21, the terminal 70 may have a through hole 73 formed in the wide portion 71. The through hole 73 is, for example, cylindrical in shape, but may also be polygonal or elliptical in shape. Also, Figure 21 shows an example in which there is one through hole 73, but the number of through holes 73 can be changed as appropriate and may be two or more. Furthermore, the outer surface 20b of the core may be completely covered by the case 50 or may be partially exposed.

[0117] (Summary of the Seventh Embodiment) A summary of the seventh embodiment described above will now be explained. In the seventh embodiment, the terminal 70 is provided with a wide portion 71, and a hole is formed in the wide portion 71. Therefore, the current sensor of the seventh embodiment can suppress a decrease in detection accuracy in this respect as well. Accordingly, it can be said that the seventh embodiment also has the following features.

[0118] [First viewpoint] A current sensor comprising: a core (20) that collects a magnetic field based on a current generated by the flow of current; a detection unit (30) that outputs a detection signal corresponding to the magnetic field; a substrate (40) on which the detection unit is provided; a terminal (70) electrically connected to the substrate; and a case (50) made of resin on which the core, the substrate, and the terminal are assembled, wherein the terminal and the case are integrally molded as a single piece, the terminal is plate-shaped with one direction as its longitudinal direction, has a wide portion (71) whose length is extended in a direction intersecting the longitudinal direction, has holes (72, 73) formed in the wide portion, and the wide portion including the holes is covered by the case.

[0119] (Eighth Embodiment) The eighth embodiment will now be described. In this embodiment, an exposure hole is formed in the case 50 to expose the core 20, compared to the first embodiment. Other aspects are the same as in the first embodiment, so the explanation will be omitted here.

[0120] In this embodiment, as shown in Figure 22, the current sensor case 50 has an exposure hole 52 formed in the portion facing the core 20 to expose the core 20. In this embodiment, the exposure hole 52 is formed in the portion of the core bottom 27 facing the outer surface 20b of the core. The exposure hole 52 may be formed by positioning a mold support pin to support the core 20 when insert molding the core 20 into the case 50, or it may be formed after insert molding.

[0121] According to the embodiment described above, the core 20 has portions of the first gap forming portion 21 and the second gap forming portion 22 that are opposite to the core bottom portion 27, and portions of the first gap side connecting portion 25 and the second gap side connecting portion 26 that are opposite to the core bottom portion 27 that are exposed from the case 50. Therefore, the same effects as in the first embodiment can be obtained.

[0122] (1) In this embodiment, the case 50 has an exposure hole 52 that exposes the core 20. Therefore, stress caused by the expansion and contraction of the case 50 can be relieved by the exposure hole 52, and deformation of the core 20 can be suppressed. Thus, a decrease in detection accuracy can be suppressed.

[0123] (Modification of the Eighth Embodiment) A modification of the eighth embodiment described above will now be explained. In the eighth embodiment, the location where the exposure holes 52 are formed can be changed as appropriate, and the number of exposure holes 52 can also be changed as appropriate. For example, as shown in Figure 23, four exposure holes 52 may be formed in the part of the case 50 facing the core side surface 20c to expose the core 20. Alternatively, the exposure holes 52 may be formed in the core bottom 27 and the part of the case 50 facing the core side surface 20c, respectively. Furthermore, in the eighth embodiment, the outer surface 20b of the core may be completely covered by the case 50, or it may be partially exposed, except for the part exposed by the exposure holes 52.

[0124] (Ninth Embodiment) The ninth embodiment will now be described. This embodiment is characterized by the addition of a projection to the case 50 compared to the eighth embodiment. Other aspects are the same as those of the eighth embodiment, so their explanation will be omitted here.

[0125] In this embodiment, as shown in Figure 24, the case 50 has a projection 53 that surrounds the exposed hole 52 and protrudes in the direction normal to the surface direction of the portion where the exposed hole 52 is formed. In this embodiment, the projection 53 is formed in a cylindrical shape, but it may also be polygonal or the like. Note that Figure 24 corresponds to a cross-section along the line XXIV-XXIV in Figure 23.

[0126] According to the embodiment described above, the core 20 has portions of the first gap forming portion 21 and the second gap forming portion 22 that are opposite to the core bottom portion 27, and portions of the first gap side connecting portion 25 and the second gap side connecting portion 26 that are opposite to the core bottom portion 27 that are exposed from the case 50. Therefore, the same effects as in the first embodiment can be obtained.

[0127] (1) In this embodiment, the case 50 has a projection 53 formed so as to surround the exposed hole 52. This makes it possible to increase the insulation distance (i.e., creepage distance) from the busbar 10 to the core 20 through the exposed hole 52. Therefore, the occurrence of creepage discharge can be suppressed, and a decrease in detection accuracy can be suppressed.

[0128] (Modification of the Ninth Embodiment) A modification of the ninth embodiment described above will now be explained. In the ninth embodiment, the projection 53 and the exposed hole 52 may be formed such that a stepped portion 53a is configured on the inner surface, as shown in Figure 25. This further increases the insulation distance from the busbar 10 to the core 20 through the exposed hole 52, and further suppresses the occurrence of surface discharge.

[0129] (Summary of the Eighth and Ninth Embodiments) A summary of the eighth and ninth embodiments described above will now be explained. In the eighth and ninth embodiments, an exposed hole 52 is formed in the case 50. Therefore, the current sensor of the eighth and ninth embodiments can suppress a decrease in detection accuracy in this respect as well. Thus, it can be said that the eighth and ninth embodiments also have the following features.

[0130] [First viewpoint] A current sensor comprising: a core (20) that collects a magnetic field based on a current generated by the flow of current; a detection unit (30) that outputs a detection signal corresponding to the magnetic field; and a case (50) made of resin to which the core and the detection unit are assembled, wherein the core and the case are integrally molded as a single molded product, and the case has an exposure hole (52) formed in the portion facing the core to expose the core.

[0131] [Second viewpoint] The current sensor according to the first viewpoint, wherein the case has a projection (53) formed around the exposed hole, projecting in the direction normal to the surface direction of the portion of the case in which the exposed hole is formed.

[0132] [Third viewpoint] The current sensor according to the second viewpoint, wherein the projection and the exposed hole are formed such that a stepped portion (53a) is configured on their inner surface.

[0133] (Tenth Embodiment) The tenth embodiment will now be described. This embodiment is a modification of the first embodiment in which the shape of the cavity 51 is changed. As other aspects are the same as in the first embodiment, the explanation will be omitted here.

[0134] In this embodiment, as shown in Figure 26, the current sensor case 50 is positioned so as to cover the inner surface 20a of the core, and a recessed portion 560 is formed in the portion that constitutes the cavity 51. As a result, the cavity 51 in this embodiment is wider than in the case where the recessed portion 560 is not formed. In this embodiment, the recessed portion 560 is formed in the portion of the case 50 that covers the inner surface 20a of the core, specifically in the portion that covers the first gap-side connecting portion 25 and the second gap-side connecting portion 26.

[0135] According to the embodiment described above, the core 20 has portions of the first gap forming portion 21 and the second gap forming portion 22 that are opposite to the core bottom portion 27, and portions of the first gap side connecting portion 25 and the second gap side connecting portion 26 that are opposite to the core bottom portion 27 that are exposed from the case 50. Therefore, the same effects as in the first embodiment can be obtained.

[0136] (1) In this embodiment, the case 50 has a recessed portion 560 formed in the part that constitutes the cavity 51, and the cavity 51 is widened. In other words, the air layer contained around the busbar 10 is increased. Furthermore, the air layer has higher thermal insulation properties than the resin material that constitutes the case 50. For this reason, compared to the case in which the recessed portion 560 is not formed, the core 20 can be made less susceptible to the heat of the busbar 10 through which the current flows, and a decrease in detection accuracy can be suppressed.

[0137] (2) When insert molding the core 20, the resin thickness tends to be thicker in the parts that cover the first gap-side connecting portion 25 and the second gap-side connecting portion 26, which have an R shape. For this reason, in this embodiment, the recessed portion 560 is formed in the part of the case 50 that covers the inner surface 20a of the core, specifically in the part that covers the first gap-side connecting portion 25 and the second gap-side connecting portion 26. As a result, the resin thickness in the part of the case 50 that covers the inner surface 20a of the core can be made uniform, and the formation of voids in the case 50 can be suppressed.

[0138] (3) In this embodiment, the recessed portion 560 is formed on the part of the case 50 that covers the first gap-side connecting portion 25 and the second gap-side connecting portion 26. Therefore, compared to the case in which the recessed portion 560 is formed on the part that closes the gap 201 (i.e., the part that faces the gap 201 in the Z-axis direction), it is easier to ensure a sufficient depth of the recess 50a. Thus, it is possible to suppress the detection element 31 from coming into contact with the case 50.

[0139] (Modification of the Tenth Embodiment) A modification of the Tenth Embodiment will now be described. In the Tenth Embodiment, the recessed portion 560 may be formed in the portion of the case 50 that covers the inner surface 20a of the core, specifically in the portion that covers the first bottom-side connecting portion 28 and the second bottom-side connecting portion 29. Furthermore, the recessed portion 560 may be formed in the portion of the case 50 that covers the inner surface 20a of the core, specifically in the portion that covers the first gap-side connecting portion 25, the second gap-side connecting portion 26, the first bottom-side connecting portion 28, and the second bottom-side connecting portion 29. The outer surface 20b of the core may be completely covered by the case 50 or partially exposed.

[0140] (Summary of the 10th Embodiment) A summary of the 10th embodiment described above will now be explained. In the 10th embodiment, a recess 560 is formed in the portion of the case 50 that covers the inner surface 20a of the core. Therefore, the current sensor of the 10th embodiment can suppress a decrease in detection accuracy in this respect as well. Thus, the 10th embodiment can be said to have the following features.

[0141] [First viewpoint] A current sensor comprising: a core (20) that collects a magnetic field based on a current generated by the flow of current; a detection unit (30) that outputs a detection signal corresponding to the magnetic field; and a case (50) made of resin to which the core and the detection unit are assembled, wherein the core and the case are integrally molded as a single molded product; the core has a core hole (200), a core inner surface (20a) which is the surface facing the core hole, and a core outer surface (20b) which is the surface opposite to the core inner surface; the case is formed to have a cavity (51) surrounded by a portion that covers the core inner surface, and a recess (560) is formed in the portion of the case that covers the core inner surface.

[0142] [Second viewpoint] The core has a first gap-forming portion (21) having a first end face (211) and extending in a first direction, a second gap-forming portion (22) having a second end face (221) facing the first end face and forming a gap (201) between itself and the first end face and extending in the first direction, a first core lateral portion (23) extending in a second direction intersecting the first direction, a second core lateral portion (24) extending in the second direction, and a rounded shape with curvature arranged between the portion of the first gap-forming portion opposite to the first end face and the first core lateral portion. The current sensor according to the first view, comprising: a first gap-side connecting portion (25); a second gap-side connecting portion (26) having a curved, rounded shape and positioned between the portion of the second gap-forming portion opposite to the second end face and the second core side portion; a core bottom portion (27) extending in the first direction; a first bottom-side connecting portion (28) having a curved, rounded shape and positioned between the first core side portion and the core bottom portion; and a second bottom-side connecting portion (29) having a curved, rounded shape and positioned between the second core side portion and the core bottom portion, wherein the recessed portion is formed in the portion that covers the inner surface of the core of the first gap-side connecting portion and the second gap-side connecting portion.

[0143] (Eleventh Embodiment) The eleventh embodiment will now be described. This embodiment specifies the flow direction of the molten resin when forming the case 50, compared to the first embodiment. Other aspects are the same as in the first embodiment, so further explanation will be omitted here.

[0144] The core 20 is integrated with the case 50 by insert molding as described above. When insert molding the core 20 into the case 50, the core 20 is placed in a mold, and molten resin is poured into the mold and solidified. At this time, the core 20 may deform due to the pressure applied from the molten resin.

[0145] Therefore, in this embodiment, as shown in Figure 27, when insert molding the core 20 into the case 50, the molten resin first reaches the core bottom 27, which is the thicker part of the core 20, and the direction along the normal direction to the surface direction of the thicker part becomes the flow direction of the molten resin. In this embodiment, the core bottom 27 is made thicker by having a length in the Z-axis direction between the inner surface 20a and the outer surface 20b of the core being longer than the length in the thickness direction of the first gap forming portion 21 and the second gap forming portion 22. Therefore, in this embodiment, the direction along the normal direction (i.e., the Z-axis direction) of the outer surface 20b of the core bottom 27 becomes the flow direction of the molten resin. For example, when insert molding the core 20 into the case 50, the gate in the mold, which is the entrance for the molten resin, is positioned to face the outer surface 20b of the core bottom 27. As a result, the molten resin flows along the core 20 after colliding with the core bottom 27, which is the thicker part, so deformation of the core 20 can be suppressed.

[0146] According to the embodiment described above, the core 20 has portions of the first gap forming portion 21 and the second gap forming portion 22 that are opposite to the core bottom portion 27, and portions of the first gap side connecting portion 25 and the second gap side connecting portion 26 that are opposite to the core bottom portion 27 that are exposed from the case 50. Therefore, the same effects as in the first embodiment can be obtained.

[0147] (1) In this embodiment, when insert molding the core 20 into the case 50, the molten resin first reaches the core bottom 27, which is the thicker part of the core 20, and the direction along the direction normal to the surface direction of the thicker part becomes the flow direction of the molten resin. As a result, the molten resin flows along the core 20 after colliding with the core bottom 27, which is the thicker part, so deformation of the core 20 can be suppressed.

[0148] (Modification of the 11th Embodiment) A modification of the 11th embodiment described above will now be explained. In the 11th embodiment, the outer surface 20b of the core may be completely covered by the case 50 or may be partially exposed. Also, in the first embodiment, an example was described in which the bottom portion 27 of the core is a thickened portion, but the thickened portion may be the first core side portion 23 or the second core side portion 24, etc.

[0149] (Summary of the 11th Embodiment) A summary of the 11th embodiment will now be described. In the 11th embodiment described above, when insert molding the core 20 into the case 50, the direction normal to the surface direction of the core bottom portion 27, which is the thickened portion, is made to coincide with the flow direction of the molten resin. Therefore, the 11th embodiment described above can manufacture a current sensor that suppresses a decrease in detection accuracy in this respect. Thus, the 11th embodiment described above can be said to have the following features.

[0150] [First viewpoint] A method for manufacturing a current sensor comprising: a core (20) that collects a magnetic field based on an electric current generated by the flow of an electric current; a detection unit (30) that outputs a detection signal corresponding to the magnetic field; and a case (50) made of resin to which the core and the detection unit are assembled, wherein the core and the case are integrally molded as an integral molded product, the method comprising: preparing the core; and forming the case by insert molding the core by pouring molten resin into a mold, wherein the core is prepared having a thickened portion in which the thickness is partially increased; and forming the case, the molten resin is poured into the mold such that the molten resin first reaches the thickened portion of the core, and the direction along the direction normal to the surface direction of the thickened portion is the flow direction of the molten resin.

[0151] (Twelfth Embodiment) The twelfth embodiment will now be described. This embodiment specifies the flow direction of the molten resin when forming the case 50, compared to the first embodiment. Other aspects are the same as in the first embodiment, so the explanation will be omitted here.

[0152] In this embodiment, when insert molding the core 20 into the case 50, as shown in Figure 28, the core 20 is positioned in the mold 600 such that the outer surface 20b of the core bottom 27 faces upward in the vertical direction, and the outer surfaces 20b of the core in the first gap forming portion 21 and the second gap forming portion 22 face downward in the vertical direction. Note that the core 20 in Figure 28 is a cross-sectional view along the line XXVIII-XXVIII in Figure 27. Also, in this embodiment, the core 20 is positioned in the mold 600 such that the core bottom 27 is the part that is furthest upward in the vertical direction.

[0153] The molten resin is then guided into the mold 600 such that, at the uppermost part of the core 20 in the vertical direction, the molten resin reaches the outer surface 20b of the core before the inner surface 20a of the core. For example, in this embodiment, the gate 601, which serves as the entrance for the molten resin in the mold 600, is located at the uppermost part of the core bottom 27 in the vertical direction, above the outer surface 20b of the core, and is positioned opposite the bottom 27 of the core. This ensures that at the uppermost part of the core 20 in the vertical direction, the molten resin reaches the outer surface 20b of the core before the inner surface 20a of the core, thereby suppressing displacement caused by core floating.

[0154] In other words, for example, as shown in Figure 29, if the flow direction of the molten resin is in the Y-axis direction, and the molten resin easily reaches the inner surface 20a side of the core from the outer surface 20b side of the core at the uppermost part of the core 20 in the vertical direction, the core 20 may float upward in the vertical direction due to the molten resin, potentially causing misalignment. Therefore, by using the method of this embodiment, the occurrence of core floating can be suppressed. Furthermore, in this embodiment, since the occurrence of core floating due to the flow direction of the molten resin is suppressed in this way, it is not necessary to provide support pins to hold down the core 20 in the mold 600. Accordingly, when constructing the case 50, the formation of holes in the part where the support pins that hold down the core 20 would be can be suppressed.

[0155] According to the embodiment described above, the core 20 has portions of the first gap forming portion 21 and the second gap forming portion 22 that are opposite to the core bottom portion 27, and portions of the first gap side connecting portion 25 and the second gap side connecting portion 26 that are opposite to the core bottom portion 27 that are exposed from the case 50. Therefore, the same effects as in the first embodiment can be obtained.

[0156] (1) In this embodiment, when insert molding the core 20 into the case 50, the molten resin is guided into the mold 600 such that the molten resin reaches the outer surface 20b of the core before the inner surface 20a of the core at the uppermost part of the core in the vertical direction. This suppresses the occurrence of core floating and positional displacement. Therefore, a current sensor with suppressed detection accuracy can be manufactured. In addition, in this embodiment, since the occurrence of core floating is suppressed by the flow direction of the molten resin, it is not necessary to provide support pins to hold the core 20 in the mold 600. Therefore, when constructing the case 50, it is possible to suppress the formation of holes that expose the core 20 in the area where the support pins would have been. Therefore, it is possible to suppress the occurrence of problems such as conductive foreign matter adhering to the holes that expose the core 20. In addition, since no holes that expose the core 20 are formed in the case 50, welds are not formed near these holes, and the occurrence of cracks can be suppressed. Furthermore, since the mold 600 does not require pins to support the core 20, the structure of the mold can be simplified.

[0157] (Modification of the 12th Embodiment) A modification of the 12th embodiment described above will now be explained. In the 12th embodiment, the outer surface 20b of the core may be completely covered by the case 50 or partially exposed. Also, the uppermost part of the core 20 in the vertical direction within the mold 600 does not have to be the core bottom 27.

[0158] (Summary of the 12th Embodiment) A summary of the 12th embodiment will now be described. In the 12th embodiment, when insert molding the core 20 into the case 50, the molten resin reaches the outer surface 20b of the core 20 before the inner surface 20a of the core, in the portion of the core 20 located on the top side in the vertical direction. Therefore, the 12th embodiment can manufacture a current sensor that suppresses a decrease in detection accuracy in this respect. Thus, the 12th embodiment can also be said to have the following features.

[0159] [First Perspective] A method for manufacturing a current sensor comprising: a core (20) that collects a magnetic field based on an electric current generated by the flow of an electric current; a detection unit (30) that outputs a detection signal corresponding to the magnetic field; and a case (50) made of resin to which the core and the detection unit are assembled, wherein the core and the case are integrally molded as an integral product, the method for manufacturing a current sensor comprising: preparing the core; pouring molten resin into a mold (600) to form the case in which the core is insert-molded, wherein the preparation of the core includes a core hole (200), a core inner surface (20a) that is the surface on the core hole side, and a core outer surface (20b) that is the surface opposite to the core inner surface, wherein the method for manufacturing a current sensor includes: positioning the core in the mold such that a part of the core outer surface is located at the highest point in the vertical direction; and pouring the molten resin into the mold such that the molten resin reaches the part of the core outer surface at the highest point in the vertical direction before the part of the core inner surface.

[0160] (Other Embodiments) While this disclosure has been described in accordance with embodiments, it is understood that this disclosure is not limited to such embodiments or structures. This disclosure also includes various modifications and variations within the scope of equivalents. In addition, various combinations and forms, as well as other combinations and forms that include only one, more, or fewer of those elements, fall within the scope and idea of ​​this disclosure.

[0161] For example, in each of the above embodiments, the placement of the collar 80 in the case 50 can be changed as appropriate. Also, in each of the above embodiments, the core 20 may have its first end face 211 and second end face 221 exposed from the case 50, as shown in Figure 30. In other words, the gap 201 may be configured without the case 50.

[0162] Furthermore, a current sensor can be constructed by appropriately combining each of the above embodiments.

[0163] [Disclosure of the Invention] The above disclosure can be understood, for example, from the following viewpoints. [First viewpoint] A current sensor comprising: a core (20) that collects a magnetic field based on the current generated by the flow of current; a detection unit (30) that outputs a detection signal corresponding to the magnetic field; and a case (50) made of resin to which the core and the detection unit are assembled, wherein the core and the case are integrally molded as a single molded product, and the core is A core hole (200), a core inner surface (20a) that faces the core hole, a core outer surface (20b) that faces the core inner surface, a first gap forming portion (21) having a first end surface (211) and extending in a first direction, a second gap forming portion (22) having a second end surface (221) that faces the first end surface and forms a gap (201) between itself and the first end surface and extending in the first direction, a first core lateral portion (23) extending in a second direction intersecting the first direction, a second core lateral portion (24) extending in the second direction, and the portion of the first gap forming portion opposite to the first end surface and the first core A current sensor comprising: a first gap-side connecting portion (25) positioned between the lateral portion and having a curved, rounded shape; a second gap-side connecting portion (26) positioned between the portion of the second gap-forming portion opposite to the second end face and the second core lateral portion and having a curved, rounded shape; a core bottom portion (27) extending in the first direction; a first bottom-side connecting portion (28) positioned between the first core lateral portion and the core bottom portion and having a curved, rounded shape; and a second bottom-side connecting portion (29) positioned between the second core lateral portion and the core bottom portion, having a curved, rounded shape, wherein the portions of the first gap-forming portion and the second gap-forming portion opposite to the core bottom portion, and the portions of the outer surface of the core in the first gap-side connecting portion and the second gap-side connecting portion opposite to the core bottom portion are exposed from the case. [Second viewpoint] The detection unit is the current sensor described in the first viewpoint, which is positioned in the gap. [Third viewpoint]The current sensor according to the first or second viewpoint, wherein the entire outer surface of the core of the core is exposed from the case, including the portion that will become the first gap-side connecting portion and the portion that will become the second gap-side connecting portion. [Fourth viewpoint] The current sensor according to any one of the first to third viewpoints, wherein the outer surface of the core of the core is exposed from the case, including the portion that will become the first bottom-side connecting portion and the portion that will become the second bottom-side connecting portion. [Fifth viewpoint] The current sensor according to any one of the first to fourth viewpoints, wherein only the first core side portion, the second core side portion, and the core bottom portion of the outer surface of the core are held in the case. [Sixth viewpoint] The current sensor according to any one of the first to fourth viewpoints, wherein only the first core side portion and the second core side portion of the outer surface of the core are held in the case. [Seventh viewpoint] The core is a current sensor according to any one of the first to fourth viewpoints, wherein the core bottom, the first bottom-side connecting portion, and the second bottom-side connecting portion are thicker than the other portions, and the core outer surface is such that the thick portion is held in place by the case. [Eighth viewpoint] The core has a pair of core sides (20c) connecting the core inner surface and the core outer surface, and the core outer surface is such that each portion of the pair of core sides is covered by the case. [Ninth Aspect] The core has a pair of core sides (20c) connecting the inner surface of the core and the outer surface of the core, and is a press-formed product in which a plurality of plate materials are stacked in the direction normal to the core sides and pressed, wherein, of the pair of core sides, the core side on the upstream side in the pressing direction when pressed is designated as the upstream surface (201c) and the other core side as the downstream surface (202c), and a mark (203c) for distinguishing the upstream surface and the downstream surface is provided on one of the pair of core sides, and the downstream surface is exposed from the case, the current sensor according to the first or second aspect. [Tenth Aspect] The core is provided in a plurality in one direction in the case,The current sensor according to any one of the first to ninth views, wherein the case is provided with rib portions (502) protruding in a direction intersecting the one direction between adjacent cores in the one direction, and adjacent cores in the one direction are partitioned and arranged. [Eleventh Viewpoint] The current sensor according to any one of the first to tenth views, comprising a substrate (40) on which the detection unit is arranged and which is assembled to the case, wherein the substrate has a substrate hole (404) that penetrates in the thickness direction, the case has a protrusion (521) and a base (522) protruding toward the substrate housing chamber (510), the portion covering the core, the protrusion and the base are made of the same material, the substrate is placed in the substrate housing chamber, the protrusion is inserted through the substrate hole and the substrate is crimped and fixed, and the base is in contact with the substrate. [Twelfth Perspective] A current sensor according to any one of the first to eleventh views, comprising: a substrate (40) on which the detection unit is arranged and which is assembled to the case; and a terminal (70) connected to the substrate and having a portion integrated with the case, wherein the terminal is plate-shaped with one direction as its longitudinal direction and has a wide portion (71) whose length is extended in a direction intersecting the longitudinal direction, holes (72, 73) are formed in the wide portion, and the wide portion including the holes is covered by the case. [Thirteenth Perspective] A current sensor according to any one of the first to twelfth views, wherein the case has an exposure hole (52) formed in a portion facing the core that exposes the core. [Fourteenth Perspective] A current sensor according to the thirteenth view, wherein the case has a projection (53) formed around the exposure hole that protrudes in a direction normal to the surface direction of the portion of the case in which the exposure hole is formed. [15th viewpoint] The current sensor according to the 14th viewpoint, wherein the projection and the exposed hole are formed such that a stepped portion (53a) is formed on the inner surface. [16th viewpoint] The current sensor according to any one of the 1st to 15th viewpoints, wherein the case is formed such that a cavity (51) is formed surrounded by a portion that covers the inner surface of the core, and a recess (560) is formed in the portion of the case that covers the inner surface of the core. [17th viewpoint]The current sensor according to the 16th aspect, wherein the cavity is formed in a portion that covers the inner surface of the core of the first gap-side connecting portion and the second gap-side connecting portion. [18th aspect] A current sensor comprising: a core hole (200) through which a current passage (10) through which current flows is inserted, a core (20) that collects a magnetic field generated by the current flowing through the current passage; a detection unit (30) that outputs a detection signal corresponding to the magnetic field; and a case (50) made of resin into which the current passage, the core, and the detection unit are assembled, wherein the core and the case are integrally molded, and the core is The core has an inner core surface (20a) that faces the core hole, an outer core surface (20b) that faces the opposite side of the inner core surface, a first gap-forming portion (21) having a first end surface (211) and extending in a first direction, a second gap-forming portion (22) having a second end surface (221) that faces the first end surface and forms a gap (201) between itself and the first end surface and extending in the first direction, a first core lateral portion (23) extending in a second direction intersecting the first direction, a second core lateral portion (24) extending in the second direction, and the space between the portion of the first gap-forming portion opposite to the first end surface and the first core lateral portion. A current sensor comprising: a first gap-side connecting portion (25) positioned and having a curved, rounded shape; a second gap-side connecting portion (26) positioned between the portion of the second gap-forming portion opposite to the second end face and the second core side portion and having a curved, rounded shape; a core bottom portion (27) extending in the first direction; a first bottom-side connecting portion (28) positioned between the first core side portion and the core bottom portion and having a curved, rounded shape; and a second bottom-side connecting portion (29) positioned between the second core side portion and the core bottom portion and having a curved, rounded shape, wherein the portions of the first gap-forming portion and the second gap-forming portion opposite to the core bottom portion, and the portions of the outer surface of the core in the first gap-side connecting portion and the second gap-side connecting portion opposite to the core bottom portion are exposed from the case. [Perspective 19] A core (20) that collects the magnetic field based on the current generated by the flow of current, and a detection unit (30) that outputs a detection signal corresponding to the magnetic field,The core and the detection unit are assembled in a case (50) made of resin, the core and the case are integrally molded as a single piece, the core has a core hole (200), a core inner surface (20a) which is the surface facing the core hole, a core outer surface (20b) which is the surface opposite to the core inner surface, a first gap forming portion (21) having a first end surface (211) and extending in a first direction, a second gap forming portion (22) having a second end surface (221) facing the first end surface and forming a gap (201) between itself and the first end surface and extending in the first direction, a first core lateral portion (23) extending in a second direction intersecting the first direction, a second core lateral portion (24) extending in the second direction, and the portion of the first gap forming portion opposite to the first end surface and the first core It has a first gap-side connecting portion (25) positioned between the lateral portion and having a curved, rounded shape; a second gap-side connecting portion (26) positioned between the portion of the second gap-forming portion opposite to the second end face and the second core lateral portion and having a curved, rounded shape; a core bottom portion (27) extending in the first direction; a first bottom-side connecting portion (28) positioned between the first core lateral portion and the core bottom portion and having a curved, rounded shape; and a second bottom-side connecting portion (29) positioned between the second core lateral portion and the core bottom portion and having a curved, rounded shape. A method for manufacturing a current sensor, wherein the portions of the first gap forming portion and the second gap forming portion opposite to the core bottom, and the portions of the outer surface of the core opposite to the core bottom in the first gap side connecting portion and the second gap side connecting portion are exposed from the case, the method comprising: preparing the core; and forming the case by insert molding the core by pouring molten resin into a mold, wherein the core is prepared having a partially thickened wall portion, and the case is formed by pouring the molten resin into the mold such that the molten resin first reaches the walled portion of the core, and the direction along the direction normal to the surface direction of the walled portion is the flow direction of the molten resin. [20th viewpoint]The device comprises a core (20) that collects a magnetic field based on the current generated by the flow of current, a detection unit (30) that outputs a detection signal corresponding to the magnetic field, and a case (50) made of resin to which the core and the detection unit are assembled, wherein the core and the case are integrally molded as a single piece, the core has a core hole (200), a core inner surface (20a) which is the surface on the core hole side, a core outer surface (20b) which is the surface opposite to the core inner surface, a first gap forming portion (21) having a first end surface (211) and extending in a first direction, a second gap forming portion (22) having a second end surface (221) facing the first end surface and forming a gap (201) between itself and the first end surface and extending in the first direction, a first core lateral portion (23) extending in a second direction intersecting the first direction, a second core lateral portion (24) extending in the second direction, and the portion of the first gap forming portion opposite to the first end surface and the first core It has a first gap-side connecting portion (25) positioned between the lateral portion and having a curved, rounded shape; a second gap-side connecting portion (26) positioned between the portion of the second gap-forming portion opposite to the second end face and the second core lateral portion and having a curved, rounded shape; a core bottom portion (27) extending in the first direction; a first bottom-side connecting portion (28) positioned between the first core lateral portion and the core bottom portion and having a curved, rounded shape; and a second bottom-side connecting portion (29) positioned between the second core lateral portion and the core bottom portion and having a curved, rounded shape. A method for manufacturing a current sensor, wherein the portions of the first gap forming portion and the second gap forming portion opposite to the core bottom, and the portions of the outer surface of the core opposite to the core bottom in the first gap side connecting portion and the second gap side connecting portion are exposed from the case, comprising: preparing the core; and pouring molten resin into a mold (600) to form the case in which the core is insert-molded.A method for manufacturing a current sensor, comprising: arranging the core in the mold such that a portion of the outer surface of the core is located at the highest point in the vertical direction; and pouring the molten resin into the mold such that the molten resin reaches the outer surface portion of the core before the inner surface portion of the core at the highest point in the vertical direction.

Claims

1. A current sensor comprising: a core (20) that collects a magnetic field based on the current generated by the flow of current; a detection unit (30) that outputs a detection signal corresponding to the magnetic field; and a case (50) made of resin to which the core and the detection unit are assembled, wherein the core and the case are integrally molded as a single piece, and the core is A core hole (200), a core inner surface (20a) that faces the core hole, a core outer surface (20b) that faces the core inner surface, a first gap forming portion (21) having a first end surface (211) and extending in a first direction, a second gap forming portion (22) having a second end surface (221) that faces the first end surface and forms a gap (201) between itself and the first end surface and extending in the first direction, a first core lateral portion (23) extending in a second direction intersecting the first direction, a second core lateral portion (24) extending in the second direction, and the portion of the first gap forming portion opposite to the first end surface and the first core A current sensor comprising: a first gap-side connecting portion (25) positioned between the lateral portion and having a curved, rounded shape; a second gap-side connecting portion (26) positioned between the portion of the second gap-forming portion opposite to the second end face and the second core lateral portion and having a curved, rounded shape; a core bottom portion (27) extending in the first direction; a first bottom-side connecting portion (28) positioned between the first core lateral portion and the core bottom portion and having a curved, rounded shape; and a second bottom-side connecting portion (29) positioned between the second core lateral portion and the core bottom portion, having a curved, rounded shape, wherein the portions of the first gap-forming portion and the second gap-forming portion opposite to the core bottom portion, and the portions of the outer surface of the core in the first gap-side connecting portion and the second gap-side connecting portion opposite to the core bottom portion are exposed from the case.

2. The current sensor according to claim 1, wherein the detection unit is positioned in the gap.

3. The current sensor according to claim 1, wherein the entire outer surface of the core of the core is exposed from the case, including the portion that will become the first gap-side connecting portion and the portion that will become the second gap-side connecting portion.

4. The current sensor according to claim 1, wherein the outer surface of the core has portions that become the first bottom-side connecting portion and the second bottom-side connecting portion that are exposed from the case.

5. The current sensor according to claim 1, wherein only the first core side portion, the second core side portion, and the core bottom portion of the outer surface of the core are held by the case.

6. The current sensor according to claim 1, wherein only the lateral portion of the first core and the lateral portion of the second core are held by the case on the outer surface of the core.

7. The current sensor according to claim 1, wherein the core has a thickened portion, where the core bottom, the first bottom-side connecting portion, and the second bottom-side connecting portion are thicker than the other portions, and the outer surface of the core has the thickened portion held in the case.

8. The current sensor according to claim 1, wherein the core has a pair of core sides (20c) connecting the inner surface of the core and the outer surface of the core, and the outer surface of the core has portions on the sides of the pair of core sides covered by the case.

9. The current sensor according to claim 1, wherein the core has a pair of core sides (20c) connecting the inner surface of the core and the outer surface of the core, and is a press-formed product in which a plurality of plate materials are stacked in a direction normal to the core sides and pressed, and of the pair of core sides, the core side on the upstream side in the pressing direction when pressed is designated as the upstream surface (201c) and the other core side as the downstream surface (202c), and a mark (203c) for distinguishing the upstream surface and the downstream surface is provided on one of the pair of core sides, and the downstream surface is exposed from the case.

10. The current sensor according to claim 1, wherein a plurality of cores are provided in one direction in the case, and the case is provided with rib portions (502) projecting in a direction intersecting the one direction between adjacent cores in the one direction, so that adjacent cores in the one direction are partitioned and arranged.

11. The current sensor according to claim 1, comprising a substrate (40) on which the detection unit is arranged and which is assembled to the case, wherein the substrate has a substrate hole (404) that penetrates in the thickness direction, the case has a protrusion (521) and a base (522) that project toward the substrate housing chamber (510), the portion covering the core, the protrusion and the base are made of the same material, the substrate is arranged in the substrate housing chamber, the protrusion is inserted through the substrate hole and the substrate is crimped and fixed, and the base is in contact with the substrate.

12. The current sensor according to claim 1, comprising: a substrate (40) on which the detection unit is arranged and which is assembled to the case; and a terminal (70) connected to the substrate and having a portion integrated with the case, wherein the terminal is plate-shaped with one direction as its longitudinal direction and has a wide portion (71) whose length is extended in a direction intersecting the longitudinal direction, holes (72, 73) are formed in the wide portion, and the wide portion including the holes is covered by the case.

13. The current sensor according to claim 1, wherein the case has an exposure hole (52) formed in a portion facing the core, which exposes the core.

14. The current sensor according to claim 13, wherein the case has a projection (53) formed around the exposed hole, projecting in a direction normal to the surface direction of the portion of the case in which the exposed hole is formed.

15. The current sensor according to claim 14, wherein the projection and the exposed hole are formed such that a stepped portion (53a) is formed on the inner surface.

16. The current sensor according to claim 1, wherein the case is formed to have a cavity (51) surrounded by a portion that covers the inner surface of the core, and a recess (560) is formed in the portion of the case that covers the inner surface of the core.

17. The current sensor according to claim 16, wherein the cavity is formed in a portion that covers the inner surface of the core of the first gap-side connecting portion and the second gap-side connecting portion.

18. A current sensor comprising: a core (20) having a core hole (200) through which a current passage (10) through which current flows is inserted, and which collects a magnetic field generated by the current flowing through the current passage; a detection unit (30) that outputs a detection signal corresponding to the magnetic field; and a case (50) made of resin, in which the current passage, the core, and the detection unit are assembled, wherein the core and the case are integrally molded as a single piece, and the core is The core has an inner core surface (20a) that faces the core hole, an outer core surface (20b) that faces the opposite side of the inner core surface, a first gap-forming portion (21) having a first end surface (211) and extending in a first direction, a second gap-forming portion (22) having a second end surface (221) that faces the first end surface and forms a gap (201) between itself and the first end surface and extending in the first direction, a first core lateral portion (23) extending in a second direction intersecting the first direction, a second core lateral portion (24) extending in the second direction, and the space between the portion of the first gap-forming portion opposite to the first end surface and the first core lateral portion. A current sensor comprising: a first gap-side connecting portion (25) positioned and having a curved, rounded shape; a second gap-side connecting portion (26) positioned between the portion of the second gap-forming portion opposite to the second end face and the second core side portion and having a curved, rounded shape; a core bottom portion (27) extending in the first direction; a first bottom-side connecting portion (28) positioned between the first core side portion and the core bottom portion and having a curved, rounded shape; and a second bottom-side connecting portion (29) positioned between the second core side portion and the core bottom portion and having a curved, rounded shape, wherein the portions of the first gap-forming portion and the second gap-forming portion opposite to the core bottom portion, and the portions of the outer surface of the core in the first gap-side connecting portion and the second gap-side connecting portion opposite to the core bottom portion are exposed from the case.

19. The device comprises a core (20) that collects a magnetic field based on the current generated by the flow of current, a detection unit (30) that outputs a detection signal corresponding to the magnetic field, and a case (50) made of resin to which the core and the detection unit are assembled, wherein the core and the case are integrally molded as a single piece, and the core is A core hole (200), a core inner surface (20a) that faces the core hole, a core outer surface (20b) that faces the core inner surface, a first gap forming portion (21) having a first end surface (211) and extending in a first direction, a second gap forming portion (22) having a second end surface (221) that faces the first end surface and forms a gap (201) between itself and the first end surface and extending in the first direction, a first core lateral portion (23) extending in a second direction intersecting the first direction, a second core lateral portion (24) extending in the second direction, and the portion of the first gap forming portion opposite to the first end surface and the first core It has a first gap-side connecting portion (25) positioned between the lateral portion and having a curved, rounded shape; a second gap-side connecting portion (26) positioned between the portion of the second gap-forming portion opposite to the second end face and the second core lateral portion and having a curved, rounded shape; a core bottom portion (27) extending in the first direction; a first bottom-side connecting portion (28) positioned between the first core lateral portion and the core bottom portion and having a curved, rounded shape; and a second bottom-side connecting portion (29) positioned between the second core lateral portion and the core bottom portion and having a curved, rounded shape. A method for manufacturing a current sensor, wherein the portions of the first gap forming portion and the second gap forming portion opposite to the core bottom, and the portions of the outer surface of the core opposite to the core bottom in the first gap side connecting portion and the second gap side connecting portion are exposed from the case, the method comprising: preparing the core; pouring molten resin into a mold to form the case in which the core is insert-molded, wherein the core is prepared having a thickened portion in which the thickness is partially increased,A method for manufacturing a current sensor, wherein, in forming the case, the molten resin first reaches the thickened portion of the core, and the molten resin is poured into the mold such that the direction along the direction normal to the surface direction of the thickened portion is the flow direction of the molten resin.

20. The device comprises a core (20) that collects a magnetic field based on the current generated by the flow of current, a detection unit (30) that outputs a detection signal corresponding to the magnetic field, and a case (50) made of resin to which the core and the detection unit are assembled, wherein the core and the case are integrally molded as a single piece, and the core is A core hole (200), a core inner surface (20a) that faces the core hole, a core outer surface (20b) that faces the core inner surface, a first gap forming portion (21) having a first end surface (211) and extending in a first direction, a second gap forming portion (22) having a second end surface (221) that faces the first end surface and forms a gap (201) between itself and the first end surface and extending in the first direction, a first core lateral portion (23) extending in a second direction intersecting the first direction, a second core lateral portion (24) extending in the second direction, and the portion of the first gap forming portion opposite to the first end surface and the first core It has a first gap-side connecting portion (25) positioned between the lateral portion and having a curved, rounded shape; a second gap-side connecting portion (26) positioned between the portion of the second gap-forming portion opposite to the second end face and the second core lateral portion and having a curved, rounded shape; a core bottom portion (27) extending in the first direction; a first bottom-side connecting portion (28) positioned between the first core lateral portion and the core bottom portion and having a curved, rounded shape; and a second bottom-side connecting portion (29) positioned between the second core lateral portion and the core bottom portion and having a curved, rounded shape. A method for manufacturing a current sensor, wherein the portions of the first gap forming portion and the second gap forming portion opposite to the core bottom, and the portions of the outer surface of the core opposite to the core bottom in the first gap side connecting portion and the second gap side connecting portion are exposed from the case, comprising: preparing the core; and pouring molten resin into a mold (600) to form the case in which the core is insert-molded.A method for manufacturing a current sensor, comprising: arranging the core in the mold such that a portion of the outer surface of the core is located at the highest point in the vertical direction; and pouring the molten resin into the mold such that the molten resin reaches the outer surface portion of the core before the inner surface portion of the core at the highest point in the vertical direction.

Images