JP5692048B2

JP5692048B2 - Sealed battery

Info

Publication number: JP5692048B2
Application number: JP2011283875A
Authority: JP
Inventors: 俊樹原
Original assignee: Toyota Motor Corp
Current assignee: Toyota Motor Corp
Priority date: 2011-12-26
Filing date: 2011-12-26
Publication date: 2015-04-01
Anticipated expiration: 2031-12-26
Also published as: JP2013134869A

Description

本発明は、密閉型電池に関し、より詳細には、樹脂からなる絶縁部材を備えた密閉型電池に関する。 The present invention relates to a sealed battery, and more particularly, to a sealed battery provided with an insulating member made of resin.

従来、密閉型電池として、電池ケースの蓋体と電極端子とを樹脂からなる絶縁部材を介して一体化するとともに、蓋体と電池ケースとの溶接部（接合部）が電池ケース側面に設けられた構成は公知となっている（例えば、特許文献１）。具体的には、特許文献１には、箱形（すなわち有底四角筒状）のケース本体の開口部に、蓋体を装着して、蓋体とケース本体との合わせ目をレーザ溶接により封止される旨の記載がある。 Conventionally, as a sealed battery, a battery case lid and electrode terminals are integrated via an insulating member made of resin, and a welded portion (joint) between the lid and the battery case is provided on the side of the battery case. Such a configuration is known (for example, Patent Document 1). Specifically, Patent Document 1 discloses that a lid is attached to an opening of a box-shaped (that is, bottomed rectangular tube) case body, and a joint between the lid body and the case body is sealed by laser welding. There is a statement that it will be stopped.

また、特許文献１には、絶縁部材の構成材料として、使用する電解液に対して耐性を示す各種の絶縁性ポリマー材料（いわゆる、樹脂材料）を適宜選択して用いることができる旨の記載がある。 Patent Document 1 also describes that various insulating polymer materials (so-called resin materials) that are resistant to the electrolytic solution used can be appropriately selected and used as the constituent material of the insulating member. is there.

特開２０１０−２８２８４７号公報JP 2010-282847 A

特許文献１のように、蓋体とケース本体との合わせ目をレーザ溶接して電池ケースを形成する場合、その生産性を考慮すると、溶接部を蓋体上面側（図９（ａ）（ｂ）の太線部分）へ設けることが考えられる。しかし、溶接部の位置を従来の電池ケース側面から蓋体上面側に変更した場合、蓋体上方から電池ケースの縦方向にレーザを照射して溶接することになり（図９（ｂ）の点線矢印参照）、従来よりも溶接部が絶縁部材（樹脂部材）に近接するため当該絶縁部材が溶接時にビーム散乱光を吸収してしまい熱害を受けてしまう。 When the battery case is formed by laser welding the joint between the lid and the case body as in Patent Document 1, considering the productivity, the welded portion is placed on the lid upper surface side (FIGS. 9A and 9B). It is conceivable that it is provided at the thick line part). However, when the position of the welded portion is changed from the side surface of the conventional battery case to the upper surface side of the lid body, the welding is performed by irradiating a laser in the vertical direction of the battery case from above the lid body (dotted line in FIG. 9B). Since the welded part is closer to the insulating member (resin member) than in the past, the insulating member absorbs the beam scattered light at the time of welding and suffers heat damage.

例えば、角型密閉型電池の場合、従来は溶接部と絶縁部材（樹脂部材）とは所定の間隔を保つことでレーザ溶接の吸収・入熱等による劣化を防ぐことが可能であったが、電池の小型化が進むことにより、図９（ｂ）に示すように、絶縁部材と、ケース本体と蓋体との溶接部位が近づくことで、溶接時に絶縁部材が熱劣化することが考えられる。 For example, in the case of a rectangular sealed battery, it has been possible to prevent deterioration due to absorption and heat input of laser welding by maintaining a predetermined distance between the welded portion and the insulating member (resin member). As shown in FIG. 9B, it is conceivable that the insulation member is thermally deteriorated during welding by approaching the welded portion between the insulation member, the case main body, and the lid body as the size of the battery advances.

一方、電極端子と電池ケース（蓋体）の絶縁を保つ絶縁部材としては、絶縁性及びシール性において樹脂製が好ましく、レーザ溶接時の熱の影響が少なく、かつシール性を確保したものが望まれる。 On the other hand, as an insulating member for maintaining insulation between the electrode terminal and the battery case (lid), a resin is preferable in terms of insulation and sealing properties, and it is desirable to have a little influence of heat during laser welding and ensure sealing properties. It is.

そこで、本発明は、レーザ溶接時の熱による悪影響を防ぎ、かつシール性を十分に確保した樹脂からなる絶縁部材を備える密閉型電池を提供することを目的とする。 Therefore, an object of the present invention is to provide a sealed battery including an insulating member made of a resin that prevents adverse effects due to heat at the time of laser welding and sufficiently secures sealing performance.

本発明の解決しようとする課題は以上の如くであり、次にこの課題を解決するための手段を説明する。 The problem to be solved by the present invention is as described above. Next, means for solving the problem will be described.

即ち、請求項１においては、
蓋体とケース本体からなる電池ケースと電極端子とを樹脂からなる絶縁部材を介して一体化するとともに、前記蓋体と前記ケース本体とをレーザ溶接して形成される密閉型電池において、
前記絶縁部材は、
前記電極端子を挿通するための挿通孔と、
前記挿通孔周囲に形成される母材と、
前記母材を除く部分と、からなり、
前記母材を除く部分を非芳香族化合物であるＰＯＭまたはＰＡ６６により形成するとともに、前記母材を前記非芳香族化合物よりもへたり特性が高い樹脂材料であるＰＰＳまたはＰＥＥＫにて形成したものである。 That is, in claim 1,
In a sealed battery formed by integrating a battery case and electrode terminals made of a lid and a case body via an insulating member made of resin, and laser welding the lid and the case body,
The insulating member is
An insertion hole for inserting the electrode terminal;
A base material formed around the insertion hole;
A portion excluding the base material,
The portion excluding the base material is formed of POM or PA66 which is a non-aromatic compound, and the base material is formed of PPS or PEEK which is a resin material having higher characteristics than the non-aromatic compound. is there.

請求項２においては、
前記母材と前記母材を除く部分とは、二色成形により一体に形成されるものである。 In claim 2 ,
The base material and the portion excluding the base material are integrally formed by two-color molding.

本発明によれば、レーザ溶接時のレーザによる熱害の防止とシール性の確保を両立することができる。 ADVANTAGE OF THE INVENTION According to this invention, prevention of the heat damage by the laser at the time of laser welding and ensuring of sealing performance can be made compatible.

（ａ）は本発明の一実施形態に係る密閉型電池を示す斜視図、（ｂ）は（ａ）の一部を拡大して示す斜視図。(A) is a perspective view which shows the sealed battery which concerns on one Embodiment of this invention, (b) is a perspective view which expands and shows a part of (a). 図１におけるＡ−Ａ'矢視断面図。AA 'arrow sectional drawing in FIG. 外部絶縁部材を示す平面図。The top view which shows an external insulation member. Ｈｅ（ヘリウム）リークディテクターによるシール性評価を説明するための説明図。Explanatory drawing for demonstrating the sealing performance evaluation by a He (helium) leak detector. レーザ溶接時の外部絶縁部材の熱劣化評価を説明するための説明図。Explanatory drawing for demonstrating the thermal deterioration evaluation of the external insulation member at the time of laser welding. （ａ）は外部絶縁部材のバスバ締結時における界面剥離評価を説明する説明図、（ｂ）は単位長により外部絶縁部材７の各部位の長さを説明する説明図。(A) is explanatory drawing explaining the interface peeling evaluation at the time of the bus bar fastening of an external insulating member, (b) is explanatory drawing explaining the length of each site | part of the external insulating member 7 by unit length. 図６（ａ）におけるＢ−Ｂ'矢視断面図。BB 'arrow sectional drawing in Fig.6 (a). 外部絶縁部材の別実施形態を示す図であり、（ａ）はギア歯を備えた母材を有する外部絶縁部材を示す平面図、（ｂ）は平面視四角形状の母材を有する外部絶縁部材を示す図。It is a figure which shows another embodiment of an external insulation member, (a) is a top view which shows the external insulation member which has a preform | base_material provided with the gear teeth, (b) is an external insulation member which has a square-shaped base material in planar view FIG. （ａ）は密閉型電池の溶接部と絶縁部材との位置関係を示す斜視図、（ｂ）は（ａ）の一部を拡大して示す斜視図。(A) is a perspective view which shows the positional relationship of the welding part and insulation member of a sealed battery, (b) is a perspective view which expands and shows a part of (a).

次に、発明の実施の形態を説明する。
先ず、本発明に係る密閉型電池の一実施形態である電池１０の構成について図１及び図２を用いて説明する。本実施形態では、捲回型の電極体（捲回電極体）と非水電解液とを扁平な角型のケースに収容して、充放電可能に構成される密閉型リチウムイオン二次電池を例として挙げる。
なお、以下では、同じ作用を奏する部材については同じ符号を付して、その説明を省略する場合がある。 Next, embodiments of the invention will be described.
First, the structure of the battery 10 which is one embodiment of the sealed battery according to the present invention will be described with reference to FIGS. 1 and 2. In the present embodiment, a sealed lithium ion secondary battery configured to be chargeable / dischargeable by accommodating a wound electrode body (wound electrode body) and a nonaqueous electrolytic solution in a flat rectangular case. Take as an example.
In the following description, members having the same action are denoted by the same reference numerals and description thereof may be omitted.

電池１０は、蓋体２ｂとケース本体２ａからなる電池ケース２と電極端子３とを樹脂からなる絶縁部材４を介して一体化するとともに、蓋体２ｂとケース本体２ａとを溶接して形成される角型のリチウムイオン二次電池であって、図１及び図２に示すように、充放電要素１（図２参照）と、充放電要素１を内部に収容する電池ケース２と、電極端子３と、絶縁部材４と、を備える。 The battery 10 is formed by integrating a battery case 2 composed of a lid 2b and a case body 2a and an electrode terminal 3 via an insulating member 4 made of resin, and welding the lid 2b and the case body 2a. 1 and 2, a charge / discharge element 1 (see FIG. 2), a battery case 2 that houses the charge / discharge element 1 therein, and an electrode terminal 3 and an insulating member 4.

充放電要素１は、正極と負極とをセパレータを介して積層し、複数回巻回されてなる電極体である。正極及び負極の積層部分には、それぞれ正極活物質又は負極活物質を含む合材が担持されている。充放電要素１は、積層部分における正極・負極間の化学反応により充放電が行われる。 The charge / discharge element 1 is an electrode body formed by laminating a positive electrode and a negative electrode via a separator and wound a plurality of times. The laminated part of the positive electrode and the negative electrode carries a positive electrode active material or a mixture containing a negative electrode active material, respectively. The charge / discharge element 1 is charged / discharged by a chemical reaction between the positive electrode and the negative electrode in the laminated portion.

電池ケース２は、充放電要素１及び電解液（図示せず）を内部に収容する直方体形状の金属製の部材である。電池ケース２は、ケース本体２ａ及び蓋体２ｂ等により角型の電池容器として形成される。 The battery case 2 is a rectangular parallelepiped metal member that houses the charging / discharging element 1 and an electrolytic solution (not shown) therein. The battery case 2 is formed as a rectangular battery container by the case body 2a, the lid body 2b, and the like.

ケース本体２ａは、一面（図２では、上面）が開口された有底の角筒状の部材であり、内部に充放電要素１及び電解液が収容される。 The case main body 2a is a bottomed rectangular tube-shaped member whose one surface (the upper surface in FIG. 2) is opened, and the charge / discharge element 1 and the electrolytic solution are accommodated therein.

蓋体２ｂは、ケース本体２ａの開口部内側に応じた形状（本実施形態では、平面視略矩形状）を有する平板状部材であり、ケース本体２ａの開口部を閉塞するための部材である。蓋体２ｂには、蓋体２ｂの両側部に設けられた後述する集電端子３ａ・３ａのリベット部６を挿通するためのリベット挿通孔２ｃ・２ｃが形成されている。リベット挿通孔２ｃ・２ｃは、蓋体２ｂの厚さ方向に蓋体２ｂを貫通する貫通孔であり、所定の内径を有する。蓋体２ｂには、リベット挿通孔２ｃ・２ｃの間（本実施態様では、蓋体２ｂの長手方向の略中央）に、電池ケース２の内圧が上昇した場合に当該電池ケース２の内外を連通させて内圧を開放するための安全弁２ｄが設けられている。蓋体２ｂは、ケース本体２ａの開口部を閉塞した状態（図２の点線丸印で示すように、蓋体２ｂがケース本体２ａ内に嵌合した状態）で、レーザ溶接によりケース本体２ａと接合され、蓋体２ｂとケース本体２ａとの境界部分に当該境界部分が溶融凝固した溶接部（図示せず）が形成される。このレーザ溶接の際には、図２に示す点線矢印方向に向けてレーザ光が照射され、蓋体２ｂとケース本体２ａとの境界部が溶接される（電池ケース２の縦方向にレーザ光が照射されるので「縦打ち溶接」ともいう）。当該縦打ち溶接により、蓋体２ｂとケース本体２ａとが接合され、蓋体２ｂとケース本体２ａとが一体化される。蓋体２ｂ及びケース本体２ａの材料としては、例えばアルミニウムやアルミニウム合金等が挙げられる。 The lid 2b is a flat plate-like member having a shape corresponding to the inside of the opening of the case body 2a (in the present embodiment, a substantially rectangular shape in plan view), and is a member for closing the opening of the case body 2a. . The lid 2b is formed with rivet insertion holes 2c and 2c for inserting rivets 6 of current collecting terminals 3a and 3a described later provided on both sides of the lid 2b. The rivet insertion holes 2c and 2c are through holes that penetrate the lid 2b in the thickness direction of the lid 2b, and have a predetermined inner diameter. When the internal pressure of the battery case 2 rises between the rivet insertion holes 2c and 2c (substantially the center in the longitudinal direction of the lid 2b in this embodiment), the lid 2b communicates with the inside and outside of the battery case 2 A safety valve 2d for releasing the internal pressure is provided. The lid 2b is in a state in which the opening of the case main body 2a is closed (as shown by a dotted circle in FIG. 2), the lid 2b is fitted in the case main body 2a, and is welded to the case main body 2a by laser welding. A welded portion (not shown) is formed at the boundary between the lid 2b and the case main body 2a by melting and solidifying the boundary. During this laser welding, laser light is irradiated in the direction of the dotted arrow shown in FIG. 2, and the boundary between the lid 2b and the case main body 2a is welded (the laser light is irradiated in the vertical direction of the battery case 2). It is also called “vertical welding” because it is irradiated. By the vertical welding, the lid body 2b and the case body 2a are joined, and the lid body 2b and the case body 2a are integrated. Examples of the material of the lid 2b and the case main body 2a include aluminum and aluminum alloys.

電極端子３・３は、一方（図１（ａ）において手前側）が正極端子であり、他方（図１（ａ）において奥側）が負極端子である。電極端子３・３は、それぞれ集電端子３ａ、外部端子部材３ｂ、及びバスバ締結部材３ｃ（図１参照）の３つの部材からなり、当該３つの部材を接続することにより電極端子３・３が構成される。集電端子３ａ、外部端子部材３ｂ、及びバスバ締結部材３ｃは、それぞれ通電可能な金属から形成されている。電極端子３・３の各々は、集電端子３ａ・３ａの各々を介して電池ケース２の内部において充放電要素１の正極及び負極に電気的に接続される。電極端子３・３は、電池１０の外部との充放電のための接続経路となる端子である。電極端子３・３は、後述する３種の絶縁部材である外部絶縁部材７、環状ガスケット８、及び内部絶縁部材９を介して蓋体２ｂに固定される。 One of the electrode terminals 3 and 3 (the front side in FIG. 1A) is a positive electrode terminal, and the other (the back side in FIG. 1A) is a negative electrode terminal. Each of the electrode terminals 3 and 3 includes three members, that is, a current collecting terminal 3a, an external terminal member 3b, and a bus bar fastening member 3c (see FIG. 1), and the electrode terminals 3 and 3 are connected by connecting the three members. Composed. The current collecting terminal 3a, the external terminal member 3b, and the bus bar fastening member 3c are each formed of a metal that can be energized. Each of the electrode terminals 3 and 3 is electrically connected to the positive electrode and the negative electrode of the charge / discharge element 1 inside the battery case 2 via the current collecting terminals 3a and 3a. The electrode terminals 3 and 3 are terminals serving as connection paths for charging and discharging with the outside of the battery 10. The electrode terminals 3 and 3 are fixed to the lid 2b via an external insulating member 7, an annular gasket 8, and an internal insulating member 9 which are three kinds of insulating members described later.

集電端子３ａ・３ａは、屈曲加工された板状の金属製端子部材であり、屈曲した板状の端子本体部５と、当該端子本体部５の一端面上に突出形成された円柱状のリベット部６とを有する。集電端子３ａ・３ａは、端子本体部５の一端が充放電要素１に接続されるともに、リベット部６が電池ケース２の内部からリベット挿通孔２ｃを挿通して蓋体２ｂ上に突出される。リベット部６は、蓋体２ｂ上に突出した状態で、当該リベット部６の頭部をかしめることで、図２に示すようなリベットかしめ部６ａを形成して、蓋体２ｂに固定される。すなわち、リベットかしめ部６ａは、リベット部６の頭部がかしめられ拡径されてフランジ状になり、後述する外部端子部材３ｂのシールかしめ部１２に係合する。 The current collecting terminals 3 a and 3 a are bent plate-like metal terminal members, and are bent plate-like terminal main body portions 5 and columnar shapes protruding on one end surfaces of the terminal main body portions 5. And a rivet portion 6. In the current collecting terminals 3a and 3a, one end of the terminal main body 5 is connected to the charge / discharge element 1, and the rivet portion 6 is inserted from the inside of the battery case 2 through the rivet insertion hole 2c and protrudes onto the lid 2b. The The rivet part 6 is fixed to the lid 2b by forming the rivet caulking part 6a as shown in FIG. 2 by caulking the head of the rivet part 6 in a state of protruding on the lid 2b. . That is, the rivet caulking portion 6a is caulked at the head of the rivet portion 6 to have a flange shape, and is engaged with a seal caulking portion 12 of the external terminal member 3b described later.

外部端子部材３ｂは、側面視略Ｚ字状に屈曲した金属製端子部材（Ｚ端子とも呼ばれる）であり、外部端子部材３ｂの長手方向一端部にバスバ締結部１１と、外部端子部材３ｂの長手方向他端部にシールかしめ部１２と、を有する。バスバ締結部１１には、バスバ締結部材３ｃのネジ部１３を挿通するためのネジ挿通孔１１ａが開口形成されている。また、シールかしめ部１２には、集電端子３ａのリベット部６を挿通するためのリベット挿通孔１２ａが開口形成されている。シールかしめ部１２は、後述する外部絶縁部材７のかしめ部嵌合部７ｂに嵌合可能である。外部端子部材３ｂは、シールかしめ部１２をかしめ部嵌合部７ｂに嵌合し、リベット挿通孔１２ａに集電端子３ａのリベット部６を挿通し、かつネジ挿通孔１１ａにバスバ締結部材３ｃのネジ部１３を挿通した状態で、リベット部６の頭部をかしめることでリベットかしめ部６ａを形成し、外部絶縁部材７を介して蓋体２ｂに固定される。当該固定後、リベットかしめ部６ａは、外部端子部材３ｂのシールかしめ部１２表面に溶接される。このように、リベット部６をリベット挿通孔１２ａに差込み、かしめた後、外部端子部材３ｂと溶接することで、環状ガスケット８を所定の圧縮率で圧縮して、蓋体２ｂの端子挿通孔２ｃをシールすることができる。こうして、外部端子部材３ｂは、外部絶縁部材７を介して蓋体２ｂ上に配置される。 The external terminal member 3b is a metal terminal member (also referred to as a Z terminal) bent in a substantially Z shape when viewed from the side, and includes a bus bar fastening portion 11 at one longitudinal end of the external terminal member 3b and the longitudinal length of the external terminal member 3b. A seal caulking portion 12 is provided at the other end in the direction. The bus bar fastening portion 11 is formed with a screw insertion hole 11a for inserting the screw portion 13 of the bus bar fastening member 3c. The seal caulking portion 12 is formed with a rivet insertion hole 12a for inserting the rivet portion 6 of the current collecting terminal 3a. The seal caulking portion 12 can be fitted to a caulking portion fitting portion 7b of the external insulating member 7 described later. In the external terminal member 3b, the seal caulking portion 12 is fitted into the caulking portion fitting portion 7b, the rivet portion 6 of the current collecting terminal 3a is inserted into the rivet insertion hole 12a, and the bus bar fastening member 3c is inserted into the screw insertion hole 11a. The rivet caulking portion 6a is formed by caulking the head of the rivet portion 6 while the screw portion 13 is inserted, and the rivet caulking portion 6a is fixed to the lid 2b via the external insulating member 7. After the fixing, the rivet caulking portion 6a is welded to the surface of the seal caulking portion 12 of the external terminal member 3b. Thus, after the rivet portion 6 is inserted into the rivet insertion hole 12a and crimped, the annular gasket 8 is compressed at a predetermined compression rate by welding with the external terminal member 3b, and the terminal insertion hole 2c of the lid 2b. Can be sealed. Thus, the external terminal member 3b is disposed on the lid 2b via the external insulating member 7.

バスバ締結部材３ｃは、バスバ（板状の接続具）を締結するための部材であり、外周に雄ネジが形成されたネジ部１３と、当該ネジ部１３を支持する平面視矩形状の基部１４（図７参照）から構成される。ネジ部１３は、前記ネジ挿通孔１１ａに挿通されるとともに、外部端子部材３ｂに電気的に接続される。基部１４は、後述する外部絶縁部材７の基部嵌合部７ａに嵌合される。バスバ締結部材３ｃは、複数の電池１０を接続して組電池を構成する際に、隣接する電池間において一方の正極端子と他方の負極端子とを電気的に接続するためのバスバが締結される締結部位となる。 The bus bar fastening member 3c is a member for fastening a bus bar (plate-shaped connector), and includes a screw portion 13 having a male screw formed on the outer periphery and a rectangular base portion 14 that supports the screw portion 13 in a plan view. (See FIG. 7). The screw portion 13 is inserted into the screw insertion hole 11a and is electrically connected to the external terminal member 3b. The base portion 14 is fitted into a base fitting portion 7a of the external insulating member 7 described later. The bus bar fastening member 3c fastens a bus bar for electrically connecting one positive terminal and the other negative terminal between adjacent batteries when a plurality of batteries 10 are connected to form an assembled battery. It becomes a fastening part.

絶縁部材４は、電極端子３・３と電池ケース２との間を絶縁するための樹脂からなる部材であり、３種類の異なる形状の絶縁部材として、外部絶縁部材７（インシュレータとも呼ばれる）、環状ガスケット８及び内部絶縁部材９からなる。絶縁部材４は、電極端子３・３の各々と電池ケース２（蓋体２ｂ）との間にそれぞれ配置されている。 The insulating member 4 is a member made of a resin for insulating between the electrode terminals 3 and 3 and the battery case 2, and as an insulating member having three different shapes, an external insulating member 7 (also called an insulator), an annular shape It consists of a gasket 8 and an internal insulating member 9. The insulating member 4 is disposed between each of the electrode terminals 3 and 3 and the battery case 2 (lid 2b).

外部絶縁部材７は、電池ケース２の外部（蓋体２ｂ上）に配置され、所定の樹脂（具体的には後述する）からなる平面視長方形状の絶縁部材である（図３参照）。すなわち、電極端子３・３と蓋体２ｂとの間に介装され、その間を電気的に絶縁するものである。 The external insulating member 7 is an insulating member that is disposed outside the battery case 2 (on the lid 2b) and is rectangular in a plan view made of a predetermined resin (specifically described later) (see FIG. 3). That is, it is interposed between the electrode terminals 3 and 3 and the lid 2b, and electrically insulates between them.

また、外部絶縁部材７は、平面視矩形状の凹部である基部嵌合部７ａと、平面視矩形状の凹部であるかしめ部嵌合部７ｂとを有する。図１（ｂ）に示すように、基部嵌合部７ａを有する部分は、かしめ部嵌合部７ｂを有する部分よりも大きい厚さ寸法となるように形成されており、側面視略Ｚ字状に屈曲した外部端子部材３ｂを配置できる。 The external insulating member 7 includes a base fitting portion 7a that is a concave portion having a rectangular shape in plan view, and a caulking portion fitting portion 7b that is a concave portion having a rectangular shape in plan view. As shown in FIG.1 (b), the part which has the base part fitting part 7a is formed so that it may become a thickness dimension larger than the part which has the crimp part fitting part 7b, and side view is substantially Z-shaped. The external terminal member 3b bent can be disposed.

基部嵌合部７ａは、バスバ締結部材３ｃの基部１４の形状（本実施形態では、四角柱状）に対応して外部絶縁部材７表面に穿設形成された平面視四角形状の凹部であり、バスバ締結部材３ｃの基部１４が嵌合される。これにより、バスバ締結部材３ｃは、その軸回りに回転不能な状態で外部絶縁部材７に固定されるとともに、バスバ締結部材３ｃの基部１４と蓋体２ｂとを電気的に絶縁している。バスバ締結部材３ｃの基部１４は、外部絶縁部材７の基部嵌合部７ａに保持されるので、バスバ締結部材３ｃにバスバを当接させ、バスバ締結部材３ｃのネジ部１３にナット等を締結したときに、バスバ締結部材３ｃが供回りすることを防止できる。 The base fitting portion 7a is a concave portion having a rectangular shape in a plan view formed in the surface of the external insulating member 7 so as to correspond to the shape of the base portion 14 of the bus bar fastening member 3c (in this embodiment, a quadrangular prism shape). The base 14 of the fastening member 3c is fitted. As a result, the bus bar fastening member 3c is fixed to the external insulating member 7 in a state in which the bus bar fastening member 3c cannot rotate about its axis, and electrically insulates the base portion 14 of the bus bar fastening member 3c and the lid 2b. Since the base portion 14 of the bus bar fastening member 3c is held by the base fitting portion 7a of the external insulating member 7, the bus bar is brought into contact with the bus bar fastening member 3c and a nut or the like is fastened to the screw portion 13 of the bus bar fastening member 3c. In some cases, the bus bar fastening member 3c can be prevented from rotating.

かしめ部嵌合部７ｂは、外部端子部材３ｂのシールかしめ部１２の形状（本実施形態では、矩形板状）に対応して外部絶縁部材７表面に穿設形成された平面視四角形状の凹部であり、外部絶縁部材７のシールかしめ部１２が嵌合される。また、かしめ部嵌合部７ｂの周囲には、所定幅を有するかしめ部側壁部７ｃが形成される。これにより、外部端子部材３ｂは、外部絶縁部材７に固定されるとともに、外部端子部材３ｂのシールかしめ部１２と蓋体２ｂとを電気的に絶縁している。また、かしめ部嵌合部７ｂの底部の略中央には、電極端子３（集電端子３ａ）のリベット部６を挿通するための円形状の挿通孔７ｄが形成されている。挿通孔７ｄには、当該挿通孔７ｄの周縁において外部絶縁部材７の外側（図２では下方）に向けてに突出するように形成された平面視環状で凸部状の厚肉部位である環状突出部７ｅが一体形成されている。かしめ部嵌合部７ｂに外部端子部材３ｂのシールかしめ部１２が嵌合されると、外部端子部材３ｂのリベット挿通孔１２ａは挿通孔７ｄに対応するように配置され、リベット部６を挿通可能な同じ内径の連通孔となる。こうして、外部絶縁部材７は、環状突出部７ｅが蓋体２ｂのリベット挿通孔２ｃに嵌めこまれた状態でリベット部６を挿通孔７ｄに挿通することで、環状突出部７ｅが集電端子３ａのリベット部６と蓋体２ｂのリベット挿通孔２ｃの内周面との間に介在される。これにより、集電端子３ａのリベット部６と蓋体２ｂとの間が絶縁される。 The caulking portion fitting portion 7b is a concave portion having a rectangular shape in plan view, which is formed in the surface of the external insulating member 7 so as to correspond to the shape of the seal caulking portion 12 of the external terminal member 3b (in this embodiment, a rectangular plate shape). The seal caulking portion 12 of the external insulating member 7 is fitted. A caulking portion side wall portion 7c having a predetermined width is formed around the caulking portion fitting portion 7b. Thereby, the external terminal member 3b is fixed to the external insulating member 7 and electrically insulates the seal caulking portion 12 of the external terminal member 3b and the lid 2b. A circular insertion hole 7d for inserting the rivet portion 6 of the electrode terminal 3 (collecting terminal 3a) is formed in the approximate center of the bottom portion of the caulking portion fitting portion 7b. The insertion hole 7d is an annular ring-shaped convex portion in a plan view that is formed so as to protrude toward the outside (downward in FIG. 2) of the external insulating member 7 at the periphery of the insertion hole 7d. The protrusion 7e is integrally formed. When the seal caulking portion 12 of the external terminal member 3b is fitted to the caulking portion fitting portion 7b, the rivet insertion hole 12a of the external terminal member 3b is arranged so as to correspond to the insertion hole 7d, and the rivet portion 6 can be inserted. The communication holes have the same inner diameter. Thus, the external insulating member 7 is inserted into the insertion hole 7d with the annular protrusion 7e fitted in the rivet insertion hole 2c of the lid 2b, so that the annular protrusion 7e is connected to the current collecting terminal 3a. Between the rivet portion 6 and the inner peripheral surface of the rivet insertion hole 2c of the lid 2b. Thereby, the rivet portion 6 of the current collecting terminal 3a and the lid 2b are insulated.

また、外部絶縁部材７は、前記電極端子３（集電端子３ｃ）のリベット部６を挿通するための挿通孔７ｄ周囲に形成される母材１５と、当該母材１５を除く部分と、からなる。当該母材１５を除く部分とは、母材１５以外の部分であって、具体的には、外部絶縁部材７の外周面７ｆ及び外周周縁部を少なくとも含む部分である。前記母材１５と前記母材１５を除く部分とは、二色成形により一体に形成される。すなわち、外部絶縁部材７では、図３に示すように、かしめ部嵌合部７ｂに開口形成された挿通孔７ｄの円形状もしくは楕円状の周縁部である母材１５と、当該母材１５を囲む外側の部分とでは異なる樹脂材料で構成され、それぞれ使われている樹脂材料が異なる。 The external insulating member 7 includes: a base material 15 formed around an insertion hole 7d for inserting the rivet portion 6 of the electrode terminal 3 (collecting terminal 3c); and a portion excluding the base material 15 Become. The part excluding the base material 15 is a part other than the base material 15, specifically, a part including at least the outer peripheral surface 7 f and the outer peripheral edge of the external insulating member 7. The base material 15 and the portion excluding the base material 15 are integrally formed by two-color molding. That is, in the external insulating member 7, as shown in FIG. 3, a base material 15 that is a circular or elliptical peripheral portion of the insertion hole 7d formed in the caulking portion fitting portion 7b, and the base material 15 It is comprised with a different resin material in the outer part which surrounds, and the resin material used for each differs.

母材１５を除く部分は、図９に示すように、絶縁部材（外部絶縁部材７）が溶接部に近接するため、レーザによる熱害を抑えることができる非芳香族化合物により形成することが好ましい。一方、母材１５は、前記非芳香族化合物よりもへたり特性が高い樹脂材料にて形成することが好ましい。ここで、「へたり」とは樹脂部材が受ける荷重によって弾性変形をこえ、塑性変形を有した状態になることをいう。また、本実施形態でいう「へたり特性」とは、具体的には応力緩和特性のことであり、後述する外部絶縁部材のシール性評価によって評価されるものである。また、「へたり特性」が高い樹脂材料とは、応力緩和によるへたりが少ない樹脂材料のことであり、換言すれば応力緩和特性が優れた樹脂材料ということである。この詳細については、後述する。 As shown in FIG. 9, since the insulating member (external insulating member 7) is close to the welded portion, the portion excluding the base material 15 is preferably formed of a non-aromatic compound that can suppress heat damage due to laser. . On the other hand, the base material 15 is preferably formed of a resin material having higher sag characteristics than the non-aromatic compound. Here, “sagging” means that the resin member undergoes elastic deformation due to the load received by the resin member and has a plastic deformation state. The “sagging characteristics” in the present embodiment is specifically stress relaxation characteristics, and is evaluated by evaluating the sealing performance of the external insulating member described later. Further, a resin material having high “sagging characteristics” refers to a resin material that has less sag due to stress relaxation, in other words, a resin material having excellent stress relaxation characteristics. Details of this will be described later.

環状ガスケット８は、電池ケース２の内部（蓋体２ｂ裏面）に配置され、所定の樹脂からなる円環板状の絶縁部材である。すなわち、電極端子３・３（集電端子３ａ・３ａ）と蓋体２ｂとの間に介装され、その間を電気的に絶縁するものである。また、環状ガスケット８は、蓋体２ｂと集電端子３ａの端子本体部５との間において、厚み方向に圧縮された状態で狭持されることで、リベット挿通孔２ｃから電解液が漏れないようにシールすることができる。環状ガスケット８の開口部には、集電端子３ａのリベット部６が挿通される。環状ガスケット８により、蓋体２ｂと集電端子３ａの端子本体部５との間の絶縁及びシールが行われる。
なお、環状ガスケット８に使用する樹脂材料としては、ＰＦＡ（パーフロロアルコキシアルカン）などの耐薬品性に強く、応力緩和によるへたりが少ない樹脂が望ましい。 The annular gasket 8 is an annular plate-like insulating member that is disposed inside the battery case 2 (the back surface of the lid 2b) and is made of a predetermined resin. That is, it is interposed between the electrode terminals 3 and 3 (current collection terminals 3a and 3a) and the lid 2b, and electrically insulates between them. The annular gasket 8 is sandwiched between the lid 2b and the terminal body 5 of the current collecting terminal 3a in a compressed state in the thickness direction, so that the electrolyte does not leak from the rivet insertion hole 2c. Can be sealed. The rivet portion 6 of the current collecting terminal 3 a is inserted through the opening of the annular gasket 8. The annular gasket 8 provides insulation and sealing between the lid 2b and the terminal body 5 of the current collecting terminal 3a.
The resin material used for the annular gasket 8 is preferably a resin that is strong in chemical resistance, such as PFA (perfluoroalkoxyalkane), and has less sag due to stress relaxation.

内部絶縁部材９は、電池ケース２の内部（蓋体２ｂ裏面）に配置され、所定の樹脂からなる平面視略長方形状の絶縁部材である。すなわち、電極端子３・３と蓋体２ｂとの間に介装され、その間を電気的に絶縁するものである。 The internal insulating member 9 is an insulating member that is disposed inside the battery case 2 (the back surface of the lid 2b) and is substantially rectangular in a plan view made of a predetermined resin. That is, it is interposed between the electrode terminals 3 and 3 and the lid 2b, and electrically insulates between them.

また、内部絶縁部材９は、蓋体当接部９ａと、当該蓋体当接部９ａから側方に延びる側方延出部（図示せず）と、により一体的に構成されている。 Further, the internal insulating member 9 is integrally configured by a lid contact portion 9a and a side extending portion (not shown) extending laterally from the lid contact portion 9a.

蓋体当接部９ａは、環状ガスケット８を収容する開口を有し、当該開口内に環状ガスケット８を収容した状態で配置されるとともに、蓋体２ｂと集電端子３ａの端子本体部５との間に配置される。これにより、蓋体２ｂと集電端子３ａの端子本体部５との間を絶縁できるとともに、リベット部６をかしめた際に環状ガスケット８の厚みを所定の厚みに規制して、圧縮不足によるシール性の低下や圧縮過剰によるシール部材の劣化を防止できる。蓋体当接部９ａには、その幅方向（図２の左右方向）外側端部に、下方に延出される側壁部９ｂを有する。
なお、本実施形態では、上述した環状ガスケット８と内部絶縁部材９を別体として構成したが、特に限定するものではなく、環状ガスケット８と内部絶縁部材９とを一体的に構成することもできる。 The lid abutting portion 9a has an opening for accommodating the annular gasket 8, and is disposed in a state where the annular gasket 8 is accommodated in the opening, and the lid body 2b and the terminal main body portion 5 of the current collecting terminal 3a, It is arranged between. Thereby, while being able to insulate between the cover body 2b and the terminal main-body part 5 of the current collection terminal 3a, when the rivet part 6 is crimped, the thickness of the annular gasket 8 is regulated to a predetermined thickness, and sealing due to insufficient compression It is possible to prevent the deterioration of the sealing member due to the deterioration of the property and excessive compression. The lid abutting portion 9a has a side wall portion 9b extending downward at an outer end portion in the width direction (left-right direction in FIG. 2).
In the present embodiment, the annular gasket 8 and the internal insulating member 9 described above are configured as separate bodies. However, the present invention is not particularly limited, and the annular gasket 8 and the internal insulating member 9 can also be configured integrally. .

側方延出部は、蓋体当接部９ａ及び側壁部９ｂの側方に延出され、蓋体２ｂと充放電要素１との間に配置される。これにより、蓋体２ｂと充放電要素１とが接触することを防止する。また、側方延出部を設けることにより、充放電要素１が膨張または位置ズレした場合にも、充放電要素１と、蓋体２ｂの略中央に設けられた安全弁２ｄとの間に、所定間隔を維持した状態を保つことができる。これにより、安全弁２ｄ付近のガスの流通性を確保して、充放電要素１で安全弁２ｄを塞ぐことを防止する。 The lateral extension portion extends laterally from the lid contact portion 9a and the side wall portion 9b, and is disposed between the lid body 2b and the charge / discharge element 1. Thereby, it is prevented that the cover body 2b and the charging / discharging element 1 contact. In addition, by providing the side extending portion, even when the charging / discharging element 1 expands or is displaced, a predetermined amount is provided between the charging / discharging element 1 and the safety valve 2d provided substantially at the center of the lid 2b. The state which maintained the space | interval can be maintained. Thereby, the gas flowability in the vicinity of the safety valve 2d is secured, and the charge / discharge element 1 is prevented from closing the safety valve 2d.

次に、本発明の特徴部分である外部絶縁部材７について具体的に説明する。
前述したように、リベット部６をかしめた際には、外部絶縁部材７が圧縮される。この外部絶縁部材７が経時変化によりへたると、環状ガスケット８にかかる面圧が低下し、シールアウトする場合がある。また、電極端子３と電池ケース２との絶縁を保つ外部絶縁部材７を構成する材料としては、樹脂材料を使用することが望ましい。これらを踏まえて、外部絶縁部材７としては、以下の項目を満足する必要がある。１）電池ケース２内の環状ガスケット８（シールガスケット樹脂）の圧縮率を維持するために、外部絶縁部材７は、応力緩和が少ない樹脂でなくてはならない。２）電池ケース２（ケース本体２ａ）と蓋体２ｂとの間を溶接するレーザ溶接の吸収・入熱等により劣化しないこと。３）電極端子３（バスバ締結部材３ｃ）とバスバの締結による空転・破壊がなきこと。上記項目をすべて満足するために本発明者は、鋭意検討を行って、本願発明の完成に至った。以下に、その経緯を説明する。 Next, the external insulating member 7 which is a characteristic part of the present invention will be specifically described.
As described above, when the rivet portion 6 is caulked, the external insulating member 7 is compressed. When the external insulating member 7 is sagged due to a change with time, the surface pressure applied to the annular gasket 8 may be reduced and seal-out may occur. Further, it is desirable to use a resin material as a material constituting the external insulating member 7 that maintains the insulation between the electrode terminal 3 and the battery case 2. Based on these, it is necessary for the external insulating member 7 to satisfy the following items. 1) In order to maintain the compressibility of the annular gasket 8 (seal gasket resin) in the battery case 2, the external insulating member 7 must be a resin with less stress relaxation. 2) The battery case 2 (case body 2a) and the lid 2b are not deteriorated by absorption / heat input of laser welding for welding between the lid 2b. 3) There is no idling / breakage due to the fastening of the electrode bar 3 (bus bar fastening member 3c) and the bus bar. In order to satisfy all the above items, the present inventor has intensively studied and has completed the present invention. The process will be described below.

まず、外部絶縁部材７としての要求レベルとして、少なくとも、外部絶縁部材７の経時変化による応力緩和が発生しても、シール性を保持する必要がある。そこで、この要求レベルを満たすために、上記項目１）２）に関して、応力緩和の少ない樹脂、レーザによる熱劣化しない樹脂という基準で、幾つかの樹脂について評価を行った。 First, as a required level of the external insulating member 7, it is necessary to maintain a sealing property even when stress relaxation due to a change with time of the external insulating member 7 occurs. Therefore, in order to satisfy this required level, several resins were evaluated with respect to the above items 1) and 2) on the basis of a resin with less stress relaxation and a resin that does not undergo thermal degradation by laser.

［外部絶縁部材のシール性評価］
上述した電池１０の構成において、外部絶縁部材７を後述する各樹脂を用いて作製し、この各樹脂からなる外部絶縁部材７を用いて、図１及び図２に示すような評価用密閉型電池を作製した。そうして、当該評価用密閉型電池のそれぞれについて電池ケース２（蓋体２ｂ）と外部絶縁部材７との間のシール性について調べるため、以下の試験によりシール性評価を行った。 [Sealability evaluation of external insulation members]
In the configuration of the battery 10 described above, the external insulating member 7 is made using each resin described later, and the evaluation-use sealed battery as shown in FIGS. 1 and 2 is made using the external insulating member 7 made of each resin. Was made. Then, in order to examine the sealing performance between the battery case 2 (lid 2b) and the external insulating member 7 for each of the evaluation sealed batteries, the sealing performance was evaluated by the following test.

具体的には、本実施形態における電池１０の構成において、外部絶縁部材７としてポリブチレンテレフタレート（ＰＢＴ）、ポリフタルアミド（ＰＰＡ）、ポリカーボネート＋ポリブチレンテレフタレート（ＰＣ＋ＰＢＴ）、ポリフェニレンエーテル／ポリアミド（ＰＰＥ／ＰＡ）、ポリフェニレンサルファイド（ＰＰＳ）、ポリアセタール（ＰＯＭ）、ポリエーテルエーテルケトン（ＰＥＥＫ）、ポリアミド６６（ＰＡ６６）、ポリカーボネート（ＰＣ）等の樹脂からなる外部絶縁部材を準備し、これらを用いて評価用密閉型電池を作製し、各評価用密閉型電池の保存試験と当該保存試験前後のシール性評価を行った。 Specifically, in the configuration of the battery 10 in the present embodiment, the polybutylene terephthalate (PBT), polyphthalamide (PPA), polycarbonate + polybutylene terephthalate (PC + PBT), polyphenylene ether / polyamide (PPE / Prepare external insulation members made of resin such as PA), polyphenylene sulfide (PPS), polyacetal (POM), polyetheretherketone (PEEK), polyamide 66 (PA66), polycarbonate (PC), etc. A sealed battery was produced, and a storage test of each evaluation sealed battery and a sealing property evaluation before and after the storage test were performed.

まず、Ｈｅ（ヘリウム）リークディテクターを用いて、保存試験前の各評価用密閉型電池のシール性評価を行った。具体的には、図４に示すように、電池ケース２内にＨｅ（ヘリウム）ガスを供給し、かしめる前の集電端子３ｃのリベット部６と外部端子部材３ｂのリベット挿通孔１２ａの隙間からリークするＨｅ（ヘリウム）ガスをＨｅ（ヘリウム）リークディテクターにより測定する。
その後、保存試験として、各評価用密閉型電池を、６０℃の恒温槽内において１０００時間保存した。保存試験後に、試験前と同様にＨｅ（ヘリウム）リークディテクターを用いて、保存試験後の各評価用密閉型電池のシール性評価を行った。良否の判定基準としては、保存試験前後のＨｅリーク量に１．０×１０²Ｐａ・ｍ³／ｓｅｃ以上の乖離がなく、１．０×１０^-5Ｐａ・ｍ³／ｓｅｃ以下を満たす場合、良判定（表１では○で示す）とする。 First, using a He (helium) leak detector, the sealing performance of each evaluation sealed battery before the storage test was evaluated. Specifically, as shown in FIG. 4, a gap between the rivet portion 6 of the current collecting terminal 3c and the rivet insertion hole 12a of the external terminal member 3b before the He (helium) gas is supplied into the battery case 2 and caulked. He (helium) gas leaking from the reactor is measured with a He (helium) leak detector.
Thereafter, as a storage test, each evaluation sealed battery was stored in a constant temperature bath at 60 ° C. for 1000 hours. After the storage test, the sealing performance of each sealed battery for evaluation after the storage test was evaluated using a He (helium) leak detector as before the test. As a criterion for pass / fail, the amount of He leak before and after the storage test is 1.0 × 10 ² Pa · m ³ / sec or more and satisfies 1.0 × 10 ⁻⁵ Pa · m ³ / sec or less. The good judgment (indicated by a circle in Table 1).

［レーザ溶接時の外部絶縁部材の熱劣化評価］
上述したように、溶接部が外部絶縁部材７に近接している場合、レーザ溶接の際に、外部絶縁部材７がレーザ波長を吸収したり、溶接の熱により熱劣化する。そこで、下記の評価を行った。 [Evaluation of thermal degradation of external insulation during laser welding]
As described above, when the welded portion is close to the external insulating member 7, the external insulating member 7 absorbs the laser wavelength or is thermally deteriorated by the heat of welding during laser welding. Therefore, the following evaluation was performed.

まず、蓋体２ｂを用意し、図５に示すように、当該蓋体２ｂ上に外部絶縁部材７の候補材料である上記各樹脂材料からなる矩形状かつ所定厚さの試験片を固定する。そして、当該試験片の長手方向に沿って、かつ試験片の長辺一端から１ｍｍ幅の間隔を有して、ＹＡＧレーザを用いて所定の条件（溶接速度：１０ｍｍ／ｍｉｎ、ビーム径：φ０．８ｍｍ、出力：６００Ｗ）で、レーザ光を試験片の長手方向に平行に照射してレーザ溶接を行った。良否の判定基準としては、φ０．１ｍｍ以上の黒点・気泡が１０ｍｍ²中に２個以上存在したらＮＧ（否判定：表１では×で示す）とする。すなわち、本実施形態の外部絶縁部材７として要求される性能としては、φ０．１ｍｍ以上の黒点・気泡が１０ｍｍ²中に２個未満である。 First, a lid 2b is prepared, and as shown in FIG. 5, a test piece having a rectangular shape and a predetermined thickness is fixed on the lid 2b. Then, along the longitudinal direction of the test piece and with an interval of 1 mm width from one end of the long side of the test piece, a predetermined condition (welding speed: 10 mm / min, beam diameter: φ0. 8 mm, output: 600 W), and laser welding was performed by irradiating a laser beam parallel to the longitudinal direction of the test piece. As a judgment criterion for acceptability, it is judged as NG (no judgment: indicated by x in Table 1) when two or more black spots / bubbles of φ0.1 mm or more exist in 10 mm ² . That is, as the performance required as the external insulating member 7 of the present embodiment, the number of black spots / bubbles of φ0.1 mm or more is less than ² in 10 mm ² .

表１の結果より、ＰＰＳ、ＰＥＥＫ等は優れたへたり特性を有するがレーザによる熱劣化が起こっている。一方、非芳香族化合物であるＰＯＭ、ＰＡ６６等はへたり特性はＰＰＳ、ＰＥＥＫ等より良くないがレーザによる熱劣化を起こさないことがわかる。そのため、外部絶縁部材７における母材１５としては、非芳香族化合物であるＰＯＭ、ＰＡ６６等よりもへたり特性が高い耐へたり樹脂材料（ＰＰＳ、ＰＥＥＫ等の応力緩和特性の優れた樹脂材料、つまり応力緩和の少ない樹脂材料）を用いて形成し、母材１５を除く部分は耐レーザ劣化樹脂材料（非芳香族化合物であるＰＯＭ、ＰＡ６６等のレーザによる熱劣化に強い樹脂材料）を用いて形成することが好ましい。このように、本実施形態の電池１０では、異なる機能を有する２種類の樹脂（耐へたり樹脂、耐レーザ劣化樹脂）からなる外部絶縁部材７を用いている。そのため、外部絶縁部材７は前述したように二色成形によって作製されることを特徴としている。 From the results shown in Table 1, PPS, PEEK, etc. have excellent sag characteristics, but thermal degradation due to laser occurs. On the other hand, it can be seen that the non-aromatic compounds such as POM and PA66 have a sag characteristic that is not better than that of PPS and PEEK, but do not cause thermal degradation by the laser. Therefore, as the base material 15 in the external insulating member 7, a sag resistant resin material (resin material having excellent stress relaxation characteristics such as PPS, PEEK, etc., which has higher sag characteristics than POM, PA66, etc., which are non-aromatic compounds, etc. In other words, a resin material with less stress relaxation is used, and the portion excluding the base material 15 is made of a laser-resistant resin material (resin material that is resistant to heat deterioration by a laser such as POM and PA66 which are non-aromatic compounds). It is preferable to form. As described above, the battery 10 according to the present embodiment uses the external insulating member 7 made of two types of resins (sag resistant resin and laser resistant resin) having different functions. Therefore, the external insulating member 7 is characterized by being produced by two-color molding as described above.

また、外部絶縁部材７を二色成形により作製する場合、母材１５を形成する耐へたり樹脂と母材１５以外の部位を形成する耐レーザ劣化樹脂との円周状もしくは楕円状の界面部において、界面剥離することが懸念される。界面剥離することにより耐レーザ劣化樹脂なる母材１５以外の部位があそび、そこに振動（車載用電池の場合は、車載振動）が加わると、例えば、図３の間隔Ｃで示す部分のような、耐レーザ劣化樹脂の薄肉部（細い部分）が割れ、絶縁部材としての絶縁性が低下する。さらに、耐へたり樹脂からなる母材１５と耐レーザ劣化樹脂からなる母材以外の部分との界面において、バスバ締結時に加わるトルクにより界面剥離が起こることも考えられる。そこで、本発明者は、耐へたり樹脂からなる母材１５の形状を図６（ｂ）に示すように、円状もしくは楕円状の母材１５の外周部にその外側に突出するように設けた複数（本実施形態では１０個）のギア歯１５ａを連設し、母材１５をギア形状にすることにより、バスバ締結時の応力を分散させ、界面剥離を抑制する構成を見出した。
一方、耐レーザ劣化樹脂からなる間隔Ｃが細くなると、亀裂が発生したり、破壊する可能性がある。そのため、以下のように、外部絶縁部材７の母材１５として好適な形状について検討を行った。
なお、図３における間隔Ｃは、（外部絶縁部材７の短片／２）−（耐へたり樹脂からなる母材１５の半径）を表すものである。 Further, when the external insulating member 7 is produced by two-color molding, a circumferential or elliptical interface between the anti-sagging resin that forms the base material 15 and the anti-laser-resistant resin that forms a part other than the base material 15 In this case, there is a concern about interface peeling. When a part other than the base material 15 which is a laser-resistant resin is formed by peeling off the interface, and vibration (in-vehicle vibration in the case of an in-vehicle battery) is applied thereto, for example, a portion indicated by a distance C in FIG. In addition, the thin portion (thin portion) of the laser resistant resin is broken, and the insulation as an insulating member is lowered. Furthermore, it is also conceivable that interface peeling occurs at the interface between the base material 15 made of sag-resistant resin and a portion other than the base material made of laser-resistant resin due to torque applied when the bus bar is fastened. Therefore, the present inventor provided the shape of the base material 15 made of sag resistant resin so as to protrude outward from the outer periphery of the circular or elliptical base material 15 as shown in FIG. In addition, the present inventors have found a configuration in which a plurality of (10 in the present embodiment) gear teeth 15a are connected in series and the base material 15 is formed in a gear shape to disperse stress at the time of bus bar fastening and suppress interface peeling.
On the other hand, if the interval C made of the laser-resistant resin becomes narrow, cracks may occur or break. Therefore, the shape suitable as the base material 15 of the external insulating member 7 was examined as follows.
In addition, the space | interval C in FIG. 3 represents (the short piece / 2 of the external insulation member / 2)-(the radius of the base material 15 which consists of sag-resistant resin).

図６に示すように、外部絶縁部材７の平面視において外部絶縁部材７の短片の長さをａ、耐へたり樹脂からなる母材１５のギア歯１５ａの歯たけをｂとする。前記外部絶縁部材７の短片の長さａを単位長として外部絶縁部材７の各部位の長さを表すと図６（ｂ）のようになる。すなわち、外部絶縁部材７の長手方向の中心線Ｄと外部絶縁部材７の短片との間隔は１／２ａ、中心線Ｄと母材１５のギア歯１５ａ一端（図６（ｂ）ではギア歯１５ａ上端）との間隔は１／４ａ、ギア歯１５ａ一端（図６（ｂ）ではギア歯１５ａ上端）と外部絶縁部材７の長辺（図６（ｂ）では外部絶縁部材７の上端）との間隔は１／４ａ、すなわち間隔Ｃ＋歯たけｂは１／４ａ、ギア歯１５ａ一端（図６（ｂ）ではギア歯１５ａ上端）とかしめ部側壁部７ｃとの間隔は３／２０ａ、及びかしめ部側壁部７ｃの幅の間隔は１／１０ａである。
なお、以下では、特に断りがない限り、母材１５とは、ギア歯１５ａを含むギア形状の母材とする。 As shown in FIG. 6, the length of the short piece of the external insulating member 7 in a plan view of the external insulating member 7 is a, and the tooth depth of the gear teeth 15a of the base material 15 made of sag resistant resin is b. When the length a of the short piece of the external insulating member 7 is a unit length, the length of each part of the external insulating member 7 is expressed as shown in FIG. That is, the distance between the longitudinal center line D of the external insulating member 7 and the short piece of the external insulating member 7 is 1 / 2a, and the center line D and one end of the gear tooth 15a of the base material 15 (the gear tooth 15a in FIG. 6B). The distance from the upper end is 1 / 4a, and one end of the gear tooth 15a (the upper end of the gear tooth 15a in FIG. 6B) and the long side of the external insulating member 7 (the upper end of the external insulating member 7 in FIG. 6B). The interval is 1 / 4a, that is, the interval C + toothb is 1 / 4a, the gear tooth 15a one end (the upper end of the gear tooth 15a in FIG. 6B) and the caulking portion side wall 7c is 3 / 20a, and the caulking portion The width interval of the side wall portion 7c is 1 / 10a.
In the following description, the base material 15 is a gear-shaped base material including the gear teeth 15a unless otherwise specified.

次に、上述した項目３）電極端子３（バスバ締結部材３ｃ）とバスバの締結による空転・破壊がなきこと、という要求レベル満たすかどうかを評価するために、以下の評価を行った。
まず、外部絶縁部材７の界面剥離評価を行うための評価用の試験片として、二色成形により、ＰＰＳからなる母材１５とＰＯＭからなる母材以外の部分と、からなる外部絶縁部材７であって、間隔Ｃの長さが０、０．０３ａ、０．０６ａ、０．０９ａ、０．１２ａ、０．１５ａとなる５種類の外部絶縁部材７を作製した。 Next, the following evaluation was performed in order to evaluate whether the required level of item 3) electrode terminal 3 (bus bar fastening member 3c) and the absence of idling / breakage due to the fastening of the bus bar is satisfied.
First, as an evaluation test piece for evaluating the interfacial peeling of the external insulating member 7, an external insulating member 7 including a base material 15 made of PPS and a portion other than the base material made of POM by two-color molding. Thus, five types of external insulating members 7 having the length of the interval C of 0, 0.03a, 0.06a, 0.09a, 0.12a, and 0.15a were produced.

［外部絶縁部材のバスバ締結時における界面剥離評価］
バスバ締結時のトルクによる界面剥離の発生の有無を調べるため、バスバ締結時を想定した外部絶縁部材７の界面剥離評価を行う。図７に示すように、外部絶縁部材７にバスバ締結部材３ｃの基部１４を嵌合し、耐へたり樹脂からなる母材１５のみを、所定の固定部材１６・１６で挟んで固定し、バスバ締結部材３ｃのネジ部１３に時計回りに所定のトルク［Ｎ・ｍ］を加えて、耐へたり樹脂からなる母材１５の界面剥離状態を調べた。ここで、外部絶縁部材として要求される性能としては、所定のトルクを加えた時に、母材１５の空転（界面剥離）がなきこと、かつ間隔Ｃの亀裂（破壊）のなきことである。すなわち、外部絶縁部材としての良否の判定基準としては、所定のトルクを加えた時に空転（界面剥離）があれば否判定（表２では、×で示す）とし、空転（界面剥離）がなければ良判定（表２では、○で示す）とする。さらに、所定のトルクを加えた時に亀裂・破壊があれば否判定（表２では、×で示す）とし、亀裂・破壊がなければ良判定（表２では、○で示す）とする。 [Evaluation of interfacial debonding when fastening external insulation member to bus bar]
In order to examine whether or not the interface peeling due to the torque at the time of bus bar fastening occurs, the interface peeling evaluation of the external insulating member 7 assuming the time of bus bar fastening is performed. As shown in FIG. 7, the base 14 of the bus bar fastening member 3c is fitted to the external insulating member 7, and only the base material 15 made of anti-sagging resin is sandwiched and fixed by predetermined fixing members 16 and 16, and the bus bar is fixed. A predetermined torque [N · m] was applied clockwise to the screw portion 13 of the fastening member 3c, and the interface peeling state of the base material 15 made of sag resistant resin was examined. Here, the performance required as the external insulating member is that the base material 15 does not run idle (interfacial separation) when a predetermined torque is applied, and that there is no crack (breakage) at the interval C. That is, as a judgment criterion for the quality of the external insulating member, if there is idling (interface separation) when a predetermined torque is applied, it is judged as negative (indicated by x in Table 2), and if there is no idling (interface separation). A good judgment (indicated by a circle in Table 2) is assumed. Further, if there is a crack / fracture when a predetermined torque is applied, it is judged as bad (indicated by x in Table 2), and if there is no crack / fracture, it is judged good (indicated by ◯ in Table 2).

表２では、比較例１、２、３（Ｃの長さ：０、０．０３ａ、０．０６ａ）では空転が発生し、比較例４（Ｃの長さ：０．１５ａ）では亀裂・破壊が発生した。一方、実施例１（Ｃの長さ：０．０９ａ）と実施例２（Ｃの長さ：０．１２ａ）においては、空転及び亀裂・破壊が発生しなかった。上記表２の結果より、間隔Ｃの長さの範囲としては、０．０９ａ≦Ｃ＜０．１２ａが好ましいことがわかった。また、ギア歯１５ａの歯たけｂは、間隔Ｃ＋歯たけｂ＝１／４ａの関係から、歯たけｂが０．１３ａ＜ｂ≦０．１６ａとなるように設定することが好ましい。 In Table 2, idling occurred in Comparative Examples 1, 2, and 3 (C length: 0, 0.03a, 0.06a), and cracking and fracture occurred in Comparative Example 4 (C length: 0.15a). There has occurred. On the other hand, in Example 1 (C length: 0.09a) and Example 2 (C length: 0.12a), idling and cracking / breaking did not occur. From the results of Table 2 above, it was found that 0.09a ≦ C <0.12a is preferable as the range of the length of the interval C. Further, the tooth depth b of the gear teeth 15a is preferably set so that the tooth depth b satisfies 0.13a <b ≦ 0.16a from the relationship of the interval C + the tooth depth b = 1 / 4a.

また、母材１５の構造としては図６（ｂ）で示した複数のギア歯１５ａを有するギア形状のもの以外で、トルクに対して、剛性を保てるような構成としては、図８（ａ）（ｂ）に示す構造などが挙げられる。図８（ａ）に示す母材１７を有する外部絶縁部材は、図５で示した母材１５よりも母材のギア歯の本数が少ない。そのため、図６で示した母材１５を有する外部絶縁部材７よりはトルクに対する強度が低下する。また、図８（ｂ）に示す母材１８を有する外部絶縁部材は、耐へたり樹脂からなる母材が平面視四角状である。そのため、間隔Ｃ以外にも耐レーザ劣化樹脂で薄い肉厚になる部分が存在する。その結果、図６で示した母材１５を有する外部絶縁部材７と比べて、トルクの荷重が耐へたり樹脂からなる母材１８の角部に集中するため、破断し易くなる。 Further, the structure of the base material 15 is not a gear shape having a plurality of gear teeth 15a shown in FIG. 6B, and the structure capable of maintaining rigidity against torque is shown in FIG. Examples include the structure shown in (b). The external insulating member having the base material 17 shown in FIG. 8A has fewer gear teeth of the base material than the base material 15 shown in FIG. Therefore, the strength against torque is lower than that of the external insulating member 7 having the base material 15 shown in FIG. Further, in the external insulating member having the base material 18 shown in FIG. 8B, the base material made of sag resistant resin has a square shape in plan view. For this reason, in addition to the interval C, there is a portion that is thin with the laser-resistant resin. As a result, as compared with the external insulating member 7 having the base material 15 shown in FIG. 6, the torque load is concentrated on the corners of the base material 18 which is resistant to resin and is easily broken.

以上で説明したように、本実施形態の電池１０は、外部絶縁部材７が、２種類の機能の異なる樹脂を用いた二色成形によって成形されており、このため、従来に比べて、シール性に優れ、かつ熱劣化に強い外部絶縁部材を備える。これにより、本実施形態の電池１０は、レーザ溶接時のレーザによる熱害の防止とシール性の確保を両立することができる。ひいては、本発明によれば、密閉型電池として、電池ケース２（筐体）内の機密性を良好に維持することが可能な構造を有する電池を提供することができる。 As described above, in the battery 10 of the present embodiment, the external insulating member 7 is formed by two-color molding using two types of resins having different functions. It has an external insulation member that is excellent in resistance to heat deterioration. Thereby, the battery 10 of this embodiment can achieve both prevention of thermal damage due to the laser during laser welding and ensuring of sealing performance. As a result, according to this invention, the battery which has a structure which can maintain the confidentiality in the battery case 2 (housing | housing) favorably as a sealed battery can be provided.

２電池ケース
２ａケース本体
２ｂ蓋体
３電極端子
４絶縁部材
６リベット部
７外部絶縁部材
７ｄ挿通孔
１０電池
１５母材
１５ａギア歯

2 Battery case 2a Case body 2b Lid 3 Electrode terminal 4 Insulating member 6 Rivet portion 7 External insulating member 7d Insertion hole 10 Battery 15 Base material 15a Gear teeth

Claims

In a sealed battery formed by integrating a battery case and electrode terminals made of a lid and a case body via an insulating member made of resin, and laser welding the lid and the case body,
The insulating member is
An insertion hole for inserting the electrode terminal;
A base material formed around the insertion hole;
A portion excluding the base material,
The portion excluding the base material is formed of POM or PA66 which is a non-aromatic compound, and the base material is formed of PPS or PEEK which is a resin material having higher characteristics than the non-aromatic compound. A sealed battery.

The sealed battery according to claim 1, wherein the base material and the portion excluding the base material are integrally formed by two-color molding.