【０００１】
【発明の属する技術分野】
本発明は、発泡材が充填される閉断面の部材を有する車体構造、及び、閉断面の部材を有する車体における発泡材の施工方法に関する。
【０００２】
【従来の技術】
従来から、車両の閉断面のサイドフレームに液状の発泡材を充填して硬化させることにより、サイドフレームのエネルギ吸収特性を高めること知られている（例えば、特許文献１参照）。この従来技術では、サイドフレームの折り曲げ部に仕切り板を設定し、当該仕切り板により仕切られたサイドフレーム内の閉塞空間に発泡材が充填されている。この従来技術によれば、衝突時のサイドフレームの折り曲げ部での屈曲を防止することにより、サイドフレームのエネルギ吸収特性が向上する。
【０００３】
また、液状の発泡材を充填する際、仕切り板と壁面（例えば、閉断面のピラーの内壁面）との間に形成される僅かな隙間から発泡材が漏出するのを防止するため、発泡材を注入する前に粒状体を仕切り板上に層状に敷き詰めることが知られている（例えば、特許文献２参照）。この従来技術では、粒状体としてプラスティック製のペレットや金属の球が用いられている。この従来技術によれば、液状の発泡材を注入する前に粒状体により隙間を塞いでおくことにより、発泡材が当該隙間から漏出するのを防止することができる。
【０００４】
【特許文献１】
特開平１１−３４８８１３号公報
【０００５】
【特許文献２】
特開平９−２６７７６８号公報
【発明が解決しようとする課題】
【０００６】
しかしながら、上述の従来技術のように液状の発泡材を充填する場合、粘性の低い発泡材を用いると、上述の如く液状の発泡材が漏出するという問題点があり、粘性の高い発泡材を用いると、充填自体が困難であるという問題点がある。また、液状の発泡材は、一般的に高発泡率のものが多く、もっぱらシール材や遮音材として利用されているのが現状である。即ち、現時点において、強度や剛性を満足的に高めることができる液状の発泡材が存在せず、液状の発泡材は、強度や剛性を高める用途には不適切である。
【０００７】
これに対して、閉断面の部材の閉塞空間（充填空間）より僅かに小さい相似形にインジェクション成形した低発泡率の発泡材（以下、「成形発泡材」という）を当該閉塞空間に投入する構成も考えられる。この場合、液状の発泡材を充填する場合のように、発泡材の漏出の問題や、所望の強度や剛性が確保し難いという問題が生ずることはない。しかしながら、この場合、施工部位毎にインジェクション成形型を製作する必要があり、設備投資が嵩むという問題点がある。また、複雑な形状の閉断面の部材に対しては、屈曲部等で成形発泡材が干渉して投入することができず、投入タイミングに制約があるという問題点がある。特に、曲げパイプに対しては成形発泡材の施工自体が不能である。これは、成形発泡材がパイプの曲げ成形に追従せず、曲げ加工後のパイプに対しては成形発泡材投入時に干渉が生ずるためである。
【０００８】
そこで、本発明は、液状の発泡材や成形発泡材において生ずる上述の問題点を解決できる、車体構造及び車体用発泡材施工方法の提供を目的とする。
【０００９】
【課題を解決するための手段】
上記目的は、請求項１に記載する如く、閉断面の部材を備える車体構造であって、
前記閉断面の部材の少なくとも一部に、ペレット状の発泡材を充填して発泡させることを特徴とする、車体構造により達成される。
【００１０】
本発明によれば、液状の発泡材や成形発泡材に代わって、ペレット状の発泡材（粒状及び粉状の発泡材を含む）が閉断面の部材内で発泡されるので、液状の発泡材のような漏出の問題が生ずることはない。また、ペレット状の発泡材は、閉断面の部材に例えばエアーコンプレッサーにより充填することができるので、成形発泡材のように車種毎や適用箇所毎に成形型が必要となることがなく、また、あらゆる姿勢や形状の閉断面の部材に対しても充填が可能である。また、ペレット状の発泡材は、車体の組み立て工程中や塗装工程中に限らず、例えば閉断面の部材の製作時や車両の出荷後においても、充填が可能であり、充填タイミングに一切の制約もない。
【００１１】
従って、請求項２に記載する如く、前記ペレット状の発泡材を、塗装された前記閉断面の部材の断面内に充填することも可能であり、かかる場合、塗膜により保護された閉断面の部材に発泡材が充填されるので、当該閉断面の部材の防錆性能を高めることができる。
【００１２】
また、上記目的は、請求項３に記載する如く、閉断面の部材を有する車体に対する発泡材の施工方法であって、
前記閉断面の部材の少なくとも一部にペレット状の発泡材を充填する充填工程と、
前記ペレット状の発泡材を発泡させる発泡工程とを含むことを特徴とする、車両用発泡材施工方法により達成される。
【００１３】
本発明によれば、上述と同様、液状の発泡材や成形発泡材に代わって、ペレット状の発泡材（粒状及び粉状の発泡材を含む）が閉断面の部材内で発泡されるので、液状の発泡材のような漏出の問題が生ずることはない。また、充填工程は、閉断面の部材にペレット状の発泡材を例えばエアーコンプレッサーにより充填することにより実現することができるので、成形発泡材のように車種毎や適用箇所毎に成形型が必要となることがなく、また、あらゆる姿勢や形状の閉断面の部材に対しても実行可能である。また、充填工程は、発泡工程が後続する限り、車体の組み立て工程中や塗装工程中に限らず、例えば閉断面の部材の製作時や車両の出荷後に実行されてもよく、充填工程に一切の時間的な制約がない。尚、発泡工程は、車体の塗装工程中の熱を利用して実現されてよい。
【００１４】
また、請求項４に記載する如く、閉断面の部材の塗装後に充填工程が実行されてもよく、かかる場合、塗膜により保護された閉断面の部材に発泡材が充填されるので、当該閉断面の部材の防錆性能を高めることができる。
【００１５】
【発明の実施の形態】
以下、本発明の好ましい実施例について図面を参照して説明する。
【００１６】
図１は、本発明による発泡材の充填方法の一実施例を示す概念図である。本発明による発泡材の充填方法では、一般的な液状の発泡材の充填方法と同様に、サスペンションメンバやサイドメンバ等のような閉断面を有する部材１０（以下、「閉断面部材１０」という）に適切な箇所に仕切り板１４を設定し、当該仕切り板１４により仕切られた閉塞空間１２内に発泡材を充填することにより実現される。なお、閉断面部材１０の端部の開口が閉塞されている場合（例えば、パイプ状のビームの端部が潰されている場合や、接続部で完全に溶接されている場合等）には、仕切り板１４の設定が不要とされてもよい。
【００１７】
本発明では、閉断面部材１０の閉塞空間１２内には、液状ではなく固体の発泡材２０が充填される。発泡材２０は、その乾燥状態でペレット状の形態（顆粒状、粉末状、ビーズ状の形態を含む）を有している。このペレット状の発泡材２０は、エポキシ系樹脂、ポリスチレン系樹脂、ポリエチレン系樹脂、ポリプロピレン系樹脂、ポリエステル系樹脂、スチレン系改質ポリエチレン樹脂等のような合成樹脂発泡ビーズであってよい。発泡材２０の材料は、その用途に応じて適宜選択され、強度や剛性の向上（及び、車両衝突時の衝突エネルギの吸収特性の向上）を目的とした場合、例えば低発泡率（例えば、１．２〜１．３）の材料（例えば、エポキシ系樹脂）であってよく、シール材や遮音材として機能させる場合には、高発泡率の材料（低強度）であってよい。尚、ペレット状の発泡材２０の外形は、球形や直方形等を含むあらゆる立体形状であってよく（平面的な形状でもよい）、それぞれが同一形状を有する必要もない。
【００１８】
発泡材２０のサイズは、その発泡率に応じて決定されてよく、発泡率が小さいほど小さく設定される。即ち、発泡材２０のサイズ及び充填量は、その発泡率に応じて、発泡材２０の発泡後に閉塞空間１２内に空隙が形成されることがないように決定される。但し、発泡材２０のサイズは、必ずしも一定である必要はなく、発泡材２０間の隙間を埋める役割をするより小さなサイズの発泡材２０が混在してもよい。尚、低発泡率の発泡材２０のサイズとしては、例えば１〜３ｍｍ程度であってよい。
【００１９】
図１に示すように、閉断面部材１０には、発泡材２０を充填するための作業穴１０ａが設定されている。発泡材２０は、閉塞空間１２に作業穴１０ａを介して充填される。この発泡材２０の充填作業は、発泡材２０が上述の如くペレット状であるため、通常的なエアコンプレッサーを用いて実現することが可能である。従って、本実施例によれば、組み立てラインにおいて発泡材２０の充填作業のための特別な設備を設ける必要がなく、発泡材２０の充填タイミングの自由度が向上する。また、発泡材２０の充填作業は、車種の相異や充填箇所の相違に応じて異なることもなく、生産性が悪化することもない。
【００２０】
作業穴１０ａは、発泡材２０を充填する際の閉断面部材１０の姿勢や作業性に応じて、閉断面部材１０の適切な箇所に設定されてよい。例えば、図１（Ａ）に示すように、閉断面部材１０が縦向きである場合（即ち、閉塞空間１２の長手方向が鉛直面内である場合）、作業穴１０ａは閉塞空間１２の上側に設定される。この場合、作業穴１０ａからの発泡材２０の充填が開始されると、発泡材２０は、閉塞空間１２の底部（本例では、仕切り板１４の上面）から蓄積し始め、所定量充填された時点で作業穴１０ａから溢れ出す。この時点（若しくは直前）で、発泡材２０の充填作業が完了する。尚、発泡材２０の充填が完了すると、作業穴１０ａは、適切なプラグやグロメット等により塞がれる。
【００２１】
或いは、図１（Ｂ）に示すように、閉断面部材１０が縦向きである場合（即ち、閉塞空間１２の長手方向が水平面内である場合）、作業穴１０ａは閉塞空間１２の左右両側の２箇所に設定される。この場合、一方の作業穴１０ａを介して発泡材２０の充填が行われ、他方の作業穴１０ａから発泡材２０が溢れ出した時点（若しくは直前）で、発泡材２０の充填作業が完了する。従って、本実施例によれば、閉塞空間１２における作業穴１０ａの位置を適切に設定することで、発泡材２０の封入量を作業毎に予め設定することや作業時に充填量を監視・計測することなく、閉塞空間１２内に発泡材２０を必要十分な量だけ充填することが可能となる。
【００２２】
尚、本実施例では、上述の如く、発泡材２０の充填は、閉塞空間１２内にペレット状の発泡材２０をエア圧により噴射することにより実現されている。このため、本実施例によれば、如何なる姿勢の閉断面部材１０に対しても発泡材２０の充填が可能であると共に、如何なる形状の閉断面部材１０（例えば、屈曲部を有する閉断面部材１０や曲げパイプ）に対しても発泡材２０の充填が可能である。また、閉塞空間１２内に断面形状が局所的に小さい部位がある場合であっても、閉塞空間１２内の全体に発泡材２０を充填することが可能である。更に、本実施例の発泡材２０はペレット状であるため、閉断面部材１０に充填した後、当該閉断面部材１０の形状を変化させること（例えば、曲げ成形）ことも可能である。
【００２３】
本実施例のペレット状の発泡材２０は、閉断面部材１０に充填された後、車両の塗装工程で発泡する。具体的には、車両の組み立てラインで発泡材２０が充填された場合、発泡材２０は、下塗り工程後（電着塗装後）の乾燥路でその熱により発泡する。発泡後の発泡材２０は、閉断面部材１０の内壁１０ｂに直接的に密着した状態（接着状態）となる。このため、発泡材２０が閉断面部材１０の内壁１０ｂから容易に脱離することはない。
【００２４】
一方、本実施例では、上述の如く発泡材２０の充填タイミングに制約がないため、下塗り工程後（電着塗装後）の乾燥路の後に、発泡材２０を閉断面部材１０に充填することも可能である。この場合、発泡材２０は、中塗り工程や上塗り工程後の乾燥路でその熱により発泡するため、発泡後の発泡材２０は、閉断面部材１０の内壁１０ｂの塗膜上に密着した状態となる。従って、本実施例によれば、塗装後の閉断面部材１０に発泡材２０を充填することにより、閉断面部材１０の防錆性能を高めることができる。尚、防錆性能を高めるための発泡材２０の充填は、後に発泡材２０の発泡に必要な熱が印加される限り、中塗り工程や上塗り工程後、若しくは、車両出荷後（補修用）に実行されてもよい。
【００２５】
ところで、本実施例では、上述の如く、発泡材２０の充填直後に発泡材２０の発泡が実現されるのではなく（但し、これも可能ではある）、発泡材２０の充填後、所定の工程を経た後、塗装工程の乾燥路の熱を利用して発泡材２０の発泡が実現されている。従って、発泡材２０の充填後（特に、組み立てラインで充填した場合）に所定の工程を経る場合には、発泡材２０の閉塞空間１２からの漏出が問題となる。これに関して、本実施例によれば、発泡材２０がペレット状であるため、閉断面部材１０の内壁１０ｂと仕切り板１４との間に僅かな隙間がある場合であっても、当該隙間を通って発泡材２０が閉塞空間１２内から漏出することがない。換言すると、本実施例によれば、発泡材２０がペレット状であり発泡材２０の漏出の問題が生じないため、発泡材２０の充填タイミングに制約がなく、組み立てラインや塗装工程の如何なる段階においても、更には閉断面部材１０のサブアセンブリ時（即ち、組み立てラインに搬入される前）や車両出荷後においても、発泡材２０の充填を行うことが可能である。
【００２６】
尚、対照的に、液状の発泡材を閉断面部材に充填する場合、閉断面部材の内壁と仕切り板との間の僅かな隙間からの発泡材の漏出の問題が発生するだけでなく、発泡材の充填タイミングにも一定の制約がある。例えば、液状の発泡材を用いた場合、２液を混合した際の化学反応により発泡・硬化が実現されるが、別の液の混入や塗膜への影響を考慮すると、塗装工程中に液状の発泡材を充填することは望ましくない。
【００２７】
次に、本発明の車両における施工箇所について概説する。図２は、剛性向上を目的とした本発明による発泡材２０の施工例を示し、図３は、強度向上を目的とした本発明による発泡材２０の施工例を示している。
【００２８】
図２に示す施工例では、ペレット状の発泡材２０は、リアサスペンション回りの剛性向上を目的として、井型構造のリアサスペンションメンバを構成する車幅方向の閉断面部材４０及び左右の丸パイプ４２の閉じ断面内の全体に充填されている（図中、充填箇所をハッチングにより指示）。また、図３に示す施工例では、ペレット状の発泡材２０は、強度が必要となる箇所に応じて、各ピラー４４の閉じ断面内、フロントサイドメンバ４６の閉じ断面内、ロッカー４８の閉じ断面内に局所的に充填されている（図中、充填箇所をハッチングにより指示）。尚、図２及び図３に示す施工例では、発泡材２０としては、高い強度を有する低発泡率の発泡材が選択されている。
【００２９】
このように、本発明による発泡材２０は、上述の如く、充填する閉断面部材１０の形状・断面形状や充填範囲に制約がなく、また、充填作業時の閉断面部材１０の姿勢や充填タイミングに制約がないため、車体におけるあらゆる閉断面部材１０に対して施工することが可能である。
【００３０】
以上、本発明の好ましい実施例について詳説したが、本発明は、上述した実施例に制限されることはなく、本発明の範囲を逸脱することなく、上述した実施例に種々の変形及び置換を加えることができる。
【００３１】
例えば、上述した実施例では、車体の各部へのペレット状の発泡材の適用例に対して言及されているが、本発明は、車両に限ることなく、二輪車や自転車、航空機や鉄道等の各種構造物、及び、その他の構造物に対しても適用可能である。
【００３２】
【発明の効果】
本発明によれば、液状の発泡材や成形発泡材に代わって、ペレット状の発泡材が閉断面の部材内で発泡されるので、液状の発泡材のような漏出の問題が生ずることがなく、信頼性が向上する。また、ペレット状の発泡材は、閉断面の部材に例えばエアーコンプレッサーにより充填することができるので、成形発泡材のような特別な設備や成形型が必要となることがなく、また、あらゆる姿勢や形状の閉断面の部材に対しても充填が可能であり、生産性が向上する。
【図面の簡単な説明】
【図１】本発明による発泡材の充填方法の一実施例を示す概念図である。
【図２】剛性向上を目的とした本発明による発泡材の施工例を示す図である。
【図３】強度向上を目的とした本発明による発泡材の施工例を示す図である。
【符号の説明】
１０ 閉断面部材
１０ａ 作業穴
１０ｂ 閉断面部材の内壁
１２ 閉塞空間
１４ 仕切り板
２０ 発泡材[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a vehicle body structure having a member having a closed cross section filled with a foam material, and a method of constructing a foam material in a vehicle body having a member having a closed cross section.
[0002]
[Prior art]
2. Description of the Related Art It has been known that the energy absorption characteristics of a side frame are enhanced by filling and curing a liquid foam material in a side frame having a closed cross section of a vehicle (for example, see Patent Document 1). In this conventional technique, a partition plate is set in a bent portion of a side frame, and a closed space in the side frame partitioned by the partition plate is filled with a foam material. According to this conventional technique, the energy absorption characteristics of the side frame are improved by preventing the side frame from bending at the bent portion at the time of collision.
[0003]
Further, when the liquid foam material is filled, the foam material is prevented from leaking from a slight gap formed between the partition plate and the wall surface (for example, the inner wall surface of the pillar having a closed cross section). It is known that a granular material is spread in layers on a partition plate before injecting the powder (see, for example, Patent Document 2). In this conventional technique, a plastic pellet or a metal sphere is used as the granular material. According to this conventional technique, by closing the gap with the granular material before injecting the liquid foam material, it is possible to prevent the foam material from leaking from the gap.
[0004]
[Patent Document 1]
Japanese Patent Application Laid-Open No. H11-348813
[Patent Document 2]
JP 9-267768 A [Problems to be Solved by the Invention]
[0006]
However, when a liquid foam material is filled as in the above-described conventional technique, when a low-viscosity foam material is used, there is a problem that the liquid foam material leaks as described above, and a high-viscosity foam material is used. There is a problem that the filling itself is difficult. In addition, liquid foam materials generally have a high foaming rate, and are currently used exclusively as seal materials and sound insulation materials. That is, at present, there is no liquid foaming material capable of satisfactorily increasing the strength and rigidity, and the liquid foaming material is unsuitable for use in increasing the strength and rigidity.
[0007]
In contrast, a configuration in which a low-foaming-rate foam material (hereinafter, referred to as “molded foam material”) that is injection-molded into a similar shape slightly smaller than the closed space (filled space) of the member having the closed cross section is injected into the closed space. Is also conceivable. In this case, unlike the case of filling with a liquid foam material, there is no problem of leakage of the foam material and a problem that it is difficult to secure desired strength and rigidity. However, in this case, it is necessary to manufacture an injection mold for each construction site, and there is a problem that capital investment increases. Further, there is a problem in that a molded foamed material cannot be injected into a member having a closed cross section having a complicated shape due to interference at a bent portion or the like, and there is a restriction on the injection timing. In particular, it is impossible to apply a molded foam material to a bent pipe. This is because the molded foam does not follow the bending of the pipe, and interference occurs when the molded foam is injected into the bent pipe.
[0008]
Therefore, an object of the present invention is to provide a vehicle body structure and a method of constructing a foam material for a vehicle body, which can solve the above-mentioned problems occurring in a liquid foam material or a molded foam material.
[0009]
[Means for Solving the Problems]
The object is to provide a vehicle body structure including a member having a closed cross section, as described in claim 1,
At least a part of the member having the closed cross section is filled with a pellet-like foaming material and foamed to achieve foaming.
[0010]
ADVANTAGE OF THE INVENTION According to this invention, instead of a liquid foaming material and a molded foaming material, a pellet-like foaming material (including a granular and powdery foaming material) is foamed in a member having a closed cross section. Such a leakage problem does not occur. Further, since the foamed material in the form of a pellet can be filled into a member having a closed cross-section by, for example, an air compressor, a molding die is not required for each vehicle type or each application location unlike a molded foamed material, It is possible to fill a member having a closed cross section of any posture and shape. In addition, the pellet-like foam material can be filled not only during the assembly process or the painting process of the vehicle body, but also during the production of a member having a closed cross section or after shipment of the vehicle, for example, and there are no restrictions on the filling timing. Nor.
[0011]
Therefore, as described in claim 2, it is also possible to fill the foamed material in the form of pellets into the cross section of the painted member having the closed cross section, in which case, the closed cross section protected by the coating film. Since the member is filled with the foam material, the rust prevention performance of the member having the closed cross section can be enhanced.
[0012]
In addition, the object is a method of applying a foam material to a vehicle body having a member having a closed cross section, as described in claim 3,
A filling step of filling at least a part of the closed-section member with a pellet-shaped foam material,
And a foaming step of foaming the pellet-like foam material.
[0013]
According to the present invention, similarly to the above, instead of the liquid foaming material or the molded foaming material, a pellet-like foaming material (including a granular and powdery foaming material) is foamed in a member having a closed cross section, There is no leakage problem like liquid foam. In addition, since the filling step can be realized by filling a closed-section member with a pellet-shaped foam material by, for example, an air compressor, a molding die is required for each vehicle type and each application location like a molded foam material. The present invention can be applied to a member having a closed cross section having any posture and shape. In addition, the filling step is not limited to the assembly step of the vehicle body or the painting step as long as the foaming step follows, and may be performed, for example, at the time of producing a member having a closed cross section or after shipping the vehicle. There is no time constraint. In addition, the foaming process may be realized by using heat during a vehicle body painting process.
[0014]
Further, as described in claim 4, the filling step may be performed after the coating of the member having the closed cross section. In such a case, the member having the closed cross section protected by the coating film is filled with the foaming material. The rust prevention performance of the member having the cross section can be enhanced.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
[0016]
FIG. 1 is a conceptual diagram showing one embodiment of a method for filling a foam material according to the present invention. In the method of filling a foam material according to the present invention, similarly to a general method of filling a liquid foam material, a member 10 having a closed section such as a suspension member or a side member (hereinafter, referred to as a “closed section member 10”). This is realized by setting a partition plate 14 at an appropriate location and filling the closed space 12 partitioned by the partition plate 14 with a foaming material. When the opening at the end of the closed section member 10 is closed (for example, when the end of the pipe-shaped beam is crushed or completely welded at the connection portion), The setting of the partition plate 14 may not be required.
[0017]
In the present invention, the closed space 12 of the closed section member 10 is filled with a solid foam material 20 instead of a liquid. The foamed material 20 has a pellet-like form (including a granular form, a powdery form, and a bead-like form) in its dry state. The pellet-shaped foam material 20 may be a synthetic resin foam bead such as an epoxy resin, a polystyrene resin, a polyethylene resin, a polypropylene resin, a polyester resin, a styrene-modified polyethylene resin, or the like. The material of the foam material 20 is appropriately selected according to its use, and when the purpose is to improve the strength and rigidity (and to improve the absorption property of the collision energy at the time of a vehicle collision), for example, a low foaming ratio (for example, 1) .2 to 1.3) (for example, an epoxy resin), and when it functions as a sealing material or a sound insulating material, a material having a high foaming rate (low strength) may be used. The outer shape of the pellet-shaped foam material 20 may be any three-dimensional shape including a spherical shape or a rectangular shape (a planar shape may be used), and it is not necessary that the respective shapes have the same shape.
[0018]
The size of the foam material 20 may be determined according to the foaming rate, and is set smaller as the foaming rate is smaller. That is, the size and the filling amount of the foam material 20 are determined in accordance with the foaming ratio so that no void is formed in the closed space 12 after the foam material 20 foams. However, the size of the foam material 20 is not necessarily required to be constant, and a foam material 20 having a smaller size that plays a role of filling a gap between the foam materials 20 may be mixed. The size of the foaming material 20 having a low foaming rate may be, for example, about 1 to 3 mm.
[0019]
As shown in FIG. 1, a working hole 10 a for filling the foam material 20 is set in the closed section member 10. The foam material 20 fills the closed space 12 through the working hole 10a. Since the foaming material 20 is in the form of pellets as described above, the filling operation of the foaming material 20 can be realized by using a general air compressor. Therefore, according to the present embodiment, there is no need to provide a special facility for the filling operation of the foam material 20 in the assembly line, and the flexibility of the filling timing of the foam material 20 is improved. In addition, the filling operation of the foam material 20 does not differ depending on the difference of the vehicle type or the difference of the filling location, and the productivity does not deteriorate.
[0020]
The work hole 10a may be set at an appropriate position on the closed-section member 10 according to the posture and workability of the closed-section member 10 when filling the foam material 20. For example, as shown in FIG. 1A, when the closed cross-section member 10 is vertical (that is, when the longitudinal direction of the closed space 12 is in a vertical plane), the working hole 10 a is located above the closed space 12. Is set. In this case, when the filling of the foam material 20 from the work hole 10a is started, the foam material 20 starts to accumulate from the bottom of the closed space 12 (in this example, the upper surface of the partition plate 14) and is filled with a predetermined amount. At this point, it overflows from the work hole 10a. At this point (or immediately before), the filling operation of the foam material 20 is completed. When the filling of the foam material 20 is completed, the working hole 10a is closed by an appropriate plug, grommet, or the like.
[0021]
Alternatively, as shown in FIG. 1B, when the closed cross-section member 10 is vertically oriented (that is, when the longitudinal direction of the closed space 12 is in a horizontal plane), the working holes 10 a are on the left and right sides of the closed space 12. It is set in two places. In this case, the filling of the foam material 20 is performed through the one working hole 10a, and the filling operation of the foam material 20 is completed when (or immediately before) the foam material 20 overflows from the other working hole 10a. Therefore, according to the present embodiment, by appropriately setting the position of the work hole 10a in the closed space 12, the amount of the foamed material 20 to be filled can be set in advance for each work, and the filling amount can be monitored and measured during the work. Without filling, it is possible to fill the closed space 12 with the necessary and sufficient amount of the foam material 20.
[0022]
In the present embodiment, as described above, the filling of the foam material 20 is realized by injecting the pellet-like foam material 20 into the closed space 12 by air pressure. For this reason, according to the present embodiment, the foamed material 20 can be filled into the closed section member 10 in any posture, and the closed section member 10 having any shape (for example, the closed section member 10 having a bent portion) can be filled. And the bent pipe) can be filled with the foam material 20. Further, even when there is a locally small cross-sectional shape in the closed space 12, the entirety of the closed space 12 can be filled with the foam material 20. Furthermore, since the foamed material 20 of the present embodiment is in the form of a pellet, it is possible to change the shape of the closed-section member 10 (for example, bending) after filling the closed-section member 10.
[0023]
The pellet-shaped foam material 20 of the present embodiment foams in a vehicle coating process after being filled in the closed-section member 10. Specifically, when the foam material 20 is filled in the assembly line of the vehicle, the foam material 20 is foamed by the heat in the drying path after the undercoating process (after the electrodeposition coating). The foamed material 20 after foaming is in a state of being directly adhered to the inner wall 10b of the closed-section member 10 (adhered state). Therefore, the foam material 20 is not easily detached from the inner wall 10b of the closed section member 10.
[0024]
On the other hand, in the present embodiment, since there is no restriction on the filling timing of the foam material 20 as described above, the foam material 20 may be filled in the closed section member 10 after the drying path after the undercoating step (after the electrodeposition coating). It is possible. In this case, since the foamed material 20 is foamed by the heat in the drying path after the intermediate coating process and the overcoating process, the foamed material 20 after the foaming is in a state in which the foamed material 20 is in close contact with the coating film on the inner wall 10 b of the closed-section member 10. Become. Therefore, according to the present embodiment, the rust prevention performance of the closed-section member 10 can be enhanced by filling the foamed material 20 into the closed-section member 10 after coating. The filling of the foam material 20 for improving the rust prevention performance is performed after the intermediate coating process or the top coating process, or after the vehicle is shipped (for repair) as long as heat necessary for foaming the foam material 20 is applied later. It may be performed.
[0025]
By the way, in the present embodiment, as described above, foaming of the foam material 20 is not realized immediately after the filling of the foam material 20 (however, this is also possible). After that, foaming of the foam material 20 is realized by utilizing heat of the drying path in the coating process. Therefore, if a predetermined process is performed after the filling of the foam material 20 (particularly when the filling is performed in an assembly line), leakage of the foam material 20 from the closed space 12 becomes a problem. In this regard, according to the present embodiment, since the foam material 20 is in the form of a pellet, even if there is a slight gap between the inner wall 10b of the closed-section member 10 and the partition plate 14, the foam material 20 passes through the gap. Therefore, the foam material 20 does not leak from the closed space 12. In other words, according to the present embodiment, since the foam material 20 is in the form of pellets and the problem of leakage of the foam material 20 does not occur, there is no restriction on the filling timing of the foam material 20, and any stage of the assembly line or the painting process can be performed. Further, the foam material 20 can be filled even at the time of sub-assembly of the closed section member 10 (that is, before being carried into the assembly line) or after shipment of the vehicle.
[0026]
In contrast, when the liquid foam material is filled in the closed-section member, not only the problem of leakage of the foam material from a small gap between the inner wall of the closed-section member and the partition plate occurs, but also the foaming occurs. There are also certain restrictions on the timing of material filling. For example, when a liquid foaming material is used, foaming and hardening are realized by a chemical reaction when two liquids are mixed. However, considering the mixing of another liquid and the effect on the coating film, the liquid Is not desirable.
[0027]
Next, the construction location in the vehicle of the present invention will be outlined. FIG. 2 shows an example of application of the foam material 20 according to the present invention for improving rigidity, and FIG. 3 shows an example of application of the foam material 20 according to the present invention for improving strength.
[0028]
In the construction example shown in FIG. 2, the pellet-shaped foam material 20 is a vehicle-width-direction closed cross-section member 40 and left and right round pipes 42 that constitute a well-shaped rear suspension member for the purpose of improving rigidity around the rear suspension. Is filled in the entire closed cross section (in the figure, the filled portion is indicated by hatching). In the construction example shown in FIG. 3, the pellet-shaped foamed material 20 has a closed cross section of each pillar 44, a closed cross section of the front side member 46, and a closed cross section of the rocker 48, depending on the location where strength is required. Is filled locally (in the figure, the filling location is indicated by hatching). In the construction examples shown in FIGS. 2 and 3, as the foam material 20, a foam material having high strength and a low foaming rate is selected.
[0029]
As described above, as described above, the foamed material 20 according to the present invention has no restriction on the shape, cross-sectional shape, and filling range of the closed cross-sectional member 10 to be filled, and the posture and the filling timing of the closed cross-sectional member 10 during the filling operation. , There is no restriction, so that it can be applied to any closed section member 10 in the vehicle body.
[0030]
Although the preferred embodiment of the present invention has been described in detail, the present invention is not limited to the above-described embodiment, and various modifications and substitutions can be made to the above-described embodiment without departing from the scope of the present invention. Can be added.
[0031]
For example, in the above-described embodiment, the application example of the pellet-shaped foam material to each part of the vehicle body is referred to. It is also applicable to structures and other structures.
[0032]
【The invention's effect】
According to the present invention, in place of a liquid foam material or a molded foam material, a pellet-like foam material is foamed in a member having a closed cross section, so that a problem of leakage like a liquid foam material does not occur. , Reliability is improved. Further, since the foamed material in the form of a pellet can be filled into a member having a closed cross section by, for example, an air compressor, there is no need for special equipment or a molding die such as a molded foamed material. It is possible to fill even a member having a closed cross section of the shape, and productivity is improved.
[Brief description of the drawings]
FIG. 1 is a conceptual diagram showing one embodiment of a method for filling a foam material according to the present invention.
FIG. 2 is a view showing an example of application of a foam material according to the present invention for the purpose of improving rigidity.
FIG. 3 is a diagram showing an example of applying a foam material according to the present invention for the purpose of improving strength.
[Explanation of symbols]
Reference Signs List 10 Closed section member 10a Work hole 10b Inner wall 12 of closed section member Closed space 14 Partition plate 20 Foam material
