JP5169464B2 - Current measuring device and current measuring method - Google Patents

Description

  The present invention relates to a current measuring device and a current measuring method for measuring a current flowing through a conductive part by detecting a magnetic flux generated by the current.

As a conventional magnetoelectric conversion element type current sensor that detects the magnetic flux generated by the current flowing through the conductive part and measures the current, the connecting member that electrically connects the battery post and the harness has a current density higher than that of other regions. It is known to increase the magnetic flux density acting on the sensor chip of the current sensor and improve the sensitivity of the current sensor by providing a high narrow area (see Patent Document 1 below).
JP 2006-244831 A

  However, in the above-described conventional technology, in order to improve the sensitivity of the current sensor, a configuration in which a region having a higher current density than other regions is provided by reducing the cross-sectional area or the like. In a region higher than this region, there is a problem that Joule heat, which is the product of the resistance and the square of the current value, increases, resulting in a large power loss in the connecting member and a decrease in current measurement accuracy.

  Therefore, an object of the present invention is to improve the measurement accuracy of the current flowing through the conductive part.

The present invention is a current measuring device in which a magnetic flux detection unit for detecting a magnetic flux generated by a current flowing through a conductive part is arranged inside a bent part provided in the conductive part , wherein the conductive part is in the vicinity of a corner of a battery. A battery post that protrudes upward through the lid member of the battery and a battery terminal that is connected to the battery post and extends toward the corner, wherein the bent portion includes the battery post. And a current detection means including the magnetic flux detection unit arranged and fixed in a gap formed between the battery terminal and the lid member of the battery. Features.

According to the present invention, the magnetic flux detecting unit disposed on the bending inner side of the bent portion, the magnetic flux generated by the current flowing near one end of the bent portion and the magnetic flux generated by the current flowing near the other end of the bent portion , by detect the magnetic flux density to be detected becomes high, it is possible to increase the measurement accuracy of the current flowing through the conductive portion.
Further, in the present invention, since the current detection means is arranged and fixed in the gap between the battery terminal and the lid member, the originally wasted space (gap) is effectively used, and the component Layout is improved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  Fig.1 (a) is a front view which shows a part of battery 1 of the motor vehicle provided with the current measuring device concerning the 1st Embodiment of this invention, FIG.1 (b) is AA of Fig.1 (a). It is sectional drawing. FIG. 2 is a perspective view showing a part of the battery 1 described above. FIG. 1 is a simplified diagram with respect to FIG.

  As shown in FIG. 1A, the battery post 3 is provided on the battery 1 so as to protrude upward from the inside of the battery 1 containing the electrolyte solution through the upper lid member 5. The battery terminal 7 is connected to the terminal connection portion 3a with the portion as the terminal connection portion 3a.

  The two battery posts 3 are provided on the positive side and the negative side as shown in FIG. 2, but in FIG. 2, the battery terminal 7 is connected to only one battery post 3 and the other battery post 3 is connected. It is assumed that the battery terminal 7 is not connected to the post 3.

  Here, the battery terminal 7 has an annular holding portion 7a that is fixedly held by a bolt or the like in a state in which the terminal connection portion 3a is inserted, and extends in a horizontal direction substantially perpendicular to the battery post 3 from the holding portion 7a. A harness connecting portion 7b to which the harness 9 is connected.

  The battery post 3, the battery terminal 7 and the wire harness 9 constitute a conductive part, and the connection part 11 between the battery post 3 and the battery terminal 7 constitutes a bent part provided in the conductive part.

  Here, the battery post 3 is positioned near the corner of the rectangular parallelepiped battery 1, and the battery terminal 7 extends toward the corner near the battery terminal 7 as shown in FIG. A gap 13 is formed between the member 5 and the member 5. A current sensor 15 as current detection means is disposed in the gap 13, and the current sensor 15 is fixed to the lid member 5 or the battery terminal 7.

  The above-described current sensor 15 includes a sensor unit 17 including a Hall element or an anisotropic magnetoresistive element as a magnetic flux detection unit having a magnetoelectric conversion element. The sensor unit 17 includes a sensor unit 17 illustrated in FIG. As shown, an external connection connector 19 is connected.

  That is, in the present embodiment, the sensor portion 17 of the current sensor 15 is arranged inside the bent portion of the connection portion 11 that is a bent portion.

  According to the current measuring device having such a configuration, as shown in FIG. 3, for example, when the current I flows from the battery 1 toward the terminal connection portion 3 a that protrudes outside from the battery 1, the terminal connection portion 3 a When a magnetic flux φp is generated in the surroundings and the current I flows toward the wire harness 9 through the battery terminal 7, a magnetic flux φh is also generated around the harness connecting portion 7 b and the wire harness 9.

  These magnetic fluxes φp and φh act on the sensor unit 17 so that the sensor unit 17 converts the magnetic fluxes φp and φh subjected to these actions into currents and processes the converted output signals by a processing circuit (not shown). And measure the current value.

  As described above, in the present embodiment, the current sensor 15 is arranged inside the bent portion 11 of the connection portion 11 between the battery post 3 and the battery terminal 7, so that the sensor portion 17 can generate the magnetic flux φp generated around the terminal connection portion 3a. And the magnetic flux φh generated around the harness connecting portion 7b and the wire harness 9 are affected, so that the magnetic flux density subjected to the action is increased, and therefore the sensitivity as a current sensor is improved and the current measurement accuracy is increased. be able to.

  In this embodiment, since the current sensor 15 having the sensor portion 17 is simply disposed inside the bent portion of the connection portion 11, the Joule heat is large as in the case where a region having a higher current density than other regions is provided. Therefore, a measurement error due to a temperature change caused by an increase in Joule heat can be suppressed small.

  Further, when the current sensor 15 has a function as a temperature sensor for detecting the temperature of the battery 1 by using the temperature characteristic change of the sensor unit 17, the influence of Joule heat is small as described above. The temperature detection error can be suppressed to a small level, and the current sensor 15 is disposed on the upper part of the lid member 5 of the battery 1, so that the temperature measurement accuracy of the battery 1 is improved.

  Furthermore, in this embodiment, it is not necessary to provide a dedicated current detection part as the conductive part, and since the battery post 3 and the battery terminal 7 are only arranged on the bent inner side of the connection part 11, the cost reduction can be achieved. .

  Further, in the present embodiment, the current sensor 15 having the sensor portion 17 is simply disposed inside the bent portion of the connection portion 11, so that the current sensor having a conventional configuration is attached to a connecting member in a region where the current density is higher than other regions. Compared to the above, downsizing can be achieved, and the mountability is also improved.

  In addition, since the conductive portion including the battery post 3 and the battery terminal 7 becomes a magnetic shield against the sensor portion 17 of the current sensor 15, it is caused by a change in magnetic flux outside the conductive portion as viewed from the sensor portion 17. The measurement error of the current sensor 15 can be kept small.

  In the present embodiment, the current sensor 15 is disposed in the gap 13 formed between the battery terminal 7 and the lid member 5 and is fixed to the lid member 5 or the battery terminal 7. Thus, the layout of the parts is improved by effectively using the space (gap 13).

  By the way, in recent years, as a measure for increasing the global average temperature, there has been an increasing demand for improvement in fuel consumption for the purpose of reducing the carbon dioxide emissions of automobiles. As one of the countermeasures, the fuel consumption can be reduced by controlling the charging and discharging of the battery based on the information of the current measured by the current sensor, but the current sensor as in the present embodiment described above. By improving the sensitivity of 15, the fuel efficiency improvement effect can be further expanded.

FIG. 4A is a plan view of a current measuring device according to a first reference example of the present invention, and FIG. 4B is a cross-sectional view taken along the line BB in FIG. This reference example is an example in which a wire harness 21 for an automobile is used as a conductive portion. The wire harness 21 includes an arc-shaped bent portion 21a. A first portion 21b is continuous with one end portion 21a1 of the bent portion 21a, and a second portion is provided with the other end portion 21a2 of the bent portion 21a. 21c is continuous.

  The first part 21b and the second part 21c extend linearly in a direction substantially perpendicular to each other, and each end (not shown) opposite to the bent part 21a is connected to an electrical component (not shown) via a connector or the like. The Such a bent portion 21a of the wire harness 21 is used for connecting each end of the first and second portions 21b, 21c opposite to the bent portion 21a to the above-described electric components, or with other components. In this case, the bent portion 21a is connected to the first and second portions 21b and 21c in the vicinity of both end portions 21a1 and 21a2 of the bent portion 21a via the fixtures 23 and 25. The current sensor 15 in a state of being disposed inside the bend is attached.

  As shown in FIG. 4B, which shows a cross-sectional shape of the fixture 25, the fixtures 23 and 25 are annular wire holding portions 23 a and 25 a that hold the wire harness 21 so as to surround the periphery, and wire holding portions 23 a and 25 a. One end is integrated with the inside of the bent portion 21a, and the other end is provided with connection portions 23b and 25b connected and fixed to the current sensor 15.

  According to the current measuring device having such a configuration, when the current I flows to the first portion 21b of the wire harness 21 toward the bent portion 21a, the current measuring device near the boundary between the bent portion 21a and the first portion 21b. Magnetic flux generated in the periphery acts on the sensor portion 17 of the current sensor 15, and magnetic flux generated in the vicinity of the boundary portion between the bent portion 21 a and the second portion 21 c acts on the sensor portion 17 of the current sensor 15.

  As a result, the current sensor 15 has a higher magnetic flux density to be acted on as in the first embodiment, and thus the sensitivity as the current sensor is improved and the current measurement accuracy can be increased.

In the present reference example , the end portions of the first and second portions 21b and 21c opposite to the bent portion 21a are connected to the electrical components, respectively, or for securing clearance with other components. In addition, since the bent portion 21a is formed and the bent portion 21a is used, it is not necessary to provide a dedicated current detection portion as a conductive portion, and the dedicated conductive portion and the wire harness 21 are connected to each other. This eliminates the need for connecting parts to do so, thus reducing costs.

Furthermore, in the present reference example , the wire harness 21 that constitutes the conductive portion covers the internal electric wire with the external covering portion, so that a dedicated member for ensuring waterproofness is unnecessary, and the cost is reduced. A reduction can be achieved.

  In addition, since the bent portion 21a has an arc shape, and the sensor unit 17 serving as a magnetic flux detection unit is disposed inside the arc shape, the magnetic flux generated by the current flowing in the arc shape also acts on the sensor unit 17. As a result, the magnetic flux density is further increased, and the sensitivity as a current sensor can be further improved.

  Furthermore, since the current sensor 15 having the sensor portion 17 disposed inside the bent portion 21a is attached to the wire harness 21 via the fixtures 23 and 25, the positional relationship of the sensor portion 17 with respect to the bent portion 21a is appropriately set. The current sensor 15 can be attached in the secured state.

  In addition, the fixtures 23 and 25 are good also as a structure provided with the fixing tool 26 as a fixing means which fixes the wire harness 21 to the wiring position of this wire harness 21. FIG. In this case, the fixtures 23 and 25 have both a function of fixing the wire harness 21 in the routing position and a function of attaching the current sensor 15 to the wire harness 21, and each function is individually provided. Compared with the case where the provided fixtures are provided separately, the number of parts can be reduced and the mounting workability is also improved.

FIG. 5A is a plan view of a current measuring apparatus according to a second reference example of the present invention, and FIG. 5B is a cross-sectional view taken along the line CC in FIG. In this reference example , a bent portion 27a is provided on the bus bar 27 as a conductive portion in the same manner as the wire harness 21 of FIG. 4, and the first portion 27b is provided at one end portion 27a1 of the bent portion 27a. A second portion 27c continues to the other end portion 27a2 of 27a, and the first portion 27b and the second portion 27c extend linearly in a direction substantially perpendicular to each other.

Then, the current sensor 15 is attached to the first portion 27b in the vicinity of one end portion 27a1 of the bent portion 27a through the attachment tool 29. Sensor portion 17 of the time the current sensor 15, as in the implementation form and reference example described above positioned in the bent inner side of the bent portion 2 7 a, and the first reference example as well as the sensor unit 17, It arrange | positions inside the circular arc shape of the bending part 27a.

Therefore, also in the second reference example , the current I flows from the first portion 27b of the bus bar 27 to the second portion 27c via the bent portion 27a, and thus the bent portion 27a and the first portion 27b. And the magnetic flux generated around the boundary between the bent portion 27a and the second portion 27c act on the sensor portion 17 of the current sensor 15, respectively, and further the bent portion since the magnetic flux generated around 27a also acts on the sensor unit 17, current sensor 15, as in the implementation form and reference example described above, the higher the magnetic flux density subjected to the action, thus the sensitivity of the current sensor This improves the current measurement accuracy.

In the second reference example, as in the first reference example, further increase the magnetic flux density is so acts on the magnetic flux also the sensor unit 17 caused by the current flowing through the arc-shaped portions of the bent portion 27a in an arc shape, the current The sensitivity as a sensor is further improved, and the current sensor 15 is attached to the bus bar 27 via the attachment 29, so that the current sensor 15 is properly secured in the positional relationship of the sensor part 17 with respect to the bent part 27a. Can be attached.

In each of the first and second reference examples described above, by forming the bent portions 21a and 27a in a coil shape, a large amount of magnetic flux is generated in the bent portions 21a and 27a due to the current flowing through the coiled portions. Thus, it is possible to further increase the magnetic flux density that acts on the sensor portion 17 disposed inside the bent portions 21a and 27a.

Further, the magnetic flux detecting unit comprising a sensor section 17 of the current sensor 15, the magnetic flux may be a core current sensor having a core portion for converging, but in implementation embodiment and reference example described above, the sensor unit 17 acts Since the magnetic flux density received is high, a coreless current sensor may be used.

(A) is a front view which shows a part of battery of the motor vehicle provided with the electric current measurement apparatus concerning the 1st Embodiment of this invention, (b) is AA sectional drawing of (a). It is a perspective view which shows a part of battery of FIG. It is explanatory drawing which shows the generation | occurrence | production state of the magnetic flux in the electric current measurement apparatus of FIG. (A) is a top view of the electric current measurement apparatus concerning the 1st reference example of this invention, (b) is BB sectional drawing of (a). (A) is a top view of the electric current measurement apparatus concerning the 2nd reference example of this invention, (b) is CC sectional drawing of (a).

Explanation of symbols

1 Battery 3 Battery post (conductive part)
7 Battery terminal (conductive part)
9 Wire harness (conductive part)
11 Connection between battery post and battery terminal (bent part of conductive part)
13 Clearance between battery terminal and battery body 15 Current sensor (current detection means)
17 Sensor section (magnetic flux detection section) of current sensor
21 Wire harness (conductive part)
21a Bent part of wire harness 21a1 One end part of bent part 21a2 Other end part of bent part 21b First part of wire harness 21c Second part of wire harness 23, 25, 29 Fixing tool 26 Fixing tool (fixing) means)
27 Bus bar (conductive part)
27a Bent part of bus bar 27a1 One end part of bent part 27a2 Other end part of bent part 27b First part of bus bar 27c Second part of bus bar

Claims (2)

The current flowing through the conductive portion, when measuring by detecting the magnetic flux generated by the current, said conductive portion bent portions provided in, and arranged a magnetic flux detector for detecting the magnetic flux in the bent inner side of the bent portion current A measuring device,
The conductive portion includes a battery post that is located near the corner of the battery and protrudes upward through the lid member of the battery, and a battery terminal that is connected to the battery post and extends toward the corner. The bent portion includes a connection portion between the battery post and the battery terminal;
A current measuring device comprising: a current detecting means including the magnetic flux detecting unit arranged and fixed in a gap formed between the battery terminal and the lid member of the battery . A current measurement method for detecting a magnetic flux by a magnetic flux detection unit disposed inside a bent portion provided in the conductive portion when measuring a current flowing through the conductive portion by detecting a magnetic flux generated by the current. ,
The conductive portion includes a battery post that is located near the corner of the battery and protrudes upward through the lid member of the battery, and a battery terminal that is connected to the battery post and extends toward the corner. The bent portion includes a connection portion between the battery post and the battery terminal;
By the magnetic flux detection part of the current detection means arranged in the gap formed between the battery terminal and the battery lid member inside the bent part of the bent part, the current flowing near one end of the bent part resulting magnetic flux and the magnetic flux generated by the current flowing through the other end portion near the bent portion, that it detects the current measuring method characterized by measuring the current through the conductive portion.

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