JP2015004904A - Paper guide device and fixing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate the adjustment of the fixing position of a paper guide mainly in a paper thickness direction.SOLUTION: A paper guide device includes a frame 11 and a paper guide 20. The frame 11 includes a support part 111 formed with a screw hole 30. A stepped screw 50 is screwed into the screw hole 30. The sheet guide 20 includes a guide part 21 and a mounting part 22. The guide part 21 specifies the conveyance position of paper mainly in a paper thickness direction Z. The mounting part 22 is formed with a plurality of hole parts 40A to 40C along a sheet width direction Y. The positions of the plurality of hole parts 40A to 40C mainly in the paper thickness direction Z are different from each other, and the stepped screw 50 is fitted into any of those hole parts. The fixing position of the paper guide 20 with respect to the support part 111 mainly in the paper thickness direction Z is varied according to which of the plurality of hole parts 40A to 40C is subjected to the fitting of the stepped screw.

Description

  The present invention relates to a sheet guide device that guides a sheet to a predetermined transport position, and a fixing device including the sheet guide device.

  An image forming apparatus such as a copying machine or a printer that forms an image on a sheet by electrophotographic image forming processing includes a fixing device that fixes the toner image on the sheet. The fixing device includes a heating roller and a pressure roller that form a nip portion by pressing the peripheral surfaces of each other, and conveys the sheet in a direction that passes through the nip portion. While the sheet passes through the nip portion, the sheet is heated and pressurized to melt the toner image transferred on the surface of the sheet and securely fix it on the surface of the sheet.

  In order to reliably fix the toner image on the surface of the paper, it is necessary to smoothly pass the paper through the nip portion. For this reason, the fixing device includes a paper guide for guiding the paper to the nip portion (see, for example, Patent Document 1).

  In order to prevent damage and wear of the heating roller and pressure roller, the paper guide cannot be brought into contact with the peripheral surface of the heating roller and pressure roller, and the tip of the paper guide needs to be arranged at a position away from the nip portion. There is. The leading edge of the sheet that has passed through the sheet guide is displaced by its own weight until reaching the nip portion. The amount of displacement of the leading edge of the paper varies depending on the thickness of the paper, and the proper position with respect to the nip portion of the paper guide in the thickness direction of the paper also varies depending on the thickness of the paper.

  A stiff sheet such as thick paper is hardly displaced after passing through the sheet guide, and the leading edge of the sheet guide contacts the sheet so that the image on the first side does not deteriorate when forming an image on the second side of the sheet. In order to avoid this, the paper guide should be arranged at a position away from the nip portion. On the other hand, when the rigidity is weak like thin paper, the leading edge is easily displaced downward by the action of gravity, and in order to reliably guide the leading edge of the paper to the nip portion, the paper guide should be arranged at a position close to the nip portion. It is.

  Therefore, in the conventional fixing device, a long hole whose longitudinal direction is parallel to the paper thickness direction is provided in the paper guide, and the position of the fixing screw in the longitudinal direction of the long hole is changed, so that the paper guide in the paper thickness direction is changed. The fixed position is adjusted. The fixing position of the paper guide in the paper thickness direction is adjusted with an accuracy of about ± 0.5 mm according to the usage frequency of the thick paper and the thin paper during assembling work or maintenance.

JP 2013-109045 A

  However, in the conventional fixing device, when adjusting the fixing position of the paper guide in the thickness direction of the paper, the paper guide is easy to move when the operator tightens the fixing screw while pressing the paper guide with the hand. There is a problem that it is difficult to reliably fix at a desired fixing position with high accuracy. Such a problem generally occurs not only in the fixing device but also in a paper guide that defines a transport position in the thickness direction of a paper in a paper transport device.

  An object of the present invention is to provide a paper guide device that can easily adjust the fixing position of the paper guide in the paper thickness direction, and a fixing device including the paper guide device.

  The paper guide device of the present invention includes a frame and a paper guide. The frame includes a support portion that is a support portion that extends along the paper width direction orthogonal to the paper transport direction within the paper surface, and has a fixing hole to which a fixing member is coupled. The paper guide includes a guide portion and an attachment portion. The guide part mainly defines the paper transport position in the paper thickness direction. The attachment portion is formed with a plurality of hole portions, which are different from each other in the sheet thickness direction, and the fixing member is fitted along the sheet width direction.

  The paper guide is fixed to the support portion of the frame by selectively fitting the fixing member into any of the plurality of holes provided in the attachment portion of the paper guide. The fixing position of the paper guide with respect to the support portion of the frame mainly in the paper thickness direction changes depending on which of the plurality of holes is fitted with the fixing member.

  In this configuration, the support portion of the frame is a plurality of fixing holes to which the fixing member is coupled, and the same number of fixing holes as the plurality of hole portions of the attachment portion of the paper guide are arranged in the paper thickness direction along the paper width direction. Are preferably formed at the same position as the plurality of holes of the paper guide.

  The fixing position of the paper guide with respect to the frame support in the paper width direction does not change when the fixing member is fitted in any of the plurality of holes of the paper guide, preventing the device from becoming large in the paper width direction. it can.

  Further, the mounting portion of the paper guide may be formed with a plurality of sets of holes along the paper width direction, and the support portion of the frame may be formed with at least a set number of screw holes.

  By fitting the fixing member into any of the plurality of holes for each group, the paper guide can be fixed to the support portion of the frame in a stable state.

  Further, with respect to the sheet thickness direction, the mounting portion of the sheet guide is such that each of the plurality of holes is formed at the same position for each set, and the support portion of the guide frame has all the fixed holes for the number of sets. It may be formed at the same position.

  By fitting a fixing member into a hole having the same position in the paper width direction in each group, the paper guide is fixed in parallel to the paper width direction, and the adjustment work of the fixing position of the paper guide can be simplified. .

  In this case, the adjustment work of the fixing position of the paper guide can be further simplified by writing the same index in the hole portion where the paper width position in each group is the same.

  According to the present invention, it is possible to easily adjust the fixing position of the paper guide mainly in the paper thickness direction.

1 is a schematic view of an image forming apparatus including a fixing device according to an embodiment of the present invention. 2 is a schematic view of the fixing device. FIG. It is a figure which shows the paper guide apparatus which concerns on 1st Embodiment of this invention. It is a figure which shows the paper guide apparatus which concerns on 2nd Embodiment of this invention. It is a figure which shows the paper guide apparatus which concerns on 3rd Embodiment of this invention. It is a figure which shows the paper guide of the paper guide apparatus which concerns on 4th Embodiment of this invention. It is a figure which shows the flame | frame of the paper guide apparatus which concerns on 4th Embodiment of this invention. It is a figure which shows the paper guide of the paper guide apparatus which concerns on 5th Embodiment of this invention.

  Hereinafter, a fixing device to which a paper guide device according to an embodiment of the present invention is applied will be described with reference to the drawings. As shown in FIG. 1, the image forming apparatus 100 includes an image reading unit 110, an image forming unit 120, a paper feeding unit 130, and a paper transporting unit 140, and performs electrophotographic image forming processing on paper. The paper includes not only plain paper but also recording media such as photographic paper and OHP film as well as thick paper and thin paper.

  The image reading unit 110 outputs image data read from the document to the image forming unit 120. The sheet feeding unit 130 stores a plurality of sheets and feeds them one by one to the sheet conveying unit 140. The paper transport unit 140 includes a main transport path 141 and a sub transport path 142 that are formed from the paper feed unit 130 through the image forming unit 120 to the paper discharge unit 150.

  The image forming unit 120 is configured to transfer a single-color or multi-color toner image formed based on the image data input from the image reading unit 110 by an electrophotographic image forming process, Transfer on both sides. The image forming unit 120 includes the fixing device 10. The fixing device 10 fixes the toner image on the surface of the paper.

  When images are formed on both sides of a sheet, the sheet that has been fed from the sheet feeding unit 110 and passed through the fixing device 10 is switched back on the downstream side of the fixing device 10 in the main conveyance path 141, and the sub conveyance path 142 is led to the upstream side of the image forming unit 120 in the main transport path 141. While the sheet passes through the image forming unit 120 twice, a toner image is formed on each of the first surface and the second surface.

  As shown in FIG. 2, the fixing device 10 includes a heating roller 12 and a pressure roller 13 in a frame 11 so as to be rotatable. The heating roller 12 and the pressure roller 13 constitute a nip portion 14 by pressing a part of their peripheral surfaces. The nip portion 14 corresponds to the fixing position of the present invention. The sheet on which the toner image is transferred is heated and pressurized while passing through the nip portion 14, and the toner image is melted and fixed on the surface of the sheet.

  The frame 11 includes a support portion 111 on one surface. The paper guide 20 is fixed to the support portion 111. The paper guide 20 is formed by pressing a metal flat plate as an example, and includes a guide portion 21 and an attachment portion 22. The guide portion 21 and the attachment portion 22 are continuous with the bent portion 23 interposed therebetween. The frame 11 and the paper guide 20 constitute the paper guide device of the present invention.

  The paper guide 20 is disposed so that the tip 211 of the guide portion 21 is close to the nip portion 14. The guide unit 20 guides the leading end of the sheet 200 that has been conveyed in the direction of the arrow X in the main conveyance path 141 to the nip unit 14.

  When the rigidity of the paper sheet 200 is sufficiently strong, the leading edge of the paper sheet 200 is hardly displaced in the thickness direction of the paper sheet 200 (hereinafter referred to as “paper thickness direction Z”) indicated by an arrow Z in the figure, and is formed by the guide unit 21. It is conveyed into the nip portion 14 without requiring guidance. For the stiff paper 200, the tip 211 of the guide portion 21 is indicated by a broken line in FIG. 2 in order to prevent deterioration of the image on the first surface when forming the image on the second surface when images are formed on both sides. In addition, it is preferable that the sheet thickness direction Z is retracted from the nip portion 14 and is not brought into contact with the sheet 200.

  On the other hand, when the rigidity of the paper 200 is weak, the leading edge of the paper 200 is likely to be displaced in the paper thickness direction Z, and there is a high possibility that the paper 200 cannot be conveyed into the nip part 14 without guidance by the guide part 21. For the paper 200 having low rigidity, in order to fix the toner image accurately, the tip 211 of the guide portion 21 is overlapped with the nip portion 14 in the paper thickness direction Z as shown by a two-dot chain line in FIG. It is necessary to make it contact 200 well.

  As described above, the appropriate position of the guide portion 21 in the sheet thickness direction Z varies depending on the rigidity of the sheet 200 to be conveyed. The paper guide 20 can be selectively fixed to any one of a plurality of positions in the paper thickness direction Z in the support portion 111 of the frame 11.

  As shown in FIG. 3, in the paper guide device according to the first embodiment of the present invention, screw holes 30 are formed in the support portion 111 of the frame 11, and three holes 40 </ b> A to 40 </ b> C are formed in the attachment portion 22 of the paper guide 20. Is forming. The screw hole 30 corresponds to a fixing hole of the present invention, and a stepped screw 50 that is a fixing member of the present invention is coupled by screwing of a screw portion. The holes 40 </ b> A to 40 </ b> C are formed at equal intervals along the paper width direction Y orthogonal to the paper transport direction X within the paper surface, mainly at different positions in the paper thickness direction Z. The inner diameters of the hole portions 40A to 40C are equal to the outer diameter of the cylindrical portion of the stepped screw 50.

  The paper guide 20 is fixed to the frame 11 by fitting the stepped screw 50 into any of the holes 40 </ b> A to 40 </ b> C and then screwing it into the screw hole 30. The fixing position of the paper guide 20 with respect to the frame 11 in the paper thickness direction Z changes depending on which of the hole portions 40A to 40C is fitted to the stepped screw 50, and the nip portion 14 at the tip 211 of the guide portion 21 is changed. The position in the sheet thickness direction Z with respect to the position changes.

  By screwing the stepped screw 50 into the screw hole 30 in a state where the stepped screw 50 is fitted in any of the holes 40A to 40C, the position in the sheet thickness direction Z with respect to the nip portion 14 at the tip 211 of the guide portion 21 is changed to the sheet. Can be easily fixed at an appropriate position according to the deformation state.

  For example, of the holes 40A to 40C, a hole that matches the rigidity of the frequently used paper in the image forming apparatus 100 is positioned concentrically with the screw hole 30, and the stepped screw 50 is inserted into the holes 40A to 40C. After passing through any of them, the screw hole 30 is rotated in the fastening direction.

  The leading edge of the sheet onto which the toner image has been transferred by the sheet guide 20 can be reliably guided to the nip portion 14 between the heating roller 11 and the pressure roller 12 of the fixing device 10, and the toner image is reliably fixed on the sheet surface. Can be made.

  As shown in FIG. 4, the paper guide device according to the second embodiment of the present invention is such that screw holes 30 </ b> A to 30 </ b> C having the same number as the holes 40 </ b> A to 40 </ b> C are formed in the support portion 111 of the frame 11. Each of the screw holes 30 </ b> A to 30 </ b> C is formed at the same position as each of the hole portions 40 </ b> A to 40 </ b> C in the paper width direction Y and mainly at the same position in the paper thickness direction Z.

  When the paper guide 20 is disposed at an appropriate position with respect to the frame 11 in the paper width direction Y, the positions of the holes 40A to 40C coincide with the positions of the screw holes 30A to 30C.

  Since the position of the paper guide 20 in the paper width direction Y is not displaced when the stepped screw 50 is fitted in any of the holes 40A to 40C, the paper guide device does not increase in size in the paper width direction Y.

  As shown in FIG. 5, in the paper guide device according to the third embodiment of the present invention, two sets of holes 40 </ b> A to 40 </ b> C are formed in the attachment portion 22 of the paper guide 20, and two sets are formed in the support portion 111 of the frame 11. Screw holes 30A to 30C are formed.

  By fitting and screwing the stepped screw 50 into any one of the holes 40A to 40C of each group and any one of the screw holes 30A to 30C corresponding thereto, mainly in the sheet thickness direction Z. The position of the sheet guide 20 can be made constant over the entire area in the sheet width direction Y.

  As shown in FIGS. 6 and 7, in the paper guide device according to the fourth embodiment of the present invention, two sets of holes 40 </ b> A to 40 </ b> E and 41 </ b> A to 41 </ b> E are formed in the attachment portion 22 of the paper guide 20. Two sets of screw holes 30 </ b> A to 30 </ b> E are formed in the support portion 111.

  Each of the holes 40 </ b> A to 40 </ b> E is disposed at a position different from each other mainly in the sheet thickness direction Z. Each of the holes 41A to 41E is arranged at the same position as each of the holes 40A to 40E mainly in the sheet thickness direction Z.

  Each of the screw holes 30A to 30E in each group is formed at the same position as each of the hole portions 40A to 40E and the hole portions 41A to 41E in the paper width direction Y and mainly at the same position in the paper thickness direction Z. Has been. The hole portions 40A to 40E have a circular shape, and the hole portions 41A to 41E have an oval shape whose longitudinal direction matches the paper width direction Y. Each of the holes 41A to 41E is an oval having a shape in which a circle having the same diameter as the holes 40A to 40E is extended in the paper width direction Y.

  A plurality of ribs 212 are formed in the guide portion 21 of the paper guide 20 along the paper width direction Y. The plurality of ribs 212 reduce the contact area of the paper with the guide portion 21 and reduce the resistance acting on the paper from the guide portion 21.

  When the paper guide 20 is disposed at an appropriate position with respect to the frame 11 in the paper width direction Y, the positions of the hole portions 40A to 40E and the hole portions 41A to 41E are the positions of the screw holes 30A to 30E of the respective groups. Matches.

  By fitting and screwing the stepped screw 50 into any one of the corresponding screw holes 30A to 30C, the position of the paper guide 20 in the paper thickness direction Z is made constant over the entire region in the paper width direction Y. Can do.

  Since the holes 41 </ b> A to 41 </ b> E are formed in an oval shape, the dimensional errors of the positions of the holes in the paper guide 20, the frame 11, and the attachment part 22 in the paper width direction Y and the positions of the screw holes in the support part 111. Can absorb.

  In addition, a locking hole 42 is formed in the attachment portion 22, and a protrusion 32 is formed in the support portion 111. The protrusion 32 protrudes in the mounting direction of the mounting portion 22 with respect to the support portion 111.

  Prior to fastening the stepped screw 50, the paper guide 20 is temporarily fixed to the frame 11 by inserting the protrusion 32 into the locking hole 42. The operator does not need to hold the paper guide 20 until the paper guide 20 is fixed to the frame 11, and the workability is improved.

  As shown in FIG. 8, the paper guide device according to the fifth embodiment of the present invention is a paper guide 20 of the paper guide device according to the fourth embodiment, in which indices 43 </ b> A to 43 </ b> E are further described on the attachment portion 22. is there. The indicators 43A to 43E are characters as an example, and specify each hole in each of the two sets of holes 40A to 40E and holes 41A to 41E. The indicators 43A to 43E are the two sets of the hole portions 40A to 40E and the hole portions 41A to 41E, respectively, and the same characters are given to the holes whose positions in the sheet thickness direction Z are mainly the same.

  In each of the two sets of hole portions 40A to 40E and hole portions 41A to 41E, the stepped screw 50 is fitted into the hole portion having the same index, so that the sheet guide 20 in the sheet thickness direction Z is fitted. The position can be constant over the entire area in the sheet width direction Y. Even when the number of holes constituting each group is increased, the hole to which the stepped screw 50 is to be fitted can be easily specified in each group, and workability is improved.

  The fixing hole and the fixing member of the present invention are not limited to the screw hole 30 and the stepped screw 50, respectively, and arbitrary parts such as a socket hole and a plug are used on the condition that they can be separated from each other. Can do.

  The paper guide device according to the present invention can be generally applied not only to a fixing device of an image forming apparatus but also to a device that transports paper such as a paper folding device, a punching device, and a bookbinding device.

DESCRIPTION OF SYMBOLS 10 Fixing device 11 Frame 12 Heating roller 13 Pressure roller 14 Nip part 20 Paper guide 21 Guide part 22 Mounting part 30 Screw hole (fixing hole)
30A-30E Screw hole (fixing hole)
40A-40E Hole 50 Stepped Screw (Fixing Member)
100 Image forming apparatus 200 Paper

Claims (5)

A paper guide device that defines a transport position in a paper thickness direction of a paper transported along a paper transport direction,
A frame having a support portion along a paper width direction orthogonal to the paper conveyance direction in the paper surface;
A guide portion that opposes the paper in the entire region in the paper width direction, and a paper guide that includes an attachment portion that is continuous with the guide portion in the paper thickness direction;
A fixing member for fixing the paper guide to the frame;
With
The support part is formed with a fixing hole in which the fixing member is separable and coupled,
A paper guide device in which the attachment portion is a plurality of hole portions whose positions in the paper thickness direction are different from each other, and a plurality of hole portions into which the fixing member is fitted are formed along the paper width direction. .   The support portion is a plurality of fixing holes to which the fixing member is selectively coupled, and the same number of fixing holes as the plurality of hole portions are mainly at the same position in the paper thickness direction, and the paper width direction. The paper guide device according to claim 1, wherein the paper guide device is formed at the same interval as the plurality of holes along the line. The mounting portion is formed with a plurality of sets of the plurality of hole portions along the paper width direction,
The sheet guide device according to claim 1, wherein the support portion has at least as many fixing holes as the plurality of sets. Each of the plurality of holes in each of the plurality of sets is formed at the same position mainly in the sheet thickness direction.
4. The paper guide device according to claim 3, wherein all of the fixing holes corresponding to the number of the plurality of sets are formed at the same position mainly in the paper thickness direction. A fixing device that is applied to an image forming apparatus that performs electrophotographic image formation and fixes a toner image onto a sheet at a predetermined fixing position,
A fixing device comprising the paper guide device according to claim 1 on an upstream side of the fixing position in a paper transport direction.

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