JP3630555B2

JP3630555B2 - Subframe structure of a three-wheel dump truck

Info

Publication number: JP3630555B2
Application number: JP11710098A
Authority: JP
Inventors: 廣行小倉
Original assignee: Kyokuto Kaihatsu Kogyo Co Ltd
Current assignee: Kyokuto Kaihatsu Kogyo Co Ltd
Priority date: 1998-04-27
Filing date: 1998-04-27
Publication date: 2005-03-16
Anticipated expiration: 2018-04-27
Also published as: JPH11310154A

Description

【０００１】
【発明の属する技術分野】
本発明は、荷箱を後方及び両側方に選択的にダンプさせることが可能な三転ダンプカーにおける荷箱の下の車体床面に設けられるサブフレーム構造に関する。
【０００２】
【従来の技術】
一般に、三転ダンプカーは、例えば特開平９−２２６４３８号公報に開示されているように、荷箱と車体との間における前後左右の４箇所にヒンジ装置を設ける必要があり、そのために、車体の床部分にサブフレームと呼ばれる構造部材が設けられる。
上記サブフレームは、車両の前後方向を長手方向とする一対の主桁と、車両の幅方向を長手方向として主桁と直交交差する一対の横桁とにより井桁状に構成されており、上記ヒンジ装置は各横桁の両端に設けられている。主桁と横桁との直交交差部は、ダンプカーの床位置をなるべく低くするため、単なる重ね合わせではなく、主桁に形成された穴に横桁を挿入するか、又は主桁に形成された切欠部に横桁を上から挿入する構造が必要である。しかし、主桁に形成された穴に横桁を挿入する構造は、主桁と横桁との溶接が容易でないか若しくは作業能率が悪くなる等の問題があるため、一般には、ヒンジ装置を取り付けた横桁を、主桁に形成された切欠部に上から挿入する構造が採用されている。
【０００３】
図１０は、主桁１０１に形成された切欠部１０１ａに、横桁１０２を上から挿入する従来のサブフレーム構造の一例を示す斜視図である。この場合、横桁１０２の挿入後、横桁固定用の補助ブラケット１０３が切欠部１０１ａに装着され、この補助ブラケット１０３と主桁１０１及び横桁１０２とを溶接することによって、主桁１０１と横桁１０２とが相互に固定される。
【０００４】
【発明が解決しようとする課題】
しかしながら、上記のような従来の三転ダンプカーのサブフレーム構造においては、補助ブラケット１０３と主桁１０１とを、互いに端面を突き合わせた状態で溶接（突合せ溶接）しなければならず、このような溶接作業は両部材の寸法誤差と相まって、一般に容易でない。従って、確実な溶接を行うことは困難であった。
一方、端面同士が正確にレベルをそろえて突き合わせされていない状態で溶接されると、主桁１０１の上面より上方に補助ブラケット１０３が突出することがある。また、溶接の肉盛りが主桁１０１の上面に形成されて、突起部を構成する。このような場合、主桁１０１の上面に配置される荷箱載置用の受け木（図示せず）が安定しない。
【０００５】
上記のような従来の問題点に鑑み、本発明は、主桁の上面に突出部や突起部が存在せず、かつ、主桁・横桁の交差部における確実な溶接が可能な三転ダンプカーのサブフレーム構造を提供することを目的とする。
【０００６】
【課題を解決するための手段】
本発明の三転ダンプカーのサブフレーム構造は、▲１▼長手方向に直交する断面が略矩形のボックス状部材であって、一側面部、上面部及び他側面部に連続してそれぞれ形成された第１切欠部、第２切欠部及び第３切欠部を有する主桁と、▲２▼前記主桁と直交する方向を長手方向として前記第２切欠部側から前記主桁に交差状態で挿入される部材であって、前記第１切欠部内及び前記第３切欠部内の所定領域を通過して配置された横桁と、▲３▼前記横桁が通過した前記第１切欠部の残余開口領域より広い面領域を有し、前記主桁の一側面部の外面に当接して前記残余開口領域を塞ぐ第１面部、この第１面部と直交して前記第１切欠部の開口幅以下の幅で形成され、前記第２切欠部の開口領域より広い面領域を有し、前記主桁の上面部の内面に当接して前記第２切欠部の開口領域を塞ぐ第２面部、及び、この第２面部と直交して前記第１面部に平行に形成され、前記横桁が通過した前記第３切欠部の残余開口領域より広く且つ前記第１切欠部の残余開口領域の範囲内に相当する面領域を有し、前記主桁の他側面部の内面に当接して前記第３切欠部の残余開口領域を塞ぐ第３面部を有して成り、前記主桁及び横桁との当接部境界線に沿って溶接された横桁固定用部材とを備えたものである（請求項１）。
【０００７】
このように構成された三転ダンプカーのサブフレーム構造においては、横桁固定用部材の第１〜第３面部が、それぞれ、主桁の内面又は外面に当接して、横桁が主桁と交差した状態における第１〜第３切欠部の開口領域を塞ぐ。これにより、横桁固定用部材の第１面部及び第３面部は、横桁に対して直交交差の関係になるとともに、第１〜第３面部は、主桁に対して重ね合わせの関係になり、部材端面同士の突き合わせ状態は存在しない。一方、第２面部は主桁上面部の内面に当接して第２切欠部を塞ぐため、段差が形成されて当該第２面部の上面は主桁の上面より常に低い位置にある。また、横桁固定用部材の上面と第２切欠部の端面とによって構成される隅の部分が主桁上面側の溶接部位となる。
【０００８】
前記サブフレーム構造（請求項１）において、横桁固定用部材は、台形板状材の上底及び下底から内方にそれぞれ横桁を挿通させるための切欠部を形成した展開形状であって、上底又は下底に平行な２本の線に沿ってコの字状に折り曲げることにより下底側から順に第１面部、第２面部及び第３面部が構成されてもよい（請求項２）。
この場合、横桁固定用部材は、第１面部の下底側から幅が漸次狭くなる形状となる。第１面部内における幅の変化部分は主桁の外面への「当接代」となる。
【０００９】
前記サブフレーム構造（請求項１）において、第１面部の最小幅が、第１切欠部の対応する開口幅と略一致していてもよい（請求項３）。
この場合、第１面部が第１切欠部を完全に塞ぎ、実質的に隙間は生じない。
【００１０】
【発明の実施の形態】
図１〜８は、本発明の一実施形態による三転ダンプカーのサブフレーム構造に関する図である。なお、各図は、サブフレーム構造のうち、本発明の説明に必要な部材に限定して示しており、その他の構造上の部材については図示を省略している。
まず、サブフレームの全体構造について図７及び図８を参照して説明する。図７はサブフレーム１０の平面図、図８は図７のＶＩＩＩ−ＶＩＩＩ線断面から見た図である。各図の左方が車体（図示せず）の前方、右方が後方に相当する。図７において、一対の主桁１は、車体の前後方向を長手方向として互いに平行に設けられており、長手方向に直交する断面形状が略矩形のボックス状部材である。
【００１１】
一方、一対の横桁２は、パイプ状の部材であり、車体の幅方向を長手方向として主桁１と直交交差して配置されている。そして、主桁１と横桁２とは交差する４箇所で相互に溶接されている。また、各横桁２の両端部にはヒンジ装置４が取り付けられている。後方側横桁２の内部には回転軸３がその軸心周りに横桁２に対して回転自在に支持されており、ヒンジ装置４の一部が回転軸３と接続されている。なお、主桁１の前方側端部間にクロス部材５が取り付けられている。
ダンプカーの荷箱（図示せず。）を後方にダンプさせるときは、前方のヒンジ装置４がロック解除され、上記回転軸３を支軸にして荷箱が傾動する。また、荷箱を側方にダンプさせるときは、左右いずれか一方側の一対のヒンジ装置４がロック解除され、他方側の一対のヒンジ装置４を支点として荷箱が傾動する。
次に、前方側の横桁２と主桁１との交差部における接続構造について詳細に説明する。
【００１２】
図１〜４は、主桁１と横桁２との交差部（図７の符号Ｘで示す部分）における接続構造を示す斜視図であり、図１は後述する補助ブラケット６の取付途中の状態を、図２は補助ブラケット取付前の状態を、図３は補助ブラケット６取付後の状態を、図４はさらに溶接後の状態をそれぞれ示している。また、図５の（ａ）及び（ｂ）はそれぞれ、交差部における主桁１のみについての、図２のＡ矢視側面図及びＢ矢視側面図である。
【００１３】
図５の（ａ）において、主桁１の一側面部には、幅Ｗ１で高さＨの矩形開口を形成する切欠部１ａ１と、その中央部から下方に直径Ｗ２（＜Ｗ１）の半円状開口を形成する切欠部１ａ２とからなる第１切欠部１ａが設けられている。また、主桁１の上面部１ｂには、第１切欠部１ａと連続して、幅Ｗ２の矩形開口を形成する第２切欠部１ｃが設けられている。一方、（ｂ）に示すように、主桁１の他側面部には、第２切欠部１ｃと連続して、Ｕ字状の開口を形成する第３切欠部１ｄが設けられている。この第３切欠部１ｄの幅及び底部半円形の直径は、Ｗ２である。このＷ２の値は、横桁２の外径に、ごく僅かのクリアランス分を付加したものである。上記のような切欠形態によれば、第３切欠部１ｄの開口領域は第１切欠部１ａの開口領域に相当する範囲内に存在する関係にあり、第２切欠部１ｃの開口幅は、第１切欠部１ａの開口幅以下の関係にある。
【００１４】
図２は、上記のような第１〜第３切欠部１ａ、１ｃ及び１ｄを有する主桁１に直交交差して、横桁２が配置された状態を示している。前述のように第２切欠部１ｃ及び第３切欠部１ｄの幅Ｗ２が横桁２の外径より僅かに大きいため、横桁２は主桁１に交差して挿入され、切欠部１ａ２及び第３切欠部１ｄの下部円弧部に接した状態となる。
【００１５】
次に、図１に示すように、補助ブラケット６を装着する。ここで、補助ブラケット６とは横桁固定用部材であり、折り曲げ加工前において図６の（ａ）に示す展開形状を有している。また、折り曲げ加工後には図６の（ｂ）に示す形状となる。（ａ）及び（ｂ）に示すように、補助ブラケット６は、台形の鋼板の下底及び上底から内方にそれぞれＵ字形の切欠部６ａ及び６ｂを設けたものを、上底又は下底に平行な点線Ｌ１及びＬ２のところで直角に折り曲げて、略「コ」の字形状にしたものである。折り曲げ加工後の補助ブラケット６は、（ｂ）に示すように、切欠部６ａを有する第１面部６１と、この第１面部６１と直交する第２面部６２と、切欠部６ｂを有し、第２面部６２と直交して第１面部６１と平行な第３面部６３とを備えている。切欠部６ａ及び６ｂの幅及び各円弧部の直径は、前述の幅Ｗ２と同値である。点線Ｌ１で折り曲げされる部分の幅Ｗ１は図５に示す切欠部１ａ１の幅Ｗ１と等しい（実際には、製造誤差を考慮して、切欠部１ａ１の幅Ｗ１の値より若干小さい値としてもよい。）。点線Ｌ２で折り曲げされる部分の幅Ｗ３は、幅Ｗ１より小さく、かつ、幅Ｗ２より大きい。また、第１面部６１の下端の幅Ｗ４は、幅Ｗ１より大きい。すなわち、各幅は、Ｗ４＞Ｗ１＞Ｗ３＞Ｗ２の関係にある。
【００１６】
図６の（ｂ）において、補助ブラケット６の板厚をｔ１、第２面部６２の奥行き（外法）をＤ１とし、図２における主桁１の板厚をｔ２、奥行き（外法）をＤ２とすると、Ｄ１−ｔ１＝Ｄ２−ｔ２である。従って、板厚ｔ１とｔ２とが同じである場合は、Ｄ１＝Ｄ２となる。
また、図６の（ｂ）に示す補助ブラケット６の第３面部６３の高さＨは、図５の（ａ）における切欠部１ａ１の高さＨと同値である。
【００１７】
上記のような形態の補助ブラケット６は、図１に示すように、切欠部１ａ１が設けられた側の主桁１の側面から装着される。このとき、前述のように、補助ブラケット６の第３面部６３の最大幅（Ｗ３）は切欠部１ａ１の幅（Ｗ１）より小さく、かつ、第３面部６３の高さ（Ｈ）は切欠部１ａ１の高さと等しい。また、第１面部６１及び第３面部６３にはそれぞれ横桁２の外径に合致した切欠部６ａ及び６ｂが設けられている（図６）。従って、第３面部６３は、第１切欠部１ａの開口領域のうち横桁２が挿通された領域を除く残余開口領域を通過できる。そして、横桁２の軸方向に補助ブラケット６を押し込んだ状態を図３に示す。
【００１８】
図１及び図３において、補助ブラケット６の第１面部６１の最小幅Ｗ１が切欠部１ａ１の幅と同値であり、最大幅Ｗ４は切欠部１ａ１の幅より大きいため、第１面部６１の内面は主桁１の一側面部１ｅ（手前側）の外面に当接して、切欠部１ａ１のうち横桁２が挿通された領域を除く残余の開口領域を塞ぐ。また、第２面部６２の幅（Ｗ３以上でＷ１以下）は第２切欠部１ｃの幅Ｗ２より大きいため、第２面部６２の上面は主桁１の上面部１ｂの内面に当接して第２切欠部１ｃの開口領域を塞ぐ。さらに、第３面部６３の幅（Ｗ２より大きく、Ｗ３以下）は第３切欠部１ｄの幅Ｗ２より大きいため、第３面部６３の外側面は、主桁１の他側面部１ｆの内面に当接して、第３切欠部１ｄのうち横桁２が挿通された領域を除く残余の開口領域を塞ぐ。この場合、前述の、Ｄ１−ｔ１＝Ｄ２−ｔ２の関係により、第１面部６１及び第３面部６３は、主桁１の一側面部１ｅの外面及び他側面部１ｆの内面にそれぞれ隙間なく当接する。
【００１９】
この結果、補助ブラケット６は主桁１の両側面部及び上面部に対して、すべて平面同士の重ね合わせの関係で当接した状態となり、部材端面同士の突き合わせ状態は存在しない。また、第２面部６２は主桁１の上面部１ｂの内面に当接して第２切欠部１ｃの開口領域を塞ぐため、段差が形成されて第２面部６２の上面は主桁１の上面より常に低い位置にある。従って、補助ブラケット６が主桁１の上面から上方へ突出することはあり得ない。
【００２０】
その後、図４の（ａ）及び（ａ）の背面側から見た斜視図である（ｂ）に示すように、部材同士の当接部境界線に沿った隅部に連続して溶接（溶接部位を太線で示す。）が施され、主桁１と補助ブラケット６とが、また、補助ブラケット６と横桁２とがそれぞれ固定される。溶接部位には、部材端面同士の突合せ溶接部分がないため、溶接が容易であるとともに、確実な溶接を行うことができる。
一方、主桁１の上面側における溶接は、主桁１の上面より板厚分だけ段差のある補助ブラケット６の上面と第２切欠部１ｃの端面（板厚の部分）とによって構成される隅で行われる。従って、溶接による肉盛り分の上方突出が段差内に吸収され、肉盛りが主桁１の上面より上方へ突出することを防止できる。
【００２１】
また、上記実施形態とは別に、仮に、補助ブラケット６の第１面部６１上端側の幅が、主桁１の切欠部１ａ１の幅より小さい場合には、図９に示すように、補助ブラケット６取付時に隙間Ｇができ、第１面部６１の左右端部の溶接部位に応力の集中が起こる。この結果、点Ｐで示す部分から補助ブラケット６に亀裂が生じやすくなる。しかしながら、上記実施形態においては、補助ブラケット６の第１面部６１上端側の幅Ｗ１が、主桁１の切欠部１ａ１の幅と一致していることにより、第１面部６１の左右両端部全域が溶接され、応力を均等に分散させる。従って、上記のような亀裂の発生を防止することができる。
【００２２】
なお、上記実施形態において、補助ブラケット６は、図６に示すように、展開形状の基本的形態が台形であるものを示したが、これに限らず種々の形態が可能である。例えば、第２面部６２と第３面部６３とは同一幅であってもよいし、第２面部６２のみが同一幅であってもよい。また、第１面部６１が他面部より幅広の同一幅であってもよい。しかしながら、台形を基本的形態とする本実施形態の補助ブラケット６は、材料面積が少なく、製造が容易であり、かつ、第３面部６３が第１切欠部１ａに比して狭幅であるので装着が容易である等の点で、好適な形態である。
【００２３】
なお、上記実施形態に示す接続構造は、サブフレーム１０（図７）の前方側の横桁２と一対の主桁１との交差部に採用したが、後方側の横桁２と主桁１との交差部にも採用することができる。
【００２４】
【発明の効果】
以上のように構成された本発明は以下の効果を奏する。
請求項１の三転ダンプカーのサブフレーム構造によれば、横桁固定用部材の第１面部及び第３面部は、横桁に対して直交交差の関係になるとともに、第１〜第３面部は、主桁に対して重ね合わせの関係になり、部材端面同士の突き合わせ状態は存在しないので、溶接が容易であるとともに、確実な溶接が可能である。一方、第２面部は主桁上面部の内面に当接して第２切欠部を塞ぐため、横桁固定用部材は主桁の上面より上方に突出することはない。また、主桁上面側での溶接は横桁固定用部材の上面と第２切欠部の端面との間で行われるので、溶接による肉盛りの突起が主桁の上面には形成されない。従って、主桁の上面に受け木を安定して配置することができる。
【００２５】
請求項２の三転ダンプカーのサブフレーム構造によれば、「台形」を基本的形態とする部材の単純な折り曲げによって所定の形態の横桁固定用部材が構成されるため、製造が容易である。
【００２６】
請求項３の三転ダンプカーのサブフレーム構造によれば、第１面部が第１切欠部を完全に塞ぎ、実質的に隙間が生じないので、隙間の縁辺部への応力集中による亀裂の発生等を排除することができる。
【図面の簡単な説明】
【図１】本発明の一実施形態による三転ダンプカーのサブフレーム構造における要部の斜視図であり、補助ブラケットの取付途中の状態を示す。
【図２】補助ブラケット取付前の上記要部の斜視図である。
【図３】補助ブラケット取付後の上記要部の斜視図である。
【図４】溶接状態を示す上記要部の斜視図である。
【図５】上記要部に係る主桁の側面図である。
【図６】上記要部に係る補助ブラケットの展開図及び斜視図である。
【図７】上記要部を含む、サブフレーム構造全体の平面図である。
【図８】図７におけるＶＩＩＩ−ＶＩＩＩ線断面図である。
【図９】本発明との比較のために、一部構造を変えて示した上記要部の斜視図である。
【図１０】従来のサブフレーム構造における要部の斜視図である。
【符号の説明】
１主桁
１ａ第１切欠部
１ａ１、１ａ２切欠部
１ｂ上面部
１ｃ第２切欠部
１ｄ第３切欠部
１ｅ一側面部
１ｆ他側面部
２横桁
６補助ブラケット
６１第１面部
６２第２面部
６３第３面部[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a subframe structure provided on a floor surface of a vehicle body under a cargo box in a three-turn dump truck capable of selectively dumping the cargo box rearward and on both sides.
[0002]
[Prior art]
In general, a three-turn dump truck needs to be provided with hinge devices at four locations on the front, rear, left, and right sides between a cargo box and a vehicle body as disclosed in, for example, Japanese Patent Laid-Open No. 9-226438. A structural member called a subframe is provided on the floor portion.
The sub-frame is formed in a cross-girder shape with a pair of main girders whose longitudinal direction is the longitudinal direction of the vehicle and a pair of horizontal girders which intersects the main girder perpendicularly with the width direction of the vehicle as the longitudinal direction. Devices are provided at both ends of each cross beam. In order to make the floor position of the dump truck as low as possible, the crossing between the main girder and the horizontal girder was not simply overlapped, but was inserted into the hole formed in the main girder or formed in the main girder A structure in which a cross beam is inserted into the notch from above is required. However, the structure in which the cross beam is inserted into the hole formed in the main beam has problems that it is not easy to weld the main beam and the horizontal beam or the work efficiency is deteriorated. A structure is adopted in which the horizontal beam is inserted into the notch formed in the main beam from above.
[0003]
FIG. 10 is a perspective view showing an example of a conventional subframe structure in which a cross beam 102 is inserted from above into a notch 101 a formed in the main beam 101. In this case, after inserting the cross beam 102, the auxiliary bracket 103 for fixing the cross beam is attached to the notch 101a, and this auxiliary bracket 103, the main beam 101, and the horizontal beam 102 are welded together, thereby the main beam 101 and the horizontal beam 102 are welded. The digits 102 are fixed to each other.
[0004]
[Problems to be solved by the invention]
However, in the subframe structure of the conventional three-wheel dump truck as described above, the auxiliary bracket 103 and the main girder 101 must be welded (butt welding) in a state where the end surfaces are butted against each other. The operation is generally not easy due to the dimensional error of both members. Therefore, it has been difficult to perform reliable welding.
On the other hand, if the end faces are welded in a state where the ends are not aligned at the same level, the auxiliary bracket 103 may protrude above the upper surface of the main girder 101. Further, a weld overlay is formed on the upper surface of the main girder 101 to constitute a protrusion. In such a case, a receiving box mounting tray (not shown) placed on the upper surface of the main beam 101 is not stable.
[0005]
In view of the above-described conventional problems, the present invention provides a three-turn dump truck that has no protrusions or protrusions on the upper surface of the main girder and can be reliably welded at the intersection of the main girder and the horizontal girder. An object of the present invention is to provide a subframe structure.
[0006]
[Means for Solving the Problems]
The sub-frame structure of the three-turn dump truck of the present invention is a box-shaped member having a substantially rectangular cross section orthogonal to the longitudinal direction, and is formed continuously on one side, the top, and the other side, respectively. A main girder having a first notch part, a second notch part and a third notch part, and (2) inserted in a crossed state from the second notch part side to the main girder with the direction orthogonal to the main girder as a longitudinal direction. A cross beam disposed through a predetermined region in the first cutout and the third cutout, and (3) a residual opening region of the first cutout through which the crossbeam passes. A first surface portion that has a wide surface region and contacts the outer surface of one side surface portion of the main girder to block the remaining opening region, and has a width equal to or smaller than the opening width of the first notch portion perpendicular to the first surface portion. Formed and has a surface area wider than the opening area of the second notch, and is within the upper surface of the main girder. A second surface portion that abuts against the opening region of the second cutout portion, and a third cutout portion that is formed in parallel to the first surface portion perpendicular to the second surface portion and through which the cross beam passes. A surface area that is wider than the remaining opening area and corresponds to the area of the remaining opening area of the first notch, and is in contact with the inner surface of the other side surface of the main girder to form the remaining opening area of the third notch A cross girder fixing member comprising a third surface portion to be closed and welded along a boundary line between the main girder and the cross girder is provided (Claim 1).
[0007]
In the sub-frame structure of the three-wheel dump truck configured as described above, the first to third surface portions of the cross beam fixing member abut against the inner surface or the outer surface of the main beam, respectively, and the horizontal beam crosses the main beam. The opening area | region of the 1st-3rd notch part in the done state is plugged up. Accordingly, the first surface portion and the third surface portion of the cross beam fixing member are orthogonally crossed with respect to the horizontal beam, and the first to third surface portions are overlapped with the main beam. There is no abutting state between the end faces of the members. On the other hand, since the second surface portion abuts against the inner surface of the upper surface portion of the main girder and closes the second notch portion, a step is formed and the upper surface of the second surface portion is always lower than the upper surface of the main beam. Further, a corner portion formed by the upper surface of the cross beam fixing member and the end surface of the second notch is a welded portion on the upper surface side of the main beam.
[0008]
In the sub-frame structure (Claim 1), the cross beam fixing member has a developed shape in which a notch for inserting the cross beam inwardly from the upper and lower bases of the trapezoidal plate-like material is formed. The first surface portion, the second surface portion, and the third surface portion may be configured in order from the lower bottom side by bending in a U-shape along two lines parallel to the upper base or the lower base. ).
In this case, the cross beam fixing member has a shape in which the width gradually decreases from the lower bottom side of the first surface portion. The portion of the width change in the first surface portion becomes a “contact margin” to the outer surface of the main girder.
[0009]
In the subframe structure (Claim 1), the minimum width of the first surface portion may substantially coincide with the corresponding opening width of the first notch (Claim 3).
In this case, the first surface portion completely closes the first notch and substantially no gap is generated.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1-8 is a figure regarding the sub-frame structure of the three turn dump truck by one Embodiment of this invention. In addition, each figure has shown and limited to the member required for description of this invention among subframe structures, and has abbreviate | omitted illustration about the other structural member.
First, the overall structure of the subframe will be described with reference to FIGS. FIG. 7 is a plan view of the subframe 10, and FIG. 8 is a view as seen from the cross section taken along line VIII-VIII in FIG. The left side of each figure corresponds to the front of the vehicle body (not shown) and the right side corresponds to the rear. In FIG. 7, the pair of main girders 1 are box-shaped members that are provided parallel to each other with the longitudinal direction of the vehicle body as the longitudinal direction, and whose cross-sectional shape orthogonal to the longitudinal direction is substantially rectangular.
[0011]
On the other hand, the pair of transverse girders 2 are pipe-like members, and are arranged orthogonally intersecting with the main girders 1 with the width direction of the vehicle body as the longitudinal direction. The main beam 1 and the horizontal beam 2 are welded to each other at four points where they intersect. In addition, hinge devices 4 are attached to both ends of each cross beam 2. A rotating shaft 3 is supported around the axis of the rear side beam 2 so as to be rotatable with respect to the beam 2, and a part of the hinge device 4 is connected to the rotating shaft 3. A cross member 5 is attached between the front end portions of the main beam 1.
When dumping a dump truck's packing box (not shown) backward, the front hinge device 4 is unlocked, and the packing box tilts with the rotary shaft 3 as a support shaft. When dumping the packing box to the side, the pair of left and right hinge devices 4 are unlocked, and the packing box tilts with the other pair of hinge devices 4 as a fulcrum.
Next, the connection structure at the intersection of the front side beam 2 and the main beam 1 will be described in detail.
[0012]
1 to 4 are perspective views showing a connection structure at an intersection (a portion indicated by a symbol X in FIG. 7) between the main beam 1 and the horizontal beam 2, and FIG. 1 is a state in the middle of attachment of an auxiliary bracket 6 described later. 2 shows a state before the auxiliary bracket is attached, FIG. 3 shows a state after the auxiliary bracket 6 is attached, and FIG. 4 further shows a state after welding. Moreover, (a) and (b) of FIG. 5 are the A arrow side view and B arrow side view of FIG. 2 about only the main girder 1 in a cross | intersection part, respectively.
[0013]
In FIG. 5 (a), on one side surface of the main beam 1, a notch 1a1 forming a rectangular opening having a width W1 and a height H, and a semicircle having a diameter W2 (<W1) downward from the central portion thereof. The 1st notch part 1a which consists of the notch part 1a2 which forms a shape-like opening is provided. Further, the upper surface portion 1b of the main beam 1 is provided with a second cutout portion 1c that is continuous with the first cutout portion 1a and forms a rectangular opening having a width W2. On the other hand, as shown in (b), a third cutout portion 1d that forms a U-shaped opening is provided on the other side surface portion of the main beam 1 so as to be continuous with the second cutout portion 1c. The width of the third cutout 1d and the diameter of the bottom semicircle are W2. The value of W2 is obtained by adding a very small clearance to the outer diameter of the cross beam 2. According to the notch configuration as described above, the opening area of the third notch portion 1d is in a range corresponding to the opening area of the first notch portion 1a, and the opening width of the second notch portion 1c is The relationship is equal to or smaller than the opening width of the one notch 1a.
[0014]
FIG. 2 shows a state in which a transverse beam 2 is arranged orthogonally intersecting with the main beam 1 having the first to third notches 1a, 1c and 1d as described above. As described above, since the width W2 of the second notch portion 1c and the third notch portion 1d is slightly larger than the outer diameter of the transverse beam 2, the transverse beam 2 is inserted across the main beam 1, and the notch portion 1a2 and the It will be in the state which touched the lower circular arc part of 3 notch part 1d.
[0015]
Next, as shown in FIG. 1, the auxiliary bracket 6 is attached. Here, the auxiliary bracket 6 is a cross beam fixing member, and has a developed shape shown in FIG. 6A before bending. Further, after the bending process, the shape shown in FIG. As shown in (a) and (b), the auxiliary bracket 6 has U-shaped cutouts 6a and 6b provided inward from the lower and upper bases of the trapezoidal steel plate, respectively. Are bent at right angles along the dotted lines L1 and L2 to form a substantially “U” shape. The auxiliary bracket 6 after the bending process has a first surface portion 61 having a notch portion 6a, a second surface portion 62 orthogonal to the first surface portion 61, and a notch portion 6b, as shown in FIG. A third surface portion 63 orthogonal to the second surface portion 62 and parallel to the first surface portion 61 is provided. The width of the notches 6a and 6b and the diameter of each arc portion are the same as the width W2. The width W1 of the portion bent at the dotted line L1 is equal to the width W1 of the notch 1a1 shown in FIG. 5 (in practice, it may be a value slightly smaller than the value of the width W1 of the notch 1a1 in consideration of manufacturing errors). .) The width W3 of the portion bent at the dotted line L2 is smaller than the width W1 and larger than the width W2. Further, the width W4 of the lower end of the first surface portion 61 is larger than the width W1. That is, each width has a relationship of W4>W1>W3> W2.
[0016]
In FIG. 6B, the thickness of the auxiliary bracket 6 is t1, the depth (external method) of the second surface portion 62 is D1, the plate thickness of the main girder 1 in FIG. 2 is t2, and the depth (external method) is D2. Then, D1-t1 = D2-t2. Therefore, when the plate thicknesses t1 and t2 are the same, D1 = D2.
Moreover, the height H of the 3rd surface part 63 of the auxiliary | assistant bracket 6 shown to (b) of FIG. 6 is equivalent to the height H of the notch part 1a1 in (a) of FIG.
[0017]
As shown in FIG. 1, the auxiliary bracket 6 having the above-described configuration is mounted from the side surface of the main beam 1 on the side where the notch portion 1 a 1 is provided. At this time, as described above, the maximum width (W3) of the third surface portion 63 of the auxiliary bracket 6 is smaller than the width (W1) of the notch portion 1a1, and the height (H) of the third surface portion 63 is notch portion 1a1. Is equal to the height of Further, the first surface portion 61 and the third surface portion 63 are provided with notches 6a and 6b that match the outer diameter of the cross beam 2 (FIG. 6). Accordingly, the third surface portion 63 can pass through the remaining opening region excluding the region where the cross beam 2 is inserted in the opening region of the first cutout portion 1a. And the state which pushed in the auxiliary | assistant bracket 6 to the axial direction of the cross beam 2 is shown in FIG.
[0018]
1 and 3, the minimum width W1 of the first surface portion 61 of the auxiliary bracket 6 is equal to the width of the notch portion 1a1, and the maximum width W4 is larger than the width of the notch portion 1a1, so the inner surface of the first surface portion 61 is Abutting on the outer surface of one side surface portion 1e (near side) of the main girder 1, the remaining opening region except the region where the horizontal beam 2 is inserted in the cutout portion 1a1 is closed. Further, since the width of the second surface portion 62 (W3 or more and W1 or less) is larger than the width W2 of the second notch portion 1c, the upper surface of the second surface portion 62 abuts on the inner surface of the upper surface portion 1b of the main girder 1 and is second. The opening area of the notch 1c is closed. Further, since the width of the third surface portion 63 (greater than W2 and less than or equal to W3) is larger than the width W2 of the third notch portion 1d, the outer surface of the third surface portion 63 abuts against the inner surface of the other side surface portion 1f of the main girder 1. In contact therewith, the remaining opening area except the area where the cross beam 2 is inserted in the third cutout 1d is closed. In this case, the first surface portion 61 and the third surface portion 63 contact the outer surface of the one side surface portion 1e of the main girder 1 and the inner surface of the other side surface portion 1f without any gaps by the above-described relationship of D1-t1 = D2-t2. Touch.
[0019]
As a result, the auxiliary bracket 6 is in contact with both side surface portions and the upper surface portion of the main girder 1 so as to overlap each other, and there is no abutting state between the member end surfaces. Further, since the second surface portion 62 abuts on the inner surface of the upper surface portion 1b of the main girder 1 and closes the opening area of the second notch portion 1c, a step is formed so that the upper surface of the second surface portion 62 is higher than the upper surface of the main beam 1. Always in a low position. Therefore, the auxiliary bracket 6 cannot protrude upward from the upper surface of the main beam 1.
[0020]
Thereafter, as shown in (a) of FIG. 4 and a perspective view as viewed from the back side of (a), welding is continuously performed at the corners along the contact line boundary line between the members (welding). The main beam 1 and the auxiliary bracket 6 are fixed, and the auxiliary bracket 6 and the horizontal beam 2 are fixed respectively. Since there is no butt welding portion between the member end faces in the welded portion, welding is easy and reliable welding can be performed.
On the other hand, the welding on the upper surface side of the main girder 1 is a corner formed by the upper surface of the auxiliary bracket 6 having a level difference from the upper surface of the main girder 1 and the end surface (thickness portion) of the second notch 1c. Done in Therefore, the upward protrusion of the build-up due to welding is absorbed in the step, and the build-up can be prevented from protruding upward from the upper surface of the main girder 1.
[0021]
Apart from the above embodiment, if the width of the upper end side of the first surface portion 61 of the auxiliary bracket 6 is smaller than the width of the notch 1a1 of the main girder 1, as shown in FIG. A gap G is formed at the time of attachment, and stress concentration occurs at the welded portions at the left and right end portions of the first surface portion 61. As a result, the auxiliary bracket 6 is likely to crack from the portion indicated by the point P. However, in the above embodiment, the width W1 on the upper end side of the first surface portion 61 of the auxiliary bracket 6 matches the width of the notch portion 1a1 of the main girder 1, so that the entire left and right end portions of the first surface portion 61 are Welded to distribute stress evenly. Therefore, the occurrence of cracks as described above can be prevented.
[0022]
In the above embodiment, the auxiliary bracket 6 has a trapezoidal basic shape as shown in FIG. 6, but the present invention is not limited to this, and various forms are possible. For example, the second surface portion 62 and the third surface portion 63 may have the same width, or only the second surface portion 62 may have the same width. Moreover, the 1st surface part 61 may be the same width | variety wider than an other surface part. However, the auxiliary bracket 6 of the present embodiment having a trapezoidal shape as a basic form has a small material area, is easy to manufacture, and the third surface portion 63 is narrower than the first cutout portion 1a. This is a preferable form in terms of easy mounting.
[0023]
In addition, although the connection structure shown in the said embodiment was employ | adopted at the cross | intersection part of the cross beam 2 of the front side of the sub-frame 10 (FIG. 7) and a pair of main beam 1, the back beam 2 and the main beam 1 of the back side are employ | adopted. It can also be used at intersections.
[0024]
【The invention's effect】
The present invention configured as described above has the following effects.
According to the sub-frame structure of the three-turn dump truck of claim 1, the first surface portion and the third surface portion of the cross beam fixing member are orthogonally crossed with respect to the cross beam, and the first to third surface portions are Since the main girder is superposed and there is no abutting state between the end surfaces of the members, welding is easy and reliable welding is possible. On the other hand, since the second surface portion abuts against the inner surface of the main girder upper surface portion and closes the second notch portion, the cross beam fixing member does not protrude above the upper surface of the main girder. Further, since the welding on the upper surface side of the main girder is performed between the upper surface of the cross beam fixing member and the end surface of the second notch portion, the build-up protrusion due to welding is not formed on the upper surface of the main beam. Therefore, it is possible to stably place the receiving tree on the upper surface of the main girder.
[0025]
According to the sub-frame structure of the tri-turn dump truck of claim 2, since the member for fixing the cross beam in a predetermined form is configured by simple bending of the member having a basic shape of “trapezoid”, the manufacture is easy. .
[0026]
According to the sub-frame structure of the three-wheeled dump truck of claim 3, the first surface portion completely covers the first notch and substantially no gap is generated, and therefore, cracks are generated due to stress concentration on the edge of the gap. Can be eliminated.
[Brief description of the drawings]
FIG. 1 is a perspective view of a main part of a sub-frame structure of a three-turn dump truck according to an embodiment of the present invention, showing a state in the middle of attachment of an auxiliary bracket.
FIG. 2 is a perspective view of the main part before the auxiliary bracket is attached.
FIG. 3 is a perspective view of the main part after the auxiliary bracket is attached.
FIG. 4 is a perspective view of the main part showing a welded state.
FIG. 5 is a side view of a main girder according to the main part.
FIG. 6 is a development view and a perspective view of an auxiliary bracket according to the main part.
FIG. 7 is a plan view of the entire subframe structure including the main part.
8 is a cross-sectional view taken along line VIII-VIII in FIG.
FIG. 9 is a perspective view of the main part shown with a part of the structure changed for comparison with the present invention.
FIG. 10 is a perspective view of a main part in a conventional subframe structure.
[Explanation of symbols]
1 main girder 1a first cutout portion 1a1, 1a2 cutout portion 1b upper surface portion 1c second cutout portion 1d third cutout portion 1e one side surface portion 1f other side surface portion 2 cross beam 6 auxiliary bracket 61 first surface portion 62 second surface portion 63 first 3 sides

Claims

長手方向に直交する断面が略矩形のボックス状部材であって、一側面部、上面部及び他側面部に連続してそれぞれ形成された第１切欠部、第２切欠部及び第３切欠部を有する主桁と、
前記主桁と直交する方向を長手方向として前記第２切欠部側から前記主桁に交差状態で挿入される部材であって、前記第１切欠部内及び前記第３切欠部内の所定領域を通過して配置された横桁と、
前記横桁が通過した前記第１切欠部の残余開口領域より広い面領域を有し、前記主桁の一側面部の外面に当接して前記残余開口領域を塞ぐ第１面部、この第１面部と直交して前記第１切欠部の開口幅以下の幅で形成され、前記第２切欠部の開口領域より広い面領域を有し、前記主桁の上面部の内面に当接して前記第２切欠部の開口領域を塞ぐ第２面部、及び、この第２面部と直交して前記第１面部に平行に形成され、前記横桁が通過した前記第３切欠部の残余開口領域より広く且つ前記第１切欠部の残余開口領域の範囲内に相当する面領域を有し、前記主桁の他側面部の内面に当接して前記第３切欠部の残余開口領域を塞ぐ第３面部を有して成り、前記主桁及び横桁との当接部境界線に沿って溶接された横桁固定用部材と
を備えたことを特徴とする三転ダンプカーのサブフレーム構造。A box-shaped member having a substantially rectangular cross-section perpendicular to the longitudinal direction, the first notch, the second notch, and the third notch formed continuously from the one side, the top, and the other side, respectively. A main girder with
A member that is inserted from the second cutout side into the main girder in a crossed state with a direction orthogonal to the main girder as a longitudinal direction, and passes through predetermined regions in the first cutout and the third cutout. And a cross beam arranged
A first surface portion having a surface area wider than a residual opening region of the first notch portion through which the cross beam passes, and abutting against an outer surface of one side surface portion of the main girder to block the residual opening region, the first surface portion Is formed with a width equal to or smaller than the opening width of the first notch, has a surface area wider than the opening area of the second notch, and abuts against the inner surface of the upper surface of the main girder. A second surface portion that closes the opening region of the notch, and a portion that is formed in parallel to the first surface portion perpendicular to the second surface portion, and wider than the remaining opening region of the third notch portion through which the cross beam passes and A surface region corresponding to the range of the remaining opening region of the first notch, and a third surface portion that contacts the inner surface of the other side surface of the main girder and closes the remaining opening region of the third notch. And a cross beam fixing member welded along a boundary line between the main girder and the cross beam. Three rolling dump truck of the sub-frame structure.

前記横桁固定用部材は、台形板状材の上底及び下底から内方にそれぞれ前記横桁を挿通させるための切欠部を形成した展開形状であって、上底又は下底に平行な２本の線に沿ってコの字状に折り曲げることにより下底側から順に前記第１面部、第２面部及び第３面部が構成されていることを特徴とする請求項１記載の三転ダンプカーのサブフレーム構造。The cross beam fixing member has a developed shape in which a notch for inserting the cross beam is inserted inward from the upper and lower bases of the trapezoidal plate-like material, and is parallel to the upper or lower base. 2. The three-wheeled dump truck according to claim 1, wherein the first surface portion, the second surface portion, and the third surface portion are formed in order from the lower bottom side by bending in a U-shape along two lines. Subframe structure.

前記第１面部の最小幅が、前記第１切欠部の対応する開口幅と略一致していることを特徴とする請求項１記載の三転ダンプカーのサブフレーム構造。2. The sub-frame structure of a three-turn dump truck according to claim 1, wherein a minimum width of the first surface portion substantially coincides with a corresponding opening width of the first notch portion.