System and method for independently controlling relay, using bimetal

• US 10,446,352 B2
• Filed: 08/30/2016
• Issued: 10/15/2019
• Est. Priority Date: 11/17/2015
• Status: Active Grant

• Current Assignee: LG Energy Solution Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Song, Hyeon Jin, Choi, Yanglim
• Primary Examiner(s): Vortman, Anatoly
• Assistant Examiner(s): Sul, Stephen S
• Application Number:
  US15/576,961
• Publication Number:
  US 20180151319A1
• Time in Patent Office: 1,141 Days
• Field of Search: 337105, 337333, 337334
• CPC Class Codes: B60R 16/03 for supply of electrical power to vehicle subsystems or for circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: G01R 19/0092 measuring current only all subgroups of G01R19/00 take precedence
• CPC Class Codes: H01H 37/00 Thermally-actuated switches
• CPC Class Codes: H01H 37/52 actuated due to deflection of bimetallic element
• CPC Class Codes: H01H 37/54 wherein the bimetallic element is inherently snap acting
• CPC Class Codes: H01H 47/002 Monitoring or fail-safe circuits
• CPC Class Codes: H01H 61/00 Electrothermal relays thermal switches not operated by electrical input, thermal switches with anticipating electrical input H01H37/00; thermally-sensitive members H01H37/32
• CPC Class Codes: H01H 61/013 Heating arrangements for operating relays
• CPC Class Codes: H01H 61/02 wherein the thermally-sensitive member is heated indirectly, e.g. resistively, inductively
• CPC Class Codes: H01H 61/04 wherein the thermally-sensitive member is only heated directly
• CPC Class Codes: H01H 61/063 making use of a bimetallic element
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/00304 Overcurrent protection

Abstract

The present invention relates to a system and a method for independently controlling a relay using bimetal which allow bimetal to operate based on a signal output from a micro controller unit when current of a predetermined threshold or more flows on a circuit to allow current which flows between a battery and the relay to flow bypassing the bimetal to independently control the relay regardless of whether a circuit pattern is abnormal.

Claims

1. A system for independently controlling a relay in a circuit, the system comprising:

a micro controller unit (MCU) configured to output a signal when a current value on the circuit is more than a predetermined threshold;

a signal inversion unit configured to;

receive the signal directly from the MCU, and

invert and amplify the signal output from the MCU; and

a switching unit configured to;

receive the inverted and amplified signal directly from the signal inversion unit, and

apply a specific current directly to a bimetal unit based on the signal output from the signal inversion unit,

wherein the bimetal unit is configured to receive the specific current directly from the switching unit and is connected with the relay provided in the circuit,

wherein the bimetal unit includes;

a heating unit generating heat by the specific current, and

a bimetal, the bimetal being configured to be bent in one direction by the heat,

wherein the heating unit is directly connected with the bimetal,

wherein the system further comprises a fuse unit provided between the bimetal unit and the relay and having an inner part configured to be disconnected by the heat generated from the heating unit, and

wherein the MCU outputs the signal, the bimetal unit is shape-transformed by the specific current applied from the switching unit to change a state of the relay from an on state to an off state to reduce a magnetic force of a relay coil of the relay and to block current flowing from a battery to the relay.

2. The system of claim 1, wherein when the bimetal is bent in one direction, one terminal portion of the bimetal contacts a contact of the circuit and the specific current on the circuit is applied to one terminal portion of the bimetal.

3. The system of claim 2, wherein when the specific current on the circuit is applied to the bimetal, a current amount applied to the relay is reduced in the circuit to change the state of the relay from the on state to the off state.

4. The system of claim 1, wherein the signal inversion unit inverts a low signal output from the MCU into a high signal.

5. The system of claim 1, wherein the switching unit is a field effect transistor (FET).

6. The system of claim 1, further comprising:

a current measurement unit measuring the current value on the circuit and providing the measured current value to the MCU.

7. The system of claim 6, wherein the MCU outputs the signal when the current value provided from the current measurement unit is more than the predetermined threshold.

8. The system of claim 6, wherein the current measurement unit is a shunt resistor.

9. The system of claim 1, wherein when the inner part of the fuse unit is disconnected by the heat, the specific current applied to the relay is blocked in the circuit.

10. A method for independently controlling a relay in a circuit, the method comprising:

outputting, by a micro controller unit (MCU), a signal when a current value on the circuit is more than a predetermined threshold, wherein the signal is output directly to a signal inversion unit;

the signal inversion unit inverting and amplifying the signal output from the MCU and outputting the inverted and amplified signal directly to a switching unit; and

applying, by the switching unit, a specific current directly to a bimetal unit to shape-transform the bimetal unit,

wherein the shape-transforming of the bimetal unit changes a state of the relay from an on state to an off state to reduce a magnetic force of a relay coil of the relay and to block current flowing from a battery to the relay,

wherein the shape-transforming of the bimetal unit includes;

generating, by a bimetal unit of the bimetal unit, heat by the specific current,

bending bimetal of the bimetal unit in one direction by the heat, and

applying the specific current on the circuit to one terminal portion of the bimetal as the one terminal portion of the bimetal contacts a contact of the circuit,

wherein the heating unit is directly connected with the bimetal,

wherein the circuit is further disconnected by a fuse unit that is connected with the heating unit and provided between the bimetal unit and the relay, and

wherein an inner part of the fuse unit is disconnected by the heat generated from the heating unit.

11. The method of claim 10, wherein the inverting of the signal includes inverting, by the signal inversion unit, a low signal output from the MCU into a high signal.

12. The method of claim 10, wherein the applying of the specific current on the circuit includes changing the state of the relay from the on state to the off state as a current amount applied to the relay is reduced in the circuit.

13. The method of claim 10, further comprising:

measuring, by a current measurement unit, the current value on the circuit and providing the measured current value to the MCU.

14. The method of claim 13, wherein the outputting of the signal when the current value on the circuit is more than a predetermined threshold includes outputting, by the MCU, the signal when the current value provided from the current measurement unit is more than the predetermined threshold.