JP7598422B2

JP7598422B2 - Grommet

Info

Publication number: JP7598422B2
Application number: JP2023129064A
Authority: JP
Inventors: 貴之鹿野; 潤弥福田
Original assignee: Inoac Corp
Current assignee: Inoac Corp
Priority date: 2019-12-26
Filing date: 2023-08-08
Publication date: 2024-12-11
Anticipated expiration: 2039-12-26
Also published as: JP7330096B2; JP2023164808A; JP2021106461A

Description

この発明は、パネルに形成した貫通孔に取り付けられるグロメットに関するものである。 This invention relates to a grommet that is attached to a through hole formed in a panel.

自動車等の車両や船舶、或いは航空機といった各種の乗物は、鋼板等により形成されたパネルにより複数の空間に仕切られており、当該パネルに形成した貫通孔を通したワイヤハーネスや各種配管により仕切られた空間に配置した機材同士を繋ぐようにしている。そして、パネルの貫通孔にワイヤハーネスなどを通す場合には、この貫通孔にゴムなどの弾性体で形成したグロメットを取り付けるようにし、貫通孔の縁部への接触による損傷を防止すると共に、貫通孔からの音や水、埃等の侵入を防止するようになっている。例えば、自動車等の車両では、車室内とエンジンルームとを隔てるダッシュパネル等の車体パネルに形成した貫通孔にグロメットを取り付け、このグロメットに挿通したワイヤハーネスによりエンジンルームに設置した電力供給源としてバッテリーと車室側に配置した各種電気機器とを繋ぐようにしている。 Various vehicles, such as automobiles, ships, and aircraft, are divided into multiple spaces by panels made of steel plates or the like, and the equipment placed in the divided spaces is connected by wire harnesses and various pipes that pass through through holes formed in the panels. When passing a wire harness or the like through the through hole of the panel, a grommet made of an elastic material such as rubber is attached to the through hole to prevent damage caused by contact with the edge of the through hole and to prevent the intrusion of sound, water, dust, and the like through the through hole. For example, in a vehicle such as an automobile, a grommet is attached to a through hole formed in a body panel such as a dash panel that separates the passenger compartment from the engine compartment, and a wire harness inserted into the grommet connects a battery installed in the engine compartment as a power supply source to various electrical devices placed on the passenger compartment side.

ここで、パネルの貫通孔に対してグロメットが不正常な状態で取り付けられていると、車両などの取付対象で発生する振動等によりグロメットが貫通孔から脱落といった不具合が起きかねない。このため、パネルにグロメットが正常に取り付けられているかを把握し得るような工夫が提案されている。例えば特許文献１のグロメットは、パネルの貫通孔を通過すると共に当該貫通孔が嵌合する周溝の縁部を形成する小径環状部に節度感用突起を設けて、パネルにグロメットを取り付ける際に、小径環状部と共に節度感用突起が貫通孔を通過する際に高まった挿入抵抗が、貫通孔に嵌まった際に急激に消失することでグロメットが正常に取り付けられたことを感触で把握できるようにしている。 Here, if the grommet is attached in an abnormal state to the through-hole of the panel, a malfunction may occur, such as the grommet falling out of the through-hole due to vibrations generated by the attachment target, such as a vehicle. For this reason, various ideas have been proposed to make it possible to know whether the grommet is attached properly to the panel. For example, the grommet in Patent Document 1 has a moderation-sensing protrusion on a small-diameter annular portion that passes through the through-hole of the panel and forms the edge of the circumferential groove into which the through-hole fits. When attaching the grommet to the panel, the insertion resistance that increases when the moderation-sensing protrusion passes through the through-hole together with the small-diameter annular portion suddenly disappears when the grommet fits into the through-hole, allowing the user to know by touch that the grommet is attached properly.

特許第６４９０４４８号公報Patent No. 6490448

しかしながら、特許文献１のように、グロメットに節度用突起を設ける構成では、当該節度用突起が貫通孔を通過する際に大きな抵抗になり、貫通孔への挿入荷重が過大になって作業負荷が過大になる。また、節度用突起を別途成形するために金型形状が複雑になりやすく、製造コストが嵩む要因ともなる。 However, in a configuration in which a moderation protrusion is provided on a grommet, as in Patent Document 1, the moderation protrusion creates a large resistance when passing through a through hole, which increases the insertion load into the through hole and the workload. In addition, since the moderation protrusion is molded separately, the shape of the mold tends to become complicated, which is also a factor in increasing manufacturing costs.

すなわち本発明は、簡単な形状で良好な節度感が得られるグロメットを提供することを目的とする。 In other words, the objective of the present invention is to provide a grommet that has a simple shape and provides a good feeling of control.

前記課題を克服し、所期の目的を達成するため、本願の請求項１に係る発明は、
弾性ゴムにより形成されてパネルの貫通孔に取り付けられるグロメットであって、
内径が漸次縮小する錐台状の基体部と、
前記基体部の小径側に設けられて両端が開口する貫通状管部と、
前記基体部の大径側に設けられて前記パネルの表面に係合して抜け止めする抜止部と、
前記基体部の大径の端部と前記抜止部との間に設けられて前記貫通孔の内周縁が係合するパネル係合溝と、
前記基体部の内側に設けられ、前記パネルの貫通孔に取り付ける際に押し込む押込部と、を備え、
前記押込部を押し込んで前記パネルの貫通孔に取り付ける際に、前記基体部の体積歪みが０．３以上となるように形成されていることを要旨とする。
このように、パネルの貫通孔に取り付ける際における基体部の体積歪みが０．３以上となるようにすることで、当該基体部が貫通孔を通り抜けた際に急激な抵抗変化を生起させることができ、パネル係合溝にパネルが嵌合した確かな感触、すなわち良好な節度感が得られる。また、パネルの貫通孔を基体部が通り抜けるだけで当該貫通孔の内周縁がパネル係合溝に係合し、グロメットがパネルに取り付けられるから、グロメット全体を簡単な形状にすることができ、パネルへの取り付け時の挿入荷重の増大を抑制することができる。 In order to overcome the above problems and achieve the intended object, the present invention according to claim 1 provides:
A grommet made of elastic rubber and attached to a through hole of a panel,
A frustum-shaped base portion whose inner diameter gradually decreases;
a through-hole tube portion provided on the small diameter side of the base portion and having both ends open;
a retaining portion provided on a large diameter side of the base portion and engaging with a surface of the panel to prevent the panel from coming off;
a panel engagement groove provided between the large diameter end of the base portion and the retaining portion, the panel engagement groove being engaged with an inner peripheral edge of the through hole;
a push-in portion provided on the inside of the base portion and pushed in when the base portion is attached to the through-hole of the panel,
The present invention is characterized in that the base portion is formed so that a volumetric strain of the base portion is 0.3 or more when the push-in portion is pushed into the through-hole of the panel and attached thereto.
In this way, by making the volumetric strain of the base portion when attached to the through hole of the panel 0.3 or more, a sudden change in resistance can be generated when the base portion passes through the through hole, and a solid feeling that the panel is fitted into the panel engagement groove, i.e., a good sense of moderation, can be obtained. Also, since the inner peripheral edge of the through hole engages with the panel engagement groove simply by passing the base portion through the through hole of the panel, and the grommet is attached to the panel, the entire grommet can be made into a simple shape, and an increase in the insertion load when attached to the panel can be suppressed.

請求項２に係る発明は、
前記押込部は、前記基体部においてパネルの貫通孔に挿通される大径側の端部から押込面までの押し込み方向の間隔が－１ｍｍ～＋５ｍｍの範囲となるように形成されていることを要旨とする。
このように、基体部における大径側の端部から押込面までの押し込み方向の間隔が－１ｍｍ～＋５ｍｍの範囲となるように押込部を形成することで、パネルの貫通孔に取り付ける際における基体部の体積歪みを０．３以上として良好な節度感を得ることができる。 The invention according to claim 2 is as follows:
The push-in portion is formed so that the distance in the pushing direction from the end of the large diameter side of the base portion that is inserted into the through hole of the panel to the push-in surface is in the range of -1 mm to +5 mm.
In this way, by forming the push-in portion so that the distance in the push-in direction from the large diameter end of the base portion to the push-in surface is in the range of -1 mm to +5 mm, the volumetric distortion of the base portion when attached to the through hole in the panel can be made to be 0.3 or more, providing a good sense of moderation.

請求項３に係る発明は、
前記基体部は、ＪＩＳＫ６２５３に基づく硬度が５０～８０の範囲となる弾性ゴムにより形成されていることを要旨とする。
このように、基体部を硬度が５０～８０の範囲となる弾性ゴムで形成することで、パネルの貫通孔に取り付ける際における基体部の体積歪みを０．３以上とすることができ、良好な節度感が得られる。 The invention according to claim 3 is
The base portion is formed of elastic rubber having a hardness in the range of 50 to 80 based on JIS K6253.
In this way, by forming the base portion from elastic rubber with a hardness in the range of 50 to 80, the volumetric distortion of the base portion when attached to the through hole of the panel can be made 0.3 or more, providing a good sense of moderation.

本発明に係るによれば、簡単な形状で良好な節度感を得ることができる。 The present invention provides a simple shape and a good sense of control.

本発明に係るグロメットを取り付けた車両の概略図である。1 is a schematic diagram of a vehicle equipped with a grommet according to the present invention; (a)は実施例に係るグロメットの側面図であり、(b)はグロメットの縦断面図であり、(c)はグロメットの要部拡大断面図である。1A is a side view of a grommet according to an embodiment of the present invention, FIG. 1B is a vertical cross-sectional view of the grommet, and FIG. 1C is an enlarged cross-sectional view of a main portion of the grommet. (a)は実施例に係る接続管の側面図であり、(b)はグロメットに接続管を取り付けた状態での縦断面図である。FIG. 2A is a side view of a connecting pipe according to the embodiment, and FIG. 2B is a vertical cross-sectional view of the connecting pipe attached to a grommet. パネルに対するグロメットの取付工程を示す説明図であって、(a)はパネルの貫通孔の縁部に基体部の外周面が接触した状態を示し、(b)はグロメットを押し込んで貫通孔の開口縁に基体部の環状端部が接した状態を示し、(c)はパネルにグロメットが取り付けられた状態を示している。FIG. 11 is an explanatory diagram showing the process of attaching a grommet to a panel, in which (a) shows the state in which the outer surface of the base part is in contact with the edge of the through hole in the panel, (b) shows the state in which the grommet is pushed in so that the annular end part of the base part is in contact with the opening edge of the through hole, and (c) shows the state in which the grommet is attached to the panel. 接続管を省略した状態でグロメットとパネルの関係を示す説明図であって、パネルの貫通孔の縁部に基体部の外周面が接触したグロメットを押込力Ｆで押した状態を示している。This is an explanatory diagram showing the relationship between the grommet and the panel with the connecting pipe omitted, and shows the state in which the grommet, with the outer surface of the base part in contact with the edge of the through hole in the panel, is pushed with a pushing force F.

次に、本発明にグロメットにつき、添付図面を参照して以下に説明する。本実施形態では、水素と酸素との化学反応により発電して電動モータを駆動する燃料電池自動車の車両のパネルに設けられた貫通孔に取り付けられるグロメットを例示して説明する。 Next, the grommet of the present invention will be described below with reference to the attached drawings. In this embodiment, a grommet that is attached to a through hole provided in a panel of a fuel cell vehicle that generates electricity through a chemical reaction between hydrogen and oxygen to drive an electric motor will be described as an example.

（実施例）
このグロメット１０は、図１に示すように、ＥＰＤＭゴム等の弾性変形可能な弾性ゴムにより一体成形されており、自動車ＭＴの車室ＨＲの前方に設けられた電動モータが設置された車両前方のモータルームＭＲと燃料電池ＢＡＴの収容室ＨＲ内とを隔てるパネル５０の貫通孔５０ａに取り付けて用いられる。またこのグロメット１０には、燃料電池に対するガス排出用のホース(図示せず)を中継接続する接続管３０が取り付けられており、モータルームＭＲ側のホースと収容室ＨＲ側のホースの夫々を接続管３０に接続して中継することで、発熱時に燃料電池ＢＡＴで発生するガスを収納室ＨＲ外に放出し得るようにしている。 (Example)
1, this grommet 10 is integrally molded from an elastically deformable elastic rubber such as EPDM rubber, and is used by attaching it to a through hole 50a in a panel 50 that separates a motor room MR at the front of the vehicle in which an electric motor provided in front of the passenger compartment HR of an automobile MT is installed, from the interior of the accommodation room HR of the fuel cell BAT. A connecting pipe 30 that relays a hose (not shown) for discharging gas from the fuel cell is attached to this grommet 10, and by connecting and relaying the hose on the motor room MR side and the hose on the accommodation room HR side to the connecting pipe 30, gas generated by the fuel cell BAT when it generates heat can be discharged outside the accommodation room HR.

このグロメット１０は、図２に示すように、パネル５０の貫通孔５０ａに弾性変形を伴って通過可能に形成された基体部１２と、パネル５０の貫通孔５０ａより大径に形成されて当該貫通孔５０ａを通過不能な抜止部１４と、当該基体部１２および抜止部１４の間に設けられてパネル５０の貫通孔５０ａの内周縁が係合可能な溝状のパネル係合溝１６と、当該基体部１２に対してパネル係合溝１６と反対側に位置するよう設けられて両端が開口する貫通孔１８ａが形成された貫通状管部１８と、を備えている。具体的に、基体部１２は、内径が漸次拡大する円錐台状に傾斜するよう形成されて、大径側の端部にパネル係合溝１６を介して抜止部１４が連なるように設けられている。そして、基体部１２の小径側の端部に貫通状管部１８が形成されて、当該貫通状管部１８の貫通孔１８ａが基体部１２の内側および外側で開口するようになっている。このように、グロメット１０は、基体部１２と貫通状管部１８により漏斗状をなしている。なお、以下において、グロメット１０の貫通状管部１８の形成側を前側とし、基体部１２の大径側の開口側を後側として説明する場合がある。 2, the grommet 10 includes a base portion 12 formed to be able to pass through the through hole 50a of the panel 50 with elastic deformation, a retaining portion 14 formed with a diameter larger than the through hole 50a of the panel 50 and unable to pass through the through hole 50a, a groove-shaped panel engagement groove 16 provided between the base portion 12 and the retaining portion 14 and capable of engaging with the inner peripheral edge of the through hole 50a of the panel 50, and a through-hole tubular portion 18 provided on the opposite side of the base portion 12 from the panel engagement groove 16 and having a through hole 18a with both ends open. Specifically, the base portion 12 is formed to be inclined in a truncated cone shape with an inner diameter gradually expanding, and the retaining portion 14 is provided to be connected to the end of the large diameter side via the panel engagement groove 16. A through-hole 18 is formed at the small-diameter end of the base 12, and the through-hole 18a of the through-hole 18 opens on the inside and outside of the base 12. In this way, the grommet 10 is funnel-shaped with the base 12 and the through-hole 18. In the following description, the side of the grommet 10 where the through-hole 18 is formed may be referred to as the front side, and the opening side of the large-diameter side of the base 12 may be referred to as the rear side.

ここで、基体部１２の大径側の端部(以下、環状端部１２ｂという場合がある)の外周縁は、パネル５０の貫通孔５０ａより大径になるよう形成されると共に、パネル係合溝１６の外周縁は、この環状端部１２ｂより小径でかつ貫通孔５０ａより僅かに大径になるよう形成されている。すなわち、図４に示すように、パネル５０の一方側(例えばモータルームＭＲ側)から基体部１２の小径側(貫通状管部１８)を貫通孔５０ａに臨ませて、基体部１２の傾斜した外周面１２ａを貫通孔５０ａの縁部に接した状態で押し込むことにより、基体部１２を含むグロメット１０の全体的な弾性変形を伴って基体部１２が貫通孔５０ａを通り抜けるようになっている。そして、基体部１２が貫通孔５０ａを通り抜けることで、パネル係合溝１６に貫通孔５０ａの内周縁が係合すると共に、基体部１２の環状端部１２ｂと抜止部１４との間にパネル５０が挟まれるようにしてパネル５０にグロメット１０が取り付けられるようになっている。このように、パネル５０の貫通孔５０ａに対してグロメット１０を装着することで、パネル５０の貫通孔５０ａのエッジからホースを保護すると共に、当該貫通孔５０ａを介して水や埃等が浸入するのを防止している。 Here, the outer periphery of the large-diameter end of the base portion 12 (hereinafter sometimes referred to as the annular end portion 12b) is formed to have a larger diameter than the through-hole 50a of the panel 50, and the outer periphery of the panel engagement groove 16 is formed to have a smaller diameter than the annular end portion 12b and a slightly larger diameter than the through-hole 50a. That is, as shown in Fig. 4, the small-diameter side (through-shaped tube portion 18) of the base portion 12 is brought into contact with the edge of the through-hole 50a from one side of the panel 50 (for example, the motor room MR side), and the inclined outer periphery 12a of the base portion 12 is pushed in while in contact with the edge of the through-hole 50a, so that the base portion 12 passes through the through-hole 50a with the overall elastic deformation of the grommet 10 including the base portion 12. As the base portion 12 passes through the through hole 50a, the inner peripheral edge of the through hole 50a engages with the panel engagement groove 16, and the grommet 10 is attached to the panel 50 such that the panel 50 is sandwiched between the annular end portion 12b of the base portion 12 and the retaining portion 14. In this way, by attaching the grommet 10 to the through hole 50a of the panel 50, the hose is protected from the edge of the through hole 50a of the panel 50 and water, dust, etc. are prevented from entering through the through hole 50a.

また、図２(b)に示すように、グロメット１０には、基体部１２の内側からパネル５０の貫通孔５０ａに押し込み可能にする押込部２０が設けられている。この押込部２０は、基体部１２の内側において当該基体部１２の小径側の端部に、貫通状管部１８の貫通孔１８ａに連通する円筒状に設けられている。すなわち、貫通状管部１８および押込部２０により連続した貫通孔１８ａを形成している。ここで、押込部２０の後端面をなす押込面２０ａから基体部１２までの離間間隔は、押込部２０の全周に亘って一定になるよう形成されており、グロメット１０をパネル５０に取り付ける際に、貫通状管部１８を貫通孔５０ａに臨ませた状態で押込部２０の押込面２０ａを前方に向けて押した際に、貫通孔５０ａの縁部に宛がった基体部１２に対して概ね均等に力を作用させて、基体部１２の全体を弾性変形させ得るようにしてある。ここで、基体部１２は、図２(c)に示すように、押込部２０との連設位置(押込部２０の基端部)に肉厚部１２ｃが設けられている。すなわち、基体部１２における押込部２０との連設位置に肉厚部１２ｃを設けることで、基体部１２の内側への弾性変形を抑制すると共に、弾性変形した基体部１２が弾発的に原形に復帰し易くしてある。 2(b), the grommet 10 is provided with a push-in portion 20 that enables the grommet 10 to be pushed into the through-hole 50a of the panel 50 from the inside of the base portion 12. This push-in portion 20 is provided on the inside of the base portion 12 at the small diameter end of the base portion 12, in a cylindrical shape that communicates with the through-hole 18a of the penetrating tube portion 18. In other words, the penetrating tube portion 18 and the push-in portion 20 form a continuous through-hole 18a. Here, the distance between the pushing surface 20a forming the rear end surface of the pushing portion 20 and the base portion 12 is formed to be constant over the entire circumference of the pushing portion 20, so that when the grommet 10 is attached to the panel 50, the pushing surface 20a of the pushing portion 20 is pushed forward with the penetrating tube portion 18 facing the through hole 50a, a generally uniform force is applied to the base portion 12 that faces the edge of the through hole 50a, and the entire base portion 12 is elastically deformed. Here, as shown in FIG. 2(c), the base portion 12 is provided with a thick portion 12c at the connecting position with the pushing portion 20 (the base end of the pushing portion 20). That is, by providing the thick portion 12c at the connecting position with the pushing portion 20 in the base portion 12, the inward elastic deformation of the base portion 12 is suppressed, and the elastically deformed base portion 12 is easily restored to its original shape.

また、図３に示すように、グロメット１０に取り付けられる接続管３０は、長手方向に沿って貫通孔３２ａが形成された管体３２と、当該管体３２の両端に設けられてホースの端部に差し込まれる係止爪部３８とを備えている。この係止爪部３８は、当該係止爪部３８を設けた管体３２の端部から他方側の端部に向けて、管体３２の外周面から離れるように傾斜したテーパ状に形成されており、当該係止爪部３８により接続したホースが抜け止めされるようになっている。なお、この実施例の管体３２は、グロメット１０(貫通状管部１８)の貫通孔１８ａに後方から挿通される第１管部３４と、当該グロメット１０の外側において第１管部３４から屈曲するように延在する第２管部３６とから形成されているが、当該管体３２の形状は任意であり、例えば管体３２の全体を直線状に形成してもよい。ここで、貫通状管部１８の貫通孔１８ａに第１管部３４を挿通した際に、当該第１管体３４に設けた係止爪部３８が貫通状管部１８の前端面１８ｂに係止するようになっており、これにより接続管３０のグロメット１０からの離脱を防止している。 3, the connecting pipe 30 attached to the grommet 10 includes a pipe body 32 with a through hole 32a formed along the longitudinal direction, and a locking claw portion 38 provided at both ends of the pipe body 32 and inserted into the end of the hose. The locking claw portion 38 is formed in a tapered shape that is inclined away from the outer circumferential surface of the pipe body 32 from the end of the pipe body 32 where the locking claw portion 38 is provided to the other end, so that the connected hose is prevented from coming off by the locking claw portion 38. Note that the pipe body 32 in this embodiment is formed of a first pipe portion 34 that is inserted from the rear into the through hole 18a of the grommet 10 (through pipe portion 18) and a second pipe portion 36 that extends from the first pipe portion 34 so as to bend outside the grommet 10, but the shape of the pipe body 32 is arbitrary, and for example, the entire pipe body 32 may be formed in a straight line. When the first tube 34 is inserted into the through hole 18a of the through tube 18, the locking claw 38 on the first tube 34 locks onto the front end surface 18b of the through tube 18, thereby preventing the connecting tube 30 from coming off the grommet 10.

また、第１管部３４には、第１管部３４の径方向外方に延出するように押圧板４０が設けられている。この押圧板４０は、当該第１管部３４の係止爪部３８をグロメット１０の貫通状管部１８の貫通孔１８ａに挿通して係止した状態で、当該グロメット１０の押込部２０の押込面２０ａに当接するようになっている。ここで、第１管部３４の係止爪部３８から押圧板４０までの間隔は、貫通状管部１８の前端面１８ｂから押込部２０の押込面２０ａまでの間隔とほぼ一致するよう形成されており、貫通状管部１８の前端面１８ｂに第１管部３４の係止爪部３８が係止すると共に押込部２０の押込面２０ａに押圧板４０が当接することにより、接続管３０がグロメット１０に対して所定位置に安定して保持されるようになっている。 The first tube section 34 is provided with a pressure plate 40 extending radially outward from the first tube section 34. The pressure plate 40 is adapted to abut against the push-in surface 20a of the push-in section 20 of the grommet 10 when the locking claw section 38 of the first tube section 34 is inserted and locked into the through hole 18a of the through-hole 18a of the through-hole 18 of the grommet 10. Here, the distance from the locking claw section 38 of the first tube section 34 to the pressure plate 40 is formed to be approximately equal to the distance from the front end surface 18b of the through-hole 18 to the push-in surface 20a of the push-in section 20, and the locking claw section 38 of the first tube section 34 is locked to the front end surface 18b of the through-hole 18 and the pressure plate 40 abuts against the push-in surface 20a of the push-in section 20, so that the connection tube 30 is stably held in a predetermined position relative to the grommet 10.

また、第１管部３４には、押圧板４０よりも第１管部３４の端部から離れた位置に保護板４２を設けてある。この保護板４２は、押圧板４０よりも大径に形成されて、基体部１２の後方開口の外側において当該後方開口を塞ぐように覆っている。すなわち、保護板４２により基体部１２の内側への異物侵入を防止し、グロメット１０の損傷を防ぐようにしてある。 The first tube section 34 is provided with a protective plate 42 at a position farther from the end of the first tube section 34 than the pressure plate 40. This protective plate 42 is formed with a larger diameter than the pressure plate 40, and covers the rear opening of the base section 12 from the outside so as to close the rear opening. In other words, the protective plate 42 prevents foreign matter from entering the inside of the base section 12 and prevents damage to the grommet 10.

次に、グロメット１０の構成についてパネル５０への取り付け時の作用とより詳細に説明する。なお、接続管３０は、パネル５０に対するグロメット１０の取り付け前および取り付け後の何れのタイミングでグロメット１０に取り付けるようにしてもよいが、ここでは接続管３０を取り付けた状態でグロメット１０をパネル５０に取り付けるものとする。図４(a)に示すように、グロメット１０をパネル５０に取り付ける際に、貫通状管部１８を貫通孔５０ａに臨ませた状態で押込部２０の押込面２０ａを前方に向けて押して、基体部１２をパネル５０の貫通孔５０ａに押し込む。ここで、接続管３０をグロメット１０に取り付けた状態では、接続管３０を把持して前方に押し込むことで、当該接続管３０の押圧板４０により押込部２０の押込面２０ａを前方に向けて押すことができる。 Next, the configuration of the grommet 10 and its action when attached to the panel 50 will be described in more detail. The connection pipe 30 may be attached to the grommet 10 either before or after the grommet 10 is attached to the panel 50. Here, the grommet 10 is attached to the panel 50 with the connection pipe 30 attached. As shown in FIG. 4(a), when attaching the grommet 10 to the panel 50, the push-in surface 20a of the push-in portion 20 is pushed forward with the penetrating pipe portion 18 facing the through hole 50a, and the base portion 12 is pushed into the through hole 50a of the panel 50. Here, when the connection pipe 30 is attached to the grommet 10, the connection pipe 30 can be grasped and pushed forward to push the push-in surface 20a of the push-in portion 20 forward by the push plate 40 of the connection pipe 30.

基体部１２をパネル５０の貫通孔５０ａに押し込んでいる間は、貫通孔５０ａの縁部に摺動しながら基体部１２が内側に向けて弾性変形する。そして、図４(b)に示すように、基体部１２の弾性変形は、基体部１２の環状端部１２ｂが貫通孔５０ａの開口縁に臨む状態で最大になる。そして、基体部１２の環状端部１２ｂが貫通孔５０ａを通り抜けることで、基体部１２が弾発的に原形に復帰し、パネル係合溝１６にパネル５０が係合する(図４(c)参照))。 While the base portion 12 is being pressed into the through hole 50a of the panel 50, the base portion 12 elastically deforms inward as it slides against the edge of the through hole 50a. Then, as shown in FIG. 4(b), the elastic deformation of the base portion 12 is at its maximum when the annular end portion 12b of the base portion 12 faces the opening edge of the through hole 50a. Then, as the annular end portion 12b of the base portion 12 passes through the through hole 50a, the base portion 12 elastically returns to its original shape, and the panel 50 engages with the panel engagement groove 16 (see FIG. 4(c)).

ここで、押込部２０は、基体部１２の傾斜した外周面１２ａを貫通孔５０ａの縁部に接した状態で前方に向けて押した際に、基体部１２を外側に押す力を作用するよう形成されて、基体部１２の体積歪みを増加させるようにしてある。ここで、体積歪みとは、体積変形に関わる歪みであり、基体部１２の体積変化をもとの基体部１２の体積で除したものである。すなわち、体積歪みをε、変形前の基体部１２の体積をＶ_１、変形後の基体部１２の体積をＶ_２とした場合に、ε＝(Ｖ_２－Ｖ_１)／Ｖ_１により表される。この体積歪みは、ＣＡＥ解析によって求めるようにしてもよく、また実際に試験品を作製して実測により求めるようにしてもよい。この実施形態ではＣＡＥ解析によって体積歪みを求めている。すなわち、図５に示すように、押込部２０の押込面２０ａを前方に向けて所定の押込力Ｆで押した際に、基体部１２がパネルの貫通孔５０ａの縁部に接触することで、基体部１２を外側に押すように力Ｆ１が作用し、基体部１２の内面側が圧縮するように変形すると共に外面側が伸張するように変形して(図４(b)参照)、基体部１２とパネルの貫通孔５０ａの縁部との接触部に応力が集中して基体部１２の体積歪みが増加する。 Here, the pushing part 20 is formed so as to exert a force pushing the base part 12 outward when the inclined outer peripheral surface 12a of the base part 12 is pushed forward while in contact with the edge of the through hole 50a, thereby increasing the volumetric strain of the base part 12. Here, the volumetric strain is a strain related to volumetric deformation, and is obtained by dividing the volume change of the base part 12 by the original volume of the base part 12. That is, when the volumetric strain is ε, the volume of the base part 12 before deformation is V ₁ , and the volume of the base part 12 after deformation is V ₂ , it is expressed by ε=(V ₂ -V ₁ )/V _1. This volumetric strain may be obtained by CAE analysis, or may be obtained by actually manufacturing a test sample and measuring it. In this embodiment, the volumetric strain is obtained by CAE analysis. That is, as shown in Figure 5, when the pressing surface 20a of the pressing portion 20 is pressed forward with a predetermined pressing force F, the base portion 12 comes into contact with the edge of the through hole 50a in the panel, and a force F1 acts to push the base portion 12 outward, causing the inner surface side of the base portion 12 to deform in a compressed manner and the outer surface side to deform in an expanded manner (see Figure 4(b)). As a result, stress is concentrated at the contact point between the base portion 12 and the edge of the through hole 50a in the panel, and the volumetric distortion of the base portion 12 increases.

ここで、グロメット１０は、パネル５０の貫通孔５０ａに取り付ける際に、基体部１２の体積歪みが０．３以上となるように形成される。基体部１２の体積歪みが０．３以上となるようにすることで、基体部１２の環状端部１２ｂが貫通孔５０ａを通り抜けて基体部１２が弾発的に原形に復帰した際にグロメット１０の挿入抵抗が急激に消失し、パネル係合溝１６にパネル５０が間違いなく嵌合したという触覚(節度感)を得ることができる。また、パネル係合溝１６の外周縁を貫通孔５０ａより僅かに大径になるよう形成してあるから、基体部１２が弾発的に原形に復帰した際にパネル５０の貫通孔５０ａの開口縁がパネル係合溝１６に勢いよく接触し、挿入抵抗が急激に消失する触覚だけでなく接触音などの聴覚を通じてパネル係合溝１６にパネル５０が間違いなく嵌合したという節度感を得ることができる。 Here, the grommet 10 is formed so that the volumetric strain of the base portion 12 is 0.3 or more when it is attached to the through hole 50a of the panel 50. By making the volumetric strain of the base portion 12 0.3 or more, when the annular end portion 12b of the base portion 12 passes through the through hole 50a and the base portion 12 elastically returns to its original shape, the insertion resistance of the grommet 10 suddenly disappears, and a tactile sense (feeling of moderation) that the panel 50 is definitely fitted into the panel engagement groove 16 can be obtained. In addition, since the outer periphery of the panel engagement groove 16 is formed to be slightly larger in diameter than the through hole 50a, when the base portion 12 elastically returns to its original shape, the opening edge of the through hole 50a of the panel 50 comes into forceful contact with the panel engagement groove 16, and not only the tactile sense of the sudden disappearance of the insertion resistance, but also the auditory sense of the contact sound, etc., can be obtained that the panel 50 is definitely fitted into the panel engagement groove 16.

また、基体部１２の体積歪みは０．３３以上となるようにすることがより好ましく、体積歪みが０．３６以上となることがより好ましい。基体部１２の体積歪みこのような範囲にすることで、節度感をより際立たせることができる。特に、体積歪みを０．３６以上とした場合には、際立った節度感が得られることから、取付状態の目視による確認が不可能であったり困難な場所にグロメット１０を取り付ける場合に好適である。また、基体部１２の体積歪みが増大すると、基体部１２の弾性変形に伴う挿入抵抗が過大になり、作業性を損なうことに繋がる。このため、グロメット１０をパネル５０に取り付ける際の基体部１２の体積歪みは０．５以下であることが好ましく、０．４８以下であることがより好ましい。 Moreover, it is more preferable that the volumetric strain of the base portion 12 is 0.33 or more, and more preferably that the volumetric strain is 0.36 or more. By setting the volumetric strain of the base portion 12 in such a range, the sense of moderation can be made more prominent. In particular, when the volumetric strain is 0.36 or more, a prominent sense of moderation can be obtained, which is suitable when the grommet 10 is attached to a location where visual confirmation of the attachment state is impossible or difficult. Furthermore, if the volumetric strain of the base portion 12 increases, the insertion resistance associated with the elastic deformation of the base portion 12 becomes excessive, which leads to a loss of workability. For this reason, it is preferable that the volumetric strain of the base portion 12 when attaching the grommet 10 to the panel 50 is 0.5 or less, and more preferably 0.48 or less.

具体的に、図２(c)に示すように、押込部２０は、パネル５０に対するグロメット１０の取付姿勢を基準として、基体部１２の環状端部１２ｂの突出端から押込面２０ａまでの貫通孔５０ａの開口方向(押し込み方向)の間隔Ｌが－１ｍｍ～＋５ｍｍとなるように形成される。なお、押込部２０の押込面２０ａが環状端部１２ｂの突出端より前側に位置する状態を(－)で示し、環状端部１２ｂの突出端より後側に位置する状態を(＋)で示している。押込部２０の押込面２０ａが基体部１２の環状端部１２ｂに対して上記範囲に位置することで、基体部１２をパネル５０の貫通孔５０ａに押し込む過程で基体部１２の環状端部１２ｂが貫通孔５０ａの縁部の内側に接触し、基体部１２の弾性変形が最大になった状態(図の状態)で基体部１２の体積歪みを０．３～０．５とすることができる。 2(c), the push-in portion 20 is formed so that the distance L in the opening direction (pushing direction) of the through hole 50a from the protruding end of the annular end 12b of the base portion 12 to the push-in surface 20a is -1 mm to +5 mm, based on the mounting attitude of the grommet 10 relative to the panel 50. Note that the state in which the push-in surface 20a of the push-in portion 20 is located forward of the protruding end of the annular end 12b is indicated by (-), and the state in which it is located rearward of the protruding end of the annular end 12b is indicated by (+). By positioning the pushing surface 20a of the pushing portion 20 within the above range relative to the annular end 12b of the base portion 12, the annular end 12b of the base portion 12 comes into contact with the inside edge of the through hole 50a in the process of pushing the base portion 12 into the through hole 50a of the panel 50, and the volumetric strain of the base portion 12 can be set to 0.3 to 0.5 when the elastic deformation of the base portion 12 is at its maximum (state in the figure).

更に、グロメット１０は、ＪＩＳＫ６２５３に基づいてデュロメータ硬さ試験機(タイプＡ)で測定した硬度が５０～８０の範囲となる弾性ゴムにより形成することが望ましい。また、グロメット１０の押込部２０の厚みＴは、パネル５０の貫通孔５０ａの内径Ｄ(直径)に対して、Ｔ／Ｄ×１００≧１０(％)の厚みとなるように形成することが望ましい。すなわち、押込部２０の厚みＴが貫通孔５０ａの内径Ｄに対して薄すぎる場合には、押込部２０の押込面２０ａを押し込んだ際に、当該押込部２０が座屈しやすくなり、押込部２０の押込面２０ａのパネル面５２に対する位置を前述した範囲に保持できなくなる可能性がある。 Furthermore, it is preferable that the grommet 10 is formed from an elastic rubber having a hardness in the range of 50 to 80 as measured with a durometer hardness tester (Type A) based on JIS K6253. It is also preferable that the thickness T of the pushing portion 20 of the grommet 10 is formed so that the thickness T is T/D×100≧10(%) with respect to the inner diameter D (diameter) of the through hole 50a of the panel 50. In other words, if the thickness T of the pushing portion 20 is too thin compared to the inner diameter D of the through hole 50a, the pushing portion 20 is likely to buckle when the pushing surface 20a of the pushing portion 20 is pushed in, and it may not be possible to maintain the position of the pushing surface 20a of the pushing portion 20 relative to the panel surface 52 within the aforementioned range.

すなわち、押込部２０の押込面２０ａのパネル面５２に対する位置関係や、弾性ゴムの硬度、押込部２０の厚みを、上記の範囲となるようにグロメット１０を形成することで、基体部１２の体積歪みを０．３～０．５となるようにすることができ、グロメット１０のパネル５０の貫通孔５０ａに対する挿入荷重を過大に高めることなく、パネル５０への取り付け時には良好な節度感を得ることができる。また、このグロメット１０をパネル５０に取り付ける際には、パネル５０の貫通孔５０ａを基体部が通過するだけでパネル係合溝１６に貫通孔５０ａの内周縁が係合する。すなわち、グロメット１０の取り付け時の節度感を高めるために突起などを形成する必要が無く、グロメット１０全体を簡単な形状にすることができ、パネル５０への取り付け時の挿入荷重の増大を抑制することができる。また、グロメット１０を簡単な形状にすることができるから、グロメット１０を成形するための金型形状を単純にでき、製造コストを安価に抑制することができる利点がある。 That is, by forming the grommet 10 so that the positional relationship of the pushing surface 20a of the pushing portion 20 to the panel surface 52, the hardness of the elastic rubber, and the thickness of the pushing portion 20 are within the above ranges, the volumetric distortion of the base portion 12 can be set to 0.3 to 0.5, and a good sense of moderation can be obtained when attaching the grommet 10 to the panel 50 without excessively increasing the insertion load of the grommet 10 into the through hole 50a of the panel 50. Furthermore, when attaching this grommet 10 to the panel 50, the inner periphery of the through hole 50a engages with the panel engagement groove 16 simply by passing the base portion through the through hole 50a of the panel 50. That is, there is no need to form protrusions or the like to increase the sense of moderation when attaching the grommet 10, and the entire grommet 10 can be made into a simple shape, and an increase in the insertion load when attaching to the panel 50 can be suppressed. In addition, because the grommet 10 can be made into a simple shape, the shape of the mold for molding the grommet 10 can be simplified, which has the advantage of keeping manufacturing costs low.

(試験例)
ここで、試験体１～試験体５とするグロメット１０を作成し、パネル５０に形成した内径２５ｍｍとした貫通孔５０ａにグロメット１０を取り付ける取付試験を行った。その取付試験の結果を表１に示す。この試験体１～試験体５のグロメット１０は、ＪＩＳＫ６２５３に基づいてデュロメータ硬さ試験機(タイプＡ)で測定した硬度が６０のＥＰＤＭゴムを用いて基体部１２の厚み：１．４ｍｍ、基体部１２の環状端部１２ｂの外周径：１７．８ｍｍ、パネル係合溝１６の外周径２．６ｍｍ、押込部２０の厚み：２．５ｍｍとなるように形成した。また、基体部１２をパネル５０の貫通孔５０ａに押し込む過程で基体部１２の環状端部１２ｂが貫通孔５０ａの開口縁に臨んだ状態で、パネル面５２に対する押込部２０の押込面２０ａは、試験体１では＋４．５ｍｍに位置し、試験体２では＋０．２ｍｍに位置し、試験体３では－０．５ｍｍに位置し、試験体４では－２．５ｍｍに位置し、試験体５では－４．５ｍｍに位置するように、各試験体に押込部２０を形成してある。なお、パネル５０の貫通孔５０ａに対するグロメット１０の挿入速度は、１０ｍｍ／ｍｉｎとした。 (Test Example)
Here, grommets 10 were prepared as specimens 1 to 5, and an attachment test was conducted in which the grommets 10 were attached to through holes 50a having an inner diameter of 25 mm formed in a panel 50. The results of the attachment test are shown in Table 1. The grommets 10 of specimens 1 to 5 were formed using EPDM rubber having a hardness of 60 as measured with a durometer hardness tester (type A) based on JIS K6253, so that the thickness of the base portion 12 was 1.4 mm, the outer circumferential diameter of the annular end portion 12b of the base portion 12 was 17.8 mm, the outer circumferential diameter of the panel engagement groove 16 was 2.6 mm, and the thickness of the push-in portion 20 was 2.5 mm. Further, the push-in portion 20 is formed on each test body so that, in the process of pushing the base portion 12 into the through hole 50a of the panel 50, the push-in surface 20a of the push-in portion 20 relative to the panel surface 52 is located at +4.5 mm in test body 1, +0.2 mm in test body 2, -0.5 mm in test body 3, -2.5 mm in test body 4, and -4.5 mm in test body 5. The insertion speed of the grommet 10 into the through hole 50a of the panel 50 was 10 mm/min.

表１に示すように、試験体１～３に係るグロメット１０は、基体部１２の体積歪みがそれぞれ４６、３６、３２となり、基体部１２の環状端部１２ｂが貫通孔５０ａを通り抜けてグロメット１０がパネル５０に取り付けられた際に、その挿入抵抗が急激に消失してパネル係合溝１６にパネル５０が嵌合したことを触覚および聴覚で把握できる良好な節度感を得ることができた。一方で、試験体４～５に係るグロメット１０は、基体部１２の体積歪みがそれぞれ２６、２４となり、基体部１２の環状端部１２ｂが貫通孔５０ａを通り抜けてグロメット１０がパネル５０に取り付けられた際の挿入抵抗の変化に乏しく、充分な節度感を得ることができなかった。すなわち、この官能試験の結果からも、基体部１２の体積歪みを０．３～０．５の範囲になるようにグロメット１０を形成することで、グロメット１０をパネル５０に取り付けた際に良好な節度感が得られることが分かる。 As shown in Table 1, the volumetric distortion of the base portion 12 of the grommets 10 of test specimens 1 to 3 was 46, 36, and 32, respectively, and when the annular end portion 12b of the base portion 12 passed through the through hole 50a and the grommet 10 was attached to the panel 50, the insertion resistance disappeared suddenly, and a good sense of moderation was obtained, allowing the user to grasp by touch and hearing that the panel 50 was engaged in the panel engagement groove 16. On the other hand, the volumetric distortion of the base portion 12 of the grommets 10 of test specimens 4 to 5 was 26 and 24, respectively, and when the annular end portion 12b of the base portion 12 passed through the through hole 50a and the grommet 10 was attached to the panel 50, there was little change in the insertion resistance, and a sufficient sense of moderation could not be obtained. In other words, the results of this sensory test show that by forming the grommet 10 so that the volumetric distortion of the base portion 12 is in the range of 0.3 to 0.5, a good sense of moderation can be obtained when the grommet 10 is attached to the panel 50.

(変更例)
前述した実施例の構成に限定されず、例えば以下のように変更することができる。
(１) 押込部２０を円筒状に形成するようにしたが、円筒状である必要はなく、例えば角筒状に形成するようにしてもよい。
(２) 押込部２０は、壁面が連続した円筒状である必要はなく、押込部２０を複数形成し、複数の押込部２０で例えば円筒状をなすようにしてもよい。また、分割した複数の押込部２０の間に隙間を形成するようにしてもよい。押込部２０の壁面を連続した形状に形成した場合には、当該押込部２０の押込面２０ａを押し込んだ際に、基体部１２に対して均等になるように力を作用させることができる利点がある。
(３) 実施例では、グロメット１０に接続管３０を取り付けるようにしたが、接続管３０を省略することも可能である。すなわち、グロメット１０の押込部２０の押込面２０ａを作業者の手指や工具等で押し込むようにしてもよい。また貫通孔１８ａにワイヤハーネスを挿通するグロメット１０に適用し得ることは当然である。また、グロメット１０は、収容室ＨＲを隔てるパネル５０に取り付ける構成に限られず、空間を仕切るように設けた各種パネルに取り付けることができるものである。 (Example of change)
The configuration of the embodiment is not limited to the above, and can be modified as follows, for example.
(1) Although the pushing portion 20 is formed in a cylindrical shape, it does not have to be cylindrical and may be formed in, for example, a square tube shape.
(2) The pushing portion 20 does not need to have a continuous cylindrical wall surface, and a plurality of pushing portions 20 may be formed, for example, so that the plurality of pushing portions 20 form a cylindrical shape. Also, gaps may be formed between the divided plurality of pushing portions 20. When the wall surface of the pushing portion 20 is formed in a continuous shape, there is an advantage that a force can be applied uniformly to the base portion 12 when the pushing surface 20a of the pushing portion 20 is pushed in.
(3) In the embodiment, the connecting pipe 30 is attached to the grommet 10, but the connecting pipe 30 may be omitted. That is, the pushing surface 20a of the pushing portion 20 of the grommet 10 may be pushed in by the worker's finger, a tool, or the like. It is also possible to apply this to the grommet 10 in which the wire harness is inserted into the through hole 18a. Furthermore, the grommet 10 is not limited to a configuration in which it is attached to the panel 50 that separates the accommodation chamber HR, but can be attached to various panels that are provided to separate a space.

１０グロメット，１２基体部，１４抜止部，１６パネル係合溝
１８貫通状管部，２０押込部 10 Grommet, 12 Base portion, 14 Stop portion, 16 Panel engagement groove, 18 Through-hole tube portion, 20 Push-in portion

Claims

A grommet made of elastic rubber and attached to a through hole of a panel,
A frustum-shaped base portion whose inner diameter gradually decreases;
a through-hole tube portion provided on the small diameter side of the base portion and having both ends open;
a retaining portion provided on a large diameter side of the base portion and engaging with a surface of the panel to prevent the panel from coming off;
a panel engagement groove provided between the large diameter end of the base portion and the retaining portion, the panel engagement groove being engaged with an inner peripheral edge of the through hole;
a push-in portion provided on the inside of the base portion and pushed in when the base portion is attached to the through-hole of the panel,
the pressing portion is formed such that a distance in a pressing direction from an end portion on a large diameter side of the base portion that is inserted into the through hole of the panel to a pressing surface is within a range of −1 mm to +5 mm ,
The base portion is formed of an elastic rubber having a hardness in the range of 50 to 80 based on JIS K6253,
The thickness (T) of the pressed-in portion is set to be T/D×100≧10(%) with respect to the inner diameter (D) of the through hole of the panel.
A grommet characterized by: