JP2021173396A - Press-fit structure and battery state detection device - Google Patents

Abstract

To provide a press-fit structure capable of implementing an excellent electrical connection.SOLUTION: A press-fit structure 1 comprises a shunt resistor 15 and a harness connection terminal 9. A through-hole 41 is formed in the shunt resistor 15. The harness connection terminal 9 is press-fitted into the through-hole 41 from one side to the other side in an axial direction of the through-hole 41 and protrudes from the shunt resistor 15 toward the other side. The through-hole 41 includes a first hole part 43 and a second hole part 45. The harness connection terminal 9 is inserted into the first hole part 43 so as to be meshed into the shunt resistor 15. The second hole part 45 is disposed adjacently to a side where the harness connection terminal 9 protrudes from the shunt resistor 15, with respect to the first hole part 43. A hole diameter of the second hole part 45 is larger than a hole diameter of the first hole part 43.SELECTED DRAWING: Figure 5

Description

The present invention relates to a press-fitting structure and a battery state detecting device.

Conventionally, a structure in which a press-fitting member is press-fitted into a through hole of a plate-shaped member or the like has been known. Patent Document 1 discloses a battery terminal having this type of press-fitting structure. Patent Document 2 discloses a battery state detection device having this type of press-fitting structure.

The battery terminal of Patent Document 1 includes a metal plate-shaped member having a through hole and a metal bolt (press-fitting member). The bolt is press-fitted while being inserted into the through hole of the plate-shaped member, whereby the bolt is attached to the plate-shaped member. A current sensor and terminals are attached to this bolt with nuts or the like. The current sensor and terminals are electrically connected to the plate-shaped member via bolts.

The battery state detecting device of Patent Document 2 includes a shunt resistor (plate-shaped member) and a harness connecting terminal (press-fitting member). The shunt resistor is composed of a first conductor, a second conductor, and a resistor. The first conductor, the second conductor, and the resistor are each formed in a flat plate shape. The second conductor has a through hole. The harness connection terminal is configured as a conductive bolt. The harness connection terminal is fixed to the second conductor by being press-fitted while being inserted into the through hole of the second conductor. The harness connection terminal fixed to the second conductor is passed through the through hole of the terminal of the harness, and the harness is electrically and mechanically connected to the harness connection terminal.

Japanese Patent No. 5675750 International Publication No. 2017/002356

In the configuration of Patent Document 1, burrs may be generated around the through hole in the plate-shaped member due to press-fitting of the bolt into the through hole into the plate-shaped member. In this case, the burr protrudes from the plate-shaped member in the direction in which the bolt is press-fitted into the through hole. Even in the configuration of Patent Document 2, burrs may be generated around the through hole in the shunt resistor (second conductor) due to press fitting. In this case, the burr protrudes from the plate-shaped member in the direction in which the harness connection terminal is press-fitted into the through hole.

If a burr intervenes between the plate-shaped member or shunt resistor and the terminal, the electrical connection between the plate-shaped member or shunt resistor and the terminal may become inappropriate. In addition, there was a concern that other problems due to burrs, such as loose nuts, would occur.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a press-fitting structure capable of realizing a good electrical connection.

Means and effects to solve problems

The problem to be solved by the present invention is as described above, and next, the means for solving this problem and its effect will be described.

According to the first aspect of the present invention, a press-fitting structure having the following configuration is provided. That is, this press-fitting structure includes a plate-shaped member and a press-fitting member. A through hole is formed in the plate-shaped member. The press-fitting member is press-fitted into the through hole from one side in the axial direction of the through hole toward the other side, and projects from the plate-shaped member toward the other side. The through hole includes a first hole portion and a second hole portion. The first hole portion is coupled to the press-fitting member by the press-fitting. The second hole portion is arranged adjacent to the first hole portion on the side where the press-fit member protrudes from the plate-shaped member, and has a hole diameter larger than the hole diameter of the first hole portion.

As a result, even if burrs are generated in the vicinity of the press-fitting portion of the plate-shaped member due to the press-fitting of the press-fitting member, the burrs can be accommodated in the space corresponding to the second hole portion. Therefore, when another member is attached to the plate-shaped member via the press-fitting member, it is possible to prevent burrs from intervening between the plate-shaped member and the other member. As a result, good electrical connection between the plate-shaped member and other members can be realized.

The press-fitting structure preferably has the following configuration. That is, the first hole portion opens on one surface of the plate-shaped member. The second hole portion is opened in the plate-shaped member on a surface opposite to the opening of the first hole portion.

Thereby, a simple configuration of the through hole can be realized.

According to the second aspect of the present invention, a battery state detecting device having the following configuration is provided. This battery state detecting device includes the above-mentioned press-fitting structure. The battery state detection device further includes a post connection terminal, a harness connection terminal, a shunt resistor, a circuit board, a connector, and a casing. The post connection terminal is connected to the battery post. The harness connection terminal is connected to the harness. The shunt resistor is connected to each of the post connection terminal and the harness connection terminal. The circuit board is connected to the shunt resistor. The connector is connected to the circuit board. The circuit board is provided in the casing. The shunt resistor is the plate-shaped member. The harness connection terminal is the press-fitting member.

As a result, it is possible to obtain a battery state detecting device capable of ensuring a good electrical connection with respect to the plate-shaped member.

The perspective view which shows the overall structure of the battery state detection apparatus to which the press-fitting structure which concerns on one Embodiment of this invention is applied. (A) A perspective view showing a configuration of a shunt resistor. (B) A partially enlarged cross-sectional view of the shunt resistor of (a). The perspective view which shows the state which the harness connection terminal is attached to the shunt resistor. The perspective view which shows the structure of the harness connection terminal. A cross-sectional view showing a state in which a harness connection terminal is attached to a shunt resistor.

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing the overall configuration of the battery state detection device 3 to which the press-fitting structure 1 according to the embodiment of the present invention is applied. FIG. 2A is a perspective view showing the configuration of the shunt resistor 15. FIG. 2B is a partially enlarged cross-sectional view of the shunt resistor 15 of FIG. 2A.

The press-fitting structure 1 of the present embodiment is applied to the battery state detection device 3. The battery state detection device 3 is attached to, for example, a battery post of a battery mounted on an automobile or the like.

The battery state detection device 3 can detect the state of the battery by detecting the magnitude of the current and the like. The battery state detection device 3 outputs the detection result to an external device (not shown). Examples of the output destination external device include an engine control unit (ECU) that controls an automobile engine.

As shown in FIG. 1, the battery state detection device 3 includes a post connection terminal 5, a harness connection terminal (press-fitting member) 9, a connector 11, a casing 13, a shunt resistor (plate-shaped member) 15, and a circuit board. 17 and are provided as the main configurations.

The post connection terminal 5 is connected to a battery post of a battery (not shown). The post connection terminal 5 is formed by pressing, bending, or forging a metal plate. The post connection terminal 5 is provided with a post connection portion 21 that connects to the battery post and a plate-shaped connection portion 23 that extends from the post connection portion 21.

The post connection portion 21 is formed in a substantially cylindrical shape extending in the vertical direction. The post connection 21 can hold the battery post. The post connection portion 21 is tightened with a tightening bolt or the like with the battery post inserted inside. As a result, the post connection portion 21 is electrically and mechanically connected to the battery post.

The connecting portion 23 is provided so as to extend from the lower end of the outer peripheral surface of the post connecting portion 21 in a direction away from the post connecting portion 21. The connecting portion 23 is connected to the shunt resistor 15 (protruding portion 25) and functions as a connecting portion with the shunt resistor 15.

The harness connection terminal 9 is composed of a conductive bolt (for example, a stud bolt). The harness connection terminal 9 is electrically connected to the harness 7. The harness connection terminal 9 is arranged with its axial direction oriented in the vertical direction, and is attached to the shunt resistor 15 on the lower side. Further, the harness connection terminal 9 is connected to the harness 7 on the upper side.

Although the harness 7 is simply drawn in FIG. 1, the harness 7 is composed of, for example, an electric wire. A terminal 27 is provided at the end of the harness 7. A hole 29 through which the harness connection terminal 9 can pass is formed in the terminal 27. The harness connection terminal 9 is inserted into the hole 29 of the terminal 27, and in this state, the nut 31 and the like are tightened to the harness connection terminal 9. As a result, the shunt resistor 15 and the terminal 27 of the harness 7 (a member different from the shunt resistor 15) can be electrically and mechanically connected via the harness connection terminal 9.

The connector 11 is configured as an interface for outputting the detection result of the battery state detection device 3 to the ECU or the like. Inside, an output terminal connected to the circuit board 17 is provided.

The casing 13 is an elongated member formed in a substantially rectangular parallelepiped shape. The casing 13 is made of, for example, a synthetic resin. A circuit board 17 or the like is provided on the casing 13. In the present embodiment, the casing 13 is formed in a hollow shape with the lower side open. A part of the shunt resistor 15 and the circuit board 17 and the like are housed inside the casing 13. The shunt resistor 15 is provided with a protruding portion 25 projecting from the casing 13 toward the post connection terminal 5. The protruding portion 25 is connected to the connecting portion 23 of the post connection terminal 5.

As shown in FIG. 2A, the shunt resistor 15 is composed of a first conductor 33, a second conductor 35, and a resistor 37 having a known resistance value. The first conductor 33, the second conductor 35, and the resistor 37 are each formed in a flat plate shape. The above-mentioned protrusion 25 is formed on the first conductor 33. As shown in FIG. 1, a part of the second conductor 35 is exposed to the outside of the casing 13. A harness connection terminal 9 is attached to the exposed portion of the second conductor 35. Details of this configuration will be described later.

The resistor 37 is arranged between the first conductor 33 and the second conductor 35. The first conductor 33, the second conductor 35, and the resistor 37 are arranged in substantially the same plane. The resistor 37 is joined to the first conductor 33 and also to the second conductor 35. In this way, the first conductor 33, the resistor 37, and the second conductor 35 are connected side by side, and the entire shunt resistor 15 is formed in the shape of an elongated plate. The direction in which the first conductor 33, the resistor 37, and the second conductor 35 are arranged coincides with the longitudinal direction of the shunt resistor 15.

Although not shown, each of the first conductor 33 and the second conductor 35 of the shunt resistor 15 is provided with a substrate connection terminal for connecting to the circuit board 17. Through these board connection terminals, the shunt resistor 15 is mechanically and electrically connected to the circuit board 17.

The circuit board 17 is arranged below the shunt resistor 15 inside the casing 13. An electronic circuit is mounted on the circuit board 17. With this electronic circuit, the potential difference between the first conductor 33 and the second conductor 35 can be measured via the substrate connection terminal. The measured potential difference information is used to acquire the magnitude of the current flowing through the resistor 37 of the shunt resistor 15.

The circuit board 17 is connected to an output terminal provided inside the connector 11. The circuit board 17 calculates the magnitude of the current in the resistor 37 based on the potential difference generated in the shunt resistor 15. The circuit board 17 detects the state of the battery based on the potential difference, the magnitude of the current, and the like. The circuit board 17 outputs the obtained detection result to the ECU or the like via the output terminal of the connector 11.

Next, a configuration in which the harness connection terminal 9 is attached to the shunt resistor 15 will be described. FIG. 3 is a perspective view showing a state in which the harness connection terminal 9 is attached to the shunt resistor 15. FIG. 4 is a perspective view showing the configuration of the harness connection terminal 9. FIG. 5 is a cross-sectional view showing a state in which the harness connection terminal 9 is attached to the shunt resistor 15.

As shown in FIG. 1, the harness connection terminal 9 is attached to the second conductor 35 in the shunt resistor 15. As shown in FIG. 2, a through hole 41 is formed in the second conductor 35. The through hole 41 penetrates the plate-shaped second conductor 35 in the thickness direction. The harness connection terminal 9 is press-fitted into the through hole 41 from one side in the thickness direction (one side in the axial direction of the through hole 41) toward the other side. The harness connection terminal 9 press-fitted into the through hole 41 projects from the second conductor 35 toward the other side. The harness connection terminal 9 and the second conductor 35 are each made of a metal member.

The harness connection terminal 9 is fixed to the second conductor 35 by press fitting into the through hole 41. As a result, one end of the harness connection terminal 9 in the longitudinal direction is connected to the second conductor 35. A portion other than this connecting portion is arranged so as to protrude from the second conductor 35. The direction in which the harness connection terminal 9 is press-fitted into the through hole 41 coincides with the direction in which the harness connection terminal 9 protrudes from the second conductor 35 after press-fitting.

As shown in FIGS. 2A and 2B, the through holes 41 are arranged so that their axial directions coincide with the thickness directions of the second conductor 35. The through hole 41 is formed in a circular shape. The through hole 41 is formed as a stepped hole, and its inner diameter differs between one side and the other side in the depth direction. Specifically, the through hole 41 is formed so that the upper hole diameter is larger than the lower hole diameter in a state where the through hole 41 is oriented up and down as shown in FIG. 2A. ..

In the present embodiment, the through hole 41 is composed of a first hole portion 43 and a second hole portion 45. The first hole portion 43 and the second hole portion 45 are adjacent to each other in the axial direction of the through hole 41. The hole diameter D2 of the second hole 45 is larger than the hole diameter D1 of the first hole 43 (D2> D1). The hole diameter D2 of the second hole portion 45 is preferably about 1.2 times or more larger than the hole diameter D1 of the first hole portion 43.

The first hole portion 43 forms an opening in the second conductor 35. The harness connection terminal 9 is inserted into the through hole 41 through this opening and press-fitted. A large-diameter portion formed at one end in the longitudinal direction of the harness connection terminal 9 is inserted so as to be in pressure contact with the inner wall of the first hole portion 43. By such press fitting, the first hole portion 43 is coupled to the harness connection terminal 9. Further, a part of the harness connection terminal 9 (a protrusion 53 described later) bites into the periphery of the opening formed by the first hole 43 in the second conductor 35 with the press fitting.

The second hole portion 45 is arranged adjacent to the upper side (the side where the harness connection terminal 9 protrudes from the shunt resistor 15) with respect to the first hole portion 43. The second hole 45 is larger than the first hole 43. When the harness connection terminal 9 is attached to the through hole 41, a space 47 is formed between the inner wall of the second hole 45 and the harness connection terminal 9. In other words, unlike the first hole 43, the inner wall of the second hole 45 does not come into contact with the harness connection terminal 9. The second hole 45 forms an opening in the second conductor 35. The surface of the second hole 45 forming the opening in the second conductor 35 is located on the opposite side of the through hole 41 in the axial direction from the surface of the first hole 43 forming the opening in the second conductor 35. The second hole portion 45 can be formed by, for example, counterbore processing.

Although details will be described later, the harness connection terminal 9 has a screw shaft portion 55 as shown in FIG. Both the hole diameter D1 of the first hole portion 43 and the hole diameter D2 of the second hole portion 45 are larger than the maximum diameter D3 of the screw shaft portion 55. Therefore, the screw shaft portion 55 can be inserted into the through hole 41 without any problem.

As shown in FIG. 4, the harness connection terminal 9 includes a flange portion 51, a protrusion portion 53, and a screw shaft portion 55. The flange portion 51, the protrusion 53, and the screw shaft portion 55 are arranged in order in the axial direction of the harness connection terminal 9.

The flange portion 51 is arranged on one side of the harness connection terminal 9 in the axial direction (longitudinal direction). The flange portion 51 is formed in a disk shape. The diameter of the flange portion 51 is larger than the hole diameter D1 of the first hole portion 43 and larger than the hole diameter D2 of the second hole portion 45.

The protrusion 53 is formed on the surface of the flange 51 on the side connected to the screw shaft 55. The protrusion 53 is formed in a star shape when viewed in the axial direction of the harness connection terminal 9. The protrusion 53 is provided so as to project from the flange 51 to the other side in the axial direction of the harness connection terminal 9 in a state where the center of the protrusion 53 substantially coincides with the center of the flange 51.

The screw shaft portion 55 is arranged so as to project from one side surface of the flange portion 51. The central axis of the screw shaft portion 55 coincides with the center of the flange portion 51. A male screw is formed on the screw shaft portion 55. As a result, the nut 31 can be screwed to the screw shaft portion 55.

In this configuration, the harness connection terminal 9 is press-fitted into the first hole 43 by a predetermined tool with the screw shaft 55 inserted into the through hole 41 from the first hole 43 side. At this time, the protrusion 53 bites into the second conductor 35 around the opening of the first hole 43. With the flange portion 51 in contact with the second conductor 35, the press-fitting of the harness connection terminal 9 into the through hole 41 is completed. As a result, the harness connection terminal 9 is in the press-fitting state shown in FIGS. 1, 3 and 5.

In this press-fitting state, the protrusion 53 of the harness connection terminal 9 strongly contacts and couples with the inner wall of the first hole 43. Therefore, mechanical fixing and electrical connection can be realized between the harness connection terminal 9 and the second conductor 35. Further, since the star-shaped protrusion 53 bites into the second conductor 35, it is possible to prevent the harness connection terminal 9 from rotating about the axis.

Due to the press fitting of the harness connection terminal 9, burrs may be generated around the through hole 41 in the second conductor 35. This burr is generated so as to project in the direction in which the harness connection terminal 9 is press-fitted.

However, in the present embodiment, the through hole 41 is formed as a stepped hole, and the press-fitting direction of the harness connection terminal 9 is a direction from the small-diameter first hole portion 43 to the large-sized second hole portion 45. In other words, a ring-shaped recessed portion (step portion 59) is formed from the surface 63 of the second conductor 35 around the root portion where the harness connection terminal 9 protrudes from the second conductor 35. This recessed portion corresponds to the second hole portion 45.

Therefore, even when burrs are generated, as shown in FIG. 5, the starting point of the burrs 61 can be not the surface 63 of the second conductor 35 but the stepped portion 59 recessed from the surface 63. Therefore, the burr 61 can be accommodated in the space 47 corresponding to the second hole 45. As a result, it is possible to prevent the burr 61 from protruding from the surface 63 of the second conductor 35.

In the press-fitting structure 1 of the present embodiment, when the thickness (length in the vertical direction) of the shunt resistance 15 is 2 mm or more and 2.5 mm or less, the depth of the second hole portion 45 (upper and lower) is increased. The length in the direction) is preferably 0.8 mm or more and 1.5 mm or less. According to this configuration, when a burr 61 is generated, the burr 61 can be reliably accommodated in the space 47.

Therefore, when the terminal 27 of the harness 7 is assembled to the harness connection terminal 9 by using the nut 31 after press-fitting the harness connection terminal 9, a burr 61 is formed between the surface 63 of the second conductor 35 and the terminal 27 of the harness 7. Intervention can be prevented. Therefore, it is possible to prevent a gap from being formed between the second conductor 35 and the terminal 27 of the harness 7, and to electrically and satisfactorily connect the two. Further, since it is possible to prevent the burr 61 from getting caught in the screw joint portion and insufficiently tightening the nut 31, it is possible to avoid loosening of the nut 31.

As described above, the press-fitting structure 1 of the present embodiment includes a shunt resistor 15 and a harness connection terminal 9. A through hole 41 is formed in the shunt resistor 15. The harness connection terminal 9 is press-fitted into the through hole 41 from one axial side (lower side) of the through hole 41 toward the other side (upper side), and protrudes from the shunt resistor 15 toward the other side. The through hole 41 is composed of a first hole portion 43 and a second hole portion 45. The first hole portion 43 is coupled to the harness connection terminal 9 by the press fitting. The second hole portion 45 is arranged adjacent to the first hole portion 43 on the side (upper side) where the harness connection terminal 9 protrudes from the shunt resistor 15. The hole diameter D2 of the second hole 45 is larger than the hole diameter D1 of the first hole 43.

As a result, even if a burr 61 is generated near the press-fitting portion of the shunt resistor 15 due to the press-fitting of the harness connection terminal 9, the burr 61 can be accommodated in the space 47 corresponding to the second hole portion 45. .. Therefore, when the terminal 27 of the harness 7 is attached to the shunt resistor 15 via the harness connection terminal 9, it is possible to prevent the burr 61 from interposing between the shunt resistor 15 and the terminal 27. As a result, a good electrical connection between the two can be realized.

Further, in the press-fitting structure 1 of the present embodiment, the first hole portion 43 is open to one side surface of the shunt resistor 15. The second hole portion 45 is opened in the shunt resistor 15 on the surface opposite to the opening of the first hole portion 43.

Thereby, a simple configuration of the through hole 41 can be realized.

Further, the battery state detection device 3 of the present embodiment includes the above-mentioned press-fitting structure 1. The battery state detection device 3 further includes a post connection terminal 5, a harness connection terminal 9, a shunt resistor 15, a circuit board 17, a connector 11, and a casing 13. The post connection terminal 5 is connected to the battery post. The harness connection terminal 9 is connected to the harness 7. The shunt resistor 15 is connected to each of the post connection terminal 5 and the harness connection terminal 9. The circuit board 17 is connected to a shunt resistor. The connector 11 is connected to the circuit board 17. A circuit board 17 is provided on the casing 13.

As a result, it is possible to obtain the battery state detection device 3 capable of ensuring a good electrical connection with respect to the shunt resistor 15.

Although the preferred embodiment of the present invention has been described above, the above configuration can be changed as follows, for example.

The shapes of the first hole portion 43 and the second hole portion 45 are arbitrary, and can be formed into a polygonal shape instead of, for example, a circular shape. At least one of the first hole portion 43 and the second hole portion 45 may be formed in a tapered shape. The second hole portion 45 is preferably formed so as to surround the entire circumference of the harness connection terminal 9.

The shape of the protrusion 53 can also be changed. Instead of making the protrusion 53 into a star shape, it can be made into a polygonal shape or a circular shape. The shape of the flange portion 51 is also arbitrary, and may be formed in a rectangular shape, for example.

The orientation of the press-fit structure 1 is arbitrary. The harness connection terminal 9 can be arranged upside down or horizontally as shown in FIG. 3, for example.

In the above embodiment, the press-fitting structure 1 is applied to the battery state detection device 3, but it can also be applied to other devices.

In view of the above teachings, it is clear that the present invention can take many modified and modified forms. Therefore, it should be understood that the present invention may be practiced in a manner other than that described herein, within the scope of the appended claims.

1 Press-fit structure 3 Battery status detector 5 Post connection terminal 7 Harness 9 Harness connection terminal (press-fit member)
11 Connector 13 Casing 15 Shunt resistor (plate-shaped member)
17 Circuit board 41 Through hole 43 1st hole 45 2nd hole D1 1st hole diameter D2 2nd hole diameter

Claims (3)

A plate-shaped member on which a through hole is formed and
A press-fitting member that is press-fitted into the through-hole from one side in the axial direction toward the other side and projects from the plate-shaped member toward the other side.
With
The through hole is
The first hole portion that is coupled to the press-fitting member by the press-fitting,
A second hole portion in which the press-fitting member is arranged adjacent to the side protruding from the plate-shaped member with respect to the first hole portion and has a hole diameter larger than the hole diameter of the first hole portion.
A press-fitting structure characterized by being provided with. The press-fitting structure according to claim 1.
The first hole is opened on one side of the plate-shaped member.
The second hole portion is a press-fitting structure characterized in that the plate-shaped member is opened on a surface opposite to the opening of the first hole portion. A battery state detection device having the press-fitting structure according to claim 1 or 2.
The post connection terminal connected to the battery post and
The harness connection terminal connected to the harness and
A shunt resistor connected to each of the post connection terminal and the harness connection terminal,
The circuit board connected to the shunt resistor and
The connector connected to the circuit board and
The casing on which the circuit board is provided and
Further prepare
A battery state detecting device, wherein the shunt resistor is the plate-shaped member, and the harness connecting terminal is the press-fitting member.

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