ELECTRIC CURRENT MEASURING DEVICE WITH IMPROVED INSTALLABILITY

• US 20110050260A1
• Filed: 08/26/2010
• Published: 03/03/2011
• Est. Priority Date: 08/31/2009
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Teramoto, Toshiyo, Nakamura, Shigenobu
• Granted Patent: US 8,680,878 B2
• Time in Patent Office: Days
• US Class Current: 324/705
• CPC Class Codes: G01R 1/203 Resistors used for electric measuring, e.g. decade resistors standards, resistors for comparators, series resistors, shunts resistors in general H01C; microwave or radiowave terminations H01P1/26; coupling devices H01R
• CPC Class Codes: G01R 31/006 on road vehicles, e.g. automobiles or trucks testing of ignition installations peculiar to internal combustion engines F02P17/00
• CPC Class Codes: G01R 31/364 Battery terminal connectors with integrated measuring arrangements
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

In a current measuring device for measuring an electric current flowing through between a terminal of a battery and a wire, a resistance member has a length and first and second ends in a direction of the length. The first end is to be secured electrically to the terminal of the battery. The second end is to be secured electrically to the wire. The resistance member constitutes a current flow path between the terminal of the battery and the wire. The resistance member has a turned portion through which the current flow path extends. The current measuring device includes a circuit board in which a current measuring circuit is installed. The current measuring circuit measures an electric current flowing through the resistance member based on a potential difference between two different points defined on the resistance member.

Claims

1. A current measuring device for measuring an electric current flowing through between a terminal of a battery and a wire, the current measuring device comprising:

a resistance member having a length and first and second ends in a direction of the length, the first end being to be secured electrically to the terminal of the battery, the second end being to be secured electrically to the wire, the resistance member constituting a current flow path between the terminal of the battery and the wire, the resistance member having a turned portion through which the current flow path extends; and

a circuit board in which a current measuring circuit is installed, the current measuring circuit being configured to measure an electric current flowing through the resistance member based on a potential difference between two different points defined on the resistance member.

2. The current measuring device according to claim 1, wherein the resistance member comprises:

a first securement member with the first end to be secured electrically to the terminal of the battery;

a second securement member with the second end to be secured electrically to the wire; and

a resistor having the turned portion and disposed between the first and second securement members, the two different points being defined on the resistor, further comprising;

a resin-molded case located between the first and second securement members, the circuit board being installed in the resin-molded case, at least part of the resistor being embedded in the resin-molded case.

3. The current measuring device according to claim 2, wherein the resistor comprises:

a first resistance portion extending from the first securement member; and

a second resistance portion extending from the second securement member in opposite to the first resistance member,

the turned portion continuously joining the first and second resistance portions and having a substantially U-shape in a direction of the current flow path therethrough.

4. The current measuring device according to claim 2, wherein at least part of the resistor is formed in a wavelike fashion in a direction of the current flow path therethrough.

5. The current measuring device according to claim 3, wherein at least part of the second resistance portion is formed in a wavelike fashion in a direction of the current flow path therethrough.

6. The current measuring device according to claim 2, wherein the resin-molded case is made of a resin having a predetermined level of electrical insulation and a predetermined level of thermal conductivity, the predetermined level of electric insulation being greater than an electric insulation of air, the predetermined level of thermal conductivity being greater than a thermal conductivity of air.

7. The current measuring device according to claim 6, wherein the resin is a PPS (polyphenylene sulfide) resin.

8. The current measuring device according to claim 2, wherein the resistor has a U-shaped turn portion as the turned portion so that the current measuring circuit is configured to measure the electric current flowing through the resistance member based on the potential difference between the two different points defined on the resistance member, the two different points being spaced apart from each other via the U-shaped turn portion, the at least part of the resistor embedded in the resin-molded case containing at least the U-shaped turn portion and the two different points.

9. The current measuring device according to claim 3, wherein the battery has at least a first side surface on which the terminal is mounted and a second side surface being continuous with the first side surface, and each of the first and second resistance portions is so located on any one of the first and second side surfaces of the battery as to extend in a direction parallel to a corresponding one of the first and second side surfaces of the battery.

10. The current measuring device according to claim 3, wherein the battery has at least a first side surface on which the terminal is mounted and a second side surface being continuous with the first side surface, and each of the first and second resistance portions is so located to be opposite to any one of the first and second side surfaces of the battery as to extend in a direction parallel to a corresponding one of the first and second side surfaces of the battery.