JP3993758B2

JP3993758B2 - Method for assembling photosensitive drum drive device and method for assembling electrophotographic recording apparatus

Info

Publication number: JP3993758B2
Application number: JP2001331293A
Authority: JP
Inventors: 耕造田場; 朗川勾; 邦宏田中; 雅弘滝沢
Original assignee: パナソニックコミュニケーションズ株式会社
Priority date: 2001-10-29
Filing date: 2001-10-29
Publication date: 2007-10-17
Anticipated expiration: 2021-10-29
Also published as: JP2003131540A

Description

【０００１】
【発明の属する技術分野】
本発明は、感光体ドラムに動力を伝達するモータなどの駆動源と、駆動源から感光体ドラムに動力を伝達するギヤ、タイミングベルト、電磁クラッチなどの伝達手段と、感光体ドラムと同軸上に係合するドラム駆動軸と、互いに対向する２つの筐体と、からなる感光体ドラム駆動装置の組立方法及び電子写真記録装置の組立方法に関する。
【０００２】
【従来の技術】
従来、この種の感光体ドラム駆動装置及び電子写真記録装置では、画像を形成する上で最重要部品である感光体ドラムへ駆動源であるモータからの動力を伝達する手段として、噛合いの歯数に応じた周波数成分の速度変動による回転ムラ、いわゆるジッターを伴うギヤなどの伝達手段ではなく、感光体ドラムと同軸上に係合し、モータからの動力を直接、伝達するドラム駆動軸を用いるのが一般的である。
【０００３】
通常、モータ、ドラム駆動軸およびギヤなどの伝達手段を構成する各駆動関連部品は、位置決め及び特性保証の観点から、一つの駆動ユニットとして組立てた後、本体筐体に締結固定する。例えば、図１３に示すような構成である。
【０００４】
図１３においては、平面形状の第１板金１３０１に対してプレス加工等により折り曲げ加工が施された第２板金１３０２が固定されている。第１板金１３０１に固定された第２板金１３０２の内側には一定の空間が形成され、この空間に感光体ドラムの駆動源となるモータ１３０３が収納されている。モータ１３０３の軸先端に形成したギヤ１３０４が第２板金１３０２の所定位置に形成された穴部から突出している。このモータ１３０３の軸先端に形成したギヤ１３０４に、ドラム駆動軸１３０５に取り付けられたギヤ１３０６が噛合する。ドラム駆動軸１３０５は、第１板金１３０１及び第２板金１３０２の所定位置に形成された穴部１３０１Ａ及び１３０２Ａに挿入されている。ドラム駆動軸１３０５は、これらの穴部１３０１Ａ及び１３０２Ａにベアリング１３０７等の軸保持手段を介して保持されている。このように構成される駆動ユニットが本体筐体１３０８に固定される。本体筐体１３０８より内側に突出したドラム駆動軸１３０５の部分に感光体ドラム１３０９が取り付けられる。以下、このような感光体ドラム駆動装置の組立工程について説明する。
【０００５】
まず、図１４に示すように、所定位置に駆動源であるモータ１３０３を固定した、プレス加工等で作製した第２板金１３０２を、第１板金１３０１に位置決めする。両者の相対的な位置決めには両者の所定位置に形成された穴部１３０１Ａ及び１３０２Ａや両者を締結するビスが挿入される穴部１３０１Ｂ及び１３０２Ｂが利用される。その後、図１５に示すように、穴部１３０１Ｂ及び１３０２Ｂにビスを挿入することで第２板金１３０２側と第１板金１３０１とを締結固定する。
【０００６】
第１板金１３０１と第２板金１３０２とを固定した後、図１６に示すように、ギヤ１３０６が取り付けられたドラム駆動軸１３０５を、これらの第１板金１３０１及び第２板金１３０２の穴部１３０１Ａ及び１３０２Ａを貫通するように挿入する。その際、ドラム駆動軸１３０５は、回転自在に保持されるようにベアリング１３０７を介して取り付けられる。これにより、一つの駆動ユニットが構成される。
【０００７】
駆動ユニットを構成した後、図１７に示すように、ドラム駆動軸１３０５の端部が本体筐体１３０８に形成された穴部を通過して内側に突出するように駆動ユニットを本体筐体１３０８に取り付ける。そして、第１板金１３０１の所定位置において駆動ユニット側から本体筐体１３０８に対してビスにより締結固定する。最後に、図１８に示すように、本体筐体１３０８から内側に突出したドラム駆動軸１３０５を感光体ドラム１３０９の側面に挿入し、感光体ドラム１３０９を支持する。このようにしてこのような感光体ドラム駆動装置が組立てられる。
【０００８】
【発明が解決しようとする課題】
しかし、上述したような従来の組立方法においては、ドラム駆動軸１３０５の軸中心は、第１板金１３０１及び第２板金１３０２に形成された穴部１３０１Ａ及び１３０２Ａの相対位置により決定される。そして、これらの穴部１３０１Ａ及び１３０２Ａの相対位置は、第１板金１３０１に固定された第２板金１３０２の状態により決定される。
【０００９】
すなわち、第２板金１３０２に折り曲げ加工が適切に施され、第１板金１３０１に適切に固定された場合には、ドラム駆動軸１３０５の軸中心は予定された位置に配置される。このドラム駆動軸１３０５に感光体ドラム１３０９を係合させることでモータ１３０３の動力は適切に感光体ドラム１３０９に伝達される。しかし、第２板金１３０２に折り曲げ加工が適切に施されないまま第１板金１３０１に固定された場合には、ドラム駆動軸１３０５の軸中心が不適切となり、モータ１３０３の動力が適切に感光体ドラム１３０９に伝達されないという事態が生じ得る。
【００１０】
図１９は、第２板金１３０２に適切に折り曲げ加工が施されないまま第１板金１３０１に固定された状態を示す図であり、図２０は、図１９に示す状態においてドラム駆動軸１３０５が挿入された場合のドラム駆動軸１３０５周辺の拡大図を示す。
【００１１】
図１９では、第２板金１３０２の折り曲げ加工の工程において、図中に示す上面１９０１の長さよりも下面１９０２の長さが短く折り曲げられた場合について示している。このような第２板金１３０２を第１板金１３０１に固定したことによって、第２板金１３０２の所定位置に形成された穴部１３０２Ａが第１板金１３０１の所定位置に形成された穴部１３０１Ａよりも僅かに下方に配置されている。
【００１２】
このような位置関係を有する穴部１３０１Ａ及び１３０２Ａにドラム駆動軸１３０５を挿入すると、ドラム駆動軸１３０５は、図２０に示すように、その軸中心が本来予定されている位置よりも上方に傾いた状態で取り付けられることとなる。すなわち、本来、一点鎖線Ａにドラム駆動軸１３０５の軸中心が配置されるべき場合において、第２板金１３０２の折り曲げ精度の不具合に起因してドラム駆動軸１３０５の軸中心が一点鎖線Ｂの位置にずれている。このようなドラム駆動軸１３０５に感光体ドラム１３０９を取り付けた場合には、モータ１３０３の等速回転運動が感光体ドラム１３０９に不等速回転運動として伝達され、回転ムラ、いわゆるジッターが発生するという事態が生じることとなる。
【００１３】
このような不具合を防止するためには、第２板金１３０２を作製する際、高い精度で折り曲げ加工を施す必要がある。折り曲げ加工に高い精度が要求されるため、金型精度の向上や製作工数の増加など部品単価の増大となるという問題がある。
【００１４】
また、第１板金１３０１と第２板金１３０２間の距離及び両者の穴部１３０１Ａ及び１３０２Ａの位置を決める手段として、いずれか一方の板金に設けた基準軸の軸長を利用することが考えられる。しかし、この場合でも、高精度な軸を作製し、かつ、一方の板金にカシメなどにより固定する際にも垂直度を保証する必要がある。このため、構成要素の単価や検査工数などの増大要因となり、その結果、製品コストの増大につながるという事態が生じ得る。
【００１５】
本発明は、かかる実情に鑑みて為されたものであり、製品コストの増大を防止しつつ、ドラム駆動軸と感光体ドラムの位置関係に起因する不具合を確実に防止することができる感光体ドラム駆動装置の組立方法及び電子写真記録装置の組立方法を提供することを目的とする。
【００１６】
【課題を解決するための手段】
本発明は、感光体ドラムと同軸上に係合する駆動軸と、この駆動軸を通す第１穴部を有する平面形状の第１板金と、この第１板金と連結される平面部と前記第１板金に向けて開口した凹部とを有しこの凹部の内部に前記駆動軸を駆動する駆動系を収納し且つ前記平面部を前記第１板金と連結したときに前記第１板金と平行になる前記凹部の平面上に前記駆動軸を通す第２穴部を有する第２板金と、軸周面と同一形状かつ同一大きさの前記第１穴部から前記第２穴部に向け垂直に貫通して挿入された際に、一端部が第２穴部から突出しているとともに他端部が第１穴部位置より先に挿入されるのを制限するための部材を設け、前記第１穴部を有する第１板金の平面と前記第２穴部を有する第２板金の平面と間の平行度とともに前記第１穴部と前記第２穴部とを同軸上に形成する基準となる基準軸と、を具備する感光体ドラム駆動装置の組立方法であって、まず前記第１板金と前記第２板金とを合わせた状態で前記基準軸を該軸周面と同一形状かつ同一大きさの前記第１穴部及び前記第２穴部に垂直に貫通して挿入する第１工程と、次に前記基準軸を基準として前記第１穴部を有する第１板金の平面と前記第２穴部を有する第２板金の平面と間の平行度及び前記第１穴部と前記第２穴部とが同軸上であることを維持しながら両者を固定する第２工程と、次に前記第１穴部及び前記第２穴部から前記基準軸を外す第３工程と、次に前記第１穴部及び第２穴部に前記駆動軸を挿入する第４工程と、を具備するものである。
【００１７】
これによれば、基準軸を、ドラム駆動軸が挿入される該基準軸周面と同一形状かつ同一大きさの第１穴部から第２穴部に向け垂直に貫通させ、一端部が第２穴部から突出した状態で挿入しながら、第１穴部を平面に有する第１板金と第２穴部を平面に有する第２板金とを固定するので、これらの第１穴部と第２穴部との同軸度が確実に保持されると共に、前記第１穴部を有する第１板金の平面と前記第２穴部を有する第２板金の平面と間の平行度が確保される。次に、これらの第１穴部と第２穴部にドラム駆動軸が挿入され、そのドラム駆動軸に感光体ドラムが係合する。このため、感光体ドラムとドラム駆動軸との軸芯平行度が適切に保持されることとなり、ドラム駆動軸と感光体ドラムの位置関係に起因する不具合を確実に防止することができる。
【００１８】
【発明の実施の形態】
本発明の第１の態様に係る感光体ドラム駆動装置の組立方法は、感光体ドラムと同軸上に係合する駆動軸と、この駆動軸を通す第１穴部を有する平面形状の第１板金と、この第１板金と連結される平面部と前記第１板金に向けて開口した凹部とを有しこの凹部の内部に前記駆動軸を駆動する駆動系を収納し且つ前記平面部を前記第１板金と連結したときに前記第１板金と平行になる前記凹部の平面上に前記駆動軸を通す第２穴部を有する第２板金と、軸周面と同一形状かつ同一大きさの前記第１穴部から前記第２穴部に向け垂直に貫通して挿入された際に、一端部が第２穴部から突出しているとともに他端部が第１穴部位置より先に挿入されるのを制限するための部材を設け、前記第１穴部を有する第１板金の平面と前記第２穴部を有する第２板金の平面と間の平行度とともに前記第１穴部と前記第２穴部とを同軸上に形成する基準となる基準軸と、を具備する感光体ドラム駆動装置の組立方法であって、まず前記第１板金と前記第２板金とを合わせた状態で前記基準軸を該軸周面と同一形状かつ同一大きさの前記第１穴部及び前記第２穴部に垂直に貫通して挿入する第１工程と、次に前記基準軸を基準として前記第１穴部を有する第１板金の平面と前記第２穴部を有する第２板金の平面と間の平行度及び前記第１穴部と前記第２穴部とが同軸上であることを維持しながら両者を固定する第２工程と、次に前記第１穴部及び前記第２穴部から前記基準軸を外す第３工程と、次に前記第１穴部及び第２穴部に前記駆動軸を挿入する第４工程と、を具備するものである。
【００１９】
この方法によれば、基準軸を該軸周面と同一形状かつ同一大きさの第１穴部から第２穴部に向け垂直に貫通させて一端部が第２穴部から突出した状態で挿入しながら、この基準軸を基準として、第１穴部を有する第１板金の平面と第２穴部を有する第２板金の平面と間の平行度を維持しながら両者を固定する。さらに平行度を維持した状態で固定された第１板金及び第２板金のそれぞれの平面に形成された第１穴部及び第２穴部に、感光体ドラムと同軸上に係合する駆動軸が挿入される。これによれば、基準軸を、ドラム駆動軸が挿入される該基準軸周面と同一形状かつ同一大きさの第１穴部から第２穴部に向け垂直に貫通させ、一端部が第２穴部から突出した状態で挿入しながら、第１穴部を平面に有する第１板金と第２穴部を平面に有する第２板金とを固定するので、これらの第１穴部と第２穴部との同軸度が確実に保持されると共に、前記第１穴部を有する第１板金の平面と前記第２穴部を有する第２板金の平面と間の平行度が確保される。そして、これらの第１穴部と第２穴部にドラム駆動軸が挿入され、そのドラム駆動軸に感光体ドラムが係合する。このため、感光体ドラムとドラム駆動軸との軸芯平行度が適切に保持されることとなり、モータの等速回転運動が感光体ドラムに不等速回転運動として伝達され、回転ムラが発生するという事態を確実に回避することができる。
【００２０】
また、基準軸を該軸周面と同一形状かつ同一大きさの第１穴部から第２穴部に向け垂直に貫通して挿入され一端部が第２穴部から突出しているとともに他端部が第１穴部位置より先に挿入されるのを制限するための部材を設けることにより、基準軸が第１穴部から脱落することを防止する。さらに、第１板金と第２板金との平行度を確保する際、それぞれに形成された該軸周面と同一形状かつ同一大きさの第１穴部から第２穴部に向け垂直に貫通させて一端部が第２穴部から突出した状態で基準軸を挿入しながら固定している。このため、従来のように一方の板金に、高精度な長さを有し且つその板金に対して垂直度を保証する必要がある基準軸を作製する必要もない。したがって、製作工数の増加などによる部品単価の増大を回避することができるので、製品コストの増大を防止することができる。
【００２１】
本発明の第２の態様に係る感光体ドラム駆動装置の組立方法は、感光体ドラムと同軸上に係合する駆動軸と、この駆動軸を通す第１穴部を有する平面形状の第１板金と、この第１板金と連結される平面部と前記第１板金に向けて開口した凹部とを有しこの凹部の内部に前記駆動軸を駆動する駆動系を収納し且つ前記平面部を前記第１板金と連結したときに前記第１板金と平行になる前記凹部の平面上に前記駆動軸を通す第２穴部を有する第２板金と、軸周面と同一形状かつ同一大きさの前記第１穴部から前記第２穴部に向け貫通して挿入された際に、一端部が第２穴部から突出しているとともに他端部が第１穴部位置より先に挿入されるのを制限するための部材を設け、前記第１穴部を有する第１板金の平面と前記第２穴部を有する第２板金の平面と間の平行度とともに前記第１穴部と前記第２穴部とを同軸上に形成する基準となる基準軸と、を具備する感光体ドラム駆動装置の組立方法であって、まず前記第１板金と前記第２板金とを合わせた状態で前記基準軸を該軸周面と同一形状かつ同一大きさの前記第１穴部及び前記第２穴部に垂直に貫通して挿入する第１工程と、次に前記基準軸を基準として前記第１穴部を有する第１板金の平面と前記第２穴部を有する第２板金の平面と間の平行度及び前記第１穴部と前記第２穴部とが同軸上であることを維持しながら前記第１板金から前記第２板金に向けた方向で両者を第１ビスで固定する第２工程と、次に前記第１穴部及び前記第２穴部から前記基準軸を外す第３工程と、次に前記第１穴部及び前記第２穴部に前記駆動軸を挿入する第４工程と、次に前記第２板金から前記第１板金に向けた方向で前記第１板金を装置本体に第２ビスで固定する第５工程と、を具備するものである。
【００２２】
この方法によれば、基準軸を該軸周面と同一形状かつ同一大きさの第１穴部から第２穴部に向け垂直に貫通させて一端部が第２穴部から突出した状態で挿入しながら、この基準軸を基準として、第１穴部を有する第１板金の平面と第２穴部を有する第２板金の平面と間の平行度を維持しながら両者を固定する。さらに平行度を維持した状態で固定された第１板金及び第２板金のそれぞれの平面に形成された第１穴部及び第２穴部に、感光体ドラムと同軸上に係合する駆動軸が挿入される。これによれば、基準軸を、ドラム駆動軸が挿入される該基準軸周面と同一形状かつ同一大きさの第１穴部から第２穴部に向け垂直に貫通させ、一端部が第２穴部から突出した状態で挿入しながら、第１穴部を平面に有する第１板金と第２穴部を平面に有する第２板金とを固定するので、これらの第１穴部と第２穴部との同軸度が確実に保持されると共に、前記第１穴部を有する第１板金の平面と前記第２穴部を有する第２板金の平面と間の平行度が確保される。そして、これらの第１穴部と第２穴部にドラム駆動軸が挿入され、そのドラム駆動軸に感光体ドラムが係合する。このため、感光体ドラムとドラム駆動軸との軸芯平行度が適切に保持されることとなり、モータの等速回転運動が感光体ドラムに不等速回転運動として伝達され、回転ムラが発生するという事態を確実に回避することができる。
【００２３】
また、基準軸を該軸周面と同一形状かつ同一大きさの第１穴部から第２穴部に向け垂直に貫通して挿入され一端部が第２穴部から突出しているとともに他端部が第１穴部位置より先に挿入されるのを制限するための部材を設けることにより、基準軸が第１穴部から脱落することを防止する。さらに、第１板金と第２板金との平行度を確保する際、それぞれに形成された該軸周面と同一形状かつ同一大きさの第１穴部から第２穴部に向け垂直に貫通させて一端部が第２穴部から突出した状態で基準軸を挿入しながら固定している。このため、従来のように一方の板金に、高精度な長さを有し且つその板金に対して垂直度を保証する必要がある基準軸を作製する必要もない。したがって、製作工数の増加などによる部品単価の増大を回避することができるので、製品コストの増大を防止することができる。
【００２４】
さらに、第１板金と第２板金とを固定する際、第１板金から前記第２板金に向けた方向で両者を第１ビスで固定する一方、第２板金が固定された第１板金を装置本体に固定する際、第２板金から第１板金に向けた方向で第２ビスで固定している。このように第１ビス及び第２ビスの固定方向を相反する方向とすることにより、いずれのビスがどの部材を固定しているかを確実に判別することができる。したがって、本感光体ドラム駆動装置の組立作業が完了した後に、サービスマンがトラブル対応のため感光体ドラム駆動装置を装置本体から外す際に、誤って第１ビスを外し、その結果、ドラム駆動軸の軸芯平行度を狂わせるという事態を確実に回避することができる。
【００２５】
本発明の第３の態様は、第２の態様に係る感光ドラム駆動装置の組立方法において、前記第２板金との固定に用いる前記第１板金に形成されたビス穴は、前記第２板金端部を１回折曲げた平面部に形成したビス穴よりも大きいことを特徴とする。
【００２６】
この方法によれば、第１ビスを挿入するビス穴は、最初に挿入される第１板金に形成されたビス穴が、第１板金に形成されたビス穴を通過した後に挿入される第２板金に形成されたビス穴よりも大きくなっている。これによれば、第１板金に形成されたビス穴から第２板金に形成されたビス穴がわずかにずれた場合でも、第１板金に形成されたビス穴の許容範囲であれば、第１板金と第２板金とを確実に固定することができる。これにより、例えば、第１板金と第２板金に形成されたビス穴が同一の大きさであった場合に生じ得る、ビスを挿入することができない事態を回避することができるので、第１板金と第２板金との固定作業を簡略化することができる。
【００２７】
また、第１板金のビス穴を第２板金端部を１回折曲げた平面部に形成したビス穴よりも大きくすることにより、例えば、第２板金を１回の折曲げ加工で作製する場合には、第２板金の凹部の曲げ精度を緩和しても、第２板金の第２穴部と第１板金の第１穴部との位置関係を保ちつつ第２板金と第１板金とを固定でき、第２板金の凹部の曲がり誤差を第１板金のビス穴により吸収できるので、第２板金の加工精度を上げる必要がなくなり、その分コストを削減することができる。
【００２８】
本発明の第４の態様は、第２又は第３の態様に係る感光ドラム駆動装置の組立方法において、前記基準軸の挿入方向は、前記第１ビスの固定方向と同一であることを特徴とする。
【００２９】
この方法によれば、基準軸を挿入した後に第１ビスを固定する作業をする場合において、両者の作業を同一方向から行うことができる。これにより、作業者の体の位置を動かすか、あるいは、組立作業の対象物を動かす等の作業を行う必要がなくなる。したがって、本感光体ドラム駆動装置の組立作業の効率の向上を図ることができる。
【００３０】
本発明の第５の態様に係る電子写真記録装置の組立方法は、感光体ドラムと同軸上に係合する駆動軸と、この駆動軸を通す第１穴部を有する平面形状の第１板金と、この第１板金と連結される平面部と前記第１板金に向けて開口した凹部とを有しこの凹部の内部に前記駆動軸を駆動する駆動系を収納し且つ前記平面部を前記第１板金と連結したときに前記第１板金と平行になる前記凹部の平面上に前記駆動軸を通す第２穴部を有する第２板金と、軸周面と同一形状かつ同一大きさの前記第１穴部から前記第２穴部に向け貫通して挿入された際に、一端部が第２穴部から突出しているとともに他端部が第１穴部位置より先に挿入されるのを制限するための部材を設け、前記第１穴部を有する第１板金の平面と前記第２穴部を有する第２板金の平面と間の平行度とともに前記第１穴部と前記第２穴部とを同軸上に形成する基準となる基準軸と、を具備する電子写真記録装置の組立方法であって、まず前記第１板金と前記第２板金とを合わせた状態で前記基準軸を該軸周面と同一形状かつ同一大きさの前記第１穴部及び前記第２穴部に垂直に貫通して挿入する第１工程と、次に前記基準軸を基準として前記第１穴部を有する第１板金の平面と前記第２穴部を有する第２板金の平面と間の平行度及び前記第１穴部と前記第２穴部とが同軸上であることを維持しながら両者を固定する第２工程と、次に前記第１穴部及び前記第２穴部から前記基準軸を外す第３工程と、次に前記第１穴部及び第２穴部に前記駆動軸を挿入する第４工程と、を具備するものである。
【００３１】
この方法によれば、電子写真記録装置の組立方法において、前記第１の態様に記載のものと同じ効果及び作用を得ることができる。
【００４１】
以下、本発明の実施の形態について、図面を参照して詳細に説明する。
【００４２】
図１は、本発明の一実施の形態に係る感光体ドラム駆動装置が適用される電子写真記録装置１００の概略構成図である。図１に示すように、本電子写真記録装置１００は、上部に原稿の読み取りを行う読取ユニット１０１を備え、その下方に給紙、転写、記録、定着の処理を実行する本体ユニット１０２を備える。
【００４３】
本体ユニット１０２の底部に給紙カセット１０３が設置されている。給紙カセット１０３にセットされた用紙束から最上面の用紙がピックアップローラ１０４によって取り出される。
【００４４】
給紙カセット１０３から取り出された用紙は、給紙ローラ１０５によって本体ユニット１０２の底部から上方に向けて形成された紙パス１０６に送り込まれる。紙パス１０６には、本発明に係る用紙搬送装置における用紙の搬送手段としての複数の搬送ローラ１０７、１０８及び１０９が配置されている。搬送ローラ１０７、１０８及び１０９は、図示しない本体ユニット１０２の開閉カバーを開いて交換可能な構成になっている。
【００４５】
なお、本実施の形態では、上下３個の搬送ローラを配置した場合について示しているが、これに限定されることなく、搬送ローラの個数に関わらず適用可能である。例えば、搬送ローラが単一の場合にも適用可能である。
【００４６】
また、本実施の形態では、紙パス１０６上に配置された搬送ローラ１０７、１０８及び１０９について説明するが、これに限定されることない。用紙の搬送を行う搬送ローラであって、交換する必要があるものであれば、本電子写真記録装置１００のいかなる箇所の搬送ローラであっても適用可能である。
【００４７】
最も上方に配置された搬送ローラ１０９によって搬送された用紙は、搬送ローラ１１０によってレジストローラ１１１に渡される。レジストローラ１１１による用紙の搬送先には、図中矢印方向に回転する感光体ドラム１１２が配置されている。感光体ドラム１１２は、本実施の形態に係る感光体ドラム駆動装置にその側面で軸支されている。
【００４８】
感光体ドラム１１２の上方には、感光体ドラム１１２の表面に潜像画像を形成するＬＳＵ（Laser Scan Unit）１１３が配置されている。感光体ドラム１１２に形成された潜像画像に現像材（トナー）を付着させる現像装置１１４が感光体ドラム１１２に隣接して配置されている。現像装置１１４内部には現像材を攪拌・搬送する攪拌ローラと感光体ドラム１１２に現像材を付着させる現像ローラを備えている。
【００４９】
感光体ドラム１１２の下方には、感光体ドラム１１２に現像材が付着することで形成された画像を、搬送される用紙に転写する転写器１１５が設置されている。なお、感光体ドラム１１２上の画像と用紙の記録領域との位置調整はレジストローラ１１１によって制御される。
【００５０】
画像を転写し終わった感光体ドラム１１２の表面をクリーニングするクリーニングユニット１１６が感光体ドラム１１２に隣接して配置されている。画像が転写された用紙は搬送ベルト１１７によりさらに搬送される。搬送ベルト１１７の搬送先には定着ユニット１１８が配置されている。
【００５１】
定着ユニット１１８は、定着ローラ１１９と、定着ローラ１１９に対向配置された加圧ローラ１２０と、定着ローラ１１９に残留したトナーの剥離性を高めるためオイルを塗布するクリーニングローラ（不図示）とを備えている。定着ローラ１１９が用紙の記録面に熱を加え、加圧ローラ１２０が用紙を定着ローラ１１９との間で押圧することにより、用紙に画像が定着する。
【００５２】
定着ユニット１１８から排出された用紙は、排出ローラ１２１により本体ユニット１０２の外部に排出される。本体ユニット１０２から排出された用紙は、排紙トレイ１２２上に受け止められる。
【００５３】
定着ユニット１１８と排出ローラ１２１との間に、用紙を本体ユニット１０２の外部に排出するか、両面記録を行うための両面パス１２３に送り込むかを切り替える切替ガイド１２４が配置されている。両面パス１２３は、切替ガイド１２４の近傍から下方向に向かって形成され、その途中で略水平方向に向かって形成されている。
【００５４】
両面パス１２３に送り込まれた用紙は、反転ローラ１２５により両面パス１２３のうち、下方向に形成された部分１２３Ａの延長上に形成された反転パス１２６に一旦引き込まれる。反転パス１２６に用紙が引き込まれると、反転ローラ１２５が反転し、用紙を両面パス１２３のうち、略水平方向に形成された部分１２３Ｂに送り込む。この時点で用紙の表裏が反転する。
【００５５】
略水平方向に形成された両面パス１２３Ｂに送り込まれた用紙は、両面パス１２３Ｂ上に形成された搬送ローラ１２７、１２８及び１２９により搬送される。両面パス１２３Ｂは、搬送ローラ１１０の下方で紙パス１０６に連結されている。搬送ローラ１２７、１２８及び１２９により両面パス１２３Ｂを搬送し、紙パス１０６に送り込まれた用紙は、再度、感光体ドラム１１２の下方に送り込まれ、今度はその裏面に画像が形成される。
【００５６】
本体ユニット１０２の側面に給紙カセット１０３からの給紙以外の給紙を実現する手差しトレイ１３０が設けられている。手差しトレイ１３０に載置された用紙束の最上面の用紙がピックアップローラ１３１により取り込まれ、搬送ローラ１３２によりレジストローラ１１１に渡される。
【００５７】
図２に本実施の形態に係る感光体ドラム駆動装置の組立後の断面図を示し、図３に本実施の形態に係る感光体ドラム駆動装置の分解斜視部を示す。
【００５８】
本実施の形態に係る感光体ドラム駆動装置２００は、図２及び図３に示すように、感光体ドラム１１２の側面に対向配置された本体ユニット１０２の内部筐体２０１を挟んで感光体ドラム１１２の反対側に設置される。
【００５９】
本感光体ドラム駆動装置２００は、内部に後述するモータを収納する空間を確保した形状を有し、その中央近傍でドラム駆動軸２０２を支持している。ドラム駆動軸２０２は、本感光体ドラム駆動装置２００が設置された場合に、内部筐体２０１の所定位置に形成された穴部２０１Ａを通過して感光体ドラム１１２の側面に係合する。適切に係合されると、ドラム駆動軸２０２は、感光体ドラム１１２と同軸上に係合し、感光体ドラム１１２と一体となって回転する。
【００６０】
本感光体ドラム駆動装置２００は、内部筐体２０１に重ねられる平面形状の第１板金２０３に、折り曲げ加工などにより第１板金２０３に対して開口した形状を有する第２板金２０４を連結することで内部に一定の空間を設けている。なお、第２板金２０４は、第１板金２０３と平行な平面部２１１により第１板金２０３と連結される。この連結された第１板金２０３及び第２板金２０４（以下、「一対の板金」という）は、内部筐体２０１に対して、第１板金２０３から第２板金２０４に向けた方向で固定されるビス２０５とは反対側からビス２０６により固定される。なお、本実施の形態では、ビス２０５及びビス２０６にセルフタップ方式のビスを採用している。
【００６１】
本感光体ドラム駆動装置２００の内部の空間には、感光体ドラム１１２の駆動源としてのモータ２０７が収納されている。モータ２０７は、第２板金２０４の側面側であって、ドラム駆動軸２０２よりも上側の所定位置に固定されている。モータ２０７の駆動軸は、第２板金２０４の所定位置に形成された穴部２０４Ａを通過して第２板金２０４の外部に突出している。
【００６２】
ドラム駆動軸２０２の端部に取り付けられた駆動ギヤ２０８の周面がモータ２０７の駆動軸に噛合する。これにより、モータ２０７の動力が駆動ギヤ２０８を介してドラム駆動軸２０２に伝達される。
【００６３】
ドラム駆動軸２０２は、内部筐体２０１に形成された穴部２０１Ａに対応した位置であって、第１板金２０３に形成された穴部２０３Ａと、第２板金２０４に形成された穴部２０４Ｂを貫通している（図３参照）。ドラム駆動軸２０２は、穴部２０３Ａ及び穴部２０４Ｂにそれぞれ嵌め込まれたベアリング２０９及び２１０により回転可能に保持される。
【００６４】
次に、以上のような構成を有する本実施の形態に係る感光体ドラム駆動装置２００の組立工程について説明する。
【００６５】
まず、図４に示すように、所定位置にモータ２０７を固定した、プレス加工等で作製した第２板金２０４を、第１板金２０３の所定位置に合わせる。このとき、両者の位置合わせは、第１板金２０３及び第２板金２０４のそれぞれに形成された穴部２０３Ａ及び２０４Ｂの大体の位置を合わせるように行う。
【００６６】
次に、図５に示すように、第１板金２０３と第２板金２０４とを合わせた状態で、第１板金２０３及び第２板金２０４のそれぞれに形成された穴部２０３Ａ及び２０４Ｂを貫通するように、第１板金２０３側から基準軸５０１を挿入する。
【００６７】
ここで、基準軸５０１は、第１板金２０３と第２板金２０４との間の平行度の基準となる軸である。基準軸５０１は、第１板金２０３及び第２板金２０４のそれぞれに形成された穴部２０３Ａ及び２０４Ｂの形状に一致した形状を有する。本実施の形態では、穴部２０３Ａ及び２０４Ｂが同一の大きさの円形状を有し、基準軸５０１が同一の太さを有する円柱形状を有する。また、基準軸５０１は、その周面が穴部２０３Ａ及び２０４Ｂの円形状と一致するようになっている。
【００６８】
なお、基準軸５０１は、一対の板金に対する挿入作業の際、一定位置より先に挿入されるのを制限するための部材５０２が設けられている。この部材５０２は、基準軸５０１と一体形状としてもよいし、別途取り付ける構成であってもよい。
【００６９】
このような基準軸５０１を穴部２０３Ａ及び２０４Ｂに貫通させることにより、第１板金２０３と第２板金２０４とを一定の位置関係で合わせることができる。また、周面と同一形状の穴部２０３Ａ及び２０４Ｂに挿入されるので、これらに垂直に挿入されなければ基準軸５０１を挿入することはできない。このため、基準軸５０１が挿入した場合には、穴部２０３Ａ及び２０４Ｂが形成された第１板金２０３及び第２板金２０４の平行度が確保されることとなる。
【００７０】
このように一定の位置関係で合わせられた第１板金２０３と第２板金２０４とを、図６に示すように、第１板金２０３から第２板金２０４に向けた方向でビス２０５で締結する。基準軸５０１により一定の位置関係で合わせられた場合、第１板金２０３に形成されたビス２０５が挿入される穴部２０３Ｂと第２板金２０４に形成されたビス２０５が挿入される穴部２０４Ｃが対応した位置に配置される。
【００７１】
本実施の形態では、基準軸５０１を挿入した後にビス２０５を固定する作業をする場合において、両者の作業を同一方向から行うようにしている。これにより、作業者の体の位置を動かすか、あるいは、組立作業の対象物を動かす等の作業を行う必要がなくなる。したがって、本感光体ドラム駆動装置の組立作業の効率の向上を図ることができる。
【００７２】
図７にビス２０５の締結部分の拡大図を示す。図７に示すように、第１板金２０３に形成されたビス２０５が挿入される穴部２０３Ｂは、第２板金２０４に形成されたビス２０５が挿入される穴部２０４Ｃよりも大きな径を有している。なお、穴部２０３Ｂの径は、ビス２０５の傘部分より小さな径になっている。これによれば、第１板金２０３に形成された穴部２０３Ｂから第２板金２０４に形成された穴部２０４Ｃがわずかにずれた場合でも、第１板金２０３に形成された穴部２０３Ｂの許容範囲であれば、第１板金２０３と第２板金２０４とを確実に固定することができる。これにより、例えば、第１板金２０３と第２板金２０４に形成された穴部が同一の大きさであった場合に生じ得る、ビス２０５を挿入することができない事態を回避することができるので、第１板金２０３と第２板金２０４との固定作業を簡略化することができる。
【００７３】
仮にビス２０５を挿入する穴部２０３Ｂと穴部２０４Ｃが同一の大きさに設定された場合には、第１板金２０３と第２板金２０４の微小なズレでも、穴部２０３Ｂに挿入されたビス２０５が穴部２０４Ｃの位置に合致せず、ビス２０５をこれらの穴部に挿入できない事態が生じ得る。しかし、本実施の形態のようにしておけば、穴部２０３Ｂの内側に穴部２０４Ｃが収まっていれば、穴部２０４Ｃにビス２０５を挿入することができるので、上記のような事態の発生を回避することができる。
【００７４】
また、第１板金２０３の穴部２０３Ｂを第２板金２０４の穴部２０４Ｃよりも大きくすることにより、例えば、第２板金２０４を折り曲げ加工で作製する場合には、第２板金２０４の曲げ精度を緩和しても、ドラム駆動軸２０２が挿入される、第２板金２０４の穴部２０４Ｂと第１板金の穴部２０３Ａとの位置関係を保ちつつ、第２板金２０４と第１板金２０３とを固定でき、第２板金２０４の凹部の曲がり誤差を第１板金２０３の穴部２０３Ｂにより吸収できるので、第２板金２０４の加工精度を上げる必要がなくなり、その分コストを削減することができる。
【００７５】
ビス２０５で一対の板金を締結し終わった時点で第１板金２０３と第２板金２０４との位置関係を固定すると、図８に示すように、第１板金２０３及び第２板金２０４を貫通していた基準軸５０１を引き抜く。基準軸５０１を引き抜いた場合でも、第１板金２０３と第２板金２０４との位置関係は一定に固定されているので、第１板金２０３と第２板金２０４の平行度は維持される。
【００７６】
基準軸５０１を引き抜いた後、図９に示すように、駆動ギヤ２０８が一端に取り付けられたドラム駆動軸２０２を第２板金２０４に形成された穴部２０４Ｂから挿入する。その際、ドラム駆動軸２０２は、穴部２０３Ａ及び２０４Ｂにそれぞれ嵌め込まれるベアリング２１０及びベアリング２０９により回転可能に保持される。
【００７７】
ベアリング２１０は、ドラム駆動軸２０２の所定位置に取り付けられた状態であり、ドラム駆動軸２０２の挿入に応じて穴部２０４Ｂに嵌め込まれる。一方、ベアリング２０９は、ドラム駆動軸２０２の挿入方向の反対方向から穴部２０３Ａに嵌め込まれる。
【００７８】
ドラム駆動軸２０２が所定位置まで挿入すると、図１０に示すように、駆動ギヤ２０８の周面がモータ２０７の駆動軸に噛合する。このようにして本感光体ドラム駆動装置の駆動ユニットが構成される。今度はこの駆動ユニットを内部筐体２０１に取り付ける。
【００７９】
取り付けの際、内部筐体２０１に形成された穴部２０１Ａにドラム駆動軸２０２の一端を挿入する。そして、ドラム駆動軸２０２を保持しているベアリング２０９が穴部２０１Ａに収容されるように位置を合わせる。そして、第１板金２０３と内部筐体２０１を合わせた状態で、図１０に示すように、駆動ユニットを第１板金２０３側からビス２０６で締結する。
【００８０】
このように第１板金２０３と第２板金２０４とを固定する際、第１板金２０３から第２板金２０４に向けた方向で両者をビス２０５で固定する一方、第２板金２０４が固定された第１板金２０３を内部筐体２０１に固定する際、第２板金２０４から第１板金２０３に向けた方向でビス２０６で固定している。このようにビス２０５とビス２０６との固定方向を相反する方向とすることにより、いずれのビスがどの部材を固定しているかを確実に判別することができる。したがって、本感光体ドラム駆動装置の組立作業が完了した後に何らかの理由でいずれかのビスを取り外す必要が生じた場合などに誤って他のビスを取り外すような事態を確実に回避することができる。
【００８１】
図１１にビス２０６の締結部分周辺の拡大図を示す。図１１に示すように、第１板金２０３に形成されたビス２０６が挿入される穴部２０３Ｃは、内部筐体２０１に形成されたビス２０６が挿入される穴部２０１Ｂよりも大きな径を有している。なお、穴部２０３Ｃの径は、ビス２０６の傘部分より小さな径になっている。穴部２０３Ｃと穴部２０１Ｂとの大小関係は、ビス２０５を挿入する穴部２０３Ｂと穴部２０４Ｃの大小関係と同様である。
【００８２】
内部筐体２０１には、第１板金２０３から突出したビス２０５の傘部分を収容する穴部２０１Ｃが形成されている。第１板金２０３が内部筐体２０１に合わせられた場合でも、ビス２０５の傘部分は、穴部２０１Ｃに入り込む。このため、第１板金２０３から突出したビス２０５の傘部分が駆動ユニットの取付作業の障害となることはない。
【００８３】
ビス２０６により駆動ユニットを内部筐体２０１に固定すると、最後に、図１２に示すように、内部筐体２０１の内側に突出したドラム駆動軸２０２に対して、感光体ドラム１１２を係合する。このようにして本感光体ドラム駆動装置２００の組立工程が終了する。
【００８４】
このように本実施の形態の感光体ドラム駆動装置の組立方法によれば、基準部材を第１穴部と第２穴部に挿入した状態で、この基準部材を基準として第１板金と第２板金との平行度を維持しながら両者を固定する。さらに平行度を維持した状態で固定された第１板金及び第２板金のそれぞれに形成された第１穴部及び第２穴部に、感光体ドラムと同軸上に係合する駆動軸が挿入される。これによれば、ドラム駆動軸が挿入される第１穴部及び第２穴部に基準軸を挿入しながら第１板金と第２板金とを固定するので、これらの第１穴部と第２穴部との同軸度が確実に保持されると共に、第１板金と第２板金との平行度が確保される。これらの第１穴部と第２穴部にドラム駆動軸が挿入され、そのドラム駆動軸に感光体ドラムが係合する。このため、感光体ドラムとドラム駆動軸との軸芯平行度が適切に保持されることとなり、モータの等速回転運動が感光体ドラムに不等速回転運動として伝達され、回転ムラが発生するという事態を確実に回避することができる。
【００８５】
また、第１板金と第２板金との平行度を確保する際、それぞれに形成された第１穴部と第２穴部とに基準部材を挿入しながら固定している。このため、従来のように一方の板金に、高精度な長さを有し且つその板金に対して垂直度を保証する必要がある基準軸を作製する必要もない。したがって、製作工数の増加などによる部品単価の増大を回避することができるので、製品コストの増大を防止することができる。
【００８６】
【発明の効果】
以上説明したように、本発明によれば、製品コストの増大を防止しつつ、ドラム駆動軸と感光体ドラムの位置関係に起因する不具合を確実に防止することができる。
【図面の簡単な説明】
【図１】本発明の一実施の形態に係る感光体ドラム駆動装置が適用される電子写真記録装置の概略構成図
【図２】上記実施の形態に係る感光体ドラム駆動装置の組立後の断面図
【図３】上記実施の形態に係る感光体ドラム駆動装置の分解斜視部
【図４】上記実施の形態に係る感光体ドラム駆動装置の組立工程の断面図
【図５】上記実施の形態に係る感光体ドラム駆動装置の組立工程の断面図
【図６】上記実施の形態に係る感光体ドラム駆動装置の組立工程の断面図
【図７】上記実施の形態に係る感光体ドラム駆動装置のうち、第１板金を第２板金に締結するビスの締結部分の拡大図
【図８】上記実施の形態に係る感光体ドラム駆動装置の組立工程の断面図
【図９】上記実施の形態に係る感光体ドラム駆動装置の組立工程の断面図
【図１０】上記実施の形態に係る感光体ドラム駆動装置の組立工程の断面図
【図１１】上記実施の形態に係る感光体ドラム駆動装置のうち、第１板金を内部筐体に締結するビスの締結部分周辺の拡大図
【図１２】上記実施の形態に係る感光体ドラム駆動装置の組立工程の断面図
【図１３】従来の感光体ドラム駆動装置の構成を示す断面図
【図１４】従来の感光体ドラム駆動装置の組立工程の断面図
【図１５】従来の感光体ドラム駆動装置の組立工程の断面図
【図１６】従来の感光体ドラム駆動装置の組立工程の断面図
【図１７】従来の感光体ドラム駆動装置の組立工程の断面図
【図１８】従来の感光体ドラム駆動装置の組立工程の断面図
【図１９】従来の感光体ドラム駆動装置において、第２板金に適切に折り曲げ加工が施されないまま第１板金に固定された状態を示す図
【図２０】図１９に示す状態において、挿入されたドラム駆動軸周辺の拡大図
【符号の説明】
１００電子写真記録装置
１０１読取ユニット
１０２本体ユニット
１０７〜１０９搬送ローラ
２０１内部筐体
２０２ドラム駆動軸
２０３第１板金
２０４第２板金
２０５，２０６ビス
２０７モータ
２０８駆動ギヤ
２０９，２１０ベアリング
５０１基準軸[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a drive source such as a motor that transmits power to the photosensitive drum, transmission means such as a gear, timing belt, and electromagnetic clutch that transmit power from the drive source to the photosensitive drum, and coaxially with the photosensitive drum. The present invention relates to an assembling method of a photosensitive drum driving device and an assembling method of an electrophotographic recording apparatus, which include an engaging drum driving shaft and two housings facing each other.
[0002]
[Prior art]
Conventionally, in this type of photosensitive drum driving apparatus and electrophotographic recording apparatus, a meshing tooth is used as means for transmitting power from a motor as a driving source to a photosensitive drum which is the most important part in forming an image. It uses a drum drive shaft that engages coaxially with the photosensitive drum and directly transmits the power from the motor, rather than a transmission means such as a gear with a rotation unevenness due to the speed fluctuation of the frequency component corresponding to the number, so-called jitter. It is common.
[0003]
Usually, each drive-related component that constitutes a transmission means such as a motor, a drum drive shaft, and a gear is assembled and fixed as a single drive unit from the viewpoint of positioning and characteristic assurance. For example, the configuration is as shown in FIG.
[0004]
In FIG. 13, a second sheet metal 1302 that is bent by pressing or the like on the planar first sheet metal 1301 is fixed. A constant space is formed inside the second sheet metal 1302 fixed to the first sheet metal 1301, and a motor 1303 serving as a driving source for the photosensitive drum is accommodated in this space. A gear 1304 formed at the shaft tip of the motor 1303 protrudes from a hole formed at a predetermined position of the second sheet metal 1302. A gear 1306 attached to the drum drive shaft 1305 meshes with a gear 1304 formed at the shaft tip of the motor 1303. The drum drive shaft 1305 is inserted into holes 1301A and 1302A formed at predetermined positions on the first sheet metal 1301 and the second sheet metal 1302. The drum drive shaft 1305 is held in these holes 1301A and 1302A via shaft holding means such as a bearing 1307. The drive unit configured as described above is fixed to the main body housing 1308. A photosensitive drum 1309 is attached to a drum drive shaft 1305 projecting inward from the main body housing 1308. Hereinafter, an assembly process of such a photosensitive drum driving device will be described.
[0005]
First, as shown in FIG. 14, a second sheet metal 1302 manufactured by press working or the like in which a motor 1303 as a drive source is fixed at a predetermined position is positioned on the first sheet metal 1301. For the relative positioning of the two, holes 1301A and 1302A formed at predetermined positions of the two and holes 1301B and 1302B into which screws for fastening both are inserted are used. After that, as shown in FIG. 15, the second sheet metal 1302 side and the first sheet metal 1301 are fastened and fixed by inserting screws into the holes 1301B and 1302B.
[0006]
After fixing the first sheet metal 1301 and the second sheet metal 1302, as shown in FIG. 16, the drum drive shaft 1305 to which the gear 1306 is attached is attached to the holes 1301A and 1301A of the first sheet metal 1301 and the second sheet metal 1302. Insert so as to penetrate 1302A. At that time, the drum drive shaft 1305 is attached via a bearing 1307 so as to be held rotatably. Thereby, one drive unit is configured.
[0007]
After configuring the drive unit, as shown in FIG. 17, the drive unit is mounted on the main body casing 1308 so that the end of the drum drive shaft 1305 protrudes inward through a hole formed in the main body casing 1308. Install. Then, the first sheet metal 1301 is fastened and fixed with screws to the main body housing 1308 from the drive unit side at a predetermined position. Finally, as shown in FIG. 18, the drum drive shaft 1305 protruding inward from the main body housing 1308 is inserted into the side surface of the photosensitive drum 1309 to support the photosensitive drum 1309. In this way, such a photosensitive drum driving device is assembled.
[0008]
[Problems to be solved by the invention]
However, in the conventional assembly method as described above, the shaft center of the drum drive shaft 1305 is determined by the relative positions of the holes 1301A and 1302A formed in the first sheet metal 1301 and the second sheet metal 1302. The relative positions of these holes 1301 A and 1302 A are determined by the state of the second sheet metal 1302 fixed to the first sheet metal 1301.
[0009]
That is, when the second sheet metal 1302 is appropriately bent and fixed to the first sheet metal 1301, the axis center of the drum drive shaft 1305 is disposed at a predetermined position. By engaging the photosensitive drum 1309 with the drum driving shaft 1305, the power of the motor 1303 is appropriately transmitted to the photosensitive drum 1309. However, when the second sheet metal 1302 is fixed to the first sheet metal 1301 without being properly bent, the axis center of the drum drive shaft 1305 becomes inappropriate, and the power of the motor 1303 is appropriately adjusted to the photosensitive drum 1309. It can happen that it is not transmitted to.
[0010]
FIG. 19 is a view showing a state in which the second sheet metal 1302 is fixed to the first sheet metal 1301 without being appropriately bent, and FIG. 20 is a state in which the drum drive shaft 1305 is inserted in the state shown in FIG. An enlarged view of the periphery of the drum drive shaft 1305 is shown.
[0011]
FIG. 19 shows a case where the length of the lower surface 1902 is bent shorter than the length of the upper surface 1901 shown in the drawing in the step of bending the second sheet metal 1302. By fixing the second sheet metal 1302 to the first sheet metal 1301, the hole 1302A formed at a predetermined position of the second sheet metal 1302 is slightly smaller than the hole 1301A formed at a predetermined position of the first sheet metal 1301. It is arranged below.
[0012]
When the drum drive shaft 1305 is inserted into the holes 1301A and 1302A having such a positional relationship, the drum drive shaft 1305 is tilted upward from the originally planned position as shown in FIG. It will be attached in the state. In other words, when the axis center of the drum drive shaft 1305 should be placed on the alternate long and short dash line A, the axis center of the drum drive shaft 1305 is positioned at the position of the alternate long and short dash line B due to the bending accuracy of the second sheet metal 1302. It's off. When the photosensitive drum 1309 is attached to such a drum drive shaft 1305, the constant speed rotational motion of the motor 1303 is transmitted to the photosensitive drum 1309 as an unequal speed rotational motion, which causes rotational unevenness, so-called jitter. Things will happen.
[0013]
In order to prevent such a problem, it is necessary to perform bending with high accuracy when the second sheet metal 1302 is manufactured. Since high accuracy is required for the bending process, there is a problem that the unit unit price increases, such as improvement of mold accuracy and increase of manufacturing man-hours.
[0014]
Further, as a means for determining the distance between the first sheet metal 1301 and the second sheet metal 1302 and the positions of the hole portions 1301A and 1302A, it is conceivable to use the axial length of the reference axis provided in one of the sheet metals. However, even in this case, it is necessary to guarantee the perpendicularity when a highly accurate shaft is manufactured and fixed to one sheet metal by caulking or the like. For this reason, it becomes an increase factor, such as a unit price of a component, and inspection man-hours, As a result, the situation which leads to increase in product cost may arise.
[0015]
SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and a photosensitive drum capable of reliably preventing problems caused by the positional relationship between the drum drive shaft and the photosensitive drum while preventing an increase in product cost. It is an object to provide an assembling method of a driving device and an assembling method of an electrophotographic recording apparatus.
[0016]
[Means for Solving the Problems]
The present invention provides a drive shaft that is coaxially engaged with the photosensitive drum, a planar first sheet metal having a first hole portion through which the drive shaft passes, a planar section coupled to the first sheet metal, and the first plate. A recess having an opening toward one sheet metal is housed, and a drive system for driving the drive shaft is housed in the recess and is parallel to the first sheet metal when the planar portion is connected to the first sheet metal. A second sheet metal having a second hole for passing the drive shaft on the plane of the recess; Same shape and size as the shaft circumference From the first hole toward the second hole Vertically Inserted through When Provided with a member for limiting one end projecting from the second hole and inserting the other end ahead of the first hole position A plane of the first sheet metal having the first hole and a plane of the second sheet metal having the second hole. It becomes a standard which forms the 1st hole and the 2nd hole on the same axis with the parallelism between Reference axis And a method of assembling the photosensitive drum driving device, wherein the first sheet metal and the second sheet metal are combined together. The reference shaft has the same shape and the same size as the shaft circumferential surface. In the first hole and the second hole Vertically A first step of inserting through and then said Reference axis Based on Between the plane of the first sheet metal having the first hole and the plane of the second sheet metal having the second hole. A second step of fixing the first hole and the second hole while maintaining the parallelism of the first hole and the second hole, and then from the first hole and the second hole. Reference axis And a fourth step of inserting the drive shaft into the first hole portion and the second hole portion.
[0017]
According to this, The reference axis Drum drive shaft is inserted The same shape and the same size as the reference shaft peripheral surface From the first hole to the second hole Vertically While inserting, with one end protruding from the second hole, Has a first hole in the plane With the first sheet metal Has a second hole in the plane Since the second sheet metal is fixed, the coaxiality between the first hole and the second hole is reliably maintained, Between the plane of the first sheet metal having the first hole and the plane of the second sheet metal having the second hole. Parallelism is ensured. Next, a drum drive shaft is inserted into the first hole portion and the second hole portion, and the photosensitive drum is engaged with the drum drive shaft. For this reason, the axial parallelism between the photosensitive drum and the drum driving shaft is appropriately maintained, and it is possible to surely prevent problems caused by the positional relationship between the drum driving shaft and the photosensitive drum.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
The method for assembling the photosensitive drum driving device according to the first aspect of the present invention includes a driving shaft that is coaxially engaged with the photosensitive drum, and a planar first sheet metal having a first hole through which the driving shaft passes. And a planar portion connected to the first sheet metal and a recess opening toward the first sheet metal, and a drive system for driving the drive shaft is housed in the recess and the planar portion is A second sheet metal having a second hole through which the drive shaft passes on a plane of the recess that is parallel to the first sheet metal when connected to the first sheet metal; Same shape and size as the shaft circumference From the first hole toward the second hole Vertically Inserted through When Provided with a member for limiting one end projecting from the second hole and inserting the other end ahead of the first hole position A plane of the first sheet metal having the first hole and a plane of the second sheet metal having the second hole. It becomes a standard which forms the 1st hole and the 2nd hole on the same axis with the parallelism between Reference axis And a method of assembling the photosensitive drum driving device, wherein the first sheet metal and the second sheet metal are combined together. The reference shaft has the same shape and the same size as the shaft circumferential surface. In the first hole and the second hole Vertically A first step of inserting through and then said Reference axis Based on Between the plane of the first sheet metal having the first hole and the plane of the second sheet metal having the second hole. A second step of fixing the first hole and the second hole while maintaining the parallelism and the first hole and the second hole are coaxial, and then from the first hole and the second hole Reference axis And a fourth step of inserting the drive shaft into the first hole portion and the second hole portion.
[0019]
According to this method, Reference axis The Same shape and size as the shaft circumference From the first hole to the second hole Vertically While inserting, with one end protruding from the second hole, Reference axis Based on Between the plane of the first sheet metal having the first hole and the plane of the second sheet metal having the second hole. Both are fixed while maintaining parallelism. Furthermore, each of the 1st sheet metal and the 2nd sheet metal which were fixed in the state which maintained parallelism Plane A drive shaft that is coaxially engaged with the photosensitive drum is inserted into the first hole portion and the second hole portion that are formed in FIG. According to this, The reference axis Drum drive shaft is inserted The same shape and the same size as the reference shaft peripheral surface From the first hole to the second hole Vertically While inserting, with one end protruding from the second hole, Has a first hole in the plane With the first sheet metal Has a second hole in the plane Since the second sheet metal is fixed, the coaxiality between the first hole and the second hole is reliably maintained, Between the plane of the first sheet metal having the first hole and the plane of the second sheet metal having the second hole. The parallelism is ensured. A drum drive shaft is inserted into the first hole portion and the second hole portion, and the photosensitive drum is engaged with the drum drive shaft. For this reason, the axial parallelism between the photosensitive drum and the drum drive shaft is appropriately maintained, and the constant speed rotation motion of the motor is transmitted to the photosensitive drum as the non-uniform speed rotation motion, resulting in uneven rotation. This situation can be avoided reliably.
[0020]
Also, Reference axis The Same shape and size as the shaft circumference From the first hole to the second hole Vertically By providing a member that is inserted through and has one end projecting from the second hole portion and restricting the other end portion from being inserted before the first hole portion position, the reference shaft becomes the first hole. Prevents falling off the part. Furthermore, when securing the parallelism between the first sheet metal and the second sheet metal, each was formed Same shape and size as the shaft circumference From the first hole to the second hole Vertically With one end protruding from the second hole Reference axis It is fixed while inserting. For this reason, it is not necessary to produce a reference axis which has a highly accurate length and needs to guarantee the perpendicularity to the one sheet metal as in the prior art. Therefore, it is possible to avoid an increase in the unit cost due to an increase in manufacturing man-hours and the like, thereby preventing an increase in product cost.
[0021]
The method for assembling the photosensitive drum driving device according to the second aspect of the present invention includes a planar first sheet metal having a driving shaft that is coaxially engaged with the photosensitive drum and a first hole through which the driving shaft passes. And a planar portion connected to the first sheet metal and a recess opening toward the first sheet metal, and a drive system for driving the drive shaft is housed in the recess and the planar portion is A second sheet metal having a second hole through which the drive shaft passes on a plane of the recess that is parallel to the first sheet metal when connected to the first sheet metal; Same shape and size as the shaft circumference Inserted through the first hole part toward the second hole part When Provided with a member for limiting one end projecting from the second hole and inserting the other end ahead of the first hole position , Between the plane of the first sheet metal having the first hole and the plane of the second sheet metal having the second hole. It becomes a standard for forming the first hole and the second hole on the same axis together with the parallelism. Reference axis And a method of assembling the photosensitive drum driving device, wherein the first sheet metal and the second sheet metal are combined together. The reference shaft has the same shape and the same size as the shaft circumferential surface. In the first hole and the second hole Vertically A first step of inserting through and then said Reference axis Based on Between the plane of the first sheet metal having the first hole and the plane of the second sheet metal having the second hole. A second screw that fixes both the first and second holes in the direction from the first sheet metal to the second sheet metal while maintaining the parallelism and the first hole and the second hole on the same axis. Step, and then from the first hole and the second hole Reference axis A third step in which the drive shaft is inserted into the first hole portion and the second hole portion, and then the second sheet metal in the direction from the second sheet metal toward the first sheet metal. And a fifth step of fixing one sheet metal to the apparatus main body with a second screw.
[0022]
According to this method, Reference axis The Same shape and size as the shaft circumference From the first hole to the second hole Vertically While inserting, with one end protruding from the second hole, Reference axis Based on Between the plane of the first sheet metal having the first hole and the plane of the second sheet metal having the second hole. Both are fixed while maintaining parallelism. Furthermore, each of the 1st sheet metal and the 2nd sheet metal which were fixed in the state which maintained parallelism Plane A drive shaft that is coaxially engaged with the photosensitive drum is inserted into the first hole portion and the second hole portion that are formed in FIG. According to this, The reference axis Drum drive shaft is inserted The same shape and the same size as the reference shaft peripheral surface From the first hole to the second hole Vertically While inserting, with one end protruding from the second hole, Has a first hole in the plane With the first sheet metal Has a second hole in the plane Since the second sheet metal is fixed, the coaxiality between the first hole and the second hole is reliably maintained, Between the plane of the first sheet metal having the first hole and the plane of the second sheet metal having the second hole. Parallelism is ensured. A drum drive shaft is inserted into the first hole portion and the second hole portion, and the photosensitive drum is engaged with the drum drive shaft. For this reason, the axial parallelism between the photosensitive drum and the drum drive shaft is appropriately maintained, and the constant speed rotation motion of the motor is transmitted to the photosensitive drum as the non-uniform speed rotation motion, resulting in uneven rotation. This situation can be avoided reliably.
[0023]
Also, Reference axis The Same shape and size as the shaft circumference From the first hole to the second hole Vertically By providing a member that is inserted through and has one end projecting from the second hole portion and restricting the other end portion from being inserted before the first hole portion position, the reference shaft becomes the first hole. Prevents falling off the part. Furthermore, when securing the parallelism between the first sheet metal and the second sheet metal, each was formed Same shape and size as the shaft circumference From the first hole to the second hole Vertically With one end protruding from the second hole Reference axis It is fixed while inserting. For this reason, it is not necessary to produce a reference axis which has a highly accurate length and needs to guarantee the perpendicularity to the one sheet metal as in the prior art. Therefore, it is possible to avoid an increase in the unit cost due to an increase in manufacturing man-hours and the like, thereby preventing an increase in product cost.
[0024]
Further, when the first sheet metal and the second sheet metal are fixed, the first sheet metal with the second sheet metal fixed is fixed to the first sheet metal in the direction from the first sheet metal to the second sheet metal. When fixing to the main body, the second sheet metal is fixed in the direction from the second sheet metal to the first sheet metal. Thus, by setting the fixing directions of the first screw and the second screw to be opposite directions, it is possible to reliably determine which member is fixed by which screw. Therefore, after the assembly work of the photosensitive drum driving device is completed, when the serviceman removes the photosensitive drum driving device from the apparatus main body for troubleshooting, the first screw is mistakenly removed, and as a result, the drum driving shaft It is possible to surely avoid the situation that the parallelism of the axis of the lens is distorted.
[0025]
According to a third aspect of the present invention, in the method for assembling the photosensitive drum driving device according to the second aspect, the screw hole formed in the first sheet metal used for fixing to the second sheet metal is the second sheet metal. The end was formed on a flat part bent once It is larger than the screw hole.
[0026]
According to this method, the screw hole into which the first screw is inserted is the second screw hole that is inserted after the screw hole formed in the first sheet metal inserted first passes through the screw hole formed in the first sheet metal. It is larger than the screw hole formed in the sheet metal. According to this, even if the screw hole formed in the second sheet metal is slightly shifted from the screw hole formed in the first sheet metal, the first hole is within the allowable range of the screw hole formed in the first sheet metal. The sheet metal and the second sheet metal can be securely fixed. As a result, for example, it is possible to avoid a situation in which the screws cannot be inserted, which may occur when the screw holes formed in the first sheet metal and the second sheet metal have the same size. And the fixing work of the second sheet metal can be simplified.
[0027]
Also, screw holes in the first sheet metal The end was formed on a flat part bent once By making it larger than the screw hole, for example, the second sheet metal 1 time In the case of producing by bending, the second sheet metal is maintained while maintaining the positional relationship between the second hole part of the second sheet metal and the first hole part of the first sheet metal even if the bending accuracy of the concave part of the second sheet metal is eased. Since the sheet metal and the first sheet metal can be fixed, and the bending error of the concave portion of the second sheet metal can be absorbed by the screw hole of the first sheet metal, there is no need to increase the processing accuracy of the second sheet metal, and the cost can be reduced accordingly. it can.
[0028]
According to a fourth aspect of the present invention, in the method for assembling the photosensitive drum driving device according to the second or third aspect, Reference axis The insertion direction is the same as the fixing direction of the first screw.
[0029]
According to this method, Reference axis When the first screw is fixed after inserting the first screw, both of the operations can be performed from the same direction. As a result, it is not necessary to move the position of the worker's body or move an object to be assembled. Therefore, it is possible to improve the efficiency of assembling work of the photosensitive drum driving device.
[0030]
An assembly method of the electrophotographic recording apparatus according to the fifth aspect of the present invention includes: A drive shaft that is coaxially engaged with the photosensitive drum, a planar first sheet metal having a first hole through which the drive shaft passes, a planar section coupled to the first sheet metal, and the first sheet metal A recess that is open and has a recess in which the drive system for driving the drive shaft is housed and the plane of the recess that is parallel to the first sheet metal when the plane is coupled to the first sheet metal. When the second sheet metal having the second hole portion through which the drive shaft passes is inserted and inserted through the first hole portion having the same shape and the same size as the shaft peripheral surface toward the second hole portion. A plane of the first sheet metal having the first hole provided with a member for restricting the one end projecting from the second hole and restricting the other end to be inserted before the position of the first hole. The first hole and the second hole together with the parallelism between the second metal plate and the plane of the second sheet metal having the second hole. An assembly method of an electrophotographic recording apparatus comprising a reference axis as a reference formed above, wherein the reference axis is set to the shaft peripheral surface in a state where the first sheet metal and the second sheet metal are first combined. A first step of vertically inserting the first hole and the second hole of the same shape and the same size, and then the first sheet metal having the first hole with reference to the reference axis A second step of fixing both of the parallelism between the plane and the plane of the second sheet metal having the second hole portion and maintaining the first hole portion and the second hole portion on the same axis. Next, a third step of removing the reference shaft from the first hole and the second hole, and a fourth step of inserting the drive shaft into the first hole and the second hole, It has .
[0031]
According to this method, In the assembly method of the electrophotographic recording apparatus, Said 1 The same effects and actions as described in the embodiment can be obtained.
[0041]
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0042]
FIG. 1 is a schematic configuration diagram of an electrophotographic recording apparatus 100 to which a photosensitive drum driving apparatus according to an embodiment of the present invention is applied. As shown in FIG. 1, the electrophotographic recording apparatus 100 includes a reading unit 101 that reads a document at the top, and a main unit 102 that performs paper feeding, transfer, recording, and fixing processes below the reading unit 101.
[0043]
A paper feed cassette 103 is installed at the bottom of the main unit 102. The uppermost sheet is taken out by the pickup roller 104 from the sheet bundle set in the sheet feeding cassette 103.
[0044]
The paper taken out from the paper feed cassette 103 is fed by a paper feed roller 105 into a paper path 106 formed upward from the bottom of the main unit 102. In the paper path 106, a plurality of transport rollers 107, 108, and 109 are disposed as a paper transport means in the paper transport device according to the present invention. The transport rollers 107, 108, and 109 are configured to be replaceable by opening an opening / closing cover of the main unit 102 (not shown).
[0045]
In the present embodiment, the case where three upper and lower transport rollers are arranged is shown, but the present invention is not limited to this and can be applied regardless of the number of transport rollers. For example, the present invention can also be applied to a case where a single transport roller is used.
[0046]
In this embodiment, the conveyance rollers 107, 108, and 109 arranged on the paper path 106 will be described, but the present invention is not limited to this. Any conveying roller that conveys a sheet and needs to be replaced can be applied to any conveying roller of the electrophotographic recording apparatus 100.
[0047]
The sheet conveyed by the uppermost conveying roller 109 is transferred to the registration roller 111 by the conveying roller 110. A photosensitive drum 112 that rotates in the direction of the arrow in the drawing is disposed at the sheet conveyance destination by the registration roller 111. The photosensitive drum 112 is pivotally supported on its side by the photosensitive drum driving device according to the present embodiment.
[0048]
Above the photosensitive drum 112, an LSU (Laser Scan Unit) 113 that forms a latent image on the surface of the photosensitive drum 112 is disposed. A developing device 114 for adhering developer (toner) to the latent image formed on the photosensitive drum 112 is disposed adjacent to the photosensitive drum 112. The developing device 114 includes a stirring roller that stirs and conveys the developer and a developing roller that adheres the developer to the photosensitive drum 112.
[0049]
Below the photoconductive drum 112, a transfer device 115 is installed for transferring an image formed by the developer adhering to the photoconductive drum 112 onto the conveyed paper. The registration roller 111 controls the position adjustment between the image on the photosensitive drum 112 and the recording area of the paper.
[0050]
A cleaning unit 116 that cleans the surface of the photosensitive drum 112 that has finished transferring the image is disposed adjacent to the photosensitive drum 112. The sheet on which the image has been transferred is further transported by the transport belt 117. A fixing unit 118 is disposed at the conveyance destination of the conveyance belt 117.
[0051]
The fixing unit 118 includes a fixing roller 119, a pressure roller 120 disposed opposite to the fixing roller 119, and a cleaning roller (not shown) for applying oil to improve the releasability of toner remaining on the fixing roller 119. ing. The fixing roller 119 applies heat to the recording surface of the paper, and the pressure roller 120 presses the paper against the fixing roller 119, whereby the image is fixed on the paper.
[0052]
The sheet discharged from the fixing unit 118 is discharged outside the main body unit 102 by the discharge roller 121. The paper discharged from the main unit 102 is received on the paper discharge tray 122.
[0053]
Between the fixing unit 118 and the discharge roller 121, a switching guide 124 for switching whether to discharge the sheet to the outside of the main unit 102 or to send the sheet to the duplex path 123 for performing duplex recording is disposed. The double-sided path 123 is formed in the downward direction from the vicinity of the switching guide 124, and is formed in the substantially horizontal direction in the middle thereof.
[0054]
The sheet fed into the double-sided path 123 is temporarily drawn by the reverse roller 125 into the reverse path 126 formed on the extension of the portion 123A formed in the downward direction of the double-sided path 123. When the sheet is drawn into the reversing path 126, the reversing roller 125 is reversed and feeds the sheet to the portion 123 B formed in the substantially horizontal direction in the double-sided path 123. At this point, the front and back of the paper are reversed.
[0055]
The sheet fed into the double-sided path 123B formed in the substantially horizontal direction is conveyed by the conveyance rollers 127, 128, and 129 formed on the double-sided path 123B. The double-sided path 123 B is connected to the paper path 106 below the conveyance roller 110. The paper that has been transported through the double-sided path 123B by the transport rollers 127, 128, and 129 and sent to the paper path 106 is sent again below the photosensitive drum 112, and an image is formed on the back surface this time.
[0056]
A manual feed tray 130 that realizes paper feeding other than paper feeding from the paper feeding cassette 103 is provided on the side surface of the main unit 102. The uppermost sheet of the stack of sheets placed on the manual feed tray 130 is taken in by the pickup roller 131 and transferred to the registration roller 111 by the transport roller 132.
[0057]
FIG. 2 shows a cross-sectional view of the photosensitive drum driving device according to the present embodiment after assembly, and FIG. 3 shows an exploded perspective view of the photosensitive drum driving device according to the present embodiment.
[0058]
As shown in FIGS. 2 and 3, the photosensitive drum driving device 200 according to the present exemplary embodiment has a photosensitive drum 112 sandwiching an internal housing 201 of the main unit 102 that is disposed to face the side surface of the photosensitive drum 112. It is installed on the other side.
[0059]
The photosensitive drum driving device 200 has a shape that secures a space for housing a motor, which will be described later, and supports the drum driving shaft 202 in the vicinity of the center thereof. When the photosensitive drum driving device 200 is installed, the drum driving shaft 202 passes through a hole 201 A formed at a predetermined position of the internal housing 201 and engages with the side surface of the photosensitive drum 112. When properly engaged, the drum drive shaft 202 is coaxially engaged with the photosensitive drum 112 and rotates integrally with the photosensitive drum 112.
[0060]
The photosensitive drum driving device 200 connects a second sheet metal 204 having a shape opened to the first sheet metal 203 by bending or the like to a planar first sheet metal 203 stacked on the inner casing 201. A certain space is provided inside. The second sheet metal 204 is connected to the first sheet metal 203 by a plane portion 211 parallel to the first sheet metal 203. The connected first sheet metal 203 and second sheet metal 204 (hereinafter referred to as “a pair of sheet metals”) are fixed to the inner housing 201 in a direction from the first sheet metal 203 to the second sheet metal 204. It is fixed by screws 206 from the side opposite to the screws 205. In this embodiment, self-tapping screws are used for the screws 205 and 206.
[0061]
A motor 207 as a drive source of the photosensitive drum 112 is accommodated in the space inside the photosensitive drum driving device 200. The motor 207 is fixed to a predetermined position on the side surface side of the second sheet metal 204 and above the drum drive shaft 202. The drive shaft of the motor 207 passes through a hole 204 A formed at a predetermined position of the second sheet metal 204 and protrudes outside the second sheet metal 204.
[0062]
The peripheral surface of the drive gear 208 attached to the end of the drum drive shaft 202 meshes with the drive shaft of the motor 207. As a result, the power of the motor 207 is transmitted to the drum drive shaft 202 via the drive gear 208.
[0063]
The drum drive shaft 202 has a position corresponding to the hole 201 A formed in the inner housing 201, and includes a hole 203 A formed in the first sheet metal 203 and a hole 204 B formed in the second sheet metal 204. It penetrates (see FIG. 3). The drum drive shaft 202 is rotatably held by bearings 209 and 210 that are fitted in the hole 203A and the hole 204B, respectively.
[0064]
Next, an assembly process of the photosensitive drum driving apparatus 200 according to the present embodiment having the above-described configuration will be described.
[0065]
First, as shown in FIG. 4, the second sheet metal 204 manufactured by pressing or the like with the motor 207 fixed at a predetermined position is aligned with the predetermined position of the first sheet metal 203. At this time, the both are aligned so that the approximate positions of the holes 203A and 204B formed in the first sheet metal 203 and the second sheet metal 204, respectively, are aligned.
[0066]
Next, as shown in FIG. 5, in a state where the first sheet metal 203 and the second sheet metal 204 are combined, the holes 203A and 204B formed in the first sheet metal 203 and the second sheet metal 204 are penetrated. The reference shaft 501 is inserted from the first sheet metal 203 side.
[0067]
Here, the reference axis 501 is an axis that serves as a reference for the parallelism between the first sheet metal 203 and the second sheet metal 204. The reference shaft 501 has a shape that matches the shape of the holes 203A and 204B formed in the first sheet metal 203 and the second sheet metal 204, respectively. In the present embodiment, the holes 203A and 204B have a circular shape with the same size, and the reference shaft 501 has a cylindrical shape with the same thickness. Further, the reference shaft 501 has a peripheral surface that matches the circular shape of the holes 203A and 204B.
[0068]
Note that the reference shaft 501 is provided with a member 502 for restricting insertion of the reference shaft 501 before a certain position during the insertion work for the pair of sheet metals. The member 502 may be integrated with the reference shaft 501 or may be separately attached.
[0069]
By passing such a reference shaft 501 through the holes 203A and 204B, the first sheet metal 203 and the second sheet metal 204 can be aligned in a fixed positional relationship. Further, since the holes are inserted into the holes 203A and 204B having the same shape as the peripheral surface, the reference shaft 501 cannot be inserted unless they are inserted perpendicularly thereto. For this reason, when the reference shaft 501 is inserted, the parallelism of the first sheet metal 203 and the second sheet metal 204 in which the holes 203A and 204B are formed is ensured.
[0070]
The first sheet metal 203 and the second sheet metal 204, which are combined in a certain positional relationship in this way, are fastened with screws 205 in the direction from the first sheet metal 203 to the second sheet metal 204 as shown in FIG. When they are aligned in a fixed positional relationship by the reference shaft 501, a hole 203B into which the screw 205 formed on the first sheet metal 203 is inserted and a hole 204C into which the screw 205 formed on the second sheet metal 204 is inserted. It is arranged at the corresponding position.
[0071]
In the present embodiment, when the work for fixing the screw 205 is performed after the reference shaft 501 is inserted, both work are performed from the same direction. As a result, it is not necessary to move the position of the worker's body or move an object to be assembled. Therefore, it is possible to improve the efficiency of assembling work of the photosensitive drum driving device.
[0072]
FIG. 7 shows an enlarged view of the fastening portion of the screw 205. As shown in FIG. 7, the hole 203B into which the screw 205 formed on the first sheet metal 203 is inserted has a larger diameter than the hole 204C into which the screw 205 formed on the second sheet metal 204 is inserted. ing. The diameter of the hole 203B is smaller than that of the umbrella portion of the screw 205. According to this, even if the hole 204C formed in the second sheet metal 204 is slightly shifted from the hole 203B formed in the first sheet metal 203, the allowable range of the hole 203B formed in the first sheet metal 203 If it is, the 1st sheet metal 203 and the 2nd sheet metal 204 can be fixed reliably. As a result, for example, it is possible to avoid a situation where the screw 205 cannot be inserted, which can occur when the holes formed in the first sheet metal 203 and the second sheet metal 204 have the same size. The fixing operation of the first sheet metal 203 and the second sheet metal 204 can be simplified.
[0073]
If the hole 203B into which the screw 205 is inserted and the hole 204C are set to have the same size, even if the first sheet metal 203 and the second sheet metal 204 are slightly displaced, the screw 205 inserted into the hole 203B. May not coincide with the positions of the holes 204C, and the screw 205 cannot be inserted into these holes. However, if this embodiment is used, the screw 205 can be inserted into the hole 204C if the hole 204C is inside the hole 203B. It can be avoided.
[0074]
Also, by making the hole 203B of the first sheet metal 203 larger than the hole 204C of the second sheet metal 204, for example, when the second sheet metal 204 is produced by bending, the bending accuracy of the second sheet metal 204 is increased. Even if relaxed, the second sheet metal 204 and the first sheet metal 203 are fixed while maintaining the positional relationship between the hole 204B of the second sheet metal 204 and the hole 203A of the first sheet metal into which the drum drive shaft 202 is inserted. In addition, since the bending error of the concave portion of the second sheet metal 204 can be absorbed by the hole 203B of the first sheet metal 203, it is not necessary to increase the processing accuracy of the second sheet metal 204, and the cost can be reduced correspondingly.
[0075]
When the positional relationship between the first sheet metal 203 and the second sheet metal 204 is fixed when the pair of sheet metals has been fastened with the screws 205, the first sheet metal 203 and the second sheet metal 204 are penetrated as shown in FIG. The reference shaft 501 is pulled out. Even when the reference shaft 501 is pulled out, since the positional relationship between the first sheet metal 203 and the second sheet metal 204 is fixed, the parallelism between the first sheet metal 203 and the second sheet metal 204 is maintained.
[0076]
After the reference shaft 501 is pulled out, as shown in FIG. 9, the drum drive shaft 202 with the drive gear 208 attached to one end is inserted from the hole 204 B formed in the second sheet metal 204. At that time, the drum drive shaft 202 is rotatably held by a bearing 210 and a bearing 209 that are fitted in the holes 203A and 204B, respectively.
[0077]
The bearing 210 is attached to a predetermined position of the drum drive shaft 202, and is fitted into the hole 204B in accordance with the insertion of the drum drive shaft 202. On the other hand, the bearing 209 is fitted into the hole 203A from the direction opposite to the insertion direction of the drum drive shaft 202.
[0078]
When the drum drive shaft 202 is inserted to a predetermined position, the peripheral surface of the drive gear 208 meshes with the drive shaft of the motor 207 as shown in FIG. In this way, the drive unit of the photosensitive drum drive device is configured. This time, this drive unit is attached to the internal housing 201.
[0079]
At the time of attachment, one end of the drum drive shaft 202 is inserted into a hole 201 A formed in the internal housing 201. Then, the position is adjusted so that the bearing 209 holding the drum drive shaft 202 is accommodated in the hole 201A. Then, in a state where the first sheet metal 203 and the inner housing 201 are combined, the drive unit is fastened with screws 206 from the first sheet metal 203 side as shown in FIG.
[0080]
When the first sheet metal 203 and the second sheet metal 204 are fixed in this way, both are fixed with screws 205 in the direction from the first sheet metal 203 to the second sheet metal 204, while the second sheet metal 204 is fixed. When the first sheet metal 203 is fixed to the internal housing 201, the first sheet metal 203 is fixed with screws 206 in a direction from the second sheet metal 204 to the first sheet metal 203. Thus, by setting the fixing directions of the screws 205 and 206 to be opposite directions, it is possible to reliably determine which member is fixed by which screw. Therefore, it is possible to reliably avoid a situation where another screw is mistakenly removed when it is necessary to remove one of the screws for some reason after the assembly work of the photosensitive drum driving device is completed.
[0081]
FIG. 11 shows an enlarged view around the fastening portion of the screw 206. As shown in FIG. 11, the hole 203C into which the screw 206 formed in the first sheet metal 203 is inserted has a larger diameter than the hole 201B into which the screw 206 formed in the internal housing 201 is inserted. ing. The diameter of the hole 203C is smaller than the diameter of the umbrella portion of the screw 206. The size relationship between the hole 203C and the hole 201B is the same as the size relationship between the hole 203B into which the screw 205 is inserted and the hole 204C.
[0082]
The inner casing 201 is formed with a hole 201 C that accommodates the umbrella portion of the screw 205 protruding from the first sheet metal 203. Even when the first sheet metal 203 is aligned with the inner casing 201, the umbrella portion of the screw 205 enters the hole 201C. For this reason, the umbrella portion of the screw 205 protruding from the first sheet metal 203 does not hinder the drive unit mounting operation.
[0083]
When the drive unit is fixed to the internal casing 201 with the screw 206, finally, as shown in FIG. 12, the photosensitive drum 112 is engaged with the drum drive shaft 202 protruding to the inside of the internal casing 201. In this way, the assembly process of the photosensitive drum driving device 200 is completed.
[0084]
As described above, according to the method for assembling the photosensitive drum driving device of the present embodiment, the first sheet metal and the second metal plate are used with the reference member inserted into the first hole portion and the second hole portion. Both are fixed while maintaining parallelism with the sheet metal. Further, a drive shaft that is coaxially engaged with the photosensitive drum is inserted into the first hole and the second hole formed in each of the first sheet metal and the second sheet metal fixed in a state where the parallelism is maintained. The According to this, since the first sheet metal and the second sheet metal are fixed while the reference shaft is inserted into the first hole and the second hole in which the drum drive shaft is inserted, the first hole and the second hole are fixed. The coaxiality with the hole is reliably maintained, and the parallelism between the first sheet metal and the second sheet metal is ensured. A drum drive shaft is inserted into the first hole and the second hole, and the photosensitive drum is engaged with the drum drive shaft. For this reason, the axial parallelism between the photosensitive drum and the drum drive shaft is appropriately maintained, and the constant speed rotation motion of the motor is transmitted to the photosensitive drum as the non-uniform speed rotation motion, resulting in uneven rotation. This situation can be avoided reliably.
[0085]
Moreover, when securing the parallelism between the first sheet metal and the second sheet metal, the reference member is fixed while being inserted into the first hole and the second hole formed respectively. For this reason, it is not necessary to produce a reference axis which has a highly accurate length and needs to guarantee the perpendicularity to the one sheet metal as in the prior art. Therefore, it is possible to avoid an increase in the unit cost due to an increase in manufacturing man-hours and the like, thereby preventing an increase in product cost.
[0086]
【The invention's effect】
As described above, according to the present invention, it is possible to reliably prevent problems caused by the positional relationship between the drum drive shaft and the photosensitive drum while preventing an increase in product cost.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an electrophotographic recording apparatus to which a photosensitive drum driving device according to an embodiment of the present invention is applied.
FIG. 2 is a cross-sectional view after assembly of the photosensitive drum driving device according to the embodiment.
FIG. 3 is an exploded perspective view of the photosensitive drum driving device according to the embodiment.
FIG. 4 is a cross-sectional view of an assembly process of the photosensitive drum driving device according to the embodiment.
FIG. 5 is a cross-sectional view of an assembly process of the photosensitive drum driving device according to the embodiment.
FIG. 6 is a cross-sectional view of an assembly process of the photosensitive drum driving device according to the embodiment.
FIG. 7 is an enlarged view of a screw fastening portion for fastening the first sheet metal to the second sheet metal in the photosensitive drum driving apparatus according to the embodiment.
FIG. 8 is a sectional view of an assembling process of the photosensitive drum driving device according to the embodiment.
FIG. 9 is a cross-sectional view of an assembly process of the photosensitive drum driving device according to the embodiment.
FIG. 10 is a cross-sectional view of an assembly process of the photosensitive drum driving device according to the embodiment.
FIG. 11 is an enlarged view of the vicinity of a screw fastening portion for fastening the first sheet metal to the internal housing in the photosensitive drum driving device according to the embodiment.
FIG. 12 is a cross-sectional view of an assembly process of the photosensitive drum driving device according to the embodiment.
FIG. 13 is a cross-sectional view showing a configuration of a conventional photosensitive drum driving device.
FIG. 14 is a sectional view of an assembling process of a conventional photosensitive drum driving device.
FIG. 15 is a sectional view of an assembling process of a conventional photosensitive drum driving device.
FIG. 16 is a sectional view of an assembling process of a conventional photosensitive drum driving device.
FIG. 17 is a sectional view of an assembling process of a conventional photosensitive drum driving device.
FIG. 18 is a sectional view of an assembling process of a conventional photosensitive drum driving device.
FIG. 19 is a diagram showing a state in which the second sheet metal is fixed to the first sheet metal without being properly bent in the conventional photosensitive drum driving device.
20 is an enlarged view around the inserted drum drive shaft in the state shown in FIG. 19;
[Explanation of symbols]
100 Electrophotographic recording apparatus
101 Reading unit
102 Main unit
107-109 Transport roller
201 Internal housing
202 Drum drive shaft
203 1st sheet metal
204 Second sheet metal
205,206 screw
207 motor
208 Drive gear
209,210 Bearing
501 Reference axis

Claims

A drive shaft that is coaxially engaged with the photosensitive drum, a planar first sheet metal having a first hole through which the drive shaft passes, a planar section coupled to the first sheet metal, and the first sheet metal A recess that is open and has a recess in which the drive system for driving the drive shaft is housed and the plane of the recess that is parallel to the first sheet metal when the plane is coupled to the first sheet metal. A second sheet metal having a second hole portion through which the drive shaft is passed, and a first metal hole having the same shape and the same size as the shaft peripheral surface and inserted vertically through the second hole portion . In this case, the first sheet metal having the first hole portion is provided with a member for restricting that one end portion protrudes from the second hole portion and the other end portion is inserted before the position of the first hole portion. plane as the said second bore portion and said first hole with parallelism between the second sheet metal plane having a second bore portion of the The A method of assembling a photoreceptor drum driving apparatus comprising a reference axis as a reference to form a coaxial, and said shaft of said reference axis in a state in which first combined and the second sheet metal and the first sheet metal A first step of vertically penetrating and inserting into the first hole and the second hole having the same shape and the same size as the peripheral surface, and a first step having the first hole with reference to the reference axis . The first fixing is performed while maintaining the parallelism between the plane of the first sheet metal and the plane of the second sheet metal having the second hole portion and that the first hole portion and the second hole portion are coaxial. A second step, a third step of removing the reference shaft from the first hole and the second hole, and a fourth step of inserting the drive shaft into the first hole and the second hole. And a method for assembling the photosensitive drum driving device.

A drive shaft that is coaxially engaged with the photosensitive drum, a planar first sheet metal having a first hole through which the drive shaft passes, a planar section coupled to the first sheet metal, and the first sheet metal A recess that is open and has a recess in which the drive system for driving the drive shaft is housed and the plane of the recess that is parallel to the first sheet metal when the plane is coupled to the first sheet metal. a second metal plate having a second hole through which the drive shaft above, when inserted through toward the second hole from the axis of the peripheral surface the same shape and the same size of the first hole portion , a member for restricting the one end and the other end portion together with the projects from the second hole portion is inserted before the first hole portion position is provided, the plane of the first sheet metal having a first bore portion the said first hole with parallelism between the second sheet metal plane having the second hole and the second hole portion same as A method of assembling a photoreceptor drum driving apparatus comprising a reference axis as a reference to form above a first shaft circumferential surface the reference axis in a state of combining the said second sheet metal and the first sheet metal A first sheet metal having the same shape and the same size as the first hole portion and the first hole portion vertically penetrating and inserted into the second hole portion, and then having the first hole portion on the basis of the reference axis The first sheet metal from the first sheet metal while maintaining the parallelism between the plane of the second sheet metal and the plane of the second sheet metal having the second hole, and maintaining that the first hole and the second hole are coaxial. A second step of fixing both with a first screw in a direction toward the two sheet metal, a third step of removing the reference shaft from the first hole and the second hole, and then the first hole. A fourth step of inserting the drive shaft into the first hole and the second hole, and then the direction from the second sheet metal to the first sheet metal Fifth Step and method of assembling a photoreceptor drum driving apparatus characterized by comprising for securing the second screw the first sheet metal to the apparatus main body.

3. A screw hole formed in the first sheet metal used for fixing to the second sheet metal is larger than a screw hole formed in a flat portion obtained by bending the second sheet metal end portion by one diffraction. A method for assembling the photosensitive drum driving device according to claim 1.

4. The method for assembling a photosensitive drum driving device according to claim 2, wherein the reference shaft is inserted in the same direction as the first screw is fixed.

A drive shaft that is coaxially engaged with the photosensitive drum, a planar first sheet metal having a first hole through which the drive shaft passes, a planar section coupled to the first sheet metal, and the first sheet metal A recess that is open and has a recess in which the drive system for driving the drive shaft is housed and the plane of the recess that is parallel to the first sheet metal when the plane is coupled to the first sheet metal. When the second sheet metal having the second hole portion through which the drive shaft passes is inserted and inserted through the first hole portion having the same shape and the same size as the shaft peripheral surface toward the second hole portion. The first sheet metal plane having the first hole portion is provided with a member for restricting one end portion protruding from the second hole portion and the other end portion from being inserted before the position of the first hole portion. the said first hole with parallelism between the second sheet metal plane having the second hole and the second hole portion same as An assembly method of an electrophotographic recording apparatus comprising a reference axis as a reference formed above, wherein the reference axis is set to the shaft peripheral surface in a state where the first sheet metal and the second sheet metal are first combined. A first step of vertically inserting the first hole and the second hole of the same shape and the same size, and then the first sheet metal having the first hole with reference to the reference axis A second step of fixing both the plane and the plane of the second sheet metal having the second hole part, while maintaining the parallelism between the plane and the first hole part and the second hole part being coaxial. Then, a third step of removing the reference shaft from the first hole and the second hole, and a fourth step of inserting the drive shaft into the first hole and the second hole, An assembly method for an electrophotographic recording apparatus comprising: