Resistive element and method for manufacturing a resistive element

Abstract

The invention relates to a resistor element (10) for a battery sensor, comprising a first connecting element (12) and a second connecting element (14) as well as a first measuring resistor (16) and a second measuring resistor (18), wherein the first measuring resistor and the second measuring resistor are arranged electrically in series between the first connecting element (12) and the second connecting element (14), wherein a conductive intermediate element is provided between the first measuring resistor and the second measuring resistor (18), wherein the first measuring resistor is connected to the first connecting element with a first edge and the second measuring resistor is connected to the second connecting element with a first edge, and wherein the first measuring resistor (16) and the second measuring resistor (18) are each connected to the intermediate element (20) with a second edge. The first edge of the first measuring resistor (16) and the first edge of the second measuring resistor (18) and / or the second edge of the first measuring resistor (16) and the second edge of the second measuring resistor (18) are each located substantially on a common straight line.

Description

Technical Field

[0001] The present invention relates to a resistor element for a battery sensor, comprising a first connecting element and a second connecting element and a first measuring resistor and a second measuring resistor, wherein the first measuring resistor and the second measuring resistor are arranged electrically in series between the first connecting element and the second connecting element. The present invention also relates to a method for manufacturing such a resistor element. Background Art

[0002] Battery sensors are used in vehicles to obtain information about the battery status, such as the battery's state of charge. Battery parameters to be detected include, for example, battery voltage, battery current, and battery temperature. Battery voltage and battery current must be continuously detected, in particular, to accurately determine the battery status, such as the state of charge.

[0003] Current detection is performed, for example, by detecting a voltage drop across a measuring resistor arranged in the load current path. The measuring resistor is part of a resistance element that has corresponding connection elements for connecting the measuring resistor to a cable connection and a battery terminal. The resistance value of the measuring resistor is known very precisely. From the detected voltage drop, the current flowing through the measuring resistor, i.e., the load current, can be determined very precisely using Ohm's law.

[0004] The measuring resistor is usually made of a special alloy with a low temperature coefficient of resistance (ie, low sensitivity to temperature changes), such as copper-nickel-manganese alloy, so that the resistance can be determined very accurately and / or with very small changes.

[0005] The connecting section is usually made of a low-resistance copper alloy and is welded to the measuring resistor.

[0006] The copper alloy used for the conductor section has a high resistance-temperature dependence, ie a high resistance-temperature coefficient.

[0007] The measuring contacts are usually arranged on the line sections, so that the total resistance is formed by the resistance of the measuring resistor and the resistance of the line section between the measuring contacts.

[0008] Due to the high resistance-temperature dependence of the line sections, the line sections influence the overall resistance and thus the accuracy of the measurement.

[0009] The resistance characteristics of the measuring resistor and the conductor section at different temperatures are known, so that the exact resistance can be determined at a known temperature. However, an additional temperature sensor is required to determine the temperature.

[0010] However, a low temperature dependence of the total resistance is generally desirable in order to be able to achieve the most precise possible measurement.

[0011] Furthermore, resistor elements with multiple measuring resistors are known from the prior art. Battery sensors are designed to detect the voltage drop across the measuring resistors individually or collectively. Different measured values ​​allow, for example, more precise current measurement and / or calibration of the resistance of the individual measuring resistors.

[0012] However, the structure and manufacture of such a resistance element with multiple measuring resistors are very complex. In addition, such a resistance element usually requires a very large installation space. Summary of the Invention

[0013] The object of the present invention is to provide a resistance element having at least two measuring resistors arranged in series, which is easy to manufacture and requires as little installation space as possible. Furthermore, the resistance element should have a high measurement accuracy, in particular a low resistance-temperature dependence.

[0014] To achieve this object, a resistor element for a battery sensor is provided, the resistor element comprising a first and a second connecting element and a first and a second measuring resistor, wherein the first and the second measuring resistors are arranged electrically in series between the first and the second connecting elements, and wherein a conductive intermediate element is provided between the first and the second measuring resistors. The first and the second measuring resistors are each connected to the first or the second connecting element by a first edge and to the intermediate element by a second edge. The first edge of the first measuring resistor and the first edge of the second measuring resistor and / or the second edge of the first measuring resistor and the second edge of the first measuring resistor are each located substantially on a common straight line.

[0015] Therefore, the measuring resistors are not arranged on a common straight line, but are arranged adjacent to each other to a certain extent. Thus, the resistance element is designed to be U-shaped or wavy at least in the area of ​​the measuring resistor. Thus, a current flow path that is not linear passes through the resistance element. In particular, the main current direction passing through the directly adjacent area of ​​the measuring resistor and the connecting element or the intermediate element does not extend on the central axis of the corresponding component. This causes the current flow path in the adjacent area of ​​the measuring resistor and the conductor section to change or the potential line / equipotential line to change. By positioning the measuring contacts, the resistance-temperature correlation between these measuring contacts can be advantageously influenced, in particular reduced, in combination with the current flow path that changes due to the geometry of the resistance element or the potential line that changes, because the temperature-related influence of the conductor section becomes lower.

[0016] Preferably, the first and second edges of the first measuring resistor and / or the first and second edges of the second measuring resistor extend parallel to one another, so that the first and second edges of the measuring resistors each extend on a common straight line. In this embodiment, the measuring resistor is designed as a parallelogram or trapezoid. Such a resistor element is particularly easy to manufacture. The resistor element is typically made from a flat substrate. The flat substrate consists of a first section, a second section, and an elongated resistor section, wherein the first and second sections are made of conductive material, and the elongated resistor section is electrically conductively connected to one of the sections by two opposing edges. The substrate is supplied, for example, as a continuous material on a roll. The edges of the resistor sections extend parallel to one another, making it easy to cut parallelogram- or trapezoid-shaped measuring resistors from the substrate. The connecting elements are cut from one of the two sections, and the intermediate element is cut from the other section. Since the substrate only has one resistor section to produce a resistor element having two measuring resistors, simpler and more cost-effective manufacturing is also possible.

[0017] The free edge of the first measuring resistor connecting the first edge and the second edge of the first measuring resistor and / or the free edge of the second measuring resistor connecting the first edge and the second edge of the second measuring resistor can, for example, extend parallel to one another, so that the measuring resistors are designed as a parallelogram or a rectangle.

[0018] The first edge and / or the second edge can be designed to have different lengths, so that the measuring resistors are designed to have different widths, whereby they have different resistances. Using two different resistors can have advantages during measurement, since different voltage drops can be measured.

[0019] Alternatively, the first edge and / or the second edge can also be designed to have the same length, so that the resistance of the two measuring resistors is the same.

[0020] The longitudinal direction of the first coupling element and / or the longitudinal direction of the second coupling element preferably encloses an angle of less than 90°, in particular an angle of 0°, with the first edge of the respectively connected measuring resistor.

[0021] For example, the connecting elements can be arranged in the extension of the correspondingly connected measuring resistor. However, the connecting elements are preferably arranged such that the direction of the main current in the immediate vicinity of the measuring resistor and the connecting element changes through them. The longitudinal direction of the connecting elements preferably extends at a right angle, resulting in a strong change in the current direction.

[0022] Preferably, first measuring contacts are provided on the first and second coupling elements, wherein the measuring contacts are each provided on a section of the coupling element facing the respective other coupling element. In principle, the measuring contacts are arranged such that they are outside the main current flow direction. In particular, the measuring contacts can be arranged transversely to the longitudinal direction of the measuring resistor in such a way as to reduce and / or compensate for the effects of temperature-related resistance changes in the measuring resistor and / or the conductor sections.

[0023] Preferably, the intermediate element extends essentially in the direction of the second edge, so that a change in the main current direction also occurs between the measuring resistors.

[0024] In order to be able to detect the voltage drop across the individual measuring resistors, a second measuring contact associated with each measuring resistor is provided on the intermediate element. The second measuring contact is provided in a section of the conductor element facing away from the other measuring resistor, so that it is also located outside the main current path.

[0025] A third measuring contact can be provided on the intermediate element, which is arranged geometrically between the first measuring resistor and the second measuring resistor. This third measuring contact is located in the main current flow path and can be provided as an alternative or in addition to the second measuring contact.

[0026] In principle, the two measuring resistors are arranged and connected to one of the connecting elements or the intermediate element in such a way that a main current flow direction occurs in the immediate vicinity of the measuring resistors and the connecting and intermediate elements, which deviates from the geometric longitudinal direction of the measuring resistors, the connecting and intermediate elements. The measuring contacts are arranged such that they are not oriented in the main current flow direction, but are offset laterally.

[0027] To achieve this object, a method for manufacturing the above-mentioned resistor element for a battery sensor is also provided. The method comprises the following steps:

[0028] providing a planar substrate consisting of a first section, a second section and an elongated resistor section, wherein the first section and the second section are made of an electrically conductive material, wherein the elongated resistor section has two opposite edges, wherein the first section and the second section are each electrically conductively connected to one of the edges of the resistor section,

[0029] The resistor element is cut out from a substrate, wherein the first and second connecting elements are cut out from the first section, wherein the first and second measuring resistors are cut out from the resistor section, and wherein the intermediate element is cut out from the second section.

[0030] “Cutting out” in this context refers to any separation method by which the connecting elements, the measuring resistor and the intermediate elements can be separated from the substrate, for example laser cutting or punching. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Further advantages and features will be apparent from the following description in conjunction with the accompanying drawings. In the drawings:

[0032] Figure 1 A first embodiment of a resistance element according to the present invention is shown;

[0033] Figure 2 Show Figure 1 Schematic diagram of the current flow path in the resistance element;

[0034] Figure 3 A second embodiment of a resistance element according to the present invention is shown;

[0035] Figure 4 A third embodiment of a resistance element according to the present invention is shown; and

[0036] Figure 5 Shown for manufacturing Figure 1 The manufacturing steps of the resistor element. Specific implementation methods

[0037] exist Figure 1 1 shows a resistor element 10 for a battery sensor. Resistor element 10 has a first connection element 12 and a second connection element 14 for connecting resistor element 10 to a battery terminal and a cable. Resistor element 10 also has a first measuring resistor 16 and a second measuring resistor 18, which are arranged in series between first connection element 12 and second connection element 14. An intermediate element 20 is provided between first measuring resistor 16 and second measuring resistor 18.

[0038] A first measuring contact 22a, 22b is provided on each of the coupling elements 12, 14. Two second measuring contacts 24a, 24b are provided on the intermediate element 20, each of which is associated with one of the two measuring resistors 16, 18. Furthermore, a third measuring contact 26 is provided, which is arranged between the two second measuring contacts 24a, 24b.

[0039] The voltage drop across measuring resistor 16 or 18 can be measured via measuring contacts 22a, 24a or 22b, 24b, respectively. From this voltage drop, the current flowing through measuring resistor 16 or 18 can be determined using Ohm's law using the known or determined resistance of measuring resistor 16 or 18.

[0040] The connecting elements 12 , 14 and the intermediate element 20 are made of an electrically conductive material, for example copper or a copper alloy. The measuring resistors 16 , 18 are made of a material with a low resistance-temperature dependence, for example copper-nickel-manganese alloy.

[0041] The first measuring resistor 16 is connected to the first coupling element 12 by a first edge 28a and to the intermediate element 20 by a second edge 30a. The second measuring resistor 18 is connected to the second coupling element 14 by a first edge 28b and to the intermediate element 20 by a second edge 30b.

[0042] like Figure 1 It can be seen that the first edge 28a of the first measuring resistor 16 and the first edge 28b of the second measuring resistor 16 are arranged on a common straight line 32. Furthermore, the second edges 30a, 30b of the measuring resistors 16, 18 are likewise arranged on a common straight line 34.

[0043] The two measuring resistors 16 , 18 are therefore electrically connected in series, but geometrically they are adjacent to one another and form a U-shaped conductor section together with the intermediate element.

[0044] The connecting elements 12 , 14 or the intermediate element 20 have a different resistance than the measuring resistors 16 , 18 . In particular, the resistance-temperature dependence of the connecting elements 12 , 14 or the intermediate element 20 is greater than the resistance-temperature dependence of the measuring resistors 16 , 18 .

[0045] If current flows through the resistor element 10, it generally seeks the path of lowest resistance. The longitudinal direction of the coupling elements 12, 14 extends substantially at right angles to the longitudinal direction of the measuring resistors 16, 18, and the longitudinal direction of the intermediate element 20 also extends substantially at right angles to the longitudinal direction of the measuring resistors 16, 18. As a result, the direction corresponding to the current flowing from the first coupling element 12 to the second coupling element 14 changes, with the main current direction 36 at least partially not corresponding to the longitudinal direction of the measuring resistors 16, 18 or the longitudinal direction of the coupling elements 12, 14 and the intermediate element 20.

[0046] In particular, the main current direction 36 extends in the region of the inner corners 38 a , 38 b , 40 a , 40 b between the connecting elements 12 , 14 and the measuring resistors 16 , 18 or between the measuring resistors 16 , 18 and the intermediate element 20 .

[0047] like Figure 2 As can be seen, the first measuring contacts 22a, 22b are arranged on regions of the connecting elements 12, 14 facing away from the inner corners 38a, 38b. Furthermore, the second measuring contacts 24a, 24b are also arranged on regions of the intermediate element 20 facing away from the inner corners 40a, 40b. Consequently, the measuring contacts 22a, 22b, 24a, 24b are arranged outside the main current direction 36. Consequently, the direct connection between the first measuring points 22a, 22b and the respectively associated second measuring points 24a, 24b does not correspond to the main current direction 36, but rather extends at an angle thereto.

[0048] Temperature changes can cause changes in the resistance of the connecting elements 12, 14 and the intermediate element 20, as well as the measuring resistors 16, 18. Since the connecting elements 12, 14 and the intermediate element 20 have a greater resistance-temperature dependence, temperature changes have a greater effect on the resistance of these elements 12, 14, 20. Consequently, temperature changes can cause changes in the resistance within the resistor element 10, which can cause a change in the main current direction 36.

[0049] The measuring contacts 22a, 24a and 22b, 24b are each arranged in such a way that a temperature-dependent change in the resistance of the connecting elements 12, 14 or the intermediate element 20 and an adaptation of the main current path 36 based on the temperature-dependent change in resistance are at least partially, in particular completely, balanced, so that a temperature-dependent change in the resistance of the connecting elements 12, 14 or the intermediate element 20 can be compensated.

[0050] Instead of the second measuring contacts 24a, 24b, a third measuring contact 26 can be used, so that only one measuring contact 26 is required on the intermediate element 20. However, the third measuring contact can also be used as an additional contact in the main current path 36, wherein, for example, the voltage drop measured between the first measuring contact 22a and the second measuring contact 24a can be compared with the voltage drop measured between the first measuring contact 22a and the third measuring contact 26.

[0051] Figure 1 The resistor element 10 shown can be formed in a simple manner by Figure 5 The substrate 40 shown is made.

[0052] Substrate 40 is comprised of a first section 42, a second section 44, and an elongated resistor section 46. First section 42 and second section 44 are made of a conductive material, such as copper or a copper alloy. Elongated resistor section 46 is made of a resistive material, such as a copper-nickel-manganese alloy. Resistor section 46 has two opposing edges 48, 50, with first section 42 and second section 44 each being electrically conductively connected to one of edges 48, 50 of resistor section 46.

[0053] The resistor element 10 is cut out of the substrate 40 , wherein the first connecting element 12 and the second connecting element 14 are cut out of the first section 42 , the first measuring resistor 16 and the second measuring resistor 18 are cut out of the resistor section 46 , and the intermediate element 20 is cut out of the second section 44 .

[0054] Although the substrate 40 has only one resistor section 46 , two measuring resistors 16 , 18 arranged in series can be produced from the substrate 40 due to the shape of the resistor element 10 .

[0055] The advantage of this production method is also that the shape of the measuring resistors 16, 18, the shape of the connecting elements 12, 14 and the shape of the intermediate element 20 can be selected arbitrarily. In particular, different shapes can be provided for the measuring resistors 16, 18.

[0056] For example, the measuring resistors 16, 18 can be provided with different widths so that they have different resistances (see Figure 3 ).

[0057] In the embodiments shown so far, measuring resistors 16, 18 have a rectangular shape. However, it is also possible for the free edges of measuring resistors 16, 18 not to extend parallel to one another and / or not to extend perpendicularly to edges 22a, 22b, 24a, 24b. In particular, measuring resistors 16, 18 can also be designed as a parallelogram or trapezoid.

[0058] In addition, the coupling elements 12, 14 can also be designed arbitrarily. In particular, the longitudinal direction of the coupling elements 12, 14 can be designed arbitrarily. Figure 4 In the embodiment shown, the coupling elements 12 , 14 are arranged with their longitudinal axes extending in the direction of the longitudinal axes of the measuring resistors 16 , 18 .

[0059] Independently of the shape of the measuring resistors 16 , 18 and independently of the orientation of the coupling elements 12 , 14 , the measuring contacts 22 a , 22 b , 24 a , 24 b are arranged such that they can compensate for or completely balance temperature-related resistance fluctuations of the coupling elements 12 , 14 , the measuring resistors 16 , 18 and the intermediate element 20 .

Claims

1. A resistance element (10) for a battery sensor, comprising a first connecting element (12) and a second connecting element (14) and a first measuring resistor (16) and a second measuring resistor (18), wherein: A first measuring resistor (16) and a second measuring resistor (18) are arranged electrically in series between a first connecting element (12) and a second connecting element (14), wherein a conductive intermediate element (20) is provided between the first measuring resistor (16) and the second measuring resistor (18), wherein the first measuring resistor (16) is connected to the first connecting element (12) by means of a first edge (28a), and the second measuring resistor (18) is connected to the second connecting element (14) by means of a first edge (28b), wherein the first measuring resistor (16) and the second measuring resistor (18) are connected to the intermediate element (20) by means of second edges (30a, 30b), respectively, characterized in that A first edge (28a) of the first measuring resistor (16) and a first edge (28b) of the second measuring resistor (18) and / or a second edge (30a) of the first measuring resistor (16) and a second edge (30b) of the second measuring resistor (18) are respectively located on a common straight line (32, 34); first measuring contacts (22a, 22b) are provided on the first connecting element (12) and the second connecting element (14); the first measuring contacts (22a, 22b) are respectively provided on a section of the connecting element (12, 14) facing the respective other connecting element (12, 14); and second measuring contacts (24a, 24b) respectively associated with one measuring resistor (16, 18) are provided on the intermediate element (20); the second measuring contacts (30a, 30b) are respectively arranged in a section of the intermediate element (20) facing away from the other measuring resistor (16, 18).

2. The resistor element according to claim 1, wherein: The first edge (28a) and the second edge (30a) of the first measuring resistor (16) and / or the first edge (28b) and the second edge (30b) of the second measuring resistor (18) extend parallel to one another.

3. The resistor element according to claim 1, wherein: The free edge of the first measuring resistor (16) connecting the first edge (28a) and the second edge (30a) of the first measuring resistor (16) and / or the free edge of the second measuring resistor (18) connecting the first edge (28b) and the second edge (30a) of the second measuring resistor (18) extend parallel to each other.

4. The resistor element according to claim 1 or 2, characterized in that: The first edges (28a, 28b) and / or the second edges (30a, 30b) are designed to have different lengths.

5. The resistor element according to claim 1 or 2, characterized in that: The first edges (28a, 28b) and / or the second edges (30a, 30b) are designed to have the same length.

6. The resistor element according to claim 1 or 2, characterized in that: The longitudinal direction of the first coupling element (12) and / or the longitudinal direction of the second coupling element (14) encloses an angle of less than 90° with a first edge (28a, 28b) of the correspondingly connected measuring resistor (16, 18).

7. The resistor element according to claim 1 or 2, characterized in that: The intermediate element (20) extends substantially in the direction of the second edge (30a, 30b).

8. The resistor element according to claim 1 or 2, characterized in that: A third measuring contact (26) is provided on the intermediate element (20), which is arranged geometrically between the first measuring resistor (16) and the second measuring resistor (18).

9. The resistor element according to claim 6, wherein: The angle is an angle of 0°.

10. A method for producing a resistance element (10) according to any one of the preceding claims, the resistance element being used for a battery sensor, the method comprising the following steps: - providing a flat substrate (40) consisting of a first section (42), a second section (44) and an elongated resistive section (46), wherein The first section (42) and the second section (44) are made of an electrically conductive material, wherein the elongated resistor section (46) has two opposite edges (48, 50), wherein the first section (42) and the second section (44) are each electrically conductively connected to one of the edges (48, 50) of the resistor section (46). - Cutting out the resistor element (10) from a substrate (40), wherein the first connecting element (12) and the second connecting element (14) are cut out from the first section (42), wherein the first measuring resistor (16) and the second measuring resistor (18) are cut out from the resistor section (46), and wherein the intermediate element (20) is cut out from the second section (44).

11. The method according to claim 10, characterized in that The battery sensor is a battery sensor used in a vehicle.

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