JP3683751B2

JP3683751B2 - Track frame of swivel construction machine

Info

Publication number: JP3683751B2
Application number: JP25083099A
Authority: JP
Inventors: 勝弥田上
Original assignee: Hitachi Construction Machinery Co Ltd
Current assignee: Hitachi Construction Machinery Co Ltd
Priority date: 1999-09-03
Filing date: 1999-09-03
Publication date: 2005-08-17
Anticipated expiration: 2019-09-03
Also published as: JP2001073409A

Description

【０００１】
【発明の属する技術分野】
本発明は、例えば油圧ショベル、油圧クレーン等の下部走行体を構成する旋回式建設機械のトラックフレームに関する。
【０００２】
【従来の技術】
一般に、油圧ショベル等の旋回式建設機械は、下部走行体と、該下部走行体上に旋回可能に搭載された上部旋回体と、該上部旋回体の前部側に俯仰動可能に設けられた作業装置とにより大略構成されている。
【０００３】
そこで、この種の従来技術による旋回式建設機械として大型の油圧ショベルを例に挙げ、図８ないし図１１を参照して説明する。
【０００４】
図において、１は下部走行体、２は下部走行体１上に旋回装置３を介して旋回可能に設けられた上部旋回体で、該上部旋回体２は、旋回フレーム４、該旋回フレーム４上に配設されたキャブ５、建屋カバー６、カウンタウエイト７等により構成されている。そして、上部旋回体２の前部側には作業装置（図示せず）が俯仰動可能に設けられる構成となっている。
【０００５】
１１は下部走行体１を構成するトラックフレームで、該トラックフレーム１１は、図９ないし図１１に示すように、後述のセンタフレーム１２と、丸胴２０と、サイドフレーム２６とにより大略構成されている。
【０００６】
１２はトラックフレーム１１の中央部を構成するセンタフレームで、該センタフレーム１２は、全体としてほぼＨ型状をなし、左，右方向の両端側には前，後に離間して合計４個の脚部１２Ａ，１２Ａ，…が設けられている。
【０００７】
ここで、センタフレーム１２は、鋼板等によりほぼＨ型状に形成された下板１３と、該下板１３の上面側に立設された鋼板等からなる複数の中板１４，１４，…と、丸胴２０と下板１３との間に設けられ丸胴２０を下側から支持する円筒状中板１５と、丸胴２０の内周側に設けられ下板１３と対面する環状板１６と、下板１３と対面するように各中板１４の上端側に固着された後述の上板１７とにより、強固な骨組構造をもって形成されている。
【０００８】
１７は下板１３、各中板１４、円筒状中板１５、環状板１６等と共にセンタフレーム１２を構成する上板で、該上板１７は、丸胴２０の中心Ｏを通る前，後方向の仮想線Ａ−Ａを境としてほぼ同一形状を有する左上板１８と右上板１９とにより構成されている。ここで、各上板１８，１９の前，後方向の長さ寸法は、素材となる鋼板材をできるだけ小さくして材料費を低減するため、丸胴２０の外径寸法とほぼ等しい寸法に設定され、各上板１８，１９には、丸胴２０の中心Ｏを中心として１８０度未満の角度をもった円弧部１８Ａ，１９Ａがそれぞれ形成されている。
【０００９】
２０はセンタフレーム１２を構成する上板１７の上面側中央部に設けられた丸胴で、該丸胴２０は大径の円筒状に形成されている。そして、丸胴２０の下端側外周は、左上板１８の円弧部１８Ａと右上板１９の円弧部１９Ａとにそれぞれ溶接され、左上板１８と丸胴２０との間には円弧状の溶接部２１が形成され、右上板１９と丸胴２０との間には円弧状の溶接部２２が形成されている。また、丸胴２０の上端側には、多数のねじ穴２０Ａ，２０Ａ，…が周方向に一定間隔をもって形成され、後述の旋回輪２３が取付けられる構成となっている。
【００１０】
２３は丸胴２０の上端側に取付けられた旋回輪で、該旋回輪２３は、内輪２３Ａおよび該内輪２３Ａに対して回転可能となった外輪２３Ｂ等からなり、旋回モータ（図示せず）等と共に旋回装置３を構成するものである。そして、旋回輪２３の内輪２３Ａは、丸胴２０の上端面にボルト２４によって取付けられ、外輪２３Ｂは、上部旋回体２側の旋回フレーム４にボルト２５によって取付けられている。
【００１１】
２６，２６はセンタフレーム１２の左，右両側に配設された左，右のサイドフレームで、該各サイドフレーム２６は、センタフレーム１２の各脚部１２Ａ先端側にブラケット２７を介して取付けられ、前，後方向に伸長している。そして、サイドフレーム２６の後端側には駆動輪２８が設けられ、サイドフレーム２６の前端側には遊動輪２９が設けられ、駆動輪２８と遊動輪２９との間には履帯３０が巻回されている。
【００１２】
従来技術による油圧ショベルは上述の如き構成を有するもので、下部走行体１のトラックフレーム１１は、丸胴２０、旋回輪２３等を介して上部旋回体２の自重、土砂等の掘削作業時における作業装置からの掘削反力等を受ける。
【００１３】
【発明が解決しようとする課題】
ところで、上述した従来技術によるトラックフレーム１１は、上板１７を左上板１８と右上板１９とにより構成し、これら各上板１８，１９と丸胴２０の外周側との間を、円弧状の溶接部２１，２２の範囲で溶接を施すことによって固着する構成となっている。
【００１４】
このため、左上板１８および右上板１９と丸胴２０の外周側との間に全周に亘る溶接（全周溶接）を施すことができず、図１０および図１１に示すように、丸胴２０の外周側のうち、各上板１８，１９間に位置する部位には溶接が施されていない。従って、従来技術によるトラックフレーム１１は、左上板１８と丸胴２０との間と右上板１９と丸胴２０との間とで、少なくとも２回の溶接作業が必要となり、この溶接作業の作業性が低下してしまうという問題がある。
【００１５】
また、左上板１８と丸胴２０との間を溶接することにより、両者間に円弧状の溶接部２１を形成した後には、この溶接部２１の前端部２１Ａと後端部２１Ｂの表面をグラインダ等を用いて研削する表面仕上げを行う必要がある。そして、この表面仕上げ作業は、右上板１９と丸胴２０との間に形成された溶接部２２の前端部２２Ａと後端部２２Ｂの表面にも行う必要があるため、合計４回の表面仕上げ作業を行うこととなり、この表面仕上げ作業に多大な時間を費やしてしまうという問題がある。
【００１６】
さらに、左上板１８と丸胴２０との間に形成される溶接部２１の形状と、右上板１９と丸胴２０との間に形成される溶接部２２の形状とが均一化せず、各上板１８，１９と丸胴２０との間の溶接部の品質がばらついてしまうという問題がある。
【００１７】
本発明は上述した従来技術の問題に鑑みなされたもので、センタフレームの上板と丸胴との間を溶接するときの作業性を向上することができるようにした旋回式建設機械のトラックフレームを提供することを目的としている。
【００１８】
【課題を解決するための手段】
上述した課題を解決するために本発明は、全体としてほぼＨ型状をなし左，右方向の両端に前，後の脚部を有するセンタフレームと、該センタフレームの上面側中央部に設けられた丸胴と、前記センタフレームの左，右両側に位置して前記脚部に取付けられた左，右のサイドフレームとからなり、前記丸胴は下端側外周にフランジ部が一体形成されたフランジ付きの円筒体により構成してなる旋回式建設機械のトラックフレームに適用される。
【００１９】
そして、請求項１の発明が採用する構成の特徴は、前記センタフレームは、下板と、該下板上に複数の中板を介して設けられ前記丸胴のフランジ部が溶接される左上板，右上板とにより構成し、前記左上板，右上板間には、前記丸胴の前側となる位置で前記丸胴のフランジ部外周を跨いで前記左上板，右上板間の前側部位を継ぐ前帯板と、前記丸胴の後側となる位置で前記丸胴のフランジ部外周を跨いで前記左上板，右上板間の後側部位を継ぐ後帯板とを設け、前記丸胴のフランジ部は、その外周側を前記左上板、右上板、前帯板および後帯板からなる４枚の板に対し全周に亘って溶接する構成としたことにある。
【００２０】
このように構成したことにより、センタフレームの上板と丸胴のフランジ部との間を溶接するときに、前記フランジ部の外周側を左上板，右上板と前帯板，後帯板とに全周に亘って溶接することができる。このため、上板と丸胴のフランジ部との間を１回の溶接作業によって全周溶接することができ、このときの作業性を向上することができる。また、左上板，右上板および前帯板，後帯板と丸胴のフランジ部との間には、前端部と後端部のない環状（無端状）の溶接部が形成されるので、溶接部の前端部と後端部に対する煩わしい表面仕上げ作業を不要にできる。
【００２１】
請求項２の発明が採用する構成の特徴によると、前記センタフレームは、下板と、該下板上に複数の中板を介して設けられ前記丸胴のフランジ部が溶接される前上板，後上板とにより構成し、前記前上板，後上板間には、前記丸胴の左側となる位置で前記丸胴のフランジ部外周を跨いで前記前上板，後上板間の左側部位を継ぐ左帯板と、前記丸胴の右側となる位置で前記丸胴のフランジ部外周を跨いで前記前上板，後上板間の右側部位を継ぐ右帯板とを設け、前記丸胴のフランジ部は、その外周側を前記前上板、後上板、左帯板および右帯板からなる４枚の板に対し全周に亘って溶接する構成としたことにある。
【００２２】
このように構成したことにより、センタフレームの前上板，後上板および該各上板間を継ぐ左帯板，右帯板と丸胴のフランジ部外周との間を１回の溶接作業によって全周溶接することができ、このときの作業性を向上することができる。
【００２３】
請求項３の発明が採用する構成の特徴によると、前記センタフレームは、下板と、該下板上に複数の中板を介して設けられ前記丸胴のフランジ部が溶接される左前上板，右前上板，左後上板，右後上板からなる４枚の上板とにより構成し、前記左前上板と右前上板との間には、前記丸胴の前側となる位置で前記丸胴のフランジ部外周を跨いで前記左前上板と右前上板との前側部位を継ぐ前帯板を設け、前記左後上板と右後上板との間には、前記丸胴の後側となる位置で前記丸胴のフランジ部外周を跨いで前記左後上板と右後上板との後側部位を継ぐ後帯板を設け、前記左前上板と左後上板との間には、前記丸胴の左側となる位置で前記丸胴のフランジ部外周を跨いで前記左前上板と左後上板との間を継ぐ左帯板を設け、前記右前上板と右後上板との間には、前記丸胴の右側となる位置で前記丸胴のフランジ部外周を跨いで前記右前上板と右後上板との間を継ぐ右帯板を設け、前記丸胴のフランジ部は、その外周側を前記左前上板，右前上板，左後上板，右後上板からなる４枚の上板と、前記前帯板，後帯板，左帯板，右帯板からなる４枚の帯板との８枚の板に対し全周に亘って溶接する構成としたことにある。
【００２４】
このように構成したことにより、センタフレームの上板と丸胴のフランジ部との間を溶接するときに、前記フランジ部の外周側を左前上板，右前上板，左後上板，右後上板からなる４枚の上板と、前帯板，後帯板，左帯板，右帯板からなる４枚の帯板とに全周に亘って溶接することができる。このため、上板と丸胴のフランジ部との間に１回の溶接作業によって全周溶接を施すことができ、このときの作業性を向上することができる。
【００２５】
しかも、上板を左前上板，右前上板，左後上板，右後上板の４枚によって構成することにより、１枚の上板（左前上板，右前上板，左後上板，右後上板）の面積を小さくできるので、例えば素材となる板材から各上板を無駄なく切断することができ、材料費の低減にも寄与することができる。
【００２６】
【発明の実施の形態】
以下、本発明による旋回式建設機械のトラックフレームの実施の形態を、大型の油圧ショベルのトラックフレームを例に挙げ、図１ないし図７を参照しつつ説明する。まず、図１ないし図３は本発明による第１の実施の形態を示している。なお、本実施の形態では上述した従来技術と同一の構成要素に同一符号を付し、その説明を省略するものとする。
【００２７】
図１において、３１は従来技術によるトラックフレーム１１に代えて本実施の形態に適用したトラックフレームで、該トラックフレーム３１は、従来技術によるトラックフレーム１１とほぼ同様に、後述のセンタフレーム３２と、丸胴３６と、サイドフレーム２６とにより大略構成されている。
【００２８】
３２はトラックフレーム３１の中央部を構成するセンタフレームで、該センタフレーム３２は、全体としてほぼＨ型状をなし、左，右方向の両端側には前，後に離間して合計４個の脚部３２Ａ，３２Ａ，…が設けられ、該各脚部３２Ａの先端側には、ブラケット２７を介してサイドフレーム２６が取付けられている。
【００２９】
そして、センタフレーム３２は、下板１３と、該下板１３の上面側に立設された複数の中板１４，１４，…と、丸胴３６と下板１３との間に設けられた円筒状中板１５と、丸胴３６の内周側に設けられた環状板１６と、下板１３と対面するように各中板１４の上端側に固着された後述の上板３３等とより、強固な骨組構造をもって形成されている。
【００３０】
３３はセンタフレーム３２を構成する上板で、該上板３３は、従来技術のものと同様に、丸胴３６の中心Ｏ１を通る前，後方向の仮想線Ａ１−Ａ１を境としてほぼ同一形状を有する左上板３４と右上板３５とにより構成されている。ここで、各上板３４，３５の前，後方向の長さ寸法は、素材となる鋼板材をできるだけ小さくして材料費を低減するため、丸胴３６の外径寸法とほぼ等しい寸法に設定されている。そして、左上板３４には、丸胴３６の中心Ｏ１を中心として１８０度未満の角度をもった円弧部３４Ａが形成され、右上板３５にも、丸胴３６の中心Ｏ１を中心として１８０度未満の角度をもった円弧部３５Ａが形成されている。
【００３１】
３６は従来技術による丸胴２０に代えて本実施の形態に適用した丸胴で、該丸胴３６は、円筒部３６Ａと、該円筒部３６Ａの下端側に全周に亘って拡径するように一体形成されたフランジ部３６Ｂと、円筒部３６Ａとフランジ部３６Ｂとの間の角隅部に全周に亘って形成された凹湾曲部３６Ｃとにより、フランジ付きの円筒体として形成されている。また、円筒部３６Ａの上端側には、旋回輪２３の内輪２３Ａを取付けるための多数のねじ穴３６Ｄ，３６Ｄ，…が形成されている。
【００３２】
３７，３８は左上板３４と右上板３５との間を継ぐため、丸胴３６のフランジ部３６Ｂ外周を跨いで各上板３４，３５間にそれぞれ設けられた前帯板，後帯板で、これら前帯板３７，後帯板３８は、例えば各上板３４，３５とほぼ等しい肉厚をもった帯鋼により形成されている。
【００３３】
ここで、前帯板３７，後帯板３８には、丸胴３６のフランジ部３６Ｂ外周とほぼ等しい曲率をもった円弧部３７Ａ，３８Ａがそれぞれ形成され、これら円弧部３７Ａ，３８Ａの先端側には、丸胴３６のフランジ部３６Ｂとの間にＫ形開先を形成するための開先加工が施されている。
【００３４】
そして、丸胴３６のフランジ部３６Ｂ外周は、左上板３４，右上板３５の円弧部３４Ａ，３５Ａと、前帯板３７，後帯板３８の円弧部３７Ａ，３８Ａとに全周に亘って連続的に溶接（全周溶接）が施され、丸胴３６のフランジ部３６Ｂ外周側には、前端部および後端部のない環状（無端状）の溶接部３９が形成されている。
【００３５】
また、前帯板３７の長手方向の両端部と上板３４，３５との間、および後帯板３８の長手方向の両端部と上板３４，３５との間はそれぞれ突合せ溶接され、溶接部４０，４０，…が形成されている。
【００３６】
本実施の形態によるトラックフレーム３１は上述の如き構成を有するもので、その基本的作動については従来技術によるものと格別差異はない。
【００３７】
然るに、本実施の形態では、センタフレーム３２の上板３３を構成する左上板３４と右上板３５との間に２枚の帯板３７，３８を設けることにより、丸胴３６（フランジ部３６Ｂ）の外周側と、２枚の上板３４，３５の円弧部３４Ａ，３５Ａと２枚の帯板３７，３８の円弧部３７Ａ，３８Ａとの間に全周に亘って溶接を施すことができる構成となっている。
【００３８】
これにより、本実施の形態では、上板３３と丸胴３６の外周側との間の溶接作業を１回の全周溶接によって完了することができる。このため、例えば従来技術で述べたように、上板１７を構成する左上板１８と右上板１９とをそれぞれ丸胴２０の外周側に溶接することにより少なくとも２回の溶接作業が必要となる場合に比較して、溶接作業の作業性を向上することができる。
【００３９】
また、本実施の形態では、左上板３４，右上板３５および前帯板３７，後帯板３８と丸胴３６の外周側との間に、前端部と後端部のない環状の溶接部３９を形成することができる。このため、例えば従来技術で述べたような、左上板１８と丸胴２０との間に形成された溶接部２１の各端部２１Ａ，２１Ｂ、および右上板１９と丸胴２０との間に形成された溶接部２２の各端部２２Ａ，２２Ｂに対する表面仕上げ作業を不要にでき、溶接作業に要する時間を大幅に短縮することができる。
【００４０】
さらに、本実施の形態では、左上板３４，右上板３５および前帯板３７，後帯板３８と丸胴３６の外周側との間に全周に亘って溶接を施すことにより、上板３３と丸胴３６の外周側との間にほぼ均一な形状をもった環状の溶接部３９を形成することができ、この溶接部３９の品質を高めることができる。
【００４１】
次に、図４ないし図６は本発明による第２の実施の形態を示し、本実施の形態の特徴は、センタフレームの上板を４枚の上板により構成し、これら各上板間を４枚の帯板によって継ぐ構成としたことにある。なお、本実施の形態では上述した従来技術と同一の構成要素に同一符号を付し、その説明を省略するものとする。
【００４２】
図において、４１は従来技術によるトラックフレーム１１に代えて本実施の形態に適用したトラックフレームで、該トラックフレーム４１は、従来技術によるトラックフレーム１１とほぼ同様に、後述のセンタフレーム４２と、丸胴４８と、サイドフレーム２６とにより大略構成されている。
【００４３】
４２はトラックフレーム４１の中央部を構成するセンタフレームで、該センタフレーム４２は、全体としてほぼＨ型状をなし、左，右方向の両端側には前，後に離間して合計４個の脚部４２Ａ，４２Ａ，…が設けられ、該各脚部４２Ａの先端側には、ブラケット２７を介してサイドフレーム２６が取付けられている。
【００４４】
そして、センタフレーム４２は、下板１３と、該下板１３の上面側に立設された複数の中板１４，１４，…と、丸胴３６と下板１３との間に設けられた円筒状中板１５と、丸胴３６の内周側に設けられた環状板１６と、下板１３と対面するように各中板１４の上端側に固着された後述の上板４３とにより、強固な骨組構造をもって形成されている。
【００４５】
４３はセンタフレーム４２を構成する上板で、該上板４３は、丸胴４８の中心Ｏ２を通る前，後方向の仮想線Ａ２−Ａ２と左，右方向の仮想線Ｂ２−Ｂ２を境としてほぼ同一形状に形成された左前上板４４と、右前上板４５と、左後上板４６と、右後上板４７とにより構成されている。
【００４６】
ここで、左前上板４４には、丸胴４８の中心Ｏ２を中心として９０度未満の角度をもった円弧部４４Ａが形成されている。また、右前上板４５，左後上板４６，右後上板４７についても、左前上板４４と同様に、丸胴４８の中心Ｏ２を中心として９０度未満の角度をもった円弧部４５Ａ，４６Ａ，４７Ａがそれぞれ形成されている。
【００４７】
４８は従来技術による丸胴２０に代えて本実施の形態に適用した丸胴で、該丸胴４８は、円筒部４８Ａと、該円筒部４８Ａの下端側に全周に亘って拡径するように一体形成されたフランジ部４８Ｂと、円筒部４８Ａとフランジ部４８Ｂとの間の角隅部に全周に亘って形成された凹湾曲部４８Ｃとにより、フランジ付きの円筒体として形成されている。また、円筒部４８Ａの上端側には、旋回輪２３の内輪２３Ａを取付けるための多数のねじ穴４８Ｄ，４８Ｄ，…が形成されている。
【００４８】
４９は左前上板４４と右前上板４５との間に設けられた前帯板、５０は左後上板４６と右後上板４７との間に設けられた後帯板で、これら前帯板４９，後帯板５０は、例えば左前上板４４等とほぼ等しい肉厚をもった帯鋼により形成され、丸胴４８のフランジ部４８Ｂ外周を跨いで前，後方向で対をなしている。ここで、前帯板４９，後帯板５０には、丸胴４８のフランジ部４８Ｂ外周とほぼ等しい曲率をもった円弧部４９Ａ，５０Ａがそれぞれ形成され、これら円弧部４９Ａ，５０Ａの先端側には、丸胴４８のフランジ部４８Ｂとの間にＫ形開先を形成するための開先加工が施されている。
【００４９】
５１は左前上板４４と左後上板４６との間に設けられた左帯板、５２は右前上板４５と右後上板４７との間に設けられた右帯板で、これら左帯板５１，右帯板５２は、例えば左前上板４４等とほぼ等しい肉厚をもった帯鋼により形成され、丸胴４８のフランジ部４８Ｂ外周を跨いで左，右方向で対をなしている。ここで、左帯板５１，右帯板５２には、丸胴４８のフランジ部４８Ｂ外周とほぼ等しい曲率をもった円弧部５１Ａ，５２Ａがそれぞれ形成され、これら円弧部５１Ａ，５２Ａの先端側には、丸胴４８のフランジ部４８Ｂとの間にＫ形開先を形成するための開先加工が施されている。
【００５０】
そして、丸胴４８のフランジ部４８Ｂ外周と、左前上板４４，右前上板４５，左後上板４６，右後上板４７の円弧部４４Ａ，４５Ａ，４６Ａ，４７Ａと、前帯板４９，後帯板５０，左帯板５１，右帯板５２の円弧部４９Ａ，５０Ａ，５１Ａ，５２Ａとの間には、全周に亘って連続的に溶接（全周溶接）が施され、丸胴４８のフランジ部４８Ｂ外周側には、前端部および後端部のない環状（無端状）の溶接部５３が形成されている。
【００５１】
また、前帯板４９の長手方向の両端部と上板４４，４５との間、後帯板５０の両端部と上板４６，４７との間、左帯板５１の両端部と上板４４，４６との間、右帯板５２の両端部と上板４５，４７との間はそれぞれ突合せ溶接され、溶接部５４，５４，…が形成されている。
【００５２】
本実施の形態によるトラックフレーム４１は上述の如き構成を有するもので、センタフレーム４２の上板４３を構成する４枚の上板（左前上板４４，右前上板４５，左後上板４６，右後上板４７）間に、４枚の帯板（前帯板４９，後帯板５０，左帯板５１，右帯板５２）を設けることにより、丸胴４８（フランジ部４８Ｂ）の外周側を、４枚の上板４４，４５，４６，４７の円弧部４４Ａ，４５Ａ，４６Ａ，４７Ａと４枚の帯板４９，５０，５１，５２の円弧部４９Ａ，５０Ａ，５１Ａ，５２Ａとに全周に亘って溶接することができる。
【００５３】
このため、本実施の形態においても、上述した第１の実施の形態と同様に、上板４３と丸胴４８の外周側との間の溶接作業を１回の全周溶接によって完了することができ、溶接作業の作業性を向上することができる。また、各上板４４，４５，４６，４７および各帯板４９，５０，５１，５２と丸胴４８の外周側との間に、前端部と後端部のない環状の溶接部５３を形成することができるので、この溶接部５３に対する表面仕上げ作業を不要にでき、溶接作業に要する時間を大幅に短縮することができる。
【００５４】
しかも、本実施の形態では、上板４３をほぼ同一形状を有する左前上板４４，右前上板４５，左後上板４６，右後上板４７によって形成したので、各上板４４，４５，４６，４７の１枚あたりの面積を小さくできる。このため、例えば素材となる鋼板材から各上板４４，４５，４６，４７を無駄なく切断することができ、材料費の低減にも寄与することができる。
【００５５】
なお、上述した第１の実施の形態では、センタフレーム３２の上板３３を、丸胴３６の中心Ｏ１を通る前，後方向の仮想線Ａ１−Ａ１を境としてほぼ同一形状を有する左上板３４と右上板３５とにより構成し、これら左上板３４，右上板３５間に、丸胴３６のフランジ部３６Ｂ外周を跨ぐ前帯板３７，後帯板３８を設けることにより、丸胴３６の外周を２枚の上板３４，３５と２枚の帯板３７，３８とに全周溶接した場合を例に挙げている。
【００５６】
しかし、本発明はこれに限るものではなく、例えば図７に示す変形例のように、センタフレーム６１の上板６２を、丸胴３６の中心Ｏ１を通る左，右方向の仮想線Ｂ１−Ｂ１を境としてほぼ同一形状を有する前上板６３と後上板６４とにより構成し、これら前上板６３，後上板６４間に、丸胴３６の外周を跨ぐ左帯板６５，右帯板６６を設けることにより、丸胴３６の外周を各上板６３，６４と各帯板６５，６６とに全周溶接する構成としてもよい。
【００５８】
また、上述した各実施の形態では、旋回式建設機械のトラックフレームとして油圧ショベルのトラックフレームを例に挙げて説明したが、本発明はこれに限らず、例えば油圧クレーン等の他の旋回式建設機械のトラックフレームに適用してもよい。
【００５９】
【発明の効果】
以上詳述したように、請求項１の発明によれば、センタフレームの上板を左上板と右上板により構成し、該左上板と右上板との間には、丸胴のフランジ部外周を跨いで前帯板と後帯板を設ける構成としたので、丸胴のフランジ部外周側を前記左上板と右上板および前帯板と後帯板とに全周に亘って溶接することができる。このため、上板と丸胴のフランジ部外周側との間に１回の溶接作業によって全周溶接を施すことができ、このときの作業性を向上することができる。
【００６０】
また、左上板，右上板および前帯板，後帯板と丸胴のフランジ部との間には、前端部と後端部のない環状の溶接部が形成されるので、溶接部の前端部と後端部に対する煩わしい表面仕上げ作業を不要にでき、溶接作業に要する時間を短縮することができる。さらに、左上板と右上板および前帯板と後帯板との間にはほぼ均一な形状をもった溶接部を形成することができるので、両者間の溶接部の品質を高めることができる。
【００６１】
また、請求項２の発明によれば、センタフレームの上板を前上板，後上板により構成し、該前上板と後上板との間には、丸胴のフランジ部外周を跨いで左帯板と右帯板とを設ける構成としたので、丸胴のフランジ部外周側を前記前上板，後上板と左帯板，右帯板との全周に亘って溶接することができ、上板と丸胴のフランジ部外周側との間の溶接作業を１回の全周溶接によって効率よく行うことができる。
【００６２】
さらに、請求項３の発明によれば、センタフレームの上板を左前上板，右前上板，左後上板，右後上板からなる４枚の上板により構成し、左前上板と右前上板との間，左後上板と右後上板との間には丸胴のフランジ部外周を跨いで前帯板，後帯板を設けると共に、左前上板と左後上板との間，右前上板と右後上板との間には丸胴のフランジ部外周を跨いで左帯板，右帯板を設ける構成としたので、丸胴のフランジ部外周側を前記左前上板，右前上板，左後上板，右後上板からなる４枚の上板と、前帯板，後帯板，左帯板，右帯板からなる４枚の帯板とに全周に亘って溶接することができ、溶接作業の作業性を向上することができる。しかも、上板を４枚の左前上板，右前上板，左後上板，右後上板によって構成することにより、各上板の１枚あたりの面積を小さくできるので、例えば素材となる鋼板材等から左前上板，右前上板，左後上板，右後上板を無駄なく切断することができ、材料費の低減にも寄与することができる。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態によるトラックフレームを示す平面図である。
【図２】丸胴と帯板との溶接部を図１中の矢示II−II方向からみた拡大断面図である。
【図３】図１中の丸胴、各上板、各帯板等の要部を示す斜視図である。
【図４】第２の実施の形態によるトラックフレームを示す図１と同様位置の平面図である。
【図５】丸胴と帯板との溶接部を図４中の矢示Ｖ−Ｖ方向からみた拡大断面図である。
【図６】図４中の丸胴、各上板、各帯板等の要部を示す斜視図である。
【図７】本発明の変形例によるトラックフレームを示す平面図である。
【図８】従来技術によるトラックフレームを備えた油圧ショベルを示す正面図である。
【図９】従来技術によるトラックフレームを図８中の矢示IX−IX方向からみた一部破断の断面図である。
【図１０】従来技術によるトラックフレームを示す平面図である。
【図１１】従来技術によるトラックフレームにおいて丸胴と上板との間に溶接が施されていない部位を図１０中の矢示XI−XI方向からみた拡大断面図である。
【符号の説明】
１３下板
１４中板
１５円筒状中板
２６サイドフレーム
３２，４２センタフレーム
３４左上板
３５右上板
３６，４８丸胴
３７，４９前帯板
３８，５０後帯板
４４左前上板
４５右前上板
４６左後上板
４７右後上板
５１，６５左帯板
５２，６６右帯板[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a track frame of a swing type construction machine that constitutes a lower traveling body such as a hydraulic excavator or a hydraulic crane.
[0002]
[Prior art]
In general, a swivel construction machine such as a hydraulic excavator is provided with a lower traveling body, an upper revolving body that is pivotably mounted on the lower traveling body, and a front-side side of the upper revolving body that can be raised and lowered. It is roughly constituted by a working device.
[0003]
Therefore, a large hydraulic excavator will be described as an example of this type of conventional rotating construction machine and will be described with reference to FIGS.
[0004]
In the figure, 1 is a lower traveling body, 2 is an upper revolving body provided on the lower traveling body 1 via a swivel device 3 so as to be able to swivel, and the upper revolving body 2 includes a revolving frame 4 and a revolving frame 4 The cab 5, the building cover 6, the counterweight 7, etc. arranged in A working device (not shown) is provided on the front side of the upper swing body 2 so as to be able to move up and down.
[0005]
11 is a lower traveling body 1 As shown in FIGS. 9 to 11, the track frame 11 is roughly constituted by a center frame 12, a circular cylinder 20, and a side frame 26, which will be described later.
[0006]
Reference numeral 12 denotes a center frame that constitutes the central portion of the track frame 11. The center frame 12 is generally H-shaped as a whole, and has a total of four legs spaced forward and backward on both left and right ends. Portions 12A, 12A,... Are provided.
[0007]
Here, the center frame 12 includes a lower plate 13 formed in a substantially H shape with a steel plate or the like, and a plurality of middle plates 14, 14,... Made of a steel plate or the like standing on the upper surface side of the lower plate 13. A cylindrical intermediate plate 15 provided between the circular cylinder 20 and the lower plate 13 and supporting the circular cylinder 20 from below; an annular plate 16 provided on the inner peripheral side of the circular cylinder 20 and facing the lower plate 13; The upper plate 17 is fixed to the upper end side of each middle plate 14 so as to face the lower plate 13 and is formed with a strong frame structure.
[0008]
Reference numeral 17 denotes an upper plate that constitutes the center frame 12 together with the lower plate 13, the respective intermediate plates 14, the cylindrical intermediate plate 15, the annular plate 16, and the like. The upper left plate 18 and the upper right plate 19 have substantially the same shape with the virtual line A-A as a boundary. Here, the length dimension in the front and rear directions of the upper plates 18 and 19 is set to a dimension substantially equal to the outer diameter dimension of the circular cylinder 20 in order to reduce the material cost by making the steel plate material as small as possible. The upper plates 18 and 19 are respectively formed with arc portions 18A and 19A having an angle of less than 180 degrees with the center O of the circular cylinder 20 as the center.
[0009]
Reference numeral 20 denotes a round cylinder provided at the center on the upper surface side of the upper plate 17 constituting the center frame 12, and the circular cylinder 20 is formed in a large-diameter cylindrical shape. The outer periphery on the lower end side of the round cylinder 20 is welded to the arc portion 18A of the upper left plate 18 and the arc portion 19A of the upper right plate 19, and an arc-shaped weld portion 21 is provided between the upper left plate 18 and the round cylinder 20. An arcuate welded portion 22 is formed between the upper right plate 19 and the circular cylinder 20. Further, a large number of screw holes 20A, 20A,... Are formed at regular intervals in the circumferential direction on the upper end side of the round body 20, and a later-described turning wheel 23 is attached.
[0010]
Reference numeral 23 denotes a turning wheel attached to the upper end side of the round body 20, and the turning wheel 23 includes an inner ring 23A and an outer ring 23B which can rotate with respect to the inner ring 23A, and a turning motor (not shown) or the like. In addition, the swivel device 3 is configured. The inner ring 23 </ b> A of the turning wheel 23 is attached to the upper end surface of the round body 20 with a bolt 24, and the outer ring 23 </ b> B is attached to the turning frame 4 on the upper turning body 2 side with a bolt 25.
[0011]
Reference numerals 26 and 26 denote left and right side frames disposed on both the left and right sides of the center frame 12, respectively. Each side frame 26 is attached to the distal end side of each leg 12A of the center frame 12 via a bracket 27. , Extending forward and backward. A driving wheel 28 is provided on the rear end side of the side frame 26, an idler wheel 29 is provided on the front end side of the side frame 26, and a crawler belt 30 is wound between the driving wheel 28 and the idler wheel 29. Has been.
[0012]
The hydraulic excavator according to the prior art has the above-described configuration. The track frame 11 of the lower traveling body 1 is used for excavation work such as the weight of the upper revolving body 2 and the earth and sand via the round body 20 and the revolving wheel 23. Receives excavation reaction force from the work equipment.
[0013]
[Problems to be solved by the invention]
By the way, in the track frame 11 according to the above-described prior art, the upper plate 17 is constituted by the upper left plate 18 and the upper right plate 19, and an arc shape is formed between the upper plates 18 and 19 and the outer peripheral side of the circular cylinder 20. It is the structure which adheres by performing welding in the range of the welding parts 21 and 22. FIG.
[0014]
For this reason, welding over the entire circumference (full circumference welding) cannot be performed between the upper left plate 18 and the upper right plate 19 and the outer peripheral side of the round cylinder 20, and as shown in FIGS. Of the outer peripheral side of 20, the portion located between the upper plates 18 and 19 is not welded. Therefore, the track frame 11 according to the prior art requires at least two welding operations between the upper left plate 18 and the round drum 20 and between the upper right plate 19 and the round drum 20. There is a problem that will decrease.
[0015]
In addition, by welding between the upper left plate 18 and the circular cylinder 20 to form an arc-shaped weld 21 between the two, the front end 21A and the rear end 21B of the weld 21 are grounded. It is necessary to perform surface finishing to be ground using, for example. And since this surface finishing operation needs to be performed also on the surface of the front end part 22A and the rear end part 22B of the welded part 22 formed between the upper right plate 19 and the round cylinder 20, the surface finishing is performed four times in total. There is a problem that a large amount of time is spent on the surface finishing work.
[0016]
Furthermore, the shape of the welded portion 21 formed between the upper left plate 18 and the round cylinder 20 and the shape of the welded portion 22 formed between the upper right plate 19 and the round cylinder 20 are not uniform, There exists a problem that the quality of the welding part between the upper plates 18 and 19 and the round cylinder 20 will vary.
[0017]
The present invention has been made in view of the above-described problems of the prior art, and is a track frame for a swivel construction machine that can improve workability when welding between the upper plate of the center frame and a round cylinder. The purpose is to provide.
[0018]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention is generally provided in a center frame that is substantially H-shaped and has front and rear legs at both left and right ends, and a center portion on the upper surface side of the center frame. A round cylinder and left and right side frames mounted on the legs located on both the left and right sides of the center frame. The round cylinder is formed of a flanged cylindrical body having a flange portion integrally formed on the outer periphery on the lower end side. It is applied to the track frame of a swivel construction machine.
[0019]
A feature of the configuration adopted by the invention of claim 1 is that the center frame is provided on the lower plate via a plurality of middle plates on the lower plate and the round cylinder. Flange part Is composed of an upper left plate and an upper right plate to be welded, and between the upper left plate and the upper right plate , At the front side of the round cylinder Of the round body Flange part Between the upper left plate and the upper right plate across the outer periphery The front part of Front strip to be joined And a rear belt plate that connects the rear upper portion between the upper left plate and the upper right plate across the flange portion outer periphery of the circular drum at a position on the rear side of the round drum, and Of the round body Flange part Is , Its outer peripheral side The upper left plate , Upper right board , Front strip and Back strip For four plates consisting of The configuration is such that the entire circumference is welded.
[0020]
With this configuration, the center plate upper plate and round cylinder Flange part When welding between The flange part Can be welded to the upper left plate, the upper right plate, the front strip, and the rear strip over the entire circumference. For this reason, the upper plate and round cylinder Flange part Can be welded all around by a single welding operation, and the workability at this time can be improved. Also, upper left plate, upper right plate and front strip, rear strip and round cylinder Flange part Since an annular (endless) welded portion without a front end portion and a rear end portion is formed between the front end portion and the rear end portion, troublesome surface finishing operations on the front end portion and the rear end portion of the welded portion can be eliminated.
[0021]
According to the feature of the configuration adopted by the invention of claim 2, the center frame is provided on the lower plate and a plurality of middle plates on the lower plate, and the round cylinder Flange part Is composed of a front upper plate and a rear upper plate to be welded, and between the front upper plate and the rear upper plate. , At the position on the left side of the round cylinder Of the round body Flange part Between the front upper plate and the rear upper plate across the outer periphery Left side of Left strip And a right belt plate that joins the right upper portion between the front upper plate and the rear upper plate across the flange portion outer periphery of the circular drum at a position on the right side of the round drum, Of the round body Flange part Is Its outer periphery Front upper plate , Rear upper plate , Left strip and Right strip For four plates consisting of The configuration is such that the entire circumference is welded.
[0022]
With this configuration, the front upper plate, the rear upper plate of the center frame, and the left belt plate, the right belt plate and the round cylinder that connect between the upper plates are provided. Flange part The entire circumference can be welded between the outer circumference by a single welding operation, and the workability at this time can be improved.
[0023]
According to a feature of the configuration adopted by the invention of claim 3, the center frame is provided on the lower plate and a plurality of middle plates on the lower plate, and the round cylinder Flange part Is composed of four upper plates consisting of a left front upper plate, a right front upper plate, a left rear upper plate, and a right rear upper plate, and between the left front upper plate and the right front upper plate, At a position that is the front side of the round cylinder Of the round body Flange part Straddling the outer periphery between the left front upper plate and the right front upper plate The front part Establish a front strip to join ,Previous Between the left rear upper plate and the right rear upper plate, At the position behind the round cylinder Of the round body Flange part The left rear upper plate and the right rear upper plate straddle the outer periphery. The rear part Establish a rear strip ,Previous Between the left front upper plate and the left rear upper plate, At the position on the left side of the round cylinder Of the round body Flange part A left belt plate is provided to connect the left front upper plate and the left rear upper plate across the outer periphery. ,Previous Between the right front upper plate and the right rear upper plate, At the position on the right side of the round cylinder Of the round body Flange part A right belt plate that connects between the right front upper plate and the right rear upper plate across the outer periphery is provided, Flange part Is Its outer periphery Four upper plates comprising the left front upper plate, right front upper plate, left rear upper plate, right rear upper plate, and four strips comprising the front band plate, rear belt plate, left belt plate, and right belt plate. When Against the 8 plates The configuration is such that the entire circumference is welded.
[0024]
With this configuration, the center plate upper plate and round cylinder Flange part When welding between Of the flange portion Four upper plates consisting of left front upper plate, right front upper plate, left rear upper plate, right rear upper plate and front belt plate, rear belt plate, left belt plate, right belt plate on the outer peripheral side It can be welded to the plate over the entire circumference. For this reason, the upper plate and round cylinder Flange part Can be welded all around by a single welding operation, and the workability at this time can be improved.
[0025]
Moreover, the upper plate Left front upper plate, right front upper plate, left rear upper plate, right rear upper plate By configuring with 4 sheets, one upper plate (Left front upper plate, right front upper plate, left rear upper plate, right rear upper plate) Therefore, for example, each upper plate can be cut without waste from a plate material used as a material, which can contribute to a reduction in material cost.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of a track frame of a swing construction machine according to the present invention will be described with reference to FIGS. 1 to 7, taking a track frame of a large hydraulic excavator as an example. 1 to 3 show a first embodiment according to the present invention. In the present embodiment, the same components as those of the above-described conventional technology are denoted by the same reference numerals, and the description thereof is omitted.
[0027]
In FIG. 1, reference numeral 31 denotes a track frame applied to the present embodiment instead of the track frame 11 according to the prior art. The track frame 31 is substantially the same as the track frame 11 according to the prior art, The cylindrical body 36 and the side frame 26 are generally configured.
[0028]
Reference numeral 32 denotes a center frame constituting the central portion of the track frame 31. The center frame 32 has a substantially H-shape as a whole, and has a total of four legs spaced from the front and rear at the left and right ends. .. Are provided, and a side frame 26 is attached to the distal end side of each leg portion 32A via a bracket 27.
[0029]
The center frame 32 includes a lower plate 13, a plurality of middle plates 14, 14,... Standing on the upper surface side of the lower plate 13, and a cylinder provided between the round cylinder 36 and the lower plate 13. From the middle plate 15, the annular plate 16 provided on the inner peripheral side of the round cylinder 36, the upper plate 33 described later fixed to the upper end side of each middle plate 14 so as to face the lower plate 13, etc. It is formed with a strong frame structure.
[0030]
Reference numeral 33 denotes an upper plate constituting the center frame 32, and the upper plate 33 has substantially the same shape before and after the virtual line A1-A1 in the rear direction before passing through the center O1 of the circular cylinder 36, as in the prior art. The upper left board 34 and the upper right board 35 which have are comprised. Here, the length dimension in the front and rear directions of the upper plates 34 and 35 is set to a dimension substantially equal to the outer diameter dimension of the round cylinder 36 in order to reduce the material cost by making the steel plate material as a material as small as possible. Has been. The upper left plate 34 is formed with an arc portion 34A having an angle of less than 180 degrees centered on the center O1 of the round cylinder 36, and the upper right plate 35 is also less than 180 degrees centered on the center O1 of the round cylinder 36. An arc portion 35A having an angle of is formed.
[0031]
Reference numeral 36 denotes a circular cylinder applied to the present embodiment instead of the conventional circular cylinder 20. The circular cylinder 36 has a cylindrical portion 36A and a diameter extending to the lower end side of the cylindrical portion 36A over the entire circumference. Are formed as a cylindrical body with a flange, and a concave curved portion 36C formed over the entire circumference at a corner between the cylindrical portion 36A and the flange portion 36B. . Further, a large number of screw holes 36D, 36D,... For attaching the inner ring 23A of the turning wheel 23 are formed on the upper end side of the cylindrical portion 36A.
[0032]
37 and 38 are a front band plate and a rear band plate respectively provided between the upper plates 34 and 35 across the outer periphery of the flange portion 36B of the round body 36 in order to connect the upper left plate 34 and the upper right plate 35. The front band plate 37 and the rear band plate 38 are made of, for example, band steel having a thickness substantially equal to that of the upper plates 34 and 35.
[0033]
Here, the front belt plate 37 and the rear belt plate 38 are formed with arc portions 37A and 38A having substantially the same curvature as the outer periphery of the flange portion 36B of the round body 36, respectively, and on the tip side of these arc portions 37A and 38A. Is provided with a groove for forming a K-shaped groove between the flange portion 36B of the round body 36.
[0034]
The outer periphery of the flange portion 36B of the round body 36 is continuous over the entire circumference with the arc portions 34A and 35A of the upper left plate 34 and the upper right plate 35, and the arc portions 37A and 38A of the front strip plate 37 and the rear strip plate 38. Welding (all-around welding) is performed, and an annular (endless) welded portion 39 having no front end portion and rear end portion is formed on the outer peripheral side of the flange portion 36B of the circular cylinder 36.
[0035]
In addition, a butt welding is performed between both longitudinal ends of the front strip 37 and the upper plates 34 and 35, and between both longitudinal ends of the rear strip 38 and the upper plates 34 and 35, respectively. 40, 40,... Are formed.
[0036]
The track frame 31 according to the present embodiment has the above-described configuration, and the basic operation thereof is not particularly different from that according to the prior art.
[0037]
However, in the present embodiment, by providing the two strips 37 and 38 between the upper left plate 34 and the upper right plate 35 constituting the upper plate 33 of the center frame 32, the round cylinder 36 (flange portion 36B). The welding can be performed over the entire circumference between the outer peripheral side of the two and the arc portions 34A, 35A of the two upper plates 34, 35 and the arc portions 37A, 38A of the two strips 37, 38. It has become.
[0038]
Thereby, in this Embodiment, the welding operation between the upper board 33 and the outer peripheral side of the round cylinder 36 can be completed by one round of all-around welding. For this reason, for example, as described in the prior art, when the upper left plate 18 and the upper right plate 19 constituting the upper plate 17 are respectively welded to the outer peripheral side of the circular cylinder 20, at least two welding operations are required. Compared to the above, the workability of the welding work can be improved.
[0039]
Further, in the present embodiment, an annular welded portion 39 having no front end portion and no rear end portion is provided between the upper left plate 34, the upper right plate 35, the front belt plate 37, the rear belt plate 38 and the outer peripheral side of the round body 36. Can be formed. For this reason, for example, as described in the prior art, each end 21A, 21B of the welded portion 21 formed between the upper left plate 18 and the round cylinder 20, and between the upper right plate 19 and the round cylinder 20 is formed. The surface finishing operation for the end portions 22A and 22B of the welded portion 22 can be made unnecessary, and the time required for the welding operation can be greatly shortened.
[0040]
Furthermore, in the present embodiment, the upper plate 33 is formed by welding the upper left plate 34, the upper right plate 35, the front belt plate 37, the rear belt plate 38 and the outer peripheral side of the round body 36 over the entire circumference. An annular welded portion 39 having a substantially uniform shape can be formed between the outer periphery of the circular cylinder 36 and the quality of the welded portion 39 can be improved.
[0041]
Next, FIGS. 4 to 6 show a second embodiment according to the present invention. The feature of this embodiment is that the upper plate of the center frame is composed of four upper plates, and the space between these upper plates is shown. There is a configuration in which four belt plates are used for connection. In the present embodiment, the same components as those of the above-described conventional technology are denoted by the same reference numerals, and the description thereof is omitted.
[0042]
In the figure, reference numeral 41 denotes a track frame applied to this embodiment in place of the track frame 11 according to the prior art. The track frame 41 is substantially the same as the track frame 11 according to the prior art, and a center frame 42 described later and a round frame. The body 48 and the side frame 26 are roughly configured.
[0043]
Reference numeral 42 denotes a center frame that constitutes the central portion of the track frame 41. The center frame 42 has a substantially H-shape as a whole, and is separated from the front and rear sides at the left and right ends by a total of four legs. .. Are provided, and the side frame 26 is attached to the distal end side of each leg portion 42 </ b> A via a bracket 27.
[0044]
The center frame 42 includes a lower plate 13, a plurality of middle plates 14, 14,... Erected on the upper surface side of the lower plate 13, and a cylinder provided between the round cylinder 36 and the lower plate 13. Each of the inner plate 15, the annular plate 16 provided on the inner peripheral side of the round body 36, and the lower plate 13. Middle plate 14 and an upper plate 43, which will be described later, fixed to the upper end side of the frame 14, and has a strong frame structure.
[0045]
Reference numeral 43 denotes an upper plate constituting the center frame 42. The upper plate 43 has a virtual line A2-A2 in the front and rear directions and a virtual line B2-B2 in the left and right directions as a boundary before passing through the center O2 of the circular cylinder 48. The front left upper plate 44, the right front upper plate 45, the left rear upper plate 46, and the right rear upper plate 47 are formed in substantially the same shape.
[0046]
Here, the left front upper plate 44 is formed with an arc portion 44A having an angle of less than 90 degrees with the center O2 of the round cylinder 48 as the center. Similarly to the left front upper plate 44, the right front upper plate 45, the left rear upper plate 46, and the right rear upper plate 47 also have arc portions 45A having an angle of less than 90 degrees with the center O2 of the round cylinder 48 as the center. 46A and 47A are formed, respectively.
[0047]
48 is a round cylinder applied to the present embodiment in place of the conventional round cylinder 20. The circular cylinder 48 expands over the entire circumference to the cylindrical portion 48A and the lower end side of the cylindrical portion 48A. Are formed as a cylindrical body with a flange, and a concave curved portion 48C formed over the entire circumference at a corner between the cylindrical portion 48A and the flange portion 48B. . A large number of screw holes 48D, 48D,... For attaching the inner ring 23A of the swivel ring 23 are formed on the upper end side of the cylindrical portion 48A.
[0048]
49 is a front band plate provided between the left front upper plate 44 and the right front upper plate 45, and 50 is a rear band plate provided between the left rear upper plate 46 and the right rear upper plate 47. The plate 49 and the rear strip 50 are formed of, for example, a strip steel having a thickness substantially equal to that of the left front upper plate 44 and the like, and are paired in the front and rear directions across the outer periphery of the flange portion 48B of the round body 48. . Here, the front belt plate 49 and the rear belt plate 50 are formed with arc portions 49A and 50A having curvatures substantially equal to the outer periphery of the flange portion 48B of the round body 48, respectively, and are formed on the tip sides of the arc portions 49A and 50A. Is provided with a groove processing for forming a K-shaped groove between the flange 48B of the round body 48.
[0049]
51 is a left belt plate provided between the left front upper plate 44 and the left rear upper plate 46, and 52 is a right belt plate provided between the right front upper plate 45 and the right rear upper plate 47. The plate 51 and the right belt plate 52 are made of, for example, a steel strip having a thickness substantially equal to that of the left front upper plate 44 and the like, and are paired in the left and right directions across the outer periphery of the flange portion 48B of the round body 48. . Here, the left belt plate 51 and the right belt plate 52 are formed with arc portions 51A and 52A having substantially the same curvature as the outer periphery of the flange portion 48B of the circular body 48, respectively, and are formed on the distal ends of the arc portions 51A and 52A. Is provided with a groove processing for forming a K-shaped groove between the flange 48B of the round body 48.
[0050]
The outer periphery of the flange 48B of the round body 48, the left front upper plate 44, the right front upper plate 45, the left rear upper plate 46, the arc portions 44A, 45A, 46A, 47A of the right rear upper plate 47, the front belt plate 49, The arcs 49A, 50A, 51A, 52A of the rear belt plate 50, the left belt plate 51, and the right belt plate 52 are continuously welded over the entire circumference (full circumference welding). An annular (endless) welded portion 53 having no front end portion and rear end portion is formed on the outer peripheral side of the flange portion 48B of 48.
[0051]
Further, between the longitudinal ends of the front strip 49 and the upper plates 44 and 45, between the both ends of the rear strip 50 and the upper plates 46 and 47, both ends of the left strip 51 and the upper plate 44. , 46, and both ends of the right belt plate 52 and the upper plates 45, 47 are butt welded to form welds 54, 54,.
[0052]
The track frame 41 according to the present embodiment has the above-described configuration. The four upper plates (the left front upper plate 44, the right front upper plate 45, the left rear upper plate 46, and the like) constituting the upper plate 43 of the center frame 42. By providing four belt plates (front belt plate 49, rear belt plate 50, left belt plate 51, right belt plate 52) between the right rear upper plate 47), the outer periphery of the round cylinder 48 (flange 48B). The four sides of the upper plates 44, 45, 46, 47 are arc portions 44A, 45A, 46A, 47A and the four strip plates 49, 50, 51, 52 are arc portions 49A, 50A, 51A, 52A. It can be welded over the entire circumference.
[0053]
For this reason, also in the present embodiment, the welding operation between the upper plate 43 and the outer peripheral side of the circular cylinder 48 can be completed by one round of welding as in the first embodiment described above. It is possible to improve the workability of the welding work. Further, an annular welded portion 53 having no front end portion and no rear end portion is formed between each upper plate 44, 45, 46, 47 and each strip plate 49, 50, 51, 52 and the outer peripheral side of the circular cylinder 48. Therefore, the surface finishing operation for the welded portion 53 can be eliminated, and the time required for the welding operation can be greatly shortened.
[0054]
Moreover, in the present embodiment, the upper plate 43 is formed by the left front upper plate 44, the right front upper plate 45, the left rear upper plate 46, and the right rear upper plate 47 having substantially the same shape, so that each of the upper plates 44, 45, The area per sheet of 46 and 47 can be reduced. For this reason, for example, each upper plate 44, 45, 46, 47 can be cut | disconnected without waste from the steel plate material used as a raw material, and it can contribute also to reduction of material cost.
[0055]
In the first embodiment described above, the upper left plate 34 having substantially the same shape with the upper plate 33 of the center frame 32 having the virtual line A1-A1 in the rear direction before and after passing through the center O1 of the round cylinder 36 as a boundary. And an upper right plate 35. Between the upper left plate 34 and the upper right plate 35, a front belt plate 37 and a rear belt plate 38 that straddle the outer periphery of the flange portion 36B of the round drum 36 are provided. The case where the entire circumference is welded to two upper plates 34 and 35 and two strips 37 and 38 is given as an example.
[0056]
However, the present invention is not limited to this. For example, as in the modification shown in FIG. 7, the left and right virtual lines B1-B1 passing through the center O1 of the round cylinder 36 and the upper plate 62 of the center frame 61. A front upper plate 63 and a rear upper plate 64 having substantially the same shape as a boundary, and a left belt plate 65 and a right belt plate straddling the outer periphery of the round body 36 between the front upper plate 63 and the rear upper plate 64. By providing 66, it is good also as a structure which welds the outer periphery of the round cylinder 36 to each upper board 63,64 and each strip | belt board 65,66 on the perimeter.
[0058]
Further, in each of the above-described embodiments, the description has been given by taking the track frame of the hydraulic excavator as an example of the track frame of the swing construction machine. However, the present invention is not limited to this, and other swing construction such as a hydraulic crane is used. You may apply to the track frame of a machine.
[0059]
【The invention's effect】
As described in detail above, according to the first aspect of the present invention, the upper plate of the center frame is constituted by the upper left plate and the upper right plate, and a round cylinder is provided between the upper left plate and the upper right plate. Flange part Since the front strip and the rear strip are provided across the outer circumference, Flange part The outer peripheral side can be welded to the left upper plate, the upper right plate, the front band plate, and the rear band plate over the entire circumference. For this reason, the upper plate and round cylinder Flange part All-around welding can be performed between the outer peripheral side and the outer peripheral side, and workability at this time can be improved.
[0060]
Also, upper left plate, upper right plate and front strip, rear strip and round cylinder Flange part An annular weld with no front and rear ends is formed between the front and rear ends, which eliminates the need for cumbersome surface finishing operations on the front and rear ends of the weld and shortens the time required for welding. can do. Furthermore, since a welded portion having a substantially uniform shape can be formed between the upper left plate and the upper right plate and between the front band plate and the rear band plate, the quality of the welded portion between them can be improved.
[0061]
According to the invention of claim 2, the upper plate of the center frame is constituted by a front upper plate and a rear upper plate, and a round cylinder is provided between the front upper plate and the rear upper plate. Flange part Since the left belt plate and the right belt plate are provided across the outer circumference, Flange part The outer peripheral side can be welded over the entire circumference of the front upper plate, the rear upper plate, the left belt plate, and the right belt plate. Flange part The welding operation with the outer peripheral side can be efficiently performed by one round of welding.
[0062]
Further, according to the invention of claim 3, the upper plate of the center frame is constituted by four upper plates comprising a left front upper plate, a right front upper plate, a left rear upper plate, and a right rear upper plate, the left front upper plate and the right front plate. There is a round cylinder between the upper plate and between the left rear upper plate and the right rear upper plate. Flange part A front band plate and a rear band plate are provided across the outer periphery, and a round cylinder is provided between the left front upper plate and the left rear upper plate, and between the right front upper plate and the right rear upper plate. Flange part Since the left and right strips are provided across the outer circumference, Flange part On the outer periphery side, there are four upper plates composed of the left front upper plate, right front upper plate, left rear upper plate, and right rear upper plate, and four pieces of front belt plate, rear belt plate, left belt plate, and right belt plate. It can be welded to the strip over the entire circumference, and the workability of the welding work can be improved. In addition, since the upper plate is composed of four left front upper plates, right front upper plate, left rear upper plate, and right rear upper plate, the area of each upper plate can be reduced. The left front upper plate, the right front upper plate, the left rear upper plate, and the right rear upper plate can be cut without waste from the material and the like, which can contribute to the reduction of material costs.
[Brief description of the drawings]
FIG. 1 is a plan view showing a track frame according to a first embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of a welded portion between a circular cylinder and a belt plate as viewed from the direction of arrows II-II in FIG.
3 is a perspective view showing the main parts of the circular cylinder, each upper plate, each band plate, etc. in FIG. 1. FIG.
FIG. 4 is a plan view of the same position as FIG. 1 showing a track frame according to a second embodiment.
5 is an enlarged cross-sectional view of a welded portion between a circular cylinder and a belt plate as seen from the direction of arrows VV in FIG. 4;
6 is a perspective view showing the main parts of the circular cylinder, each upper plate, each band plate, etc. in FIG. 4;
FIG. 7 is a plan view showing a track frame according to a modification of the present invention.
FIG. 8 is a front view showing a hydraulic excavator provided with a track frame according to the prior art.
9 is a partially broken cross-sectional view of a track frame according to the prior art as seen from the direction of arrows IX-IX in FIG.
FIG. 10 is a plan view showing a track frame according to the prior art.
11 is an enlarged cross-sectional view of a portion of the track frame according to the prior art that is not welded between the round cylinder and the upper plate, as viewed from the direction of arrows XI-XI in FIG. 10;
[Explanation of symbols]
13 Lower plate
14 Middle plate
15 Cylindrical intermediate plate
26 Side frame
32, 42 Center frame
34 Upper left board
35 Upper right board
36, 48 round body
37, 49 Front strip
38,50 Rear strip
44 Left front upper plate
45 Front right upper plate
46 Left rear upper plate
47 Right rear upper plate
51,65 Left strip
52,66 Right strip

Claims

A center frame having a substantially H-shape as a whole and having front and rear legs at both left and right ends, a round cylinder provided at the center of the upper surface of the center frame, and left and right of the center frame left attached to the leg portion located on either side, Ri Do and a right side frame, the round barrel is swivel flange portion at the lower end outer circumference ing constituted by a cylindrical body with a flange which is integrally formed Truck truck frame
The center frame includes a lower plate, a left upper plate provided on the lower plate via a plurality of middle plates, and a flange portion of the round cylinder is welded, and an upper right plate.
Between the upper left plate and the upper right plate, a front band plate that connects the front upper portion between the upper left plate and the upper right plate across the flange outer periphery of the round drum at a position that is the front side of the round drum, A rear belt plate that connects the rear upper part between the upper left plate and the upper right plate across the outer periphery of the flange portion of the round cylinder at a position that becomes the rear side ,
The swivel characterized in that the flange portion of the round body has a configuration in which the outer peripheral side is welded to the four plates including the upper left plate , the upper right plate , the front band plate, and the rear band plate over the entire circumference. Truck frame of a construction machine.

A center frame having a substantially H-shape as a whole and having front and rear legs at both left and right ends, a round cylinder provided at the center of the upper surface of the center frame, and left and right of the center frame left attached to the leg portion located on either side, Ri Do and a right side frame, the round barrel is swivel flange portion at the lower end outer circumference ing constituted by a cylindrical body with a flange which is integrally formed Truck truck frame
The center frame includes a lower plate, and a front upper plate and a rear upper plate that are provided on the lower plate via a plurality of middle plates and to which the flange portion of the round cylinder is welded.
Between the front upper plate and the rear upper plate, a left belt plate that joins the left side part between the front upper plate and the rear upper plate across the flange part outer periphery of the round drum at a position that becomes the left side of the round drum , A right belt plate that joins the right upper part between the front upper plate and the rear upper plate straddling the outer periphery of the flange portion of the circular drum at a position that becomes the right side of the round drum ,
The flange portion of the round body has a configuration in which the outer peripheral side is welded over the entire circumference to four plates including the front upper plate , the rear upper plate , the left belt plate, and the right belt plate. Track frame of a swivel construction machine.

A center frame having a substantially H-shape as a whole and having front and rear legs at both left and right ends, a round cylinder provided at the center of the upper surface of the center frame, and left and right of the center frame left attached to the leg portion located on either side, Ri Do and a right side frame, the round barrel is swivel flange portion at the lower end outer circumference ing constituted by a cylindrical body with a flange which is integrally formed Truck truck frame
The center frame includes a lower plate, a left front upper plate, a right front upper plate, a left rear upper plate, and a right rear upper plate that are provided on the lower plate via a plurality of middle plates and to which the flange portion of the round cylinder is welded. It consists of four upper plates consisting of
Between the left front upper plate and the right front upper plate, a front band plate that connects the front part of the left front upper plate and the right front upper plate across the flange outer periphery of the round cylinder at a position that is the front side of the circular cylinder Provided ,
Between the front Kihidari after upper and right rear upper plate, after said left rear upper and right rear upper at the position where the rear side of the round cylinder across the flange portion outer periphery of the round cylinder Provide a back strip that connects the side parts ,
Between the front Stories left upper and left rear upper left splicing between said left upper and left rear upper straddle the flange outer periphery of the round cylinder at a position on the left side of the round cylinder Provided a strip ,
Between the front Symbol right front upper and right rear upper, right splicing between the right front upper and right rear upper right a position of the round cylinder across the flange portion outer periphery of the round cylinder Provided a strip,
The flange portion of the round body has an outer peripheral side of the four upper plates including the left front upper plate, the right front upper plate, the left rear upper plate, and the right rear upper plate, and the front belt plate, the rear belt plate, and the left belt. A track frame for a swivel construction machine, characterized in that welding is performed over the entire circumference of eight plates of four strips including a plate and a right strip.