JP2008273648A - Paper guide mechanism, paper carrying mechanism and image forming device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detachably hold a roller while securing sufficient strength. <P>SOLUTION: This paper guide mechanism has a roller part 20 having a roller shaft 221, a roller 222 rotatably installed on the roller shaft and a bearing member 21 having a through-hole 21b for penetrating the roller shaft, a body part 10 holding the roller part, and an energizing spring 230 applying energizing force to the roller shaft, and is formed so that the body part 10 includes slits 221b and 221e for arranging the roller shaft on its inside, and has a guide part 210 having a guide surface for guiding paper carried by the roller part, and the energizing spring applies the energizing force in the direction toward the opening end of the slits, and the roller part and the body part are connected via the bearing member, and the bearing member is insertably-extractably installed in the body part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sheet guide mechanism used in an image forming apparatus such as a copying machine, a printer, and a FAX, and an image forming apparatus using the same.

  2. Description of the Related Art Conventionally, an image forming apparatus such as a copying machine or a printer has a built-in paper transport mechanism for transporting paper before or after image formation as necessary. FIG. 9 is a schematic configuration diagram of an example of such a paper transport mechanism.

  As shown in FIG. 9, the paper transport mechanism 100 includes a driving roller 111 and a driven roller 121 that faces the driving roller 111 and contacts with a predetermined nip length.

  The driving roller 111 is provided on the housing 110 side of the image forming apparatus, and is rotated by driving means such as a stepping motor (not shown). The driven roller 121 is provided on a paper guide mechanism 120 that constitutes a part of the wall surface of the housing 110, and follows the rotation of the driving roller 111.

  Further, the housing 110 of the image forming apparatus is provided with a guide wall 113 and a ceiling portion 114, which together with the guide member 122 provided in the paper guide mechanism 120 conveys the paper conveyed from the conveyance roller 112. The direction is defined, and the sheet is conveyed along a conveyance path A indicated by a broken line arrow in the drawing.

  As an example, such a paper transport mechanism 100 is used for passing a paper on which a toner image after passing through a fixing device (not shown) is fixed and transporting the paper to the outside of the image forming apparatus.

  Further, as shown in FIG. 10, the paper transport mechanism 100 has a configuration in which the paper guide mechanism 120 opens and closes with the rotation shaft 130 as a fulcrum. As a result, the inside of the housing 110 can be exposed to the outside by an operation from the outside, and when a paper jam occurs in the transport path A during paper transport, the user selects the jammed paper as indicated by a broken line arrow B in the figure. It can be removed from the direction of the outside.

  With this configuration, the paper transport mechanism including the paper guide mechanism 120 can cope with abnormal paper transport in the image forming apparatus.

  Next, FIG. 11 is a main part configuration diagram of the paper guide mechanism 120. As shown in FIG. 11, the sheet guide mechanism 120 traverses a plurality of guide plates 210 and a plurality of guide plates 210 that are disposed at a predetermined interval on the main body 200 and constitute the guide member 122 of FIG. 9. A pair of roller portions 220 and a biasing spring 230 are provided. The main body 200 and the guide plate 210 are integrally formed using a resin such as PET.

  The roller unit 220 includes a roller shaft 221 and rollers 222 provided at both ends of the roller shaft 221, and the rollers 222 are configured to freely rotate with respect to the roller shaft 221. Further, the biasing spring 230 is disposed between the roller shaft 211 and the main body portion 200, and the roller portion 220 is brought into contact with the driving roller 111 of FIG. 9 by contacting the roller shaft 221. Give power.

  Next, FIG. 12 is an enlarged view of the main part C of FIG. 11, FIG. 13 (a) is a cross-sectional view taken along the line AA 'of FIG. 12, and FIG. 13 (b) is a cross-sectional view taken along the line BB' of FIG. Yes (see, for example, Patent Document 1).

  As shown in FIGS. 12 and 13, the guide plate 210 does not have a guide plate 210a and a guide plate 210b through which the roller shaft 211 passes through the slit, a guide plate 210c through which the roller 222 passes through the slit, and a slit. The guide plate 210d is composed of four types of guide plates.

  As shown in FIG. 13A, the guide plate 210 a is provided with a slit 211 a that increases in width as it approaches the main body 200. The slit 211 a has a shape in which the edge 2112 of the opening further wraps inward, so that the width is narrower than the outer diameter of the roller shaft 221. As shown in FIG. 12, the roller shaft 221 is lifted in the direction of the arrow by the biasing spring 230, but the lifted roller shaft 221 is moved outward from the slit 211 a by the edge 212 of the slit 211 a of the guide plate 210. By restricting the movement to come out, the main body 200 is not detached.

  Further, since the guide plate 210a is made of resin, the roller shaft 221 can be detached from the slit 211a by applying a certain force. As a result, the roller section 220 is detachable from the main body section 200, and maintenance of the sheet guide mechanism 120 can be performed in a state of being incorporated in the image forming apparatus as shown in FIG.

Next, as shown in FIG. 13B, the guide plate 210 b is provided with slits 211 b that are wider than the outer diameter of the roller shaft 221 and have an equal interval. As a result, the roller shaft 221 is kept in a non-contact state with the slit 211b. The guide plate 210b has a configuration with slits similar to the guide plate 210b except that the width is larger than the outer diameter of the roller 222, and is not in contact with the roller 222 as in the case of the guide plate 210b. Keep the state of.
JP 2006-335501 A

  However, the conventional paper guide mechanism 120 has the following problems.

  As described with reference to FIG. 13A, in the configuration of the paper guide mechanism 120, the roller shaft 221 can be rotated by being pressed against the edge 212 of the opening of the slit 211a of the guide plate 210a. This means that the roller shaft 221 is substantially held by the guide plate 210a.

  The guide plate 210a is integrally formed with the main body 200. However, as described above, when the paper transport mechanism is provided downstream of the fixing device, the guide plates 210a to 210d as the guide member 122 are separated from the fixing device. Heat transfer from the paper carrying the heat of fixing and heat at the time of fixing. Therefore, for the molding of the main body 200, a heat-resistant PET resin or the like is used, but such a resin has a low elasticity and is fragile.

  Particularly, since the paper guide mechanism 120 has a structure that can be opened and closed as a hatch of the image forming apparatus as shown in FIGS. 9 and 10, the edge 212 of the slit 211a is elastic from the biasing spring 230 every time it is opened and closed. A physical load such as a change in force and a collision of the roller shaft 221 is received. Furthermore, even when the attachment / detachment of the roller part 220 from the main body part 200 is repeated for maintenance, a physical load is applied to the slit 211a and the edge part 212.

  Therefore, in the conventional paper guide mechanism 120 that holds the roller shaft 221 using the guide plate 210a, there is a possibility that the holding of the roller shaft 221 cannot be secured due to wear and deformation of the edge portion 212 of the slit 211a.

  As described above, in the conventional paper guide mechanism, there is a possibility that the structure for holding the roller cannot secure sufficient strength during maintenance or long-term use, and as a result, there is a risk of causing a failure in the paper transport operation. It was.

  The present invention has been made in view of such problems, and the present invention provides a paper guide mechanism capable of detachably holding a roller while ensuring sufficient strength, a paper transport mechanism using the paper guide mechanism, and an image. An object is to provide a forming apparatus.

In order to achieve the above object, a first aspect of the present invention is a roller unit including a roller shaft, a roller rotatably attached to the roller shaft, and a bearing member having a through hole through which the roller shaft passes. ,
A main body portion for holding the roller portion;
An urging portion for applying an urging force to the roller shaft,
The main body is
The roller shaft includes a slit disposed therein, and has a guide portion having a guide surface for guiding paper conveyed by the roller portion;
The biasing portion applies the biasing force in a direction toward the opening end of the slit;
The roller part and the main body part are connected via the bearing member,
The bearing member is a paper guide mechanism that is detachably attached to the main body.

In the second aspect of the present invention, the guide portion has a plurality of guide plates arranged in parallel so that the slits face each other.
The bearing member is the sheet guide mechanism according to the first aspect of the present invention, which is a plate-like member that comes into contact with at least one of the plurality of guide plates.

Further, according to a third aspect of the present invention, the guide portion has a facing surface facing the guide plate that comes into contact with the bearing member,
The bearing member is disposed between the guide plate and the facing surface,
The bearing member is the paper guide mechanism according to the second aspect of the present invention, having a contact portion that contacts the facing surface.

  The fourth aspect of the present invention is the paper guide mechanism according to the third aspect of the present invention, wherein the contact portion is in contact with the opposing surface with a certain elastic force.

  The fifth aspect of the present invention is the paper guide mechanism according to the third or fourth aspect of the present invention, wherein the contact portion has a contact surface that contacts the facing surface.

Further, in the sixth aspect of the present invention, the bearing member is fixed to the main body portion with a force that resists at least the urging force,
The through hole of the bearing member has a gap in which the roller shaft can move along the direction of the biasing force,
The urging portion is disposed between the roller shaft and the main body portion,
It is a paper guide mechanism according to any one of the first to fifth aspects of the present invention.

Further, according to a seventh aspect of the present invention, the bearing member is mounted on the main body portion with a margin capable of moving along the direction of the biasing force.
The through hole of the bearing member has a gap in which the roller shaft can rotate,
The urging portion is provided on the bearing member,
It is a paper guide mechanism according to any one of the first to fifth aspects of the present invention.

The eighth aspect of the present invention includes a drive roller,
A driven roller that is driven in contact with the drive roller;
A guide portion for guiding paper to a contact portion between the drive roller and the driven roller;
The paper guide mechanism according to any one of the first to seventh aspects of the present invention is used as the guide part,
It is a paper transport mechanism having the roller of the roller portion of the paper guide mechanism as the driven roller.

  The ninth aspect of the present invention is an image forming apparatus provided with the paper transport mechanism of the eighth aspect of the present invention.

  According to the present invention as described above, the roller can be detachably held while securing a sufficient strength.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a main part configuration diagram of a paper guide mechanism 1 according to a first embodiment of the present invention. However, in FIG. 1, the same or corresponding parts as those in FIG.

  The paper guide mechanism 1 according to the present embodiment includes a main body portion 10 and a pair of roller portions 20. The main body 10 is provided with a plurality of guide plates 210 arranged at a predetermined interval, and the urging spring 230 is fixed in the same manner as in the conventional example, but is further rectangular as shown in FIGS. 5 and 8a. The hole 11 is opened.

  The roller unit 20 is similar to the conventional example in that it includes a roller shaft 221 and a roller 222 provided on both ends of the roller shaft 221, but further on the end of the roller shaft 221 exposed to the outside of the roller 222. A bearing member 21 is provided.

  The bearing member 21 is fitted in the hole portion 11 of the main body portion 10, and the roller portion 20 is connected to the main body portion 10 via the bearing member 21.

  Next, FIG. 2A is a perspective view showing the configuration of the bearing member 21. As shown in the figure, the bearing member 21 is a member formed by bending a metal plate such as stainless steel, and has a through hole 21b opened on the main surface, and the roller shaft 221 passes through the through hole 21b. By doing so, the bearing member 21 is rotatably held. Further, the through-hole 21b has an oval shape in which the outer shape of the roller shaft 221 indicated by the dotted line in the drawing is accommodated as it is. Accordingly, the roller shaft 221 can move in the through hole 21b along the direction of the urging force of the urging spring 230.

  Further, a lock portion 21 c for fitting into the hole portion 11 of the main body portion 10 is formed at the lower end of the bearing member 21. The lock portion 21c forms a constricted portion α in the middle and has a distal end portion provided with a wedge-shaped leaf spring mechanism. As will be described later, when the lock portion 21c is pushed in until the intermediate portion reaches the hole portion 11 of the main body portion 10, the leaf spring at the front end portion spreads to be fixed to the main body portion 10.

  Further, a pair of contact portions 21 a are provided at both ends of the bearing member 21. The contact portion 21a is formed by bending the main surface at a substantially right angle.

  FIG. 3 shows an enlarged view of the main part D of FIG.

  As shown in FIG. 3, the guide plate 210 of the present embodiment includes four guide plates 210 b and 210 e through which the roller shaft 211 passes, a guide plate 210 c through which the roller 222 passes, and a guide plate 210 d that does not contact the roller portion 20. Consists of different types of guide plates.

  The bearing member 21 is disposed between the guide plate 210e and the guide plate 210d, and the main surface including the through hole 21b abuts on the main surface of the guide plate 210e, while the end of the contact portion 21a is the guide plate. It is in contact with the main surface opposite to the main surface of 210e. Thereby, the bearing member 21 holds the contact state with the guide plate 210e against the urging force generated by the lock portion 21c toward the end of the roller shaft 211.

  Further, as shown in FIG. 2B, the bearing member 21 has a wedge-shaped tip portion of the lock portion 21c that penetrates from the front surface to the back surface of the main body portion 10 through the hole portion 11 and spreads by the action of a spring. The constricted portion α is fixed to the main body portion 10 by meshing with the edge portion of the hole portion 11.

  Further, the wedge-shaped slope forms an acute angle θ with the back surface of the main body 10. Thereby, when a force is applied to the bearing member 21 in a direction away from the main body portion 10, the wedge-shaped tip portion is deformed so as to close, and the engagement between the constricted portion α and the edge portion of the hole portion 11 is released, The main body 10 can be separated.

  Next, FIG. 4A is a cross-sectional view taken along the line AA ′ of FIG. 3, and FIG. 4B is a schematic diagram illustrating a state where the bearing member 21 is omitted in FIG.

  As shown in FIG. 4 (a), the bearing member 21 is fixed when the constricted part meshes with the edge of the hole 11 of the main body 10 because the distal end portion of the lock portion 21 c spreads through the hole 11. Has been.

  Next, as shown in FIG. 4B, the guide plate 210e that contacts the bearing member 21 is provided with a slit 211e having the same width that communicates with the hole 11 and reaches from the root to the opening. The slit 211e has a width sufficiently larger than the outer diameter of the roller shaft 211, like the slit 211b (see FIG. 13B).

  In the sheet guide mechanism according to the first embodiment of the present invention having the above-described configuration, the roller shaft 211 is rotatably held by the bearing member 21 which is a separate member from the slit 211e, and the roller portion is inserted and pulled out. It is characterized in that 20 is configured to be separable from the main body 10.

  That is, as shown in FIG. 1, FIG. 3, FIG. 4A, etc., the roller portion 20 is composed of a roller shaft 221, a roller 222, and a bearing member 21, but the bearing member 21 is made of metal. Therefore, it is resistant to environmental changes such as heat. Further, since the end of the roller shaft 221 is fixed through the through-hole 21b, the resistance against a physical load caused by the pressure applied from the roller shaft 221 is great. Therefore, wear and deformation of the holding portion of the roller shaft 221 are substantially prevented.

  Further, as shown in FIGS. 2B and 5, the bearing member 21 has a mechanism that is detachably fixed to the hole portion 11 of the main body portion 10, so that the entire roller portion 20 is attached to and detached from the main body portion 10 from the outside. Therefore, it can be easily created as in the conventional example.

  As described above, according to the paper guide mechanism of the present embodiment, it is possible to hold the roller unit 20 detachably from the main body unit 10 while ensuring sufficient strength.

(Embodiment 2)
The paper guide mechanism according to the second embodiment of the present invention differs from the paper guide mechanism 1 according to the first embodiment only in the structure of the bearing member.

  FIG. 6A is a perspective view showing the configuration of the bearing member 31 of the paper guide mechanism of the second embodiment. However, the same or corresponding parts as those in FIG.

  The bearing member 31 according to the present embodiment is a member formed by bending a metal plate such as stainless steel, and the configuration of the through hole 21b and the lock portion 21c is the same as that of the bearing member 21 of the first embodiment. However, the difference is that a pair of elastic contact portions 21d are provided at both ends. The elastic contact portion 21d is formed by bending both ends of a plate serving as a base of the bearing member 31 in two stages, and an obliquely intersecting portion 21d1 bent obliquely with respect to the main surface having the through hole 21b, and the main surface The contact surface 21d2 is parallel to the contact surface 21d2.

  A configuration of the paper guide mechanism of the second embodiment using such a bearing member 31 is shown in the top view of FIG.

  As shown in FIG. 6B, the bearing member 31 is disposed between the guide plate 210e and the guide plate 210d as in the first embodiment, but the main surface including the through hole 21b is the main surface of the guide plate 210e. While the elastic contact portion 21d is in contact with the surface, the contact surface 21d2 is in contact with the main surface opposite to the main surface of the guide plate 210e, and the oblique portion 21d1 is formed between the guide plate 210e and the guide plate 210d. They are arranged so as to form an acute angle φ between them.

  Thereby, like Embodiment 1, the bearing member 31 maintains the contact state with the guide plate 210e against the urging force generated by the lock portion 21c toward the end of the roller shaft 211.

  Further, in the present embodiment, the oblique portion 21d1 has an elastic force by being bent obliquely, so even when it is inserted into another type of main body portion in which the distance between the guide plate 210e and the guide plate 210e is different. It is possible to keep the contact state with each guide plate following the interval.

  In addition, when the space | interval of the guide plate 210e and the guide plate 210e is narrower than the structure shown in FIG. 1, the acute angle (phi) shown in FIG.6 (b) becomes smaller, and when the space | interval is wide, the acute angle (phi) becomes larger.

  In the above description, the elastic contact portion 21d is configured to have the oblique portion 21d1 and the contact surface 21d2 by being bent in two stages, but the end portion of the oblique portion 21d1 is the guide plate. The abutting surface 21d2 may be omitted as long as the main surface can be contacted.

(Embodiment 3)
The paper guide mechanism according to the third embodiment of the present invention has a configuration in which the configuration of the bearing member is different from that of the paper guide mechanism 1 according to the first embodiment and the urging spring 230 is omitted.

  FIG. 7A is a perspective view showing the configuration of the bearing member 41 of the paper guide mechanism of the third embodiment. However, the same or corresponding parts as those in FIG.

  The bearing member 41 according to the present embodiment is a member formed by bending a metal plate such as stainless steel, but the lock portion 21c ′ is more intermediate than the lock portion 21c of the bearing member 21 of the first embodiment. The height h of the constricted part is larger than the thickness of the wall surface of the main body.

  Furthermore, instead of the oval through hole 21b, a circular through hole 21e corresponding to the outer diameter of the roller shaft 221 is provided, and a pair of biasing spring combined contact portions 21f are provided at both ends.

  The biasing spring combined contact portion 21f bends both ends of the plate that is the base of the bearing member 41 at a right angle from the base (parallel to the extending direction of the roller shaft 221), and further the end extends in the direction in which the lock portion 21c extends. It is formed by bending it. Thereby, it has the contact part 21f1 orthogonal to the main surface which has the through-hole 21b, and the elastic part 21f2 extended toward the surface of the main-body part 10. As shown in FIG. The elastic portion 21f2 functions as a leaf spring because it is obliquely bent.

  FIG. 7B shows the configuration of the paper guide mechanism of the third embodiment using such a bearing member 41. However, FIG. 7B is a schematic diagram showing a state where the bearing member 21 is replaced with the bearing member 41 in the AA ′ cross-sectional view of FIG.

  As in the first embodiment, the bearing member 41 is disposed between the guide plate 210e and the guide plate 210d. At this time, since the contact portion 21f1 has a width w corresponding to the distance between the guide plate 210e and the guide plate 210d (see FIG. 7A), the contact portion 21f1 is caused by the lock portion 21c as in the bearing member 21 of the first embodiment. The contact state with the guide plate 210e is maintained against the urging force toward the end of the roller shaft 211 that is generated.

  Further, in the present embodiment, (1) since the through hole 21e corresponds to the outer diameter of the roller shaft 221, the roller shaft 221 is rotatable and fixed to the bearing member 41 without moving in the through hole 21e. . (2) Since the height h of the constricted part is larger than the thickness of the main body part 10, the bearing member 41 has a margin based on the height h of the constricted part by inserting the lock part 21c '. Join. (3) Since the elastic portion 21f2 is provided, the bearing member 41 generates an elastic force in the same direction as the biasing spring 230.

  By providing these configurations (1) to (3), the bearing member 41 can apply an outward biasing force to the roller portion 20, as with the biasing spring 230.

  That is, in the paper guide mechanisms of the first and second embodiments, the roller shaft 221 and the roller 222 are urged by the urging spring 230, so that the distance between the roller portion 20 and the main body portion 10 is the same as that of the through hole 21b. While the sheet guide mechanism of the present embodiment is changed by the gap, the roller shaft 221, the roller 222, and the bearing member 41 are urged by the action of the urging spring / contact portion 21f of the bearing member 41. Thus, the distance between the roller portion 20 and the main body portion 10 changes by a margin based on the height h of the constricted portion 21c ′.

  As a result, the paper guide mechanism of the present embodiment can omit the biasing spring 230 in the configuration of the first embodiment.

  In each of the above embodiments, the paper guide mechanism 1 corresponds to the paper guide mechanism of the present invention, the roller unit 20 corresponds to the roller unit of the present invention, and the main body unit 10 corresponds to the main body unit of the present invention. . The roller shaft 221 corresponds to the roller shaft of the present invention, the roller 222 corresponds to the roller of the present invention, the bearing members 21, 31 and 41 correspond to the bearing member of the present invention, and the guide plate 210e corresponds to the roller of the present invention. It corresponds to at least one guide plate. The main surface of the guide plate 201d facing the guide plate 210 corresponds to the facing surface of the present invention.

  Of the guide plates 210, the guide plates 210b, 201c and 210e correspond to a plurality of guide plates of the present invention, and a virtual surface connecting the ridge lines of the respective guide plates 210 corresponds to the guide surfaces of the present invention.

  The slits 211e, 211b, and 211c correspond to the slits of the present invention.

  Further, the contact portion 21a of the bearing member 21 corresponds to the contact portion of the present invention, and the elastic contact portion 21d of the bearing member 31 corresponds to the contact portion that gives a certain elastic force of the present invention. The contact surface 21d2 corresponds to the contact surface of the present invention, and the biasing spring 230 and the elastic portion 21f2 of the bearing member 41 correspond to the biasing portion of the present invention.

  However, the present invention is not limited to the above configuration. In the above description, the main body portion 10 is a hole indicated by a hatched portion in the drawing, which communicates with the slit 211e of the guide plate 210e, as shown in the plan views of the main part in FIG. 4 (b) and FIG. 8 (a). Although the description has been made assuming that the portion 11 is provided, the hole portion 11 may be configured to be provided independently in the main body portion 10 without communicating with the slit. As long as the bearing member can be inserted, the hole is not limited by its specific position, size, and shape.

  Further, the bearing member 21, 31, or 41 is attached to the hole portion 11 of the main body portion 10 by the lock portions 21c, 21c having a leaf spring mechanism so as to be insertable / removable. You may make it fix a bearing member and a main-body part using the rod-shaped member corresponding to the shape of 11. FIG. Moreover, you may fix using a screw | thread etc. In short, the bearing member and the main body are not limited to specific contents as long as the bearing member and the main body are not detachably mounted.

  In addition, the roller 20 is configured by the roller shaft 221 and the rollers 222 provided at both ends thereof, but the roller 222 may be provided in the middle of the roller shaft 221. In short, the roller portion of the present invention is not limited by the number and arrangement of roller shafts and rollers.

  In the above description, the slit 211e adjacent to the bearing member 21, 31 or 41 has been described as being wider than the outer diameter of the roller shaft 221 as shown in FIG. The same thing as the slit 211a shown in FIG. 13A of the conventional example may be used in which the opening end has a narrower width. At this time, the edge 212 of the opening end contacts the roller shaft 221, but the roller shaft 221 is protected by the bearing member, so that the risk of deformation and breakage of the edge 212 of the slit 211a is reduced. Even if this occurs, the holding state of the roller unit 20 is not affected. At this time, as shown in FIG. 8B, the structure of the main body 10 is provided with a hole 11 ′ for removing the slit 210e, which is indicated by a hatched portion in the figure.

  In the above description, the guide portion of the present invention is composed of a plurality of guide plates 210, but the guide portion may be composed of a single member. In this case, the surface of the member corresponds to the guide surface of the present invention.

  In the above description, the bearing members 21, 31, and 41 are configured to contact the main surface of the guide plate 210a while not contacting the main surface of the guide plate 210d having a slit. The opposing surface does not need to be configured as a surface of the guide plate, and may be provided on any member as long as it can contact the contact portion of the bearing member.

  The paper guide mechanism of the present invention is preferably implemented by being incorporated in the paper transport mechanism 100 in the image forming apparatus shown in FIG. 9 in which precision is particularly required for the urging force of the driven roller. Alternatively, it may be used by being incorporated in a paper transport mechanism at an arbitrary place where paper transport is required. In this case, the paper guide mechanism having the bearing member 41 according to the third embodiment, in which the biasing spring 230 is omitted and the biasing spring combined contact portion 21f is used as the biasing portion, is suitable. Furthermore, an image forming apparatus equipped with this paper transport mechanism is also included in the present invention.

  The present invention has an effect that the roller can be detachably held while securing a sufficient strength, and is useful in a paper guide mechanism, a paper transport mechanism, an image forming apparatus, and the like.

1 is a configuration diagram of a main part of a paper guide mechanism according to a first embodiment of the present invention. (A) Perspective view showing the configuration of the bearing member of the paper guide mechanism of Embodiment 1 of the present invention (b) Diagram for explaining the configuration of the bearing member of the paper guide mechanism of Embodiment 1 of the present invention 1 is a front view showing a main part D of a paper guide mechanism according to a first embodiment of the present invention. (A) AA 'sectional view of FIG. 3 (b) Schematic diagram showing a state in which the bearing member is omitted in FIG. 4 (a) The figure for demonstrating the attachment or detachment state of the main-body part 10 and the roller part 20 in the paper guide mechanism of Embodiment 1 of this invention. (A) Perspective view showing the configuration of the bearing member of the paper guide mechanism of Embodiment 2 of the present invention (b) Diagram for explaining the configuration of the bearing member of the paper guide mechanism of Embodiment 2 of the present invention (A) Perspective view showing the configuration of the bearing member of the paper guide mechanism of the third embodiment of the present invention (b) Diagram for explaining the configuration of the bearing member of the paper guide mechanism of the fourth embodiment of the present invention. (A) The principal part top view of the main-body part 10 of the paper guide mechanism of embodiment of this invention (b) The principal part top view of the other examples of the main-body part 10 of the paper guide mechanism of embodiment of this invention. Schematic configuration diagram of an example of a paper transport mechanism of an image forming apparatus The figure for demonstrating the structure of an example of the paper conveyance mechanism of an image forming apparatus. Main part configuration diagram of a conventional paper guide mechanism The front view which shows the principal part C of the paper guide mechanism by a prior art (A) AA 'sectional view of FIG. 12 (b) BB' sectional view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Paper guide mechanism 10 Main body part 11 Hole part 20 Roller part 21, 31, 41 Bearing member 21a Contact part 21b, 21e Through-hole 21c, 21c 'Lock part 21d Elastic contact part 22f Energizing spring combined contact part 210, 210a, 210b, 210c, 201d, 201e Guide plates 211a, 211b, 211e Slit 221 Roller shaft 222 Roller 230 Energizing spring

Claims (9)

A roller portion having a roller shaft, a roller rotatably attached to the roller shaft, and a bearing member having a through hole through which the roller shaft passes;
A main body portion for holding the roller portion;
An urging portion for applying an urging force to the roller shaft,
The main body is
The roller shaft includes a slit disposed therein, and has a guide portion having a guide surface for guiding paper conveyed by the roller portion;
The biasing portion applies the biasing force in a direction toward the opening end of the slit;
The roller part and the main body part are connected via the bearing member,
The paper guide mechanism, wherein the bearing member is mounted so as to be freely inserted into and removed from the main body. The guide portion has a plurality of guide plates arranged in parallel so that the slits face each other.
The sheet guide mechanism according to claim 1, wherein the bearing member is a plate-like member that comes into contact with at least one of the plurality of guide plates. The guide portion has a facing surface facing the guide plate that contacts the bearing member,
The bearing member is disposed between the guide plate and the facing surface,
The sheet guide mechanism according to claim 2, wherein the bearing member has a contact portion that contacts the facing surface.   The paper guide mechanism according to claim 3, wherein the contact portion is in contact with the opposing surface with a certain elastic force.   The sheet guide mechanism according to claim 3, wherein the contact portion has a contact surface that contacts the opposing surface. The bearing member is fixed to the main body with a force that resists at least the biasing force,
The through hole of the bearing member has a gap in which the roller shaft can move along the direction of the biasing force,
The urging portion is disposed between the roller shaft and the main body portion,
The paper guide mechanism according to claim 1. The bearing member is attached to the main body with a margin that can move along the direction of the biasing force,
The through hole of the bearing member has a gap in which the roller shaft can rotate,
The urging portion is provided on the bearing member,
The paper guide mechanism according to claim 1. A driving roller;
A driven roller that is driven in contact with the drive roller;
A guide portion for guiding paper to a contact portion between the drive roller and the driven roller;
The sheet guide mechanism according to any one of claims 1 to 7 is provided as the guide portion,
A paper transport mechanism having the roller of the roller portion of the paper guide mechanism as the driven roller.   An image forming apparatus comprising the paper transport mechanism according to claim 8.

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