Current interruption device and electric storage device using same

Patent metadata

Field	Value
Publication number	US-10020146-B2
Application number	US-201314391983-A
Country	US
Kind code	B2
Filing date	Apr 11, 2013
Priority date	Apr 12, 2012
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

A current interruption device includes: a deforming plate configured to deform when the internal pressure of the casing rises above the predetermined level; a conducting plate which configures the current path; and a contact plate. The conducting plate includes a first contact portion configured to contact the contact plate. The contact plate includes a second contact portion configured to contact the first contact portion. The deforming plate includes a pressure receiving portion configured to receive the internal pressure of the casing and a contacting portion configured to contact the first contact portion. The second contact portion is configured to be separated from the conducting plate by deformation causing the contacting portion to move toward the contact plate. The deforming plate is insulated from the conducting plate and the contact plate. The conducting plate is disposed to be interleaved between the deforming plate and the contact plate.

First claim

The invention claimed is:

1. A current interruption device configured to electrically connect a positive electrode external terminal extending through a hole formed on a casing and an electrode assembly comprising a positive electrode and a negative electrode, or to connect a negative electrode external terminal extending through another hole formed on the casing and the electrode assembly, and to interrupt a current path of the positive electrode external terminal and the electrode assembly, or a current path of the negative electrode external terminal and the electrode assembly, when an internal pressure of an internal casing space accommodating the electrode assembly rises above a predetermined level, the current interruption device being disposed in the internal casing space, the current interruption device comprising:
a deforming plate configured to deform when the internal pressure of the internal casing space rises above the predetermined level;
a conducting plate which configures the current path; and
a contact plate, wherein the contact plate is a diaphragm,
wherein the conducting plate includes a first contact portion configured to contact the contact plate,
the contact plate includes a second contact portion configured to contact the first contact portion,
the first contact portion and the second contact portion are disposed on the current path,
the deforming plate includes a pressure receiving portion configured to receive the internal pressure of the internal casing space and a contacting portion configured to contact at least one of the first contact portion and the second contact portion,
the first contact portion and the second contact portion are configured to be separated from the conducting plate by deformation of the deforming plate causing the contacting portion to move toward the contact plate,
the first contact portion and the second contact portion overlap and contact each other at a center portion of the current interruption device, in a direction perpendicular to the conducting plate, both before and after the first contact portion and the second contact portion are separated from the conducting plate,
the deforming plate is insulated from at least one of the conducting plate and the contact plate and disposed such that the deforming plate configures an outer face of the current interruption device to isolate the conducting plate and the contact plate from a space portion where the electrode assembly is accommodated which is outside of the current interruption device in the internal casing space, and
the conducting plate is disposed to be interleaved between the deforming plate and the contact plate.

2. The current interruption device according to claim 1 , wherein
the first contact portion is disposed at a center portion of the conducting plate and the second contact portion is disposed at a center portion of the contact plate.

3. The current interruption device according to claim 1 , wherein a projection projecting toward the contact plate is disposed at a center portion of the deforming plate, and the contacting portion is included in the projection.

4. The current interruption device according to claim 3 , wherein
the current interruption device is configured to shift among a first condition, a second condition and a third condition,
in the first condition a gap is provided between the deforming plate and the conducting plate during when the internal pressure of the casing is below the predetermined level,
in the second condition the contact plate is separated from the conducting plate by the projection of the deforming plate moving toward the conducting plate and adding an impact to the contact plate when the internal pressure of the casing rises above the predetermined level,
in the third condition a force of the contact plate moving toward the conducting plate and a force of the deforming plate separating the contact plate from the conducting plate are balanced, and
in the third condition the contact plate is separated from the conducting plate so as not to conduct with the conducting plate.

5. The current interruption device according to claim 3 , further comprising:
an insulating cap covering the projection.

6. The current interruption device according to claim 5 , wherein the cap includes a guide portion that is supported with an outer circumference portion of the conducting plate.

7. The current interruption device according to claim 5 , wherein
a groove surrounds an entire periphery of a portion with which the contacting portion makes contact, and
an area surrounded by the groove is recessed relative to a surface of the conducting plate on an outer side of the groove.

8. The current interruption device according to claim 1 , wherein
a groove is disposed around a center portion of the conducting plate around a portion with which the contacting portion is to make contact.

9. The current interruption device according to claim 8 , wherein
the deforming plate is an inverting plate, and
an elastic force that inverts the deforming plate is larger than a force that breaks the groove of the conducting plate.

10. The current interruption device according to claim 8 , wherein
an area surrounded by the groove of the conducting plate is recessed toward an opposite side of the deforming plate than a surface positioned at an outer side of the groove of the conducting plate.

11. The current interruption device according to claim 1 , further comprising:
an insulating member having an insulation property disposed between the deforming plate and the conducting plate.

12. The current interruption device according to claim 1 , wherein
a recess is disposed at a center portion of the conducting plate on a deforming plate side.

13. The current interruption device according to claim 1 , wherein
a fragile portion is disposed around the second contact portion of the contact plate, the fragile portion being more fragile than other portions of the contact plate.

14. The current interruption device according to claim 13 , wherein
an interspacing portion is disposed between an outer circumference portion of the contact plate and the second contact portion, a distance from the interspacing portion to the conducting plate being increased from the outer circumference portion toward a center portion of the contact plate, and
the fragile portion is disposed on the interspacing portion.

15. The current interruption device according to claim 1 , wherein
a periphery of the first contact portion on a surface of the conducting plate on a contact plate side is recessed.

16. The current interruption device according to claim 1 , wherein
the deforming plate and the contact plate are configured by thin plates.

17. The current interruption device according to claim 16 , wherein
the deforming plate is configured by a thin plate having an arc-shaped wavy portion, and
the contact plate is configured by a flat thin plate.

18. The current interruption device according to claim 16 , wherein
the deforming plate is configured by a flat thin plate, and
the contact plate is configured by a thin plate having an arc-shaped wavy portion.

19. The current interruption device according to claim 1 , wherein
a through-hole configured to allow the contacting portion to pass through is disposed at a center portion of the conducting plate.

20. The current interruption device according to claim 1 , wherein
a pressure hole configured to exert a pressure change caused by the deformation

Assignees

• Toyota Jidoshokki Kk
• Eagle Ind Co Ltd

Inventors

• Okuda Motoaki
• Umemura Satoshi
• Kato Takayuki
• Nishihara Hiroyasu
• MINAGATA Atsushi
• Akiyama Hirokuni
• Odagiri Toshio
• Hirose Takayuki
• Ogawa Yoshihiro
• Iwa Toshiaki

Classifications

• H01M50/55

  on the same side of the cell · CPC title

• Y02E60/13

  Energy storage using capacitors · CPC title

• H01H35/346 Primary

  in which the movable contact is formed or directly supported by the diaphragm · CPC title

• H01M2/345

  Electricity · mapped topic

• H01G2/14 Primary

  Protection against electric or thermal overload (by cooling H01G2/08) · CPC title