JP2001023596A - Explosion-proof construction of secondary battery - Google Patents
Explosion-proof construction of secondary batteryInfo
- Publication number
- JP2001023596A JP2001023596A JP11196137A JP19613799A JP2001023596A JP 2001023596 A JP2001023596 A JP 2001023596A JP 11196137 A JP11196137 A JP 11196137A JP 19613799 A JP19613799 A JP 19613799A JP 2001023596 A JP2001023596 A JP 2001023596A
- Authority
- JP
- Japan
- Prior art keywords
- explosion
- pressure
- thickness
- safety valve
- secondary battery
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
- Y02E60/10—Energy storage using batteries
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、電解液を外気と
隔離した密閉形の二次電池の防爆構造に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an explosion-proof structure for a sealed secondary battery in which an electrolyte is isolated from the outside air.
【０００２】[0002]
【従来の技術】充放電を繰り返して反復使用できる二次
電池が近年では携帯電話のような小型機器等に広く使用
されるようになっている。二次電池の種類は大別すると
アルカリ蓄電池、鉛蓄電池、あるいは有機電解液電池
（非水電解質電池）であるリチウム電池などがあるが、
特にリチウム電池は比較的新しいタイプの二次電池とし
て注目されている。2. Description of the Related Art In recent years, secondary batteries that can be repeatedly used by repeating charging and discharging have been widely used for small devices such as mobile phones. The types of secondary batteries are roughly classified into alkaline storage batteries, lead storage batteries, and lithium batteries that are organic electrolyte batteries (non-aqueous electrolyte batteries).
In particular, lithium batteries are attracting attention as relatively new types of secondary batteries.
【０００３】上記リチウム電池のような有機電解液を外
気と隔離した密閉形の二次電池は通常以上の電流供給に
よる過充電状態あるいは誤使用による短絡状態で大電流
が流れたりすると電解液が急速に分解されてガスが発生
し、このガスが電池内に充満して大きな内圧が生じ、場
合によっては爆発することもある。このような内圧によ
る爆発を防止するため、従来より密閉形の二次電池の外
装缶の上端部側に防爆用の安全弁装置を設けたものが、
例えば特開平２−１１２１５１号公報により知られてい
る。In a sealed secondary battery such as the above-mentioned lithium battery, in which an organic electrolyte is isolated from the outside air, when a large current flows in an overcharged state due to a supply of a current higher than usual or a short-circuited state due to misuse, the electrolyte rapidly increases. The gas is decomposed to generate gas, which fills the inside of the battery and generates a large internal pressure, and in some cases, explodes. In order to prevent such an explosion due to internal pressure, a safety valve device for explosion proof has been provided on the upper end side of the outer can of a sealed secondary battery conventionally.
For example, it is known from JP-A-2-112151.
【０００４】この特開平２−１１２１５１号公報の電池
外装缶の上端部側に設けた安全弁装置の構成は、円形状
の防爆弁の中央から放射状に溝を設けた薄肉部とした
り、防爆弁の中央に小さな薄肉部を設けたもの、あるい
は上端の皿状端子板の内側に設けた突状の切断刃を設け
端子板より内側寄りに設けた薄肉部が内圧で外側へ湾曲
すると切断刃で突き破る形状のものが示されている。The structure of the safety valve device provided on the upper end side of the battery outer can disclosed in Japanese Patent Application Laid-Open No. 2-112151 is a thin-walled portion provided with a groove radially from the center of a circular explosion-proof valve, or a structure of the explosion-proof valve. With a small thin part in the center, or a protruding cutting blade provided inside the dish-shaped terminal plate at the upper end, and the thin part provided closer to the inside than the terminal plate is broken by the cutting blade when it curves outward due to internal pressure Shaped ones are shown.
【０００５】又、他の形式の防爆構造を有するものとし
て、金属製電池缶の底部に切欠を施したものが、例えば
特開平１−３０９２５２号公報、あるいは特開平１−３
０９２５３号公報により開示されている。この２つの公
報の防爆構造は、電池缶の底板の内、外面に幅の広い浅
い溝とＶ字断面の溝を設けたものから成る。As another type of explosion-proof structure, a metal battery can with a cutout at the bottom is disclosed in, for example, JP-A-1-309252 or JP-A-1-3253.
No. 09253. The explosion-proof structures disclosed in these two publications have a structure in which a wide shallow groove and a groove having a V-shaped cross section are provided on the outer surface of a bottom plate of a battery can.
【０００６】[0006]
【発明が解決しようとする課題】しかし、上述した第１
の公報による安全弁装置の防爆構造は、電池内の異常反
応で内圧が大きくなり爆発する虞れが生じると安全弁を
破裂させて防爆するというだけであって、内圧がどれ位
いであれば安全弁が破裂するのか、又安全弁が必らず設
定した圧力で作動するようにして安全弁の作動の安定化
を図ることについては一切言及されていない。However, the above-described first method
The explosion-proof structure of the safety valve device according to the publication discloses that when the internal pressure increases due to an abnormal reaction in the battery and there is a risk of explosion, the safety valve is only ruptured to prevent the explosion. No mention is made of how to operate the safety valve at a set pressure to stabilize the operation of the safety valve.
【０００７】一方、第２、第３の公報による防爆構造
は、その切欠溝の構造によって電池缶部に安定した防爆
機能を発揮させることをねらったものであり、その従来
技術の欄で従来の二次電池の防爆構造では安定した切裂
開放圧力が得られないことについて言及している。又、
防爆用切欠を形成するのに用いられるプレス加工では、
ステンレススチール缶の場合、溝部が加工硬化を起し、
焼鈍しなければ防爆機能の作動圧力が安定しない。さら
に溝部を鋭利なＶ字状にすると切裂しやすいが、加工の
ためのパンチの耐久性が低く、溝部底部に小さな丸みを
設けると圧力上昇に鋭敏でなくなる旨述べている。On the other hand, the explosion-proof structures according to the second and third publications aim at exerting a stable explosion-proof function on the battery can part by the structure of the notched grooves. It mentions that the explosion-proof structure of the secondary battery does not provide a stable tear opening pressure. or,
In the press working used to form the explosion-proof notch,
In the case of stainless steel cans, the grooves cause work hardening,
Without annealing, the working pressure of the explosion-proof function will not be stable. Furthermore, it is described that if the groove is formed in a sharp V-shape, the cut is easy to be cut, but the durability of the punch for processing is low, and if a small roundness is provided at the bottom of the groove, the groove becomes less sensitive to pressure rise.
【０００８】しかし、上記第２、第３の公報による防爆
構造は、底板の内、外両面に切欠溝を設け、かつこれら
の切欠溝を直線部と分岐部の組合わせとしたものであ
り、直線部に対し分岐部をＶ字状又は半円形状とし分岐
部との協働作用で直線部での切裂作用を所定圧に設定で
きるとしているが、実際にはその切裂圧は１５〜４５ｋ
ｇ／ｃｍ2 の範囲で一定せず、かつ切裂圧が高いため設
定圧以上の圧力で切裂すると必らずしも安全ではない。However, the explosion-proof structures according to the second and third publications have cutout grooves provided on both inside and outside surfaces of the bottom plate, and these cutout grooves are formed by combining a straight portion and a branch portion. The branch portion is formed in a V-shape or semicircular shape with respect to the straight portion, and the tearing action in the straight portion can be set to a predetermined pressure by cooperation with the branch portion. 45k
g / cm 2 is not constant, and the tearing pressure is high, so it is not necessarily safe to tear at a pressure higher than the set pressure.
【０００９】又、内、外両面の切欠溝を設けたことによ
りその切欠溝部に残る残厚ｔは実際には３０μｍ程の極
薄いものとなっているが、このような薄い残厚を有する
切欠溝部を設けると、例えば電池を使用中に誤って落し
たりした際の衝撃が加えられると、内圧による作用でな
く落下による衝撃で破断し安全弁としての作用を失って
しまう可能性があり実用上このような切欠溝を設けるこ
とは信頼性の観点から疑問がある。[0009] Further, since the notch grooves on both the inner and outer surfaces are provided, the remaining thickness t remaining in the notch grooves is actually as extremely thin as about 30 µm. If a groove is provided, for example, if an impact is applied when the battery is accidentally dropped during use, the battery may be broken not by the action of the internal pressure but by the impact of the fall and lose the action as a safety valve. It is questionable to provide such a notch groove from the viewpoint of reliability.
【００１０】この発明は、上述した従来の二次電池の防
爆構造における種々の問題に留意して、二次電池の上端
の封口板又は下底板に低い設定圧で安全に高い精度で確
実に作動するように設定し、かつ耐衝撃強度も確保した
安全弁を設けて二次電池の防爆構造を得ることを課題と
する。The present invention takes into account the various problems in the conventional explosion-proof structure of a secondary battery described above, and operates safely and with high accuracy at a low set pressure on a sealing plate or a lower bottom plate at the upper end of the secondary battery. It is an object to obtain an explosion-proof structure of a secondary battery by providing a safety valve which is set so as to have a high impact resistance.
【００１１】[0011]
【課題を解決するための手段】この発明は、上記課題を
解決する手段として、発電要素を収容する電池外装缶の
上端部の封口板又は底板に内圧で変形する切欠き溝を有
する安全弁を設けた二次電池において、上記安全弁部位
の板素材に基礎残厚が残るように平板状凹部を形成し、
この凹部に基礎残厚から板素材厚の半分又はそれ以下の
厚さを滅じた厚さで、かつ防爆圧に所定の圧力を加えた
圧力で切裂する第２残厚が残るように切欠溝を形成し、
上記切欠溝に溝面が屈曲した屈曲断面部を形成してその
第３残厚が大気圧により大きい防爆圧以上の内圧で切裂
する残厚となるようにした二次電池の防爆構造としたの
である。According to the present invention, as a means for solving the above-mentioned problems, a safety valve having a notch groove which is deformed by internal pressure is provided in a sealing plate or a bottom plate at an upper end of a battery outer can housing a power generating element. In the secondary battery, a flat concave portion is formed so that a basic residual thickness remains in the plate material at the safety valve portion,
Notch in this recess so that a second remaining thickness that is cut by a pressure obtained by applying a predetermined pressure to the explosion-proof pressure remains at a thickness obtained by subtracting half or less of the thickness of the sheet material from the basic remaining thickness. Forming a groove,
An explosion-proof structure of a secondary battery in which a bent cross-section in which a groove surface is bent is formed in the notch groove so that the third remaining thickness has a thickness that is cut by an internal pressure equal to or greater than the atmospheric pressure and equal to or greater than the explosion-proof pressure. It is.
【００１２】上記構成の二次電池は異常な大電流の充電
などが行なわれて外装缶内に内圧が生じても安定した低
い圧力で確実に安全に作動し、かつ耐衝撃作用に対して
構造強度が十分なものが得られる。[0012] The secondary battery having the above-described structure operates reliably and stably at a stable low pressure even when an internal pressure is generated in the outer can due to charging of an abnormally large current or the like, and has a structure that is resistant to impact. One with sufficient strength can be obtained.
【００１３】安全弁構造は、封口板の平板状凹部に設け
た切欠溝位置に形成した屈曲断面部の第３残厚を防爆圧
で直ちに作動し得る程の薄い残厚としたから、外装缶内
に大気圧より大きい防爆圧以上の内圧が生じると屈曲断
面部で容易に切裂する。防爆圧は第３残厚の限界厚さと
の関係で設定し得る最小圧力として設定され、例えば数
ｋｇ／ｃｍ2 程度の低い圧力である。In the safety valve structure, the third remaining thickness of the bent cross section formed at the position of the cutout groove provided in the flat recess of the sealing plate is made thin enough to be able to be operated immediately by explosion-proof pressure. When an internal pressure equal to or higher than the explosion-proof pressure is generated, it easily tears at the bent cross section. The explosion-proof pressure is set as a minimum pressure that can be set in relation to the limit thickness of the third remaining thickness, and is a low pressure of, for example, about several kg / cm 2 .
【００１４】このように低い防爆圧に対応する薄い第３
残厚の屈曲断面部は残厚が極めて薄いけれど、断面が屈
曲状とされているため、二次電池を誤って落下させた際
の衝撃が作用しても破断せず構造強度が大きい。このよ
うな屈曲断面部を切欠溝位置に形成することにより安全
弁としての作動圧を低くし、かつ耐衝撃作用に対する構
造強度の強化という相反する条件を満足させている。The thin third layer corresponding to such a low explosion-proof pressure
Although the remaining cross section is extremely thin, the cross section is bent, so that it does not break even if an impact is applied when the secondary battery is dropped by mistake, and the structural strength is large. By forming such a bent cross-section at the position of the notch groove, the opposing conditions of reducing the operating pressure as a safety valve and enhancing the structural strength against impact resistance are satisfied.
【００１５】[0015]
【実施の形態】以下、この発明の実施形態について図面
を参照して説明する。図１は実施形態の電池の概略断面
図を示す。図示の電池は角形電池のものであるが、円形
断面のものにも以下の構成は同様に適用される。但し、
図示の例では内装される発電要素及びその接続金具の詳
細は図示省略している。下底板１ｂを含む外装缶１に
は、その内部に発電要素２が収容され、上端が封口板１
ａにより図（ａ）、（ｂ）のいずれかの密封形状で閉じ
られている。封口板１ａの中央には電極部３が設けら
れ、その外側に安全弁４が設けられている。電極部３は
ガスケット３ａにより封口板１ａと絶縁、密封されてい
る。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic cross-sectional view of the battery of the embodiment. Although the illustrated battery is a square battery, the following configuration is similarly applied to a battery having a circular cross section. However,
In the example shown in the figure, the details of the power generation elements and the connection fittings to be installed are not shown. A power generation element 2 is accommodated in an outer can 1 including a lower bottom plate 1b, and an upper end thereof is a sealing plate 1
By a, it is closed in one of the sealed shapes shown in FIGS. An electrode portion 3 is provided at the center of the sealing plate 1a, and a safety valve 4 is provided outside the electrode portion 3. The electrode part 3 is insulated and sealed from the sealing plate 1a by a gasket 3a.
【００１６】安全弁４の拡大形状を図２に示す。この安
全弁４は、安全弁の板素材の厚さＴから３段のプレス加
工処理を経て得られる３種類の厚さｔ1 〜ｔ3 の構成部
分である第１〜第３加工部分４ａ〜４ｃから成る。特
に、第２加工部分４ｂのフラットな押圧部分の一部に切
欠溝を設けた部分の残厚ｔ2 を残厚ｔ3 よりやや厚くし
ておき、第３加工部分４ｃを切欠溝の加工面側に突出し
て屈曲した屈曲断面部としている。FIG. 2 shows an enlarged shape of the safety valve 4. The safety valve 4, from the first to third processing portion 4a~4c are three components of the thickness t 1 ~t 3 obtained through the pressing process in three stages from the thickness T of the safety valve plate material Become. In particular, leave a residual thickness t 2 of a portion in the cut groove provided portion of the flat pressing portion of the second working portion 4b slightly thicker than the remaining thickness t 3, the machined surface of the cutout grooves of the third machining portion 4c It has a bent cross-section that protrudes to the side and is bent.
【００１７】上記屈曲加工により残厚ｔ2 よりさらに薄
くなったその残厚ｔ3 は大気圧以上の内圧で直ちに切裂
する厚さである。この大気圧以上の内圧は防爆圧と呼ば
れ、この実施形態では従来の例よりはるかに低く、理論
的には大気圧以上であればよいが、実際には極く薄い残
厚ｔ3 の限界厚さ（２０μｍ）に関連して約５ｋｇｆ／
ｃｍ2 程度とされる。又、このような内圧に対して設定
される残厚ｔ3 は２０〜３０μｍである。The remaining thickness t 3, which is made thinner than the remaining thickness t 2 by the bending, is a thickness that is immediately torn at an internal pressure higher than the atmospheric pressure. The more pressure atmospheric pressure is referred to as anti爆圧, the much lower than the conventional examples this embodiment, in theory may be equal to or greater than atmospheric pressure, in fact, limit the extremely thin residual thickness t 3 About 5kgf /
cm 2 . Further, the remaining thickness t 3 when set for such pressure is 20 to 30 [mu] m.
【００１８】上記残厚ｔ3 に対し残厚ｔ2 はそれよりも
やや厚く、上記防爆圧＋αの圧力で切裂する厚さであ
り、実際には例えば５０〜８０μｍと設定される。残厚
ｔ1 は、残厚ｔ2 に封口板１ａの板素材厚さＴの半分又
はそれ以下の厚さを加えたものとして設定され、例えば
Ｔ＝０．４〜０．６ｍ／ｍ、ｔ1 ＝０．２〜０．３ｍ／
ｍである。The remaining thickness t 2 is slightly thicker than the remaining thickness t 3 , and is a thickness that is cut by the above explosion-proof pressure + α, and is actually set to, for example, 50 to 80 μm. Residual thickness t 1 is set as a plus half or less of the thickness of the plate material thickness T of the sealing plate 1a in residual thickness t 2, for example, T = 0.4~0.6m / m, t 1 = 0.2-0.3m /
m.
【００１９】上記第１〜第３加工部分４ａ〜４ｃのそれ
ぞれの残厚ｔ1 〜ｔ3 の設定をまとめて記すと次の通り
である。The settings of the remaining thicknesses t 1 to t 3 of the first to third processed portions 4a to 4c are collectively described as follows.
【００２０】 (1) 第１加工部分４ａの残厚ｔ1 （Ｔ：板素材厚さ） 実際の例 ｔ1 ＝ｔ2 ＋（Ｔ／２〜０） （ｍ／ｍ） （ｔ1 ＝ 0.2〜0.3 ） (2) 第２加工部分４ｂの残厚ｔ2 ｔ2 ＝第３加工部分の防爆圧＋α （ｔ2 ＝0.05〜0.08） 〔ｋｇｆ／ｃｍ2 〕で切裂する厚さ（ｍ／ｍ） 但し、αは０〜１０〔ｋｇｆ／ｃｍ2 〕 (3) 第３加工部分４ｃの残圧ｔ3 、屈曲量Ｄ ｔ3 ＝大気圧以上の適当な防爆設定圧で （ｔ3 ＝0.02〜0.03） 切裂する厚さ（ｍ／ｍ） Ｄ＜２ｔ2 （ｍ／ｍ） （Ｄ＜ 0.1〜 0.16 ） 上記αは、第３加工で屈曲加工して残厚ｔ3 が残るよう
に必然的に防爆圧より少し大きくなる圧力で切裂する残
厚ｔ2 を得るに必要な圧力として設定され、かつ設定さ
れたｔ2 が耐衝撃性に十分な値となるように定められて
いる。又、Ｄについては、過度の屈曲によりクラックが
生じない寸法で、かつ内圧で封口板１ａの中央部分が外
側へ突出しようしとて屈曲断面部がストレート形状に延
びたときに金属疲労が生じる寸法であり、経験的に定め
られる値である。(1) Actual example of the remaining thickness t 1 (T: plate material thickness) of the first processed portion 4a t 1 = t 2 + (T / 2 to 0) (m / m) (t 1 = 0.2 0.3) (2) anti爆圧+ alpha (t 2 = 0.05 to 0.08) [kgf / cm 2] thickness to Setsu裂in of residual thickness t 2 t 2 = third working portion of the second working portion 4b (m / m) where α is 0 to 10 [kgf / cm 2 ] (3) Residual pressure t 3 and bending amount D t 3 of the third processed portion 4c = appropriate explosion-proof set pressure not less than atmospheric pressure (t 3 = 0.02 0.03) Setsu裂thickness of (m / m) D <2t 2 (m / m) (D <0.1~ 0.16) above α is bent machined necessarily to leave the remaining thickness t 3 and the third machining The pressure is set as a pressure necessary to obtain a residual thickness t 2 that is torn at a pressure slightly larger than the explosion-proof pressure, and the set t 2 is determined to be a value sufficient for impact resistance. The dimension D is a dimension that does not cause cracks due to excessive bending, and a dimension that causes metal fatigue when the central section of the sealing plate 1a tries to protrude outward due to the internal pressure and the bent cross section extends in a straight shape. Is an empirically determined value.
【００２１】なお、外装缶１の素材はスチール製、封口
板１ａはアルミニウム又はスチール製である。又、二次
電池の主要構造は特徴ではないため図示省略している
が、例えば陰極としてリチウム金属板、陽性として硫化
モリブデンなどを含む正極活物質、電解液としてリチウ
ムを含む有機溶媒が用いられたリチウム二次電池などが
対象として挙げられる。The material of the outer can 1 is made of steel, and the sealing plate 1a is made of aluminum or steel. In addition, although the main structure of the secondary battery is not shown because it is not a feature, for example, a lithium metal plate as a cathode, a positive electrode active material containing molybdenum sulfide or the like as a positive electrode, and an organic solvent containing lithium as an electrolytic solution were used. Examples include lithium secondary batteries.
【００２２】さらに、封口板１ａは後で説明する第２実
施形態のような絞り加工を施していないから、封口板１
ａの面は大部分外装缶１の端部と同一端面内に設けられ
ているが、封口板１ａの中央部附近のみ電極部３が突出
しないように凹入状に形成されている。Further, since the sealing plate 1a is not subjected to the drawing process as in a second embodiment described later, the sealing plate 1a
The surface a is mostly provided in the same end surface as the end of the outer can 1, but is formed in a concave shape so that the electrode portion 3 does not protrude only near the center of the sealing plate 1a.
【００２３】以上のように形成した安全弁４を含むこの
実施形態の二次電池は、過度の充電が行われて外装缶内
に内圧が生じても、安全弁が従来より低い防爆圧で安全
確実にしかも設定された防爆圧からわずかな誤差範囲内
で作動し、かつ電池を落下させたときなどの衝撃があっ
ても安全弁４が破壊されないものである。The rechargeable battery of this embodiment including the safety valve 4 formed as described above ensures the safety valve with a lower explosion-proof pressure than before, even if the internal pressure is generated in the outer can due to excessive charging. In addition, the safety valve 4 operates within a small error range from the set explosion-proof pressure, and the safety valve 4 is not destroyed even when an impact such as when the battery is dropped.
【００２４】上記安全弁４は、その残厚ｔ1 〜ｔ3 を上
述した寸法とすることを前提として、第２加工部分４ｂ
の切欠溝に第３加工部分４ｃの屈曲断面部を形成するこ
とにより上記のような所要の動作機能を実現している。
実際例として、例えば第３残厚ｔ3 ＝０．０３ｍ／ｍと
したばあいの防爆圧は約５ｋｇｆ／ｃｍ2 ±１ｋｇｆ／
ｃｍ2 であり、従来のものが１５〜４５ｋｇｆ／ｃｍ2
±５ｋｇｆ／ｃｍ2 であるのに比して防爆圧が極めて低
く、誤差範囲も小さいことが分る。The safety valve 4 has a second processing portion 4b provided that the remaining thicknesses t 1 to t 3 have the dimensions described above.
The required operation function as described above is realized by forming the bent cross section of the third processed portion 4c in the notched groove.
As a practical example, for example, when the third remaining thickness t 3 = 0.03 m / m, the explosion-proof pressure is about 5 kgf / cm 2 ± 1 kgf /
cm 2, and those of conventional 15~45kgf / cm 2
It can be seen that the explosion-proof pressure is extremely low and the error range is small as compared with ± 5 kgf / cm 2 .
【００２５】万一外装缶内に内圧が生じると、その内圧
が安全弁４より内径側の面積に作用して外向きに突出さ
せるように働く。このため安全弁４の屈曲断面部は図２
に一点鎖線で示すように変形し山形形状がストレート状
に延びて屈曲断面部は金属疲労及び内圧により破断が生
じる。従って、屈曲断面部の第３残厚は極めて薄いため
容易に破断するのである。If an internal pressure is generated in the outer can, the internal pressure acts on the area on the inner diameter side of the safety valve 4 and acts to project outward. Therefore, the bent cross section of the safety valve 4 is shown in FIG.
As shown by the dashed line in FIG. 2, the mountain shape extends straight, and the bent cross section is broken by metal fatigue and internal pressure. Therefore, since the third remaining thickness of the bent cross section is extremely thin, it is easily broken.
【００２６】しかし、このような内圧が生じない限り、
屈曲断面部は第３残厚ｔ3 が極めて薄いとしても屈曲状
に形成されているため衝撃作用が働らいても破断が生じ
ることはない。屈曲状とすることにより構造強度が大き
く、単に第３残厚ｔ3 の材料をフラットに形成するより
も丈夫だからである。However, unless such an internal pressure occurs,
Even if the third remaining thickness t 3 is extremely thin, the bent cross section is formed in a bent shape, so that even when an impact action is applied, no break occurs. This is because the bent shape increases the structural strength and is stronger than simply forming the material having the third remaining thickness t 3 flat.
【００２７】以上の動作説明から分るように、この実施
形態の安全弁で屈曲部断面部の構造を採用した理由は、
フラットな押圧部の一部に設けた切欠溝のみとするとそ
の残厚ｔ2 が厚過ぎて防爆圧が大きくなり、設定圧で確
実に安定して安全弁として作動するとは限らないからで
ある。上記残厚ｔ2 を薄くすると防爆圧を小さくするこ
とはできるが、電池が使用時に落下したりしたときの衝
撃力で切欠溝が破断する虞れがある。As can be seen from the above description of the operation, the reason why the structure of the bent section is adopted in the safety valve of this embodiment is as follows.
When only notched groove formed in a portion of the flat pressing portion proof爆圧becomes larger the residual thickness t 2 is too thick, because not always operate as a safety valve reliably stable at the set pressure. It is possible to reduce the explosion爆圧Thinning the residual thickness t 2, but there is a possibility that the battery is notched grooves impact force when dropped or at the time of use to break.
【００２８】一方、残厚ｔ2 を破断事故が生じない程と
するとｔ2 が厚過ぎて防爆圧を一定以下に下げることが
できなくなる。従ってこのような２つの互いに相反する
条件をフラットな押圧部の一部に設けた切欠溝のみの安
全弁構造で満足させることはできず、切欠溝部分に屈曲
断面部を形成することにより、上記２つの条件を満足さ
せるようにしたのである。[0028] On the other hand, it will not be able to have enough to and t 2 is too thick that does not cause rupture accident the remaining thickness t 2 lower the anti-爆圧below a certain level. Therefore, such two mutually contradictory conditions cannot be satisfied by the safety valve structure having only the notch groove provided in a part of the flat pressing portion. The two conditions were satisfied.
【００２９】次に、上記安全弁４の形成方法について図
３を参照して簡単に説明する。図３は第１〜第３加工部
分４ａ〜４ｃを形成する過程を示している。図において
（ａ）図では第１加工部分４ａのプレス加工が行なわれ
る。１０はプレス台、１１はプレスパンチである。封口
板１ａの板素材厚さはＴのものを用いてプレスパンチ１
１により第１加工部分４ａの平板状凹部をプレス成形す
る。このとき、第１加工部分４ａに基礎残厚として残厚
ｔ1 が残るように成形する。Next, a method of forming the safety valve 4 will be briefly described with reference to FIG. FIG. 3 shows a process of forming the first to third processed portions 4a to 4c. In the figure, in the figure (a), the first working part 4a is pressed. Reference numeral 10 denotes a press table, and 11 denotes a press punch. The thickness of the sealing plate 1a is T, and the pressing punch 1 is used.
According to 1, the flat recess of the first processed portion 4a is press-formed. At this time, residual thickness t 1 is shaped so as to be left as a basis the residual thickness on the first working portion 4a.
【００３０】（ｂ）図では第２加工部分４ｂのプレス加
工を行なう。このプレス加工では第１加工部分４ａの平
板状凹部の一部に第２加工部分４ｂのフラットな押圧部
とその一部に設けられる切欠溝の形状に対応する突起部
を備えたプレスパンチ１１’を用いて第２加工部分４ｂ
に残る残厚がｔ2 となるようにプレスされる。In FIG. 2B, the second working portion 4b is pressed. In this press working, a press punch 11 ′ having a flat pressing part of the second processing part 4 b and a projection corresponding to the shape of a notch groove provided in a part of the flat recess of the first processing part 4 a is provided. Using the second processing portion 4b
Is pressed so that the remaining thickness remaining at time t 2 becomes t 2 .
【００３１】（ｃ）図では第３加工部分４ｃのプレス加
工を行なう。このプレス加工では第２加工部分４ｂの切
欠溝部分に第３加工部分４ｃの屈曲断面部に対応する突
起部を備えたプレスパンチ１５を用いて第３加工部分４
ｃの屈曲部残厚が図２に示すｔ3 となるようにプレスさ
せる。但し、このプレス加工ではプレスパンチ１５は切
欠溝面とは反対側に置かれ、プレス台１４がプレスパン
チ１５に対向するように置かれる。（ｄ）図は第３加工
部分４ｃの部分拡大図を示す。In FIG. 3C, the third working portion 4c is pressed. In this press working, the third working portion 4 is formed by using a press punch 15 having a projection corresponding to the bent cross section of the third working portion 4c in the notch groove portion of the second working portion 4b.
Pressing is performed so that the remaining thickness of the bent portion c becomes t 3 shown in FIG. However, in this press working, the press punch 15 is placed on the side opposite to the notched groove surface, and the press table 14 is placed so as to face the press punch 15. (D) is a partially enlarged view of the third processed portion 4c.
【００３２】以上の加工処理方法によって図１、図２に
示す断面形状の封口板１ａが得られ、上記実施形態では
封口板１ａの外面側に第１加工部分４ａの平板状凹部、
第２加工部分４ｂの切欠溝を設け、反対側の内面側から
突き上げるプレス加工で第３加工部分４ｃの屈曲断面部
を形成したが、第１加工部分４ａ、第２加工部分４ｂは
必らずしも外面側でなくても内面側に設けてもよく、第
３加工部分４ｃは外面側へ突出するように形成したもの
とすることもできる。The sealing plate 1a having the cross-sectional shape shown in FIGS. 1 and 2 is obtained by the above processing method. In the above embodiment, the flat plate-shaped recess of the first processing portion 4a is formed on the outer surface side of the sealing plate 1a.
The notched groove of the second processed portion 4b was provided, and the bent cross-section of the third processed portion 4c was formed by pressing up from the inner surface on the opposite side, but the first processed portion 4a and the second processed portion 4b are not necessarily required. The third processed portion 4c may be formed so as to protrude toward the outer surface side, instead of being provided on the inner surface side instead of the outer surface side.
【００３３】図４に絞り加工部分４ｄを施した封口板１
ａを備えた二次電池の断面図を示す。この実施形態では
封口板１ａは絞り加工によりその外周縁が外装缶１の端
部から所定深さに凹入状に形成され、中央の電極部３が
端部から突出しないように形成されている。このような
封口板１ａに設けられた安全弁４は、図５に示すよう
に、図３の（ａ）〜（ｃ）図の第１〜３加工部分４ａ〜
４ｃを形成する加工処理方法に（ｋ）図の絞り加工部分
４ｄを形成する加工処理方法を付加した方法で形成され
る。FIG. 4 shows a sealing plate 1 having a drawn portion 4d.
1 shows a cross-sectional view of a secondary battery provided with a. In this embodiment, the outer peripheral edge of the sealing plate 1a is formed into a concave shape at a predetermined depth from the end of the outer can 1 by drawing, and the central electrode portion 3 is formed so as not to protrude from the end. . As shown in FIG. 5, the safety valve 4 provided on such a sealing plate 1a has first to third processing portions 4a to 4c shown in FIGS.
It is formed by a method obtained by adding a processing method for forming the drawn portion 4d in the drawing (k) to the processing method for forming 4c.
【００３４】この実施形態の封口板１ａを形成する場
合、（ａ）図の第１加工部分４ａの形成が必須であり省
略してはならない。その理由は、（ｋ）図での絞り加工
部分４ｄの形成の後に行われる第２加工処理で行うとす
ると、そのプレス加工による素材肉部の移動が大きくな
り絞り加工部分４ｄに対し材料硬化などの大きな影響を
与え、又加工変形により封口板１ａが不完全なものとな
るからである。In the case of forming the sealing plate 1a of this embodiment, the formation of the first processed portion 4a in FIG. The reason is that if it is performed in the second processing performed after the formation of the drawn portion 4d in the drawing (k), the movement of the raw material portion due to the press work becomes large, and the material hardening or the like is performed on the drawn portion 4d. This is because the sealing plate 1a becomes incomplete due to processing deformation.
【００３５】なお、第１加工部分４ａを省略して第２加
工部分４ｂを１段の加工処理で行なう場合の影響は、絞
り加工部分４ｄを設けない場合でも封口板１ａの材料硬
化、加工変形を無視できないものとして発生する。従っ
て、絞り加工を加えない第１実施形態の安全弁４を形成
する場合でも同様に第１加工部分４ａを施すのが望まし
いが、材質、素材板厚によって上記の影響が小さければ
第１加工部分４ａを省略してもよい。The effect of omitting the first processed portion 4a and performing the second processed portion 4b by one-stage processing is affected by the hardening of the material of the sealing plate 1a and the processing deformation even when the drawn portion 4d is not provided. Occurs as something that cannot be ignored. Therefore, it is desirable to similarly apply the first processed portion 4a even when forming the safety valve 4 of the first embodiment without drawing, but if the above-described influence is small depending on the material and the material plate thickness, the first processed portion 4a May be omitted.
【００３６】[0036]
【発明の効果】以上、詳細に説明したように、この発明
の二次電池防爆構造は外装缶端の封口板に安全弁を設
け、この安全弁を基礎残厚を残して形成した平板状凹部
に第２残厚が残るように切欠溝を形成し、この切欠溝に
屈曲断面部を形成してその第３残厚が大気圧より大きい
防爆圧以上の内圧で切裂する残厚となるものとして形成
したから、従来よりはるかに低い防爆圧で安全、確実に
しかも設定された防爆圧からわずかな誤差範囲内で作動
し、かつ落下による衝撃作用で破断することがないなど
極めて優れた効果が得られる。As described in detail above, the secondary battery explosion-proof structure of the present invention is provided with a safety valve on the sealing plate at the end of the outer can, and the safety valve is formed in a flat recess formed with a basic remaining thickness. (2) A notch groove is formed so that the remaining thickness remains, and a bent cross-section is formed in the notch groove, and the third remaining thickness is formed as a remaining thickness that is torn at an internal pressure equal to or greater than the atmospheric pressure and equal to or greater than the explosion-proof pressure. As a result, extremely excellent effects are obtained, such as operating safely and reliably at a much lower explosion-proof pressure than before, operating within a small error range from the set explosion-proof pressure, and not breaking due to the impact action due to dropping .
【図１】第１実施形態の二次電池の縦断面図FIG. 1 is a longitudinal sectional view of a secondary battery according to a first embodiment.
【図２】同上の安全弁部分の拡大断面図FIG. 2 is an enlarged sectional view of a safety valve part according to the first embodiment;
【図３】安全弁の形成方法の説明図FIG. 3 is an explanatory view of a method for forming a safety valve.
【図４】第２実施形態の二次電池の縦断面図FIG. 4 is a longitudinal sectional view of a secondary battery according to a second embodiment.
【図５】同上の安全弁の形成方法の説明図FIG. 5 is an explanatory diagram of a method for forming the safety valve according to the first embodiment.
１ 外装缶 １ａ 封口板 ２ 発電要素 ３ 電極部 ４ 安全弁 ４ａ 第１加工部分 ４ｂ 第２加工部分 ４ｃ 第３加工部分 ４ｄ 絞り加工部分 DESCRIPTION OF SYMBOLS 1 Outer can 1a Sealing plate 2 Power generation element 3 Electrode part 4 Safety valve 4a 1st processed part 4b 2nd processed part 4c 3rd processed part 4d Drawing part
Claims (3)
の封口板又は底板に内圧で変形する切欠き溝を有する安
全弁を設けた二次電池において、上記安全弁部位の板素
材に基礎残厚が残るように平板状凹部を形成し、この凹
部に基礎残厚から板素材厚の半分又はそれ以下の厚さを
滅じた厚さで、かつ防爆圧に所定の圧力を加えた圧力で
切裂する第２残厚が残るように切欠溝を形成し、上記切
欠溝に溝面が屈曲した屈曲断面部を形成してその第３残
厚が大気圧より大きい防爆圧以上の内圧で切裂する残厚
となるようにしたことを特徴とする二次電池の防爆構
造。1. A secondary battery in which a safety valve having a cutout groove deformable by internal pressure is provided in a sealing plate or a bottom plate at an upper end portion of a battery outer can housing a power generating element. Is formed in such a way that the thickness of the base material thickness is reduced to half or less of the thickness of the base material from the basic residual thickness, and cut off at a pressure obtained by applying a predetermined pressure to the explosion-proof pressure. A notch groove is formed so as to leave a second remaining thickness to be cracked, and a bent cross-section in which a groove surface is bent is formed in the notch groove, and the third remaining thickness is greater than the atmospheric pressure. The explosion-proof structure of a secondary battery, characterized in that the remaining thickness of the battery is reduced.
突出するように形成したことを特徴とする請求項１に記
載の二次電池の防爆構造。2. The explosion-proof structure for a secondary battery according to claim 1, wherein the bent cross section is formed such that a groove bending surface protrudes toward a notch groove.
させ封口板内周面を外周縁部より凹入状に形成したこと
を特徴とする請求項１又は２に記載の二次電池の防爆構
造。3. The secondary battery according to claim 1, wherein the outer peripheral edge of the sealing plate is projected by drawing, and the inner peripheral surface of the sealing plate is formed to be recessed from the outer peripheral edge. Explosion-proof structure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11196137A JP2001023596A (en) | 1999-07-09 | 1999-07-09 | Explosion-proof construction of secondary battery |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11196137A JP2001023596A (en) | 1999-07-09 | 1999-07-09 | Explosion-proof construction of secondary battery |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2001023596A true JP2001023596A (en) | 2001-01-26 |
Family
ID=16352858
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11196137A Pending JP2001023596A (en) | 1999-07-09 | 1999-07-09 | Explosion-proof construction of secondary battery |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2001023596A (en) |
Cited By (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100440937B1 (en) * | 2002-02-06 | 2004-07-21 | 삼성에스디아이 주식회사 | Cap assembly with safety valve and rectangular- type secondary battery therewith |
| JP2005235531A (en) * | 2004-02-18 | 2005-09-02 | Hitachi Maxell Ltd | Sealed battery |
| JP2006147267A (en) * | 2004-11-18 | 2006-06-08 | Hitachi Maxell Ltd | Sealing square battery |
| JP2006236949A (en) * | 2005-02-28 | 2006-09-07 | Kaga Inc | Safety valve plate of sealed battery case, its molding method and its molding device |
| JP2008159313A (en) * | 2006-12-21 | 2008-07-10 | Xerom:Kk | Safety valve structure for secondary battery, and manufacturing method therefor |
| CN100433408C (en) * | 2003-09-30 | 2008-11-12 | 日立麦克赛尔株式会社 | Sealed rectangular battery |
| JP2009004271A (en) * | 2007-06-22 | 2009-01-08 | Kobe Steel Ltd | Battery case |
| CN102130313A (en) * | 2010-01-12 | 2011-07-20 | 比克国际(天津)有限公司 | Soft packaging battery and battery pack |
| JP2011175937A (en) * | 2010-02-25 | 2011-09-08 | Sanyo Electric Co Ltd | Sealed battery |
| JP2014209490A (en) * | 2010-10-13 | 2014-11-06 | 株式会社ソーデナガノ | Method of manufacturing lid for battery case and lid for battery case |
| CN105938888A (en) * | 2016-06-20 | 2016-09-14 | 深圳天珑无线科技有限公司 | Method for setting explosion-proof line of battery and explosion-proof battery |
-
1999
- 1999-07-09 JP JP11196137A patent/JP2001023596A/en active Pending
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100440937B1 (en) * | 2002-02-06 | 2004-07-21 | 삼성에스디아이 주식회사 | Cap assembly with safety valve and rectangular- type secondary battery therewith |
| CN100433408C (en) * | 2003-09-30 | 2008-11-12 | 日立麦克赛尔株式会社 | Sealed rectangular battery |
| JP2005235531A (en) * | 2004-02-18 | 2005-09-02 | Hitachi Maxell Ltd | Sealed battery |
| JP2006147267A (en) * | 2004-11-18 | 2006-06-08 | Hitachi Maxell Ltd | Sealing square battery |
| JP4692985B2 (en) * | 2004-11-18 | 2011-06-01 | 日立マクセル株式会社 | Sealed prismatic battery |
| JP2006236949A (en) * | 2005-02-28 | 2006-09-07 | Kaga Inc | Safety valve plate of sealed battery case, its molding method and its molding device |
| JP2008159313A (en) * | 2006-12-21 | 2008-07-10 | Xerom:Kk | Safety valve structure for secondary battery, and manufacturing method therefor |
| JP2009004271A (en) * | 2007-06-22 | 2009-01-08 | Kobe Steel Ltd | Battery case |
| CN102130313A (en) * | 2010-01-12 | 2011-07-20 | 比克国际(天津)有限公司 | Soft packaging battery and battery pack |
| JP2011175937A (en) * | 2010-02-25 | 2011-09-08 | Sanyo Electric Co Ltd | Sealed battery |
| JP2014209490A (en) * | 2010-10-13 | 2014-11-06 | 株式会社ソーデナガノ | Method of manufacturing lid for battery case and lid for battery case |
| CN105938888A (en) * | 2016-06-20 | 2016-09-14 | 深圳天珑无线科技有限公司 | Method for setting explosion-proof line of battery and explosion-proof battery |
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