【０００１】
【発明の属する技術分野】
本発明は、グロメットに関し、詳しくは、自動車に配索するワイヤハーネスに組みつけて、車体パネルの貫通穴に装着し、貫通穴の挿通部分におけるワイヤハーネスの保護および防水、防塵を図るものである。
【０００２】
【従来の技術】
従来、自動車のエンジンルームから車室内へ配索されるワイヤハーネスにはグロメットを装着して、エンジンルームと車室とを仕切る車体パネルの貫通穴にグロメットを取り付けて、貫通穴を通るワイヤハーネスの保護およびエンジンルーム側から車室への防水、防塵、遮音を図っている。
【０００３】
図５（Ａ）に示すように、この種のグロメット１はゴムまたはエラストマーからなり、小径筒部２と、この小径筒部２に連続する拡径筒部３を備え、拡径筒部３の大径側端部に車体係止凹部４を設けており、車体係止凹部４を挟む両側壁は、大径側が垂直壁の鍔部４ａで、対向する小径側は傾斜壁４ｂとなっている。上記グロメット１は、小径筒部２から拡径筒部３の中空部にワイヤハーネスＷ／Ｈを通し、小径筒部２の先端側でテープＴにより固着している。
そして、車体パネルＰの貫通穴Ｈへの装着作業は、小径筒部２より挿入し、傾斜壁４ｂを内方に潰すように変形させて貫通穴Ｈを通過させ、通過後に復帰する傾斜壁４ｂと鍔部４ａとを車体パネルＰの両面に密着させて、グロメット１の車体係止凹部４を車体パネルＰの貫通穴Ｈに装着している。
なお、上記構成からなるグロメットとしては特許文献１に記載のものがある。
【０００４】
【特許文献１】
特開２００１−２６３４９４号公報
【０００５】
【発明が解決しようとする課題】
上記構成からなるグロメット１は、装着すべき貫通穴Ｈに比し大径の傾斜壁４ｂの基部が貫通穴Ｈを通過する直前に最も大きな抵抗力が発生する。即ち、傾斜壁４ｂを圧縮方向に変形させながら貫通穴Ｈを通過させるために要する力は相当大きく、グロメット１の装着作業は非常に困難なものであった。そこで、傾斜壁４ｂの外周に潤滑油を塗布して挿入抵抗を軽減する方法もあるが、グロメット１の装着作業前に潤滑油が揮発もしくは流れ落ちてしまい十分な効果を発揮することができない場合があった。
【０００６】
また、図５（Ｂ）に示すように、貫通穴Ｈへのグロメット５の挿入固定部分に樹脂成型品のリング状インナー６を内嵌し、このインナー６に突設した弾性係止爪６ａを弾性変形させて貫通穴Ｈの周縁部に係止することでグロメット５を装着するようにしたものがある（特許文献２）。この方法によればグロメット５の装着力を低減できるが、グロメット５はゴム製の本体と別部材としてインナー６を有する２体構造となるためコスト高になるという問題があった。
【０００７】
【特許文献２】
特開２００２−３６９３４７号公報
【０００８】
本発明は上記した問題を解消せんとするもので、車体パネルの貫通穴へのグロメット装着の際に要する力を軽減すると共に、確実に嵌合固定できるようにしたグロメットを提供することを課題としている。
【０００９】
【課題を解決するための手段】
上記課題を解決するため、本発明では、小径筒部と、該小径筒部に連続する拡径筒部と、該拡径筒部の端縁に連続して設けた拡径筒部より大径の鍔部とを備え、これら小径筒部と拡径筒部に自動車用ワイヤハーネスを貫通させて取り付けた状態で、上記小径筒部側から車体パネルの貫通穴に挿入し、上記拡径筒部と鍔部との間の外周面に設けた係止凹部を上記貫通穴の周縁部に嵌合して車体パネルに係止するグロメットであって、
上記拡径筒部の最大外径を上記貫通穴の内径と略等しい寸法設定とする一方、上記小径筒部には上記大径筒部および鍔部の内周面と間隔を有するようにして鍔部より後方へ延びる押圧部を設け、該押圧部の外径は上記拡径筒部の内径寸法より大きい寸法設定とし、
上記押圧部を上記拡径筒部の内部空間に嵌入することで上記拡径筒部を押し広げて上記係止凹部を上記貫通穴の周縁部に嵌合可能としていることを特徴とするグロメットを提供している。
【００１０】
上記構成によれば、グロメットを車体パネルの貫通穴の定位置に装着する際、拡径筒部の最大外径と貫通穴の内径が略等しい寸法となっているため、拡径筒部を縮径方向に弾性に抗して圧縮変形させることなく、グロメットを所要の装着位置まで無理なく挿入することができる。その後、押圧部を拡径筒部の内部空間に嵌入すると、拡径筒部が押圧部により拡径方向に押し広げられ、これにより拡径筒部と鍔部との間の外周面に設けた係止凹部が貫通穴の周縁部に嵌合するため、車体パネルに対しグロメットを抜け止め状態で保持することができる。
更に具体的には、空間部への押圧部の嵌入前の状態において、鍔部の外径は車体パネルの貫通穴より僅かに大径寸法に設定しており、これにより押圧部の嵌入前に鍔部が貫通穴の周縁部に当接することでグロメットを所要の装着位置に位置決めすることができる。
【００１１】
また、上記押圧部は小径筒部に連続して内周方向へ折り返すと共に、上記鍔部より後方へ延設した保持筒部の外周に一体的に膨出形成する一方、上記保持筒部の後端部にはワイヤハーネスの外周にテープ巻き固定される固定部を設けている。 この構成とすると、押圧部はワイヤハーネスにテープ巻き固定された保持筒部と一体化されているので、大径筒部の空間部内への押圧部の嵌入操作は、ワイヤハーネスと共に保持筒部を小径筒部側へ引き込み、または押し込み操作することにより作業性よく行うことができる。
【００１２】
更に具体的には、上記押圧部は後端方へ向かうに従い拡径するテーパー面を備えた構成とするのが好ましい。このような構成によれば、押圧部を大径筒部の内部空間に嵌入する際、押圧部の外周テーパー面の作用により拡径筒部を徐々に押し広げながら無理なく押圧部を内部空間に嵌入することができる。
【００１３】
また、上記拡径筒部の大径側から鍔部に渉る内周面には上記押圧部が上記拡径筒部の内部空間に嵌入されたとき、押圧部の後端の段部に係合する係止突部を突設してもよい。これによれば、押圧部が大径筒部の内部空間に嵌入されたとき、係止突部が押圧部の後端の段部に係合するため、内部空間からの押圧部の抜け止め機能を発揮することができる。
【００１４】
上記係止突部は上記押圧部を受け入れるために後端方へ向けて拡径する案内面を備えるようにするのが好ましい。このようにすれば、内部空間への押圧部の嵌入操作をより一層円滑化することができる。
【００１５】
上記押圧部の後端部には、該押圧部が上記拡径筒部の内部空間に嵌入されたとき、上記係止突部に当接して上記拡径筒部の後端および鍔部の内方への変位を規制する膨出部を形成するのが好ましい。このように構成すれば、押圧部を大径筒部の内部空間へ嵌入したとき、係止突部が膨出部に当接することで鍔部の縮径方向の変形を規制することができ、よって、貫通穴からのグロメットの外れを確実に防止することができる。
【００１６】
上記押圧部のテーパー面には軸線方向に延びる複数の突条または凹溝を形成してもよい。このようにすれば、押圧部を大径筒部の内部空間へ嵌入操作する際、押圧部の外周と大径筒部の内周との接触面積が小さくなって、押圧部の嵌入操作を一層円滑化することができる。
【００１７】
【発明の実施の形態】
以下、本発明の実施形態を図面を参照して説明する。
図１乃至図３はグロメットの第１実施形態を示している。グロメット１０はゴムまたはエラストマーで一体成形しており、車体パネルＰの貫通穴Ｈへの挿入側前部となる小径筒部１１と、小径筒部１１の端部より円錐形状に拡径して後部側に連続して延びるの拡径筒部１２と、この拡径筒部１２の端縁に連続する鍔部１３と、小径筒部１１の先端に連続して内周方向へ折り返して後方へ延設した保持筒部１４とを備えている。
【００１８】
鍔部１３の外径は車体パネルＰの貫通穴Ｈの内径より僅かに大径寸法となるように設定し、鍔部１３の前方側の垂直面１３ａを貫通穴Ｈの周縁部への当接面としている。また、垂直面１３ａの周縁部には容易に弾性変形して車体パネルＰの周縁部に密着可能なリップ部１３ｂを前方へ向けて断面半円弧状に突設している。拡径筒部１２は大径側を肉厚とし、鍔部１３の手前位置の外周面に車体パネルＰの貫通穴Ｈに係止するための環状の係止凹部１２ａを設けている。拡径筒部１２の最大外径Ａは貫通穴Ｈを構成するバーリング部Ｈａの内径Ｂと略等しい寸法設定とし、グロメット１０の通常状態において拡径筒部１２を貫通穴Ｈに無理なく挿入できるようにしている。
また、拡径筒部１２の大径側から鍔部１３に渉る内周面には内方へ突出する係止突部１５を全周または所要間隔毎に突設している。この係止突部１５は後述する押圧部１６の後端の段部１６ａに係合する略垂直な係止面１５ａと、この係止面１５ａから後方へ至るに従いテーパー状に拡径する案内面１５ｂとを備えている。
【００１９】
小径筒部１１および内方へ折り返して延出する保持筒部１４は薄肉に形成され、保持筒部１４の前後動作により折り返し部１４ａが移動して小径筒部１１の長さを変化可能としている。保持筒部１４内の通路はワイヤハーネスＷ／Ｈを貫通させる貫通路１４ｂとされている。一方、保持筒部１４の後端部は鍔部１３より更に外方へ延出して長さ方向にスリット１７ａを切り込んだ固定部１７とし、ワイヤハーネスＷ／Ｈの外周にテープ巻き固定される部分としている。
【００２０】
小径筒部１１から延出された保持筒部１４の外周には、拡径筒部１２および鍔部１３の内周面とは間隔を有するようにして拡径方向に一体的に膨出すると共に鍔部１３より後方へ延びる押圧部１６を設けている。この押圧部１６は拡径筒部１２の内部空間１８に対応して後端方へ至るに従い拡径する円錐形状のテーパー面１６ｂとして、係止突部１５の案内面１５ｂと対応する形状とされ、その最大径部分の外径寸法Ｃは、内部空間１８の最も大径の内径寸法Ｄより大きい寸法設定としている。この寸法設定によって、押圧部１６を拡径筒部１２の内部空間１８内に嵌入したとき、拡径筒部１２および鍔部１３を弾性的に押し広げることが可能となっている。内部空間１８への押圧部１６の嵌入により拡径筒部１２および鍔部１３が拡径する寸法は、係止凹部１２ａが車体パネルＰの貫通穴Ｈの口縁部に嵌合したとき、貫通穴Ｈに対し係止凹部１２ａが拡径方向に弾性的に密着可能な寸法としている。即ち、押圧部１６の外径寸法Ｃと対応する内部空間１８の内径寸法Ｄとの差は、拡径筒部１２の最大外径Ａと係止凹部１２ａの内径寸法Ｅとの差以上の寸法設定（Ｃ−Ｄ≧＞Ａ−Ｅ）としている。このような寸法設定とすることで、貫通穴Ｈに対し係止凹部１２ａをガタつきなく嵌合させることができる。
【００２１】
押圧部１６の後端部には押圧部１６より小径の膨出部１９を一体的に周設している。膨出部１９は押圧部１６が拡径筒部１２の内部空間１８に嵌入されたとき、係止突部１５の先端が当接することで拡径筒部１２および鍔部１３の内方への変位を規制可能としている。
【００２２】
次に上記構成からなるグロメット１０の装着工程について説明する。先ず、図２（Ａ）に示すように、保持筒部１４にワイヤハーネスＷ／Ｈを貫通させると共に、固定部１７の外周からテープＴを巻き付けてワイヤハーネスＷ／Ｈの外周にグロメット１０を固定する。そして、室内側Ｘとエンジンルーム側Ｙを仕切る車体パネルＰの貫通穴Ｈに、室内側Ｘから小径筒部１１を押し込む。このとき、拡径筒部１２の最大外径Ａと貫通穴Ｈの内径Ｂは略等しいので、拡径筒部１２を無理に圧縮変形させることなく軽く押し込むことができる。そして、図２（Ｂ）に示すように、貫通穴Ｈの口縁部のバーリング部Ｈａに鍔部１３が当接することでグロメット１０の装着位置が決められる。このとき、リップ部１３ｂが車体パネルＰに押圧されて弾性変形することで車体パネルＰに密着した状態となる。
【００２３】
次に、図３（Ａ）に示すように、小径筒部１１側からワイヤハーネスＷ／Ｈを引っ張るか、または固定部１７側を押圧することにより押圧部１６を拡径筒部１２の内部空間１８へ押し込む。このとき保持筒部１４が小径筒部１１側に延びて折り返され、一方、押圧部１６のテーパー面１６ｂが係止突部１５の案内面１５ｂに案内されて、拡径筒部１２および鍔部１３を弾性的に押し広げながら押圧部１６が押し込まれる。このとき、グロメット１０の係止凹部１２ａも拡径するため車体パネルＰのバーリング部Ｈａが係止凹部１２ａに嵌入した状態となる。
【００２４】
次いで、図３（Ｂ）に示すように、押圧部１６が係止突部１５を乗り越えて内部空間１８内に完全に押し込まれたとき、段部１６ａに係止突部１５の係止面１５ａが後方側から係合するため、押圧部１６の後方抜け方向への移動が規制される状態となる。以上のように押圧部１６の内部空間１８への押し込み操作は、拡径筒部１２および鍔部１３を外周方向へ均等に押し広げるためのある程度の挿入力が必要となるが、拡径筒部１２および鍔部１３を縮径方向に圧縮操作する従来の方式に比較すれば、その反発力は小さく、グロメット１０装着時の作業負荷を大幅に低減することができる。
【００２５】
上記のようにして、拡径筒部１２の内部空間１８に押圧部１６が嵌入されると、拡径筒部１２の内径寸法Ｄより押圧部１６の外径寸法Ｃが大きいため、拡径筒部１２および鍔部１３は拡径方向に押圧された状態が維持されることになる。これにより、係止凹部１２ａはバーリング部Ｈａに対し密着した嵌合状態となり、よって、グロメット１０は車体パネルＰの貫通穴Ｈに安定的に固定される。
【００２６】
図４（Ａ）（Ｂ）はグロメット１１０の第２実施形態であり、押圧部１１６外周のテーパー面１１６ｂに軸方向に延びる複数本の突条または凹溝を形成することにより形成される分割接触面１２０を設けている。なお、その他の構成は第１実施形態と同様のため、同一符号を付してその説明を省略する。
上記のように分割接触面１２０を設けることで、押圧部１１６の押し込み時には、係止突部１５の案内面１５ｂとの接触面積が減少する結果、押圧部１１６の押し込み操作をより一層軽減することができる。
【００２７】
【発明の効果】
以上の説明より明らかなように、本発明によれば、拡径筒部の外周面を車体パネルの貫通穴によって縮径方向に強制圧縮することなく貫通穴に装着することができるため、車体パネルへのグロメットの取り付け作業の作業性を向上することができる。また、拡径筒部の内部空間内への押圧部の嵌入により、拡径筒部および鍔部を拡径させて係止凹部を貫通穴の口縁部に対し嵌合することができるので、グロメットを安定的に車体パネルに固定することができる。
【図面の簡単な説明】
【図１】本発明のグロメットの第１実施形態を示し、（Ａ）は後方から見た斜視図、（Ｂ）は断面図である。
【図２】（Ａ）（Ｂ）はワイヤハーネスに固定したグロメットの拡径筒部を車体パネルに装着する工程を示す断面図である。
【図３】（Ａ）（Ｂ）は車体パネルに装着した拡径筒部に対し押圧部を嵌入する工程を示す断面図である。
【図４】第２実施形態のグロメットを示し、（Ａ）は後方から見た斜視図、（Ｂ）は押圧部の断面図である。
【図５】（Ａ）（Ｂ）は従来例を示す図である。
【符号の説明】
Ｗ／Ｈ ワイヤハーネス
Ｔ テープ
Ｐ 車体パネル
Ｈ 貫通穴
１０、１１０ グロメット
１１ 小径筒部
１２ 拡径筒部
１２ａ 係止凹部
１３ 鍔部
１４ 保持筒部
１４ａ 折り返し部
１５ 係止突部
１６ 押圧部
１６ａ 段部
１６ｂ テーパー面
１７ 固定部
１８ 内部空間
１９ 膨出部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a grommet, and more specifically, it is assembled to a wire harness routed in an automobile and attached to a through-hole of a vehicle body panel, and the wire harness is protected, waterproof, and dust-proof at an insertion portion of the through-hole. .
[0002]
[Prior art]
Conventionally, a grommet is attached to a wire harness routed from an engine room of a car to a vehicle interior, and the grommet is attached to a through hole of a vehicle body panel that separates the engine room and the vehicle interior. It is intended to protect and waterproof, dustproof, and soundproof from the engine room side to the passenger compartment.
[0003]
As shown in FIG. 5A, this type of grommet 1 is made of rubber or elastomer, and includes a small diameter cylindrical portion 2 and a large diameter cylindrical portion 3 continuous to the small diameter cylindrical portion 2. The large-diameter side end portion is provided with a vehicle body locking recess 4, and the both side walls sandwiching the vehicle body locking recess 4 are vertical wall flanges 4 a and opposed small-diameter sides are inclined walls 4 b. . The grommet 1 passes through the wire harness W / H from the small-diameter cylindrical portion 2 to the hollow portion of the enlarged-diameter cylindrical portion 3 and is fixed by the tape T on the distal end side of the small-diameter cylindrical portion 2.
And the mounting operation to the through hole H of the vehicle body panel P is inserted from the small diameter cylindrical part 2, deformed so that the inclined wall 4b is crushed inward, is allowed to pass through the through hole H, and is returned after passing through the inclined wall 4b. And the flange 4a are brought into close contact with both surfaces of the vehicle body panel P, and the vehicle body locking recess 4 of the grommet 1 is mounted in the through hole H of the vehicle body panel P.
In addition, there exists a thing of the patent document 1 as a grommet which consists of the said structure.
[0004]
[Patent Document 1]
JP-A-2001-263494
[Problems to be solved by the invention]
The grommet 1 having the above configuration generates the greatest resistance immediately before the base portion of the inclined wall 4b having a large diameter as compared with the through hole H to be attached passes through the through hole H. That is, the force required to pass through the through-hole H while deforming the inclined wall 4b in the compression direction is quite large, and the grommet 1 mounting work is very difficult. Therefore, there is a method of reducing the insertion resistance by applying lubricating oil to the outer periphery of the inclined wall 4b. However, there is a case where the lubricating oil volatilizes or flows down before the grommet 1 is attached and the sufficient effect cannot be exhibited. there were.
[0006]
Further, as shown in FIG. 5 (B), a ring-shaped inner 6 made of a resin molded product is fitted into a portion where the grommet 5 is inserted and fixed in the through hole H, and an elastic locking claw 6a protruding from the inner 6 is provided. There is one in which the grommet 5 is attached by being elastically deformed and locked to the peripheral portion of the through hole H (Patent Document 2). According to this method, the mounting force of the grommet 5 can be reduced. However, since the grommet 5 has a two-body structure having the inner 6 as a separate member from the rubber main body, there is a problem that the cost is increased.
[0007]
[Patent Document 2]
JP 2002-369347 A
The present invention is intended to solve the above-described problem, and it is an object of the present invention to provide a grommet that can reduce the force required to attach a grommet to a through hole of a vehicle body panel and can be securely fitted and fixed. Yes.
[0009]
[Means for Solving the Problems]
In order to solve the above-described problems, in the present invention, a small-diameter cylindrical portion, a large-diameter cylindrical portion continuous to the small-diameter cylindrical portion, and a large-diameter cylindrical portion provided continuously at an edge of the large-diameter cylindrical portion In the state where the automobile wire harness is passed through and attached to the small-diameter cylindrical portion and the large-diameter cylindrical portion, the small-diameter cylindrical portion is inserted into the through hole of the vehicle body panel from the small-diameter cylindrical portion, A grommet that engages a peripheral portion of the through hole with a locking recess provided on the outer peripheral surface between the flange and the hook portion and locks it to the vehicle body panel,
The maximum outer diameter of the enlarged diameter cylindrical portion is set to be substantially equal to the inner diameter of the through hole, while the small diameter cylindrical portion is spaced from the inner peripheral surface of the larger diameter cylindrical portion and the flange portion. Provided with a pressing portion extending rearward from the portion, the outer diameter of the pressing portion is set to be larger than the inner diameter size of the above-mentioned expanded diameter cylindrical portion,
A grommet characterized in that the pressing portion is fitted into the inner space of the enlarged-diameter cylindrical portion, thereby expanding the enlarged-diameter cylindrical portion so that the locking recess can be fitted to the peripheral portion of the through hole. providing.
[0010]
According to the above configuration, when the grommet is mounted at a fixed position of the through hole of the vehicle body panel, the maximum outer diameter of the enlarged diameter cylindrical portion and the inner diameter of the through hole are substantially equal to each other. The grommet can be inserted without difficulty to the required mounting position without being compressed and deformed against elasticity in the radial direction. After that, when the pressing portion is inserted into the inner space of the enlarged diameter cylindrical portion, the enlarged diameter cylindrical portion is expanded in the radial expansion direction by the pressing portion, and thereby provided on the outer peripheral surface between the enlarged diameter cylindrical portion and the flange portion. Since the locking recess is fitted to the peripheral edge of the through hole, the grommet can be held in a state of being prevented from coming off from the vehicle body panel.
More specifically, the outer diameter of the collar portion is set to be slightly larger than the through hole of the vehicle body panel in a state before the pressing portion is inserted into the space portion. A grommet can be positioned in a required mounting position because a collar part contacts the peripheral part of a through-hole.
[0011]
In addition, the pressing portion is continuously folded back in the inner circumferential direction from the small-diameter cylindrical portion, and integrally bulges on the outer periphery of the holding cylindrical portion that extends rearward from the flange portion, while the rear of the holding cylindrical portion. At the end portion, a fixing portion is provided that is taped and fixed to the outer periphery of the wire harness. With this configuration, since the pressing portion is integrated with the holding cylinder portion that is tape-fixed to the wire harness, the pressing portion is inserted into the space portion of the large-diameter cylindrical portion together with the wire harness. It can be performed with good workability by pulling in or pushing into the small-diameter cylindrical portion.
[0012]
More specifically, it is preferable that the pressing portion has a tapered surface that increases in diameter toward the rear end. According to such a configuration, when the pressing portion is inserted into the internal space of the large-diameter cylindrical portion, the pressing portion is easily brought into the internal space while gradually expanding the enlarged diameter cylindrical portion by the action of the outer peripheral tapered surface of the pressing portion. Can be inserted.
[0013]
Further, when the pressing portion is fitted into the inner space of the enlarged diameter cylindrical portion from the large diameter side of the enlarged diameter cylindrical portion to the flange portion, the stepped portion at the rear end of the pressing portion is engaged. A mating locking protrusion may be provided. According to this, when the pressing portion is inserted into the internal space of the large-diameter cylindrical portion, the locking protrusion engages with the stepped portion at the rear end of the pressing portion, so that the pressing portion can be prevented from coming off from the internal space. Can be demonstrated.
[0014]
It is preferable that the locking protrusion has a guide surface that expands toward the rear end in order to receive the pressing portion. In this way, the operation of inserting the pressing portion into the internal space can be further facilitated.
[0015]
At the rear end of the pressing portion, when the pressing portion is fitted into the inner space of the enlarged diameter cylindrical portion, the rear end of the enlarged diameter cylindrical portion and the inside of the flange portion are brought into contact with the locking projection. It is preferable to form a bulging part that restricts the displacement in the direction. If constituted in this way, when the pressing part is inserted into the internal space of the large-diameter cylindrical part, it is possible to regulate the deformation in the diameter-reducing direction of the collar part by the locking projection coming into contact with the bulging part, Therefore, the grommet can be prevented from coming off from the through hole.
[0016]
A plurality of protrusions or grooves extending in the axial direction may be formed on the tapered surface of the pressing portion. In this way, when the pressing portion is inserted into the inner space of the large diameter cylindrical portion, the contact area between the outer periphery of the pressing portion and the inner periphery of the large diameter cylindrical portion is reduced, and the pressing portion is further inserted. It can be smoothed.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1 to 3 show a first embodiment of a grommet. The grommet 10 is integrally formed of rubber or elastomer, and has a small-diameter cylindrical portion 11 that is a front portion on the insertion side into the through hole H of the vehicle body panel P, and a rear portion that is expanded in a conical shape from the end portion of the small-diameter cylindrical portion 11. The enlarged diameter cylindrical portion 12 continuously extending to the side, the flange 13 continuing to the end edge of the enlarged diameter cylindrical portion 12, and the inner end of the small diameter cylindrical portion 11 are folded back in the inner circumferential direction and extended backward. And a holding cylinder portion 14 provided.
[0018]
The outer diameter of the flange 13 is set to be slightly larger than the inner diameter of the through hole H of the vehicle body panel P, and the vertical surface 13a on the front side of the flange 13 is brought into contact with the peripheral edge of the through hole H. It is a surface. Further, a lip portion 13b that is easily elastically deformed and can be brought into close contact with the peripheral portion of the vehicle body panel P is projected in a semicircular cross section in the forward direction at the peripheral portion of the vertical surface 13a. The enlarged diameter cylindrical portion 12 is thick on the large diameter side, and is provided with an annular locking recess 12a for locking to the through hole H of the vehicle body panel P on the outer peripheral surface of the front side of the collar portion 13. The maximum outer diameter A of the enlarged diameter cylindrical portion 12 is set to a size substantially equal to the inner diameter B of the burring portion Ha constituting the through hole H, and the enlarged diameter cylindrical portion 12 can be inserted into the through hole H without difficulty in the normal state of the grommet 10. I am doing so.
Further, locking projections 15 projecting inwardly are provided on the inner circumferential surface extending from the large diameter side of the enlarged diameter cylindrical portion 12 to the flange portion 13 at every circumference or at required intervals. The locking projection 15 includes a substantially vertical locking surface 15a that engages with a step 16a at the rear end of the pressing portion 16, which will be described later, and a guide surface that expands in a taper shape from the locking surface 15a to the rear. 15b.
[0019]
The small-diameter cylindrical portion 11 and the holding cylindrical portion 14 that folds inward and extends are formed thin, and the folding portion 14a is moved by the longitudinal movement of the holding cylindrical portion 14 so that the length of the small-diameter cylindrical portion 11 can be changed. . The passage in the holding cylinder portion 14 is a through passage 14b that penetrates the wire harness W / H. On the other hand, the rear end portion of the holding cylinder portion 14 extends further outward than the flange portion 13 to form a fixing portion 17 in which a slit 17a is cut in the length direction, and is a portion that is taped and fixed to the outer periphery of the wire harness W / H It is said.
[0020]
On the outer periphery of the holding cylinder part 14 extending from the small diameter cylinder part 11, the diameter expansion cylinder part 12 and the inner peripheral surface of the flange part 13 are integrally bulged in the diameter increasing direction so as to be spaced apart from each other. A pressing portion 16 extending rearward from the collar portion 13 is provided. The pressing portion 16 has a shape corresponding to the guide surface 15b of the locking projection 15 as a conical tapered surface 16b that expands in diameter toward the rear end corresponding to the internal space 18 of the diameter-expanding cylindrical portion 12. The outer diameter dimension C of the maximum diameter portion is set larger than the inner diameter dimension D of the largest diameter of the internal space 18. With this dimension setting, when the pressing portion 16 is fitted into the internal space 18 of the enlarged diameter cylindrical portion 12, the enlarged diameter cylindrical portion 12 and the flange portion 13 can be elastically pushed and expanded. The dimension in which the diameter-expanded cylindrical portion 12 and the flange portion 13 are expanded by fitting the pressing portion 16 into the internal space 18 is such that when the locking recess 12a is fitted to the rim of the through hole H of the vehicle body panel P, The locking recess 12a is dimensioned so that it can be elastically adhered to the hole H in the diameter increasing direction. That is, the difference between the outer diameter dimension C of the pressing portion 16 and the corresponding inner diameter dimension D of the internal space 18 is larger than the difference between the maximum outer diameter A of the enlarged diameter cylindrical portion 12 and the inner diameter dimension E of the locking recess 12a. It is set (C−D ≧> A−E). By setting the dimensions as described above, the locking recess 12a can be fitted into the through hole H without rattling.
[0021]
A bulging portion 19 having a smaller diameter than the pressing portion 16 is integrally provided around the rear end portion of the pressing portion 16. When the pressing portion 16 is fitted into the internal space 18 of the enlarged diameter cylindrical portion 12, the bulging portion 19 is brought into contact with the distal end of the locking projection 15 so that the enlarged diameter cylindrical portion 12 and the flange portion 13 are inward. Displacement can be regulated.
[0022]
Next, the mounting process of the grommet 10 having the above configuration will be described. First, as shown in FIG. 2 (A), the wire harness W / H is passed through the holding cylinder portion 14, and the tape T is wound from the outer periphery of the fixing portion 17 to fix the grommet 10 to the outer periphery of the wire harness W / H. To do. Then, the small-diameter cylindrical portion 11 is pushed from the indoor side X into the through hole H of the vehicle body panel P that partitions the indoor side X and the engine room side Y. At this time, since the maximum outer diameter A of the enlarged diameter cylindrical portion 12 and the inner diameter B of the through hole H are substantially equal, the enlarged diameter cylindrical portion 12 can be lightly pushed in without forcibly compressing and deforming. Then, as shown in FIG. 2B, the mounting position of the grommet 10 is determined by the flange portion 13 coming into contact with the burring portion Ha at the rim portion of the through hole H. At this time, the lip portion 13b is pressed against the vehicle body panel P and is elastically deformed so that the lip portion 13b is in close contact with the vehicle body panel P.
[0023]
Next, as shown in FIG. 3 (A), pulling the wire harness W / H from the small-diameter cylindrical part 11 side or pressing the fixed part 17 side causes the pressing part 16 to move to the inner space of the enlarged-diameter cylindrical part 12. Push into 18. At this time, the holding cylinder portion 14 extends toward the small-diameter cylinder portion 11 and is folded back. On the other hand, the tapered surface 16b of the pressing portion 16 is guided by the guide surface 15b of the locking projection 15 so that the enlarged-diameter cylinder portion 12 and the flange portion are provided. The pressing portion 16 is pushed in while elastically expanding 13. At this time, since the diameter of the locking recess 12a of the grommet 10 is increased, the burring portion Ha of the vehicle body panel P is fitted into the locking recess 12a.
[0024]
Next, as shown in FIG. 3 (B), when the pressing portion 16 gets over the locking projection 15 and is completely pushed into the internal space 18, the locking surface 15a of the locking projection 15 is inserted into the stepped portion 16a. Since it engages from the back side, it will be in the state by which the movement to the back omission direction of the press part 16 is controlled. As described above, the pressing operation of the pressing portion 16 into the internal space 18 requires a certain amount of insertion force for evenly expanding the expanded diameter cylindrical portion 12 and the flange portion 13 in the outer circumferential direction. Compared with the conventional method of compressing the 12 and the collar portion 13 in the diameter reducing direction, the repulsive force is small, and the work load when the grommet 10 is attached can be greatly reduced.
[0025]
As described above, when the pressing portion 16 is inserted into the inner space 18 of the enlarged diameter cylindrical portion 12, the outer diameter dimension C of the pressing portion 16 is larger than the inner diameter dimension D of the enlarged diameter cylindrical portion 12. The state where the portion 12 and the flange portion 13 are pressed in the diameter-expanding direction is maintained. As a result, the locking recess 12a is brought into a close fitting state with the burring portion Ha, and thus the grommet 10 is stably fixed to the through hole H of the vehicle body panel P.
[0026]
4A and 4B show a second embodiment of the grommet 110, which is a divided contact formed by forming a plurality of protrusions or grooves extending in the axial direction on the tapered surface 116b of the outer periphery of the pressing portion 116. FIG. A surface 120 is provided. Since other configurations are the same as those of the first embodiment, the same reference numerals are given and description thereof is omitted.
By providing the divided contact surface 120 as described above, when the pressing portion 116 is pushed in, the contact area between the locking projection 15 and the guide surface 15b decreases, and as a result, the pushing operation of the pressing portion 116 is further reduced. Can do.
[0027]
【The invention's effect】
As is clear from the above description, according to the present invention, the outer peripheral surface of the enlarged diameter cylindrical portion can be attached to the through hole without being forcedly compressed in the diameter reducing direction by the through hole of the vehicle body panel. The workability of attaching the grommet to the can be improved. Further, by fitting the pressing portion into the inner space of the enlarged diameter cylindrical portion, the enlarged diameter cylindrical portion and the flange portion can be expanded in diameter so that the locking recess can be fitted to the rim of the through hole. The grommet can be stably fixed to the vehicle body panel.
[Brief description of the drawings]
1A and 1B show a first embodiment of a grommet of the present invention, in which FIG. 1A is a perspective view seen from the rear, and FIG. 1B is a cross-sectional view.
FIGS. 2A and 2B are cross-sectional views showing a process of mounting a diameter-growing cylindrical portion of a grommet fixed to a wire harness on a vehicle body panel. FIGS.
FIGS. 3A and 3B are cross-sectional views showing a process of inserting a pressing portion into an enlarged cylindrical portion mounted on a vehicle body panel. FIGS.
4A and 4B show a grommet according to a second embodiment, in which FIG. 4A is a perspective view seen from the rear, and FIG. 4B is a cross-sectional view of a pressing portion.
5A and 5B are diagrams showing a conventional example.
[Explanation of symbols]
W / H Wire harness T Tape P Car body panel H Through hole 10, 110 Grommet 11 Small diameter cylindrical portion 12 Large diameter cylindrical portion 12a Locking concave portion 13 Hook portion 14 Holding cylindrical portion 14a Folding portion 15 Locking protrusion 16 Pressing portion 16a Step Part 16b taper surface 17 fixing part 18 internal space 19 bulging part
