JP2009029549A - Paper separating and feeding mechanism of paper feeder - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce vibration noise of a separating pad or a separating pad mounting member while keeping smooth delivery of paper. <P>SOLUTION: The paper separating and feeding mechanism of a paper feeder consists of a paper feed roller, a mechanism for rotating the paper feed roller, the separating pad contacting with the paper feed roller, the separating pad mounting member for mounting the separating pad, a supporting part arranged at a side wall of a paper feeding cassette for supporting the separating pad mounting member and a coil spring for arranging the separating pad mounting member vibratably for a supporting member and delivers the paper to a contact part of the paper feed roller and the separating pad by rotation of the paper feed roller and separates and feeds the plurality of sheets of paper overlapped at the contact part sheet by sheet to a downstream side. Weight of the separating pad mounting member is decreased and energy of vibration is reduced by structuring the separating pad mounting member by polyamide or polypropylene of which specific gravities are smaller than that of conventional polyacetale. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sheet separating and feeding mechanism of a sheet feeding device that separates and feeds a plurality of sheets overlapped at a contact portion between a sheet feeding roller and a separation pad one by one.

  An image forming apparatus such as a printer or a copying machine includes a paper feeding device that feeds paper to an image forming unit or the like. The sheet feeding device includes, for example, a sheet feeding cassette for loading sheets and a sheet separating and feeding mechanism for separating and feeding sheets loaded in the sheet feeding cassette. The sheet separating and feeding mechanism includes a sheet feeding roller, a mechanism for rotating the sheet feeding roller, a separation pad that contacts the sheet feeding roller, and a separation pad mounting member (pad piece) for mounting the separation pad. In this sheet separating and feeding mechanism, the sheet in the sheet feeding cassette is fed into the contact portion between the sheet feeding roller and the separation pad by the rotation of the sheet feeding roller. When a plurality of sheets fed into the contact portion overlap, the plurality of overlapped sheets are separated by the separation pad and fed one by one downstream.

In the sheet separating and feeding mechanism of the sheet feeding device as described above, the separation pad mounting member is mounted on a support member such as a sheet feeding cassette. This separation pad mounting member is attached to the paper feed cassette through a coil spring or the like so as to vibrate in order to stabilize the behavior of the paper fed into the contact portion and prevent the paper from being scratched or wrinkled. ing.
JP-A-7-133303

  In the paper separating and feeding mechanism, the paper and the separation pad rub against each other when separating the paper. Further, when the paper conveyed to the contact portion is interrupted during the conveyance of the paper, the paper feed roller rotates with no paper in the contact portion, and the paper feed roller and the separation pad directly rub against each other. As a result, a stick-slip phenomenon in which the paper or paper feed roller and separation pad repeatedly slide and stop may occur. If it does so, a loud vibration sound will generate | occur | produce by the fine vibration of a separation pad attachment member.

  In order to prevent the generation of this vibration noise, it is conceivable to fix the separation pad mounting member to a support member such as a paper feed cassette. However, if the separation pad mounting member does not vibrate, the smooth feeding of the paper may be hindered, and the driving load of the paper feed roller may increase or the life may be shortened due to an increase in the amount of wear of the separation pad. There is also a problem that the paper may be damaged when the paper is separated.

  On the other hand, the magnitude of energy generated by the vibration of the separation pad mounting member is proportional to the mass of the separation pad mounting member. The vibration sound generated from the separation pad mounting member is proportional to the magnitude of this energy. Therefore, reducing the weight of the separation pad mounting member leads to suppression of vibration noise generated from the separation pad mounting member.

  The present invention has been made in view of the above-described points, and an object of the present invention is to effectively reduce the vibration noise of the separation pad or the separation pad mounting member while maintaining smooth paper feeding with a simple configuration. An object of the present invention is to provide a sheet separating and feeding mechanism of a sheet feeding device.

  In order to solve the above problems, a sheet separating and feeding mechanism of a sheet feeding device according to the present invention includes a sheet feeding roller, a mechanism that rotates the sheet feeding roller, a separation pad that contacts the sheet feeding roller, and a separation pad to which the separation pad is attached. An attachment member; a support member that supports the separation pad attachment member; and a vibration member that allows the separation pad attachment member to vibrate with respect to the support member. This is a paper separation and feeding mechanism of a paper feeding device that retracts into the contact portion with the separation pad and separates the plurality of overlapping paper at the contact portion and feeds them one by one downstream. The material constituting the separation pad mounting member is a material having a specific gravity smaller than that of polyacetal.

  In the conventional sheet separating and feeding mechanism, the separation pad mounting member is made of polyacetal. On the other hand, in the sheet separating and feeding mechanism of the present invention, the separation pad mounting member is made of a material having a specific gravity smaller than that of polyacetal, so that the weight of the separation pad mounting member can be reduced. When the weight of the separation pad mounting member is reduced, energy generated from the separation pad mounting member due to vibration is reduced, and the vibration noise of the separation pad mounting member is reduced. Thereby, the vibration sound of a separation pad or a separation pad attachment member can be reduced effectively.

  As one embodiment of the above configuration, the material constituting the separation pad mounting member may be polyamide or polypropylene. According to this, compared with the case where the separation pad mounting member is made of polyacetal, the weight can be reduced while maintaining the strength or durability of the separation pad mounting member.

  Further, in the above-described sheet separation and feeding mechanism, as another configuration for reducing the weight of the separation pad mounting member, a part of the component of the separation pad mounting member is removed from the separation pad mounting member. A part may be provided. In this case, the lightening portion may be a slit that penetrates from the separation pad mounting surface of the separation pad mounting member to the back surface of the separation pad mounting surface.

  According to this configuration, the weight of the separation pad mounting member can be reduced with a simple configuration. Further, in the case where the lightening portion is configured by the slit, air bubbles that have entered between the separation pad and the separation pad mounting surface when the separation pad is attached can be released from the slit. Therefore, the efficiency of attaching the separation pad is improved. Further, since the surface of the separation pad can be flattened, the performance of paper separation by the separation pad is improved.

  In addition, the paper separating and feeding mechanism includes a paper feeding cassette for loading paper fed by a paper feeding roller, and the support member is a support portion that supports a separation pad mounting member provided in the paper feeding cassette. The vibration member may be a spring interposed between the separation pad mounting member and the support portion.

  According to the sheet separating and feeding mechanism of the sheet feeding device of the present invention, the vibration noise of the separation pad mounting member can be effectively reduced with a simple configuration while maintaining smooth sheet feeding.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view illustrating an external configuration example of an image forming apparatus including a sheet feeding device according to an embodiment of the present invention. First, the overall configuration of the image forming apparatus will be described with reference to FIG. The image forming apparatus to which the present invention is applied may be any one of a copying machine, a facsimile machine, a printer, or a so-called multifunction machine having these functions as long as the image forming apparatus includes a paper feeding device. . The image forming apparatus 1 shown in FIG. 1 includes a reading unit 2 disposed on the upper side and a recording unit 3 disposed on the lower side.

  The reading unit 2 scans and reads an image on a document, an operation panel 5 attached to the front surface of the image reading device 4, and a hinge mechanism (not shown) on the upper side of the image reading device 4 is opened and closed. A document presser cover 6 is attached. At one end of the document pressing cover 6, an automatic document conveying device (ADF) 7 that conveys the document to the image reading device 4 is installed. The ADF 7 sequentially transports a plurality of documents placed on the document supply tray 8 to the image reading device 4, and discharges the document whose image has been read by the image reading device 4 to the document discharge tray 9.

  On the other hand, the recording unit 3 is provided with a paper feeding device 10 that supplies recording paper (hereinafter referred to as “paper”) and a recording device 11 that records an image on the paper supplied from the paper feeding device 10. Yes. The sheet feeding device 10 includes a sheet feeding cassette 20 for loading sheets, and a sheet separating and feeding mechanism 29 (see FIG. 3) described below for separating and feeding sheets in the sheet feeding cassette 20.

  2 and 3 are diagrams showing the configuration of the paper feeding device 10. FIG. 2 is a schematic plan view of the paper feeding cassette 20. FIG. 3 is a front end portion of the paper feeding cassette 20 in the paper feeding direction and its periphery. It is a schematic sectional side view shown. In the description of the present embodiment, as shown in FIGS. 2 and 3, the direction in which the paper is fed is referred to as a paper feeding direction. Further, “front” or “rear” refers to the front (downstream side) or the rear (upstream side) with respect to the sheet feeding direction.

  The paper feed cassette 20 is formed in a substantially rectangular box shape with the upper part opened, and can be drawn into and out of the cassette storage unit 12. The drawing direction of the paper feed cassette 20 shown in FIG. 1 is the right direction indicated by the arrow in FIG. 2, and the front side of the drawing in FIG.

  In the paper feed cassette 20, a flapper 22 that is installed to be pivotable in the vertical direction about a pivot shaft 21 and a coil spring 23 disposed on the lower surface side of the flapper 22 are provided. The coil spring 23 biases the rotating end of the flapper 22 upward. As shown in FIG. 2, a plate-like end guide 24 is installed at a position adjacent to the rear end of the flapper 22 in the sheet feeding direction. The end guide 24 comes into contact with the rear end portion of the paper W placed on the flapper 22.

  A shaft 25 extending in the horizontal direction perpendicular to the sheet feeding direction is installed above the front end of the flapper 22. A paper feed roller 26 is attached to an intermediate portion of the shaft 25. Both ends of the shaft 25 are pivotally supported on the side walls on both sides with respect to the sheet feeding direction of the sheet feeding cassette 20. The paper feed roller 26 is disposed at a position corresponding to the center in the width direction with respect to the paper feed direction of the flapper 22. Although not shown in detail, when the paper feed cassette 20 is stored in the cassette storage unit 12, a drive transmission mechanism (not shown) installed on the cassette storage unit 12 side is engaged with one end of the shaft 25. As a result, a driving force such as a motor (not shown) provided in the sheet feeding device 10 is transmitted to the shaft 25 and the sheet feeding roller 26 rotates.

  A separation pad attachment member (pad piece) 30 is installed on the front side of the front end side of the flapper 22. A separation pad 35 and a film 36 are attached to the separation pad attachment member 30. FIG. 4 is an exploded perspective view in which the separation pad 35 and the film 36 are removed from the separation pad mounting member 30. FIG. 5 is a perspective view of the front end portion of the paper feed cassette 20 and shows a state where the separation pad attachment member 30 is attached to the paper feed cassette 20. The separation pad mounting member 30 is formed in a substantially rectangular flat plate shape, and has a separation pad mounting surface 30a for mounting the separation pad 35 on the upper surface. A side surface 31 and a rear surface 32 extending downward are formed on both sides and the rear side (rear side in the paper feeding direction) of the separation pad mounting surface 30a. A pair of guide pieces 33 are provided outside the side surfaces 31. The guide piece 33 is composed of a shaft-like protrusion that extends downward along the side surfaces 31. A pair of projecting pins 32 a and 32 a for positioning and fixing the film 36 are formed at the lower end of the rear surface 32.

  A slit 34 is formed in the separation pad mounting surface 30a. Each slit 34 is formed of an elongated groove whose longitudinal direction is along the paper feeding direction, and a plurality of slits 34 are arranged in parallel at predetermined intervals. Each slit 34 penetrates from the separation pad mounting surface 30a to the back side thereof.

  The separation pad 35 is a substantially rectangular plate-like member. The separation pad 35 is made of a material whose friction coefficient with respect to the paper is lower than the friction coefficient with respect to the paper of the paper feed roller 26 and higher than the friction coefficient between the papers. An example of such a material is a urethane-based resin material. The separation pad 35 is attached to the separation pad attachment surface 30a by bonding with an adhesive or the like. The film 36 is a member for facilitating the introduction of the paper into the contact portion 28 between the paper feed roller 26 and the separation pad 35, and is a substantially rectangular sheet-like member. The film 36 is made of a resin material such as a PET resin having a low frictional resistance against the paper. The film 36 is positioned by pins 32 a and 32 a and is attached to the separation pad attachment member 30 so as to cover the rear surface 32 and a part of the rear side of the separation pad 35.

  As shown in FIGS. 3 and 5, the separation pad mounting member 30 is supported by a support portion 40 provided at the upper end portion of the side wall 20 a on the front side of the paper feed cassette 20. The support part 40 consists of the part which hollowed the upper end part of the side wall 20a in the shape in alignment with the external shape of the separation pad attachment member 30. As shown in FIG. A coil spring (vibrating member) 27 is interposed between the lower surface of the separation pad mounting member 30 and the bottom surface of the support portion 40. The coil spring 27 is attached to a shaft portion 45 erected perpendicularly to the bottom surface of the support portion 40 and urges the separation pad attachment member 30 vertically upward. On the other hand, the support portion 40 is formed with a guide groove 43 for movably engaging the guide piece 33 of the separation pad mounting member 30. The guide grooves 43 are formed on both inner side surfaces 41 of the support portion 40 facing both side surfaces 31 of the separation pad mounting member 30. As shown in FIG. 3, the longitudinal direction of the guide groove 43 is along the normal direction of the paper feed roller 26. The guide piece 33 engages with the guide groove 43 while being movable along the longitudinal direction of the guide groove 43. As a result, the separation pad mounting member 30 can move along the normal direction of the paper feed roller 26. Therefore, the separation pad mounting member 30 is biased toward the paper feed roller 26 by the biasing force of the coil spring 27. The separation pad 35 attached to the separation pad attachment member 30 is pressed against the paper feed roller 26. The separation pad mounting member 30 can be vibrated along the normal direction of the paper feed roller 26 by the bias of the coil spring 27. A sheet separating and feeding mechanism 29 including the sheet feeding roller 26 and the separation pad 35 attached to the separation pad attaching member 30 separates a plurality of overlapped sheets and feeds them one by one downstream as described later. Is done.

  Here, measures for reducing the weight of the separation pad mounting member 30 will be described. Conventionally, the material constituting the separation pad mounting member 30 is POM (polyacetal). In that case, as described above, when the separation pad 35 and the separation pad mounting member 30 vibrate due to the stick-slip phenomenon, the vibration generated from the separation pad mounting member 30 is generated by the energy generated from the separation pad mounting member 30. There was a risk. Therefore, in the present embodiment, the material constituting the separation pad mounting member 30 is changed to PA (polyamide) or PP (polypropylene) which is a synthetic resin having a specific gravity smaller than that of POM. Below, the case where PA66 (66 nylon) is used as PA is demonstrated to an example.

  The specific gravity of POM, PA66 and PP is 1.41, 1.12 and 0.89, respectively. Thereby, when the separation pad mounting member 30 is formed in the same shape, the mass is reduced in the order of POM, PA66, PP. Therefore, if PP or PA66 is used as the constituent material of the separation pad mounting member 30, the weight of the separation pad mounting member 30 can be reduced as compared with the case where POM is used.

  In the present embodiment, the slit 34 formed in the separation pad attachment member 30 performs so-called lightening that removes a part of the components of the separation pad attachment member 30 to reduce the weight of the separation pad attachment member 30. . Further, in the conventional separation pad mounting member, a protruding reinforcing rib is formed on the back surface of the separation pad mounting surface 30a. However, in the separation pad mounting member 30 of this embodiment, this reinforcing rib is removed. . Further, the overall thickness of the separation pad mounting member 30 is reduced to about half that of the conventional separation pad mounting member, thereby reducing the overall thickness.

  By combining the weight reduction measures by selecting the material as described above and the weight reduction measures by improving the shape, the separation pad mounting member 30 can be significantly reduced in weight compared to the related art.

  The operation of feeding paper with the paper feeder 10 having the above-described configuration will be described. In the paper feed cassette 20, the upper surface of the front end of the paper W placed on the flapper 22 is in contact with the paper feed roller 26. When the paper feed roller 26 rotates in this state, the paper W is fed into the contact portion 28 between the paper feed roller 26 and the separation pad 35 in order from the uppermost one. At that time, if the paper W is fed into the contact portion 28 in a state where the plurality of papers W are overlapped, the friction coefficient between the paper W and the separation pad 35 is larger than the friction coefficient between the papers W. The lower sheet W in contact with the sheet is stopped by the separation pad 35, and the upper sheet in contact with the sheet feeding roller 26 is sequentially separated and fed downstream. The paper W that is in contact with the separation pad 35 is fed after all of the upper paper is fed.

  When the paper W that contacts the separation pad 35 is fed by the feeding of the paper W, the paper W is rubbed against the separation pad 35, so that the separation pad mounting member 30 is moved up and down by the elastic force of the coil spring 27. Microvibrates in the direction (normal direction of the paper feed roller 26). Here, in the sheet feeding device 10 of the present embodiment, since the above-described weight reduction measures are taken for the separation pad mounting member 30, energy generated from the separation pad mounting member 30 that is a vibration generation source is reduced, and the separation pad is reduced. The vibration noise of the mounting member 30 is reduced. Therefore, even when the separation pad mounting member 30 vibrates when the paper W is fed, the generated vibration noise is greatly reduced as compared with the conventional case.

  In the paper feeding device 10 of this embodiment, the separation pad attachment member 30 is attached to the paper feeding cassette 20 so as to be vibrated as in the conventional case. Therefore, the above-described weight reduction measures can effectively suppress the generation of vibration noise due to the stick-slip phenomenon, while increasing the driving load of the paper feed roller 26, the life of the separation pad 35, or the damage to the paper W. It is possible to prevent the occurrence of problems such as. Therefore, the sheet feeding device 10 can feed the sheet with high reliability while reducing the vibration noise.

  Further, in the sheet feeding device 10, since the weight of the separation pad mounting member 30 is reduced, the vibration energy of the separation pad mounting member 30 is reduced (the amount of vibration is reduced). It is also possible to suppress vibration and vibration sound of the paper feed cassette 20 that easily resonates due to vibration.

  Moreover, according to said slit 34, the weight reduction of the separation pad attachment member 30 can be achieved by simple structure. In addition, by providing the slit 34 on the separation pad mounting surface 30a, air bubbles that enter the bonding surface between the separation pad 35 and the separation pad mounting surface 30a when the separation pad 35 is mounted can be released from the slit 34. Therefore, the efficiency of attaching the separation pad 35 is improved. Further, since the surface of the separation pad 35 is flattened by removing the bubbles, the paper separation performance by the separation pad 35 is improved.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the technical idea described in the claims, the specification, and the drawings. Is possible. It should be noted that any shape, structure, and material not directly described in the specification and drawings are within the scope of the technical idea of the present invention as long as the effects and advantages of the present invention are exhibited. For example, in the above-described embodiment, the case where the support member is a support portion provided in the paper feed cassette and the vibration member is a coil spring interposed between the support portion and the separation pad mounting member has been described. Other members or portions that support the separation pad mounting member may be used, and the vibration member may be another type of elastic member that enables the separation pad mounting member to vibrate with respect to the support member. .

  Moreover, the material which comprises the separation pad attachment member 30 shown by the said embodiment is an example, As a constituent material (for example, synthetic resin) of the separation pad attachment member of this invention, a separation pad attachment member is lighter than before. Any material other than those described above can be used as long as the material can be made into a material. For example, ABS, PC (polycarbonate), PE (polyethylene), PF (phenol), PMMA (methacrylic resin), etc., have a smaller specific gravity than POM.

  Further, the lightening of the separation pad mounting member is not limited to the formation of the slit 34 shown in the above embodiment, and other parts may be removed as long as a part of the components of the separation pad mounting member 30 is removed. May be. Further, the position where the slit 34 is formed is not limited to the separation pad mounting surface 30a, and may be formed at another position.

  In the above embodiment, the case where the paper separation / feed mechanism of the present invention feeds the paper in the paper feed cassette has been described. However, as the paper separation / feed mechanism of the present invention, for example, for example, The present invention is applied to a paper separation / feed mechanism for feeding manual paper placed on a manual feed tray or a paper separation / feed mechanism provided in an ADF for feeding original paper placed on a document tray. It is also possible.

1 is a perspective view illustrating an external configuration example of an image forming apparatus including a sheet feeding device according to an embodiment of the present invention. It is a top view which shows the structural example of a paper feed cassette and a cassette storage part. FIG. 3 is a schematic side sectional view of a front end portion of a paper feed cassette and its periphery. It is a disassembled perspective view of the separation pad attachment member which removed the separation pad and the film. It is the perspective view which looked at the front end part of a paper feed cassette from the front.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Reading part 3 Recording part 4 Image reading apparatus 5 Operation panel 6 Original pressing cover 7 Automatic original conveying apparatus (ADF)
8 Document supply tray 9 Document discharge tray 10 Paper feed device 11 Recording device 12 Cassette storage unit 20 Paper feed cassette 20a Side wall 21 Rotating shaft 22 Flapper 23 Coil spring 24 End guide 25 Shaft 26 Paper feed roller 27 Coil spring (vibrating member)
28 Contact portion 29 Paper separation and feeding mechanism 30 Separation pad mounting member 30a Separation pad mounting surface 33 Guide piece 34 Slit (thickening portion)
35 Separation pad 36 Film 40 Support part (support member)
41 Inner surface 43 Guide groove 45 Shaft

Claims (6)

A paper feed roller, a mechanism for rotating the paper feed roller, a separation pad that contacts the paper feed roller, a separation pad attachment member for attaching the separation pad, a support member for supporting the separation pad attachment member, A vibration member that allows the separation pad mounting member to vibrate with respect to the support member, and the paper is fed into a contact portion between the paper feed roller and the separation pad by rotation of the paper feed roller, A sheet separating and feeding mechanism of a sheet feeding device that separates the plurality of overlapping sheets at the contact portion and feeds them one by one downstream when the plurality of sheets overlap;
The material constituting the separation pad mounting member is a material having a specific gravity smaller than that of polyacetal, and a paper separation / feed mechanism of a paper feeding device.   2. The sheet separating and feeding mechanism of a sheet feeding device according to claim 1, wherein the material constituting the separation pad mounting member is polyamide.   2. The sheet separating and feeding mechanism of a sheet feeding device according to claim 1, wherein the material constituting the separation pad mounting member is polypropylene.   4. The sheet separating apparatus according to claim 1, wherein the separation pad mounting member is provided with a lightening portion formed by removing a part of a component of the separation pad mounting member. Feeding mechanism.   5. The sheet feeding device according to claim 4, wherein the lightening portion is a slit penetrating from a separation pad mounting surface to which the separation pad is mounted in the separation pad mounting member to a back surface of the separation pad mounting surface. Paper separation and feeding mechanism. A paper cassette for loading paper fed by the paper feed roller;
The support member is a support portion that supports the separation pad mounting member provided in the paper feed cassette, and the vibration member is a spring that is interposed between the separation pad mounting member and the support portion. 6. A sheet separating and feeding mechanism of a sheet feeding device according to claim 1,

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