JP2017223801A - Support structure for opening/closing member, sheet feeding device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a support structure for an opening/closing member in which a support shaft of the opening/closing member can be stably held even in the case where a difference between an installation angle and a rotation range during use is small.SOLUTION: A right door of a sheet feeding device can be opened/closed at a predetermined opening angle with a closing position defined as a reference, and swung along an installation angle greater than the opening angle, such that a support shaft 62 is engaged to a front bearing 72. The front bearing 72 includes a bearing part 72a which is opened in an opening 72b. The support shaft 62 includes: a first arcuate part a1 and a second arcuate part a2 in slide contact with the bearing part 72a; and a first planar part b1 and a second planar part b2 that are formed equal to or smaller than a width of the opening 72b. A position of the support shaft 62 held by the bearing part 72a is offset relatively to a position of the support shaft 62 in passing the opening 72b in accordance with shapes of the support shaft 62 and the front bearing 72, such that the support shaft 62 and the bearing part 72a are engaged deep.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a support structure for an open / close member that supports an open / close member that can be opened and closed with respect to a main body, and a sheet feeding apparatus and an image forming apparatus including the support structure.

  2. Description of the Related Art Conventionally, some image forming apparatuses such as copying machines are provided with an opening / closing member that can be opened and closed with respect to the apparatus main body. Examples of such an opening / closing member include a cover member that is opened / closed for the purpose of exchanging components inside the apparatus main body, removing a sheet jammed in the sheet conveyance path, and the like.

  Patent Document 1 discloses a printer cover assembly structure in which a hinge shaft of a printer cover is assembled to a main body case by fitting into a long hole provided in the main body case. In this assembly structure, the hinge shaft is provided with a chamfered portion and is formed in a non-cylindrical shape. On the other hand, the main body case is formed with an attaching / detaching groove that allows the hinge shaft to be attached to and detached from the elongated hole when the printer cover is at a predetermined angular position.

JP-A-11-286258

  By the way, in the configuration in which the hinge shaft is engaged with the elongated hole as in the printer cover described in Patent Document 1, the printer cover may be wobbled along the elongated hole when a force is applied to the printer cover from the outside. is there. In addition, it is necessary to arrange peripheral members while avoiding the movement locus when the printer cover moves along the elongated hole, which hinders downsizing of the apparatus.

  Therefore, by providing an engagement portion that engages with the support shaft of the opening / closing member with an inner peripheral portion formed along the inscribed circle and an opening portion that opens outward from the inner peripheral portion, the support shaft is A configuration that supports the rotation and the non-radial movement is conceivable. That is, when the opening / closing member is moved along a predetermined mounting angle, the non-cylindrical support shaft can be moved through the opening, and when the opening / closing member is rotated from the mounting angle to the rotation range during use, the support shaft A configuration in which is held by the inner periphery is conceivable.

  However, in such a configuration, when the difference between the mounting angle and the rotation range during use is small, the open / close member may fall off the main body. For example, when an open / close member is placed on the side of a device whose size in the vertical direction is restricted, such as an optional feeder that is added to the lower part of the image forming device, to avoid interference of components during assembly, On the other hand, it may be mounted at a mounting angle smaller than 90 degrees. In such a case, even if the support shaft is engaged with the engagement portion along the mounting angle and then rotated to the rotation range during use, the inner periphery of the support shaft and the engagement portion The peripheral portion was not sufficiently engaged, and the support shaft was easily disengaged from the engaging portion.

  SUMMARY An advantage of some aspects of the invention is that it provides a support structure for an opening / closing member that can stably support the opening / closing member, and a sheet feeding apparatus and an image forming apparatus including the support structure.

  One aspect of the present invention is a support structure of an opening / closing member that supports the opening / closing member so that the opening / closing member can be opened / closed with respect to a main body, and the opening / closing member exceeds a predetermined opening angle on the basis of the closed state A restricting means for restricting the rotation, an engaging portion provided on one of the main body and the opening / closing member, and an attachment provided on the other of the main body and the opening / closing member, wherein the opening / closing member is larger than the opening angle. A support shaft that is removably engaged with the engagement portion by being swung along an angle, and the engagement portion includes an inner peripheral portion formed along an inscribed circle, An opening that opens in a radial direction outward from the inner peripheral portion with a width smaller than the diameter of the inscribed circle, and the support shaft has an outer diameter larger than the width of the opening. A circumscribing portion that slidably contacts an inner peripheral portion, and a width equal to or less than the width of the opening as viewed from the mounting angle And the position of the shaft center of the support shaft in a state where the circumscribed portion is held on the inner peripheral portion is the center of the shaft when passing through the opening. The engagement portion and the support shaft are formed so as to be offset in a direction in which the opening / closing member is moved from the mounting angle toward the opening angle with respect to a position when viewed from the mounting angle. And

  According to the support structure of the opening and closing member according to the present invention, the opening and closing member can be stably supported on the main body.

1 is a schematic diagram illustrating a configuration of an image forming apparatus according to the present disclosure. (A) is a perspective view of a sheet feeding apparatus, (b) is a perspective view of the sheet feeding apparatus in a state where the right door is opened. (A) is a perspective view of the sheet feeding apparatus with the right door removed, and (b) is an enlarged view in which the periphery of the back bearing is enlarged. (A) is a perspective view of the sheet feeding apparatus with the right door removed, and (b) is an enlarged view in which the periphery of the front bearing is enlarged. (A) is the perspective view which looked at the right door from the outside, (b) is the perspective view which looked from the inside. Sectional drawing of the sheet feeding apparatus which shows the 1st step of the assembly | attachment operation | movement of the right door which concerns on a 1st Example. Sectional drawing of the sheet feeding apparatus which shows the 2nd step of the assembly | attachment operation | movement of the right door which concerns on a 1st Example. Sectional drawing of the sheet feeding apparatus which shows the state which has the right door which concerns on a 1st Example in an open position. (A) is sectional drawing which shows the structure of the hinge mechanism based on 1st Example, (b) is a schematic diagram which shows the shape of a support shaft. Sectional drawing of the sheet feeding apparatus which shows the state which has the right door which concerns on a 1st Example in a closed position. (A) is sectional drawing which shows the structure of the hinge mechanism based on 2nd Example, (b) is a schematic diagram which shows the shape of a support shaft. Sectional drawing of the sheet feeding apparatus which concerns on the modification from which the shape of a support shaft differs. (A) is sectional drawing which shows the state which engaged the support shaft of the right door with the bearing part in the sheet feeding apparatus which concerns on a conventional structure, (b) is a cross section which shows the state in which the right door is in an open position. (C) is sectional drawing which shows the state which has a right door in a closed position. (A) is sectional drawing which shows the state which engaged the support shaft of the right door with the bearing part in the sheet feeding apparatus which concerns on a comparative example, (b) is a cross section which shows the state in which the right door is in an open position. Figure.

  Hereinafter, a support structure for an opening / closing member according to the present disclosure, and a sheet feeding apparatus and an image forming apparatus including the support structure will be described with reference to the drawings. An image forming apparatus 1 according to the present disclosure is a full-color laser beam printer that forms an image on a sheet S based on image information input from an external device such as a personal computer. However, the sheet S indicates a thin-layer recording medium such as paper such as paper and an envelope, a plastic film such as an overhead projector sheet (OHT), or a cloth.

  As shown in FIG. 1, the image forming apparatus 1 includes an image forming unit 1B that forms an image on a sheet S, a fixing unit 20 that fixes an image on the sheet S, and the like inside the apparatus main body 1A. Above the apparatus main body 1A, an image reading device 2 that reads image data of a document is disposed in a posture in which the document placement surface is substantially horizontal. A discharge tray 23 is provided in a sheet discharge space formed between the image reading apparatus 2 and the apparatus main body 1A. Further, the apparatus main body 1A is provided with a sheet feeding unit 30 that feeds the sheet S to the image forming unit 1B. The sheet feeding unit 30 includes one or a plurality (four in the illustrated example) of sheet feeding devices 31, 32, 33, and 34 disposed in the lower portion of the apparatus main body 1A, and a manual feeding device (not shown). Including.

  The image forming unit 1B as an image forming unit has a so-called four-drum full-color configuration including a laser scanner 10, four process cartridges 1a, 1b, 1c, and 1d, and an intermediate transfer unit 1C. These cartridges form yellow, magenta, cyan, and black toner images, respectively. Each process cartridge 1a, 1b, 1c, 1d includes a photosensitive drum 12, which is a photosensitive member, a charger 13, a developing device 14, a cleaner (not shown), and the like. A toner cartridge 15 containing toner of each color is detachably mounted on the apparatus main body 1A above the image forming unit 1B.

  The intermediate transfer unit 1C is configured by winding an intermediate transfer belt 16 as an intermediate transfer member around a driving roller 16a, a tension roller 16b, and the like, and is disposed above the four process cartridges 1a, 1b, 1c, and 1d. . The intermediate transfer belt 16 is rotated counterclockwise in the figure by a driving roller 16a driven by a driving unit (not shown) while being in contact with the photosensitive drums 12 of the cartridges 1a, 1b, 1c, and 1d. The intermediate transfer unit 1 </ b> C includes a primary transfer roller 17 that is in contact with the inner peripheral surface of the intermediate transfer belt 16 at a position facing each photosensitive drum 12. Further, the image forming unit 1B includes a secondary transfer roller 19 that contacts the outer peripheral surface of the intermediate transfer belt 16 at a position facing the drive roller 16a.

  In each of the above-described process cartridges 1a, 1b, 1c, and 1d, an electrostatic latent image is drawn on the surface of the photosensitive drum 12 by the laser scanner 10, and then toner is supplied from the developing unit 14, thereby negative polarity. A toner image of each color charged is formed. These toner images are subjected to multiple transfer (primary transfer) to the intermediate transfer belt 16 by applying a positive transfer bias voltage to the primary transfer roller 17 to form a full color toner image on the intermediate transfer belt 16. Is done.

  In parallel with such a toner image forming process, the sheet S fed from the sheet feeding unit 30 is conveyed toward the registration roller pair 18 and the skew feeding is corrected by the registration roller pair 18. . The registration roller pair 18 has a sheet S on the secondary transfer portion formed between the intermediate transfer belt 16 and the secondary transfer roller 19 in accordance with the transfer timing of the full-color toner image formed on the intermediate transfer belt 16. Transport. The toner image carried on the intermediate transfer belt 16 is secondarily transferred to the sheet S by applying a positive transfer bias voltage to the secondary transfer roller 19.

  When the sheet S to which the toner image has been transferred is heated and pressed in the fixing unit 20, the toner image is fixed on the sheet S as a color image. The sheet S on which the image is fixed is discharged and stacked on the discharge tray 23 by the discharge roller pair 25a. When images are formed on both sides of the sheet S, the sheet S that has passed through the fixing unit 20 is switched back by a pair of reversing rollers 25b that can be rotated in the normal direction. Then, when the sheet S is conveyed again to the image forming unit 1B via the reconveying path R1, an image is formed on the back surface of the sheet S and is discharged to the discharge tray 23 to complete the duplex printing.

[Sheet feeding device]
Next, the sheet feeding devices 31, 32, 33, and 34 that constitute the sheet feeding unit 30 will be described. As shown in FIG. 1, the sheet feeding devices 31, 32, 33, and 34 are respectively feeding cassettes 41, 42, 43, and 44 serving as storage units for storing the sheets S, and feeding for feeding the sheets S. Feeding units 51, 52, 53 and 54 as feeding means are provided. Each feeding unit has a so-called retard separation system configuration including a pickup roller 5a serving as a feeding member, a feed roller 5b serving as a conveying member, and a retard roller 5c serving as a separating member.

  While the sheet feeding apparatus 31 is provided as standard on the apparatus main body 1A, the sheet feeding apparatuses 32, 33, and 34 are configured as optional feeders that can be added one step at a lower portion of the apparatus main body 1A. The sheet feeding devices 32, 33, and 34 have substantially the same configuration, and are electrically and mechanically connected to the apparatus main body 1A, so that the sheet S can be fed. Each of the sheet feeding apparatuses 31, 32, 33, and 34 includes a pair of conveyance rollers 81, 82, 83, and 84 that can convey the sheet S upward. The sheet S supplied from the feeding cassette is sequentially delivered through the conveyance roller pairs 81, 82, 83, and 84, and is conveyed toward the image forming unit 1B through a vertical path extending in the vertical direction.

  Hereinafter, the configuration of the option feeder will be described using the sheet feeding device 32 as an example. As shown in FIG. 2A, the sheet feeding apparatus 32 is configured by assembling a feeding cassette 42, a right door 60, and the like to a feeding frame 32A that is a main body.

  A plurality of positioning pins 121 are fixed on the upper surface of the feeding frame 32A, and the sheet feeding device 32 is positioned by engaging with pin holes provided on the lower surface of the apparatus main body 1A or another sheet feeding apparatus. The feeding frame 32A is electrically connected to the power source and the control unit of the apparatus main body 1A by being connected to the apparatus main body 1A by a coupling tool (not shown).

  The feeding cassette 42 has a gripping portion 42a that is gripped by the user, and is attached to the feeding frame 32A so that it can be pulled out toward the front side of the apparatus main body 1A. The feeding cassette 42 is provided with a support plate that supports the sheet S, an elevating mechanism that raises and lowers the support plate, and a regulation plate that controls the position of the sheet S supported by the support plate (all not shown). Yes.

  As shown in FIGS. 2A and 2B, the right door 60 as an opening / closing member constitutes a side portion of the sheet feeding device 32 (a right side portion when the image forming apparatus 1 is viewed from the front). Yes. The right door 60 includes a gripping portion 60a that is gripped by the user, and is configured to be openable and closable outward (rightward) of the apparatus main body 1A.

  As shown in FIG. 5 (b), one roller 82b of the conveyance roller pair 82 is attached to the right door 60 and faces the other roller 82a supported by the feeding frame 32A (FIG. 2 ( b)). The inner surface of the right door 60 constitutes a guide surface 66 that guides the sheet S conveyed by the conveying roller pair 82.

  On the inner side of the right door 60, a double-sided guide 92 configured to form a vertical path facing the guide surface 66 and to open outward as the right door 60 is opened and closed is provided (FIG. 2). (See (b)). Further, the double-sided guide 92 forms a feeding path for guiding the sheet fed from the feeding unit 52 on the side surface opposite to the guide surface 66. Therefore, in the case of a sheet jam or the like, the vertical path and the feeding path are opened by opening the right door 60, and the jammed sheet can be easily removed.

[Right door support structure]
Next, a support structure for supporting the right door 60 on the feeding frame 32A will be described. As shown in FIGS. 5A and 5B, the right door 60 has support shafts 61 and 62 that protrude toward the back side (arrow R) and the front side (arrow F) of the image forming apparatus 1, respectively. Is provided. On the other hand, as shown in FIGS. 3A and 4A, the feed frame 32 </ b> A has a back bearing 71 that supports the back support shaft 61 and a front bearing that supports the front support shaft 62. 72 is provided. The support shafts 61 and 62, the back bearing 71, and the front bearing 72 constitute a hinge mechanism that supports the right door 60 in a rotatable and detachable manner.

  As shown in FIG. 3B, the back bearing 71 includes a bearing portion 71a having a cylindrical inner peripheral surface and a rib 71b that reinforces the bearing portion 71a, and is fixed to the feeding frame 32A by screws or the like. ing. On the other hand, the front bearing 72 includes a bearing portion 72a having an inner peripheral surface having a circular arc cross section (C shape). The bearing portions 71 a and 72 a of the back bearing 71 and the front bearing 72 hold the support shafts 61 and 62, thereby supporting the right door 60 so as to be rotatable about the support shafts 61 and 62.

  The sheet feeding device 32 is provided with a stopper 73 that is a locking portion and a rotation guide 63 that is a locked portion, as restricting means for restricting the rotation range of the opening and closing member. As shown in FIGS. 5A and 5B, the rotation guide 63 is disposed on the side portion on the near side of the right door 60, and an arcuate guide groove 63 a centering on the support shaft 62 is formed. It is a plate-like member. As shown in FIGS. 4A and 4B, the stopper 73 is fixed to the feeding frame 32 </ b> A and engages with the guide groove 63 a by elastically deforming the rotation guide 63.

  The right door 60 rotates beyond a predetermined opening angle with the stopper 73 engaged with the rotation guide 63 abutting against the end of the guide groove 63a as a reference (0 degree) when the right door 60 is closed. Is restricted from moving. As a result, the right door 60 is opened and closed between the closed position (FIG. 2A) and the open position (FIG. 2B) in a state assembled to the feeding frame 32A. The restricting means may be configured by software such as a method based on rotation control of a motor that is drivingly connected to the support shafts 61 and 62 without being mechanically locked.

  As shown in FIGS. 5A and 5B, hooks 64 and 64 for holding the right door 60 in the closed position are provided on both sides of the right door 60. The hook 64 is biased by a hook spring 65 and engages with a locking portion (not shown) fixed to the feeding frame 32 </ b> A as the right door 60 is closed. When the right door 60 is in the closed position, the rollers 82a and 82b of the conveying roller pair 82 are in pressure contact with each other, and the hook 64 moves the right door 60 in the closed position against the nip pressure of the conveying roller pair 82. Lock. Further, the hook 64 is configured to be disengaged from the locking portion of the feeding frame 32A in conjunction with the operation of the grip portion 60a of the right door 60.

  Subsequently, an assembly configuration of the right door 60 with respect to the feeding frame 32A will be described in detail. As described above, the bearing portion 72a of the front bearing 72 is partially opened in the circumferential direction, and after the support shaft 61 on the back side is fitted to the back bearing 71, the front side along a predetermined mounting angle. The support shaft 62 is configured to be engaged with the front bearing 72 by moving the support shaft 62.

  Here, in the conventional configuration shown in FIGS. 13A to 13C, the mounting angle is set to 90 degrees with respect to the angle of the closed position, and the opening angle that is the angle of the open position is set to 50 degrees. It was. However, this conventional configuration is the same as that of the sheet feeding device 32 according to the present embodiment except that the shapes of the support shaft 162 and the front bearing 172 are different from those of the support shaft 62 and the front bearing 72. In this configuration, when the right door 160 is swung along the mounting angle of 90 degrees, the support shaft 162 is engaged with the front bearing 172 (FIG. 13A). Then, when the right door 160 is locked by the stopper in a state where it is lifted by 40 degrees from the mounting angle to the opening angle, the opening position (FIG. 13B) and the closing position (FIG. 13C) are changed. It can be opened and closed between.

  As shown in FIG. 13A, the support shaft 162 has a shape in which a part of the shaft shape is cut out by two substantially parallel planes called two-sided or I-cut. With such a shape, the support shaft 162 can pass through the opening 172b of the front bearing 172 when the right door 160 is swung along the mounting angle. Further, by lifting the right door 160 to the opening angle after the support shaft 162 contacts the bearing portion 172a of the front bearing 172, the support shaft 162 is engaged with the bearing portion 272a so as not to be disengaged. In other words, using the difference between the mounting angle and the opening angle, the support shaft 162 can be engaged and disengaged from the bearing portion 172a when the right door 160 faces the mounting angle, and the right door 160 faces the opening angle. The support shaft 162 is configured to be locked to the bearing portion 172a.

  Incidentally, for the purpose of securing a space for removing the jam sheet, it is preferable that the rotation center of the right door (opening / closing member) is close to the bottom of the feeding frame 32A. In addition, it is desirable that the sheet feeding device 32 as an optional feeder has a vertical size (height) as small as possible. In this case, when the right door is assembled, the mounting angle of the right door may be set to be smaller than 90 degrees in order to avoid interference with the bottom frame 32F (see FIG. 4A) of the feeding frame 32A. Conceivable. For example, as shown in FIG. 14A, it is conceivable to form the front bearing 272 so that the mounting angle of the right door 260 is 70 degrees. In this case, as shown in FIG. 14B, the rotation guide 263 is locked to the stopper 273 when the right door 260 is lifted by 20 degrees to the opening angle of 50 degrees.

  However, when the difference between the mounting angle and the opening angle of the right door 260 is small as described above, the right door 260 may be unintentionally dropped from the feeding frame 32A. In the comparative example shown in FIGS. 14A and 14B, when the right door 260 is in the open position, the outer peripheral surface of the support shaft 262 is 20 degrees, which is the difference between the mounting angle and the opening angle with respect to the bearing portion 272a. Engage with minute amount y. However, the amount of engagement refers to the width of the portion where the bearing portion 272a overlaps the front side of the support shaft 262 when viewed from the mounting angle, which is the engagement / disengagement direction of the support shaft 262. Is deeply engaged with the bearing portion 272a. When the shaft diameter of the support shaft and the opening width of the bearing portion are equal, the hook amount y corresponding to the rotation of the support shaft 262 by 20 degrees is as in the conventional configuration shown in FIGS. 13 (a) to (c). It becomes smaller than the amount of hook corresponding to the rotation of 40 degrees. Therefore, even if the support shaft 262 is rotated from the mounting angle to the opening angle in the comparative example, the arc portion of the support shaft 262 and the bearing portion 272a are not sufficiently engaged. In this case, for example, when an impact is applied to the right door 260, the support shaft 262 of the right door 260 in the open position may be disengaged from the front bearing 272.

  Therefore, in the support structure for the opening / closing member according to the present disclosure, the hinge mechanism is arranged so that the center position of the support shaft after assembly is offset with respect to the movement locus of the support shaft when the opening / closing member is assembled. Configure. Hereinafter, examples to which the present technology is applied will be described.

  First, the detailed configuration of the hinge mechanism according to the first embodiment will be described with reference to FIGS. As shown in FIGS. 9 (a) and 9 (b), the support shaft 62 according to the present embodiment includes an arc-shaped first arc portion a1 and second arc portion a2, and a planar first plane portion b1 and first arc portion. It is comprised by the 2 plane part b2. The outer diameters of the first arc part a1 and the second arc part a2 are larger than the opening width of the opening part 72b of the front bearing 72, and are approximately the same diameter as the inner diameter of the bearing part 72a of the front bearing 72. That is, the first arc portion a1 and the second arc portion a2 constitute a circumscribed portion of the support shaft 62, and are in sliding contact with the bearing portion 72a that is the inner peripheral portion of the front bearing 72.

  On the other hand, the first plane part b1 and the second plane part b2 are formed in parallel to each other with the axis center O1 in between, and are located inside the circumscribed circle of the first arc part a1 and the second arc part a2. However, the shaft center O <b> 1 indicates the position of the rotation center of the support shaft 62 when the support shaft 62 is supported by the front bearing 72. The 1st plane part b1 and the 2nd plane part b2 comprise the small diameter part formed in a radial inside rather than a circumscribed part. The distance (Z1 + Z2) between the first plane part b1 and the second plane part b2 is set to be equal to or less than the width of the opening 72b.

  The opening 72b of the front bearing 72 has an opening width smaller than the diameter of the inscribed circle of the bearing 72a, and is formed so as to open from the center position of the bearing 72a toward the mounting angle (70 degrees). Further, the front bearing 72 is provided with a guide portion 72c extending from the lower peripheral edge of the opening 72b along an angle of 70 degrees with respect to the direction of gravity. The guide portion 72c contacts the second flat surface portion b2 of the support shaft 62, and guides the support shaft 62 toward the opening 72b along the mounting angle.

  In the present embodiment, as shown in FIG. 9B, the support shaft 62 is formed asymmetrically with respect to the axial center O1. That is, the distance Z1 from the axis center O1 to the first plane part b1 and the distance Z2 from the axis center O1 to the second plane part b2 are set to different values, and the first plane part b1 and the second plane part b2 are set. Is offset with respect to the axial center O1.

  At this time, as the offset direction of the first plane part b1 and the second plane part b2, with respect to the direction perpendicular to these planes, one side and the other side (the upper side in FIGS. 9A and 9B) Two directions (lower side) are conceivable. Here, when the right door 60 is assembled, the support shaft 62 is engaged with the bearing portion 72a along the mounting angle (70 degrees) and then lifted upward to the opening angle (50 degrees). Therefore, it is preferable that the first flat surface portion b1 and the second flat surface portion b2 are offset in the direction in which the right door 60 is moved from the mounting angle toward the opening angle as viewed from the mounting angle, that is, upward. In accordance with this, the first flat surface portion b1 positioned on the upper side in the opening angle is disposed at a position farther from the axial center O1 than the lower second flat surface portion b2 (Z1> Z2).

[Supporting shaft engagement]
Hereinafter, the operation of engaging the support shaft 62 configured as described above with the front bearing 72 will be described with reference to FIGS. When the right door 60 is assembled to the feeding frame 32A, the right door 60 is swung along the mounting angle (70 degrees) with the support shaft 61 fitted to the back bearing 71 as described above. Thereby, as shown in FIG. 6, the support shaft 62 moves along the guide portion 72 c and reaches the opening 72 b of the front bearing 72.

  When the support shaft 62 passes through the opening 72b, the first flat surface portion b1 and the second flat surface portion b2 are in a state of facing the periphery of the opening 72b. At this time, since the support shaft 62 is formed asymmetrically with respect to the shaft center O1, the shaft center O1 passes below the center position in the vertical direction of the opening 72b.

  The support shaft 62 contacts the bearing portion 72a of the front bearing 72 after passing through the opening 72b. At this time, as shown in FIG. 7, the axial center O1 of the support shaft 62 coincides with the center position of the bearing portion 72a by bringing the first arc portion a1 of the support shaft 62 into surface contact with the bearing portion 72a. That is, the position of the shaft center O1 of the support shaft 62 held by the bearing portion 72a is offset upward as viewed from the mounting angle with respect to the position of the shaft center O1 when passing through the opening 72b. In other words, the shaft center O1 of the support shaft 62 held by the front bearing 72 is above the straight line D1 drawn along the mounting angle from the position of the shaft center O1 when passing through the opening 72b. Is displaced. As the support shaft 62 is offset in this way, a part of the second arc portion a2 of the support shaft 62 comes into contact with the bearing portion 72a, contributing to the direction in which the amount of engagement between the support shaft 62 and the bearing portion 72a is increased. To do.

  As shown in FIGS. 8 and 9A, after the right door 60 is lifted from the mounting angle (70 degrees) to the opening angle (50 degrees), the rotation guide 63 is engaged with the stopper 73, thereby The door 60 is supported by the feeding frame 32A. At this time, the contact area between the second arc portion a2 of the support shaft 62 and the bearing portion 72a is increased by 20 degrees which is the difference between the mounting angle and the opening angle, and the amount of hooking that can sufficiently hold the support shaft 62 is obtained. Secured.

  Then, as shown in FIG. 10, the right door 60 is moved from the open position to the closed position, and the hook 64 is engaged with the feeding frame 32A, whereby the assembly of the right door 60 is completed. Through the above steps, the right door 60 is assembled to the sheet feeding device 32 at the time of manufacturing or the like. When the right door 60 is removed from the feeding frame 32A, the support shaft 62 is disengaged from the front bearing 72 by following the above-described assembly operation in reverse, and then the support shaft 61 is detached from the back bearing 71. . When the right door 60 is removed, the inside of the sheet feeding device 32 can be accessed, and maintenance work and the like can be easily performed. The feeding unit 52 according to the present embodiment is screwed to the feeding frame 32A from the right side of the sheet feeding device 32, and can be easily replaced by removing the right door 60 and the outer cover 91. (See FIG. 3 (a)).

[Effect of this embodiment]
Thus, in this embodiment, the support shaft 62 is asymmetric with respect to the axial center O1, so that the position of the support shaft 62 held by the front bearing 72 passes through the opening 72b of the front bearing 72. Is offset upward with respect to the locus (D1) of the axial center O1. As a result, as shown in FIG. 9A, the amount of engagement Y between the support shaft 62 of the right door 60 in the open position and the bearing portion 72a of the front bearing 72 is symmetrical with respect to the shaft center O1. When it is formed (broken line), it becomes larger than the hanging amount y. Therefore, according to the configuration of the present embodiment, the support shaft 62 can be disengaged from the front bearing 72 even when the difference between the mounting angle and the opening angle is small (particularly when the difference is 20 degrees or less). Therefore, the right door 60 can be stably supported. However, the present technology can be applied even when the difference between the mounting angle and the opening angle is larger than 20 degrees, and even in such a case, the effect of preventing the engagement and disengagement of the support shaft 62 can be obtained.

  Further, in this embodiment, the center of gravity of the right door 60 in the open position is configured to be located outward (rightward in the drawing) from the engagement position of the stopper 73 with respect to the rotation guide 63. Accordingly, as shown in FIG. 9A, the gravity (arrow W) applied to the right door 60 becomes a force (arrow F) that urges the support shaft 62 in the upper left direction in the drawing with the stopper 73 as a fulcrum. The support shaft 62 is pressed against the wall surface of the bearing portion 72a. For this reason, the possibility that the support shaft 62 is disengaged from the front bearing 72 can be further reduced.

  Note that it is conceivable that the shape of the support shaft 62 is offset to the lower right in FIG. 9A, contrary to that described in the present embodiment. However, in such a configuration, the amount of exposure of the support shaft 62 in the opening 72b when the right door 60 is in the open position is increased by offsetting the shaft shape. That is, when the support shaft 62 is engaged with the front bearing 72, the portion that is in contact with the bearing portion 72a due to the offset shape passes through the opening 72b when the right door 60 is lifted from the mounting angle to the opening angle. Does not work in the direction of increasing the amount of hook. On the other hand, by setting the direction as in this embodiment, it is possible to create a state in which the support shaft 62 and the front bearing 72 are stably engaged.

  By the way, in the present embodiment, the bearing portion 72a which is the inner peripheral portion has been described as being formed in an arc shape (C shape), but if the bearing portion 72a is formed along an inscribed circle. For example, the bearing portion 72a may have a polygonal shape. In other words, the inner peripheral portion is in contact with the outer peripheral portion of the support shaft 62 at the contact points arranged on the same circumference, and the support shaft 62 holds the support shaft 62 so that the support shaft 62 can rotate and cannot move in the radial direction. What is necessary is just to hold | maintain the outer peripheral part. Similarly, the outer periphery of the support shaft 62 may have a polygonal shape, for example, as long as it is slidably contacted with the inner peripheral portion of the engaging portion and held rotatably.

  Next, the assembly structure of the hinge mechanism according to the second embodiment will be described. This embodiment is different from the first embodiment in that the position of the opening is offset instead of the shape of the support shaft. Since the other configuration is the same as that of the first embodiment, common elements are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 11A, the hinge mechanism according to the present embodiment includes a support shaft 68 provided on the front side of the right door 60, and a front bearing 78 as an engaging portion with which the support shaft 68 engages. Is included. The front bearing 78 extends along a mounting angle (70 degrees) from the arc-shaped bearing portion 78a that is an inner peripheral portion, an opening portion 78b that opens radially outward from the bearing portion 78a, and the opening portion 78b. And a guide portion 78c to be taken out.

  As shown in FIG. 11B, the support shaft 68 includes a first arc portion a1 and a second arc portion a2 that are arc-shaped, and a first plane portion b1 and a second plane portion b2 that are formed in parallel to each other. And have. However, unlike the first embodiment, the first plane part b1 and the second plane part b2 are arranged at the same distance Z3 from the axis center O2, and the support shaft 68 is formed symmetrically with respect to the axis center O2.

  Here, as shown in FIG. 11A, the opening 78b of the front bearing 78 is offset downward with respect to the center position of the bearing 78a as viewed from the mounting angle (position of the shaft center O2 of the support shaft 62). Are arranged to be. That is, for the upper end 78d and the lower end 78e that form the opening 78b as both ends of the bearing 78a, the upper end with respect to the straight line D2 drawn along the mounting angle from the center position of the bearing 78a. The portion 78d is provided at a position closer to the lower end portion 78e. The guide portion 78c extends from the lower end portion 78e along the mounting angle.

  In the hinge mechanism configured as described above, the support shaft 68 engages and disengages from the front bearing 78 by the same operation as in the first embodiment. That is, by swinging the right door 60 along the mounting angle, the support shaft 68 is moved along the guide portion 78c and engaged with the bearing portion 78a through the opening 78b. At this time, because the position of the opening 78b is offset, the shaft center O2 of the support shaft 68 moves upward as viewed from the mounting angle when engaging the bearing 78a. Then, with the right door 60 raised to the opening angle, the rotation guide 63 is engaged with the stopper 73 so that the right door 60 can be opened and closed.

  Thus, in this embodiment, the opening 78b is offset with respect to the center position of the bearing portion 78a. With this configuration, when the position of the shaft center O2 of the support shaft 68 held by the bearing portion 78a passes through the opening 78b of the front bearing 78 as viewed from the mounting angle, as in the first embodiment. Is offset upward with respect to the position of the axial center O2. Therefore, according to the configuration of the present embodiment, the amount of engagement between the support shaft 68 and the bearing portion 78a when the right door 60 is in the open position is larger than when the opening portion 78b is arranged without being offset. can do. Even when the difference between the mounting angle and the opening angle is small, the possibility that the support shaft 68 is disengaged from the front bearing 78 when the right door 60 is opened and closed can be reduced.

[Other Embodiments]
In Embodiment 1 described above, the support shaft 62 has been described as having an offset two-sided (I-cut) shape, but the support shaft may have a so-called D-cut shape. That is, as shown in FIG. 12, a support shaft 69 having a cylindrical outer peripheral surface 69a (a circumscribed portion) and a flat cut-out surface 69a (small diameter portion) obtained by cutting a part of the cylindrical surface is used. Can do. In this case, when the right door 60 is moved along the mounting angle, the same effect as in the first embodiment can be obtained by disposing the notch surface 69a on the lower side.

  The configuration in which the shape of the support shaft is offset as in the first embodiment and the configuration in which the position of the opening 78b of the front bearing 78 is offset as in the second embodiment can be used in combination.

  In the first and second embodiments, the right door 60 is lifted upward when moving from the mounting angle to the opening angle. In accordance with this, the position of the shaft center of the support shafts 62 and 68 held by the bearing portions 72a and 78a is offset upward with respect to the position of the shaft center when passing through the openings 72b and 78b. did. However, when the opening / closing direction of the right door 60 is different (for example, when the support shaft is provided above the opening / closing member), it is preferable to set the offset direction accordingly.

  In the first and second embodiments, the right door 60 provided in the option feeder has been described as an example of the opening and closing member. However, the present technology is a cover member that can be opened and closed with respect to the apparatus main body 1A of the image forming apparatus 1. It may be applied as a support structure. The open / close member is not limited to one that is opened and closed to open the sheet conveyance path, and the present technology may be applied as a support structure of a support member that supports a sheet, such as a manual feed tray.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus / 1A ... Apparatus main body / 31, 32, 33, 34 ... Sheet feeding apparatus / 32 ... Main body (feeding frame) / 52 ... Feeding means (feeding unit) / 60 ... Opening / closing member (right) Door) / 62,68 ... support shaft / 72,78 ... engaging part / 72a, 78a ... inner peripheral part (bearing part) / 72b, 78b ... opening part / 72c, 78c ... guide part / a1, a2 ... external part (First arc portion, second arc portion) / b1, b2... Small diameter portion (first plane portion, second plane portion)
O1, O2 ... axis of support shaft

Claims (13)

A support structure for the opening / closing member that supports the opening / closing member to be openable / closable with respect to the body,
Restricting means for restricting the opening / closing member from rotating beyond a predetermined opening angle with reference to the closed state of the opening / closing member;
An engaging portion provided on one of the main body and the opening and closing member;
A support shaft that is provided on the other of the main body and the opening / closing member and is detachably engaged with the engaging portion by swinging the opening / closing member along a mounting angle larger than the opening angle. Prepared,
The engaging portion includes an inner peripheral portion formed along an inscribed circle, and an opening portion that opens radially outward from the inner peripheral portion with a width smaller than the diameter of the inscribed circle. Have
The support shaft has an outer diameter that is larger than the width of the opening and is in sliding contact with the inner peripheral portion, and a small diameter portion that is formed to be equal to or smaller than the width of the opening as viewed from the mounting angle. Have
The position of the shaft center of the support shaft in a state where the circumscribed portion is held on the inner peripheral portion with respect to the position of the shaft center when passing through the opening, as viewed from the mounting angle, Forming the engagement portion and the support shaft so as to be offset in a direction in which the opening / closing member is moved from the mounting angle toward the opening angle;
A support structure for an opening / closing member. The engaging portion is disposed on the main body;
The support shaft is disposed on the opening / closing member,
The opening / closing member support structure according to claim 1. A guide portion that extends from the opening portion along the mounting angle and contacts the small diameter portion to guide the support shaft to the engagement portion is provided.
The support structure for the opening and closing member according to claim 2. The support shaft is formed asymmetric with respect to the axis center,
The support structure for the opening and closing member according to claim 2 or 3. The small-diameter portion includes a first plane portion and a second plane portion that are formed in parallel with each other across the axis center,
The distance from the axis center to the first plane part is different from the distance from the axis center to the second plane part,
The support structure of the opening / closing member according to claim 4. The circumscribed portion is formed in an arc shape centered on the axis center;
The small diameter portion is formed in a planar shape connecting one end and the other end of the circumscribed portion,
The support structure of the opening / closing member according to claim 4. The opening of the engaging portion is offset with respect to the center position of the inner peripheral portion viewed from the mounting angle.
The opening / closing member support structure according to any one of claims 2 to 6. The opening / closing member rotates around a lower portion closed with respect to the main body,
The position of the shaft center of the support shaft in a state where the circumscribed portion is held on the inner peripheral portion is offset upward as viewed from the mounting angle with respect to the position of the shaft center when passing through the opening. It is characterized by
The opening / closing member support structure according to any one of claims 1 to 7. The restricting means includes a locking portion fixed to the main body, and a locked portion provided on the opening / closing member and locked by the locking portion,
When the opening / closing member is at the opening angle, the center of gravity of the opening / closing member is located outward from the engagement position between the locking portion and the locked portion.
The support structure for the opening and closing member according to claim 8. The difference between the mounting angle and the opening angle is 20 degrees or less,
The opening / closing member support structure according to any one of claims 1 to 9. A bearing portion provided on the one of the main body and the opening / closing member;
A shaft that is provided on the opposite side of the support shaft with respect to the other of the main body and the opening / closing member, and that is rotatably supported by the bearing portion,
The support shaft engages with the engaging portion by swinging the opening / closing member along the mounting angle while the shaft is held by the bearing portion.
The support structure of the opening-closing member described in any one of Claims 1 thru | or 10. A main body provided with a feeding means for feeding the sheet;
An opening and closing member that can be opened and closed with respect to the main body;
The support structure for the opening and closing member according to any one of claims 1 to 11, wherein the opening and closing member is supported by the body.
A sheet feeding apparatus having An apparatus main body provided with image forming means for forming an image;
An opening and closing member that can be opened and closed with respect to the apparatus body;
The support structure for the opening and closing member according to any one of claims 1 to 11, wherein the opening and closing member is supported by the apparatus main body.
An image forming apparatus.

Images