HK1153567B - Terminal connection for cylindrical current sense resistor - Google Patents

Description

Terminal connector for cylindrical current sensing resistor

Technical Field

The present invention relates to resistors, particularly in automotive and related applications.

Background

As the amount of electronic devices used in general vehicles has gradually increased in large quantities, the demand for batteries and charging systems of general vehicles has also increased. Furthermore, with the advent of hybrid and all-electric vehicles, batteries and charging systems will become vital components in vehicles. Imperfect electronics systems in today's vehicles can compromise very important functions such as steering and braking.

Therefore, it becomes necessary for the on-board computer to obtain sensed information about the used amount of electricity, the amount of electricity returned, and the amount of available electricity from the overall state of the storage battery and the charging system. The primary sensor for this aspect is a current sensing resistor integrated in the battery cable.

Typically, it is a flat resistor made of a copper nickel manganese alloy resistive element terminated at each end by a brazed copper piece. A copper nickel manganese alloy is an alloy typically composed of 86% copper, 12% manganese and 2% nickel that provides low resistance. The flat resistor will be placed at the end of the cable near the battery connector and surrounded by supporting electronics housed in the canister container. Such resistors may also be used in applications other than automotive applications, such as, but not limited to, galvanic plating power cables, welding cables, and other applications.

Disclosure of Invention

It is therefore a primary object, feature, or advantage of the present invention to improve upon the state of the art.

It is another object, feature, or advantage of the present invention to provide a resistor suitable for use in resistor connection cable applications in automotive and related applications.

It is a further object, feature, or advantage of the present invention to provide a resistor that allows current sensing.

One or more of these and/or other objects, features and advantages of the present invention will become apparent from the following detailed description and claims.

According to one aspect of the invention, a resistor includes a substantially cylindrical resistive element having a resistance of less than 1m Ω, a substantially cylindrical first terminal electrically connected to the resistive element, and a second terminal electrically connected to the resistive element. The substantially cylindrical first terminal is hollow, allowing to accommodate a connector such as a battery cable. There may be one or more sense leads connected to a resistor.

According to another aspect of the invention, a method of manufacturing a substantially cylindrical resistor is provided. The method includes rolling a flat sheet including a resistive element and first and second terminals connected at opposite ends of the resistive element to form a hollow cylindrical resistor body.

According to another aspect of the invention, a method of manufacturing a substantially cylindrical resistor includes providing a first tube for a first terminal, providing a second tube for a second terminal, and welding a resistive element between the first tube and the second tube using electromagnetic pulse welding, thereby providing a substantially cylindrical resistor.

Drawings

Fig. 1 is a perspective view of one embodiment of a cylindrical resistor of the present invention.

Fig. 2 is an exploded perspective view of one embodiment of a cylindrical resistor of the present invention.

FIG. 3 is a perspective view of a cylindrical resistor connected to a battery cable assembly of a vehicle.

Fig. 4 is a perspective view of a cylindrical resistor connected to a battery cable of a vehicle.

Fig. 5 is a schematic diagram of a step of a method of manufacturing a cylindrical resistor according to one embodiment of the invention.

Fig. 6 is a schematic diagram of a step of a method of manufacturing a cylindrical resistor according to one embodiment of the invention.

Fig. 7 is a schematic diagram of a step of a method of manufacturing a cylindrical resistor according to one embodiment of the invention.

Detailed Description

The present invention generally relates to a cylindrical resistor and a method of manufacturing the same. The cylindrical resistor is used in applications such as, but not limited to, automotive applications, galvanic plating power cables, welding cables, and other applications. The cylindrical shape enables the resistor to be integrated within the cable assembly in a more space efficient manner, and enables plugging at any location along the length of the cable. The flexibility in location enables the support electronics to also be placed closer to other electronic modules or at battery terminals.

Fig. 1 shows a perspective view of one embodiment of a cylindrical resistor 10. The cylindrical resistor 10 comprises a resistive element 12. The resistive element 12 may be made of a cylindrical copper nickel manganese wire or other suitable resistive material. Each end of the resistive material is terminated with copper or another suitable conductive material to form the terminals 14, 16 of the resistor 10. Terminals 14, 16 may be used to connect resistor 10 with the cable assembly and to carry the main current. These terminals 14, 16 are connected to the resistance element 12 by welding, soldering or crimping. The terminals 14, 16 can be connected to the battery cable assembly by welding, soldering or crimping. The geometry of these terminations varies based on the particular application for the cylindrical resistor application, and the present invention is not limited by the particular dimensions of the terminations shown.

Integrated as an accessory to these terminals are one or more sensing leads 22, 24 connected to the terminals 14, 16. These sense leads 22, 24 are used to connect to support electronics that require a sense voltage input that is proportional to the current flowing through the resistor 10. These leads 22, 24 may be extensions of the resistor termination material or otherwise added, such as by welding, soldering, crimping or other means. The particular geometry of these sense leads may vary depending on the particular application and environment, and the invention is not limited by the particular geometry illustrated.

In one embodiment, the components of the shunt resistor 10 are comprised of copper tubing for the terminals 14, 16 and a length of substantially cylindrical copper nickel manganese resistance wire for the resistive element 12. The resistance wire is cut into small segments. One end of a small section of resistance wire is placed in the end of a copper tube, and the two ends are joined together by electromagnetic pulse welding which causes the copper tube to collapse uniformly onto the resistance wire at a rate which causes a weld to be formed. The other end of the copper nickel manganese wire resistive element is inserted into the end of another copper tube and connected by another magnetic pulse. Thus, a resistor such as resistor 10 shown in fig. 1 is formed.

The amount of unwelded resistor material between the ends of the two copper tubes determines the resistance of the blank. The adjustment of the resistance value may be accomplished by lathe machining, grinding or laser operations that reduce the diameter of the exposed copper nickel manganese wire or by removing copper from the end of each tube that effectively extends the copper nickel manganese resistance element. In addition, the resistance is adjusted by adding a terminal material (such as copper or other conductive material) to the resistive element, such as by soldering. Here the open ends of the copper tubes are ready to receive further processing steps to connect them to the cable assembly. Such as inserting the cable 34 into the open tube and welding the two pieces together by magnetic pulse welding, as shown in fig. 4. This joint may also be achieved by soldering, crimping, brazing or other welding methods. A battery terminal clip 30 having an end 32 can also be inserted into an open tube end and secured in place as shown in fig. 3. The battery terminal clip may also be secured by soldering, crimping, brazing, or other welding methods.

Fig. 5 and 6 show another embodiment of a cylindrical resistor. In this embodiment, the resistor utilizes a flat resistive element made of a copper nickel manganese material or other suitable resistive material, with terminals of copper or other suitable conductive material being welded to each end of the resistive material in the same manner as used to make the energy metal strip resistor disclosed in U.S. patent No.5604477, which is incorporated herein by reference in its entirety.

In fig. 5, a flat sheet 39 is illustrated. The flat sheet 39 includes a resistive material 42 and a termination material 40. The termination material includes a first portion 40A and a second portion 40B on opposite sides of the resistive material 42. The sense leads 22 are electrically connected to and extend from a first portion 40A of the termination material 40, while the sense leads 24 are electrically connected to and extend from a second portion 40B of the termination material 40.

The flat sheet 39 is rolled into a cylinder and the resistive material 42 becomes a ribbon that is bent around the circumference of the cylinder, as best shown in fig. 6. The resistive material 42 and the termination material 40 have holes or slots 46 in designated areas to facilitate the aforementioned coil forming process and to facilitate crimping to the cable. These slots 46 may also be used to adjust the resistance value and TCR. The material from these slots 46 can be separated from the body on three sides, leaving only the fourth side connected, thus constituting a sensing terminal integral with the resistive material.

In another embodiment, as shown in fig. 7, the resistor is configured such that one terminal 40A is cylindrical for connection to a cable, while the second terminal 40B has a flat terminal 48 with a hole 50. The flat terminals 48 may be connected to battery terminals or other post-mount connectors.

It is noted that when the cylindrical resistor is hollow, the resistive element may be cooled by a fluid circulating therethrough. Such cooling may be desirable in certain circumstances.

The barrel resistor of the present invention has a resistance value of less than 1m omega and is designed to handle currents of 200A and above. Therefore, the barrel resistor can be well suited for automotive use, battery monitoring use, and related uses requiring low electrical resistance.

Therefore, a barrel resistor has been disclosed. The present invention contemplates variations in size, shape, materials used, electrical resistance, and other variations. While various embodiments have been illustrated and described, the invention is not limited to the specific embodiments shown.

Claims (15)

1. A resistor for axial connection to a cable, the resistor comprising:

a resistive element disposed between a first terminal and a second terminal, wherein the resistive element, the first terminal and the second terminal are formed from a flat sheet rolled into a substantially cylindrical hollow resistor body, the resistive material forming a band that curves around a circumference of the resistor body, and wherein at least the first terminal forms a conductive tube for axial connection to a cable.

2. The resistor of claim 1 further comprising a first sense lead electrically connected to the first terminal and a second sense lead electrically connected to the second terminal.

3. The resistor of claim 1 including at least one slot formed in the first terminal to define the sense terminal.

4. The resistor of claim 1 further comprising at least one slot in the resistive element or in the first terminal to facilitate roll forming.

5. The resistor of claim 1 wherein the resistive element is a metal strip.

6. The resistor of claim 1 wherein the first terminal comprises a first conductive tube and the second terminal comprises a second conductive tube.

7. The resistor of claim 1 wherein the resistive element is magnetically pulse welded to the first and second terminals to provide a substantially cylindrical resistor for axial connection to a cable.

8. The resistor of claim 1 wherein the second terminal comprises a flattened terminal region.

9. The resistor of claim 1 wherein a fluid or gas is circulated through the resistor to control the temperature of the resistive element.

10. A method of forming a resistor for axial connection to a cable, the method comprising:

providing a resistive element between a first terminal and a second terminal, wherein the resistive element, the first terminal and the second terminal are formed from a flat sheet; and

the flat sheet is wound to form a substantially cylindrical hollow resistor body, wherein the resistive material forms a band that is bent around the circumference of the resistor body, and at least a first terminal forms a conductive tube for axial connection to an electrical cable.

11. The method of claim 10, wherein the resistance of the resistive element is less than 1m Ω.

12. The method of claim 10, further comprising adjusting the resistance of the resistor by cutting the resistive element or adding material to the body of the resistor.

13. The method of claim 12, wherein the material is an additional resistive material or an additional termination material.

14. The method of claim 10, further comprising cutting a slot in the flat sheet to facilitate winding.

15. The method of claim 10, further comprising connecting the sense leads to a resistor body.