JP2011003694A - Shunt resistor, and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shunt resistor improved in detection accuracy of current, in a resistor used for large current detection of a low resistance value ≤1 mΩ.SOLUTION: The shunt resistor includes: a resistive body formed of a resistive alloy plate material 11; a pair of main electrodes 12a, 12b fixed at both ends of the resistive body and each formed of a metal plate material having predetermined thickness, the pair of main electrodes having facing surfaces A, B facing each other; and detection electrodes 14a, 14b projecting from the facing surfaces. The resistive alloy plate material 11 and the metal plate material 20 are prepared; the pair of main electrodes 12a, 12b and connection parts 13a, 13b for connecting the pair of main electrodes to each other are formed on both sides of the metal plate material and at the center part of the metal plate material, respectively; the detection electrodes 14a, 14b projecting from the surfaces A, B facing each other of the pair of main electrodes in the vertical direction thereof are formed; both ends of the resistive alloy plate material are jointed to the pair of main electrodes to straddle the pair of main electrodes; and the connection parts are cut and removed, whereby the resistor can be manufactured.

Description

  The present invention relates to a shunt resistor for current detection, and more particularly to a shunt resistor for large current applications in which a main electrode made of a metal plate is joined to both ends of a resistor made of a resistance alloy plate.

  Conventionally, a shunt resistor having the above-described structure (see, for example, Patent Document 1) has been widely used for large current detection applications such as monitoring charging / discharging current of a vehicle-mounted battery. These shunt resistors are provided with a resistor made of a resistance alloy plate and a main electrode made of a copper material fixed to both ends thereof, and a detection electrode section is provided at an appropriate location of the main electrode, for example, an aluminum electrode there. The voltage generated at both ends of the resistor is detected by connecting the wires.

  Such a shunt resistor has excellent detection accuracy of a large current, a small temperature drift, no excessive heat generation even when a large current is applied, a low resistance value of 1 mΩ or less, etc. Is required. In order to detect the voltage generated in such a low-resistance resistor with high accuracy and small temperature drift, the voltage generated at both ends of the resistor is detected in addition to the type of the resistance alloy material, the shape and structure of the resistor. The position of the terminal is largely related.

  That is, if the position of the terminal on the main electrode is on the main electrode, the voltage generated at both ends of the resistor can be detected, but the internal resistance of the main electrode cannot be ignored with a resistor having a low resistance value of 1 mΩ or less, In the case of the detection terminal for fixing the wire to the main electrode, the fixing position is not clearly determined, so that there is a variation in the mounting position of the wire and there is a problem that the detection accuracy is not stable.

JP 2003-173905 A

  The present invention has been made based on the above-described circumstances, and an object thereof is to provide a shunt resistor with improved current detection accuracy in a resistor for large current detection having a low resistance value of 1 mΩ or less. .

  The shunt resistor of the present invention includes a resistor made of a resistance alloy plate, a pair of main electrodes made of a metal plate having a predetermined thickness fixed to both ends of the resistor, and the pair of main electrodes facing each other. And a detection electrode protruding from the opposing surface.

  Further, the shunt resistor manufacturing method of the present invention comprises preparing a resistance alloy plate having a predetermined thickness and width and a metal plate having a predetermined thickness and width, and a pair of main electrodes on both sides of the metal plate. A connecting portion for connecting the pair of main electrodes to a central portion of the metal plate material, and a detection electrode projecting in a vertical direction from mutually opposing surfaces of the pair of main electrodes, Both ends of the resistance alloy sheet are joined to the pair of main electrodes so as to straddle, and the connecting portion is cut and removed.

(A) is a perspective view which shows the shunt resistor of 1st Example of this invention, (b) is sectional drawing along the CC line, (c) is the top view. (A)-(f) is a perspective view which shows the manufacturing process of the shunt resistor of 1st Example. It is a perspective view which shows the shunt resistor of 2nd Example of this invention. It is a perspective view which shows the shunt resistor of 3rd Example of this invention. (A)-(f) is a perspective view which shows the manufacturing process of the shunt resistor of 3rd Example.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 5. In addition, in each figure, the same code | symbol is attached | subjected and demonstrated to the same or equivalent member or element.

  As shown in FIG. 1, this shunt resistor has a pair of main electrodes 12a made of a metal plate having a predetermined thickness and width at both ends of a resistor 11 made of a resistance alloy plate having a predetermined thickness and width. 12b is fixed by pressure welding or the like. Here, a plate material such as a Cu—Mn alloy, a Ni—Cr alloy, or a Cu—Ni alloy is used for the resistance alloy plate material, and a Cu material is suitable for the metal plate material constituting the main electrode.

  The pair of main electrodes 12a and 12b have opposing surfaces A and B facing each other, and include detection electrodes 14a and 14b protruding in the vertical direction from the opposing surfaces. The detection electrodes 14a and 14b and the main electrodes 12a and 12b are integrated, and the detection electrodes 14a and 14b are part of the main electrodes 12a and 12b. The detection electrodes 14a and 14b have an opening H, and wires 15a and 15b, which are voltage detection terminals, are inserted into the opening H and fixed by welding or the like.

  The upper surfaces of the detection electrodes 14a and 14b are flush with the upper surfaces (rear surfaces) of the main electrodes 12a and 12b, and the lower surfaces of the detection electrodes 14a and 14b are separated from the lower surface (front surface) to which the resistor 11 of the main electrode is joined. . The detection electrodes 14a and 14b are provided on the central axis CC in the current direction of the pair of main electrodes 12a and 12b.

  By providing the detection electrodes 14a and 14b which are tabs integrated with the main electrodes 12a and 12b, the fixing positions of the wires 15a and 15b become clear. For this reason, the fall of the detection accuracy by the dispersion | variation in the fixed position of wire 15a, 15b can be suppressed. Then, by integrating the detection electrodes 14a and 14b with the main electrodes 12a and 12b, characteristics are stabilized as compared to a structure in which they are fixed separately. Moreover, since mechanical strength is also high, it can suppress that a main electrode deform | transforms at the time of wire adhering.

  The detection electrodes 14a and 14b protrude from the opposing surfaces A and B of the main electrodes 12a and 12b, so that the voltage generated at both ends of the resistor 11 can be accurately detected. That is, in a resistor having a low resistance value of 1 mΩ or less, the voltage distribution caused by the resistance component inside the main electrode cannot be ignored. When this voltage distribution is taken into consideration, the fixed position of the voltage detection terminals (wires 15a and 15b) is It is clear that the resistance value increases and the TCR increases as the distance from the opposing surfaces A and B of the main electrode increases.

  Therefore, it is ideal to detect the voltage on the opposing surfaces A and B of the main electrode, and this is possible with the above configuration. Incidentally, when fixing the conventional voltage detection terminals (wires 15a, 15b) to the main electrodes 12a, 12b by welding or the like, it is practically difficult to arrange the wires 15a, 15b on the facing surfaces A, B, It is impossible to detect the voltages on the opposing surfaces A and B that do not include the voltage distribution caused by the resistance component inside the main electrode.

  The main electrodes 12a and 12b are provided with through holes 16a and 16b for bolt fastening. Depending on the method of fixing to the base or the like, the through hole may not be formed, a screw groove for tightening and fixing with a bolt may be formed in the through hole, or the bolt may be formed to protrude from the metal plate 20. Various changes are possible.

  Next, the manufacturing method of this shunt resistor is demonstrated with reference to FIG. First, as shown in FIG. 2A, a metal plate 20 having a predetermined thickness and width is prepared. The outline dimensions of the metal plate 20 are, for example, about 80 mm in length, about 20 mm in width, and about 3 mm in thickness.

  Next, as shown in FIG. 2B, the connecting portions 13a and 13b and the detection electrodes 14a and 14b are formed in the intermediate portion of the metal plate material 20 by a method such as pressing or cutting. That is, a pair of main electrodes 12a and 12b having a predetermined thickness and width and a pair of connecting portions 13a and 13b for connecting the main electrodes are formed at both ends of the metal plate member 20, and the opposing surface A between the main electrodes is further formed. , B are formed with detection electrodes 14a, 14b protruding from the facing surfaces A, B.

  The connecting portions 13a and 13b and the detection electrodes 14a and 14b are formed by grinding an intermediate portion of the metal plate material 20 along the thickness direction from the surface, grinding a certain distance from the surface in the thickness direction to form a concave surface, and then connecting by a press. The remaining portions 13a and 13b and the detection electrodes 14a and 14b are left and other portions are punched and removed. The back surfaces of the coupling portions 13a and 13b are flush with the back surfaces of the pair of main electrodes 12a and 12b, and the side surfaces of the coupling portions 13a and 13b are flush with the side surfaces of the pair of main electrodes 12a and 12b. There is no. The connecting portions 13a and 13b may be formed by press working.

  Next, as shown in FIG. 2C, recesses 17a and 17b for positioning the resistance alloy plate material (resistor) 11 are formed by grinding or the like. Then, as shown in FIG. 2 (d), the resistance alloy plate material 11 is positioned and placed so as to fit into the recesses 17a and 17b, and both ends of the resistance alloy plate material 11 are placed on the surfaces of the main electrodes 12a and 12b. Join to straddle. For joining the resistance alloy plate 11 and the main electrodes 12a and 12b, various methods such as electron beam welding, pulse energization joining, thermocompression bonding, cold pressure welding, resistance welding, soldering by soldering, etc. can be applied. From the viewpoint of stability of characteristics such as the bonding state and resistance value, it is preferable to use diffusion bonding using pulse current bonding or thermocompression bonding.

  FIG. 2 (e) is a reverse view. The connecting portions 13a and 13b for connecting the main electrodes 12a and 12b of the metal plate 20 on the back surface side are disposed at positions spaced from the surface of the main electrodes 12a and 12b in the thickness direction, and the connecting portions 13a and 13b are cut. To remove. A grinder or nipper is used for cutting.

  As a result, as shown in FIG. 2 (f), the main electrodes 12a and 12b are electrically and mechanically separated, and the main electrodes 12a and 12b are respectively provided with detection electrodes 14a and 14b integrated therewith. The detection electrodes 14a and 14b are appropriately provided with openings H for connecting wires. In addition, you may provide the opening H in the step of FIG.2 (b).

  In this shunt resistor, as described above, both the main electrodes 12a and 12b are connected to each other by the connecting portions 13a and 13b, and both ends of the resistance alloy plate 11 are pressed against the surfaces of both the main electrodes 12a and 12b. Join. For this reason, the distance between electrodes does not shift at the time of joining, and a shunt resistor can be manufactured in a state where high parallelism and dimensional accuracy of the interval are maintained by using metal working techniques such as press working and grinding.

  Accordingly, by processing the width and thickness of the resistance alloy plate 11 with high accuracy, the resistance value of the resistor is determined by the inter-electrode length, width and thickness of the resistor. By detecting this voltage, a highly accurate resistance value can be obtained. Accordingly, for example, it is possible to stably produce a shunt resistor having almost no variation in characteristics without adjusting the resistance value with respect to the target resistance value of 0.1 mΩ.

  FIG. 3 shows a shunt resistor according to a second embodiment of the present invention. The difference from the first embodiment is that the detection electrodes 14c and 14d protrude from the opposing surfaces A and B of the main electrodes 12a and 12b and are bent vertically upward. Accordingly, the voltage detection terminals (wires 15a and 15b, see FIG. 1) can be crimped to the detection electrodes 14c and 14d using a sleeve or the like. When the through hole is formed in the substrate and the through hole is configured as a voltage detection pattern, the detection electrode can be inserted into the through hole and soldered.

  This shunt resistor is configured so that the detection electrodes 14a and 14b protruding from the opposing surfaces A and B of the main electrodes 12a and 12b are vertically upward (with the opposing surface) in the manufacturing process of the first embodiment (FIG. 2 (f)). It can be manufactured by folding in parallel.

  FIG. 4 shows a shunt resistor according to a third embodiment of the present invention. The difference between the first embodiment and the second embodiment is that the detection electrodes 14e and 14f protrude from the end portions in the width direction of the opposing surfaces A and B of the main electrodes 12a and 12b and are bent vertically to the side. It is in. Accordingly, the voltage detection terminals (wires 15a and 15b, see FIG. 1) can be crimped to the detection electrodes 14e and 14f using a sleeve or the like in the same manner as described above. When the through hole is formed in the substrate and the through hole is configured as a voltage detection pattern, the detection electrode can be inserted into the through hole and soldered.

  FIG. 5 shows an example of the manufacturing process of this shunt resistor. As shown in FIG. 5A, the preparation of a metal plate 20 having a predetermined thickness and width is the same as in the first embodiment. Next, as shown in FIG.5 (b), a recessed part is formed in the center part of the metal plate material 20, and the through-hole O is formed by press work or grinding, leaving both ends. Thereby, a pair of main electrodes 12a and 12b are connected to both ends of the metal plate member 20, and a pair of connecting portions 13a and 13b for connecting the main electrodes to each other along the lower surface and the side surface of the metal plate member 20, and the connecting portions 13a and 13b. Is formed so that the upper surface thereof is positioned below the main electrodes 12a and 12b. The connecting portion 13b serves as detection electrodes 14e and 14f as will be described later.

  Next, as shown in FIG. 5 (c), dents 17a and 17b for positioning the resistance alloy plate 11 are formed on the upper surfaces of the main electrodes 12a and 12b by pressing or grinding. And as shown in FIG.5 (d), the resistance alloy board | plate material 11 is aligned and mounted so that it may fit in the positioning dents 17a and 17b, and the resistance alloy board | plate material 11 is mounted on the upper surface of main electrode 12a, 12b. Join.

  FIG. 5 (e) is a diagram in which this is reversed. The connecting portions 13a and 13b for connecting the main electrodes 12a and 12b of the metal plate material 20 on the back surface side are arranged at positions spaced from the surface of the main electrodes 12a and 12b in the thickness direction, and the entire connecting portion 13a is cut off. The connecting portion 13b is removed by cutting only its central portion. Then, both sides of the connecting portion 13b become detection electrodes 14e and 14f, which are bent to the sides of the main electrodes 12a and 12b in parallel to the opposing surfaces A and B.

  As a result, as shown in FIG. 5 (f), the main electrodes 12a and 12b are electrically and mechanically separated, and the main electrodes 12a and 12b are provided with detection electrodes 14e and 14f integrated therewith. Similar to the first embodiment, the detection electrodes 14e and 14f may be appropriately provided with openings H for wire connection.

  The detection electrodes 14e and 14f may be kept straight without being bent to the side of the main electrodes 12a and 12b. Thereby, it becomes a structure similar to 1st Example.

  Although one embodiment of the present invention has been described so far, it is needless to say that the present invention is not limited to the above-described embodiment, and may be implemented in various forms within the scope of the technical idea.

  INDUSTRIAL APPLICABILITY The present invention can be suitably used for a shunt resistor in which a main electrode made of a metal plate material is disposed at both opposing ends of a resistance alloy plate material, particularly a shunt resistor for large current applications.

Claims (11)

A resistor made of a resistance alloy plate,
A pair of main electrodes made of a metal plate having a predetermined thickness fixed to both ends of the resistor;
A shunt resistor comprising: a pair of main electrodes having opposed surfaces facing each other, and a detection electrode protruding from the opposed surfaces.   The shunt resistor according to claim 1, wherein the detection electrode is a part of the main electrode and is integral with the main electrode.   The shunt resistor according to claim 1, wherein the detection electrode is provided on a central axis in a current direction of the pair of main electrodes.   The detection electrode protrudes in the vertical direction from the facing surface, one surface of the detection electrode is flush with the one surface of the main electrode, and the other surface of the detection electrode is the other surface to which the resistor of the main electrode is joined. The shunt resistor of claim 1, wherein the shunt resistor is spaced apart from   The shunt resistor according to claim 4, wherein the detection electrode is bent in parallel to the facing surface. Preparing a resistance alloy sheet having a predetermined thickness and width, and a metal sheet having a predetermined thickness and width;
A pair of main electrodes on both sides of the metal plate, a connecting portion for connecting the pair of main electrodes to a central portion of the metal plate, and a detection electrode protruding in the vertical direction from the mutually opposing surfaces of the pair of main electrodes And form the
Bonding both ends of the resistance alloy plate material to the pair of main electrodes so as to straddle the pair of main electrodes,
A method of manufacturing a shunt resistor, wherein the connecting portion is cut and removed.   7. The shunt resistor according to claim 6, wherein one surface of the detection electrode is flush with one surface of the main electrode, and the other surface of the detection electrode is separated from the other surface to which the resistor of the main electrode is joined. Manufacturing method.   The shunt resistor manufacturing method according to claim 6, wherein the detection electrode is provided on a central axis in a current direction of the pair of main electrodes.   Furthermore, the manufacturing method of the shunt resistor of Claim 8 which bends the said detection electrode in parallel with the said opposing surface.   The method for manufacturing a shunt resistor according to claim 6, wherein the detection electrode is provided at an end in a width direction of the facing surface. Furthermore, the manufacturing method of the shunt resistor of Claim 10 which bend | folds the said detection electrode to the side of the said main electrode in parallel with the said opposing surface.

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