Device for measuring electric current

Abstract

Device (100) for measuring electric current, which measures a current flowing between a battery (200) and a wiring harness (300), comprising: a first fastening element (112) which is to be electrically fastened to a terminal (202) of a battery (200); a second fastening element (114) with which the wiring harness (300) can be electrically fastened; a resistor (110) arranged between the first and the second fastening element (112, 114); a circuit board (120) on which a current measuring circuit is arranged, which is suitable for measuring the current flowing through the resistor (110) as a function of the current flowing between the battery (200) and the wiring harness (300) on the basis of the potential difference between two points defined on the current path passing through the resistor (110); and a housing arranged between the first and the second fastening element (112, 114). (130),in which the resistor (110) and the circuit board (120) are arranged, wherein the first fastening element (112) has a first connecting surface (112B) for electrical connection with the terminal (202) of the battery (200) and the second fastening element (114) has a second connecting surface (114B) for electrical connection with the wiring harness (300), and the first and the second connecting surfaces (112B, 114B), when mounted in their position, are oriented such that they are substantially parallel to the upper surface (200A) of the battery (200), and wherein, with respect to the upper surface (200A) of the battery (200), the second connecting surface (114B) is in a lower position than the first connecting surface (112B) when mounted in their position.

Description

BACKGROUND OF THE INVENTION 1. Technical field of the invention

[0001] The present invention generally relates to a device for measuring electric current, intended for installation in motor vehicles, such as passenger cars or trucks, in order to sense or measure the electric current being charged into or discharged from a storage battery installed in the vehicle. 2. State of the art

[0002] The Japanese First Publication of Patents 2005-188945 discloses a voltage-based current measuring device designed to monitor a voltage drop across a busbar connected to a terminal of a storage battery and acting as a parallel resistor, and to determine the current being charged or discharged from the storage battery. The voltage-based current measuring device is mounted on a side face of the battery and has two through-holes: an upper and a lower one, formed at its ends and separated longitudinally. The upper hole is used to attach the voltage-based current measuring device to a conductive strip extending from the positive (+) terminal of the battery by means of a bolt.The lower hole is used to connect the current measuring device, which operates on the basis of a voltage drop, to an electrical line for the power supply of a motor starter by means of a bolt.

[0003] The voltage-based current measuring device has the problem that its ease of installation—inserting and tightening the bolts when attaching it to the side of the battery—is reduced due to the design of other parts. Ensuring sufficient space around the battery's side for mounting the current measuring device can be challenging, especially if the vehicle's engine compartment volume has been reduced to increase passenger space or due to the arrangement of other components within the engine compartment. SUMMARY OF THE INVENTION

[0004] Therefore, a main objective of the invention is to provide an improved design of a current measuring device that is designed to ensure the ability to be mounted on a storage battery, which is installed, for example, in the engine compartment of motor vehicles.

[0005] According to one aspect of the invention, a device for measuring electric current is provided, which measures a current flowing between a battery and a wiring harness. The current-measuring device comprises: (a) a first mounting element to be electrically connected to a terminal of a battery; (b) a second mounting element to which the wiring harness can be electrically connected; (c) a resistor arranged between the first and the second mounting element; (d) a circuit board on which a current-measuring circuit is arranged, which is suitable for measuring the current flowing through the resistor as a function of the current flowing between the battery and the wiring harness, based on the potential difference between two points defined on the current path through the resistor; and (e) a housing arranged between the first and the second mounting element, in which the resistor and the circuit board are arranged.The first mounting element has a first contact surface for electrical connection to the battery terminal. The second mounting element has a second contact surface for electrical connection to the wiring harness. When installed, the first and second contact surfaces are oriented such that they are substantially parallel to an upper surface of the battery. Relative to the upper surface of the battery, the second contact surface is positioned lower than the first contact surface when installed.

[0006] In particular, when the current measuring device is mounted on the battery, the first and second connection surfaces are aligned parallel to the upper surface of the battery, thus facilitating the connection between the first mounting element and the battery, and between the second mounting element and the wiring harness, close to the upper surface of the battery. This improves the feasibility of mounting the current measuring device on the battery.The first and second connection surfaces differ in their level relative to the upper surface of the battery. This prevents a tool used to connect one of the first and second fasteners to an associated bracket or connector from interfering with the other first or second fastener, and also minimizes the accumulation of water, dirt, or electrolysis solution in the space between the first and second connection surfaces. The second fastener is positioned lower than the first, thus minimizing physical contact between the second fastener and, for example, a body panel of the vehicle when the electrical measuring device is installed in the engine compartment.

[0007] In the preferred embodiment of the invention, the first connecting surface can rest on the same battery surface as the battery terminal. The second connecting surface, when in position, can be located lower than the battery terminal relative to the upper surface of the battery. In particular, it is advantageous that, when mounted, the second connecting surface be positioned lower than the upper surface of the battery. Therefore, if excessive rotation is required to connect the wiring harness to the second connecting element, a tool will strike the side of the battery, thus preventing the tool from contacting a different battery terminal than the one to which the first connecting element is connected, which would cause a short circuit between them.

[0008] The housing can be arranged so that it extends along a side surface of the battery that is closest to the battery terminal to which the first fastening element is attached.

[0009] This results in the housing striking the side wall of the battery if the current measuring device is unintentionally rotated around the first fastening element, thus preventing the first fastening element from detaching from the battery terminal.

[0010] The resistor has a U-shaped bend that is located inside the housing. Therefore, the first and second mounting elements are positioned close together, which allows for a reduction in the overall size of the current measuring device and effective use of the battery's side walls. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The present invention is more fully understood with reference to the following detailed description and the accompanying drawings of preferred embodiments of the invention, which, however, should not be regarded as limiting the invention to the specific embodiments, but merely as serving the purpose of explanation and understanding.

[0012] The drawings contain:

[0013] Fig. 1 a partially cutaway view of an electrical current measuring device according to the invention, which is arranged in conjunction with a storage battery;

[0014] Fig. 2 a side view of the in Fig. 1 current measuring device shown;

[0015] Fig. 3 a side view of the in Fig. 1 current measuring device shown and

[0016] Fig. 4. A circuit diagram showing the circuit structure of the [system / device]. Fig. 1 shows the current measuring device. DESCRIPTION OF PREFERRED EXECUTION FORMS

[0017] Referring to the drawings, which bear the same reference numerals to the same parts in the various views, in particular in the Fig. 1 to Fig. 3. Note that an electrical current measuring device will be used. 100 shown according to the present invention. Fig. 1 is a partially cutaway view of an electrical current measuring device according to the invention, which is used in conjunction with a storage battery 200 It is installed in the engine compartment of a motor vehicle. Fig. 2 is a side view of the current measuring device 100 . The Fig. Figure 3 is a perspective view of the current measuring device. 100 .

[0018] The current measuring device 100 closes a busbar 110 , a circuit board 120 , a case 130 , a plug socket 140 and a cover 150one. The busbar 110 It consists of a conductive material and serves as a parallel resistor. On the circuit board 120 A current measuring circuit is installed, which measures a differential potential between two points on the busbar. 110 monitored along the direction in which the current flows through it, in order to detect the current passing through the busbar 110 to measure or determine flowing electric current. The housing 130 The busbar is located therein 110 and the circuit board 120 up. In the plug socket 140 are a plurality of electrical components connected to the circuit board 120 connected plug connectors 142 arranged. The housing 130 It has a chamber in which the circuit board is located. 120 is attached. The cover 150 is inside the case 130 fitted to close the chamber.

[0019] The busbar 110It is U-shaped, with a reversal point located within the chamber. The busbar 110 It has end sections, one of which is the first fastening section. 112 to the battery 200 is attached or connected to establish an electrical connection with the battery 200 to produce and whose other than second fastening section 114 It serves as a housing to which an electrical wiring harness is attached or connected. 130 is essentially a rectangular parallelepiped and extends, as in Fig. 1. To be seen, over a given length in the vertical direction. The casing 130 is located above one of the side surfaces of the battery 200 attached to a terminal block 202 the battery 200 nearest to where the current measuring device is located 100 is connected. The first and second fastening sections 112 and 114 lie, as from the Fig. 2 and Fig. 3 can be seen on opposite sides of a main body of the housing. 130 and extend in opposite directions, horizontally or at right angles to the length of the case 130 .

[0020] The first fastening section 112 It has a C-shape in cross-section. In other words, the first fastening section has, as is clearly shown in Fig. Figure 3 shows a base and two upright side walls extending perpendicularly from the ends of the base. The base has a circular opening formed within it. 112A Back to Fig. 1. Referring to a metallic arm serving as a terminal block 210 at the negative (-) pole 202 the battery 200 fastens and connects the first fastening section 112 the busbar 110 electrically powered by the battery 200and thereby closes the current measuring device 100 to the battery 200 on. The metallic boom 210 functions as an electrical conductor, providing the electrical connection between the current measuring device 110 and the battery 200 manufactures. The metallic boom 210 It has at one end a vertical extension to the metallic boom. 210 extending bolts 211 Attaching the first fastening section 112 on the metallic boom 210 is achieved by inserting the bolt 211 of the metallic boom 210 through an open end of the first fastening section 112 into the hole 112A achieved by placing a (not shown) nut on the bolt 211 is tightened to secure the first fastening section 112 securely on the metallic boom 210to be held in place. The bottom (i.e., a strip) of the first fastening section. 112 serves, as in Fig. 2 shown, as the first connection surface 112B , with which the metallic boom 210 is securely connected.

[0021] The second fastening section 114 the busbar 110 It has a circular hole at one end through which a bolt can be inserted. 115 is plugged in. The wiring harness 300 is electrically connected to the second mounting section 114 connected. A connector. 302 is with the wiring harness 300 The components are connected, and a circular hole is formed in one end section. The connection between the connector piece... 302 and the second fastening section 114 is achieved by inserting the [item] on the second fastening section 114 provided bolt 115 into the hole of the connector 302and tightening a (not shown) nut on the bolt 115 for fixing the connector 302 on the second fastening section 114 . An upper surface of the second fastening section 114 serves, as in Fig. 2 shown, as the second connecting surface 114B , where the connecting piece 302 securely fastened.

[0022] The case 130 It consists of a resin, such as PPS (polyvinyl sulfide), which has greater electrical insulation and thermal conductivity. A larger part of the busbar 110 , except for the first and second fastening sections 112 and 114 , is with the resin in the housing 130 oversprayed.

[0023] The positioning and orientation of the first and second fastening sections 112 and 114 will now be described. In particular, the first connecting surface 112Bof the first fastening section 112 , on which the metallic boom 210 is attached, and the second connecting surface 114B of the second fastening section 114 , where the connecting piece 302 of the wiring harness 300 appropriate, as is clearly stated in Fig. 1 is shown, parallel to the upper surface of the battery 200 arranged.

[0024] The first and second connecting surfaces 112B and 114B are near the upper part of the battery 200 positioned when they are installed in their place within the engine compartment of the motor vehicle. The second connecting surface 114B is located within the engine compartment in a lower position than the first connecting surface 112B . With "the upper part of the battery 200 “As it is used here, the area around the upper surface 200A the battery 200meant. The second connecting surface 114B is positioned so that the upper end of the second fastening section 114 arranged bolt 115 is maintained at a higher level than the upper surface 200A the battery 200 .

[0025] The first connecting surface 112B is on the same upper surface (i.e., the upper surface) 200A ) the battery 200 positioned like the terminal block 202 The second connecting surface 114B is at a lower level than that of the terminal block 202 and the upper surface 200A the battery 200 positioned.

[0026] The Fig. Figure 4 shows a circuit structure in conjunction with the battery. 200 positioned current measuring device 100 The current measuring device 100 The circuit board has 120 , on which a differential amplifier10 , a differential amplifier 12 , a temperature sensor 20 , a current detection processor 30 , a voltage detection processor 32 , a temperature measurement processor 34 , a circuit that determines the state of charge of the battery (SOC (State of Charge) circuit) 36 , a charge control 40 , input / output circuits used for communication 50 and 52 , a CAN interface 60 and a LIN interface 62 are manufactured. The differential amplifier 10 is connected to the ends of a parallel resistor 100' connected, which is connected by a section of the busbar 110 is formed. The differential amplifier 12 is connected to the positive (+) and negative (–) terminals of the battery 200 connected. The CAN interface 60 It is used to transmit and receive data according to a CAN protocol. The LIN interface62 It is used to transmit and receive data according to a LIN protocol. The differential amplifier 10 serves to reduce the resistance across the parallel resistance 100' to amplify the developed voltage. The current detection processor 30 serves to, based on the differential amplifier 10 output voltage, across the parallel resistor 100' to detect flowing electric current and to define a characteristic output as a function of the current supplied by the battery. 200 to the cable harness 300 to supply flowing current. The differential amplifier 10 and the current detection processor 30 They serve as a current measuring circuit. The differential amplifier 12 converts the voltage as it exists between the positive and negative terminals of the battery. 200 The voltage is generated (i.e., a battery voltage) and converted into a selected voltage level. The voltage detection processor 32is based on the differential amplifier 12 The output voltage determines the battery voltage. The temperature sensor 20 It consists of a voltage divider made of resistors and a thermistor. The thermistor has a resistance value that changes with the ambient temperature in order to modify a portion of the voltage applied to the voltage divider. The temperature detection processor 34 monitors the part of the temperature sensor 20 output voltage to measure the temperature of the current measuring device 100 (i.e., the battery temperature) 200 ) to determine. The circuit that determines the battery's state of charge (SOC). 36 queries the outputs of the current detection processor 30 , of the voltage detection processor 32 and the temperature detection processor 34 to generate a signal about the battery's state of charge. The current sensing processor30 , the voltage detection processor 32 , the temperature detection processor 34 and the circuit that determines the battery's state of charge 36 serve as a state of charge (SOC) sensor 38 The charge control 40 This is queried by the circuit that determines the battery's state of charge (SOC). 36 output signal to control the electricity generation (i.e., output power) of an onboard electric generator 80 to control the vehicle. In particular, the load control. 40 indicates one in the generator 80 built-in generator control 82 about the input / output circuit used for communication 52 and the LIN interface 62 a control signal that regulates the power output by the generator 80 controls the circuit that determines the battery's state of charge. 36The signal indicating the battery's state of charge is transmitted via the input / output circuit used for communication. 50 and the CAN interface 60 to a vehicle control system 70 issued. The vehicle control system 70 It serves to execute predefined integrated control functions based on the battery's state of charge, for controlling the actions of the engine and various on-board electrical loads.

[0027] The current measuring device 100 As described above, it is designed to have a first and a second connecting surface. 112B and 114B exhibits which are near the upper area of ​​the battery 200 and parallel to the upper surface 200A the battery 200 are aligned, thus enabling the attachment of the first fastening section 112 on the boom 210 and the connection between the second fastening section 114and the wiring harness 300 near the upper surface 200A the battery 200 This simplifies the process. This results in improvements in the feasibility of mounting the current measuring device. 100 at the battery 200 The first and second connecting surfaces 112B and 114B differ in level with respect to the upper surface 200A the battery 200 , if they are mounted inside the engine compartment, so that there is no obstruction of the use of a tool used to connect the first or second fastening section 112 and 114 with the associated boom 210 or the associated connector 302 is used when working on the other of the first or second fastening sections. 112 and 114This avoids the accumulation of water, dirt, or electrolysis solution in the space between the first and second connection surfaces. 112B and 114B minimized.

[0028] The first connecting surface 112B of the first fastening section 112 is essentially positioned at the same level as the terminal block 202 the battery 200 , while the second connecting surface 114B of the second fastening section 114 is in a lower position than the terminal block 202 In other words, the first connecting surface 112b and the terminal block 202 are above the upper surface 200A arranged, while the second connecting surface 114B below the upper surface 200A is arranged. Therefore, if a tool is excessively rotated to fit the wiring harness, it will strike the wiring harness. 300with the second fastening section 114 to connect, on the side wall of the battery 200 on, thereby making contact between the tool and the positive terminal of the battery 200 This avoids a short circuit between them.

[0029] The case 130 has, as described above, a vertical axis to the battery 200 extending body and stores in it the section of the busbar 110 and the circuit board 120 The casing 130 is along the side surface of the battery 200 arranged, which are connected to the terminal block 202 nearest. This results in the case 130 on the side wall of the battery 200 triggers when the current measuring device 100 unintentionally around the first fastening section 11112 is rotated, which loosens the first fastening section of the boom. 210 is avoided.

[0030] The busbar 110 The U-shaped turn inside the housing 130 open, so that the first fastening section 112 and the second fastening section 114 are closely adjacent to each other, thus reducing the overall size of the current measuring device 100 is permitted and the side walls of the battery 200 can be used effectively.

[0031] While the present invention has been described in terms of a preferred embodiment to facilitate its better understanding, it should be borne in mind that the invention can be embodied in various ways without deviating from its principle. Therefore, the invention should be understood to include all possible variations of the embodiment shown that can be embodied without deviating from the principle of the invention as set forth in the appended claims.

[0032] For example, the current measuring device 100 at the negative (-) pole 202 the battery 200 connected, but can alternatively be connected to the positive terminal of the battery 200 be connected.

[0033] The case 130 is arranged so that it runs along the side wall of the battery 200 lies, which is the terminal block 202 it is closest, but alternatively it can also be opposite another side wall of the battery 200 can be arranged if the distance between the terminal block 202 and the current measuring device 100 depending on the length of the metallic boom 210 and the first fastening section 112 is undesirably long.

[0034] The chamber in the housing 130 , in which the circuit board 120 is housed by a cover 150It is sealed, but alternatively it can be filled with, for example, epoxy resin to encapsulate the circuit board.

[0035] The parallel resistor 100' is from a section of the busbar 110 formed, but can alternatively also be from the busbar 110 be separated and arranged in an area where the potential difference between two points is measured in order to measure the current flowing across the busbar 110 flows. QUOTES INCLUDED IN THE DESCRIPTION

[0036] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0037] JP 2005-188945

[0002]

Claims

[1] Device for measuring electric current, measuring a current flowing between a battery and a wiring harness, comprising: a first fastening element which is to be electrically fastened to a battery terminal; a second fastening element with which the wiring harness can be electrically fastened; a resistor arranged between the first and second fastening element: a circuit board on which a current measuring circuit is arranged, which is suitable for measuring the current flowing through the resistor as a function of the current flowing between the battery and the wiring harness on the basis of the potential difference between two points defined on the current path passing through the resistor, and a housing arranged between the first and second mounting elements, in which the resistor and the circuit board are arranged, wherein the first fastening element has a first connecting surface for electrical connection with the battery terminal and the second fastening element has a second connecting surface for electrical connection with the wiring harness, and the first and second connecting surfaces, when mounted in their position, are oriented such that they are substantially parallel to the upper surface of the battery, and, where, with respect to the upper surface of the battery, the second connecting surface is in a lower position than the first connecting surface when they are mounted in their position. [2] Device for measuring electric current according to claim 1, wherein, when mounted in their position, the first connecting surface is in the same surface of the battery as the terminal of the battery, and the second connecting surface is in a lower position than the terminal of the battery with respect to the upper surface of the battery. [3] Device for measuring electric current according to claim 2, wherein, when mounted in their position, the second connecting surface is in a lower position than the upper surface of the battery. [4] Device for measuring electric current according to claim 1, wherein the housing is arranged such that it extends along a side surface of the battery which is closest to the terminal of the battery to which the first fastening element is attached. [5] Device for measuring electric current according to any one of claims 1 to 4, wherein the resistor has a U-shaped bend which is arranged inside the housing.

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