JP6544062B2 - Sheet discharge device - Google Patents

Description

  The present invention relates to a sheet discharge apparatus for discharging a sheet.

  For example, in the invention described in Patent Document 1, a sheet presser for pressing the curled sheet is provided in order to correct a curl (curling) generated in the sheet discharged to the sheet discharge tray. The sheet presser is a pivotable member, and presses the sheet downward in the vertical direction using gravity acting on the sheet presser.

JP-A-8-119520

  As the size of the sheet increases, the outer diameter dimension of the sheet retainer also increases accordingly. When the sheet pressure increases, the gravity acting on the sheet pressure increases, so the pressing force for pressing the sheet is likely to be excessively large.

  When the pressing force becomes excessively large, the possibility that the sheet discharged to the sheet discharge tray is blocked by the sheet press is high, and thus problems such as sheet discharge failure and sheet placement failure can occur. Sex is high.

  The present invention has been made in view of the above-described point, and an object thereof is to suppress the occurrence of sheet placement failure and the like in a sheet discharging apparatus.

  In the present application, the first sheet discharge tray (11) on which the discharged sheet is placed, the support frame (15) supporting the first sheet discharge tray (11), and the support frame (15) are swingable. A sheet presser (17) for contacting the sheet that has been assembled and discharged toward the first sheet discharge tray (11) from the upper side in the vertical direction to press the sheet toward the first sheet discharge tray (11); And a spring (19) for generating a moment (hereinafter referred to as a spring moment) for rotating (17) upward in the vertical direction.

  Thus, in the present invention, even if the gravity acting on the sheet retainer (17) increases, the moment for rotating the sheet retainer (17) due to the gravity can be relaxed by the spring moment.

  Furthermore, by adjusting the magnitude of the spring moment, that is, the spring coefficient of the spring (19), it is possible to obtain a pressing force suitable for pressing the sheet without adjusting the size of the sheet retainer (17). It can be possible. As described above, according to the present invention, it is possible to suppress the occurrence of sheet placement failure and the like in the sheet discharging apparatus.

  Incidentally, the reference numerals in the parentheses of the respective means and the like are an example showing the correspondence with the specific means and the like described in the embodiments described later, and the present invention is shown by the reference numerals in the parentheses of the respective means and the like It is not limited to the specific means.

FIG. 2 is an external perspective view of the sheet discharge device 10; FIG. 3 is an external perspective view of the sheet discharge device 10 in the stacker mode. FIG. 2 is a central cross-sectional view of the sheet discharge device 10; FIG. 6 is a central cross-sectional view of the sheet discharge device 10 in the stacker mode. FIG. 8 is a top perspective view of the sheet presser 17; It is the A section enlarged view of FIG. FIG. 10 is a bottom perspective view of the sheet presser 17; It is the A section enlarged view of FIG.

  The “invention embodiment” described below shows an example of the embodiment. That is, the invention-specifying matters and the like described in the claims are not limited to the specific means and the structures and the like shown in the following embodiments.

  In the present embodiment, the present invention is applied to a sheet discharge device for an image forming apparatus. Hereinafter, as shown in FIG. 1, the image forming apparatus 1 in which the sheet discharge device 10 is assembled is simply referred to as “image forming apparatus”.

  Arrows or the like indicating the directions given to the respective drawings are provided to facilitate understanding of the relationship between the respective drawings. The present invention is not limited to the directions given in the respective drawings. At least one member or part described with at least the reference numeral is provided except in the case where “plurality”, “two or more”, etc. are described. Hereinafter, embodiments of the present invention will be described with reference to the drawings.

First Embodiment
1. Overview of image forming apparatus (see FIG. 1)
The sheet discharging apparatus 10 according to the present embodiment is assembled on the upper side of the image forming apparatus 1 in the vertical direction of the sheet discharge outlet 2. An image forming unit (not shown) is accommodated in the image forming apparatus 1. The image forming unit forms an image on a sheet. The housing 3 accommodates the image forming unit.

  A sheet discharge tray 3A is provided on the upper surface side of the housing 3 in the vertical direction. A sheet on which an image is formed is placed on the discharge tray 3A. The sheet discharge tray 3A is a portion from which sheets are discharged when the sheet discharge device 10 does not operate. When the sheet discharge device 10 operates, the sheet is discharged to at least one sheet discharge tray among the plurality of sheet discharge trays 11 to 14.

2. 2. Sheet Ejection Device 2.1 Outline of Sheet Ejection Device The sheet ejection device 10, as shown in FIG. 1, has a plurality of sheet discharge trays 11-14. The sheet discharge device 10 discharges a sheet to any one of the plurality of sheet discharge trays 11 to 14 in accordance with the discharge setting set by the user in advance.

  Each of the paper discharge trays 11 to 14 has the same structure, and can discharge one or more discharged sheets. The respective discharge trays 11 to 14 (hereinafter collectively referred to as “first discharge tray 11 etc. when collectively referred to)” are assembled to the support frame 15 (refer to FIG. 3) in a state of being lined up in the vertical direction . The discharged sheets are placed on the upper surfaces of the respective discharge trays 11 to 14 in the vertical direction.

  Among the sheet discharge trays 11 to 14, the sheet discharge tray at the uppermost part in the vertical direction is referred to as a first sheet discharge tray 11. The sheet discharge tray positioned below the first sheet discharge tray 11 in the vertical direction is referred to as a second sheet discharge tray 12.

  The sheet discharge tray positioned below the second sheet discharge tray 12 in the vertical direction is referred to as a third sheet discharge tray 13. The sheet discharge tray positioned below the third sheet discharge tray 13 in the vertical direction is referred to as a fourth sheet discharge tray 14.

  The support frame 15 is configured to have a first support frame, a second support frame, and the like which are disposed on both ends in the horizontal direction across the first sheet discharge tray 11 and the like. The support frame 15 shown in FIG. 3 is a first support frame.

  The first support frame is disposed on one side (right side in the present embodiment) in the horizontal direction across the first sheet discharge tray 11 and the like to support the first sheet discharge tray 11 and the like. The second support frame is disposed on the other side (left side in the present embodiment) in the horizontal direction with the first sheet discharge tray 11 and the like interposed therebetween, and supports the first sheet discharge tray 11 and the like.

  The first support frame and the second support frame have a symmetrical shape. That is, the second support frame has a shape in which the first support frame is reflected on the mirror. Hereinafter, the first support frame and the second support frame will be collectively referred to as the support frame 15.

  The support frame 15 is covered by a frame cover 15A (see FIG. 1). The first sheet discharge tray 11 and the like can be rocked in the vertical direction with respect to the support frame 15. Then, at least the first sheet discharge tray 11 and the third sheet discharge tray 13 are detachably mounted on the support frame 15 by the user, as shown in FIG.

  The sheet discharging apparatus 10 is provided with a plurality of discharging units 11A to 14A that discharge the sheet discharged from the image forming unit, that is, the sheet on which an image is formed toward the sheet discharge trays 11 to 14. As illustrated in FIG. 1, the discharge units 11 </ b> A to 14 </ b> A are provided side by side in the vertical direction so as to correspond to the plurality of sheet discharge trays 11 to 14.

  The discharge unit 11A opens toward the upper surface of the first sheet discharge tray 11 in the vertical direction. The discharge unit 12 </ b> A opens toward the upper surface of the second sheet discharge tray 12 in the vertical direction. The discharge unit 13 </ b> A opens toward the upper surface of the third sheet discharge tray 13 in the vertical direction. The discharge unit 14 </ b> A opens toward the upper surface of the fourth sheet discharge tray 14 in the vertical direction.

  The first sheet discharge tray 11 to the fourth sheet discharge tray 14 have the same shape. That is, as shown in FIG. 3, each of the first sheet discharge trays 11 and the like is a plate-like member configured to have the first placement surface S1 and the second placement surface S2.

  Each of the first placement surface S1 and the second placement surface S2 is a surface provided on the upper surface in the vertical direction of the first paper discharge tray 11 or the like, and a sheet discharged from each of the discharge units 11A to 14A Can be placed.

  Each first placement surface S1 is located closer to the support frame 15 than the corresponding second placement surface S2, that is, closer to the discharge portions 11A to 14A. Each second placement surface S2 is positioned forward in the sheet discharge direction with respect to the corresponding first placement surface S1.

  In the state where the first sheet discharge tray 11 and the like are mounted on the support frame 15, the inclination angle of each second placement surface S2 with respect to the horizontal surface is smaller than the inclination angle of each first placement surface S1 with respect to the horizontal surface. That is, the first sheet discharge tray 11 or the like is configured as a plate-like member bent at the boundary between the first placement surface S1 and the second placement surface S2.

2.2 Sheet Retainer As shown in FIG. 1, a sheet retainer 17 is provided above the first sheet discharge tray 11 in the vertical direction. The sheet presser 17 is assembled to the support frame 15 so as to be able to swing in the vertical direction, as shown in FIGS. 3 and 4.

  The sheet retainer 17 contacts the sheet discharged toward at least the first sheet discharge tray 11 from the upper side in the vertical direction, and presses the sheet to the first sheet discharge tray 11 side. And the spring 19 is provided in the connection site | part of the sheet | seat presser 17 and the support frame 15 (refer FIGS. 5-8).

  The spring 19 is an elastic member that generates a moment (referred to as a spring moment) that causes the sheet presser 17 to rotate upward in the vertical direction, as shown in FIG. That is, support shafts 17C are provided at both ends in the width direction of the sheet retainer 17 (see FIG. 7).

  As shown in FIG. 6, the spring 19 is constituted by a torsion coil spring mounted on the support shaft 17A of one of the pair of support shafts 17C (on the left side in the present embodiment). The width direction is a direction parallel to the swing axis L1 of the sheet retainer 17.

  The amount of elastic deformation of the spring 19 increases as the sheet retainer 17 swings downward in the vertical direction. That is, in the spring 19 according to the present embodiment, the amount of torsional deformation increases as the sheet retainer 17 is displaced downward in the vertical direction.

  When the first sheet discharge tray 11 is removed from the support frame 15, the sheet presser 17 can swing to a position where it can contact the second sheet discharge tray 12, as shown in FIG.

  That is, the magnitude of the spring moment that the spring 19 acts on the sheet retainer 17 is smaller than the magnitude of the vertically downward moment due to the weight of the sheet retainer 17 regardless of the position of the sheet retainer 17.

  The distance L2 (see FIG. 4) from the swinging center of the sheet presser 17 to the second contact position P2 is larger than the distance L1 (see FIG. 3) from the swinging center to the first contact position P1. The first contact position P1 refers to the position of the sheet presser 17 that contacts the first sheet discharge tray 11 (see FIG. 3).

  The second contact position P2 refers to the position of the sheet presser 17 that contacts the second sheet discharge tray 12 (see FIG. 4). Therefore, the portion where the sheet presser 17 contacts the second sheet discharge tray 12 is a position separated from the swinging center from the portion where the sheet presser 17 contacts the first sheet discharge tray 11.

  In the present embodiment, the first contact position P1 is located on the second placement surface S2 of the first sheet discharge tray 11 (see FIG. 3). The second contact position P2 is located on the second placement surface S2 of the second sheet discharge tray 12 (see FIG. 4). The boundary between the first placement surface S1 and the second placement surface S2 refers to a point P3 at which the extension surface of the first placement surface S1 intersects the extension surface of the second placement surface S2 (see FIG. 4). .

  Furthermore, the first contact position P1 is located vertically above the virtual horizontal plane So including the swing center line L1 (see FIG. 3), and the second contact position P2 is vertically lower than the horizontal plane So. Located in (see Figure 4).

  As shown in FIG. 5, the sheet presser 17 has a first presser 17A and a second presser 17B. The first pressing portion 17A is positioned on one end side (right side in the present embodiment) of the swing axis L1 direction, and is positioned on the other end side (left side in the present embodiment) of the swing axis L1. .

  The first pressing portion 17A contacts the sheet at the right end side of the discharged sheet. The second pressing portion 17B contacts the sheet at the left end side of the discharged sheet. The position where the second pressing portion 17B contacts the sheet corresponds to the position where the position where the first pressing portion 17A contacts the sheet is shifted in the direction parallel to the swing axis L1.

  That is, the position at which the second pressing portion 17B projected on a virtual vertical plane orthogonal to the swing axis L1 contacts the sheet, and the position at which the first pressing portion 17A projected on the virtual vertical plane contacts a sheet , Match (see FIGS. 3 and 4).

  As shown in FIG. 5, the first pressing portion 17A and the second pressing portion 17B are connected by a connecting portion 17D and can be integrally rocked. The connecting portion 17D is a portion that extends in the direction of the swing axis L1 and connects the first pressing portion 17A and the second pressing portion 17B.

  In the present embodiment, the connecting portion 17D is provided at a position closer to the support shaft 17C than the second mounting surface S2. The position is a position close to the support shaft 17C to such an extent that the connecting portion 17D and the support frame 15 do not interfere with each other when the sheet retainer 17 swings.

  As shown in FIG. 8, at least one protrusion 17E extending along the sheet discharge direction is provided on the lower surface of the sheet retainer 17 in the vertical direction. In the present embodiment, as shown in FIG. 7, three projections 17E are provided on the lower surface of each of the first pressing portion 17A and the second pressing portion 17B.

  The protrusion 17E, the connecting portion 17D, the first pressing portion 17A, the second pressing portion 17B, and the pair of support shafts 17C are integrally formed of resin. That is, the sheet retainer 17 is one component made of resin.

  In addition, as shown in FIG. 3, each of the discharge sections 11A to 14A is provided with a second sheet retainer 21. As shown in FIG. 1, the sheet retainers 21 are provided on both ends in the width direction of each of the discharge portions 11A to 14A.

  The sheet discharged from the discharge unit 11A is discharged on the front side while being pressed downward in the vertical direction by the pair of sheet presses 21. Then, it is pressed downward in the vertical direction by the first pressing portion 17A and the second pressing portion 17B, that is, the sheet pressing 17 during the discharge.

  When the discharge is completed, the sheet retainer 17 contacts the sheet, and the pair of sheet retainers 21 do not contact the sheet. The force with which the sheet retainer 21 presses the sheet is a moment due to gravity acting on the sheet retainer 21 or a moment due to a spring (not shown) in addition to the moment.

3. Characteristics of the Image Forming Apparatus (Especially, Sheet Ejection Device) According to the Present Embodiment In the present embodiment, even if the gravity acting on the sheet retainer 17 is increased, the sheet retainer 17 is rotated by the gravity. The moment can be relaxed by the spring moment.

  Furthermore, by adjusting the magnitude of the spring moment, that is, the spring coefficient of the spring 19, it is possible to obtain a pressing force suitable for pressing the sheet without adjusting the size of the sheet retainer 17. As described above, according to the embodiment of the present application, it is possible to suppress the occurrence of sheet placement failure and the like in the sheet discharge device.

  In the present embodiment, when the first sheet discharge tray 11 is removed and a sheet is discharged to the second sheet discharge tray 12 (hereinafter, also referred to as a stacker mode), the sheet presser 17 and the second sheet discharge tray 12 There is a large space between them (see FIG. 4).

  For this reason, when the front end in the discharge direction of the discharged sheet collides with the sheet presser 17 and is blocked, the sheet is easily bent so as to be buckled, so that the sheet mounting failure or the like is likely to occur.

  On the other hand, in the present embodiment, in the stacker mode, the spring moment is larger than when the sheet is discharged to the first sheet discharge tray 11 (hereinafter, also referred to as a normal mode).

  Therefore, since the pressing force of the sheet holding member 17 is smaller than that in the case where the spring 19 is not provided or in the normal mode, the sheet is not blocked when the front end in the sheet discharging direction collides. Get into the lower side of the vertical direction. For this reason, it can suppress that the mounting defect of a sheet | seat, etc. generate | occur | produce.

  In the present embodiment, the distance L2 from the swinging center of the sheet presser 17 to the second contact position P2 is larger than the distance L1 from the swinging center to the first contact position P1. As a result, the pressing force that the sheet presser 17 acts on the sheet in the stacker mode is smaller than that in the normal mode, so that it is possible to suppress the occurrence of sheet placement failure and the like.

  That is, a moment (hereinafter referred to as a gravity moment) Mg due to gravity acts on the sheet presser 17 to rotate the sheet presser 17 downward in the vertical direction. The force F by which the sheet presser 17 presses the sheet, that is, the pressing force F is a force generated by the gravitational moment Mg.

  The gravitational moment Mg is the product (Mg = F × L) of the pressing force F and the distance L from the center of the support shaft 17C which is the swing center of the sheet pressure member 17. The gravitational moment Mg is constant from the swing center of the sheet presser 17 to the tip. Therefore, the magnitude of the pressing force F is inversely proportional to the distance L from the center of the support shaft 17C, which is the swing center.

  Further, in the present embodiment, the distance L2 from the center of the support shaft 17C to the second contact position P2 is larger than the distance L1 from the center of the support shaft 17C to the first contact position P1, the pressing force F in the stacker mode is , Smaller than the pressing force F in the normal mode.

  Furthermore, in addition to the difference in pressing force F due to the difference in the contact position of the sheet presser 17 between the normal mode and the stacker mode, the synergetic effect of the difference between the spring moment of the spring 19 in the normal mode and the stacker mode The pressing force exerted on the sheet of the sheet presser 17 in the stacker mode can be reduced as compared with the normal mode or the case where the spring 19 is not provided, and the occurrence of sheet placement failure can be suppressed.

  In the present embodiment, a connecting portion 17D is provided which extends in the direction of the swing axis L1 and connects the first pressing portion 17A and the second pressing portion 17B. As a result, since the first pressing portion 17A and the second pressing portion 17B can be simultaneously swung and displaced, it is possible to improve the taking-out workability when taking out the placed sheet.

  In the present embodiment, at least one protrusion 17E extending along the sheet discharging direction is provided on the lower surface of the sheet retainer 17 in the vertical direction. Thus, the contact area between the sheet presser 17 and the discharged sheet can be reduced while securing the strength of the sheet presser 17. As a result, since the contact resistance between the discharged sheet and the sheet presser 17 can be reduced, the occurrence of sheet placement failure and the like can be suppressed.

  In the present embodiment, the first contact position P1 is vertically above the virtual horizontal plane including the swing center line of the sheet presser 17, and the second contact position P2 is vertically lower than the horizontal plane. To position. Thereby, it can be suppressed that the moment for rotating the sheet presser 17 due to gravity becomes excessively large.

(Other embodiments)
In the above-described embodiment, the spring 19 is mounted on any one of the pair of support shafts 17C, but the present invention is not limited to this. For example, the spring 19 may be mounted on each of the pair of support shafts 17C. A spring 19 may be attached.

In the above-mentioned embodiment, although the spring 19 was a torsion coil spring, it is not limited to this invention, For example, a torsion bar etc. may be sufficient.
In the above embodiment, the elastic force of the spring 19 is made to act directly on the sheet retainer 17 to generate a spring moment, but the present invention is not limited to this, and indirectly via a link or the like. May generate a spring moment.

  In the above-described embodiment, the sheet presser 17 is configured to include the first presser 17A, the second presser 17B, and the connecting unit 17D, but the present invention is not limited to this. For example, the sheet You may comprise the sheet | seat presser 17 by one plate-shaped member which can contact the width direction both ends.

In the embodiment described above, the ridges 17E are provided on the lower surface in the vertical direction of the sheet retainer 17, but the present invention is not limited to this, and the ridges 17E may be eliminated.
In the above-described embodiment, the first contact position P1 is vertically above the virtual horizontal plane So including the swing center line L1, and the second contact position P2 is vertically lower than the horizontal plane So. Although located, the invention is not limited thereto.

  In the above embodiment, the present invention is applied to a sheet discharge apparatus having a plurality of sheet discharge trays, but the application of the present invention is not limited to this, and a sheet discharge apparatus having at least one sheet discharge tray It is applicable. At this time, the one paper discharge tray may not be detachable from the support frame 15.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 2 ... Ejection port 3 ... Housing | casing 3A ... Ejection tray 10 ... Sheet ejection device 11 ... 1st ejection tray 11A ... Ejection part 12 ... 2nd ejection tray 12A ... Ejection part 15 ... Support frame 15A: Frame cover 17C: Support shaft 17A: First pressing part 17B: Second pressing part 17D: Connecting part 17E: Projection 19: Spring S1: First mounting surface S2: Second mounting surface

Claims (9)

In the sheet discharge device for discharging sheets,
A first discharge tray on which the discharged sheet is placed;
A support frame supporting the first sheet discharge tray;
A sheet retainer which is swingably attached to the support frame and contacts the sheet discharged toward the first sheet discharge tray from above in the vertical direction to press the sheet toward the first sheet discharge tray;
A spring that generates a moment that causes the sheet presser to rotate upward in the vertical direction ;
A second sheet discharge tray on which the discharged sheet is placed, the second sheet discharge tray provided vertically below the first sheet discharge tray and supported by the support frame;
Equipped with
The first sheet discharge tray is detachably mounted to the support frame,
The amount of elastic deformation of the spring increases as the sheet retainer swings downward in the vertical direction.
Furthermore, when the first sheet discharge tray is removed from the support frame, the sheet presser can be pivoted to a position where it can contact the second sheet discharge tray . When the position in contact with the first sheet discharge tray in the sheet press is a first contact position, and the position in contact with the second sheet discharge tray in the sheet press is a second contact position,
2. The sheet discharging apparatus according to claim 1 , wherein the distance from the swinging center of the sheet press to the second contact position is larger than the distance from the swinging center to the first contact position. On the upper surface in the vertical direction of the first sheet discharge tray and the upper surface in the vertical direction of the second sheet discharge tray, a first placement surface located on the support frame side and sheet advancing direction from the first placement surface A second mounting surface positioned on the side, and the inclination angle of the second mounting surface to the horizontal surface is smaller than the inclination angle of the first mounting surface to the horizontal surface,
The first contact position is located on the second placement surface of the first sheet discharge tray,
3. The sheet discharging apparatus according to claim 2, wherein the second contact position is located on the second placement surface of the second sheet discharge tray. The sheet presser has a first presser portion located at one end side in the swinging axis direction and a second presser portion located at the other end side in the swinging axis direction.
The first pressing portion contacts the sheet at one end side of the discharged sheet in the swing axial direction, and the second pressing portion contacts the sheet at the other end side of the discharged sheet in the swing axial direction. The sheet ejection apparatus according to any one of claims 1 to 3 , wherein 5. The sheet discharging apparatus according to claim 4 , further comprising: a connecting portion extending in the swing axis direction and connecting the first pressing portion and the second pressing portion. Support shafts are provided at both ends of the sheet presser in the swing axis direction,
The sheet discharging apparatus according to any one of claims 1 to 5 , wherein the spring is a torsion coil spring mounted on at least one of the pair of support shafts. The sheet discharge according to any one of claims 1 to 6 , wherein at least one protrusion extending along the sheet discharge direction is provided on the lower surface of the sheet retainer in the vertical direction. apparatus. The first contact position is located vertically above a virtual horizontal plane including the swing center line of the sheet presser, and the second contact position is located vertically below the horizontal plane. The sheet discharge device according to claim 2 or 3 , wherein In the sheet discharge device for discharging sheets,
A first discharge tray on which the discharged sheet is placed;
A support frame supporting the first sheet discharge tray;
A sheet retainer which is swingably attached to the support frame and contacts the sheet discharged toward the first sheet discharge tray from above in the vertical direction to press the sheet toward the first sheet discharge tray;
A spring that generates a moment that causes the sheet presser to rotate upward in the vertical direction;
Equipped with
The sheet retainer is
A first pressing portion positioned on one end side of the swing axis direction;
A second pressing portion positioned on the other end side of the swing axis direction;
A connecting portion that extends in the swing axis direction at a position on the upstream side of the first pressing portion and the second pressing portion in the sheet discharge direction, and connects the first pressing portion and the second pressing portion;
Have
The first pressing portion contacts the sheet at one end side of the discharged sheet in the swing axial direction, and the second pressing portion contacts the sheet at the other end side of the discharged sheet in the swing axial direction. ,
The lower surfaces of the first and second pressing portions in the vertical direction extend along the sheet discharge direction, and at least one is disposed at a position overlapping at least the connecting portion in the swing axis direction. A sheet discharge device characterized in that a protrusion of