JP7448337B2

JP7448337B2 - grommet

Info

Publication number: JP7448337B2
Application number: JP2019206305A
Authority: JP
Inventors: 光利木村
Original assignee: Yazaki Corp
Current assignee: Yazaki Corp
Priority date: 2019-11-14
Filing date: 2019-11-14
Publication date: 2024-03-12
Anticipated expiration: 2039-11-14
Also published as: JP2021083155A

Description

本発明は、弾性変形可能な筒状部を備えるグロメットに関する。 The present invention relates to a grommet having an elastically deformable cylindrical portion.

従来から、車両等に電線を配索する際の止水などを目的として、中空筒形状を有する弾性体から構成されたグロメットが提案されている。例えば、従来のグロメットの一つは、車両の車体からドアに向けて配索される電線が挿通された状態でドアの開閉に対応できるように、ドアの開閉に対応して湾曲可能な蛇腹状の筒状部を有している（例えば、特許文献１を参照）。 BACKGROUND ART Conventionally, grommet made of an elastic body having a hollow cylinder shape has been proposed for the purpose of water-stopping when wiring electric wires to a vehicle or the like. For example, one of the conventional grommets has a bellows shape that can be bent in response to the opening and closing of the door, so that the electric wire routed from the vehicle body to the door can be inserted into the grommet. (For example, see Patent Document 1).

特開２０１５－２０４２５４号公報Japanese Patent Application Publication No. 2015-204254

ところで、一般に、従来のグロメットの筒状部に電線を通す際には、筒状部を径方向外側に向けて押し広げて拡径した状態で、筒状部に電線が通されることになる。筒状部の拡径は、通常、専用の機器（いわゆる開閉機）を用いて行われる。具体的には、細い棒状の複数のアーム（爪）を拡径前の筒状部に挿入し、それら複数のアームを互いに離れるように筒状部の径方向外側に向けて移動させることで、筒状部が拡径されることになる。 By the way, in general, when passing an electric wire through the cylindrical part of a conventional grommet, the cylindrical part is pushed outward in the radial direction to expand its diameter, and then the electric wire is passed through the cylindrical part. . Expansion of the diameter of the cylindrical portion is usually performed using a dedicated device (a so-called opening/closing machine). Specifically, by inserting a plurality of thin rod-shaped arms (claws) into the cylindrical part before diameter expansion, and moving the arms radially outward of the cylindrical part so as to separate from each other, The diameter of the cylindrical portion will be expanded.

従来のグロメットの筒状部の内周面には、筒状部の蛇腹形状に対応した複数の凹凸（即ち、筒軸周りを周回する複数の突条）が存在する。そのため、開閉機のアームを筒状部に挿入する際、拡径前の筒状部の筒径がアームの太さに対して小さい場合などにおいて、アームが筒状部の内壁面に接触する可能性がある。例えば、アームの先端が、筒状部の内壁面に引っかかる場合がある。このような接触（引っかかり）は、筒状部の損傷の原因ともなり得る。一方、筒状部の内周面にアームが接触しないように過度に慎重に作業を行うと、作業に要する時間が増す原因となり得る。このように、グロメットの筒状部の損傷などを避けながら、アームの挿通作業の作業性（ひいては、グロメットを備えたワイヤハーネスの生産性）を向上させることは困難である。 The inner circumferential surface of the cylindrical portion of a conventional grommet has a plurality of unevenness (that is, a plurality of protrusions extending around the cylindrical axis) corresponding to the bellows shape of the cylindrical portion. Therefore, when inserting the arm of the switch into the cylindrical part, if the diameter of the cylindrical part before diameter expansion is smaller than the thickness of the arm, the arm may come into contact with the inner wall surface of the cylindrical part. There is sex. For example, the tip of the arm may get caught on the inner wall surface of the cylindrical portion. Such contact (catching) may also cause damage to the cylindrical portion. On the other hand, if the work is performed too carefully so that the arm does not come into contact with the inner circumferential surface of the cylindrical part, the time required for the work may increase. As described above, it is difficult to improve the workability of the arm insertion work (and thus the productivity of the wire harness provided with the grommet) while avoiding damage to the cylindrical portion of the grommet.

本発明の目的の一つは、グロメットが有する筒状部の損傷の抑制と、その筒状部に電線などを挿通させる作業の作業性の向上と、を両立可能なグロメット、の提供である。 One of the objects of the present invention is to provide a grommet that can both suppress damage to the cylindrical portion of the grommet and improve workability in inserting electric wires and the like through the cylindrical portion.

前述した目的を達成するために、本発明に係るグロメットは、下記［１］～［２］を特徴としている。
［１］
弾性変形可能な筒状部を備えるグロメットであって、
前記筒状部は、
均一な厚さを有する筒壁から構成され、当該筒状部の筒軸に向けて突出し且つ前記筒軸周りを周回する複数の突条を、前記筒壁によって構成し、
前記複数の前記突条の各々は、
前記筒軸を含む平面によって前記筒状部を切ったときの断面視において、第１平坦部と、第２平坦部と、前記第１平坦部と前記第２平坦部とを繋ぐ曲面部と、を有し、前記第１平坦部と前記筒軸とのなす角度である第１角度が前記第２平坦部と前記筒軸とのなす角度である第２角度よりも小さく、且つ、前記曲面部の前記筒軸に最も近い箇所が前記筒軸に沿って並ぶように配置される、ように構成され、
前記複数の前記突条の各々は、前記筒状部の前記筒軸に直交する平面内にて前記筒軸周りを周回する突条であり、
前記第２角度は、略９０度であり、
前記複数の前記突条の各々は、
前記断面視において、前記第１平坦部が属する仮想上の平面よりも前記第２平坦部から遠ざかる側に前記曲面部の一部が位置し、及び／又は、前記第２平坦部が属する仮想上の平面よりも前記第１平坦部から遠ざかる側に前記曲面部の一部が位置する、ように構成される、
グロメットであること。
［２］
上記［１］に記載のグロメットにおいて、
前記第１角度は、１０度以上８０度以下である、
グロメットであること。 In order to achieve the above-mentioned object, the grommet according to the present invention is characterized by the following [1] to [ 2 ].
[1]
A grommet including an elastically deformable cylindrical part,
The cylindrical part is
It is composed of a cylindrical wall having a uniform thickness, and the cylindrical wall constitutes a plurality of protrusions that protrude toward the cylindrical axis of the cylindrical part and revolve around the cylindrical axis,
Each of the plurality of protrusions is
In a cross-sectional view when the cylindrical part is cut by a plane including the cylindrical axis, a first flat part, a second flat part, and a curved part connecting the first flat part and the second flat part; a first angle formed by the first flat part and the cylinder axis is smaller than a second angle formed by the second flat part and the cylinder axis, and the curved surface part The parts closest to the cylindrical axis are arranged along the cylindrical axis,
Each of the plurality of protrusions is a protrusion that goes around the cylinder axis in a plane perpendicular to the cylinder axis of the cylindrical part,
the second angle is approximately 90 degrees;
Each of the plurality of protrusions is
In the cross-sectional view, a part of the curved surface portion is located on a side farther from the second flat portion than the hypothetical plane to which the first flat portion belongs, and/or a portion of the curved surface portion is located on the side farther away from the second flat portion than the hypothetical plane to which the first flat portion belongs, and/or A part of the curved surface part is located on a side farther from the first flat part than the plane of
Must be a grommet.
[ 2 ]
In the grommet described in [1] above,
The first angle is 10 degrees or more and 80 degrees or less,
Must be a grommet.

上記［１］の構成のグロメットによれば、弾性変形可能な筒状部の内周面には、筒軸周りを周回する複数の突条が構成されている。これら突条の各々は、断面視において、第１平坦部、第２平坦部、及び、第１平坦部と第２平坦部とを繋ぐ曲面部を有する。ここで、第１平坦部と筒軸とのなす角度である第１角度が、第２平坦部と筒軸とのなす角度である第２角度よりも小さい（例えば、図５を参照）。そのため、筒状部の第１平坦部側の開口端から開閉機のアームを挿入すれば、仮にアームの先端が筒状部の第１平坦部に触れたとしても、第１平坦部に及ぼされる力のうちの径方向外側に向かう分力により、第１平坦部（ひいては突条の全体）が径方向外側に向けて逃げるように変形する。よって、アームの引っかかりが生じ難い。 According to the grommet having the configuration [1] above, the inner circumferential surface of the elastically deformable cylindrical portion is provided with a plurality of protrusions that extend around the cylindrical axis. Each of these protrusions has a first flat part, a second flat part, and a curved part connecting the first flat part and the second flat part in a cross-sectional view. Here, the first angle, which is the angle between the first flat part and the cylinder axis, is smaller than the second angle, which is the angle between the second flat part and the cylinder axis (for example, see FIG. 5). Therefore, if the arm of the opening/closing machine is inserted from the open end on the side of the first flat part of the cylindrical part, even if the tip of the arm touches the first flat part of the cylindrical part, it will not affect the first flat part. Due to the radially outward component of the force, the first flat portion (and by extension, the entire protrusion) deforms so as to escape radially outwardly. Therefore, the arm is less likely to get caught.

また、筒状部の筒壁の厚さが均一であることから、アームによって筒状部が拡径されたとき、筒状部の全体が同程度に引き伸ばされることになる。更に、各々の曲面部の筒軸に最も近い箇所が筒軸に沿って並ぶように配置されていることからも、同様に、筒状部の拡径時に筒状部の全体が同程度に引き伸ばされやすい。よって、筒状部の何れかの箇所に過大な応力集中が生じることを抑制し、拡径時の筒状部の破損などを抑制できる。 Moreover, since the thickness of the cylindrical wall of the cylindrical part is uniform, when the cylindrical part is expanded in diameter by the arm, the entire cylindrical part is stretched to the same extent. Furthermore, since the parts of each curved surface section closest to the cylinder axis are arranged along the cylinder axis, the entire cylinder part is similarly stretched to the same extent when the diameter of the cylinder part is expanded. It's easy to get lost. Therefore, it is possible to suppress excessive stress concentration from occurring in any part of the cylindrical portion, and to suppress damage to the cylindrical portion during diameter expansion.

したがって、本構成のグロメットは、グロメットが有する筒状部に電線などを挿通させる作業の作業性に優れている。 Therefore, the grommet with this configuration has excellent workability in inserting an electric wire or the like into the cylindrical portion of the grommet.

なお、筒状部の筒壁の厚さが「均一」であるとは、グロメットの製造時に不可避的に生じ得る公差（いわゆる製造ばらつき）の範囲内において、その厚さが一様であることを表す。換言すると、筒状部の筒壁の幅が設計上で（例えば、設計図面に示される厚さの数値が）同じであることを表す。
更に、上記［１］の構成のグロメットによれば、突条の第２平坦部と筒軸とのなす第２角度が略９０度である。これにより、第２角度が９０度よりも過度に大きい場合に比べ、第１平坦部の径方向外側への変形（逃げ）を、第２平坦部が出来る限り妨げないようにすることができる。更に、第２角度が９０度よりも過度に小さい場合に比べ、例えばグロメットを射出成形する際、いわゆるアンダーカットを避けることができて金型から第２平坦部を分離する作業を容易にできる。
なお、第２角度が「略」９０度であるとは、グロメットの製造時に不可避的に生じ得る公差（いわゆる製造ばらつき）の範囲内において、第２角度が９０度前後の角度であることを表す。また、グロメット形成用の金型からの分離性を考慮した勾配（いわゆる、抜きテーパ）に起因する９０度からのズレは、「略」の範囲内であるとして許容し得ることを表す。換言すると、第２角度が設計上で（例えば、設計図面に示される第２角度の数値が）９０度であることを表す。 Note that the thickness of the cylindrical wall of the cylindrical part is "uniform", which means that the thickness is uniform within the range of tolerances (so-called manufacturing variations) that inevitably occur during grommet manufacturing. represent. In other words, it means that the width of the cylindrical wall of the cylindrical part is the same in design (for example, the thickness value shown in the design drawing).
Furthermore, according to the grommet having the configuration [1] above, the second angle between the second flat portion of the protrusion and the cylinder shaft is approximately 90 degrees. Thereby, compared to the case where the second angle is excessively larger than 90 degrees, it is possible to prevent the second flat part from interfering with the radially outward deformation (evacuation) of the first flat part as much as possible. Furthermore, compared to the case where the second angle is excessively smaller than 90 degrees, for example, when injection molding a grommet, so-called undercuts can be avoided and the work of separating the second flat part from the mold can be facilitated.
Note that the second angle being "approximately" 90 degrees means that the second angle is approximately 90 degrees within the range of tolerances (so-called manufacturing variations) that may inevitably occur during grommet manufacturing. . Further, the deviation from 90 degrees due to the slope (so-called punching taper) in consideration of separability from the mold for forming the grommet is acceptable as being within the range of "approximately". In other words, the second angle is 90 degrees in design (for example, the numerical value of the second angle shown in the design drawing).

上記［２］の構成のグロメットによれば、突条の第１平坦部と筒軸とのなす第１角度が１０度以上８０度以下である。これにより、筒状部の本来の機能（例えば、使用時に柔軟に湾曲可能であること）を保ちながら、開閉機のアームに接触した際の第１平坦部の変形（逃げ）を容易にすることができる。 According to the grommet having the configuration described in [ 2 ] above, the first angle formed between the first flat portion of the protrusion and the cylinder axis is 10 degrees or more and 80 degrees or less. This allows the first flat part to easily deform (escape) when it comes into contact with the arm of the opening/closing machine, while maintaining the original function of the cylindrical part (for example, being able to bend flexibly during use). Can be done.

本発明によれば、グロメットが有する筒状部に電線などを挿通させる作業の作業性に優れたグロメット、を提供できる。 According to the present invention, it is possible to provide a grommet with excellent workability in inserting an electric wire or the like into the cylindrical portion of the grommet.

以上、本発明について簡潔に説明した。更に、以下に説明される発明を実施するための形態（以下、「実施形態」という。）を添付の図面を参照して通読することにより、本発明の詳細は更に明確化されるであろう。 The present invention has been briefly described above. Furthermore, the details of the present invention will be further clarified by reading the mode for carrying out the invention (hereinafter referred to as "embodiment") described below with reference to the accompanying drawings. .

図１は、本発明の実施形態に係るグロメットを示す斜視図である。FIG. 1 is a perspective view showing a grommet according to an embodiment of the present invention. 図２は、図１に示すグロメットの筒状部を拡大した斜視図である。FIG. 2 is an enlarged perspective view of the cylindrical portion of the grommet shown in FIG. 図３は、図１に示すグロメットの筒状部のＡ－Ａ断面の斜視図である。FIG. 3 is a perspective view of the AA cross section of the cylindrical portion of the grommet shown in FIG. 図４は、図１に示すグロメットの筒状部のＡ－Ａ断面の正面図である。FIG. 4 is a front view of the AA cross section of the cylindrical portion of the grommet shown in FIG. 図５は、図４に示す筒状部の突条のＡ－Ａ断面を拡大した正面図である。FIG. 5 is an enlarged front view of the AA cross section of the protrusion of the cylindrical portion shown in FIG. 4. FIG. 図６は、開閉機の複数のアームを一方側の開口端からグロメットの筒状部に挿入する状態を示す図１のＡ－Ａ断面に相当する断面図である。FIG. 6 is a sectional view corresponding to the AA section in FIG. 1, showing a state in which a plurality of arms of the opening/closing machine are inserted into the cylindrical portion of the grommet from one open end. 図７は、筒状部に挿入した開閉機のアームが筒状部の突条の第１平坦部を押圧することで突条が変形した状態を示す図６に対応する断面図である。FIG. 7 is a cross-sectional view corresponding to FIG. 6 showing a state in which the protrusion of the cylindrical portion is deformed by the arm of the opening/closing machine inserted into the cylindrical portion pressing the first flat portion of the protrusion of the cylindrical portion.

＜実施形態＞
以下、図面を参照しながら、本発明の実施形態に係るグロメット１について説明する。グロメット１は、樹脂成形品であり、弾性変形可能な円筒状の筒状部１０を備えている。以下、説明の便宜上、図１等に示すように、筒状部１０の延在方向の「一方側」及び「他方側」を定義する。 <Embodiment>
Hereinafter, a grommet 1 according to an embodiment of the present invention will be described with reference to the drawings. The grommet 1 is a resin molded product and includes an elastically deformable cylindrical portion 10. Hereinafter, for convenience of explanation, "one side" and "the other side" in the extending direction of the cylindrical portion 10 will be defined as shown in FIG. 1 and the like.

筒状部１０の一方側の端部には、拡径部２０が一体に設けられている。拡径部２０は、筒状部１０より径が大きく、且つ、筒状部１０の一方側の端部から一方側に向かうにつれて徐々に拡径する略円錐台状の形状を有する。グロメット１は、典型的には、車両の車体からドアに向けて配索される電線の止水などを目的として、当該電線（図示省略）が筒状部１０に挿通され、拡径部２０が車体側の部材（図示省略）に接続され、且つ、筒状部１０の他方側の端部（図示省略）がドア側の部材（図示省略）に接続された状態で使用される。筒状部１０は、ドアの開閉に対応して自由に湾曲するように弾性変形可能となっている。 An enlarged diameter portion 20 is integrally provided at one end of the cylindrical portion 10 . The expanded diameter portion 20 has a diameter larger than that of the cylindrical portion 10 and has a generally truncated conical shape that gradually increases in diameter from one end of the cylindrical portion 10 toward the other side. Typically, the grommet 1 has a cylindrical portion 10 through which an electric wire (not shown) is inserted, and an enlarged diameter portion 20 for the purpose of water-stopping an electric wire routed from the vehicle body toward a door. It is used in a state where it is connected to a member on the vehicle body side (not shown), and the other end (not shown) of the cylindrical part 10 is connected to a member on the door side (not shown). The cylindrical portion 10 can be elastically deformed to freely curve in response to opening and closing of the door.

円筒状の筒状部１０は、図２～図４に示すように、蛇腹状の形状を有している。具体的には、図２及び図３に示すように、筒状部１０の外周面には、筒状部１０の延在方向に沿って、環状の突条１１と、環状の溝部１２とが交互に位置している。図３及び図４に示すように、筒状部１０の内周面には、筒状部１０の延在方向に沿って、突条１１に対応して設けられた環状の溝部１３と、溝部１２に対応して設けられた環状の突条１４とが交互に位置している。 The cylindrical portion 10 has a bellows-like shape, as shown in FIGS. 2 to 4. Specifically, as shown in FIGS. 2 and 3, an annular protrusion 11 and an annular groove 12 are formed on the outer peripheral surface of the cylindrical portion 10 along the extending direction of the cylindrical portion 10. located alternately. As shown in FIGS. 3 and 4, the inner circumferential surface of the cylindrical portion 10 has an annular groove 13 provided corresponding to the protrusion 11 along the extending direction of the cylindrical portion 10, and a groove 12 and annular protrusions 14 provided corresponding to the protrusions 12 are alternately located.

図４に示すように、筒状部１０の筒壁の厚さは、筒状部１０全体に亘って均一となっている。ここで、筒状部１０の筒壁の厚さが「均一」であるとは、グロメット１の製造時に不可避的に生じ得る公差（いわゆる製造ばらつき）の範囲内において、その厚さが一様であることを表す。換言すると、筒状部１０の筒壁の幅が設計上で（例えば、設計図面に示される厚さの数値が）一様であることを表す。 As shown in FIG. 4, the thickness of the cylindrical wall of the cylindrical portion 10 is uniform over the entire cylindrical portion 10. As shown in FIG. Here, the thickness of the cylindrical wall of the cylindrical portion 10 is "uniform" within the range of tolerances (so-called manufacturing variations) that inevitably occur during the manufacturing of the grommet 1. express something. In other words, the width of the cylindrical wall of the cylindrical portion 10 is uniform in design (for example, the thickness value shown in the design drawing).

以下、筒状部１０の内周面に設けられた複数の突条１４に着目する。図４及び図５に示すように、複数の突条１４の各々は、筒状部１０の筒軸Ａｘを通る平面によって筒状部１０を切ったときの断面視において、一方側の第１平坦部１５と、他方側の第２平坦部１６と、第１平坦部１５と第２平坦部１６とを繋ぐ曲面部１７と、で構成されている。複数の突条１４の各々は、曲面部１７の頂部１８（筒軸Ａｘに最も近い箇所）が筒軸Ａｘに沿って平行に並ぶように配置されている（図４参照）。 Hereinafter, attention will be paid to the plurality of protrusions 14 provided on the inner peripheral surface of the cylindrical portion 10. As shown in FIGS. 4 and 5, each of the plurality of protrusions 14 has a first flat surface on one side in a cross-sectional view when the cylindrical portion 10 is cut along a plane passing through the cylindrical axis Ax of the cylindrical portion 10. portion 15, a second flat portion 16 on the other side, and a curved portion 17 connecting the first flat portion 15 and the second flat portion 16. Each of the plurality of protrusions 14 is arranged such that the top portion 18 (the portion closest to the cylinder axis Ax) of the curved surface portion 17 is arranged in parallel along the cylinder axis Ax (see FIG. 4).

図５に示すように、第１平坦部１５と筒軸Ａｘとのなす角度θ１は、第２平坦部１６と筒軸Ａｘとのなす角度θ２よりも小さい。本例では、角度θ１は、略４５度であり、角度θ２は、略９０度である。角度θ１は１０度以上８０度以下であることが好ましい。ここで、角度θ２が「略」９０度であるとは、グロメット１の製造時に不可避的に生じ得る公差（いわゆる製造ばらつき）の範囲内において、角度θ２が９０度前後の角度であることを表す。また、グロメット１成形用の金型からの分離性を考慮した勾配（いわゆる抜きテーパ）に起因する９０度からのズレは、「略」の範囲内であるとして許容し得ることを表す。換言すると、角度θ２が設計上で（例えば、設計図面に示される角度θ２の数値が）９０度であることを表す。角度θ１についても同様である。 As shown in FIG. 5, the angle θ1 between the first flat portion 15 and the cylinder axis Ax is smaller than the angle θ2 between the second flat portion 16 and the cylinder axis Ax. In this example, the angle θ1 is approximately 45 degrees, and the angle θ2 is approximately 90 degrees. The angle θ1 is preferably 10 degrees or more and 80 degrees or less. Here, the angle θ2 being "approximately" 90 degrees means that the angle θ2 is around 90 degrees within the range of tolerances (so-called manufacturing variations) that inevitably occur during the manufacturing of the grommet 1. . Furthermore, the deviation from 90 degrees due to the slope (so-called punching taper) that takes into consideration the separability from the mold for molding the grommet 1 is acceptable as being within the range of "approximately". In other words, the angle θ2 is 90 degrees in design (for example, the numerical value of the angle θ2 shown in the design drawing). The same applies to the angle θ1.

図５に示すように、複数の突条１４の各々は、筒状部１０の筒軸Ａｘを通る平面によって筒状部１０を切ったときの断面視において、曲面部１７全体が、第１平坦部１５が属する仮想上の平面Ｐ１よりも第２平坦部１６に近い側（他方側）に位置し、且つ、第２平坦部１６が属する仮想上の平面Ｐ２よりも第１平坦部１５に近い側（一方側）に位置する、ように構成されている。換言すれば、曲面部１７全体は、仮想上の平面Ｐ１よりも第１平坦部１５側（一方側）には突出せず、且つ、仮想上の平面Ｐ２よりも第２平坦部１６側（他方側）には突出していない。 As shown in FIG. 5, each of the plurality of protrusions 14 has a curved portion 17 whose entire curved surface portion 17 has a first flat surface in a cross-sectional view when the cylindrical portion 10 is cut along a plane passing through the cylindrical axis Ax of the cylindrical portion 10. Located closer to the second flat portion 16 (on the other side) than the imaginary plane P1 to which the portion 15 belongs, and closer to the first flat portion 15 than the imaginary plane P2 to which the second flat portion 16 belongs. It is located on one side (one side). In other words, the entire curved surface portion 17 does not protrude from the imaginary plane P1 toward the first flat portion 15 (one side), and from the imaginary plane P2 toward the second flat portion 16 (the other side). side) is not prominent.

次いで、グロメット１の筒状部１０に電線を通す際の作業について説明する。グロメット１の筒状部１０に電線を通す際には、グロメット１の筒状部１０を径方向外側に向けて押し広げて拡径した状態で、筒状部１０に電線が通されることになる。筒状部１０を径方向外側に向けて押し広げるためには、図６に示すように、専用の開閉機３０が使用される。 Next, the operation for passing the electric wire through the cylindrical portion 10 of the grommet 1 will be explained. When passing an electric wire through the cylindrical part 10 of the grommet 1, the cylindrical part 10 of the grommet 1 is pushed outward in the radial direction to expand its diameter, and then the electric wire is passed through the cylindrical part 10. Become. In order to push the cylindrical part 10 outward in the radial direction, a dedicated opening/closing machine 30 is used, as shown in FIG.

具体的には、開閉機３０の細い棒状の複数のアーム３１を、一方側の開口端から拡径前の筒状部１０に挿入し、それら複数のアーム３１を互いに離れるように筒状部１０の径方向外側に向けて移動させることで、筒状部１０が拡径される。 Specifically, a plurality of thin rod-shaped arms 31 of the opening/closing machine 30 are inserted into the cylindrical portion 10 before diameter expansion from one open end, and the plurality of arms 31 are separated from each other by the cylindrical portion 10. By moving radially outward, the diameter of the cylindrical portion 10 is expanded.

このように、開閉機３０のアーム３１を一方側の開口端から筒状部１０に挿入する際、特に拡径前の筒状部１０の筒径が小さいと、アーム３１の先端が、筒状部１０の突条１４における一方側の領域に位置する第１平坦部１５に接触する場合がある。アーム３１の先端が筒状部１０の第１平坦部１５に触れたとき、第１平坦部１５に及ぼされる力のうちの径方向外側に向かう分力により、図７に示すように、第１平坦部１５（ひいては突条１４の全体）が径方向外側に向けて逃げるように変形する。 In this way, when inserting the arm 31 of the opening/closing machine 30 into the cylindrical part 10 from the open end on one side, especially if the diameter of the cylindrical part 10 before diameter expansion is small, the tip of the arm 31 will be inserted into the cylindrical part 10. The first flat portion 15 located on one side of the protrusion 14 of the portion 10 may come into contact with the first flat portion 15 . When the tip of the arm 31 touches the first flat part 15 of the cylindrical part 10, the component of the force exerted on the first flat part 15 directed outward in the radial direction causes the first flat part 15 to move as shown in FIG. The flat portion 15 (and thus the entire protrusion 14) deforms so as to escape radially outward.

このとき、第１平坦部１５と筒軸Ａｘとのなす角度θ１が、第２平坦部１６と筒軸Ａｘとのなす角度θ２よりも小さいこと（図５参照）に起因して、そうでない場合と比べて、第１平坦部１５（ひいては突条１４の全体）が径方向外側に向けて逃げるように変形し易い。更に、突条１４の曲面部１７全体が、仮想上の平面Ｐ１よりも第１平坦部１５側（一方側）には突出していないこと（図５参照）に起因して、第１平坦部１５が径方向外側に逃げるように変形した後、アーム３１の先端が曲面部１７に引っかかることがない。更に、仮想上の平面Ｐ２よりも第２平坦部１６側（他方側）には突出していないこと（図５参照）に起因して、第１平坦部１５が径方向外側に逃げるように変形するとき、曲面部１７が他方側に隣接する第１平坦部１５に接触して第１平坦部１５の変形を妨げることがない。以上より、アーム３１の引っかかりが生じ難いので、アーム３１の挿通作業が極めて行い易く、且つ、アーム３１のひっかかりに起因する筒状部１０の損傷も生じ難い。 At this time, if this is not the case due to the fact that the angle θ1 between the first flat portion 15 and the cylinder axis Ax is smaller than the angle θ2 between the second flat portion 16 and the cylinder axis Ax (see FIG. 5), Compared to this, the first flat portion 15 (and by extension, the entire protrusion 14) is easily deformed so as to escape radially outward. Further, since the entire curved surface portion 17 of the protrusion 14 does not protrude toward the first flat portion 15 side (one side) from the imaginary plane P1 (see FIG. 5), the first flat portion 15 After deforming so as to escape radially outward, the tip of the arm 31 does not get caught on the curved surface portion 17. Further, since the first flat part 15 does not protrude toward the second flat part 16 (the other side) from the virtual plane P2 (see FIG. 5), the first flat part 15 deforms to escape radially outward. At this time, the curved surface portion 17 does not contact the first flat portion 15 adjacent to the other side and prevent the first flat portion 15 from deforming. As described above, since the arm 31 is less likely to get caught, the insertion work of the arm 31 is extremely easy to perform, and damage to the cylindrical portion 10 due to the arm 31 getting caught is also less likely to occur.

更には、筒状部１０の筒壁の厚さが均一であることから、アーム３１によって筒状部１０が拡径されたとき、筒状部１０の全体が同程度に引き伸ばされることになる。換言すると、筒状部１０の何れかの箇所に過大な応力集中が生じることを抑制し、拡径時の筒状部１０の破損などを抑制できる。更に、突条１４の各々の曲面部１７の頂部１８が、筒軸Ａｘに沿って並ぶように配置されているため、アーム３１を筒状部１０に更に挿入し易い。このように、グロメット１は、筒状部１０に電線などを挿通させる作業の作業性に優れている。 Furthermore, since the thickness of the cylindrical wall of the cylindrical portion 10 is uniform, when the cylindrical portion 10 is expanded in diameter by the arm 31, the entire cylindrical portion 10 is stretched to the same extent. In other words, it is possible to prevent excessive stress concentration from occurring in any part of the cylindrical portion 10, and to suppress damage to the cylindrical portion 10 during diameter expansion. Furthermore, since the top portions 18 of each curved surface portion 17 of the protrusion 14 are arranged so as to be aligned along the cylinder axis Ax, it is easier to insert the arm 31 into the cylinder portion 10. In this way, the grommet 1 has excellent workability in inserting electric wires and the like into the cylindrical portion 10.

＜作用・効果＞
以上、本実施形態に係るグロメット１によれば、弾性変形可能な筒状部１０の内周面には、筒軸Ａｘ周りを周回する複数の突条１４が構成されている。これら突条１４の各々は、断面視において、第１平坦部１５、第２平坦部１６、及び、第１平坦部１５と第２平坦部１６とを繋ぐ曲面部１７を有する。ここで、第１平坦部１５と筒軸Ａｘとのなす角度θ１が、第２平坦部１６と筒軸Ａｘとのなす角度θ２よりも小さい（図５参照）。そのため、筒状部１０の第１平坦部１５側（一方側）の開口端から開閉機３０のアーム３１を挿入すれば、アーム３１の先端が筒状部１０の第１平坦部１５に触れたとき、第１平坦部１５に及ぼされる力のうちの径方向外側に向かう分力により、第１平坦部１５（ひいては突条１４の全体）が径方向外側に向けて逃げるように変形する。よって、アーム３１の引っかかりが生じ難い。 <Action/Effect>
As described above, according to the grommet 1 according to the present embodiment, a plurality of protrusions 14 are formed on the inner circumferential surface of the elastically deformable cylindrical portion 10, and extend around the cylindrical axis Ax. Each of these protrusions 14 has a first flat part 15, a second flat part 16, and a curved part 17 connecting the first flat part 15 and the second flat part 16 in cross-sectional view. Here, the angle θ1 between the first flat portion 15 and the cylinder axis Ax is smaller than the angle θ2 between the second flat portion 16 and the cylinder axis Ax (see FIG. 5). Therefore, when the arm 31 of the switch 30 is inserted from the open end on the first flat part 15 side (one side) of the cylindrical part 10, the tip of the arm 31 touches the first flat part 15 of the cylindrical part 10. At this time, due to the radially outward component of the force applied to the first flat part 15, the first flat part 15 (and by extension, the entire protrusion 14) deforms so as to escape radially outward. Therefore, the arm 31 is less likely to get caught.

また、筒状部１０の筒壁の厚さが均一であることから、アーム３１によって筒状部１０が拡径されたとき、筒状部１０の全体が同程度に引き伸ばされることになる。換言すると、筒状部１０の何れかの箇所に過大な応力集中が生じることを抑制し、拡径時の筒状部１０の破損などを抑制できる。更に、各々の曲面部１７の筒軸Ａｘに最も近い頂部１８が、筒軸Ａｘに沿って並ぶように配置されているため、アーム３１を筒状部１０に更に挿入し易いことになる。したがって、本実施形態に係るグロメット１は、グロメット１が有する筒状部１０に電線などを挿通させる作業の作業性に優れている。 Further, since the thickness of the cylindrical wall of the cylindrical portion 10 is uniform, when the diameter of the cylindrical portion 10 is expanded by the arm 31, the entire cylindrical portion 10 is stretched to the same extent. In other words, it is possible to prevent excessive stress concentration from occurring in any part of the cylindrical portion 10, and to suppress damage to the cylindrical portion 10 during diameter expansion. Furthermore, since the top portions 18 of each curved surface portion 17 closest to the cylinder axis Ax are arranged so as to line up along the cylinder axis Ax, it becomes easier to insert the arm 31 into the cylinder portion 10. Therefore, the grommet 1 according to the present embodiment has excellent workability in inserting an electric wire or the like into the cylindrical portion 10 of the grommet 1.

更に、本実施形態に係るグロメット１によれば、筒状部１０の突条１４が有する曲面部１７が、断面視において、第１平坦部１５が属する（例えば、第１平坦部１５の表面を延長した）仮想上の平面Ｐ１よりも、第２平坦部１６に近い側に存在する（図５参照）。換言すると、曲面部１７は、その仮想上の平面Ｐ１よりも第１平坦部１５側には突出しない。よって、開閉機３０のアーム３１が一方側から挿通向きに進行しながら第１平坦部１５に接触したとき、第１平坦部１５が径方向外側に逃げるように変形した後、アーム３１の先端が曲面部１７に引っかかることがない。その結果、本実施形態に係るグロメット１は、グロメット１が有する筒状部１０に電線などを挿通させる作業の作業性に優れている。 Furthermore, according to the grommet 1 according to the present embodiment, the curved surface portion 17 of the protrusion 14 of the cylindrical portion 10 includes the first flat portion 15 in a cross-sectional view (for example, the surface of the first flat portion 15 is It exists on the side closer to the second flat part 16 than the imaginary plane P1 (extended) (see FIG. 5). In other words, the curved surface portion 17 does not protrude further toward the first flat portion 15 than the virtual plane P1. Therefore, when the arm 31 of the opening/closing machine 30 contacts the first flat part 15 while moving in the insertion direction from one side, the first flat part 15 deforms so as to escape radially outward, and then the tip of the arm 31 There is no chance of getting caught on the curved surface portion 17. As a result, the grommet 1 according to the present embodiment has excellent workability in inserting an electric wire or the like into the cylindrical portion 10 of the grommet 1.

更に、本実施形態に係るグロメット１によれば、筒状部１０の突条１４が有する曲面部１７が、断面視において、第２平坦部１６が属する（例えば、第２平坦部１６の表面を延長した）仮想上の平面Ｐ２よりも、第１平坦部１５に近い側に存在する（図５参照）。換言すると、曲面部１７は、その仮想上の平面Ｐ２よりも第２平坦部１６側には突出しない。例えば、曲面部１７が第２平坦部１６側に突出していると、開閉機３０のアーム３１に押されて第１平坦部１５が径方向外側に逃げるように変形するとき、突出している曲面部１７が周辺の部材（例えば、他方側に隣接する第１平坦部１５など）に接触し、第１平坦部１５の変形を妨げることになる。曲面部１７が仮想上の平面Ｐ２よりも第２平坦部１６側には突出しないことで、そのような変形の妨げが生じ難い。その結果、本実施形態に係るグロメット１は、グロメット１が有する筒状部１０に電線などを挿通させる作業の作業性に優れている。 Furthermore, according to the grommet 1 according to the present embodiment, the curved surface portion 17 of the protrusion 14 of the cylindrical portion 10 includes the second flat portion 16 in a cross-sectional view (for example, the surface of the second flat portion 16 is It exists on the side closer to the first flat part 15 than the virtual plane P2 (extended) (see FIG. 5). In other words, the curved surface portion 17 does not protrude further toward the second flat portion 16 than the virtual plane P2. For example, if the curved surface portion 17 protrudes toward the second flat portion 16 side, when the first flat portion 15 is deformed to escape radially outward by being pushed by the arm 31 of the opening/closing machine 30, the protruding curved surface portion 17 comes into contact with surrounding members (for example, the first flat part 15 adjacent to the other side) and prevents the first flat part 15 from deforming. Since the curved surface portion 17 does not protrude further toward the second flat portion 16 than the imaginary plane P2, such deformation is less likely to be hindered. As a result, the grommet 1 according to the present embodiment has excellent workability in inserting an electric wire or the like into the cylindrical portion 10 of the grommet 1.

更に、本実施形態に係るグロメット１によれば、突条１４の第１平坦部１５と筒軸Ａｘとのなす角度θ１が１０度以上８０度以下である。これにより、グロメット１の筒状部１０の本来の機能（例えば、使用時に柔軟に湾曲可能であること）を保ちながら、開閉機３０のアーム３１に接触した際の第１平坦部１５の変形（逃げ）を容易にすることができる。 Furthermore, according to the grommet 1 according to the present embodiment, the angle θ1 between the first flat portion 15 of the protrusion 14 and the cylinder axis Ax is 10 degrees or more and 80 degrees or less. As a result, while maintaining the original function of the cylindrical portion 10 of the grommet 1 (for example, being able to bend flexibly during use), the deformation of the first flat portion 15 when it comes into contact with the arm 31 of the opening/closing machine 30 ( escape) can be made easier.

更に、本実施形態に係るグロメット１によれば、突条１４の第２平坦部１６と筒軸Ａｘとのなす角度θ２が略９０度である。これにより、角度θ２が９０度よりも過度に大きい場合に比べ、第１平坦部１５の径方向外側への変形を、第２平坦部１６が出来る限り妨げないようにすることができる。更に、角度θ２が９０度よりも過度に小さい場合（いわゆるアンダーカットが生じる場合）に比べ、グロメット１を射出成形する際、金型から第２平坦部１６を分離する作業を容易にできる。 Furthermore, according to the grommet 1 according to the present embodiment, the angle θ2 between the second flat portion 16 of the protrusion 14 and the cylinder axis Ax is approximately 90 degrees. Thereby, compared to the case where the angle θ2 is excessively larger than 90 degrees, it is possible to prevent the second flat portion 16 from interfering with the radially outward deformation of the first flat portion 15 as much as possible. Furthermore, when the grommet 1 is injection molded, it is easier to separate the second flat portion 16 from the mold than when the angle θ2 is too small than 90 degrees (a so-called undercut occurs).

＜他の形態＞
なお、本発明は上記各実施形態に限定されることはなく、本発明の範囲内において種々の変形例を採用することができる。例えば、本発明は、上述した実施形態に限定されるものではなく、適宜、変形、改良、等が可能である。その他、上述した実施形態における各構成要素の材質、形状、寸法、数、配置箇所、等は本発明を達成できるものであれば任意であり、限定されない。 <Other forms>
Note that the present invention is not limited to the above embodiments, and various modifications can be adopted within the scope of the present invention. For example, the present invention is not limited to the embodiments described above, and can be modified, improved, etc. as appropriate. In addition, the material, shape, size, number, arrangement location, etc. of each component in the embodiments described above are arbitrary as long as the present invention can be achieved, and are not limited.

上記実施形態では、突条１４の曲面部１７全体が、仮想上の平面Ｐ１よりも第１平坦部１５側（一方側）には突出しておらず、且つ、仮想上の平面Ｐ２よりも第２平坦部１６側（他方側）には突出していない（図５参照）。これに対し、突条１４の曲面部１７の一部が、仮想上の平面Ｐ１よりも第１平坦部１５側（一方側）に突出していてもよいし、仮想上の平面Ｐ２よりも第２平坦部１６側（他方側）に突出していてもよい。 In the above embodiment, the entire curved surface portion 17 of the protrusion 14 does not protrude to the first flat portion 15 side (one side) from the imaginary plane P1, and the curved surface portion 17 of the protrusion 14 does not protrude from the imaginary plane P2 to the second flat portion 15 side (one side). It does not protrude toward the flat portion 16 side (the other side) (see FIG. 5). On the other hand, a part of the curved surface portion 17 of the protrusion 14 may protrude toward the first flat portion 15 side (one side) from the imaginary plane P1, or may protrude from the imaginary plane P2 toward the second flat portion 15 side (one side). It may protrude toward the flat portion 16 side (the other side).

更に、上記実施形態では、突条１４の第１平坦部１５と筒軸Ａｘとのなす角度θ１が１０度以上８０度以下であり、かつ、突条１４の第２平坦部１６と筒軸Ａｘとのなす角度θ２が略９０度である。これに対し、突条１４の第１平坦部１５と筒軸Ａｘとのなす角度θ１が１０度未満又は８０度よりも大きくてもよいし、突条１４の第２平坦部１６と筒軸Ａｘとのなす角度θ２が略９０度以外であってもよい。 Furthermore, in the embodiment described above, the angle θ1 between the first flat portion 15 of the protrusion 14 and the cylinder axis Ax is 10 degrees or more and 80 degrees or less, and the angle θ1 between the second flat portion 16 of the protrusion 14 and the cylinder axis Ax The angle θ2 between the two is approximately 90 degrees. On the other hand, the angle θ1 between the first flat portion 15 of the protrusion 14 and the cylinder axis Ax may be less than 10 degrees or greater than 80 degrees, or the angle θ1 between the first flat portion 15 of the protrusion 14 and the cylinder axis Ax may be less than 10 degrees or greater than 80 degrees. The angle θ2 between the two may be other than approximately 90 degrees.

ここで、上述した本発明に係るグロメット１の実施形態の特徴をそれぞれ以下［１］～［５］に簡潔に纏めて列記する。
［１］
弾性変形可能な筒状部を備えるグロメット（１）であって、
前記筒状部（１０）は、
均一な厚さを有する筒壁から構成され、当該筒状部（１０）の筒軸（Ａｘ）に向けて突出し且つ前記筒軸（Ａｘ）周りを周回する複数の突条（１４）を、前記筒壁によって構成し、
前記複数の前記突条（１４）の各々は、
前記筒軸（Ａｘ）を含む平面によって前記筒状部（１０）を切ったときの断面視において、第１平坦部（１５）と、第２平坦部（１６）と、前記第１平坦部（１５）と前記第２平坦部（１６）とを繋ぐ曲面部（１７）と、を有し、前記第１平坦部（１５）と前記筒軸（Ａｘ）とのなす角度である第１角度（θ１）が前記第２平坦部（１６）と前記筒軸（Ａｘ）とのなす角度である第２角度（θ２）よりも小さく、且つ、前記曲面部（１７）の前記筒軸（Ａｘ）に最も近い箇所（１８）が前記筒軸（Ａｘ）に沿って並ぶように配置される、ように構成される、
グロメット（１）。
［２］
上記［１］に記載のグロメットにおいて、
前記複数の前記突条（１４）の各々は、
前記断面視において、前記第１平坦部（１５）が属する仮想上の平面（Ｐ１）よりも前記第２平坦部（１６）に近い側に前記曲面部（１７）が位置する、ように構成される、
グロメット（１）。
［３］
上記［１］又は上記［２］に記載のグロメット（１）において、
前記複数の前記突条（１４）の各々は、
前記断面視において、前記第２平坦部（１６）が属する仮想上の平面（Ｐ２）よりも前記第１平坦部（１５）に近い側に前記曲面部（１７）が位置する、ように構成される、
グロメット（１）。
［４］
上記［１］から上記［３］の何れか一つに記載のグロメット（１）において、
前記第１角度（θ１）は、１０度以上８０度以下である、
グロメット（１）。
［５］
上記［１］から上記［４］の何れか一つに記載のグロメット（１）において、
前記第２角度（θ２）は、略９０度である、
グロメット（１）。 Here, the features of the embodiment of the grommet 1 according to the present invention described above will be briefly summarized and listed below in [1] to [5].
[1]
A grommet (1) comprising an elastically deformable cylindrical part,
The cylindrical part (10) is
A plurality of protrusions (14) are formed from a cylinder wall having a uniform thickness, protrude toward the cylinder axis (Ax) of the cylinder part (10), and orbit around the cylinder axis (Ax). Consisting of a cylindrical wall,
Each of the plurality of protrusions (14) is
In a cross-sectional view when the cylindrical portion (10) is cut along a plane including the cylindrical axis (Ax), a first flat portion (15), a second flat portion (16), and a first flat portion ( 15) and a curved surface portion (17) connecting the second flat portion (16), and a first angle (17) that is an angle between the first flat portion (15) and the cylinder axis (Ax). θ1) is smaller than the second angle (θ2) that is the angle between the second flat portion (16) and the cylinder axis (Ax), and The closest point (18) is arranged so as to be lined up along the cylinder axis (Ax),
Grommet (1).
[2]
In the grommet described in [1] above,
Each of the plurality of protrusions (14) is
In the cross-sectional view, the curved surface portion (17) is located closer to the second flat portion (16) than the virtual plane (P1) to which the first flat portion (15) belongs. Ru,
Grommet (1).
[3]
In the grommet (1) described in [1] or [2] above,
Each of the plurality of protrusions (14) is
In the cross-sectional view, the curved surface portion (17) is located closer to the first flat portion (15) than the virtual plane (P2) to which the second flat portion (16) belongs. Ru,
Grommet (1).
[4]
In the grommet (1) according to any one of [1] to [3] above,
The first angle (θ1) is 10 degrees or more and 80 degrees or less,
Grommet (1).
[5]
In the grommet (1) according to any one of [1] to [4] above,
the second angle (θ2) is approximately 90 degrees;
Grommet (1).

１グロメット
１０筒状部
１４突条
１５第１平坦部
１６第２平坦部
１７曲面部
１８頂部（曲面部の筒軸に最も近い箇所）
Ａｘ筒軸
θ１角度（第１角度）
θ２角度（第２角度） 1 Grommet 10 Cylindrical part 14 Projection 15 First flat part 16 Second flat part 17 Curved part 18 Top part (the part closest to the cylinder axis of the curved part)
Ax cylinder axis θ1 angle (first angle)
θ2 angle (second angle)

Claims

A grommet including an elastically deformable cylindrical part,
The cylindrical part is
It is composed of a cylindrical wall having a uniform thickness, and the cylindrical wall constitutes a plurality of protrusions that protrude toward the cylindrical axis of the cylindrical part and revolve around the cylindrical axis,
Each of the plurality of protrusions is
In a cross-sectional view when the cylindrical part is cut by a plane including the cylindrical axis, a first flat part, a second flat part, and a curved part connecting the first flat part and the second flat part; a first angle formed by the first flat part and the cylinder axis is smaller than a second angle formed by the second flat part and the cylinder axis, and the curved surface part The parts closest to the cylindrical axis are arranged along the cylindrical axis,
Each of the plurality of protrusions is a protrusion that goes around the cylinder axis in a plane perpendicular to the cylinder axis of the cylindrical part,
the second angle is approximately 90 degrees;
Each of the plurality of protrusions is
In the cross-sectional view, a portion of the curved surface portion is located on a side farther from the second flat portion than the hypothetical plane to which the first flat portion belongs, and/or a portion of the curved surface portion is located on a hypothetical plane to which the second flat portion belongs. A part of the curved surface part is located on a side farther from the first flat part than the plane of
grommet.

The grommet according to claim 1,
The first angle is 10 degrees or more and 80 degrees or less,
grommet.