JP2009122562A

JP2009122562A - Sheet conveying apparatus and image forming apparatus

Info

Publication number: JP2009122562A
Application number: JP2007298819A
Authority: JP
Inventors: Kiyoshi Konuma; 精小沼; Nobuhiko Kita; 信彦喜多; Makoto Izuhara; 良出原; Kazuyoshi Kondo; 和芳近藤; Yusuke Furuichi; 祐介古市; Genta Hagiwara; 元太萩原; Kaoru Tada; 薫多田
Original assignee: Ricoh Co Ltd
Current assignee: Ricoh Co Ltd
Priority date: 2007-11-19
Filing date: 2007-11-19
Publication date: 2009-06-04

Abstract

<P>PROBLEM TO BE SOLVED: To stably press and release a pair of press-contacting members for conveying a sheet between them against each other and from being pressed against each other, and to automatically pressing them against each other at the start of use with inexpensive constitution. <P>SOLUTION: A sheet conveying apparatus includes a press-contacting releasing mechanism and a press-contacting return mechanism. The press-contacting releasing mechanism releases the pair of press-contacting members from being pressed against each other by retracting at least one of the press-contacting members as wedgelike press-contacting release members 43L and 43R provided on a rotary member 40 enters between the pair of press-contacting members 30 and 50 when the rotary member 40 is manually rotated on a pivot 41 to move the press-contacting release members 43L and 43R from standby positions to press-contacting release positions. The press-contacting return mechanism puts the pair of press-contacting members back into a press-contacting state by returning the press-contacting release members from the press-contact release positions to the standby positions by transmitting the driving force of a driving source such as a motor to the rotary member 40 through a return gear train D2 while rotating the press-contacting members by transmitting the driving force of the driving source at the start of use. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

この発明は、複写機、プリンタ、ファクシミリまたはそれらの複合機など、像担持体上に形成したトナー像が、直接転写され、または中間転写体を介して間接的に転写された後、定着を行うことにより、用紙、樹脂フィルム等のシートに画像が記録される画像形成装置に関する。および、そのような画像形成装置において、シートを搬送するシート搬送装置、例えばシートを搬送しながら、熱と圧力とが加えられて、転写後の未定着トナー像がシートに定着される定着装置などに関する。 The present invention performs fixing after a toner image formed on an image carrier such as a copying machine, a printer, a facsimile, or a composite machine thereof is directly transferred or indirectly transferred via an intermediate transfer member. The present invention relates to an image forming apparatus in which an image is recorded on a sheet such as paper or a resin film. In such an image forming apparatus, a sheet conveying apparatus that conveys the sheet, for example, a fixing apparatus that fixes an unfixed toner image after transfer to the sheet by applying heat and pressure while conveying the sheet. About.

電子写真式画像形成装置の定着装置にあっては、加熱部材とそれに押し当てる加圧部材とで定着ニップが形成され、その定着ニップにシートを通して熱と圧力とが加えられ、転写後の未定着トナー像がシートに定着されるタイプのものが、比較的簡易な構成でほぼ満足できる定着効果が得られることから、現在多く使用されている。 In a fixing device of an electrophotographic image forming apparatus, a fixing nip is formed by a heating member and a pressure member pressed against the heating member, heat and pressure are applied to the fixing nip through a sheet, and unfixed after transfer A type in which a toner image is fixed on a sheet is widely used because a satisfactory fixing effect can be obtained with a relatively simple configuration.

ところで、このような定着装置では、今日、電子写真式画像形成装置における生産性の向上（処理速度の高速化）、カラー化、メディアの多様化の要請などから、それらの要請に応えるべく、加熱部材に対する加圧部材の圧接力が増加傾向にある。 By the way, in such a fixing device, in order to meet these demands from today's demands for improvement in productivity (higher processing speed), colorization, and diversification of media in an electrophotographic image forming apparatus. The pressure contact force of the pressure member to the member tends to increase.

しかしながら、圧接力の増大は、長期間の未使用時において加熱部材や加圧部材の変形や変質を招き、シート搬送性を低下したり定着性を悪化したりするおそれがあった。また、シート搬送ジャム時に、シートを取り除くとき、シートを破損するなど、ジャム処理時の作業性を悪くしていた。 However, an increase in the pressure contact force may cause deformation or alteration of the heating member or the pressure member when not in use for a long period of time, and there is a possibility that the sheet conveyance property is deteriorated or the fixing property is deteriorated. Further, when removing the sheet during the sheet conveyance jam, the workability at the time of the jam processing is deteriorated such that the sheet is damaged.

従来の画像形成装置の中には、このような不具合を解消すべく、例えば特許文献１に記載される図７に示す定着装置のように、加熱ローラ１と、加圧ローラ２と、それを加熱ローラ１に押し当てて定着ニップを形成する付勢部材３と、加熱ローラ１と加圧ローラ２との間に入り込んで付勢部材２に抗して加圧ローラ３を退避してそれらのローラ１、２を離間する楔形状の圧接解除部材４と、その圧接解除部材４を駆動するソレノイド等の駆動源５とが備えられているものがある。 In a conventional image forming apparatus, in order to solve such a problem, for example, as in the fixing device shown in FIG. An urging member 3 that presses against the heating roller 1 to form a fixing nip, and enters between the heating roller 1 and the pressure roller 2 to retreat the pressure roller 3 against the urging member 2 and move them. Some of them include a wedge-shaped pressure release member 4 that separates the rollers 1 and 2 and a drive source 5 such as a solenoid that drives the pressure release member 4.

特開２００４−２６４７０６号公報JP 2004-264706 A

ところが、特許文献１には、駆動源をどのように設けてどのように駆動するかについては、詳しく記載されておらず、加熱ローラ１と加圧ローラ２との圧接と圧接解除とを安定的に行う構成が開示されていなかった。また、圧接と圧接解除専用の駆動源５を別途備えるものであり、コスト高となる問題もあった。 However, Patent Document 1 does not describe in detail how the drive source is provided and how it is driven, and the pressure contact between the heating roller 1 and the pressure roller 2 and the pressure contact release are stable. The configuration to be performed was not disclosed. In addition, a separate drive source 5 dedicated to the pressure contact and pressure release is provided, and there is a problem that the cost increases.

そこで、この発明の目的は、シートを挟んで搬送する一対の圧接部材の圧接と圧接解除とを安定的に行うことができるとともに、安価な構成で使用開始時には自動的に圧接することができるようにすることにある。 SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to stably perform pressure contact and pressure release of a pair of pressure contact members conveyed with a sheet interposed therebetween, and to automatically perform pressure contact at the start of use with an inexpensive configuration. Is to make it.

この発明の第２の目的は、圧接解除部材が待機位置に戻ったとき、駆動源からの駆動伝達を遮断して圧接解除部材を待機位置に保持することにある。 The second object of the present invention is to hold the pressure release member at the standby position by interrupting the drive transmission from the drive source when the pressure release member returns to the standby position.

この発明の第３の目的は、圧接解除部材を待機位置に安定的に保持することにある。 The third object of the present invention is to stably hold the pressure release member at the standby position.

この発明の第４の目的は、圧接解除部材を待機位置にふらつくことなく安定的に位置決め保持することにある。 A fourth object of the present invention is to stably position and hold the pressure release member without swinging to the standby position.

この発明の第５の目的は、圧接解除時の手動操作を軽くし、作業性を向上することにある。 A fifth object of the present invention is to lighten manual operation when releasing pressure contact and improve workability.

この発明の第６の目的は、シートを挟んで搬送する加熱部材と加圧部材の圧接と圧接解除とを安定的に行うことができるとともに、安価な構成で使用開始時には自動的に圧接することができるようにすることにある。 A sixth object of the present invention is to stably perform pressure contact and pressure contact release between a heating member and a pressure member which are conveyed while sandwiching a sheet, and to automatically perform pressure contact at the start of use with an inexpensive configuration. Is to be able to.

この発明の第７の目的は、シートを挟んで搬送する一対の圧接部材の圧接と圧接解除とを安定的に行うことができるとともに、安価な構成で使用開始時には自動的に圧接することができるシート搬送装置が備えられている画像形成装置を提供することにある。 A seventh object of the present invention is to stably perform pressure contact and pressure release of a pair of pressure contact members that are conveyed with a sheet sandwiched therebetween, and can automatically perform pressure contact at the start of use with an inexpensive configuration. An object of the present invention is to provide an image forming apparatus provided with a sheet conveying device.

この発明の第８の目的は、画像形成装置において、シート搬送装置の一対の圧接部材の圧接と圧接解除の作動安定性を確保しつつ、駆動伝達系の負荷をなくして圧接解除時の手動操作を軽くし、作業性を向上することにある。 An eighth object of the present invention is to provide a manual operation at the time of releasing the pressure contact by eliminating the load of the drive transmission system while ensuring the operational stability of the pressure contact and pressure release of the pair of pressure contact members of the sheet conveying device in the image forming apparatus. Is to improve workability.

この発明の第９の目的は、画像形成装置において、ジャム処理時の作業性を向上することにある。 A ninth object of the present invention is to improve workability at the time of jam processing in an image forming apparatus.

このため、請求項１に記載の発明は、上述した第１の目的を達成すべく、
互いに圧接する一対の圧接部材間の定着ニップ等の圧接ニップに、用紙、樹脂フィルム等のシートを挿入して少なくとも一方の圧接部材を回転することによりシートを搬送するシート搬送装置において、
使用終了後に、手動操作して支軸を中心として回動部材を回動し、その回動部材に設ける楔形状等の圧接解除部材を待機位置から圧接解除位置に移動したとき、その圧接解除部材が一対の圧接部材間に入り込むなどによって、少なくとも一方の圧接部材を退避して前記一対の圧接部材の圧接を解除する圧接解除機構と、
使用開始時、駆動モータ等の駆動源の駆動力を伝達して前記圧接部材を回転するとき、同時に復帰ギヤ列を介して前記駆動源の駆動力を前記回動部材に伝達して前記圧接解除部材を前記圧接解除位置から前記待機位置に戻し、前記一対の圧接部材を圧接状態に復帰する圧接復帰機構と、
が備えられていることを特徴とする。 For this reason, the invention described in claim 1 is to achieve the first object described above.
In a sheet conveying apparatus that conveys a sheet by inserting a sheet such as a sheet of paper or a resin film into a pressure nip such as a fixing nip between a pair of pressure members that are in pressure contact with each other and rotating at least one pressure member.
After completion of use, when the rotation member is rotated manually around the support shaft and the wedge-shaped pressure release member provided on the rotation member is moved from the standby position to the pressure release position, the pressure release member A pressure release mechanism that retracts at least one pressure contact member and releases the pressure contact of the pair of pressure contact members, for example, by entering between a pair of pressure contact members,
At the start of use, when the pressure contact member is rotated by transmitting a drive force of a drive source such as a drive motor, the drive force of the drive source is simultaneously transmitted to the rotating member via a return gear train to release the pressure contact. A pressure return mechanism for returning a member from the pressure release position to the standby position and returning the pair of pressure contact members to a pressure contact state;
Is provided.

使用開始時には、駆動源の駆動力を伝達して圧接部材を回転するとき、同時に復帰ギヤ列を介して駆動源の駆動力を回動部材に伝達して圧接解除部材を圧接解除位置から待機位置に戻し、圧接復帰機構で一対の圧接部材が圧接状態に復帰される。そして、互いに圧接する一対の圧接部材間の圧接ニップにシートを挿入し、駆動源の駆動力を伝達して少なくとも一方の圧接部材を回転することによりシートが搬送される。 At the start of use, the driving force of the driving source is transmitted to rotate the pressure contact member, and at the same time, the driving force of the driving source is transmitted to the rotating member via the return gear train so that the pressure releasing member is moved from the pressure releasing position to the standby position. The pair of pressure contact members are returned to the pressure contact state by the pressure contact return mechanism. Then, the sheet is conveyed by inserting a sheet into a pressure nip between a pair of pressure members that are in pressure contact with each other, transmitting a driving force of a driving source and rotating at least one pressure member.

使用終了後は、手動操作して支軸を中心として回動部材を回動し、その回動部材に設ける楔形状等の圧接解除部材を待機位置から圧接解除位置に移動したとき、その圧接解除部材が一対の圧接部材間に入り込むなどによって、圧接解除機構で少なくとも一方の圧接部材を退避して一対の圧接部材の圧接が解除される。 After use, manually rotate the pivot member around the support shaft, and when the wedge-shaped pressure release member provided on the pivot member is moved from the standby position to the pressure release position, the pressure release is released. When the member enters between the pair of pressure contact members, the pressure contact release mechanism retracts at least one of the pressure contact members to release the pressure contact between the pair of pressure contact members.

請求項２に記載の発明は、上述した第２の目的を達成すべく、請求項１に記載のシート搬送装置において、前記復帰ギヤ列に、欠歯ギヤと、それにかみ合って前記駆動源からの駆動力を伝達するアイドラギヤとが設けられており、前記欠歯ギヤには、前記圧接解除部材が前記待機位置に戻ったとき、前記アイドラギヤとのかみ合いを解除する欠歯部が形成されていることを特徴とする。 According to a second aspect of the present invention, in order to achieve the second object described above, in the sheet conveying apparatus according to the first aspect, the return gear train is provided with a missing gear and meshed with the drive gear from the drive source. An idler gear for transmitting a driving force is provided, and the missing tooth portion is formed with a missing tooth portion for releasing the engagement with the idler gear when the pressure release member returns to the standby position. It is characterized by.

そして、使用開始時には、駆動源の駆動力をアイドラギヤと欠歯ギヤとのかみ合いを介して回動部材に伝達して圧接解除部材を待機位置に戻し、圧接復帰機構で一対の圧接部材が圧接状態に復帰される。この圧接解除部材が待機位置に戻った状態では、アイドラギヤには、欠歯ギヤの欠歯部が対向して欠歯ギヤとアイドラギヤとのかみ合いが解除される。使用終了後に、手動操作により回動部材が回動されると、欠歯ギヤが回転されてアイドラギヤと噛み合う。 At the start of use, the driving force of the drive source is transmitted to the rotating member via the meshing between the idler gear and the toothless gear to return the pressure contact release member to the standby position, and the pressure contact return mechanism causes the pair of pressure contact members to be in a pressure contact state. Returned to In a state where the pressure release member is returned to the standby position, the idler gear is opposed to the missing tooth portion of the missing gear, and the engagement between the missing gear and the idler gear is released. When the turning member is turned manually after the use is finished, the missing gear is rotated and meshed with the idler gear.

請求項３に記載の発明は、上述した第３の目的を達成すべく、請求項１または２に記載のシート搬送装置において、前記回動部材を付勢して前記圧接解除部材を前記待機位置に保持する付勢部材が設けられていることを特徴とする。そして、付勢部材で回動部材を付勢して圧接解除部材が待機位置へと向けられる。 According to a third aspect of the present invention, in order to achieve the third object described above, in the sheet conveying apparatus according to the first or second aspect, the rotating member is urged so that the pressure release member is moved to the standby position. An urging member is provided for holding the urging member. Then, the rotation member is urged by the urging member, and the pressure release member is directed to the standby position.

請求項４に記載の発明は、上述した第４の目的を達成すべく、請求項３に記載のシート搬送装置において、前記付勢部材の付勢力で前記回動部材を押し当てて前記圧接解除部材を前記待機位置に位置決めする押当位置決め部が設けられていることを特徴とする。そして、付勢部材で回動部材を付勢して圧接解除部材が押当位置決め部に押し当てられ、位置決めして待機位置に保持される。 According to a fourth aspect of the present invention, in order to achieve the fourth object described above, in the sheet conveying apparatus according to the third aspect, the rotating member is pressed by the urging force of the urging member to release the pressure contact. A pressing positioning portion for positioning the member at the standby position is provided. Then, the rotation member is urged by the urging member, the pressure release member is pressed against the pressing positioning portion, and is positioned and held at the standby position.

請求項５に記載の発明は、上述した第５の目的を達成すべく、請求項１ないし４のいずれか１に記載のシート搬送装置において、前記駆動源の駆動力を伝達して前記圧接部材を回転する駆動伝達系に対して、前記復帰ギヤ列を切り離すクラッチ機構が設けられていることを特徴とする。 According to a fifth aspect of the present invention, in order to achieve the fifth object described above, in the sheet conveying apparatus according to any one of the first to fourth aspects, the driving force of the driving source is transmitted to the press contact member. A clutch mechanism for separating the return gear train is provided for the drive transmission system that rotates the motor.

そして、使用終了後、クラッチ機構を切断して駆動伝達系に対して復帰ギヤ列を切り離してから、手動操作して支軸を中心として回動部材を回動し、圧接解除部材を圧接解除位置に移動して、その圧接解除部材で少なくとも一方の圧接部材を退避して一対の圧接部材の圧接が解除される。 After the use is completed, the clutch mechanism is disconnected to disconnect the return gear train from the drive transmission system, and then the manual operation is performed to rotate the rotating member around the support shaft. The pressure contact release member retracts at least one of the pressure contact members, and the pressure contact between the pair of pressure contact members is released.

請求項６に記載の発明は、上述した第６の目的を達成すべく、請求項１ないし５のいずれか１に記載のシート搬送装置において、前記一対の圧接部材として、シートを加熱する加熱部材と、それに押し当てて定着ニップを形成する加圧部材とが備えられている定着装置であることを特徴とする。 According to a sixth aspect of the present invention, in order to achieve the sixth object described above, in the sheet conveying apparatus according to any one of the first to fifth aspects, a heating member that heats a sheet as the pair of press contact members And a pressure member that is pressed against the pressure member to form a fixing nip.

使用開始時には、駆動源の駆動力を伝達して加熱部材を回転するとき、同時に復帰ギヤ列を介して駆動源の駆動力を回動部材に伝達して圧接解除部材を圧接解除位置から待機位置に戻し、圧接復帰機構で加熱部材と加圧部材が圧接状態に復帰される。そして、互いに圧接する加熱部材と加圧部材間の定着ニップにシートを挿入し、駆動源の駆動力を伝達して加熱部材を回転することによりシートが搬送される。 At the start of use, when the heating member is rotated by transmitting the driving force of the driving source, the driving force of the driving source is simultaneously transmitted to the rotating member via the return gear train, and the pressure release member is moved from the pressure release position to the standby position. The heating member and the pressure member are returned to the pressure contact state by the pressure contact return mechanism. Then, the sheet is conveyed by inserting the sheet into the fixing nip between the heating member and the pressure member that are in pressure contact with each other, transmitting the driving force of the driving source and rotating the heating member.

使用終了後は、手動操作して支軸を中心として回動部材を回動し、その回動部材に設ける楔形状等の圧接解除部材を待機位置から圧接解除位置に移動したとき、その圧接解除部材が加熱部材と加圧部材間に入り込むなどによって、圧接解除機構で加圧部材を退避して加熱部材と加圧部材の圧接が解除される。 After use, manually rotate the pivot member around the support shaft, and when the wedge-shaped pressure release member provided on the pivot member is moved from the standby position to the pressure release position, the pressure release is released. When the member enters between the heating member and the pressure member, the pressure member is retracted by the pressure release mechanism, and the pressure contact between the heating member and the pressure member is released.

請求項７に記載の発明は、上述した第７の目的を達成すべく、複写機、プリンタ、ファクシミリまたはそれらの複合機などの画像形成装置において、請求項１ないし６のいずれか１に記載のシート搬送装置が備えられていることを特徴とする。 According to a seventh aspect of the present invention, there is provided an image forming apparatus such as a copying machine, a printer, a facsimile, or a complex machine thereof in order to achieve the seventh object. A sheet conveying device is provided.

請求項８に記載の発明は、上述した第８の目的を達成すべく、請求項７に記載の画像形成装置において、前記駆動源の駆動力を伝達して前記圧接部材を回転する駆動伝達系に対して、前記復帰ギヤ列を切り離すクラッチ機構が設けられており、そのクラッチ機構を、前記駆動源の駆動を開始する所定時間前に接続し、前記駆動源の駆動を停止した所定時間後に切断するように制御するクラッチ制御手段が備えられていることを特徴とする。 According to an eighth aspect of the present invention, in order to achieve the eighth object described above, in the image forming apparatus according to the seventh aspect, a driving transmission system for transmitting the driving force of the driving source to rotate the pressure contact member. On the other hand, a clutch mechanism for separating the return gear train is provided, and the clutch mechanism is connected to a predetermined time before starting to drive the drive source and disconnected after a predetermined time when driving of the drive source is stopped. A clutch control means is provided for performing control.

請求項９に記載の発明は、上述した第９の目的を達成すべく、請求項７または８に記載の画像形成装置において、前記駆動源の駆動力を伝達して前記圧接部材を回転する駆動伝達系に対して、前記復帰ギヤ列を切り離すクラッチ機構が設けられており、そのクラッチ機構を、画像形成装置本体の外装カバーを開いたとき切断するように制御するクラッチ制御手段が備えられていることを特徴とする。 According to a ninth aspect of the present invention, in order to achieve the ninth object described above, in the image forming apparatus according to the seventh or eighth aspect, the driving force of the driving source is transmitted to rotate the pressure contact member. A clutch mechanism for separating the return gear train is provided for the transmission system, and clutch control means for controlling the clutch mechanism to be disconnected when the exterior cover of the image forming apparatus main body is opened is provided. It is characterized by that.

請求項１に記載の発明によれば、使用終了後は、手動操作して支軸を中心として回動部材を回動し、圧接解除機構で少なくとも一方の圧接部材を退避して一対の圧接部材の圧接を解除する一方、使用開始時には、駆動源の駆動力を伝達して圧接部材を回転するとき、同時に復帰ギヤ列を介して駆動源の駆動力を回動部材に伝達して圧接解除部材を圧接解除位置から待機位置に戻し、圧接復帰機構で一対の圧接部材を圧接状態に復帰するので、シートを挟んで搬送する一対の圧接部材の圧接と圧接解除の作動安定性を確保し、長期間の未使用に的確に対応することができる。 According to the first aspect of the present invention, after the use is finished, the rotary member is rotated around the support shaft by manual operation, and at least one of the press contact members is retracted by the press release mechanism, and the pair of press contact members On the other hand, at the start of use, the driving force of the driving source is transmitted to rotate the pressing member, and at the same time, the driving force of the driving source is transmitted to the rotating member via the return gear train. Is returned to the standby position from the pressure release position, and the pair of pressure contact members are returned to the pressure contact state by the pressure return mechanism, so that the operation stability of the pressure contact and pressure release of the pair of pressure contact members transported across the sheet is ensured and long. It is possible to accurately cope with unused periods.

また、圧接部材を回転する駆動源を用いて圧接解除部材を待機位置に戻すので、圧接解除専用の駆動源を必要とすることなく、安価な構成で使用開始時には自動的に圧接することができる。使用開始時には、別途操作を行う必要なく自動的に圧接するので、煩わしくなく、解除忘れによるシート搬送ジャムや定着不良などの発生を防止することができる。 Further, since the pressure release member is returned to the standby position by using a drive source that rotates the pressure contact member, it is possible to automatically press contact at the start of use with an inexpensive configuration without requiring a drive source dedicated to pressure contact release. . At the start of use, the pressure contact is automatically performed without the need for separate operation, so there is no inconvenience, and it is possible to prevent the occurrence of sheet conveyance jamming or fixing failure due to forgetting to release.

請求項２に記載の発明によれば、圧接解除部材が待機位置に戻ったとき、アイドラギヤには、欠歯ギヤの欠歯部が対向して欠歯ギヤとアイドラギヤとのかみ合いが解除されるので、欠歯ギヤとアイドラギヤとの間で駆動源からの駆動伝達を遮断して、圧接解除部材を待機位置に保持することができる。 According to the second aspect of the present invention, when the pressure release member returns to the standby position, the idler gear is opposed to the missing tooth portion of the missing gear so that the engagement between the missing tooth gear and the idler gear is released. The drive transmission from the drive source can be cut off between the toothless gear and the idler gear, and the pressure release member can be held at the standby position.

請求項３に記載の発明によれば、付勢部材で回動部材を付勢して圧接解除部材を待機位置に保持するので、圧接解除部材を待機位置にふらつくことなく安定的に保持することができる。 According to the third aspect of the invention, the rotating member is urged by the urging member to hold the pressure contact release member at the standby position, so that the pressure release member can be stably held without wobbling at the standby position. Can do.

請求項４に記載の発明によれば、付勢部材で回動部材を付勢して圧接解除部材を押当位置決め部に押し当て、位置決めして待機位置に保持するので、圧接解除部材を待機位置にふらつくことなく安定的に適宜位置に位置決め保持することができる。 According to the fourth aspect of the invention, the rotating member is urged by the urging member so that the pressure contact releasing member is pressed against the pressing positioning portion and is positioned and held at the standby position. Positioning and holding can be performed at an appropriate position stably without fluctuation.

請求項５に記載の発明によれば、使用終了後、クラッチ機構を切断して駆動伝達系に対して復帰ギヤ列を切り離してから、手動操作して支軸を中心として回動部材を回動し、圧接解除部材を圧接解除位置に移動して、その圧接解除部材で少なくとも一方の圧接部材を退避して一対の圧接部材の圧接が解除されるので、駆動伝達系の負荷をなくして圧接解除時の手動操作を軽くし、作業性を向上することができる。 According to the fifth aspect of the present invention, after the use is completed, the clutch mechanism is disconnected to disconnect the return gear train from the drive transmission system, and then the manual operation is performed to rotate the rotating member around the support shaft. Then, the pressure release member is moved to the pressure release position, and at least one of the pressure contact members is retracted by the pressure release member so that the pressure contact between the pair of pressure contact members is released. Manual operation at the time can be lightened and workability can be improved.

請求項６に記載の発明によれば、使用終了後は、手動操作して支軸を中心として回動部材を回動し、圧接解除機構で加圧部材を退避して加熱部材と加圧部材の圧接を解除する一方、使用開始時には、駆動源の駆動力を伝達して加熱部材を回転するとき、同時に復帰ギヤ列を介して駆動源の駆動力を回動部材に伝達して圧接解除部材を圧接解除位置から待機位置に戻し、圧接復帰機構で加熱部材と加圧部材を圧接状態に復帰するので、シートを挟んで搬送する加熱部材と加圧部材の圧接と圧接解除とを安定的に行うことができる。 According to the sixth aspect of the present invention, after the use is completed, the rotating member is rotated around the support shaft by manual operation, and the pressing member is retracted by the press release mechanism to heat the heating member and the pressing member. On the other hand, at the start of use, when the heating member is rotated by transmitting the driving force of the driving source, the driving force of the driving source is simultaneously transmitted to the rotating member via the return gear train. Since the heating member and the pressure member are returned to the pressure contact state by the pressure contact return mechanism from the pressure release position, the pressure contact and pressure contact between the heating member and the pressure member conveyed with the sheet sandwiched therebetween can be stably performed. It can be carried out.

また、加熱部材を回転する駆動源を用いて圧接解除部材を待機位置に戻すので、圧接解除専用の駆動源を必要とすることなく、安価な構成で使用開始時には自動的に圧接することができる。使用開始時には、自動的に圧接するので、煩わしくなく、解除忘れによるシート搬送ジャムや定着不良などの発生を防止することができる。 In addition, since the pressure release member is returned to the standby position by using a drive source that rotates the heating member, it is possible to automatically make pressure contact at the start of use with an inexpensive configuration without requiring a drive source dedicated to pressure release. . At the start of use, the pressure contact is automatically made, so there is no trouble, and it is possible to prevent occurrence of sheet conveyance jam or fixing failure due to forgetting to release.

請求項７に記載の発明によれば、画像形成装置において、請求項１ないし６のいずれか１に記載のシート搬送装置が備えられているので、上記効果を有するシート搬送装置が備えられている画像形成装置を提供することができる。 According to the seventh aspect of the present invention, since the image forming apparatus includes the sheet conveying device according to any one of the first to sixth aspects, the sheet conveying device having the above effect is provided. An image forming apparatus can be provided.

請求項８に記載の発明によれば、駆動源の駆動力を伝達して圧接部材を回転する駆動伝達系に対して、復帰ギヤ列を切り離すクラッチ機構を、駆動源の駆動を開始する所定時間前に接続し、駆動源の駆動を停止した所定時間後に切断するように制御するクラッチ制御手段が備えられているので、画像形成装置において、シート搬送装置の一対の圧接部材の圧接と圧接解除の作動安定性を確保しつつ、駆動伝達系の負荷をなくして圧接解除時の手動操作を軽くし、作業性を向上することができる。 According to the eighth aspect of the present invention, the clutch mechanism that separates the return gear train from the driving transmission system that transmits the driving force of the driving source and rotates the pressure contact member, the predetermined time for starting the driving of the driving source. Since the clutch control means is provided to control the disconnection after a predetermined time after the drive source is stopped and the drive source is stopped, in the image forming apparatus, the pressure contact of the pair of pressure contact members of the sheet conveying device and the pressure contact release While ensuring the operational stability, it is possible to eliminate the load on the drive transmission system, lighten the manual operation when releasing the pressure contact, and improve workability.

請求項９に記載の発明によれば、駆動源の駆動力を伝達して圧接部材を回転する駆動伝達系に対して、復帰ギヤ列を介して圧接解除部材を戻す復帰ギヤ列を切り離すクラッチ機構を、画像形成装置本体の外装カバーを開いたとき切断するように制御するクラッチ制御手段が備えられているので、シート搬送ジャム時に外装カバーを開いたとき、別途クラッチ機構を切断することなく、一対の圧接部材の圧接を解除することができ、ジャム処理時の作業性を向上することができる。 According to the ninth aspect of the present invention, the clutch mechanism for separating the return gear train that returns the pressure contact release member via the return gear train to the drive transmission system that transmits the driving force of the drive source and rotates the pressure contact member. Is provided with a clutch control means for controlling the image forming apparatus main body so as to be disconnected when the exterior cover is opened. The pressure contact of the pressure contact member can be released, and the workability at the time of jam processing can be improved.

以下、図面を参照しつつ、この発明の実施の最良形態につき説明する。
図１には、この発明によりシート搬送装置が備えられている画像形成装置の全体概略構成を示す。 The best mode for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 shows an overall schematic configuration of an image forming apparatus provided with a sheet conveying apparatus according to the present invention.

図示画像形成装置には、画像形成装置本体１０の底部に、シートである用紙１１を積載して収容した給紙カセット１２が着脱自在に備えられている。給紙カセット１２の前方には、用紙束に上から接触し、用紙１１を一枚ずつ分離して上から順に繰り出す給紙ローラ１３が設けられている。そして、その給紙位置から画像形成装置本体１０上の排紙積載面１４に向けて下から上へと、図中鎖線で示す用紙搬送経路１５が形成されている。 The illustrated image forming apparatus is detachably equipped with a paper feed cassette 12 in which sheets 11 as sheets are stacked and accommodated on the bottom of the image forming apparatus main body 10. In front of the paper feed cassette 12, there is provided a paper feed roller 13 that contacts the paper bundle from above, separates the paper 11 one by one, and feeds the paper 11 in order from the top. A sheet conveyance path 15 indicated by a chain line in the drawing is formed from the sheet feeding position toward the sheet discharge stacking surface 14 on the image forming apparatus main body 10 from the bottom to the top.

用紙搬送経路１５には、はじまりの給紙ローラ１３から順に、レジストローラ対１６、像担持体１７に転写ローラ１８を押し当てて形成される転写ニップＴ、この発明によるシート搬送装置である詳しくは後述する定着装置２０、排紙ローラ対２１が順に設けられている。 The sheet conveying path 15 includes a registration roller pair 16 and a transfer nip T formed by pressing the transfer roller 18 against the image carrier 17 in order from the paper feeding roller 13 at the beginning, and the sheet conveying apparatus according to the present invention. A fixing device 20 and a discharge roller pair 21 to be described later are provided in this order.

像担持体１７は、この例ではドラム状に形成されており、まわりには不図示の帯電手段、光書込み手段２２、現像手段２３、上述の転写ローラ１８、不図示のクリーニング手段や除電手段などが配置されている。 In this example, the image carrier 17 is formed in a drum shape, and includes a charging unit (not shown), an optical writing unit 22, a developing unit 23, the transfer roller 18 described above, a cleaning unit and a discharging unit (not shown), and the like. Is arranged.

そして、像担持体１７の反時計まわりの回転とともに、不図示の帯電手段で像担持体１７の表面が一様に帯電され、次いで光書込み手段２２で書き込みが行われて像担持体１７上に静電潜像が形成され、そののち現像手段２３でトナーが付着されてその静電潜像が現像され、像担持体１７上にトナー像が形成される。 Then, as the image carrier 17 rotates counterclockwise, the surface of the image carrier 17 is uniformly charged by a charging unit (not shown), and then writing is performed by the optical writing unit 22 so as to be placed on the image carrier 17. An electrostatic latent image is formed, and then the toner is attached by the developing means 23 to develop the electrostatic latent image, and a toner image is formed on the image carrier 17.

他方、給紙ローラ１２の反時計まわりの回転により繰り出された用紙１１は、レジストローラ対１６に突き当てられ、上述した像担持体１７上のトナー像にタイミングを合わせてそのレジストルーラ対１６の回転を開始して転写ニップＴに送り込まれる。そして、その用紙１１に、転写ローラ１８により像担持体１７上のトナー像が転写される。 On the other hand, the paper 11 fed out by the counterclockwise rotation of the paper feed roller 12 is abutted against the registration roller pair 16, and the registration ruler pair 16 of the registration ruler pair 16 is synchronized with the toner image on the image carrier 17 described above. The rotation is started and fed into the transfer nip T. Then, the toner image on the image carrier 17 is transferred to the paper 11 by the transfer roller 18.

トナー像転写後の用紙１１は、定着装置２０に送り込まれ、そこで熱と圧力とを加えてトナー像を定着して後、排紙ローラ対２１により排出されて排紙積載面１４上に積載される。なお、トナー像転写後の像担持体１７の表面は、不図示のクリーニング装置でクリーニング後、除電装置で除電して初期化し、再度の画像形成に備えられる。 The sheet 11 after transfer of the toner image is sent to the fixing device 20 where heat and pressure are applied to fix the toner image, and then the sheet 11 is discharged by the discharge roller pair 21 and stacked on the discharge stacking surface 14. The The surface of the image carrier 17 after the transfer of the toner image is cleaned by a cleaning device (not shown), is neutralized by a static eliminator, is initialized, and is prepared for another image formation.

図２には、図１にこの発明によるシート搬送装置の一例として示す定着装置２０の概略構成を示す。
図２に示すように、図示例の定着装置２０は、位置固定の第１フレーム２５と、それに対して近接・離間可能な第２フレーム２６とで構成されており、それらの間には、上述した用紙搬送経路１５が形成されている。 FIG. 2 shows a schematic configuration of a fixing device 20 shown in FIG. 1 as an example of the sheet conveying device according to the present invention.
As shown in FIG. 2, the fixing device 20 in the illustrated example includes a first frame 25 that is fixed in position and a second frame 26 that can be moved toward and away from the first frame 25. The sheet transport path 15 is formed.

第１フレーム２５では、互いに圧接する一対の圧接部材の一方である加熱ローラ３０がローラ軸３２を中心として回転自在に保持されている。図１に示すように、この例では、用紙１１を加熱する加熱ローラ３０に、発熱体３１が内蔵されている。一方の圧接部材は、ローラに限らず、複数のローラに掛けまわす無端ベルトであってもよく、発熱体は、圧接部材に内蔵される場合に限らず、外部に設けられるものであってもよい。また、圧接部材は、電磁誘導方式により発熱されるものであってもよい。 In the first frame 25, the heating roller 30, which is one of a pair of pressure contact members that are in pressure contact with each other, is held rotatably about the roller shaft 32. As shown in FIG. 1, in this example, a heating element 31 is built in a heating roller 30 that heats the paper 11. One pressure contact member is not limited to a roller, but may be an endless belt that is wound around a plurality of rollers, and the heating element is not limited to being built in the pressure contact member, and may be provided outside. . Further, the pressure contact member may generate heat by an electromagnetic induction method.

加熱ローラ３０のローラ軸３２には、ローラ部の軸方向左右両側に軸間リング３３Ｌ、３３Ｒが設けられている。また、ローラ軸３２上には、一方の軸間リング３３Ｌの外側に駆動伝達系Ｄ１の入力ギヤ３４が固定されており、さらにその外側に電磁クラッチ３５を介して復帰ギヤ列Ｄ２の伝達ギヤ３６が固定されている。 The roller shaft 32 of the heating roller 30 is provided with inter-shaft rings 33L and 33R on the left and right sides in the axial direction of the roller portion. On the roller shaft 32, an input gear 34 of the drive transmission system D1 is fixed to the outside of the one inter-shaft ring 33L, and further to the outside thereof, the transmission gear 36 of the return gear train D2 is connected via an electromagnetic clutch 35. Is fixed.

図３には、その加熱ローラ３０の一端部を拡大して示す。
図示するように加熱ローラ３０のローラ軸３２上には、駆動伝達系Ｄ１の入力ギヤ３４と復帰ギヤ列Ｄ２の伝達ギヤ３６とが、クラッチ機構の一例として示す電磁クラッチ３５を介して設けられている。そして、電磁クラッチ３５には、クラッチ制御手段３７が接続されている。 FIG. 3 shows an enlarged end portion of the heating roller 30.
As shown in the figure, on the roller shaft 32 of the heating roller 30, an input gear 34 of the drive transmission system D1 and a transmission gear 36 of the return gear train D2 are provided via an electromagnetic clutch 35 shown as an example of a clutch mechanism. Yes. A clutch control means 37 is connected to the electromagnetic clutch 35.

第１フレーム２５では、また、図４に示す回動部材４０が支軸４１を中心として回動自在に支持されている。この例では、回動部材４０は、樹脂により一体成形で形成されており、支軸４１上に、左右の軸間リング３３Ｌ、３３Ｒと同間隔をあけて操作レバー４２Ｌ、４２Ｒと圧接解除レバー４３Ｌ、４３Ｒが形成されるとともに、一端に欠歯ギヤ４４が形成されている。 In the first frame 25, the rotating member 40 shown in FIG. 4 is supported so as to be rotatable about the support shaft 41. In this example, the rotation member 40 is integrally formed of resin, and the operation levers 42L and 42R and the pressure release lever 43L are formed on the support shaft 41 at the same interval as the left and right inter-ring rings 33L and 33R. 43R are formed, and a missing gear 44 is formed at one end.

圧接解除レバー４３Ｌ、４３Ｒは、この発明でいう圧接解除部材であり、先端がほぼ直角に折り曲げられて楔形状につくられている。また、欠歯ギヤ４４は、外周の一部に歯のない欠歯部４４ａが設けられており、外面には偏心する位置に偏心ピン４５が立てられている。そして、その偏心ピン４５の先端と第１フレーム２５の間には、付勢部材である引っ張り付勢バネ４６が掛けられている。 The pressure release levers 43L and 43R are pressure release members as referred to in the present invention, and the tips are bent at substantially right angles and formed in a wedge shape. Further, the toothless gear 44 is provided with a toothless portion 44a having no teeth on a part of the outer periphery, and an eccentric pin 45 is provided at an eccentric position on the outer surface. A tension biasing spring 46, which is a biasing member, is hung between the tip of the eccentric pin 45 and the first frame 25.

これにより、図２に示すように、操作レバー４２Ｌ、４２Ｒは、第１フレーム２５の頂面切欠き２５ａから上向きに突出し、引っ張り付勢バネ４６の付勢力を受けて、頂面切欠き２５ａの縁部に形成した押当位置決め部２５ｂに押し当てられ、待機位置に位置決めされる。 As a result, as shown in FIG. 2, the operation levers 42L and 42R protrude upward from the top surface notch 25a of the first frame 25, receive the urging force of the tension urging spring 46, and the top surface notch 25a It is pressed against the pressing positioning part 25b formed at the edge and positioned at the standby position.

他方、圧接解除レバー４３Ｌ、４３Ｒは、加熱ローラ３０の軸間リング３３Ｌ、３３Ｒと対向する、用紙搬送の妨げとならない位置で、第２フレーム２６の頂面切欠き２６ａから上向きに突出される。また、欠歯ギヤ４４は、欠歯部４４ａを伝達ギヤ３６に向け、伝達ギヤ３６と噛み合うアイドラギヤ４７とかみ合っていない状態となっている。 On the other hand, the pressure release levers 43L and 43R protrude upward from the top surface notch 26a of the second frame 26 at a position that faces the inter-axis rings 33L and 33R of the heating roller 30 and does not hinder paper conveyance. Further, the missing gear 44 is in a state in which the missing tooth portion 44 a faces the transmission gear 36 and is not engaged with the idler gear 47 that meshes with the transmission gear 36.

なお、この例では、回動部材４０をすべて一体で構成したが、もちろん適宜別部材でつくり、組み合わせて構成してもよい。 In this example, all the rotating members 40 are integrally formed, but of course, other rotating members may be appropriately formed and combined.

一方、図２から判るように、第２フレーム２６では、互いに圧接する一対の圧接部材の他方である加圧ローラ５０がローラ軸５１を中心として回転自在に保持されている。加圧ローラ５０には、ローラ部の軸方向左右両側に、加熱ローラ３０の軸間リング３３Ｌ、３３Ｒと対向して軸間リング５２Ｌ、５２Ｒが設けられている。そして、加圧バネ５３Ｌ、５３Ｒで付勢して第２フレーム２６とともに移動され、加圧ローラ５０が加熱ローラ３０に押し当てられて定着ニップＮが形成され、その定着ニップＮが双方の軸間リング３３Ｌ、３３Ｒと軸間リング５２Ｌ、５２Ｒの当接により管理されるようになっている。 On the other hand, as can be seen from FIG. 2, in the second frame 26, the pressure roller 50, which is the other of the pair of pressure contact members that are in pressure contact with each other, is held rotatably about the roller shaft 51. The pressure roller 50 is provided with inter-axial rings 52L and 52R facing the inter-axial rings 33L and 33R of the heating roller 30 on both the left and right sides in the axial direction of the roller portion. The pressure springs 53L and 53R are urged and moved together with the second frame 26, the pressure roller 50 is pressed against the heating roller 30 to form a fixing nip N, and the fixing nip N is between the two shafts. The ring 33L, 33R and the inter-axial rings 52L, 52R are managed by contact.

他の圧接部材は、ローラに限らず、複数のローラに掛けまわす無端ベルトであってもよいし、回転部材に限らず、回転しないパッドのようなものであってもよい。また、一方の圧接部材と同様に、発熱体を備えるようなものであってもよい。 The other pressure contact members are not limited to rollers, but may be endless belts that are wound around a plurality of rollers, and are not limited to rotating members, but may be non-rotating pads. Further, like the one pressure contact member, a heating element may be provided.

図５には、駆動源からの駆動力を定着装置２０に伝達するギヤ列を示す。
図中符号６０が、駆動源である駆動モータである。駆動モータ６０の回転は、駆動伝達系Ｄ１のいくつかの中間ギヤ６１を介して入力ギヤ３４に伝達されて加熱ローラ３０が回転される。そして、加圧ローラ５０を従動回転しながら、定着ニップＮに挿入された用紙１１を搬送するとともに、定着ニップＮで熱と圧力とを加えてその用紙１１上のトナー像が定着される。また、加熱ローラ３０の回転により、復帰ギヤ列Ｄ２の伝達ギヤ３６が回転されてアイドラギヤ４７に伝達される。 FIG. 5 shows a gear train that transmits the driving force from the driving source to the fixing device 20.
Reference numeral 60 in the figure denotes a drive motor that is a drive source. The rotation of the drive motor 60 is transmitted to the input gear 34 through some intermediate gears 61 of the drive transmission system D1, and the heating roller 30 is rotated. The paper 11 inserted into the fixing nip N is conveyed while the pressure roller 50 is driven to rotate, and heat and pressure are applied to the fixing nip N to fix the toner image on the paper 11. The transmission gear 36 of the return gear train D2 is rotated by the rotation of the heating roller 30 and transmitted to the idler gear 47.

画像形成装置の使用時は、上述したように、引っ張り付勢バネ４６で付勢されて操作レバー４２Ｌ、４２Ｒが押当位置決め部２５ｂに当てられ、欠歯ギヤ４４の欠歯部４４ａがアイドラギヤ４７に対向しているので、アイドラギヤ４７の回転は欠歯ギヤ４４には伝達されない。 When the image forming apparatus is used, as described above, the operation levers 42L and 42R are urged by the pulling urging spring 46 and the pressing positioning portion 25b is applied, and the missing tooth portion 44a of the missing gear 44 is moved to the idler gear 47. Therefore, the rotation of the idler gear 47 is not transmitted to the toothless gear 44.

図６には、加熱ローラ３０と加圧ローラ５０とを離間した状態を示す。
画像形成装置の使用終了後、長期間の不使用が予想されるときや、シート搬送ジャム処理時などには、クラッチ制御手段３７で制御して駆動モータ６０の駆動を停止した所定時間後に電磁クラッチ３５を切断し、図示するように、操作レバー４２Ｌ、４２Ｒに手を掛けて手動操作で、引っ張り付勢バネ４６の付勢力に抗して回動部材４０を支軸４１を中心として矢印ａ方向に回動する。 FIG. 6 shows a state where the heating roller 30 and the pressure roller 50 are separated from each other.
When it is expected that the image forming apparatus will not be used for a long period of time after the end of use of the image forming apparatus or during sheet conveyance jam processing, the electromagnetic clutch is controlled by the clutch control means 37 and a predetermined time after the drive motor 60 stops driving. 35, as shown in the drawing, the operation levers 42L and 42R are manually operated and the rotation member 40 is moved around the support shaft 41 in the direction of arrow a against the urging force of the tension urging spring 46. To turn.

すると、その回動部材４０に設ける圧接解除レバー４３Ｌ、４３Ｒを待機位置から圧接解除位置へと移動して、先端の楔形状部分を、加熱ローラ３０の軸間リング３３Ｌ、３３Ｒと加圧ローラ５０の軸間リング５２Ｌ、５２Ｒ間に挿入し、加圧ローラ５０を退避して加熱ローラ３０と加圧ローラ５０の圧接を解除するとともに、欠歯ギヤ４４を回転して欠歯ギヤ４４とアイドラギヤ４７とをかみ合わす。すなわち、定着装置２０には、一対の圧接部材の圧接を解除する圧接解除機構が設けられている。 Then, the pressure release levers 43L and 43R provided on the rotating member 40 are moved from the standby position to the pressure release position, and the wedge-shaped portion at the tip is moved between the inter-axial rings 33L and 33R of the heating roller 30 and the pressure roller 50. Are inserted between the inter-ring rings 52L and 52R, the pressure roller 50 is retracted to release the pressure contact between the heating roller 30 and the pressure roller 50, and the missing gear 44 is rotated to cause the missing gear 44 and the idler gear 47 to rotate. Engage with. That is, the fixing device 20 is provided with a pressure release mechanism that releases the pressure contact between the pair of pressure members.

このとき、加圧バネ５３Ｌ、５３Ｒの付勢力に基づき両軸間リング間で圧接解除レバー４３Ｌ、４３Ｒを保持する力を、引っ張り付勢バネ４６の付勢力に基づき回動部材４０を回動して圧接解除レバー４３Ｌ、４３Ｒを待機位置へと戻そうとする力よりも大きくする。これにより、加熱ローラ３０と加圧ローラ５０との離間状態を保つことができる。 At this time, the rotation member 40 is rotated based on the urging force of the tension urging spring 46 by using the force for holding the pressure contact release levers 43L and 43R between the rings between the two shafts based on the urging force of the pressure springs 53L and 53R. Thus, the pressure release levers 43L and 43R are set larger than the force for returning to the standby position. Thereby, the separation state of the heating roller 30 and the pressure roller 50 can be maintained.

なお、図示例では、加熱ローラ３０および加圧ローラ５０のローラ部の軸方向左右両側に軸間リング３３Ｌ、３３Ｒおよび５２Ｌ、５２Ｒを設けてそれらの間に圧接解除部材を挿入してローラ間の圧接を解除したが、軸間リングに限らず、例えばローラ軸に当てて一対の圧接部材の少なくとも一方を移動して一対の圧接部材を離間するようにしてもよい。 In the illustrated example, inter-axial rings 33L, 33R and 52L, 52R are provided on both the left and right sides in the axial direction of the roller portions of the heating roller 30 and the pressure roller 50, and a pressure release member is inserted between them. Although the press contact is released, the pair of press contact members may be separated by moving at least one of the pair of press contact members against the roller shaft.

再び画像形成装置の使用を開始するときには、クラッチ制御手段３７により駆動モータ６０の駆動を開始する所定時間前に電磁クラッチ３５が接続され、その後、駆動モータ６０の駆動により駆動モータ６０の駆動が駆動伝達系Ｄ１を介して伝達されて加熱ローラ３０が回転されるとき、同時に復帰ギヤ列Ｄ２の伝達ギヤ３６が回転されてその回転がアイドラギヤ４７を介してそれに噛み合う欠歯ギヤ４４に伝達され、駆動モータ６０のからの駆動力が伝達されて回動部材４０が回動される。 When the use of the image forming apparatus is started again, the electromagnetic clutch 35 is connected a predetermined time before the drive of the drive motor 60 is started by the clutch control means 37, and then the drive of the drive motor 60 is driven by the drive of the drive motor 60. When the heating roller 30 is rotated by being transmitted through the transmission system D1, the transmission gear 36 of the return gear train D2 is rotated at the same time, and the rotation is transmitted through the idler gear 47 to the toothless gear 44 that meshes with it. The driving force from the motor 60 is transmitted and the rotating member 40 is rotated.

そして、操作レバー４２Ｌ、４２Ｒの回動とともに圧接解除レバー４３Ｌ、４３Ｒが両軸間リング間から退避され、圧接解除位置から待機位置に戻されて、再度引っ張り付勢バネ４６の付勢力で操作レバー４２Ｌ、４２Ｒが押当位置決め部２５ｂに押し当てられて位置決めされ、欠歯ギヤ４４の欠歯部４４ａがアイドラギヤ４７に対向されて欠歯ギヤ４４とアイドラギヤ４７のかみ合いが解除され、欠歯ギヤ４４に対するそれ以上の回転伝達が遮断されるとともに、加熱ローラ３０に対して加圧ローラ５０が押し当てられる図５に示す状態とされる。すなわち、定着装置２０には、一対の圧接部材を圧接状態に復帰する圧接復帰機構が設けられている。 Then, as the operation levers 42L and 42R rotate, the pressure contact release levers 43L and 43R are retracted from between the rings between the two shafts, returned from the pressure contact release position to the standby position, and again operated by the biasing force of the tension bias spring 46. 42L and 42R are pressed against the pressing positioning portion 25b for positioning, and the missing tooth portion 44a of the missing gear 44 is opposed to the idler gear 47 so that the engagement between the missing tooth gear 44 and the idler gear 47 is released. 5 is blocked, and the pressure roller 50 is pressed against the heating roller 30 as shown in FIG. That is, the fixing device 20 is provided with a pressure contact return mechanism that returns the pair of pressure contact members to the pressure contact state.

ところで、図１に示す画像形成装置本体１０には、通常、ジャム処理、部品交換、修理などを行うときの便宜のため、例えば用紙搬送経路１５を開放する外装カバーが開閉自在に設けられている。この場合には、外装カバーを開いたとき、クラッチ制御手段３７で制御して電磁クラッチ３５を切断するようにするとよい。 Incidentally, in the image forming apparatus main body 10 shown in FIG. 1, for example, an exterior cover that opens the paper conveyance path 15 is normally provided to be openable and closable for convenience when performing jam processing, parts replacement, repair, and the like. . In this case, when the exterior cover is opened, the electromagnetic clutch 35 may be disconnected by being controlled by the clutch control means 37.

この発明によりシート搬送装置が備えられている画像形成装置の全体概略構成図である。1 is an overall schematic configuration diagram of an image forming apparatus provided with a sheet conveying device according to the present invention. 図１にこの発明によるシート搬送装置の一例として示す定着装置の概略構成斜視図である。FIG. 1 is a schematic perspective view of a fixing device shown in FIG. 1 as an example of a sheet conveying device according to the present invention. その定着装置に設ける加熱ローラの一端部の拡大斜視図である。FIG. 4 is an enlarged perspective view of one end portion of a heating roller provided in the fixing device. その定着装置に設ける回動部材の斜視図である。It is a perspective view of the rotation member provided in the fixing device. 駆動源からの駆動力を定着装置に伝達するギヤ列構成図である。It is a gear train block diagram which transmits the driving force from a drive source to a fixing device. その加熱ローラと加圧ローラとを離間した状態を示す図である。It is a figure which shows the state which spaced apart the heating roller and the pressure roller. 従来の定着装置の概略構成図である。It is a schematic block diagram of the conventional fixing device.

符号の説明Explanation of symbols

２０定着装置（シート搬送装置）
２５第１フレーム
２６第２フレーム
３０加熱ローラ（圧接部材）
３３Ｌ、３３Ｒ軸間リング
３５電磁クラッチ（クラッチ機構）
３７クラッチ制御手段
４０回動部材
４１支軸
４２Ｌ、４２Ｒ操作レバー
４３Ｌ、４３Ｒ圧接解除レバー（圧接解除部材）
４４欠歯ギヤ
４４ａ欠歯部
４５偏心ピン
４６引っ張り付勢バネ（付勢部材）
４７アイドラギヤ
５０加圧ローラ（圧接部材）
５２Ｌ、５２Ｒ軸間リング
５３Ｌ、５３Ｒ加圧バネ
６０駆動モータ（駆動源）
Ｄ１駆動伝達系
Ｄ２復帰ギヤ列
Ｎ定着ニップ

20 Fixing device (sheet conveying device)
25 1st frame 26 2nd frame 30 Heating roller (pressure contact member)
33L, 33R Inter-shaft ring 35 Electromagnetic clutch (clutch mechanism)
37 Clutch control means 40 Rotating member 41 Support shaft 42L, 42R Operation lever 43L, 43R Pressure release lever (pressure contact release member)
44 missing tooth gear 44a missing tooth portion 45 eccentric pin 46 tension biasing spring (biasing member)
47 idler gear 50 pressure roller (pressure contact member)
52L, 52R Axle ring 53L, 53R Pressure spring 60 Drive motor (drive source)
D1 Drive transmission system D2 Return gear train N Fixing nip

Claims

互いに圧接する一対の圧接部材間の圧接ニップにシートを挿入して少なくとも一方の圧接部材を回転することによりシートを搬送するシート搬送装置において、
使用終了後に、手動操作して支軸を中心として回動部材を回動し、その回動部材に設ける圧接解除部材を待機位置から圧接解除位置に移動したとき、その圧接解除部材によって少なくとも一方の圧接部材を退避して前記一対の圧接部材の圧接を解除する圧接解除機構と、
使用開始時、駆動源の駆動力を伝達して前記圧接部材を回転するとき、同時に復帰ギヤ列を介して前記駆動源の駆動力を前記回動部材に伝達して前記圧接解除部材を前記圧接解除位置から前記待機位置に戻し、前記一対の圧接部材を圧接状態に復帰する圧接復帰機構と、
が備えられていることを特徴とするシート搬送装置。 In a sheet conveying apparatus that conveys a sheet by inserting a sheet into a pressure nip between a pair of pressure members that are in pressure contact with each other and rotating at least one pressure member,
After completion of use, when the rotation member is rotated manually around the support shaft and the pressure release member provided on the rotation member is moved from the standby position to the pressure release position, at least one of the pressure release members is moved by the pressure release member. A pressure release mechanism that retracts the pressure contact member to release the pressure contact between the pair of pressure contact members;
At the start of use, when the pressure contact member is rotated by transmitting the drive force of the drive source, simultaneously, the drive force of the drive source is transmitted to the rotating member via the return gear train and the pressure release member is A pressure return mechanism that returns the release position to the standby position and returns the pair of pressure contact members to a pressure contact state;
A sheet conveying apparatus comprising:

前記復帰ギヤ列に、欠歯ギヤと、それにかみ合って前記駆動源からの駆動力を伝達するアイドラギヤとが設けられており、前記欠歯ギヤには、前記圧接解除部材が前記待機位置に戻ったとき、前記アイドラギヤとのかみ合いを解除する欠歯部が形成されていることを特徴とする、請求項１に記載のシート搬送装置。 The return gear train is provided with a missing gear and an idler gear that meshes with the idler gear and transmits the driving force from the drive source. The pressure release member returns to the standby position in the missing gear. The sheet conveying device according to claim 1, wherein a missing tooth portion for releasing engagement with the idler gear is formed.

前記回動部材を付勢して前記圧接解除部材を前記待機位置に保持する付勢部材が設けられていることを特徴とする、請求項１または２に記載のシート搬送装置。 The sheet conveying apparatus according to claim 1, wherein a biasing member that biases the rotating member to hold the pressure-contact releasing member at the standby position is provided.

前記付勢部材の付勢力で前記回動部材を押し当てて前記圧接解除部材を前記待機位置に位置決めする押当位置決め部が設けられていることを特徴とする、請求項３に記載のシート搬送装置。 4. The sheet conveyance according to claim 3, further comprising a pressing positioning portion that presses the rotating member with an urging force of the urging member to position the pressure release member at the standby position. apparatus.

前記駆動源の駆動力を伝達して前記圧接部材を回転する駆動伝達系に対して、前記復帰ギヤ列を切り離すクラッチ機構が設けられていることを特徴とする、請求項１ないし４のいずれか１に記載のシート搬送装置。 The clutch mechanism for separating the return gear train is provided for a drive transmission system that transmits the driving force of the driving source to rotate the pressure contact member. The sheet conveying apparatus according to 1.

前記一対の圧接部材として、シートを加熱する加熱部材と、それに押し当てて定着ニップを形成する加圧部材とが備えられている定着装置であることを特徴とする、請求項１ないし５のいずれか１に記載のシート搬送装置。 6. The fixing device according to claim 1, wherein the fixing device includes a heating member that heats the sheet and a pressure member that is pressed against the pressure member to form a fixing nip. The sheet conveying apparatus according to claim 1.

請求項１ないし６のいずれか１に記載のシート搬送装置が備えられていることを特徴とする画像形成装置。 An image forming apparatus comprising the sheet conveying device according to claim 1.

前記駆動源の駆動力を伝達して前記圧接部材を回転する駆動伝達系に対して、前記復帰ギヤ列を切り離すクラッチ機構が設けられており、そのクラッチ機構を、前記駆動源の駆動を開始する所定時間前に接続し、前記駆動源の駆動を停止した所定時間後に切断するように制御するクラッチ制御手段が備えられていることを特徴とする、請求項７に記載の画像形成装置。 A clutch mechanism for separating the return gear train is provided for a drive transmission system that transmits the driving force of the drive source to rotate the pressure contact member, and the clutch mechanism starts driving the drive source. The image forming apparatus according to claim 7, further comprising a clutch control unit that is connected before a predetermined time and controls to be disconnected after a predetermined time after driving of the drive source is stopped.

前記駆動源の駆動力を伝達して前記圧接部材を回転する駆動伝達系に対して、前記復帰ギヤ列を切り離すクラッチ機構が設けられており、そのクラッチ機構を、画像形成装置本体の外装カバーを開いたとき切断するように制御するクラッチ制御手段が備えられていることを特徴とする、請求項７または８に記載の画像形成装置。 A clutch mechanism for separating the return gear train is provided for a drive transmission system that transmits the driving force of the drive source to rotate the pressure contact member, and the clutch mechanism is attached to an exterior cover of the image forming apparatus main body. The image forming apparatus according to claim 7, further comprising a clutch control unit that controls to disconnect when opened.