WO2020078814A1

WO2020078814A1 - Resistance assembly, method for producing a resistance assembly, and battery sensor

Info

Publication number: WO2020078814A1
Application number: PCT/EP2019/077440
Authority: WO
Inventors: Henryk Frenzel
Original assignee: Continental Automotive Gmbh
Priority date: 2018-10-15
Filing date: 2019-10-10
Publication date: 2020-04-23
Also published as: DE102019215502A1

Abstract

The invention relates to a resistance assembly (22) for a battery sensor (10), in particular for a vehicle battery, comprising two conduction portions (12, 16) and a resistance element arranged between the conduction portions. The conduction portions (12, 16) are electrically conductively connected, by means of respective joining surfaces (26a, 26b), to respective contact surfaces (24a, 24b) of the resistance element (20). At least one conduction portion (12, 16) has increased strength, in particular increased flexural rigidity, at least in a region (30) adjoining the joining surface (26a, 26b). The invention further relates to a battery sensor (10) having a resistance assembly (22) of this type and to a method for producing a resistance assembly (22) of this type.

Description

description

Resistor assembly and method for manufacturing a

Resistor assembly and battery sensor

The invention relates to a resistance module for a battery sensor, in particular for a vehicle battery, with two line sections and a resistance element arranged between the line sections, the line sections each being electrically conductively connected to a contact surface of the resistance element with a wing surface. The invention further relates to a method for producing such a resistor assembly. Furthermore, the invention relates to a battery sensor with such a resistance assembly

Battery sensors are used in vehicles to record battery parameters of the vehicle battery in order to be able to make statements about the state of charge and / or the state of health of the battery. The battery parameters to be recorded are, for example, the battery voltage, the battery current and the temperature of the battery. In particular, the battery voltage and the battery current ideally have to be permanently recorded in order, for example, to be able to make an exact statement about the state of charge of the battery.

The battery sensor is usually arranged on one of the battery poles and has, for example, a battery pole terminal for contacting the vehicle battery. Furthermore, the battery sensor has a cable connection for a cable, for example a ground cable.

For example, a resistance element arranged in the current path of the load current is provided to detect the battery current. The resistance element is electrically conductively connected to two line sections, which are formed by the battery terminal and the cable connection, so that the entire load current flows through the resistance element. The line sections and the resistance element together form one Resistor assembly. Furthermore, a voltage detection device is provided for detecting a voltage drop dropping across the resistance element. If the electrical resistance of the resistance element is known, the current flowing across the resistance element, that is to say the battery sensor, can be calculated from Ohm's law from the detected voltage drop across the resistance element.

Due to the installation situation in a vehicle, in particular in a Polish of a vehicle battery, the battery sensor has to be very compact. In addition, high demands are placed on the battery sensor in terms of mechanical stability. In normal vehicle operation, there are strong mechanical loads, such as shocks or vibrations. Large forces, which are also transmitted to the battery sensor, can act in particular on the ground cable. The battery sensor must ensure a secure electrical connection of the cable of the vehicle battery connected to the cable connection in the event of all loads occurring in the vehicle. Up to now, additional stiffening elements have often been used to increase the stability of the battery sensor. However, additional work steps are required during assembly.

The object of the invention is to provide a resistance module for a battery sensor and a battery sensor which are simple to manufacture and have sufficient mechanical stability for the loads occurring in vehicle operation. The object of the invention is further to provide a method for producing such a resistor assembly.

To solve the problem, a resistor assembly for a battery sensor, in particular for a vehicle battery, has two line sections and a resistance element arranged between the line sections, the line sections each being electrically conductively connected to a contact surface of the resistance element with a wing surface, at least a line section at least on one to the Joining area adjacent area has increased strength, in particular increased bending rigidity.

Different requirements are placed on the material of the line sections. The area of the line sections from which the battery pole terminal or a cable connection is formed must be flexible, for example in order to produce the battery pole terminal from the line section by means of a bending process. In addition, a certain flexibility of the battery pole clamp is required in order to be able to clamp it to the battery pole. In areas that adjoin the resistance element, on the other hand, the line sections should have a high strength, in particular a high bending stiffness, in order to be able to absorb the loads acting on the battery sensor. In the present case, this is achieved by increasing the strength in this area. This means that additional stiffening elements can be dispensed with.

The higher strength can be produced in different ways. For example, the thickness of the line section can be increased at least in the area adjacent to the joining surface. In the prior art, the line sections are made of a material with a constant thickness. This has manufacturing reasons. For example, the line sections and the resistance element are connected to one another in a continuous joining process, for example an electron beam process, the same welding parameters always being used. Different materials, on the other hand, require different welding parameters that were not possible with the previously used processes. In order to connect the line sections and the resistance element to one another, a single welding method is used to solve the task, in which the welding parameters (energy, pressure, time, etc.) can be individually adapted to the respective welded connection.

The thickness of the material can therefore be matched to the desired material property of the line section in this area. In an area that forms the battery pole clamp, the material can be thinner, so that this is more flexible and can be processed more easily, in particular deformed. In the area adjacent to the joint surface, on the other hand, the material is thicker, so that it can absorb higher loads without being deformed or damaged.

Another possibility of increasing the strength is that the line section in the area adjacent to the joining surface consists of a material with increased strength, in particular with increased bending stiffness. That is, the material thickness can remain the same while increasing the strength of the material so that the desired strength of the material is achieved.

For example, the line section in a region adjacent to the joining surface can have a material with a different chemical composition than the rest of the line section, in particular a different alloy. The material composition, in particular the alloy, is selected so that it has the desired properties. For example, different copper alloys can be used, so that a very good electrical conductivity of the entire line section is always ensured. For example, a CuFeO.I P alloy can be used for the area of the line section with increased strength and a CUFE2P alloy for the remaining line section.

However, the line section can consist of the same material throughout and the strength of the material of the line section in the area adjacent to the joining surface has been increased by a post-treatment, in particular by a heat treatment or a roller treatment. This enables a simpler production of the line section, since it consists of the same material throughout and can be shaped, for example punched out or cut out, from the same. The area of the line section in which a higher strength is desired is then subjected to an aftertreatment which increases the strength. In order to additionally increase the stability of the resistance group, it can be provided, for example, that at least one contact surface extends at an angle of 30 ° to 60 °, in particular at an angle of 45 °, to the longitudinal axis of the resistance element. Are the line sections and the resistance element angled at an angle of 90 ° to one another in order to achieve the most compact possible construction of the resistance assembly and the battery sensor. However, this often results in a high load peak in the area of the 90 ° corner, with a tensile force acting on the earth cable, which necessitates strengthening the resistance module in this area. These forces can be absorbed in this area on the one hand by increasing the strength of the line section described above. In which the contact surface is not at right angles, but is inclined, there is no sharp 90 ° corner between the resistance element and the line section, but a corner with a smaller angle, which reduces the load peak in the area of the corner.

In order to achieve this effect, at least one joining surface can also run at an angle of 30 ° to 60 °, in particular at an angle of 45 °, to the longitudinal axis of the line section.

The joining surfaces and the contact surfaces are preferably designed such that the longitudinal axis of at least one line section and the longitudinal axis of the resistance element are angled relative to one another, in particular enclose an angle of at least 45 °, in particular 90 °. A very compact resistor assembly can thus be provided.

In particular, the line sections are angled relative to one another, in particular at an angle of 90 °.

To achieve the object, a battery sensor is also provided with a resistance module as described above and with a detection device for detecting a voltage drop across the resistance element. To achieve the object, a method for producing a battery sensor according to one of the preceding claims is also provided, with the following steps:

Provision of the line sections and the resistance element, at least one line section having increased strength in an area adjacent to a joining surface,

- Aligning the line sections and the resistance element in such a way that the line sections each make contact with a joining surface on a contact surface of the resistance element,

- Cohesive connection of the line sections and the resistance element at the contact areas, the cohesive connection being carried out by a single welding process.

The individual welding process allows the welding parameters to be individually adapted to the material properties of the area of the line section adjoining the wing surface.

The strength of an area adjacent to the joining surface can be increased on at least one line section by a post-treatment.

Further advantages and features emerge from the following description in conjunction with the accompanying drawings. In this show:

1 shows a battery sensor from the prior art;

Figure 2 shows the resistor assembly according to the invention for one

Battery sensor;

Figure 3a shows a detailed view of a second embodiment of a

Resistor assembly;

Figure 3b shows a detailed view of a third embodiment of a

Resistor assembly; and Figure 4 shows a fourth embodiment of a resistor assembly.

FIG. 1 shows a battery sensor 10 for recording battery parameters. The battery sensor 10 has a first line section 12, which has a battery pole terminal 14, and a second line section 16, which has a cable connection 18 for a cable, for example a ground cable. The line sections 12, 16 are electrically connected to one another via a resistance element 20. The line sections 12, 16 and that

Resistor element 20 together form a resistor assembly 22 shown in detail in FIG. 2.

The resistance element 20 is in each case electrically conductively connected to a joining surface 26a, 26b of the line sections 12, 16 with a contact surface 24a, 24b.

Furthermore, the battery sensor has a housing 28 which encloses the resistance element 20 and at least in sections the line sections 12, 16.

An evaluation unit (not shown in detail here) for evaluating the battery values detected with the battery sensor 10 is provided in the housing 28. The evaluation unit comprises, for example, a voltage detection device for detecting a voltage drop across the resistance element 20. The voltage detection device is contacted with contact points 33a, 33b in front of and behind the resistance element 20. A plug connection 31 for outputting a measurement signal, for example to a vehicle control, is provided on the housing.

The electrical resistance of the resistance element 20 is known. The current flowing via the resistance element 20, that is to say the battery sensor 10, can be determined from the known electrical resistance of the resistance element 20 and the detected voltage drop. The resistance element 20 can consist of a material with low temperature dependence, for example one

Copper-nickel-manganese alloy. Alternatively or additionally, the evaluation unit can determine a correction value for the electrical resistance in order to correct a change in the electrical resistance, for example due to aging phenomena or temperature changes.

As can be seen in particular in FIG. 2, the longitudinal axis 32 of the first line section 12 runs parallel to the longitudinal axis 34 of the resistance element 20. The longitudinal axis 36 of the second line section 16 runs perpendicular to the longitudinal axis 34 of the resistance element 20. This makes the battery sensor 10 very compact, so that this can be used, for example, in the Polish of a vehicle battery.

The right-angled arrangement of the resistance element 20 and the second line section 16 results in an inside corner 38 on the battery sensor. If tensile forces 40 act on the cable that is connected to the second line section 16, this inside corner is heavily loaded, in particular by notch stresses.

Resistor assemblies 22 or battery sensors 10 are therefore known from the prior art, which have an additional reinforcing element that connects the resistance element 20 to at least one of the line sections 12, 16 and supports them. At least part of the force acting on the second line section 16 is thus dissipated via the reinforcing element. However, the reinforcing element must be connected to the line section 12, 16 and / or the resistance element 20, which requires additional work steps.

In the resistor assembly 22 shown in FIG. 2, the second line section 16 has an increased strength, in particular an increased bending stiffness, in an area 30 adjoining the joining surface 26b. In the embodiment shown in FIG. 2, the increased strength of the area 30 is achieved in that the area 30 is made of a material that has an increased strength compared to the rest of the line section 16. In the embodiment shown here, the area 30 consists of the same material as the rest of the line section 16. The increased strength was achieved by post-treatment of the material. This can be, for example, a heat treatment or a roll treatment. The line section 16 is therefore also made in one piece from one material, only the area 30 of the line section 16 being post-treated in such a way that it has increased strength compared to the rest of the line section 16.

The region 30 can also consist, for example, of a material with a different chemical composition than the rest of the line section, in particular of a different alloy. The chemical composition or the alloy can be chosen arbitrarily in order to achieve the desired strength, in particular the desired bending stiffness. The chemical composition is only to be selected in such a way that a good mechanical and electrical connection with the resistance element 20 is possible. The area 30 is connected in advance to the rest of the line section 16 and then connected to the resistance element 20. For example, different copper alloys, for example CuFeO.I P and CuFe2P, are used for the line section 16 and the region 30. In addition, materials with different R values can be used, for example with an R value of R300 and R420.

A further possibility for increasing the strength of the area 30 is shown in FIGS. 3a and 3b. The line section 16 is made of one material throughout. In order to increase the strength of the area 30, the thickness of the material in the area 30 is increased in comparison with the other line section 16. As a result, the bending stiffness is significantly higher. In FIG. 3a, the thickness increases starting from the joining surface 26b, so that the joining surface has the same dimensions as the corresponding contact surface 24b.

In FIG. 3b, the area 30 has a constant thickness that is greater than that of the rest of the line section 16 and the resistance element 20.

Until now, it was necessary for manufacturing reasons that the line section 16 and the resistance element 20 have a constant thickness. For example, the line sections and the resistance element were connected to one another in a continuous joining process, for example an electron beam process, always using the same welding parameters. Different materials, on the other hand, require different welding parameters that were not possible with the previously used processes. To line sections 12, 16 and that

To connect the resistance element 20 to one another, a single welding process is therefore used, in which the welding parameters (energy, pressure, time, etc.) can be individually adapted to the respective weld connection.

In the embodiment shown in FIG. 2, the longitudinal axis 32 of the first line section 12 runs parallel to the longitudinal axis 34 of the resistance element 20. The longitudinal axis 36 of the second line section 16 runs perpendicular to the longitudinal axis 34 of the resistance element 20. As a result, the battery sensor 10 is very compact, so that this can be used, for example, in the Polish of a vehicle battery.

In order to additionally increase the strength of the resistance module, it is possible to supplement the measures described above

the longitudinal axis 34 of the resistance element 20 is angled both to the longitudinal axis 32 of the first line section 12 and to the longitudinal axis 36 of the second line section 16 (FIG. 4). The angle 42 between the The longitudinal axis 32 of the first line section 12 and the longitudinal axis 34 of the resistance element 20 is approximately 145 ° in the embodiment shown here. The angle 44 between the longitudinal axis 36 of the second line section 16 and the longitudinal axis 34 of the resistance element 20 is approximately 125 ° in the embodiment shown here

The angle between the second line section 16 and the resistance element 20 makes the inner corner 38 significantly less strong, so that there are significantly lower tensions, in particular notch tensions, on the inner corner 38 due to tensile forces 40 which act on the second line section 16. In addition, the current distribution over the cross section of the resistance element 20 is substantially more homogeneous due to the smaller angle between the second line section 16 and the resistance element 20, so that local heating of the resistance element 20 and the second line section turns out to be significantly less or can even be avoided entirely.

In order to achieve the highest possible stability of the battery sensor 10, the angle by which the longitudinal axis 34 of the resistance element 20 is angled to the longitudinal axis 32, 36 of the line sections 12, 16 is between 30 ° and 60 °, preferably approximately 45 °.

The contact surfaces 24a, 24b are parallel to one another, so that the current path across the resistance element 20 is essentially of the same amount over the entire cross section of the resistance element 20. The joining surfaces 26a, 26b, on the other hand, are each inclined to the longitudinal axis 32, 36 of the line section 12, 16. The bending of the longitudinal axes 32, 36 of the line sections 12, 16 is thus achieved by the inclined joining surfaces 26a, 26b. The joining surfaces 26a, 26b are preferably inclined at an angle 42, 44 of 30 ° to 60 °, in particular at an angle of approximately 45 °.

The angle between the longitudinal axes 32, 36 of the line sections 12, 16 is preferably 90 °, so that the battery sensor 10 described above can be used instead of the battery sensor 10 ′ described in FIGS. 1 and 2 without changing the installation situation on the vehicle battery, in particular the installation situation in a vehicle. In addition, an area 30 can also be provided on the first line section 12, in which the strength of the material of the line section 12 is increased. The line section 12, in particular the battery pole terminal 14, is usually produced in a bending process, for example a stamping and bending process, and must therefore be made of a material with a low bending stiffness. It is therefore not possible to consistently become the first line section 12 from a material that has a high degree of flexural strength. With the measures described above, it is possible to produce the first line section 12 from a material that enables the battery pole terminal 14 to be easily formed, but nevertheless provides a high stability of the resistance assembly 22 and thus of the battery sensor ten.

Reference list

10 battery sensor

12 first line section

14 pole terminal

16 second line section

18 connection

20 resistance element

22 resistor assembly

24a first contact surface

24b second contact surface

26a first joining surface

26b second joining surface

28 housing

30 area

31 plug connection

32 longitudinal axis of the first line section

33a contact points

33b contact points

34 longitudinal axis of the resistance element

36 longitudinal axis of the second line section

38 inside corner

40 tractive forces

42 angle between the longitudinal axis of the first line section and the longitudinal axis of the resistance element

44 between the longitudinal axis of the second line section and the

Longitudinal axis of the resistance element

Claims

1. resistance module (22) for a battery sensor (10), in particular for a vehicle battery, with two line sections (12, 16), a resistance element arranged between the line sections, the line sections (12, 16) each having a joining surface (26a, 26b ) electrically conductive with a contact surface (24a, 24b) of the

Resistance elements (20) are connected, characterized in that at least one line section (12, 16) has increased strength, in particular increased bending stiffness, at least in an area (30) adjoining the joining surface (26a, 26b).

2. Resistor assembly according to claim 1, characterized in that the thickness (D) of the line section (12, 16) is increased at least in the area (30) adjoining the joining surface (26a, 26b).

3. Resistance module according to one of claims 1 and 2, characterized in that the line section (12, 16) in the area (30) adjoining the joining surface (26a, 26b) consists of a material with increased strength, in particular with increased bending stiffness .

4. Resistor assembly according to claim 3, characterized in that the line section (12, 16) in a region (30a) adjoining the joining surface (26a, 26b) has a material with a different chemical composition than in the rest of the line section, in particular a different alloy.

5. Resistor assembly according to claim 3, characterized in that the line section (12, 16) consists of the same material throughout and the strength of the material of the line section (12, 16) in the area (30) adjoining the joining surface (26a, 26b). was increased by an aftertreatment, in particular by a heat treatment or a roller treatment.

6. Resistor assembly according to one of the preceding claims, characterized in that at least one contact surface (24a, 24b) extends at an angle of 30 ° to 60 °, in particular at an angle of 45 °, to the longitudinal axis (34) of the resistance element (20) .

7. Resistor assembly according to one of the preceding claims, characterized in that at least one joining surface (26a, 26b) at an angle of 30 ° to 60 °, in particular at an angle of 45 °, to the longitudinal axis (32, 36) of the line section (12 , 16) runs.

8. Resistor assembly according to one of the preceding claims, characterized in that the longitudinal axis (32, 36) of at least one line section (12, 16) and the longitudinal axis (34) of the

Resistance elements (20) is angled to one another, in particular enclose an angle of at least 45 °, in particular 90 °.

9. Resistor assembly according to one of the preceding claims, characterized in that the longitudinal axes (32, 36) of the

Line sections (12, 16) are angled to one another, in particular at an angle of 90 °.

10. Battery sensor (10), in particular for a vehicle battery, with a resistance module (22) according to one of the preceding claims and with a detection device for detecting a voltage drop across the resistance element (20).

11. A method of manufacturing resistor assembly (22) for one

Battery sensor (10) according to one of Claims 1 to 9, with the following steps:

Providing the line sections (12, 16) and the

Resistance elements (20), at least one line section (12, 16) adjoining a joining surface (26a, 26b) Region (30) has increased strength, in particular increased flexural rigidity,

Align the line sections (12, 16) and the

Resistance elements (20) such that the line sections (12, 16) each have a joining surface (26a, 26b) on a contact surface (24a,

24b) of the resistance element (20),

Material connection of the line sections (12, 16) and the resistance element (at the contact areas, the material connection being carried out by a single welding process.

12. The method according to claim 10, characterized in that the strength of an area adjoining the joining surface (26a, 26b) on at least one line section (12, 16) is increased by a post-treatment.