JP2004286506A

JP2004286506A - Friction evaluating device and friction evaluating method

Info

Publication number: JP2004286506A
Application number: JP2003077195A
Authority: JP
Inventors: Tetsuya Sonoda; 徹也園田
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2003-03-20
Filing date: 2003-03-20
Publication date: 2004-10-14

Abstract

<P>PROBLEM TO BE SOLVED: To highly accurately evaluate friction characteristics (friction coefficient and slip load) between a rotating body and a belt body, such as a photoreceptor drum and a transfer belt, of a copying machine or a printer. <P>SOLUTION: The belt body 2, being kept in contact with the rotating body 1, is held by a belt-body holding part 3. The rotating body 1 is rotatively driven by a rotating-body drive part 4. A tight-side load of the belt body 2 is measured via the holding part 3 by a belt tight-side tensile load measurement part 5. A loose-side load of the belt body 2 is detected via the holding part 3 by a belt loose-side tensile load measurement part 6. A rotating-body friction evaluation part 11, such as a microcomputer, calculates a friction coefficient and a slip load based on the tight-side load, the loose-side load, and an evaluation expression. The setting of a contact angle of the rotating body 1 with the belt body 2 is facilitated by allowing the measurement parts 5 and 6 to make vertical or turning motion. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、例えば、複写機またはプリンタ内に搭載されている感光体ドラム−転写ベルト間のスリップ負荷の評価など、ベルトとドラム間で発生するスリップ負荷および摩擦係数などの摩擦特性の評価値を測定する摩擦評価装置及び摩擦評価方法に関する。
【０００２】
【従来の技術】
従来、プーリに測定したい巻付け角度でベルトを巻き付け、前記ベルトの一端を荷重検出器に取り付けた状態で他端部に引張力を加え、この状態でプーリに回転駆動を加えるようにしてベルトとプーリ間の摩擦力を測定する装置がある。例えば、特開平９−２４３４８２号公報に開示されてる技術では、プーリと、前記プーリと同一回転中心で回動可能な検出器取付ジグを具備し、荷重検出器は検出器取付ジグに固定配置してある。検出器取付ジグは、固定ブレーキにより回動・回動不能状態にできるようにしてある。
【０００３】
この摩擦力の測定装置では、検出器取付ジグを回転させると巻付け角度は変化するが、前記検出器取付ジグはプーリと同一回転中心で回動可能なものとしてあるから、ベルトのプーリの巻き付け端から荷重検出器からまでのベルトの長さＬは変化しない。したがって、巻付け角度が変化しても同一条件下での摩擦力の測定が可能となる。また、ベルトの振れにより、真の巻付け角度はたえず変化しているが、検出器取付ジグを回動可能状態して測定途中に回動させることにより、巻付け角度が変化する場合の摩擦力（静止摩擦力を含む）の変化を測定することも可能である。
【０００４】
【特許文献１】
特開平９−２４３４８２号公報
【０００５】
【発明が解決しようとする課題】
ここで、ベルト−プーリ間の摩擦力は、ベルト両端のベルト張力により決定される。ベルトの一端の張力をＴ１、他端の張力をＴ２とすると、摩擦力Ｐは、下記式により表せる。
Ｐ＝Ｔ１−Ｔ２ …（１）
【０００６】
特開平９−２４３４８２号公報の「摩擦力の測定装置」では、ベルトの他端のベルト張力が常に一定であるという条件を基に、他端のベルト張力の変動量ΔＴ２を摩擦力Ｐと等価であると見なして計測している。つまり、プーリを回転させる前はＰ＝０であるから、重りの重量をＷ、荷重検出器側のベルト張力をＴｓとすると前式（１）により、
Ｗ＝Ｔｓ …（２）
また、プーリ回転時の摩擦力をＰｓ、荷重検出器側のベルト張力をＴｓ′とすると、プーリ回転時は、
Ｗ＋Ｐｓ＝Ｔｓ′ …（３）
であり、よって、
Ｐｓ＝Ｔｓ′−Ｗ＝Ｔｓ′−Ｔｓ …（４）
となり、Ｔｓ′−Ｔｓ、つまり荷重検出器側のベルト張力変動量が摩擦力Ｐｓと等価になる。
また、理論的にはベルト張力と接触角度（ベルトと回転体との接触部分の角度）により、下記式５を用いて摩擦係数を評価することができる。
μ＝ｌｎ（Ｔ３／Ｔ４）／θ …（５）
ここで、μ：摩擦係数、Ｔ３：張り側ベルト張力、Ｔ４：ゆるみ側ベルト張力、θ：接触角度
【０００７】
しかし、特開平９−２４３４８２号公報の「摩擦力の測定装置」の方法では、プーリにベルトを装着する際に、静摩擦力を発生させずに装着させることが困難であるため、前式（２）のように初期のベルト張力と重りの荷重とを正確に一致させることは難しく、摩擦特性を高精度に評価することが困難である。
【０００８】
本発明は、ベルト両端に荷重検出器を装着することでベルト両端のベルト張力を評価することで、摩擦特性（摩擦係数やスリップ負荷）を高精度に評価することを課題とする。
【０００９】
【課題を解決するための手段】
請求項１の摩擦評価装置は、回転体と、ベルト体と、前記ベルト体を前記回転体に接触させた状態で前記ベルト体を保持するベルト体保持手段と、前記回転体を回転駆動する回転体駆動手段と、前記ベルト体の引張り荷重を計測するベルト引張り荷重計測手段と、前記引張り荷重計測手段により計測したベルト引張り荷重と、評価式を基に摩擦特性の評価値を算出する摩擦特性評価値算出手段と、を有し、前記回転体駆動手段により前記回転体を回転駆動させ、前記引張り荷重計測手段により計測した、前記回転体と前記ベルト体間で発生するベルト引張り荷重を基に、前記回転体と前記ベルト体間の摩擦評価値を算出する摩擦評価装置において、前記ベルト引張り荷重計測手段は、前記ベルト体の張り側の荷重を計測するベルト張り側引張り荷重計測手段と、前記ベルト体のゆるみ側の荷重を検出するベルトゆるみ側引張り荷重計測手段とを備え、前記摩擦特性評価値算出手段は、前記ベルト張り側引張り荷重計測手段により計測したベルト張り側引張り荷重と、前記ベルトゆるみ側引張り荷重計測手段により計測したベルトゆるみ側引張り荷重と、評価式と、を基に、前記回転体と前記ベルト体間の摩擦特性の評価値を算出することを特徴とする。
【００１０】
請求項２の摩擦評価装置は、請求項１に記載の摩擦評価装置において、前記摩擦特性評価値算出手段は、前記ベルト張り側引張り荷重と前記ベルトゆるみ側引張り荷重との比と、前記回転体と前記ベルト体との接触角度を基に、前記摩擦特性の評価値として前記回転体と前記ベルト体間の摩擦係数を算出することを特徴とする。
【００１１】
請求項３の摩擦評価装置は、請求項１に記載の摩擦評価装置において、前記回転体摩擦評価値算出手段は、前記ベルト張り側引張り荷重と前記ベルトゆるみ側荷重との差より、前記摩擦特性の評価値として前記回転体と前記ベルト体間に発生するスリップ負荷を算出することを特徴とする。
【００１２】
請求項４の摩擦計測装置は、請求項１に記載の摩擦評価装置において、前記ベルト体の張り側の荷重を計測するベルト張り側引張り荷重計測部と、前記ベルト体のゆるみ側の荷重を計測するベルトゆるみ側引張り荷重計測部と、を移動可能としたベルト引張り荷重計測移動手段を有することを特徴とする。
【００１３】
請求項５の摩擦評価装置は、請求項４に記載の摩擦評価装置において、前記ベルト引張り荷重計測移動部の位置を検出するベルト引張り荷重計測移動位置検出手段を有することを特徴とする。
【００１４】
請求項６の摩擦評価装置は、請求項４に記載の摩擦評価装置において、前記回転体の軸方向に対し、前記ベルト張り側引張り荷重計測部と、前記ベルトゆるみ側引張り荷重計測部とを、それぞれ回転自由に保持する計測部回転自由保持手段を有することを特徴とする。
【００１５】
請求項７の摩擦評価装置は、請求項１に記載の摩擦評価装置において、前記ベルト体保持手段は、前記ベルト体を回転自由に保持するベルト体回転自由保持手段を有することを特徴とする。
【００１６】
請求項８の摩擦評価装置は、請求項１に記載の摩擦評価装置において、前記回転体に対し前記ベルト体を介して対向の位置に帯電体を設け、前記回転体と前記帯電体との間に電位差を発生させる電位差発生手段を有することを特徴とする。
【００１７】
請求項９の摩擦評価方法は、回転体とベルト体とを対象として、前記ベルト体を前記回転体に接触させた状態で前記ベルト体を保持するベルト体保持工程と、前記回転体を回転駆動する回転体駆動工程と、前記ベルト体の引張り荷重を計測するベルト引張り荷重計測工程と、前記ベルト引張り荷重計測工程により計測したベルト引張り荷重と、評価式を基に摩擦特性の評価値を算出する摩擦特性評価値算出工程と、を有し、前記回転体駆動工程により前記回転体を回転駆動させ、前記ベルト引張り荷重計測工程により計測した、前記回転体と前記ベルト体間で発生するベルト引張り荷重を基に、前記回転体と前記ベルト体間の摩擦評価値を算出する摩擦評価方法において、前記ベルト引張り荷重計測工程は、前記ベルト体の張り側の荷重を計測するベルト張り側引張り荷重計測工程と、前記ベルト体のゆるみ側の荷重を検出するベルトゆるみ側引張り荷重計測工程とからなり、前記摩擦特性評価値算出工程は、前記ベルト張り側引張り荷重計測工程により計測したベルト張り側引張り荷重と、前記ベルトゆるみ側引張り荷重計測工程により計測したベルトゆるみ側引張り荷重と、評価式と、を基に、前記回転体と前記ベルト体間の摩擦特性の評価値を算出することを特徴とする。
【００１８】
【発明の実施の形態】
以下、本発明の実施形態について図面を参照して説明する。図１は実施形態の摩擦評価装置の全体構成を示す図である。なお、図１において、図２〜図６等に示した詳細な構成は図示を省略してある。
【００１９】
［請求項１に対応する具体的構成］（図１、図２、図３）
実施形態の摩擦評価装置は、評価対象である回転体１およびベルト体２と、このベルト体２を回転体１に接触させた状態でこのベルト体２を保持するベルト体保持部３と、回転体１を回転駆動する回転体駆動部４と、一方のベルト体保持部３を介してベルト体２の張り側の荷重を計測するベルト張り側引張り荷重計測部５と、他方のベルト体保持部３を介してベルト体２のゆるみ側の荷重を検出するベルトゆるみ側引張り荷重計測部６と、ベルト張り側引張り荷重計測部５およびベルトゆるみ側引張り荷重検出部６を保持する引張り荷重計測保持部１４と、回転体１とベルト体２間の摩擦状態の評価値を算出する回転体摩擦評価部１１とにより構成されている。
【００２０】
前記ベルト体保持部３は、例えば図２のように、前記ベルト体２をゴム部材７で挟み、さらに金属板８で挟んだ後、ボルト９およびナット１０で締め付けるように構成されている。前記回転体駆動部４は例えばモータを用いる。前記ベルト張り側引張り荷重計測部５および前記ベルトゆるみ側引張り荷重計測部６は、例えばフォースゲージを用いる。前記回転体摩擦評価部１１は、例えばベルト張り側引張り荷重計測部５およびベルトゆるみ側引張り荷重計測部６より計測した引張り荷重データのインターフェイスを持つパソコンを用いる。
【００２１】
前記引張り荷重検出部保持部１４は、図３のように、前記ベルトゆるみ側荷重計測部６をスライダー部１５に図の左右方向に摺動自在に固定し、このスライダー部１５をスライダーベース部１６に固定するように構成されている。ベルトゆるみ側荷重計測部６は、ネジを切った棒部材１７に固定し、ナット１８を回転させることでベルトゆるみ側引張り荷重計測部６が移動するように構成されている。なお、前記ベルト引張り側引張り荷重計測部５についても同様に構成されている。
【００２２】
ベルト体保持部３は「ベルト体保持手段」に対応し、回転体駆動部４は「回転体駆動手段」に対応する。また、ベルト張り側引張り荷重計測部５は「ベルト張り側引張り荷重検出手段」に対応し、ベルトゆるみ側引張り荷重計測部６は「ベルトゆるみ側引張り荷重検出手段」に対応し、このベルト張り側引張り荷重計測部５とベルトゆるみ側引張り荷重計測部６が、「ベルト引張り荷重計測手段」に対応する。
【００２３】
以上の構成により次のように動作する。前記ベルト体保持部３は、ベルト体２を回転体１に接触させるようにベルト体２の端部を保持する。ベルト張り側引っ張り荷重計測部５、およびベルトゆるみ側荷重計測部６の両者をナット１８を回転させることでベルト引っ張り方向に移動し、ベルト体２に対して任意のベルト張力を発生させる。次に、回転体駆動部４により回転体１を任意の速度で回転させ、ベルト体２の張り側の荷重（ベルト張り側引張り荷重）をベルト張り側引張り荷重計測部５で計測する。また、ベルト体２のゆるみ側の荷重（ベルトゆるみ側引張り荷重）をベルトゆるみ側引張り荷重計測部６で計測する。そして、後述のように、回転体摩擦評価部１１で、張り側の荷重、ゆるみ側の荷重及び評価式により、摩擦係数を算出する。
【００２４】
［請求項２に対応する具体的構成］（図１）
請求項２に対応して、前記回転体摩擦評価部１１は、前式（５）の摩擦係数算出式に基づく演算が可能な機能を持つ回転体摩擦係数算出部１２を備えている。この回転体摩擦係数算出部１２は、さらに具体的にはマイコンのＣＰＵが演算プログラムを実行する機能として構成される。
【００２５】
回転体摩擦係数算出部１２は、ベルト張り側引張り荷重計測部５で計測した前記張り側の荷重のデータと、ベルトゆるみ側引張り荷重計測部６で計測した前記ゆるみ側の荷重のデータと、例えば予め手入力された接触角度のデータを入力し、前式（５）の理論式を基に摩擦係数を算出する。そして、回転体摩擦評価部１１は、摩擦係数を例えば図示しないディスプレイ等に出力するよう動作する。
【００２６】
［請求項３に対応する具体的構成］
前記回転体摩擦評価部１１は、前式（１）のスリップ負荷算出式に基づく演算が可能な機能を持つスリップ負荷算出部１３を備えている。このスリップ負荷算出部１３は、さらに具体的にはマイコンのＣＰＵが演算プログラムを実行する機能として構成される。
【００２７】
スリップ負荷算出部１３は、ベルト張り側引張り荷重計測部５で計測した前記張り側の荷重のデータと、ベルトゆるみ側引張り荷重計測部６で計測した前記ゆるみ側の荷重のデータとを入力し、前式（１）の理論式を基にスリップ負荷を算出する。そして、回転体摩擦評価部１１は、スリップ負荷を例えば図示しないディスプレイ等に出力するよう動作する。
【００２８】
［請求項４に対応する具体的構成］（図１，図３）
図１の摩擦評価装置は、前記ベルト体２の張り側の荷重を計測するベルト張り側引張り荷重計測部５と、前記ベルト体２のゆるみ側の荷重を計測するベルトゆるみ側引張り荷重計測部６とを移動可能としたベルト引張り荷重計測移動部２２により構成されている。このベルト引張り荷重計測移動部２２は、前記回転体１の中心軸に対し直交する方向（垂直方向）に、任意の高さにガイド２３に沿って移動可能とする。そして、任意の高さに設定後クランプ部（図示せず）により固定するように動作する。なお、ベルト引張り荷重計測移動部２２は「ベルト引張り荷重計測移動手段」に対応する。
【００２９】
［請求項５に対応する具体的構成］（図３）
図３のように、前記ベルト引張り荷重計測部移動部２２にベルト引張り荷重計測移動位置検出部１９を配置するように構成にされており、このベルト引張り荷重計測移動位置検出部１９は、例えばリニアーエンコーダで構成する。または、レーザー測長器を前記ベルト引張り荷重計測部移動部２２に配置するように構成してもよい。ベルト引張り荷重計測移動位置検出部１−１９あるいは図示しないレーザー測長器は「ベルト引張り荷重計測移動位置検出手段」に対応する。
【００３０】
ベルト引張り荷重計測移動位置検出部１９は、前記ベルト引張り荷重計測移動部２２の位置を検出し、その情報を出力するように動作する。例えば、図４に示すように、回転体１の軸からベルト引張り荷重計測移動部２２上のベルト張り側引張り荷重計測部５の回動軸Ｏを通る鉛直線までの距離（既知の値）をＬ、回転体１の半径（既知の値）をＲとすると、ベルト張り側の接触角度をα／２に設定したい場合、回転体１の軸位置からベルト張り側引張り荷重計測部５の回動軸Ｏまでの高さｘをベルト引張り荷重計測移動部２２の位置から割り出し、これらのＬ、Ｒ、ｘを下式（６）に代入して、逆算することにより、接触角度α／２を設定することができる。
ｘ＝（Ｌ−Ｒｓｉｎ（α／２））ｔａｎ（α／２）−Ｒｃｏｓ（α／２） …（６）
【００３１】
［請求項６に対応する具体的構成］（図３）
前記ベルト張り側引張り荷重計測部５と、前記ベルトゆるみ側引張り荷重計測部６を、前記回転体１の中心軸と平行な軸に対して回転自由に保持した計測部回転自由保持部２４を用いて構成されている。例えば、図３のように、前記スライダーベース部１６に軸１６ａ（軸の方向は図面に対して直角な方向）を設け、軸受け２１により保持する。なお、ベルト引張り側引張り荷重計測部５についても同様に構成されている。これにより、ベルト体２を装着し、ベルト張り側引張り荷重計測部５およびベルトゆるみ側引張り荷重計測部６を移動した際に、ベルト体２に発生した引張り張力により、ベルト張り側引張り荷重計測部５およびベルトゆるみ側引張り荷重計測部６がその荷重検出方向がベルト引張り荷重方向に向くように動作する。計測中に、ベルト張り側引張り荷重計測部５およびベルトゆるみ側引張り荷重計測部６廻りのアンバランスにより回転方向に振動する場合は、クランプ部（図示せず）により計測部回転自由保持部２４を固定することが望ましい。
【００３２】
［請求項７に対応する具体的構成］（図５）
前記ベルト体保持部３を、前記ベルト張り側引張り荷重計測部５および前記ベルトゆるみ側引張り荷重計測部６に対して回転自由に固定するベルト体回転自由保持部２５を用いて構成されている。例えば、図５のように、ベルト体保持部３の中央に取付金具２６を設け、前記ベルト張り側引張り荷重計測部５または前記ベルトゆるみ側引張り荷重計測部６に装着された取付フック２７を前記取付金具２６に引っかける。これにより、ベルト体２を装着し、前記ベルト張り側引張り荷重計測部５および前記ベルトゆるみ側引張り荷重計測部６およびを移動した際に、ベルト体２に発生する引張り張力分布によって、ベルト体保持部３が回転するように動作し、ベルト張力分布が均一になる。
【００３３】
［請求項８に対応する具体的構成］（図６）
図６に示したように、回転体１に対しベルト体２を介して対向する位置に帯電体として例えば帯電ブラシ２８を設け、回転体１と帯電ブラシ２８を電圧発生装置３０に接続するように構成する。そして、電圧発生装置３０により電圧を掛けて、回転体１と帯電ブラシ２８との間に電位差を発生させるように動作する。これにより、電位差による静電気発生位置での摩擦評価が可能になる。
【００３４】
複写機、プリンタの電写真プロセスの場合、感光体ドラムに現像されたトナーを転写ベルトにバイアス電圧により転写することが一般的に行われている。このため、感光体ドラムと転写ベルト間のスリップ負荷を評価するためには、バイアス電圧を掛けた状態での計測が必要である。前記特開平９−２４３４８２号公報の方法では、バイアス電圧を掛ける装置を容易に装着可能であるが、接触角度毎にバイアス電圧を掛ける装置を移動する機構が必要であるが、上記実施形態（請求項８）では、ベルト両端のベルト固定位置を変更することで接触角度を設定しているので、バイアス電圧を掛けた状態でのスリップ負荷および摩擦係数を容易に測定することができる。
【００３５】
［評価結果］
実施形態の摩擦評価装置を用いて評価した、感光体ドラムおよび転写ベルト間の摩擦係数を図７に、スリップ負荷を図８にそれぞれ示す。摩擦係数ではトナーが付着した際に摩擦係数が小さくなることを定量的に評価することができた。また、感光体ドラムと転写ベルト間の界面の変化による、感光体ドラム１回転周期での摩擦係数の変動を捕らえることができるようになった。また、電位差による静電力によって転写ベルトと感光体ドラム間の巻き付け力の増大により、スリップ負荷が増加する傾向を捕らえることができるようになった。
【００３６】
【発明の効果】
請求項１の摩擦評価装置及び請求項９の摩擦評価方法によれば、ベルト体の張り側引張り荷重と、ゆるみ側引張り荷重を同時に計測できるので、ベルト体を装着時に張り側張力とゆるみ側張力の計測値により、任意の初期ベルト引張り荷重を正確に設定することができ、摩擦特性（摩擦係数やスリップ負荷）を高精度に評価することができる。
【００３７】
請求項２の摩擦評価装置によれば、ベルト体の張り側引張り荷重とゆるみ側引張り荷重の比が求まるので、正確な摩擦係数を評価することができる。
【００３８】
請求項３の摩擦評価装置によれば、ベルト体の張り側引張り荷重とゆるみ側引張り荷重の差が求まるので、正確なスリップ負荷を評価することができる。
【００３９】
請求項４の摩擦評価装置によれば、ベルト引張り荷重計測部を任意の位置に設定可能になるので、任意の接触角度を設定することができる。
【００４０】
請求項５の摩擦評価装置によれば、ベルト引張り荷重計測部を任意の位置に正確に設定可能になるので、任意の接触角度を正確に設定することができる。
【００４１】
請求項６の摩擦評価装置によれば、ベルト体の初期ベルト引張り荷重を設定する際に、ベルト引張り荷重計測部がベルト引張り荷重方向に正確に向くようになるため、任意の接触角度を正確に設定することができる。また、ベルト引張り荷重を正確に計測することができる。
【００４２】
請求項７の摩擦評価装置によれば、ベルト体のベルト張力分布によりベルト体保持部が不均一なベルト張力分布を緩和するようになるため、ベルト体の引張り荷重による回転体への押し当て力が回転体の軸方向に対して均一に負荷することができる。また、ベルト体保持部を一点で支えているため、全体のベルト体引張り荷重を正確に計測できる。
【００４３】
請求項８の摩擦評価装置によれば、移動可能なベルト引張り荷重計測部と帯電体とで構成しているため、帯電体を移動することなく任意の接触角度と、電位差による静電気発生位置での摩擦評価が可能になる。
【図面の簡単な説明】
【図１】本発明の実施形態の摩擦評価装置の全体構成を示す図である。
【図２】本発明の実施形態における前記ベルト体保持部の一例を示す図である。
【図３】本発明の実施形態における引張り荷重検出部保持部、ベルト引張り荷重計測部移動部及び計測部回転自由保持部の一例を示す図である。
【図４】本発明の実施形態における接触角度と荷重計測移動部の位置との関係を説明する図である。
【図５】本発明の実施形態におけるベルト体回転自由保持部の一例を示す図である。
【図６】本発明の実施形態における帯電体を設けた例を説明する図である。
【図７】本発明の実施形態の摩擦評価装置を用いて評価した摩擦係数の評価例を示す図である。
【図８】本発明の実施形態の摩擦評価装置を用いて評価したスリップ負荷の評価例を示す図である。
【符号の説明】
１回転体
２ベルト体
３ベルト体保持部
４回転体駆動部
５ベルト張り側引張り荷重計測部
６ベルトゆるみ側引張り荷重計測部
１１回転体摩擦評価部[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention provides, for example, evaluation of slip characteristics between a belt and a drum, such as evaluation of a slip load between a photosensitive drum and a transfer belt mounted in a copying machine or a printer, and evaluation values of friction characteristics such as a friction coefficient. The present invention relates to a friction evaluation device and a friction evaluation method for measuring.
[0002]
[Prior art]
Conventionally, a belt is wound around a pulling angle to be measured on a pulley, a pulling force is applied to the other end of the belt while one end of the belt is attached to a load detector, and a rotational drive is applied to the pulley in this state to form a belt. There is a device for measuring the frictional force between pulleys. For example, in the technique disclosed in Japanese Patent Application Laid-Open No. 9-243482, a pulley and a detector mounting jig rotatable about the same rotation center as the pulley are provided, and the load detector is fixedly disposed on the detector mounting jig. It is. The detector mounting jig is configured to be able to be turned or not turned by a fixed brake.
[0003]
In this frictional force measuring device, when the detector mounting jig is rotated, the winding angle changes. However, since the detector mounting jig is configured to be rotatable about the same rotation center as the pulley, the winding of the belt pulley is performed. The length L of the belt from the end to the load detector does not change. Therefore, even if the winding angle changes, the friction force can be measured under the same conditions. In addition, the true wrapping angle is constantly changing due to the runout of the belt, but the frictional force when the wrapping angle is changed by rotating the detector mounting jig in the rotatable state during the measurement is measured. It is also possible to measure changes in (including static friction).
[0004]
[Patent Document 1]
JP-A-9-243482
[Problems to be solved by the invention]
Here, the frictional force between the belt and the pulley is determined by the belt tension at both ends of the belt. Assuming that the tension at one end of the belt is T1 and the tension at the other end is T2, the frictional force P can be expressed by the following equation.
P = T1-T2 (1)
[0006]
Japanese Patent Application Laid-Open No. 9-243482 discloses a "measuring device for frictional force", in which the fluctuation amount .DELTA.T2 of the belt tension at the other end is equivalent to the frictional force P based on the condition that the belt tension at the other end of the belt is always constant. Is measured assuming that That is, since P = 0 before the pulley is rotated, if the weight of the weight is W and the belt tension on the load detector side is Ts, the following equation (1) is used.
W = Ts (2)
When the frictional force at the time of pulley rotation is Ps and the belt tension at the load detector side is Ts', at the time of pulley rotation,
W + Ps = Ts' (3)
So,
Ps = Ts'-W = Ts'-Ts (4)
Ts′−Ts, that is, the amount of belt tension fluctuation on the load detector side becomes equivalent to the frictional force Ps.
Also, theoretically, the coefficient of friction can be evaluated using the following equation 5 based on the belt tension and the contact angle (the angle of the contact portion between the belt and the rotating body).
μ = ln (T3 / T4) / θ (5)
Here, μ: friction coefficient, T3: tension on the tension side belt, T4: tension on the loose side belt, θ: contact angle
However, in the method of the "measuring device for frictional force" disclosed in JP-A-9-243482, it is difficult to attach the belt to the pulley without generating a static frictional force when attaching the belt to the pulley. ), It is difficult to accurately match the initial belt tension with the weight load, and it is difficult to evaluate the friction characteristics with high accuracy.
[0008]
An object of the present invention is to evaluate a friction characteristic (friction coefficient or slip load) with high accuracy by evaluating a belt tension at both ends of a belt by attaching a load detector to both ends of the belt.
[0009]
[Means for Solving the Problems]
The friction evaluation device according to claim 1, wherein the rotating body, a belt body, a belt body holding unit that holds the belt body in a state where the belt body is in contact with the rotating body, and a rotation that rotationally drives the rotating body. Body drive means, belt tension load measurement means for measuring the tension load of the belt body, belt tension load measured by the tension load measurement means, and friction characteristic evaluation for calculating an evaluation value of friction characteristic based on an evaluation formula Value calculating means, and has the rotating body driven by the rotating body driving means, measured by the tensile load measuring means, based on the belt tension load generated between the rotating body and the belt body, In the friction evaluation device for calculating a friction evaluation value between the rotating body and the belt body, the belt tension load measuring means includes a belt tension side tension measuring a tension side load of the belt body. A load measuring unit; and a belt slack side tensile load measuring unit that detects a load on the slack side of the belt body. The friction characteristic evaluation value calculating unit includes a belt tension side measured by the belt tension side tensile load measuring unit. An evaluation value of a friction characteristic between the rotating body and the belt body is calculated based on a tensile load, a belt loose side tensile load measured by the belt loose side tensile load measuring unit, and an evaluation formula. And
[0010]
The friction evaluation device according to claim 2 is the friction evaluation device according to claim 1, wherein the frictional characteristic evaluation value calculation means is configured to determine a ratio between the tension load on the belt tension side and the tension load on the belt slack side and the rotating body. A friction coefficient between the rotating body and the belt body is calculated as an evaluation value of the friction characteristic based on a contact angle between the rotating body and the belt body.
[0011]
The friction evaluation device according to claim 3 is the friction evaluation device according to claim 1, wherein the rotating body friction evaluation value calculating means calculates the friction characteristic based on a difference between the belt tension side tension load and the belt slack side load. The slip load generated between the rotating body and the belt body is calculated as the evaluation value of.
[0012]
A friction measuring device according to a fourth aspect of the present invention is the friction evaluation device according to the first aspect, wherein a belt tension side tension load measuring unit that measures a tension side load of the belt body, and measures a loose side load of the belt body. And a belt tension load measuring / moving means capable of moving the belt slack side.
[0013]
According to a fifth aspect of the present invention, there is provided the friction evaluation device according to the fourth aspect, further comprising a belt tension load measurement movement position detecting unit that detects a position of the belt tension load measurement movement unit.
[0014]
The friction evaluation device according to claim 6 is the friction evaluation device according to claim 4, wherein the belt tension side tension load measurement unit and the belt slack side tension load measurement unit are arranged in the axial direction of the rotating body. It is characterized in that it has a measurement section rotation free holding means for holding the rotation freely.
[0015]
According to a seventh aspect of the present invention, there is provided a friction evaluation device according to the first aspect, wherein the belt body holding means includes a belt body rotation free holding means for holding the belt body freely.
[0016]
The friction evaluation device according to claim 8 is the friction evaluation device according to claim 1, wherein a charging member is provided at a position opposite to the rotating member via the belt member, and a charging member is provided between the rotating member and the charging member. And a potential difference generating means for generating a potential difference.
[0017]
The friction evaluation method according to claim 9, further comprising a belt body holding step of holding the belt body in a state where the belt body is in contact with the rotating body, for the rotating body and the belt body, and rotating the rotating body. A rotating body driving step, a belt tensile load measuring step of measuring the tensile load of the belt body, and a belt tensile load measured by the belt tensile load measuring step, and calculating an evaluation value of a friction characteristic based on an evaluation formula. A frictional characteristic evaluation value calculating step, wherein the rotating body is rotationally driven in the rotating body driving step, and a belt tensile load generated between the rotating body and the belt body measured in the belt tensile load measuring step. In the friction evaluation method for calculating a friction evaluation value between the rotating body and the belt body based on the following, the belt tensile load measuring step includes measuring a tension side load of the belt body. A belt tension side tension load measurement step, and a belt slack side tension load measurement step of detecting a loose side load of the belt body, wherein the frictional characteristic evaluation value calculation step is performed by the belt tension side tension load measurement step. Based on the measured belt tension side tensile load, the belt looseness side tensile load measured in the belt loosening side tensile load measuring step, and the evaluation formula, based on the evaluation value, the evaluation value of the frictional property between the rotating body and the belt body. It is characterized in that it is calculated.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing the entire configuration of the friction evaluation device of the embodiment. In FIG. 1, the detailed configurations shown in FIGS. 2 to 6 and the like are omitted.
[0019]
[Specific configuration corresponding to claim 1] (FIGS. 1, 2, and 3)
The friction evaluation device according to the embodiment includes a rotating body 1 and a belt body 2 to be evaluated, a belt body holding unit 3 that holds the belt body 2 in a state where the belt body 2 is in contact with the rotating body 1, A rotating body driving unit 4 for rotating and driving the body 1, a belt tension side tension load measuring unit 5 for measuring a tension side load of the belt body 2 via one belt body holding unit 3, and another belt body holding unit 3, a belt loosening side tension load measuring unit 6 for detecting the loose side load of the belt body 2 via the belt 3, and a tension load measuring and holding unit for holding the belt tight side tensile load measuring unit 5 and the belt loosening side tensile load detecting unit 6. And a rotating body friction evaluation unit 11 for calculating an evaluation value of a friction state between the rotating body 1 and the belt body 2.
[0020]
The belt body holding portion 3 is configured to sandwich the belt body 2 with a rubber member 7, further sandwich a metal plate 8, and then tighten with a bolt 9 and a nut 10 as shown in FIG. 2, for example. The rotator driving unit 4 uses, for example, a motor. The belt tension side tensile load measuring unit 5 and the belt loosening side tensile load measuring unit 6 use, for example, a force gauge. The rotating body friction evaluation unit 11 uses a personal computer having an interface of the tensile load data measured by the belt tension side tensile load measuring unit 5 and the belt loosening side tensile load measuring unit 6, for example.
[0021]
As shown in FIG. 3, the tension load detecting unit holding unit 14 fixes the belt slack side load measuring unit 6 to a slider unit 15 so as to be slidable in the left-right direction in the figure, and attaches the slider unit 15 to a slider base unit 16. It is configured to be fixed to. The belt slack side load measuring unit 6 is configured to be fixed to a threaded bar member 17 and to rotate the nut 18 to move the belt slack side tensile load measuring unit 6. Note that the belt tension side tensile load measuring unit 5 is similarly configured.
[0022]
The belt body holding section 3 corresponds to “belt body holding means”, and the rotating body driving section 4 corresponds to “rotating body driving means”. The belt tension side tension load measuring unit 5 corresponds to “belt tension side tension load detecting means”, and the belt loosening side tension load measuring unit 6 corresponds to “belt loose side tension load detecting means”. The tensile load measuring section 5 and the belt loosening side tensile load measuring section 6 correspond to “belt tensile load measuring means”.
[0023]
The following operation is performed by the above configuration. The belt body holding section 3 holds an end of the belt body 2 so that the belt body 2 contacts the rotating body 1. By rotating the nut 18, both the belt tension side tension load measurement unit 5 and the belt looseness side load measurement unit 6 are moved in the belt tension direction, and an arbitrary belt tension is generated on the belt body 2. Next, the rotator 1 is rotated at an arbitrary speed by the rotator driving unit 4, and the tension-side load (belt-side tension load) of the belt body 2 is measured by the belt-side tension load measurement unit 5. Further, the load on the loose side (belt loose side tensile load) of the belt body 2 is measured by the belt loose side tensile load measuring unit 6. Then, as will be described later, the rotating body friction evaluation unit 11 calculates the friction coefficient from the tension side load, the loose side load, and the evaluation formula.
[0024]
[Specific configuration corresponding to claim 2] (FIG. 1)
Corresponding to claim 2, the rotating body friction evaluating section 11 includes a rotating body friction coefficient calculating section 12 having a function capable of performing a calculation based on the friction coefficient calculating formula of the above equation (5). More specifically, the rotating body friction coefficient calculating unit 12 is configured as a function in which a CPU of a microcomputer executes an arithmetic program.
[0025]
The rotating body friction coefficient calculation unit 12 calculates the tension-side load data measured by the belt tension-side tension load measurement unit 5 and the looseness-side load data measured by the belt looseness-side tension load measurement unit 6. Data of the contact angle manually input in advance is input, and the friction coefficient is calculated based on the theoretical equation of the above equation (5). Then, the rotating body friction evaluation unit 11 operates to output the friction coefficient to, for example, a display (not shown).
[0026]
[Specific configuration corresponding to claim 3]
The rotating body friction evaluator 11 includes a slip load calculator 13 having a function capable of performing a calculation based on the slip load calculation formula of the above equation (1). More specifically, the slip load calculator 13 is configured as a function of causing a CPU of a microcomputer to execute a calculation program.
[0027]
The slip load calculating unit 13 inputs the tension side load data measured by the belt tension side tensile load measuring unit 5 and the loose side load data measured by the belt loosening side tensile load measuring unit 6, The slip load is calculated based on the theoretical equation of the above equation (1). Then, the rotating body friction evaluation unit 11 operates to output the slip load to, for example, a display (not shown).
[0028]
[Specific Configuration Corresponding to Claim 4] (FIGS. 1 and 3)
The friction evaluation device shown in FIG. 1 includes a belt tension side tension load measuring unit 5 for measuring the tension side load of the belt body 2 and a belt slack side tension load measuring unit 6 for measuring the loose side load of the belt body 2. And a belt tension load measuring and moving unit 22 which can move the belt tension load. The belt tension load measuring and moving unit 22 is movable along a guide 23 at an arbitrary height in a direction (vertical direction) orthogonal to the center axis of the rotating body 1. Then, after setting to an arbitrary height, the operation is performed so as to be fixed by a clamp unit (not shown). In addition, the belt tension load measurement moving unit 22 corresponds to “belt tension load measurement movement unit”.
[0029]
[Specific configuration corresponding to claim 5] (FIG. 3)
As shown in FIG. 3, a belt tension load measurement movement position detection unit 19 is arranged in the belt tension load measurement unit movement unit 22. The belt tension load measurement movement position detection unit 19 is, for example, a linear type. Consists of an encoder. Alternatively, a laser length measuring device may be arranged in the belt tension load measuring unit moving unit 22. The belt tension load measurement / movement position detection unit 1-19 or the laser length measuring device (not shown) corresponds to “belt tension load measurement / movement position detection means”.
[0030]
The belt tension load measurement / movement position detection unit 19 operates to detect the position of the belt tension load measurement / movement unit 22 and output the information. For example, as shown in FIG. 4, the distance (known value) from the axis of the rotating body 1 to a vertical line passing through the rotation axis O of the belt tension side tension load measurement unit 5 on the belt tension load measurement movement unit 22 is calculated. L, the radius of the rotating body 1 (known value) is R, and if it is desired to set the contact angle on the belt tension side to α / 2, the rotation of the belt tension side tension load measuring unit 5 from the axial position of the rotating body 1 The contact angle α / 2 is set by calculating the height x to the axis O from the position of the belt tension load measuring and moving unit 22 and substituting these L, R, and x into the following equation (6), and performing the back calculation. can do.
x = (L−Rsin (α / 2)) tan (α / 2) −Rcos (α / 2) (6)
[0031]
[Specific configuration corresponding to claim 6] (FIG. 3)
Using a measuring unit rotation free holding unit 24 that holds the belt tension side tensile load measuring unit 5 and the belt loosening side tensile load measuring unit 6 freely rotatable about an axis parallel to the central axis of the rotating body 1. It is configured. For example, as shown in FIG. 3, a shaft 16 a (the direction of the shaft is perpendicular to the drawing) is provided on the slider base 16, and is held by the bearing 21. Note that the belt tension side tensile load measuring unit 5 is similarly configured. Thereby, when the belt body 2 is mounted, and the belt tension side tension load generated in the belt body 2 when the belt tension side tension load measurement unit 5 and the belt slack side tension load measurement unit 6 are moved, the belt tension side tension load measurement unit 5 and the belt slack side tensile load measuring section 6 operate so that the load detection direction is directed to the belt tensile load direction. During the measurement, when the belt vibrates in the rotation direction due to an imbalance around the belt tension side tensile load measuring unit 5 and the belt loosening side tensile load measuring unit 6, the clamp unit (not shown) causes the measuring unit rotation free holding unit 24 to move. It is desirable to fix.
[0032]
[Specific configuration corresponding to claim 7] (FIG. 5)
The belt body holding unit 3 is configured using a belt body rotation free holding unit 25 that is rotatably fixed to the belt tension side tensile load measuring unit 5 and the belt loosening side tensile load measuring unit 6. For example, as shown in FIG. 5, a mounting bracket 26 is provided at the center of the belt body holding section 3, and the mounting hook 27 attached to the belt tension side tensile load measuring section 5 or the belt loosening side tensile load measuring section 6 is attached to the mounting hook 27. Hook on the mounting bracket 26. Thereby, when the belt body 2 is mounted and the belt tension side tension load measuring unit 5 and the belt slack side tension load measuring unit 6 are moved, the belt body holding is performed by the distribution of the tensile tension generated in the belt body 2. The part 3 operates so as to rotate, and the belt tension distribution becomes uniform.
[0033]
[Specific configuration corresponding to claim 8] (FIG. 6)
As shown in FIG. 6, for example, a charging brush 28 is provided as a charging body at a position opposed to the rotating body 1 via the belt body 2, and the rotating body 1 and the charging brush 28 are connected to the voltage generator 30. Constitute. Then, a voltage is applied by the voltage generator 30 to operate to generate a potential difference between the rotating body 1 and the charging brush 28. Thus, it is possible to evaluate friction at a position where static electricity is generated due to a potential difference.
[0034]
In the case of an electrophotographic process of a copying machine or a printer, transfer of toner developed on a photosensitive drum to a transfer belt by a bias voltage is generally performed. For this reason, in order to evaluate the slip load between the photosensitive drum and the transfer belt, it is necessary to perform measurement with a bias voltage applied. In the method disclosed in JP-A-9-243482, a device for applying a bias voltage can be easily mounted, but a mechanism for moving the device for applying a bias voltage for each contact angle is required. In the item 8), since the contact angle is set by changing the belt fixing positions at both ends of the belt, the slip load and the friction coefficient in a state where the bias voltage is applied can be easily measured.
[0035]
[Evaluation results]
FIG. 7 shows the coefficient of friction between the photosensitive drum and the transfer belt, and FIG. 8 shows the slip load, evaluated using the friction evaluation device of the embodiment. With respect to the friction coefficient, it was possible to quantitatively evaluate that the friction coefficient was reduced when the toner was attached. Further, it is possible to capture a change in the friction coefficient in one rotation cycle of the photosensitive drum due to a change in the interface between the photosensitive drum and the transfer belt. Further, the tendency of the slip load to increase due to the increase in the winding force between the transfer belt and the photosensitive drum due to the electrostatic force due to the potential difference can be grasped.
[0036]
【The invention's effect】
According to the friction evaluation device of the first aspect and the friction evaluation method of the ninth aspect, the tension side tension load and the loose side tension load of the belt body can be measured simultaneously, so that the tension side and the loose side tension when the belt body is mounted. By using the measured values, it is possible to accurately set an arbitrary initial belt tension load, and to evaluate friction characteristics (friction coefficient and slip load) with high accuracy.
[0037]
According to the friction evaluation device of the second aspect, since the ratio between the tension side tensile load and the loose side tension load of the belt body is obtained, an accurate friction coefficient can be evaluated.
[0038]
According to the friction evaluation device of the third aspect, the difference between the tension load on the tension side and the tension load on the loose side of the belt body is obtained, so that an accurate slip load can be evaluated.
[0039]
According to the friction evaluation device of the fourth aspect, since the belt tension load measuring unit can be set at an arbitrary position, an arbitrary contact angle can be set.
[0040]
According to the friction evaluation device of the fifth aspect, since the belt tension load measuring unit can be set accurately at an arbitrary position, an arbitrary contact angle can be set accurately.
[0041]
According to the friction evaluation device of claim 6, when the initial belt tension load of the belt body is set, the belt tension load measuring unit is accurately oriented in the belt tension load direction, so that any contact angle can be accurately determined. Can be set. Further, the belt tensile load can be accurately measured.
[0042]
According to the friction evaluation device of the seventh aspect, since the belt body holding portion relaxes the uneven belt tension distribution due to the belt tension distribution of the belt body, the pressing force against the rotating body due to the tensile load of the belt body. Can be uniformly applied in the axial direction of the rotating body. Further, since the belt body holding portion is supported at one point, the entire belt body tensile load can be accurately measured.
[0043]
According to the friction evaluation device of the eighth aspect, since the friction evaluation device is constituted by the movable belt tension load measuring unit and the charged body, any contact angle can be obtained without moving the charged body and the position at the position where static electricity is generated due to the potential difference. Friction evaluation becomes possible.
[Brief description of the drawings]
FIG. 1 is a diagram showing an overall configuration of a friction evaluation device according to an embodiment of the present invention.
FIG. 2 is a diagram illustrating an example of the belt body holding unit according to the embodiment of the present invention.
FIG. 3 is a diagram illustrating an example of a tensile load detecting unit holding unit, a belt tensile load measuring unit moving unit, and a measuring unit rotation free holding unit according to the embodiment of the present invention.
FIG. 4 is a diagram illustrating a relationship between a contact angle and a position of a load measurement moving unit according to the embodiment of the present invention.
FIG. 5 is a diagram illustrating an example of a belt body rotation free holding unit according to the embodiment of the present invention.
FIG. 6 is a diagram illustrating an example in which a charging member is provided according to an embodiment of the present invention.
FIG. 7 is a diagram illustrating an example of evaluation of a friction coefficient evaluated using the friction evaluation device according to the embodiment of the present invention.
FIG. 8 is a diagram showing an example of evaluating a slip load evaluated using the friction evaluation device according to the embodiment of the present invention.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 rotating body 2 belt body 3 belt body holding section 4 rotating body driving section 5 belt tension side tensile load measuring section 6 belt loosening side tensile load measuring section 11 rotating body friction evaluating section

Claims

A rotating body,
A belt body,
Belt body holding means for holding the belt body in a state where the belt body is in contact with the rotating body,
Rotating body driving means for rotatingly driving the rotating body;
Belt tension load measuring means for measuring the tension load of the belt body,
Belt tensile load measured by the tensile load measuring means, friction characteristic evaluation value calculation means for calculating the evaluation value of the friction characteristic based on the evaluation formula,
Has,
The rotating body is rotationally driven by the rotating body driving means, and the belt tension load generated between the rotating body and the belt body is measured by the tensile load measuring means. In a friction evaluation device that calculates a friction evaluation value,
The belt tension load measurement unit includes a belt tension side tension load measurement unit that measures a tension side load of the belt body, and a belt slack side tension load measurement unit that detects a loose side load of the belt body.
The frictional characteristic evaluation value calculating means, the belt tension side tensile load measured by the belt tension side tensile load measuring means, the belt loose side tensile load measured by the belt loosening side tensile load measuring means, the evaluation formula, A friction evaluation apparatus for calculating an evaluation value of a friction characteristic between the rotating body and the belt body.

The friction evaluation device according to claim 1,
The friction characteristic evaluation value calculation means,
Based on the ratio between the belt tension side tensile load and the belt slack side tensile load, and the contact angle between the rotating body and the belt body, the friction between the rotating body and the belt body is used as an evaluation value of the friction characteristic. A friction evaluation device for calculating a coefficient.

The friction evaluation device according to claim 1,
The rotating body friction evaluation value calculation means,
A friction evaluation device, wherein a slip load generated between the rotating body and the belt body is calculated as an evaluation value of the friction characteristic from a difference between the belt tension side load and the belt slack side load.

The friction evaluation device according to claim 1,
A belt tension load measurement movement that enables movement of a belt tension side tension load measurement unit that measures the tension side load of the belt body, and a belt slack side tension load measurement unit that measures the loose side load of the belt body. A friction measuring device comprising means.

The friction evaluation device according to claim 4,
A friction evaluation device comprising a belt tension load measurement movement position detecting means for detecting a position of the belt tension load measurement movement section.

The friction evaluation device according to claim 4,
A friction unit having a measurement unit rotation free holding unit that holds the belt tension side tension load measurement unit and the belt looseness side tension load measurement unit in a freely rotatable manner with respect to the axial direction of the rotating body. Evaluation device.

The friction evaluation device according to claim 1,
A friction evaluation device, wherein the belt body holding means includes a belt body rotation free holding means for holding the belt body freely.

The friction evaluation device according to claim 1,
A friction evaluation device, comprising: a charging member provided at a position facing the rotating member via the belt member; and a potential difference generating means for generating a potential difference between the rotating member and the charging member.

For the rotating body and the belt body,
A belt body holding step of holding the belt body in a state where the belt body is in contact with the rotating body,
A rotating body driving step of rotatingly driving the rotating body;
A belt tensile load measuring step of measuring the tensile load of the belt body,
Belt tensile load measured by the belt tensile load measuring step, a friction characteristic evaluation value calculation step of calculating an evaluation value of the friction characteristic based on the evaluation formula,
Has,
The rotator is driven to rotate by the rotator driving step, and the belt tension load generated between the rotator and the belt body is measured by the belt tension load measuring step. In the friction evaluation method of calculating the friction evaluation value of
The belt tension load measurement step includes a belt tension side tension load measurement step of measuring a tension side load of the belt body, and a belt slack side tension load measurement step of detecting a loose side load of the belt body.
The frictional characteristic evaluation value calculation step, the belt tension side tensile load measured in the belt tension side tensile load measuring step, the belt loose side tensile load measured in the belt loosening side tensile load measuring step, and the evaluation formula, A friction evaluation method for calculating an evaluation value of a friction characteristic between the rotating body and the belt body.