Shunt resistor, manufacturing method thereof, and current detection device

Abstract

To provide a shunt resistor having a simple structure and capable of reducing a resistance temperature coefficient.SOLUTION: A shunt resistor 1 includes a resistor 5, and a pair of electrodes 6 and 7 connected to both ends 5a and 5b of the resistor 5 in a first direction, and the shunt resistor 1 includes a protrusion 11 formed on the side surface 1a of the shunt resistor 1, which is a surface parallel to the first direction, and a recess 12 formed on the side surface 1b of the shunt resistor 1 and extending in the same direction as the protrusion 11, and the protrusion 11 has a portion of the resistor 5 and a portion of the pair of electrodes 6 and 7, and the recess 12 has the side surface 5d of the resistor 5 parallel to the first direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a shunt resistor and a method for manufacturing the shunt resistor, and also to a current detection device including the shunt resistor. [Background technology]

[0002] Shunt resistors are widely used for current detection. Such shunt resistors include a resistive body and electrodes joined to both ends of the resistive body. In general, the resistive body is made of a resistive alloy such as a copper-nickel alloy, a copper-manganese alloy, an iron-chromium alloy, or a nickel-chromium alloy, and the electrodes are made of a highly conductive metal such as copper. The electrodes are provided with a voltage detection section, and a conductor (e.g., an aluminum wire) is connected to the voltage detection section to detect the voltage generated at both ends of the resistive body.

[0003] An example of a conventional shunt resistor is shown in Figures 24 and 25. As shown in Figures 24 and 25, shunt resistor 100 includes resistor element 105 made of a plate-shaped resistive alloy having a predetermined thickness and width, and a pair of electrodes 106, 107 made of a highly conductive metal connected to both ends of resistor element 105. Bolt holes 108, 109 for fixing shunt resistor 100 with screws or the like are formed in electrodes 106, 107, respectively.

[0004] The shunt resistor 100 further includes voltage detection units 120, 121 for measuring the voltage of the resistor 105. In the example shown in Fig. 24, the voltage detection units 120, 121 are formed integrally with the electrodes 106, 107, respectively. The voltage detection units 120, 121 extend from the side surfaces of the electrodes 106, 107 in the width direction of the electrodes 106, 107. The voltage detection units 120, 121 are disposed in the vicinity of the resistor 105.

[0005] 25, the voltage detection units 120 and 121 are pins extending perpendicularly from the surfaces of the electrodes 106 and 107. The voltage detection units 120 and 121 are disposed in the vicinity of the resistor 105. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2017-5204 A [Patent Document 2] JP 2007-329421 A Summary of the Invention [Problem to be solved by the invention]

[0007] In a shunt resistor, the characteristic of the temperature coefficient of resistance (TCR) is important in order to enable current detection under conditions where the influence of temperature fluctuations is small. The temperature coefficient of resistance is an index that indicates the rate of change in resistance value due to temperature. Therefore, an object of the present invention is to provide a shunt resistor that has a simple structure and can reduce the temperature coefficient of resistance. Another object of the present invention is to provide a method for manufacturing such a shunt resistor and a current detection device equipped with such a shunt resistor. [Means for solving the problem]

[0008] In one aspect, a plate-shaped shunt resistor for use in current detection is provided, comprising a resistor and a pair of electrodes connected to both ends of the resistor in a first direction, the shunt resistor having a protrusion formed on a first side of the shunt resistor, which is a surface parallel to the first direction, and a recess formed on a second side of the shunt resistor, which is the surface opposite to the first side, and extending in the same direction as the protrusion, the protrusion having a part of the resistor and a part of the pair of electrodes, and the recess having a side of the resistor parallel to the first direction.

[0009] In one embodiment, the length of the recess in a second direction perpendicular to the first direction is the same as the length of the protrusion in the second direction. In one embodiment, the protrusion includes a pair of voltage detection portions connected to both ends of the resistor in the first direction. In one embodiment, the protrusion and the recess have a rectangular shape.

[0010] In one aspect, a method for manufacturing a shunt resistor having a resistor and a pair of electrodes connected to both ends of the resistor is provided, comprising the steps of: preparing a long shunt resistor base material with a pair of electrodes connected to both ends of the resistor in a first direction; cutting the shunt resistor base material in the first direction into a convex shape to form a protrusion of the first shunt resistor having a part of the resistor of the first shunt resistor and a part of the pair of electrodes of the first shunt resistor; cutting the shunt resistor base material in the first direction into a convex shape at a distance from the protrusion to form a recess of the first shunt resistor and a protrusion of a second shunt resistor extending in the same direction as the protrusion; and cutting the shunt resistor base material in the first direction into a convex shape to form a recess of the first shunt resistor and a protrusion of a second shunt resistor extending in the same direction as the protrusion, and the protrusion of the second shunt resistor having a part of the resistor of the second shunt resistor and a part of the pair of electrodes of the second shunt resistor.

[0011] In one aspect, a current detection device is provided, comprising the above-mentioned shunt resistor and a current detection circuit board having a voltage signal wiring that transmits a voltage signal from the shunt resistor, the voltage signal wiring being electrically connected to a protrusion of the shunt resistor.

[0012] In one embodiment, the current detection circuit board further includes a voltage terminal pad, and the voltage terminal pad is connected to the protruding portion and the voltage signal wiring. In one embodiment, the current detection device further includes an output terminal for outputting a voltage signal from the shunt resistor, the output terminal being attached to a recess in the shunt resistor. Effect of the Invention

[0013] With a simple structure that simply involves forming a protrusion having part of the resistor and parts of a pair of electrodes on a first side of the shunt resistor, and forming a recess having a side of the resistor parallel to the first direction on a second side of the shunt resistor, it is possible to reduce the resistance temperature coefficient of the shunt resistor while maintaining the desired resistance value. [Brief description of the drawings]

[0014] [Figure 1] FIG. 1 is a perspective view illustrating one embodiment of a shunt resistor. [Diagram 2] FIG. 2 is a plan view of the shunt resistor shown in FIG. [Diagram 3] FIG. [Figure 4] FIG. 1 is a perspective view showing an embodiment of a current detection device including a shunt resistor. [Diagram 5] 2 is a perspective view showing the current detection device when the case of the voltage output device is removed. FIG. [Figure 6] 4 is a schematic diagram showing a state in which a voltage detection terminal is provided in a voltage detection section; FIG. [Figure 7] 1 is a graph showing the rate of change in resistance value of a shunt resistor due to temperature change. [Figure 8] FIG. 13 is a plan view of an embodiment of a shunt resistor without a recess. [Figure 9] 13 is a graph showing the relationship between the length of the protrusion in the second direction and the rate of change in resistance value of the shunt resistor. [Figure 10] 11 is a graph showing the relationship between the length of a protrusion of a shunt resistor and the rate of change in resistance value of the shunt resistor. [Figure 11] 1 is a graph showing a rate of change in resistance value of a shunt resistor. [Figure 12] FIG. 13 is a perspective view showing another embodiment of a shunt resistor. [Figure 13] FIG. 13 is an enlarged view of the protrusion of FIG. 12. [Figure 14] 1A to 1C are diagrams illustrating an example of a manufacturing process for a shunt resistor. [Figure 15] FIG. 13 is a schematic diagram showing yet another embodiment of the shunt resistor. [Figure 16] FIG. 13 is a schematic diagram showing yet another embodiment of the shunt resistor. [Figure 17] FIG. 13 is a schematic diagram showing yet another embodiment of the shunt resistor. [Figure 18] FIG. 13 is a schematic diagram showing yet another embodiment of the shunt resistor. [Figure 19] 10A to 10C are schematic diagrams showing another embodiment of a method for manufacturing a shunt resistor. [Figure 20] 10A to 10C are schematic diagrams showing another embodiment of a method for manufacturing a shunt resistor. [Figure 21] FIG. 13 is a perspective view showing yet another embodiment of a shunt resistor. [Figure 22] FIG. 22 is a side view of FIG. 21. [Diagram 23] 4 is a schematic diagram showing a state in which a voltage detection terminal is provided in a voltage detection section; FIG. [Figure 24] FIG. 1 is a diagram showing an example of a conventional shunt resistor. [Diagram 25] FIG. 1 is a diagram showing an example of a conventional shunt resistor. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings described below, the same or corresponding components are denoted by the same reference numerals, and duplicated descriptions will be omitted. In the multiple embodiments described below, the configuration of one embodiment that is not particularly described is the same as the other embodiments, so duplicated descriptions will be omitted.

[0016] Fig. 1 is a perspective view showing one embodiment of a shunt resistor 1, and Fig. 2 is a plan view of the shunt resistor 1 shown in Fig. 1. As shown in Figs. 1 and 2, the shunt resistor 1 includes a resistor 5 made of a resistive alloy plate material having a predetermined thickness and width, and a pair of electrodes 6, 7 made of a highly conductive metal connected to both ends (i.e., both connection surfaces) 5a, 5b of the resistor 5 in a first direction. The electrode 6 has a contact surface 6a that contacts one end (one connection surface) 5a of the resistor 5, and the electrode 7 has a contact surface 7a that contacts the other end (the other connection surface) 5b of the resistor 5. The electrodes 6, 7 are formed with bolt holes 8, 9 for fixing the shunt resistor 1 with screws or the like, respectively.

[0017] The first direction is the length direction of the resistor 5, which corresponds to the length direction of the shunt resistor 1. The length direction of the shunt resistor 1 is the direction in which the electrode 6, resistor 5, and electrode 7 are arranged in this order. A direction perpendicular to the first direction is the second direction. The second direction is the width direction of the shunt resistor 1. As shown in Figures 1 and 2, the electrodes 6 and 7 have the same structure and are arranged symmetrically with respect to the resistor 5.

[0018] Both ends 5a, 5b of the resistor 5 are connected (joined) to the electrodes 6, 7, respectively, by means of welding (for example, electron beam welding, laser beam welding, or brazing). An example of the material of the resistor 5 is a low resistance alloy material such as a Cu-Mn alloy. An example of the material of the electrodes 6, 7 is copper (Cu).

[0019] The shunt resistor 1 has a protrusion 11 formed on a side surface 1a of the shunt resistor 1 and a recess 12 formed on a side surface 1b of the shunt resistor 1. The protrusion 11 extends outward from the side surface 1a, and the recess 12 extends inward (towards the center of the shunt resistor 1) from the side surface 1b. Both the protrusion 11 and the recess 12 extend in the same direction (the second direction). The protrusion 11 and the recess 12 have a rectangular shape when viewed from above (when viewed from a direction perpendicular to both the first direction and the second direction).

[0020] Side surface 1a is a surface of shunt resistor 1 parallel to the first direction, and includes side surface 6c of electrode 6 and side surface 7c of electrode 7. Side surface 1b is a surface of shunt resistor 1 parallel to the first direction, and is the surface opposite side surface 1a. Side surface 1b includes side surface 6b of electrode 6 and side surface 7b of electrode 7. Side surfaces 6b, 7b are surfaces parallel to side surfaces 6c, 7c.

[0021] 3 is an enlarged view of the protrusion 11 and the recess 12. The protrusion 11 has a part of the resistor 5 and parts of the electrodes 6 and 7. Specifically, the protrusion 11 has a portion 14 which is a part of the resistor 5, and voltage detection portions 20 and 21 for measuring the voltage generated at both ends 5a and 5b of the resistor 5. The length of the portion 14 in the second direction is represented by a length t1 (the length t1 of the protrusion 11 in the second direction) which is the distance from the side surfaces 6c and 7c of the electrodes 6 and 7 to the side surface 5c of the resistor 5.

[0022] The voltage detection units 20 and 21 are parts of the electrodes 6 and 7, respectively. That is, the electrode 6 has the voltage detection unit 20, and the electrode 7 has the voltage detection unit 21. The voltage detection unit 20 extends outward from the side surface 6c of the electrode 6, and the voltage detection unit 21 extends outward from the side surface 7c of the electrode 7. The voltage detection units 20 and 21 are connected to both ends 5a and 5b of the resistor 5, respectively. The voltage detection units 20 and 21 are disposed symmetrically with respect to the portion 14. The length of the voltage detection units 20 and 21 in the second direction is also represented by a length t1.

[0023] The recess 12 has a side surface 5d of the resistor 5 parallel to the first direction. Specifically, in this embodiment, the side surface 12c of the recess 12 in the first direction (see FIG. 2) is composed of the side surface 6d of the electrode 6, the side surface 5d of the resistor 5, and the side surface 7d of the electrode 7. In this embodiment, the width W1 of the protrusion 11 (the length of the protrusion 11 in the first direction) and the width W2 of the recess 12 (the length of the recess 12 in the first direction) are the same, and the length t1 of the protrusion 11 in the second direction (i.e., the width direction of the shunt resistor 1) and the length t2 of the recess 12 in the second direction are the same. The position of the protrusion 11 in the first direction and the position of the recess 12 in the first direction are the same. That is, the side surface 11a of the protrusion 11 is arranged on an extension line of the side surface 12a of the recess 12, and the side surface 11b of the protrusion 11 is arranged on an extension line of the side surface 12b of the recess 12.

[0024] 4 is a perspective view showing an embodiment of a current detection device 30 including a shunt resistor 1. The current detection device 30 further includes a voltage output device 31 that outputs the voltage of the resistor 5 (the voltage generated across both ends 5a, 5b of the resistor 5) to the outside. The voltage output device 31 is connected to the shunt resistor 1. The voltage output device 31 includes a non-conductive case 32 that covers the resistor 5, and an output terminal 35 (output connector 35) for outputting a voltage signal (the voltage of the resistor 5) from the shunt resistor 1. The output connector 35 includes a first terminal, a second terminal, and a ground terminal, which are not shown.

[0025] Fig. 5 is a perspective view showing the current detection device 30 when the case 32 of the voltage output device 31 is removed. As shown in Fig. 5, the voltage output device 31 further includes a current detection circuit board 34. The current detection circuit board 34 has voltage signal wires 46 and 47 that transmit a voltage signal (the voltage of the resistor 5) from the shunt resistor 1 to the output terminal 35, and a ground wire 50. The current detection circuit board 34 is disposed on the shunt resistor 1, and the output terminal 35 is attached to the recess 12.

[0026] The current detection circuit board 34 further has voltage terminal pads 36, 37 (copper foil portions 36, 37). One end of the voltage signal wiring 46 is connected to the voltage terminal pad 36, and the other end is connected to a first terminal of the output connector 35. One end of the voltage signal wiring 47 is connected to the voltage terminal pad 37, and the other end is connected to a second terminal of the output connector 35. The voltage signal wirings 46, 47 are bent from the second direction (see FIG. 2) to the first direction (see FIG. 2) above the protruding portion 11. One end of the ground wiring 50 is connected to the voltage terminal pad 36, and the other end is connected to the ground terminal of the output connector 35. The voltage signal wirings 46, 47, the ground wiring 50, and the voltage terminal pads 36, 37 are formed of a highly conductive metal (copper in this embodiment).

[0027] The voltage terminal pad 36 is connected to the voltage detection position 16 (see FIG. 3) of the voltage detection unit 20 of the protruding portion 11 via an internal wiring (not shown) of the current detection circuit board 34. Similarly, the voltage terminal pad 37 is connected to the voltage detection position 17 (see FIG. 3) of the voltage detection unit 21 of the protruding portion 11 via an internal wiring (not shown). That is, the voltage signal wirings 46 and 47 are electrically connected to the voltage detection units 20 and 21 of the protruding portion 11, respectively. The internal wiring and the voltage detection units 20 and 21 are connected by a method such as soldering. An operator connects a cable having a connector that fits into the output terminal 35 to measure the voltage generated at both ends 5a and 5b of the resistor 5. With this configuration, the voltage of the resistor 5 can be easily measured. In one embodiment, an operational amplifier (amplifier) ​​for amplifying the voltage signal from the shunt resistor 1, an A / D converter, and / or a temperature sensor may be mounted on the current detection circuit board 34.

[0028] In one embodiment, as shown in FIG. 6, voltage detection terminals 38, 39 may be provided on the voltage detection units 20, 21, respectively. The voltage detection terminals 38, 39 are conductive pins extending vertically from the surfaces of the voltage detection units 20, 21, respectively. Specifically, the voltage detection terminals 38, 39 are connected to the voltage detection positions 16, 17 of the voltage detection units 20, 21, respectively, by a technique such as soldering. The voltage generated across the resistor 5 is measured by connecting a conductor (e.g., aluminum wire) to each of the voltage detection terminals 38, 39, or by inserting the voltage detection terminals 38, 39 into through holes formed in a circuit board and electrically connecting them to wiring formed on the circuit board. With this configuration, the voltage of the resistor 5 can be measured with a simple configuration.

[0029] Fig. 7 is a graph showing the rate of change in resistance of the shunt resistor 1 due to temperature change. The horizontal axis of Fig. 7 represents the temperature of the shunt resistor 1, and the vertical axis of Fig. 7 represents the rate of change in resistance of the shunt resistor 1. The curve shown by the solid line represents the rate of change in resistance of the shunt resistor 1 of this embodiment, and the curve shown by the dotted line represents the rate of change in resistance of a conventional shunt resistor (shunt resistor 100 shown in Fig. 24). Fig. 7 shows the results when a copper-manganese based alloy was used as the resistor 5.

[0030] As is clear from a comparison of the fluctuation range of the resistance change rate of the shunt resistor 1 of this embodiment with that of a conventional shunt resistor, the shunt resistor 1 of this embodiment can reduce the fluctuation range of the resistance change rate due to temperature change. That is, the result of Fig. 7 shows that the shunt resistor 1 can reduce the temperature coefficient of resistance (TCR). By forming the protrusion 11 having a part of the resistor 5 and a part of the electrodes 6 and 7 as described above, the equipotential lines are distorted, and as a result, the temperature coefficient of resistance of the shunt resistor 1 can be reduced.

[0031] FIG. 8 is a plan view showing an embodiment of a shunt resistor 200 that does not have a recess 12. The configuration of the shunt resistor 200 is the same as that of the shunt resistor 1, except that the shunt resistor 200 does not have a recess 12. That is, the shunt resistor 200 includes a resistor 205 corresponding to the resistor 5 of the shunt resistor 1, and a pair of electrodes 206 and 207 connected to both ends of the resistor 205. The electrodes 206 and 207 correspond to the electrodes 6 and 7 of the shunt resistor 1. The shunt resistor 200 includes a protrusion 211 corresponding to the protrusion 11 of the shunt resistor 1, and the protrusion 211 includes a part of the resistor 205 and a part of the electrodes 206 and 207. The protrusion 211 includes voltage detection parts 220 and 221 that are part of the electrodes 206 and 207 that are arranged symmetrically with respect to the resistor 205.

[0032] Fig. 9 is a graph showing the relationship between the length t3 of the protrusion 211 in the second direction and the rate of change in resistance of the shunt resistor 200. Fig. 9 shows the results when a copper-manganese alloy is used as the resistor 205 for the shape of the shunt resistor shown in Fig. 8. The vertical axis of Fig. 9 shows the rate of change in resistance when the temperature of the shunt resistor 200 rises from 25°C to 100°C. The results of Fig. 9 show that the rate of change in resistance of the shunt resistor 200 depends on the length t3. More specifically, the rate of change in resistance decreases as the length t3 increases.

[0033] FIG. 10 is a graph showing the relationship between the length t1 of the protrusion 11 of the shunt resistor 1 and the rate of change in resistance of the shunt resistor 1. FIG. 10 shows the results when a copper-manganese alloy is used as the resistor 5 for the shape of the shunt resistor shown in FIG. 2. The length t2 of the recess 12 is the same as the length t1. The vertical axis of FIG. 10 shows the rate of change in resistance when the temperature of the shunt resistor 1 rises from 25° C. to 100° C. The results of FIG. 10, like the results of FIG. 9, show that the rate of change in resistance of the shunt resistor 1 depends on the length t1, and the larger the length t1, the lower the rate of change in resistance. For example, when the length t1 is 2 mm, the rate of change in resistance of the shunt resistor 1 is about 0%.

[0034] 10, the rate at which the resistance change rate of the shunt resistor 1 decreases is similar to the rate at which the resistance change rate of the shunt resistor 200 shown in FIG 9 decreases. That is, the results in FIG 10 show that the temperature-dependent resistance change rate of the shunt resistor 1 depends on the length t1 of the protrusion 11, not on the recess 12. Therefore, the results in FIG 10 show that the resistance temperature coefficient of the shunt resistor 1 can be corrected and reduced by adjusting the length t1.

[0035] FIG. 11 is a graph showing the rate of change in resistance of each of the shunt resistor 1 and the shunt resistor 200. FIG. 11 shows the rate of change in resistance of the shunt resistor 1, 200 due to changes in the lengths t1, t3 of the protrusions 11, 211 at a predetermined temperature (constant temperature). The length t2 of the recess 12 is the same as the length t1. The result of FIG. 11 shows that in the shunt resistor 200 without the recess 12, the resistance value changes greatly depending on the length t3 of the protrusion 211. For example, the resistance value of the shunt resistor 200 when the length t3 is 1.5 mm is about 8% lower than the resistance value when the length t3 is 0 mm. This is because the length of the resistor 205 in the second direction increases by forming the protrusion 211, and the resistance value of the resistor 205 changes.

[0036] 11, in the shunt resistor 1 having the recess 12, the change in the resistance value of the shunt resistor 1 due to the change in length t1 is suppressed. This is because the length of the resistor 5 in the second direction is kept constant by forming the recess 12 having the side surface 5d of the resistor 5. In other words, by forming the recess 12, the change in the resistance value of the shunt resistor 1 due to the formation of the protrusion 11 can be suppressed.

[0037] Therefore, a desired TCR can be achieved while maintaining a desired resistance value by adjusting the length t1 of the protrusion 11 and the length t2 of the recess 12 of the shunt resistor 1 according to the size and shape of the shunt resistor 1. Therefore, according to this embodiment, with a simple structure in which the protrusion 11 having a part of the resistor 5 and parts of the electrodes 6 and 7 is formed on the side surface 1a of the shunt resistor 1, and the recess 12 having the side surface 5d of the resistor 5 is formed on the side surface 1b of the shunt resistor 1, the resistance temperature coefficient of the shunt resistor 1 can be reduced while maintaining a desired resistance value.

[0038] FIG. 12 is a perspective view showing another embodiment of the shunt resistor 1, and FIG. 13 is an enlarged view of the protrusion 11 in FIG. 12. The configuration of this embodiment that is not particularly described is the same as the embodiment described with reference to FIG. 1 to FIG. 3, so the overlapping description will be omitted. The resistor 5 of this embodiment has a notch 25. The notch 25 extends parallel to the end faces 5a, 5b (in the second direction shown in FIG. 2). The notch 25 has a slit shape that extends linearly. The notch 25 is formed on the side surface 5c of the resistor 5, and extends linearly from the side surface 5c toward the inside of the shunt resistor 1 (the center of the shunt resistor 1).

[0039] By forming such a cutout portion 25 in the resistor 5, the resistance value of the shunt resistor can be adjusted, and in addition, the TCR of the shunt resistor 1 can be finely adjusted. Specifically, the TCR can be increased by narrowing the width W3 of the cutout portion 25 in the first direction and increasing the length t4 in the second direction. The current detection device 30 described with reference to Figs. 4 and 5 and the voltage detection terminals 38, 39 described with reference to Fig. 6 can also be applied to this embodiment.

[0040] Next, a description will be given of a manufacturing method of the shunt resistor 1. Figures 14(a) to 14(f) are diagrams showing an example of a manufacturing process of the shunt resistor 1. In Figures 14(a) to 14(f), the bolt holes 8 and 9 are omitted.

[0041] First, as shown in FIG. 14(a), a long (strip-shaped) shunt resistor base material 60 (metal plate material) is prepared in a state in which electrodes 6, 7 are connected to both ends of a resistor 5 in a first direction. Next, as shown in FIG. 14(b), the shunt resistor base material 60 is cut in a direction in which the electrodes 6, resistor 5, and electrodes 7 are aligned (i.e., the first direction). Specifically, the shunt resistor base material 60 is cut in the first direction into a convex shape. The convex shape corresponds to the protrusion 11 of the shunt resistor 1. By cutting the shunt resistor base material 60 in the first direction into a convex shape, the side surface 1a and the protrusion 11 of the shunt resistor 1 (first shunt resistor 1A) are formed (FIG. 14(c)).

[0042] Next, as shown in Fig. 14(c), the shunt resistor base material 60 is cut in the first direction into a convex shape, with a gap in the second direction from the protrusion 11 and the side surface 1a, as in Fig. 14(b). As a result, the first shunt resistor 1A is separated from the shunt resistor base material 60, and the side surface 1b of the first shunt resistor 1A, the recess 12 of the first shunt resistor 1A, the protrusion 11 of the other shunt resistor 1 (second shunt resistor 1B), and the side surface 1a of the second shunt resistor 1B are formed (Fig. 14(d)).

[0043] Next, as shown in Figures 14(e) and 14(f), similarly to Figures 14(c) and 14(d), the shunt resistor base material 60 is cut in the first direction into a convex shape, with a gap in the second direction from the protruding portion 11 and side surface 1a of the second shunt resistor 1B. As a result, the second shunt resistor 1B is separated from the shunt resistor base material 60, and the side surface 1b of the second shunt resistor 1B and the recessed portion 12 of the second shunt resistor 1B are formed. A plurality of shunt resistors 1 are manufactured by repeating the steps of Figures 14(c) to 14(f).

[0044] 14(a) to 14(f), the shunt resistor 1 can be manufactured in a simple manner, and the shunt resistor base material 60 can be utilized without waste. As a result, costs can be reduced.

[0045] Figures 15 to 18 are schematic diagrams showing still another embodiment of the shunt resistor 1. The configuration of this embodiment not specifically described is the same as that of the embodiment described with reference to Figures 1 to 3, and therefore the duplicated description will be omitted. In Figures 15 to 18, the bolt holes 8 and 9 are omitted. The current detection device 30 described with reference to Figures 4 and 5 and the voltage detection terminals 38 and 39 described with reference to Figure 6 can also be applied to the embodiment shown in Figures 15 to 18.

[0046] In one embodiment, the side surfaces 11a, 11b of the protrusion 11 and the side surfaces 12a, 12b of the recess 12 may be formed at an angle with respect to the second direction (see FIG. 2) as shown in Fig. 15. In the example shown in Fig. 15, the side surfaces 11a, 11b extend in a direction away from the resistor 5. The side surface 12a is formed parallel to the side surface 11a, and the side surface 12b is formed parallel to the side surface 11b.

[0047] In one embodiment, as shown in Fig. 16, the voltage detection units 20 and 21 may have cutouts 20a and 21a extending from the side surfaces 11a and 11b toward the resistor 5, respectively. Furthermore, in one embodiment, as shown in Fig. 17, the width W2 of the recess 12 may be larger than the width W1 of the protrusion 11, or as shown in Fig. 18, the width W2 may be smaller than the width W1.

[0048] Fig. 19 is a schematic diagram showing another embodiment of a method for manufacturing a shunt resistor 1. As shown in Fig. 19, the shunt resistor 1 may be manufactured by punching out a shunt resistor base material 60 into the outer shape of the shunt resistor 1. As shown in Fig. 20, the shunt resistor 1 of the embodiment shown in Fig. 17 may be manufactured by a method similar to the method described with reference to Fig. 19.

[0049] FIG. 21 is a perspective view showing yet another embodiment of the shunt resistor 1, and FIG. 22 is a side view of FIG. 21. FIG. 22 is a view of the shunt resistor 1 of FIG. 21 as viewed from the direction indicated by the arrow A. As shown in FIG. 21 and FIG. 22, in this embodiment, the thickness of the electrodes 6, 7 is greater than the thickness of the resistor 5. As shown in FIG. 22, the rear surfaces of the electrodes 6, 7 and the rear surface of the resistor 5 are on the same plane, and the surfaces 6e, 7e of the electrodes 6, 7 are higher than the surface 5e of the resistor 5 in the thickness direction of the shunt resistor 1. The thickness direction of the shunt resistor 1 is a direction perpendicular to both the first direction and the second direction.

[0050] In this embodiment, a step 18 is formed by the surface 6e of the electrode 6, the contact surface 6a, and the surface 5e of the resistor 5, and a step 19 is formed by the surface 7e of the electrode 7, the contact surface 7a, and the surface 5e of the resistor 5. A space SP is formed by the steps 18, 19, and the surface 5e.

[0051] According to such a structure of the shunt resistor 1, when a substrate such as the current detection circuit board 34 is placed on the surface of the shunt resistor 1, a gap (space SP) can be formed between the resistor 5 and the substrate. This makes it possible to prevent heat generated by the resistor 5 from being directly transmitted to the substrate. It also becomes possible to arrange wiring for voltage detection (for example, voltage signal wiring 46, 47) in the space SP.

[0052] There is no resistor 5 between the surfaces of the voltage detection units 20 and 21. Therefore, the current flowing through the shunt resistor 1 avoids the surfaces of the voltage detection units 20 and 21, and stable voltage detection can be performed on the surfaces of the voltage detection units 20 and 21 (for example, detection areas 22 and 23 shown by diagonal lines in FIGS. 21 and 22).

[0053] In one embodiment, as shown in FIG. 23, voltage detection terminals 38 and 39 may be provided on the voltage detection units 20 and 21 (for example, on the detection areas 22 and 23), respectively.

[0054] The above-described embodiments have been described for the purpose of enabling a person having ordinary skill in the art to practice the present invention. Various modifications of the above-described embodiments are naturally possible for a person skilled in the art, and the technical idea of ​​the present invention can be applied to other embodiments. Therefore, the present invention is not limited to the described embodiments, but is to be interpreted in the broadest scope according to the technical idea defined by the claims. [Explanation of symbols]

[0055] 1 Shunt resistor 1A 1st shunt resistor 1B Secondary Shunt Resistor 1a,1b side 5 Resistor 5a, 5b both ends (connection surfaces on both sides) 5c,5d side 6,7 electrodes 6a,7a Contact surface 6b,6c,6d Side 7b,7c,7d Side 8,9 Bolt holes 11 Protrusion 11a,11b Side 12 Recess 12a,12b,12c side 14 parts 16,17 Voltage detection position 20, 21 Voltage detection section 20a, 21a Notch 22,23 Detection area 25 Cutout 30 Current detection device 31 Voltage output device 32 cases 34 Current detection circuit board 35 Output terminal 36,37 Voltage terminal pads 38,39 Voltage detection terminal 46,47 Voltage signal wiring 50 Ground wiring 60 Shunt resistor base material 100 Shunt Resistor 105 Resistor 106,107 electrode 108,109 Bolt holes 120,121 Voltage detection unit 200 Shunt Resistor 205 Resistor 206,207 electrode 211 Protrusion 220,221 Voltage detection unit

Claims

1. A plate-shaped shunt resistor used for current detection, A resistor; a pair of electrodes connected to both ends of the resistor in a first direction; The shunt resistor is a protrusion formed on a first side surface of the shunt resistor, the first side surface being a surface parallel to the first direction; a recess formed on a second side surface of the shunt resistor, the second side surface being the opposite side surface of the shunt resistor to the first side surface, and extending in the same direction as the protrusion; the protrusion has a part of the resistor and a part of the pair of electrodes, and includes a voltage detection portion on the part of the pair of electrodes; A shunt resistor, wherein a side surface of the recess parallel to the first direction is composed of a side surface of the resistor and a side surface of the electrode.

2. The shunt resistor according to claim 1 , wherein a length of the recess in a second direction perpendicular to the first direction is the same as a length of the protrusion in the second direction.

3. The shunt resistor according to claim 1 , wherein the protrusion and the recess have a rectangular shape.

4. A method for manufacturing a shunt resistor including a resistor and a pair of electrodes connected to both ends of the resistor, comprising the steps of: preparing a long shunt resistor base material having a pair of electrodes connected to both ends of the resistor in a first direction; cutting the shunt resistor base material in the first direction into a convex shape to form a protruding portion of the first shunt resistor having a part of a resistor body of the first shunt resistor and a part of a pair of electrodes of the first shunt resistor; cutting the shunt resistor base material in the first direction into a convex shape at a distance from the protruding portion to form a concave portion of the first shunt resistor and a protruding portion of the second shunt resistor extending in the same direction as the protruding portion; the protrusion of the second shunt resistor includes a part of a resistor body of the second shunt resistor and a part of a pair of electrodes of the second shunt resistor; A method for manufacturing a shunt resistor, wherein the protrusion has a voltage detection portion on a part of the pair of electrodes.

5. A shunt resistor according to any one of claims 1 to 3; a current detection circuit board having a voltage signal wiring for transmitting a voltage signal from the shunt resistor; A current detection device, wherein the voltage signal wiring is electrically connected to a protrusion of the shunt resistor.

6. The current detection circuit board further includes a voltage terminal pad, The current detection device according to claim 5 , wherein the voltage terminal pad is connected to the protruding portion and the voltage signal wiring.

7. An output terminal for outputting a voltage signal from the shunt resistor is further provided. The current detection device according to claim 5 , wherein the output terminal is attached to a recess of the shunt resistor.

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