JP5018846B2 - Current detector - Google Patents

Description

  The present invention relates to a current detection device that is mounted on a passenger car, a truck, or the like and detects a charge / discharge current of a battery.

  2. Description of the Related Art Conventionally, a voltage drop type current measuring device that detects a charge / discharge current of a battery based on a voltage drop amount between two points of a bus bar that is attached to a battery terminal and functions as a shunt resistor is known (for example, Patent Documents). 1). This voltage drop type current measuring device is arranged on the side surface of the battery, and two through holes are provided at both ends in the longitudinal direction. One through hole (upper side) is for fastening with a bolt to a conductive metal fitting extending from the positive terminal of the battery. The other through hole (lower side) is for fastening with a bolt to a power supply electric wire to the starter.

Japanese Patent Laying-Open No. 2005-188945 (page 5-10, FIG. 1-10)

  By the way, since the voltage drop type current measuring device disclosed in Patent Document 1 is mounted on the side surface of the battery, depending on the mounting state of other components, work when electrically connecting through through holes at both ends through bolts There was a problem that the nature was bad. In particular, there is a case where there is not enough room in the engine room to widen the vehicle interior space, or there is a case where sufficient space on the side surface of the battery cannot be secured due to the layout in the engine room, and improvement in workability is desired.

  The present invention has been created in view of such a point, and an object of the present invention is to provide a current detection device capable of improving workability when attached to a battery.

  In order to solve the above-described problem, the current detection device of the present invention is a current detection device that detects a current flowing through a harness through a terminal of a battery, and is fixed to the wiring on the battery side to be electrically connected. A first fixing portion, a second fixing portion in which a harness is fixed and electrical connection is made, a resistor inserted between the first and second fixing portions, and a current-carrying direction of the resistor The circuit board on which the current detection circuit for detecting the current flowing through the resistor based on the potential difference at two locations along the line is mounted, and the resistor and the circuit board are arranged between the first and second fixing portions. Each of a first mounting surface to which the battery-side wiring is attached in the first fixing portion and a second mounting surface to which the harness is attached in the second fixing portion are parallel to the upper surface of the battery. The first and With placing the second mounting surface are both above the battery, and than the first mounting surface to place the second mounting surface at a low position.

  By arranging both the first mounting surface and the second mounting surface above the battery and making them both parallel to the upper surface of the battery, wiring on the first fixed portion and the battery terminal side in the vicinity of the upper surface of the battery Since the fixing work and the fixing work of the second fixing part and the harness can be performed, the workability when the current detection device is attached to the battery can be improved. Further, by providing a step on the two mounting surfaces, it is possible to prevent the tool from coming into contact with the opposite fixing portion when the fixing operation is performed on the respective mounting surfaces. Furthermore, since there are steps on the two mounting surfaces, it is possible to prevent water, mud, electrolytic solution, and the like due to water from being collected between the two mounting surfaces without any gaps. Further, by lowering the position of the second fixing portion, it is possible to prevent the vehicle body second fixing portion from coming into contact with the vehicle body.

  The first mounting surface described above is preferably at the same height as the battery terminal, and the second mounting surface is preferably lower than the battery terminal. In particular, it is desirable that the above-described second mounting surface is at a position lower than the upper surface of the battery. As a result, when attaching the harness to the second fixing portion, the tool stops against the side of the battery even if the tool is turned too much, so the tool is not connected to the other battery terminal (the terminal on the side to which the first fixing portion is connected). It is possible to avoid a short circuit due to contact with the other terminal.

  In addition, the case described above is desirably arranged along the side surface of the battery closest to the battery terminal to which the first fixing portion is connected. Thereby, even when the current detection device rotates around the first fixing portion, it is possible to prevent the case from rotating further in a state where the case is in contact with the side surface of the battery. And the battery terminal side can be prevented from loosening.

  Moreover, it is desirable that the above-described resistor has a U-shape that is folded back inside the case. Thereby, the space | interval of a 1st fixing | fixed part and a 2nd fixing | fixed part can be made close, and size reduction of the whole electric current detection apparatus and the effective utilization of the space of a battery side surface can be aimed at.

It is sectional drawing which shows the structure of the electric current detection apparatus of one Embodiment. It is a side view of an electric current detection apparatus. It is a perspective view of an electric current detection apparatus. It is a figure which shows the example of a connection of the specific example of the circuit of an electric current detection apparatus, a battery, etc. FIG.

  Hereinafter, a current detection device according to an embodiment to which the present invention is applied will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view illustrating a configuration of a current detection device according to an embodiment, and illustrates a state where the current detection device is attached to a battery. 2 is a side view of the current detection device, and FIG. 3 is a perspective view of the current detection device.

  As shown in these drawings, the current detection device 100 of this embodiment includes a bus bar 110 as a resistor (shunt resistor) formed using a conductive material, and two locations along the energization direction of the bus bar 110. Electrical connection is made between the circuit board 120 on which the current detection circuit for detecting the current flowing through the bus bar 110 based on the potential difference is mounted, the case 130 housing the bus bar 110 and the circuit board 120, and the circuit board 120. The connector 140 has a plurality of connector terminals 142 exposed inside, and a lid 150 that closes the opening of the recess of the case 130 in which the circuit board 120 is accommodated.

  The bus bar 110 has a U-shape that is folded back inside the case 130, and has one end fixed to the wiring on the battery 200 side to form a first fixing portion 112 that is electrically connected. The other end portion forms the second fixing portion 114 to which the harness is fixed and electrical connection is performed. In the present embodiment, a case 130 having a rectangular parallelepiped shape is arranged so as to be vertically long in the vicinity of the side surface of the battery 200 (the side surface closest to the terminal 202 of the battery 200 to which the current detection device 100 is attached) First and second fixing portions 112 and 114 protrude in the horizontal direction on both sides of the vertically long case 130.

  The first fixing portion 112 has a U-shaped cross section, and a through hole 112A (see FIG. 3) is formed in a part of the U-shaped bottom surface. On the other hand, as shown in FIG. 1, the current detection device 100 is attached to the negative terminal 202 of the battery 200, and a mounting bracket 210 that also serves as a wiring between the negative terminal 202 and the first fixing portion 112 is attached. ing. A bolt 211 projects upward from the end of the mounting bracket 210. In the present embodiment, the bolt 211 of the mounting bracket 210 is inserted into the through hole 112A from the recessed opening side of the first fixing portion 112 having a U-shape, and the fixing portion 112 is tightened with a nut (not shown). As a result, the first fixing portion 112 is fixed to the mounting bracket 210. In this case, the concave bottom surface (lower surface) to which the mounting bracket 210 is attached in the first fixing portion 112 is the mounting surface (first mounting surface) 112B (see FIG. 2).

  The second fixing portion 114 is provided with a through hole in the vicinity of the end portion, and a bolt 115 is inserted into the through hole. On the other hand, a terminal 302 having a through hole is provided at an end portion of the harness 300 electrically connected to the second fixing portion 114, and the second fixing portion 114 is provided in the through hole of the terminal 302. The terminal 302 is fixed to the second fixing portion 114 by inserting the bolt 115 and tightening the terminal 302 with a nut (not shown). In this case, the upper surface to which the terminal 302 is attached in the second fixing portion 114 is the attachment surface (second attachment surface) 114B (see FIG. 2).

  In the present embodiment, the case 130 is formed of a resin material having good insulation and thermal conductivity, for example, PPS (polyphenylene sulfide) resin, and is externally provided as the first fixing portion 112 or the second fixing portion 114. Most of the bus bar 110 excluding the exposed portion is insert-molded with this resin material.

  Next, the positions of the first and second fixing portions 112 and 114 will be described. In the present embodiment, a first mounting surface 112B for mounting the mounting bracket 110 on the battery 200 side in the first fixing portion 112, and a second mounting surface 114B for mounting the terminal 302 of the harness 300 on the second fixing portion 114. Each is set so as to be parallel to the upper surface 200A (FIG. 1) of the battery 200.

  Each of the first and second attachment surfaces 112B and 114B is disposed above the battery 200, and the second attachment surface 114B on the harness 300 side than the first attachment surface 112B on the battery 200 side. Is located at a lower position. Here, “above the battery 200” means in the vicinity of the upper surface 200A of the battery 200. For example, the tip of the bolt 115 provided on the second fixing portion 114 on the lower side is higher than the upper surface 200A of the battery 200. The position of the second mounting surface 114B is determined so as not to be lowered.

  For example, the first mounting surface 112 </ b> B is set to the same height as the terminal 202 of the battery 200. Further, the second mounting surface 114 </ b> B is set at a position lower than the terminal 202 of the battery 200, more specifically at a position lower than the upper surface 200 </ b> A of the battery 200.

  FIG. 4 is a diagram illustrating a specific example of a circuit of the current detection device 100 and a connection example between the battery 200 and the like. As shown in FIG. 4, the circuit board 120 of the current detection device 100 has a differential amplifier 10 connected to both ends of a shunt resistor 100 ′ formed by a part of the bus bar 110, and a positive terminal and a negative terminal of the battery 200. Differential amplifier 12, temperature detection unit 20, current detection processing unit 30, voltage detection processing unit 32, temperature detection processing unit 34, battery state detection unit 36, charge control unit 40, communication input / output unit (communication I / O) / O) 50, 52, a CAN interface (CAN I / F) 60 that transmits and receives data according to the CAN protocol, and a LIN interface (LIN I / F) 62 that transmits and receives data according to the LIN protocol. Yes. One differential amplifier 10 amplifies the voltage across the shunt resistor 100 ′, and the current detection processing unit 30 detects the current flowing through the shunt resistor 100 ′ based on the output voltage of the differential amplifier 10. The differential amplifier 10 and the current detection processing unit 30 constitute a current detection circuit. The other differential amplifier 12 converts the voltage across the battery 200 (battery voltage) to an appropriate level, and the voltage detection processing unit 32 detects the battery voltage based on the output voltage of the differential amplifier 12. The temperature detection unit 20 is configured by a voltage dividing circuit including a resistor and a thermistor. The resistance value of the thermistor changes according to the temperature, and the divided voltage of the voltage dividing circuit changes. The temperature detection processing unit 34 detects the temperature of the current detection device 100 (the temperature of the battery 200) based on the output voltage (divided voltage) of the temperature detection unit 20. The battery state detection unit 36 takes in the detection values of the current detection processing unit 30, the voltage detection processing unit 32, and the temperature detection processing unit 34, and generates a battery state signal. The current detection processing unit 30, voltage detection processing unit 32, temperature detection processing unit 34, and battery state detection unit 36 constitute a state detection sensor 38. The charge control unit 40 controls the power generation state of the vehicular generator (G) 80 based on the battery state signal generated by the battery state detection unit 36. This power generation control is performed by sending an instruction to the power generation control device 82 mounted on the vehicle generator 80 via the communication input / output unit 52 and the LIN interface 62. The battery status signal generated by the battery status detection unit 36 is sent to the vehicle system 70 via the communication input / output unit 50 and the CAN interface 60. The vehicle system 70 performs integrated control on the engine and various electric loads based on the received battery state signal and the like.

  As described above, in the current detection device 100 of the present embodiment, both the first mounting surface 112B and the second mounting surface 114B are disposed above the battery 200, and both of them are parallel to the upper surface 200A of the battery 200. As a result, the battery 200 can be fixed to the first fixing portion 112 and the mounting bracket 210 on the battery terminal side or the harness 300 to the second fixing portion 114 in the vicinity of the upper surface 200A of the battery 200. The workability at the time of attaching the current detection device 100 to 200 can be improved. Further, by providing a step on the two mounting surfaces 112B and 114B, it is possible to prevent the tool from coming into contact with the fixing portion on the opposite side when the mounting surfaces 112B and 114B are fixed. Further, since the two mounting surfaces 112B and 114B have a step (because they are not on the same plane), water, mud, electrolytic solution, etc. due to moisture etc. are prevented from collecting between these two mounting surfaces without any gaps. be able to.

  Further, the first mounting surface 112B is set to the same height as the terminal 202 of the battery 200, and the second mounting surface 114B is positioned lower than the terminal 202 of the battery 200, specifically, the upper surface 200A of the battery 200. When the harness 300 is attached to the second fixing portion 114 because the tool is attached to the second fixing portion 114, the tool hits the side of the battery 200 and stops even if the tool is turned too much. It is possible to avoid a short circuit due to contact with a terminal opposite to 202.

  Further, by arranging a vertically long case 130 in which a part of the bus bar 110 and the circuit board 120 are accommodated along the side surface of the battery 200 closest to the terminal 202, current detection is performed around the first fixing portion 112. Even when the device 100 is rotated, it is possible to prevent the case 130 from rotating further in a state where the case 130 is in contact with the side surface of the battery, so that the first fixing portion 112 and the mounting bracket 210 on the battery side can be fixed. Can be prevented from loosening.

  In addition, by forming the bus bar 110 in a U shape that is folded in the case 130, the distance between the first fixing portion 112 and the second fixing portion 114 can be made closer, and the current detection device 100 as a whole can be reduced in size. Thus, the space on the side of the battery can be effectively used.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the embodiment described above, the current detection device is connected to the negative terminal 202 of the battery 200, but the current detection device 100 may be connected to the positive terminal.

  In the above-described embodiment, the case 130 of the current detection device 100 is disposed along the side surface closest to the terminal 202 of the battery 200, but depending on the length of the mounting bracket 210 and the first fixing portion 112, Since the distance to the current detection device 100 is allowed to be increased to some extent, the current detection device 100 may be mounted so that the case 130 is disposed along the other side surface of the battery 200.

  In the above-described embodiment, the opening of the concave portion of the case 130 in which the circuit board 120 is accommodated is covered with the lid 150. However, the entire concave portion including the circuit board 120 is filled with a filler such as an epoxy resin. You may make it cover.

  In the above-described embodiment, the resistor (shunt resistor) formed integrally with the bus bar 110 is used. However, a range including at least two locations for detecting a potential difference is replaced with a resistor separate from the bus bar 110. You may do it.

  As described above, according to the present invention, the fixing work of the first fixing part 112 and the wiring on the battery terminal side and the fixing work of the second fixing part 114 and the harness 300 can be performed near the upper surface 200A of the battery 200. Therefore, workability when attaching the current detection device 100 to the battery 200 can be improved. Further, by providing a step on the two mounting surfaces 112B and 114B, it is possible to prevent the tool from coming into contact with the fixing portion on the opposite side when the fixing operation is performed on the respective mounting surfaces. Furthermore, since there are steps on the two mounting surfaces, it is possible to prevent water, mud, electrolytic solution, and the like due to water from being collected between the two mounting surfaces without any gaps.

DESCRIPTION OF SYMBOLS 100 Current detection apparatus 110 Bus bar 112 1st fixing | fixed part 112A Through-hole 112B 1st attachment surface 114 2nd fixing | fixed part 114B 2nd attachment surface 115, 211 Bolt 120 Circuit board 130 Case 140 Connector 142 Connector terminal 150 Lid 200 Battery 202, 302 Terminal 210 Mounting bracket 300 Harness

Claims (5)

A current detection device for detecting a current flowing through a harness through a terminal of a battery,
A first fixing portion fixed to the wiring on the battery side and electrically connected;
A second fixing portion where the harness is fixed and electrical connection is made;
A resistor inserted between the first and second fixing portions;
A circuit board on which a current detection circuit for detecting a current flowing through the resistor based on a potential difference between two locations along the energization direction of the resistor is mounted;
A case that is disposed between the first and second fixing portions and that accommodates the resistor and the circuit board;
Each of a first attachment surface for attaching the wiring on the battery side in the first fixing portion and a second attachment surface for attaching the harness in the second fixing portion are parallel to the upper surface of the battery. And
A current detecting device, wherein both the first and second mounting surfaces are disposed above the battery, and the second mounting surface is disposed at a lower position than the first mounting surface. In claim 1,
The first mounting surface is at the same height as the battery terminals;
The current detection device, wherein the second mounting surface is located at a position lower than a terminal of the battery. In claim 2,
The current detection device, wherein the second mounting surface is located at a position lower than an upper surface of the battery. In claim 1,
The current detection device according to claim 1, wherein the case is disposed along a side surface of the battery closest to a terminal of the battery to which the first fixing portion is connected. In any one of Claims 1-4,
The current detection device according to claim 1, wherein the resistor has a U-shape folded in the case.

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