KR102723420B1 - Current detection device - Google Patents

Abstract

[Task] To provide a current detection device capable of improving the stability of a connection with a shunt resistor on a substrate.
[Solution] A current detection device (1) comprises: a substrate (3) having a current detection section; a first connection section (51) connected to the substrate; a middle section (53) protruding from the first connection section so as to be perpendicular to the substrate; a second connection section (52) connected to a shunt resistor (4); a connection terminal (5) having a bent section (54) connecting the second connection section and the middle section; a resin holding member (6) integrally formed with the middle section to hold the middle section and supported by the substrate; a fixed terminal (7) having a base held by the holding member and a protrusion (72), the protrusion being soldered to the substrate; a case (2) having an opening (22) exposing the second connection section; and a shunt resistor which is arranged on the outside with respect to the case so as to face the opening and is fastened to the second connection section by a screw member.

Description

Current Detection Device {CURRENT DETECTION DEVICE}

The present invention relates to a current detection device.

Conventionally, there is a technology for detecting current using a shunt resistor. Patent Document 1 discloses a battery control device having a current detection circuit that is electrically connected to a shunt resistor having a plurality of connection pins and detects a battery current flowing through the shunt resistor, a substrate on which the current detection circuit is mounted, and a connector mounted on the substrate.

Japanese Patent Publication No. 2020-201059

In a configuration in which a shunt resistor is electrically connected to a substrate, it is desirable to be able to improve the stability of the connection portion on the substrate.

The purpose of the present invention is to provide a current detection device capable of improving the stability of a connection with a shunt resistor in a substrate.

The current detection device of the present invention is characterized by comprising: a substrate having a current detection portion; a first connection portion electrically connected to the substrate; an intermediate portion protruding from the first connection portion so as to be perpendicular to the substrate; a second connection portion electrically connected to a shunt resistor; a connection terminal having a bent portion connecting the second connection portion and the intermediate portion; a resin holding member integrally formed with the intermediate portion to hold the intermediate portion and further supported by the substrate; a base held by the holding member; a protrusion protruding from the holding member, the protrusion being soldered to the substrate to secure the holding member to the substrate; a case that accommodates the substrate, the connection terminal, the fixed terminal, and the holding member, and further has an opening that exposes the second connection portion; and the shunt resistor that is disposed outside the case so as to face the opening and is further fastened to the second connection portion by a screw member.

In the current detection device related to the present invention, since the retaining member is integrally formed with the middle portion of the connection terminal, the mechanical strength is improved. In addition, since the connection terminal has a bending portion between the middle portion and the second connection portion, it is difficult for an external force acting on the second connection portion to be transmitted to the first connection portion. In addition, the retaining member is firmly fixed to the substrate by the fixed terminal. According to the current detection device related to the present invention, the stability of the connection portion with the shunt resistor in the substrate can be improved.

Fig. 1 is a perspective view of a current detection device related to the embodiment.
Fig. 2 is an exploded perspective view of a current detection device related to the embodiment.
Fig. 3 is a perspective view of a retainer and terminal related to the embodiment.
Fig. 4 is a perspective view of a connection terminal related to the embodiment.
Fig. 5 is a perspective view of a fixed terminal related to the embodiment.
Fig. 6 is a diagram explaining an assembly process of a current detection device related to an embodiment.
Fig. 7 is a cross-sectional view of a current detection device related to the embodiment.

Below, a current detection device related to an embodiment of the present invention will be described in detail with reference to the drawings. In addition, the present invention is not limited to this embodiment. In addition, the components in the following embodiment include those that can be easily assumed by a person skilled in the art or those that are substantially the same.

[Implementation form]

Referring to FIGS. 1 to 7, an embodiment will be described. This embodiment relates to a current detection device. FIG. 1 is a perspective view of a current detection device according to the embodiment, FIG. 2 is an exploded perspective view of a current detection device according to the embodiment, FIG. 3 is a perspective view of a retaining member and a terminal according to the embodiment, FIG. 4 is a perspective view of a connecting terminal according to the embodiment, FIG. 5 is a perspective view of a fixed terminal according to the embodiment, FIG. 6 is a drawing explaining an assembly process of a current detection device according to the embodiment, and FIG. 7 is a cross-sectional view of a current detection device according to the embodiment.

As shown in FIGS. 1 to 3, the current detection device (1) of the present embodiment has a case (2), a substrate (3), a shunt resistor (4), a connection terminal (5), a retaining member (6), a fixed terminal (7), and a screw member (8). The current detection device (1) is disposed, for example, in a battery of a vehicle and detects a charge/discharge current of the battery. The current detection device (1) is a so-called shunt-type current sensor. That is, the current detection device (1) causes a current to flow through a shunt resistor (4), and measures a current value using Ohm's law from a voltage drop when current is passed through it and the resistance value of the shunt resistor (4).

The shape of the shunt resistor (4) illustrated is a rectangular flat plate shape. A bus bar is connected to each end of the shunt resistor (4). One bus bar is connected to, for example, a negative electrode of a battery. The other bus bar is connected to, for example, a grounding portion of a vehicle body or the like. Based on the current value detected by the current detection device (1), the battery is monitored and controlled.

As shown in Fig. 2, the current detection device (1) of the present embodiment has a pair of connection terminals (5) that connect a shunt resistor (4) and a substrate (3). A current detection unit (31) that the substrate (3) has is connected to the shunt resistor (4) via the connection terminal (5). The current detection unit (31) is, for example, a current detection circuit. The current detection device (1) of the present embodiment has a holding member (6) that holds the connection terminal (5). As described below, the holding member (6) can improve the current detection accuracy and the stability of the connection location between the connection terminal (5) and the substrate (3).

The case (2) accommodates a substrate (3), a connection terminal (5), a retaining member (6), and a fixed terminal (7). The case (2) is formed of, for example, an insulating synthetic resin. The exemplified case (2) has a rectangular shape. One end of the case (2) has an insertion port (21). The substrate (3), the connection terminal (5), the retaining member (6), and the fixed terminal (7) are inserted into the case (2) from the insertion port (21). On the inside of the case (2), a guide portion (23) for guiding the substrate (3) and an engagement portion for engaging the substrate (3) are provided.

In the following description, the insertion direction of the substrate (3) into the case (2) is referred to as the “first direction (X).” The first direction (X) is the axial direction of the cylindrical case (2). In addition, the width direction of the case (2) and the substrate (3) is referred to as the “second direction (Y),” and the height direction of the case (2) is referred to as the “third direction (Z).” The third direction (Z) is the thickness direction of the substrate (3). The first direction (X), the second direction (Y), and the third direction (Z) are orthogonal to each other.

In the case (2), a recessed portion (24) for accommodating a shunt resistor (4) is provided on the inside of the first direction (X). The recessed portion (24) is formed on the outer surface of the case (2). The shape of the recessed portion (24) in a plan view is a rectangle according to the shape of the shunt resistor (4). Two openings (22) are provided in the recessed portion (24). The two openings (22) are arranged along the second direction (Y). The shape of the openings (22) is, for example, a rectangle. The substrate (3) is inserted into the case (2) to a position where the second connection portion (52) of the connection terminal (5) faces the opening (22). The case (2) supports the substrate (3) in a state where the second connection portion (52) is exposed from the opening (22).

The case (2) holds two nuts (10). The nuts (10) are pressed into the case (2) along the first direction (X). The shunt resistor (4) has a pair of first through holes (41), a pair of second through holes (42), and a pair of third through holes (43). The through holes (41, 42, 43) are arranged along the second direction (Y). The first through hole (41) is arranged at the innermost side, and the third through hole (43) is arranged at the outermost side.

The first through hole (41) is a through hole corresponding to the screw member (8). The screw member (8) is inserted through the first through hole (41) and screw-connected with the second connection portion (52) of the connection terminal (5). The second through hole (42) is a through hole corresponding to the screw member (11). The screw member (11) is a fastening member that fixes the shunt resistor (4) to the case (2). The screw member (11) is inserted through the second through hole (42) and screw-connected with the screw hole of the case (2). The case (2) may hold a nut corresponding to the screw member (11).

The third through hole (43) is a through hole corresponding to the nut (10). Each of the above bus bars is fixed to the shunt resistor (4) by a screw member (not shown) and a nut (10). Each bus bar may have a through hole corresponding to the third through hole (43). In this case, the screw member is inserted into the through hole of the bus bar and the third through hole (43) and is screw-connected with the nut (10).

A connector (32) is arranged on the substrate (3). The current detection unit (31) may be connected to an external monitoring device via the connector (32). The cover (9) engages with the case (2) and closes the insertion port (21) of the case (2). The cover (9) has a through hole corresponding to the connector (32).

As shown in Fig. 3, the retaining member (6) retains two connection terminals (5) and one fixed terminal (7). The exemplified retaining member (6) is molded from an insulating synthetic resin. The retaining member (6) is integrated with the two connection terminals (5) and the fixed terminal (7) by insert molding. The fixed terminal (7) is insulated from the connection terminal (5). The shape of the retaining member (6) is approximately a rectangular parallelepiped.

Regarding the connection terminal (5), the retaining member (6), and the fixed terminal (7), the description will be made using the respective directions (X, Y, Z) in a state where the retaining member (6) is fixed to the substrate (3) and accommodated in the case (2). The two connection terminals (5) have a first connection terminal (5A) and a second connection terminal (5B). The two connection terminals (5) are arranged at the first end (6a) of the retaining member (6). The fixed terminal (7) is arranged at the second end (6b) of the retaining member (6). The first end (6a) and the second end (6b) are ends of the retaining member (6) in the first direction (X). That is, the fixed terminal (7) is arranged at a position distant from the two connection terminals (5) in the first direction (X). The fixed terminal (7) is arranged between two female screw portions (56) in the second direction (Y). That is, the fixed terminal (7) is arranged between two female screw portions (56) when the substrate (3) is viewed flat.

Two connecting terminals (5) are arranged along the second direction (Y). The first connecting terminal (5A) is arranged at one end in the second direction (Y), and the second connecting terminal (5B) is arranged at the other end in the second direction (Y). The fixed terminal (7) is arranged at the center of the second direction (Y). That is, the position of the fixed terminal (7) in the second direction (Y) is a position between the first connecting terminal (5A) and the second connecting terminal (5B), for example, a central position.

As shown in Fig. 4, the connection terminal (5) has a first connection portion (51), a second connection portion (52), a middle portion (53), and a bend portion (54). The connection terminal (5) is formed of a conductive metal such as copper. The connection terminal (5) is formed of, for example, a single metal plate. The first connection portion (51) is physically and electrically connected to the substrate (3). The shape of the exemplified first connection portion (51) is a flat plate shape or a prism shape. The first connection portion (51) is inserted into a through hole of the substrate (3) and soldered to the substrate (3). The first connection portion (51) is connected to the current detection portion (31) via a circuit pattern of the substrate (3).

The second connecting portion (52) is connected to the shunt resistor (4) by a screw member (8). The illustrated second connecting portion (52) has a flat body (55) and a cylindrical female screw portion (56). The shape of the body (55) in a plan view is rectangular. The female screw portion (56) protrudes from the center of the body (55) toward the first connecting portion (51). A female screw is formed on the inner surface of the female screw portion (56) by tapping. An inlet slope (56a) is provided at the entrance of the female screw portion (56).

The intermediate portion (53) is sealed in the resin of the retaining member (6) and is retained by the retaining member (6). The intermediate portion (53) is a portion between the first connecting portion (51) and the second connecting portion (52). The intermediate portion (53) is continuous with the first connecting portion (51) and is positioned on an extension of the first connecting portion (51). The shape of the intermediate portion (53) as exemplified is a flat plate shape. The intermediate portion (53) has a tapered shape whose width gradually narrows as it goes toward the first connecting portion (51) along the third direction (Z). The side surface of the intermediate portion (53) has a plurality of inclined surfaces (53a). The inclined surfaces (53a) are inclined so as to get closer to the center line of the intermediate portion (53) as they get closer to the first connecting portion (51) along the third direction (Z). At the end of the middle part (53), a step part (53b) is provided. The step part (53b) is arranged at the end on the side of the second connecting part (52) of the middle part (53).

The bent portion (54) connects the middle portion (53) and the second connecting portion (52). The illustrated bent portion (54) is bent so as to make the second connecting portion (52) orthogonal to the first connecting portion (51). The first connecting portion (51) and the middle portion (53) extend along the third direction (Z), and the second connecting portion (52) extends along the first direction (X). The shape of the bent portion (54) in a side view is an arc-shaped curved shape. The width (Wd2) of the bent portion (54) is narrower than the width (Wd1) of the middle portion (53) and also narrower than the width (Wd3) of the second connecting portion (52). That is, the bent portion (54) has lower rigidity than the middle portion (53) and the second connecting portion (52), and is prone to elastic deformation.

As shown in Fig. 5, the fixed terminal (7) has a base (71) and a protrusion (72). The fixed terminal (7) is formed of a metal plate. The fixed terminal (7) may have conductivity. The base (71) is sealed in the resin of the retaining member (6) and is retained by the retaining member (6). The protrusion (72) is a portion that protrudes from the retaining member (6) along the third direction (Z).

The base (71) has a flat shape and extends along the third direction (Z). The base (71) has a tapered shape whose width gradually narrows as it approaches the protrusion (72) along the third direction (Z). The side surface of the base (71) has a plurality of inclined surfaces (71a). The inclined surfaces (71a) are inclined so as to approach the center line of the base (71) as they approach the protrusion (72) along the third direction (Z). A step (71b) is provided at an end of the base (71). The step (71b) is arranged at an end on the opposite side of the protrusion (72) in the base (71).

The shape of the protrusion (72) illustrated is a flat shape or a prism shape. The protrusion (72) is inserted into a through hole of the substrate (3) and soldered to the substrate (3). The fixed terminal (7) fixes the retaining member (6) to the substrate (3) by soldering the protrusion (72) to the substrate (3).

As shown in Fig. 3, the first connection portion (51) of the connection terminal (5) and the protrusion portion (72) of the fixed terminal (7) protrude from the retaining member (6) along the third direction (Z). The first connection portion (51) and the protrusion portion (72) protrude toward the first side (Z1). The first side (Z1) is the substrate (3) side when viewed from the retaining member (6). That is, the first connection portion (51) and the protrusion portion (72) protrude from the retaining member (6) toward the substrate (3) side.

The second connection portion (52) and the bent portion (54) of the connection terminal (5) protrude from the retaining member (6) along the third direction (Z). The second connection portion (52) and the bent portion (54) protrude toward the second side (Z2). The second side (Z2) is the shunt resistor (4) side when viewed from the retaining member (6). That is, the second connection portion (52) and the bent portion (54) protrude from the retaining member (6) toward the shunt resistor (4) side. The main body (55) and the female screw portion (56) of the second connection portion (52) face the retaining member (6) in the third direction (Z). The female screw portion (56) protrudes from the main body (55) toward the retaining member (6) along the third direction (Z).

The support member (6) has three leg parts (61, 62, 63) protruding toward the first side (Z1). The three leg parts (61, 62, 63) are supported by the substrate (3). The first leg part (61) is arranged on the first end (6a) side, and the second leg part (62) and the third leg part (63) are arranged on the second end (6b) side.

The first leg (61) is located between the two first connecting portions (51). The first leg (61) protrudes from the first end (6a) toward the first side (Z1). The shape of the first leg (61) when viewed from the first direction (X) is rectangular. The front end surface of the first leg (61) is mounted on the substrate (3) and supported by the substrate (3).

The second leg portion (62) and the third leg portion (63) are arranged at the corner portion of the retaining member (6). The second leg portion (62) and the third leg portion (63) are arranged with the protrusion portion (72) of the fixed terminal (7) sandwiched therebetween. In other words, the second leg portion (62) is arranged on one side of the second direction (Y) with respect to the protrusion portion (72), and the third leg portion (63) is arranged on the other side of the second direction (Y) with respect to the protrusion portion (72). When the retaining member (6) is viewed from the first side (Z1), the shapes of the second leg portion (62) and the third leg portion (63) are approximately L-shaped and are bent at right angles. The second leg portion (62) and the third leg portion (63) each have a portion extending in the first direction (X) and a portion extending in the second direction (Y). The end faces of the second leg portion (62) and the third leg portion (63) are mounted on the substrate (3) and supported by the substrate (3).

The retaining member (6) has a projection (64, 65) protruding toward the first side (Z1). The projection (64) protrudes from the second leg portion (62), and the projection (65) protrudes from the third leg portion (63). The shape of the projection (64, 65) illustrated is a cylindrical shape. The substrate (3) has a positioning portion corresponding to the projection (64, 65). The positioning portion is a concave portion or a hole portion formed in the substrate (3). By inserting the projection (64, 65) into the positioning portion, the retaining member (6) is positioned relative to the substrate (3).

As shown in Fig. 2, the retaining member (6) is mounted on the first surface (3a) of the substrate (3). The substrate (3) has through holes corresponding to the connecting terminal (5) and the fixed terminal (7). The first connecting portion (51) of the connecting terminal (5) and the protrusion (72) of the fixed terminal (7) are inserted into the corresponding through holes. The first connecting portion (51) and the protrusion (72) are fixed by soldering to the second surface (3b) of the substrate (3). The first connecting portion (51) is connected to the circuit pattern of the substrate (3). The protrusion (72) is connected to a land for fixing, etc.

In Fig. 6, a case (2) is shown in which a connection terminal (5) and the like are accommodated in a prescribed position. The second connection portion (52) of the connection terminal (5) is exposed to the opening (22) of the case (2). The shunt resistor (4) is mounted in a concave portion (24) of the case (2) so as to face the opening (22) and is fixed to the case (2) by a screw member (11). The second connection portion (52) of each connection terminal (5) is connected to the shunt resistor (4) by a screw member (8). The screw member (8) is inserted into the first through hole (41) of the shunt resistor (4) and is screwed into the female screw portion (56) of the connection terminal (5).

Fig. 7 shows an X-Z cross-section including a screw member (8) and a connection terminal (5). The cross-section of Fig. 7 is a cross-section along the central axis of the screw member (8). As shown in Fig. 7, the first through hole (41) of the shunt resistor (4) faces the female screw portion (56) in the third direction (Z). The screw member (8) is screw-connected with the female screw portion (56) and brings the main body (55) of the connection terminal (5) into contact with the shunt resistor (4). The screw member (8) is conductive and can electrically connect the shunt resistor (4) and the second connection portion (52).

The first connection portion (51) of the connection terminal (5) is connected to the substrate (3) by a solder (12) and is also fixed to the substrate (3). The middle portion (53) protrudes from the first connection portion (51) toward the shunt resistor (4) so as to be perpendicular to the substrate (3). The protrusion portion (72) of the fixed terminal (7) is fixed to the substrate (3) by a solder (12). The retaining member (6) is mounted on the substrate (3) and is also fixed to the substrate (3) by a solder (12).

Here, when the screw member (8) is screw-connected to the female screw portion (56), an external force is applied to the second connecting portion (52). The connecting terminal (5) and the retaining member (6) of the present embodiment can suppress this external force from being transmitted to the first connecting portion (51). When an external force is applied to the second connecting portion (52), the bent portion (54) of the connecting terminal (5) can elastically deform and absorb the external force. In addition, when the screw member (8) is inserted into the female screw portion (56) in an inclined position, the bent portion (54) elastically deforms, thereby allowing the female screw portion (56) to follow the screw member (8).

In addition, the retaining member (6) is integrally formed with the middle part (53) of the connecting terminal (5) and retains the middle part (53). Therefore, the retaining member (6) can suppress the transmission of an external force acting on the second connecting part (52) to the first connecting part (51). For example, the retaining member (6) is supported by the substrate (3) and can support the middle part (53) by resisting a force in the third direction (Z).

In addition, the retaining member (6) is fixed to the substrate (3) via the fixed terminal (7). Therefore, the force received by the retaining member (6) is distributed to the connection portion between the fixed terminal (7) and the substrate (3). The fixed terminal (7) is arranged to be spaced apart from the middle portion (53) of the connecting terminal (5) in the first direction (X). Therefore, the fixed terminal (7) can stabilize the retaining member (6) against the force or moment in the first direction (X).

The current detection device (1) of the present embodiment can reduce the influence of external force on the connection point between the connection terminal (5) and the substrate (3), and improve the stability of the connection point. Therefore, the current detection device (1) of the present embodiment can secure current measurement precision by transmitting an electric signal from the shunt resistor (4) to the substrate (3) without compromising precision. In addition, the current detection device (1) of the present embodiment can reduce the exclusive area of the device by integrating the shunt resistor (4) into the upper surface of the case (2).

As described above, the current detection device (1) of the present embodiment has a substrate (3) having a current detection portion (31), a connection terminal (5), a resin-made retaining member (6), a fixed terminal (7), a case (2), and a shunt resistor (4). The connection terminal (5) has a first connection portion (51), a middle portion (53), a second connection portion (52), and a bend portion (54). The first connection portion (51) is electrically connected to the substrate (3). The middle portion (53) protrudes from the first connection portion (51) so as to be perpendicular to the substrate (3). The second connection portion (52) is electrically connected to the shunt resistor (4). The bend portion (54) connects the second connection portion (52) and the middle portion (53).

The retaining member (6) is integrally formed with the middle part (53) to retain the middle part (53) and is also supported by the substrate (3). The fixed terminal (7) has a base (71) retained by the retaining member (6) and a protrusion (72) protruding from the retaining member (6). The fixed terminal (7) secures the retaining member (6) to the substrate (3) by soldering the protrusion (72) to the substrate (3). The case (2) accommodates the substrate (3), the connection terminal (5), the fixed terminal (7), and the retaining member (6). The case (2) has an opening (22) that exposes the second connection part (52). The shunt resistor (4) is arranged on the outside with respect to the case (2) so as to face the opening (22). The shunt resistor (4) is fastened to the second connection part (52) by a screw member (8).

In the current detection device (1) of the present embodiment, since the retaining member (6) is integrally formed with the middle portion (53) of the connection terminal (5), the mechanical strength is improved. In addition, since the connection terminal (5) has a bending portion (54) between the middle portion (53) and the second connection portion (52), an external force acting on the second connection portion (52) is difficult to transmit to the first connection portion (51). In addition, the retaining member (6) is firmly fixed to the substrate (3) by the fixed terminal (7). Therefore, the current detection device (1) of the present embodiment can improve the stability of the connection portion with the shunt resistor (4) in the substrate (3). For example, the stability of the soldering point between the first connection portion (51) and the substrate (3) is improved.

The second connecting portion (52) of the present embodiment has a flat body (55) that comes into contact with the shunt resistor (4), and a cylindrical female screw portion (56) that protrudes from the body (55) toward the substrate (3). The shunt resistor (4) has a first through hole (41), and the first through hole (41) is positioned opposite the female screw portion (56). The screw member (8) is inserted into the first through hole (41) and screw-connected to the female screw portion (56) to connect the second connecting portion (52) and the shunt resistor (4). In this configuration, the external force when the screw member (8) is screw-connected to the female screw portion (56) is absorbed by the bending portion (54).

The retaining member (6) of the present embodiment retains the middle portion (53) of two connecting terminals (5). The two female screw portions (56) face the retaining member (6). The fixed terminal (7) is arranged between the two female screw portions (56) when the substrate (3) is viewed flat. Therefore, the fixed terminal (7) can appropriately support the retaining member (6) against an external force when the screw member (8) is screw-connected to each female screw portion (56).

In addition, the shape of the bent portion (54) is not limited to the exemplified shape. For example, the number of bending points of the bent portion (54) is not limited to one. The bent portion (54) may be bent at two or more points.

The shape of the retaining member (6) is not limited to the exemplified shape. The retaining member (6) may retain a plurality of fixed terminals (7). In this case, the plurality of fixed terminals (7) are each soldered to the substrate (3).

The contents disclosed in the above embodiments can be appropriately combined and implemented.

1: Current detection device
2 : Case
3: Substrate
3a: Page 1
3b: Second side
4: Shunt resistance
5: Connection terminal
5A: 1st connection terminal
5B: 2nd connection terminal
6: Absence of visibility
6a: Section 1
6b: 2nd section
7: Fixed terminal
8: Screw member
9 : Cover
10 : Nuts
11: Screw member
21 : Insertion hole
22 : Opening
41: First through hole
42: Second through hole
43: Third through hole
51: 1st connector
52: Second connector
53 : Middle part
53a : Slope
54 : Bend
55 : Body
56 : Female screw
61: 1st bridge section
62: Second bridge section
63: Third bridge
71 : Donation
71a : Slope
72 : Protrusion
X: 1st direction
Y: 2nd direction
Z: Third direction

Claims (3)

A substrate having a current detection unit,
A connection terminal having a first connection portion electrically connected to the substrate, an intermediate portion protruding from the first connection portion so as to be perpendicular to the substrate, a second connection portion electrically connected to a shunt resistor, and a bent portion connecting the second connection portion and the intermediate portion,
A resin-made retaining member that is integrally formed with the above intermediate portion and supports the above intermediate portion and is also supported by the substrate;
A fixed terminal having a base supported by the above-mentioned retaining member and a protrusion protruding from the above-mentioned retaining member, the protrusion being soldered to the substrate to secure the retaining member to the substrate,
A case that accommodates the substrate, the connection terminal, the fixed terminal, and the retaining member, and also has an opening that exposes the second connection portion;
The shunt resistor is positioned on the outside of the case so as to face the opening, and is also fastened to the second connecting portion by a screw member.
A current detection device characterized by comprising: In paragraph 1,
The second connecting portion has a flat body in contact with the shunt resistor and a cylindrical female screw portion protruding from the body toward the substrate side.
The above shunt resistor has a through hole, and the through hole is opposite to the female screw portion.
A current detection device in which the screw member is inserted into the through hole and also screw-connected to the female screw portion to connect the second connection portion and the shunt resistor. In the second paragraph,
The above-mentioned retaining member retains the middle part of the two above-mentioned connecting terminals,
The two above screw parts are facing the above retaining member,
The above fixed terminal is a current detection device arranged between two of the female screw portions when the above substrate is flat.