Conveyance mechanism and image forming apparatus

Abstract

To provide a conveyance mechanism capable of preventing its conveyance guide from being deformed due to opening / closing operation.SOLUTION: In an inclined conveyance mechanism having a lower side conveyance guide 110 which is located on a lower side of an inclined conveyance path for conveying a sheet-like material by an upward inclination or a downward inclination and guides an undersurface of the sheet-like material, and an upper side conveyance guide 120 which is located on an upper side of the inclined conveyance path and guides a top surface of the sheet-like material, the upper side conveyance guide 120 can be opened / closed around a rotary shaft S disposed along the inclined conveyance path on one side in the width direction of the inclined conveyance path. A portion which is located at the upper end in the inclination direction of the upper side conveyance guide 120 and is separated from the rotary shaft S in the width direction of the inclined conveyance path is biased in the direction of the rotary shaft S by a tension spring 160 as a first biasing member.SELECTED DRAWING: Figure 7B

Description

[Technical Field]

[0001] The present invention relates to a conveying mechanism for conveying a sheet-like material and an image forming apparatus including the conveying mechanism. [Background technology]

[0002] In an image forming apparatus that is composed of one of a copier, a facsimile, a printer, a printing machine, and an inkjet recording device, or a multifunction machine that combines at least two of these, transport mechanisms are provided at multiple locations within the machine body to transport a sheet-like recording medium in a horizontal direction, as well as up and down directions, and inclined upward or downward directions. In these transport mechanisms, the transport mechanisms are configured to be openable and closable in areas where sheet-like recording media are likely to jam, in order to facilitate jam clearance.

[0003] For example, in the image forming apparatus disclosed in Patent Document 1 (JP 2010-195551 A), if a jam occurs in the vertical transport mechanism, the jam is cleared by opening a door. Also, in the transport mechanism that transports the sheet in the horizontal or inclined direction, the jam is cleared by opening the upper transport guide. Summary of the Invention [Problem to be solved by the invention]

[0004] In an inclined conveying mechanism that conveys a sheet in an inclined direction, the upper conveying guide is opened by rotating upward around a pivot shaft disposed on one side of the inclined conveying path. However, because the pivot shaft is inclined, gravity mg acts on the upper conveying guide, creating a force that tends to deform the housing of the upper conveying guide downward along the inclined conveying path.

[0005] If the housing of the upper transport guide were sufficiently rigid, such deformation would not occur. However, the more rigid the housing, the greater the mass m and the greater the gravity mg. Therefore, the reality is that deformation of the upper transport guide is unavoidable, although to varying degrees. When such deformation of the upper transport guide 120 occurs, the axis of the transport roller of the upper transport guide tilts, causing paper skew and paper jams.

[0006] Similarly, skew and jams can occur in a conveyance path that conveys a sheet in the vertical direction, because when a one-side conveyance guide that guides one side of a sheet is opened horizontally, as in the case of the door disclosed in Patent Document 1, the one-side conveyance guide can be deformed by its own weight.

[0007] The present invention has been made in view of the above circumstances, and has as its object to prevent the transport guide of the transport mechanism from being deformed by the opening and closing operation. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the inclined conveying mechanism of the present invention has a lower conveying guide located on the lower side of an inclined conveying path along which a sheet-like material is conveyed at an upward or downward incline, and guiding the lower surface of the sheet-like material, and an upper conveying guide located on the upper side of the inclined conveying path, and guiding the upper surface of the sheet-like material, wherein the upper conveying guide is configured to be openable and closable about a pivot shaft disposed along the inclined conveying path on one side in the width direction of the inclined conveying path, and a portion of the upper conveying guide in the inclined direction, which is separated from the pivot shaft in the width direction of the inclined conveying path, is urged by a first biasing member to rotate about the pivot shaft. approaching It is characterized by being biased in the direction. [Effects of the Invention]

[0009] According to the present invention, it is possible to prevent the transport guide of the transport mechanism from being deformed by the opening and closing operation. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a schematic diagram of an image forming apparatus according to an embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram of an image forming unit. [Figure 3A] FIG. 10 is a side view of the inclined transport mechanism with the upper transport guide closed. [Figure 3B] FIG. 10 is a side view of the inclined transport mechanism with the upper transport guide open. [Figure 3C] FIG. 3C is a diagram showing a jam-clearable area in FIG. 3B. [Figure 4] FIG. 2 is a perspective view showing the mounting state of the gas spring. [Figure 5] 1A and 1B are side and arrow A views showing the relationship of forces acting on the upper conveying guide. [Figure 6A] 10 is a side view showing the relationship of forces acting on the upper transport guide. FIG. [Figure 6B] FIG. 10 is a side view showing a state in which the upper conveying guide is misaligned. [Figure 7A] 10A and 10B are diagrams illustrating the action of the tension spring in the inclined conveying mechanism according to the embodiment in a first open state. [Figure 7B] 10A and 10B are diagrams illustrating the action of the tension spring in the second open state of the inclined conveying mechanism according to the embodiment. [Figure 8] 10 is a perspective view showing the action of a tension spring when the upper transport guide is in a closed state. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] (● Inkjet printer) Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a schematic diagram of an inkjet printer 1 as an image forming apparatus. The inkjet printer 1 is a device that ejects liquid using a line head system, and includes a feed section that feeds in paper P as an object to which the liquid is to be applied (a recording medium or a sheet-like body), a pre-processing section 20, an image forming section 30, a drying section 40, a reversing mechanism section 60, and a paper discharge tray 114. The image forming section 30 is shown in an enlarged view in Fig. 2. An inclined conveying mechanism according to this embodiment, which will be described later, is disposed between the last conveying roller 62 of the reversing mechanism section 60 and the paper discharge tray 114.

[0012] In the inkjet printer 1, a pretreatment liquid is applied (coated) as needed to paper P carried in (supplied) from a carry-in section 10 in a pretreatment section 20, which is a pretreatment means. Then, a liquid is applied in an image forming section 30 to perform the required printing, and after the liquid adhering to the paper P is dried in a drying section 40, the paper P is discharged to a carry-out section 50.

[0013] The carry-in section 10 includes an input tray 11 (lower input tray 11A, upper input tray 11B) that stores multiple sheets of paper P, and a feeding device 12 (12A, 12B) that separates and sends out the sheets of paper P one by one from the input tray 11. The sheets of paper P are supplied from the carry-in section 10 to a pre-processing section 20. The pre-processing section 20 includes an application section 21, which is a treatment liquid application means that applies a treatment liquid to the printing surface of the paper P, for example, to agglomerate the coloring material of the ink and prevent show-through.

[0014] 2, the image forming unit 30 includes a transport drum 31, which is a support member (rotating body) that rotates while supporting the paper P on its peripheral surface, and a droplet ejection unit 32 that ejects liquid toward the paper P supported on the transport drum 31. The image forming unit 30 also includes a transfer drum 34 that receives the paper P sent from the pre-processing unit 20 and transfers the paper P between it and the transport drum 31, and a transfer drum 35 that receives the paper P transported by the transport drum 31 and transfers it to the drying unit 40.

[0015] The transport drum 31 and the transfer cylinder 34, and the transport drum 31 and the transfer cylinder 35 are connected to each other by gears. The paper P is transported while being gripped by the grippers attached to the transport drum 31, the transfer cylinder 34, and the transfer cylinder 35.

[0016] The paper sheet P transported from the pre-processing unit 20 to the image forming unit 30 has its leading edge gripped by a gripping means (paper gripper) provided on the transfer drum 34, and is transported as the transfer drum 34 rotates. The paper sheet P transported by the transfer drum 34 is handed over to the transport drum 31 at a position opposite the transport drum 31.

[0017] Gripping means (paper grippers) are also provided on the surface of the transport drum 31, and the leading edge of the paper sheet P is gripped by the gripping means (paper grippers). A plurality of suction holes are formed in a dispersed manner on the surface of the transport drum 31, and the suction means generates a suction airflow that flows inward from the required suction holes of the transport drum 31. The paper sheet P transferred from the transfer drum 34 to the transport drum 31 has its leading edge gripped by the paper grippers, and is adsorbed and held on the transport drum 31 by the suction airflow of the suction means, and is transported as the transport drum 31 rotates.

[0018] The droplet discharge section 32 is provided with four droplet discharge units 33 (33A to 33D) that discharge droplets. These droplet discharge units 33 (33A to 33D) are radially arranged along the upper outer periphery of the transport drum 31 at equal intervals and symmetrically in FIG.

[0019] The droplet discharge unit 33 is a functional component that discharges and sprays liquid from a nozzle. The liquid to be discharged is not particularly limited as long as it has a viscosity and surface tension that allows it to be discharged from the head, but it is preferable that the viscosity of the liquid be 30 mPa s or less at room temperature and normal pressure, or by heating or cooling.

[0020] The droplet discharge unit 33A can discharge cyan (C) liquid, the droplet discharge unit 33B can discharge magenta (M) liquid, the droplet discharge unit 33C can discharge yellow (Y) liquid, and the droplet discharge unit 33D can discharge black (K) liquid. In addition, droplet discharge units that discharge special liquids such as white and gold (silver) liquid can also be used.

[0021] The ejection operation of each droplet ejection unit 33 of the droplet ejection section 32 is controlled by a drive signal corresponding to the printing information. When the paper P carried on the transport drum 31 passes through an area facing the droplet ejection section 32, liquid of each color is ejected from the ejection unit 33, and an image corresponding to the printing information is printed.

[0022] The paper P to which liquid has been applied by the droplet ejection unit 32 is delivered from the transport drum 31 to the delivery drum 35, and the paper P received by the delivery drum 35 is delivered to the transport mechanism unit 41 and transferred to the drying unit (heating unit) 40. The drying unit 40 dries the liquid that has adhered to the paper P in the image forming unit 30. This causes the water content and other liquid components in the liquid to evaporate, the colorant contained in the liquid to be fixed on the paper P, and curling of the paper P is suppressed.

[0023] The reversing mechanism 60 is a mechanism that reverses the paper P by a switchback method when performing double-sided printing on the paper P that has passed through the drying unit 40. The reversed paper P is sent back upstream of the transfer drum 34 through the conveying path 61 of the image forming unit 30. The paper P conveyed through the reversing mechanism 60 is stacked and held in order on the paper output tray 114.

[0024] (Inclined transport mechanism) 3A and 3B, an inclined conveying mechanism is connected downstream of the final conveying roller 62 of the reversing mechanism section 60. This inclined conveying mechanism forms an inclined conveying path with an upward inclination θ.

[0025] The inclined transport mechanism has a lower transport guide 110 located below the inclined transport path and guiding the lower surface of the paper P, and an upper transport guide 120 located above the inclined transport path and guiding the upper surface of the paper P. A drive-side transport roller 111 for transporting the paper P is disposed below the upper transport guide 120.

[0026] An idler-side transport roller that pairs with the transport roller 111 is disposed on the upper surface of the lower transport guide 110. An entrance-side transport roller 113 is disposed on the right side (entrance side) of the inclined transport mechanism, and a paper discharge roller 112 is disposed on the left side (exit side).

[0027] As shown in Figures 3C and 4, the upper conveying guide 120 is configured to be openable and closable around a pivot shaft S disposed along the inclined conveying path on one side in the width direction of the inclined conveying path. H1, H2 is fixed to the side plate of the inclined conveying mechanism as shown in Fig. 4. By rotating (opening) the upper conveying guide 120 about the rotation axis S from the dashed line position to the solid line position in Fig. 3C, the upper conveying guide 120 can be opened to a height h in Fig. 3B to form a jam clearable area J.

[0028] 3C and 4, a portion of the upper conveying guide 120 that is separated from the rotation axis S is urged in the opening direction of the upper conveying guide 120 by a gas spring 140 serving as a second urging member. This gas spring 140 can reduce the force required to lift and open the upper conveying guide 120 for jam clearance, and can also hold the upper conveying guide 120 in the open state (free stop).

[0029] As shown in Figure 4, the gas spring 140 can be attached to the upper end of the upper conveying guide 120 in the inclined direction, on the end opposite the pivot shaft S in the width direction of the inclined conveying path. By attaching the gas spring 140 in this way, it is possible to ensure a wide jam clearing area J in the left-right direction, as shown in Figure 3C. Furthermore, by positioning the gas spring 140 as far away as possible from the pivot shaft S, it is possible to reduce the lifting force of the upper conveying guide 120, thereby making it possible to reduce the diameter and cost of the gas spring 140 and prevent deformation of the upper conveying guide 120 due to lifting.

[0030] The base end of the gas spring 140 body is pivotally attached to an upper end bracket 122 on one of a pair of reinforcing ribs 121 arranged on the left and right sides of the upper surface of the upper conveying guide 120. The tip of the rod portion of the gas spring 140 is pivotally attached to a support part 150 fixedly arranged on the lower part of the opposite side plate (not shown).

[0031] (● Force acting on the upper transport guide) Next, the relationship of forces acting on the upper transport guide 120 in the open state will be described with reference to Figure 5. The dashed lines in Figures 5(a) and 5(b) indicate the closed position of the upper transport guide 120. In this state, the paper P is transported along the inclined transport path.

[0032] When a paper jam occurs, the upper conveying guide 120 is raised to the position shown by the solid lines in Figures 5(a) and 5(b) in order to clear the jam. That is, the upper conveying guide 120 is rotated upward around the rotation axis S.

[0033] At the rotation position indicated by the solid line in Fig. 5, as shown in Fig. 5(b), gravity mg and moment M1 act on the rotation axis S. m is the mass of the upper conveying guide 120, and g is the gravitational acceleration. M1 is the rotation moment around the rotation axis S due to a component force F1 of gravity mg (see Fig. 6A).

[0034] 6A, gravity mg acting on upper conveying guide 120 can be divided into a force F1 perpendicular to the inclined conveying path (a component of force normal to the roller) and a force F2 parallel to the inclined conveying path (a component of force tangential to the roller). Force F2 acts in a direction that tends to deform the housing of upper conveying guide 120 downward along the inclined conveying path.

[0035] If the housing of the upper transport guide 120 is sufficiently rigid, there is no risk of the housing being deformed by force F2. However, the more rigid the housing, the greater the mass and therefore the greater the gravitational force mg. Therefore, deformation of the upper transport guide 120 is unavoidable, although to varying degrees. When such deformation of the upper transport guide 120 occurs, the position of the transport roller 111 (the position opposite the pivot axis S) shifts (tilts) downward, as shown by the dashed line ⇒ solid line in Figure 6B, which can cause paper skew or paper jams.

[0036] (●Tension spring) 7A and 7B, a tension spring 160 is provided as a first biasing member. This tension spring 160 becomes shorter as the upper conveying guide 120 is opened from the first open state shown in FIG. 7A to the second open state shown in FIG. 7B.

[0037] As will be described below, the tension spring 160 can prevent deformation of the housing of the upper transport guide 120 and tilting of the transport roller 111. The tension spring 160 is inexpensive, and the inclined transport mechanism can be configured easily and at low cost.

[0038] The tension spring 160 is stretched between a bracket 131 disposed on the inner surface of the side plate 130 and a bracket 123 disposed on the upper surface of the upper conveying guide 120. Therefore, when clearing a jam with the upper conveying guide 120 wide open as shown in FIGS. 7A to 7B, the tension spring 160 approaches the pivot axis S in a plan view (as viewed from the arrow B in FIG. 7B), and a component force F3 sin θ of the tension F3 of the tension spring 160 acts upward along the pivot axis S. Here, θ is the inclination angle of the tension spring 160.

[0039] 7B, the direction of F3 sin θ is downward due to the illustration, but because the rotation axis S is inclined toward the depth of the page, the component force F3 sin θ of the tension F3 acts upward along the rotation axis S. This upward component force F3 sin θ is balanced with the component force F2 of gravity mg acting on the upper conveying guide 120 (FIG. 6A), thereby preventing deformation of the housing of the upper conveying guide 120 and tilting of the conveying roller 111.

[0040] Meanwhile, rotation moments M1 and M1' around the rotation axis S act on the upper conveying guide 120. The rotation moments M1 and M1' are due to gravity mg acting on the upper conveying guide 120, and decrease from M1 to M1' as the center of gravity of the upper conveying guide 120 approaches the rotation axis S in the horizontal direction.

[0041] Supporting the rotational moments M1 and M1' only with the gas spring 140 is not desirable in terms of reducing the diameter and cost of the gas spring 140. In this embodiment, a rotational moment M2 (FIG. 8) in the opposite direction to M1 and M1' is obtained by the component force F3cosθ acting on the upper conveying guide 120 in FIG. 7B.

[0042] Therefore, the load on the gas spring 140 is reduced by the rotation moment M2, making it possible to reduce the diameter and cost. In addition, as the load on the gas spring 140 is reduced, deformation of the upper conveying guide 120 can also be prevented.

[0043] While the present invention has been specifically described above based on the embodiments, it goes without saying that the present invention is not limited to the above embodiments and can be modified in various ways within the scope of the technical concept set forth in the claims. For example, although the above embodiments are directed to an inclined conveying mechanism with an upward incline, the present invention can also be applied to an inclined conveying mechanism with a downward incline.

[0044] The present invention can also be applied to a transport mechanism that transports paper P in the vertical direction. In this case, the upper end of a one-side transport guide (typically arranged inside an opening / closing door) that is arranged on one side of the vertical transport path and that is spaced apart from the rotation axis S in the width direction of the transport path is biased in the direction of the rotation axis S by a tension spring that serves as a first biasing member.

[0045] Since the one-side conveying guide opens and closes horizontally around the pivot axis S, there is little need to provide a gas spring 140 for free stopping. However, if you want to open the one-side conveying guide in a pop-up style, you may provide a second biasing member such as a gas spring 140. [Explanation of symbols]

[0046] 1: Inkjet printer (image forming device) 10: Loading section 11: Loading tray 11A: Lower loading tray 11B: Upper loading tray 12, 12A, 12B: Feeding device 20: Pretreatment section 21: Coating section 30: Image forming unit 31: Conveyor drum 32: Droplet ejection section 33A to 33D: Droplet ejection units 34: Transfer body 35: Transfer body 40: Drying section 41: Conveying mechanism section 50: Unloading section 60: Reversing mechanism section 61: Conveying path 62: Conveying roller 110: Lower conveying guide 111: Drive side conveying roller 112: Paper discharge roller 113: Inlet side transport roller 114: Paper output tray 120: Upper transport guide 121: Reinforcement rib 122: Upper bracket 130: Side panel 131: Bracket 140: Gas spring 150: Support part 160: Tension spring J: Jam clearable area P: Paper H1, H2: Hinge section S: Rotating axis [Prior art documents] [Patent documents]

[0047] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-195551

Claims

1. An inclined conveying mechanism having a lower conveying guide located below an inclined conveying path along which a sheet is conveyed at an upward or downward incline, and guiding the lower surface of the sheet, and an upper conveying guide located above the inclined conveying path, and guiding the upper surface of the sheet, The upper conveying guide is configured to be openable and closable around a pivot axis arranged along the inclined conveying path on one side of the width direction of the inclined conveying path, and the upper end of the upper conveying guide in the inclined direction, which is a portion separated from the pivot axis in the width direction of the inclined conveying path, is biased in a direction approaching the pivot axis by a first biasing member.

2. 2. The inclined conveying mechanism according to claim 1, wherein said first biasing member is a tension spring.

3. 3. The inclined transport mechanism according to claim 1, wherein a portion of the upper transport guide spaced from the pivot shaft is biased in an opening direction of the upper transport guide by a second biasing member.

4. 4. The inclined conveying mechanism according to claim 3, wherein the second biasing member is attached to the upper end of the upper conveying guide in the inclined direction, at the end opposite to the pivot shaft in the width direction of the inclined conveying path.

5. 5. The inclined conveying mechanism according to claim 3, wherein the second biasing member is a gas spring.

6. An image forming apparatus comprising the inclined transport mechanism according to any one of claims 1 to 5.

7. A conveying mechanism having a one-side conveying guide located on one side of a conveying path along which a sheet is conveyed in a vertical direction and which guides one side of the sheet, and an opposite-side conveying guide located on the opposite side of the conveying path and which guides the opposite side of the sheet, The one-side conveying guide is configured to be openable and closable around a pivot axis arranged along the conveying path on one side of the width direction of the conveying path, and a portion of the upper end of the one-side conveying guide that is spaced apart from the pivot axis in the width direction of the conveying path is biased by a first biasing member in a direction approaching the pivot axis.

8. 8. The transport mechanism according to claim 7, wherein the first biasing member is a tension spring.

9. 9. The transport mechanism according to claim 7, wherein a portion of the one-side transport guide spaced from the rotation shaft is biased in an opening direction of the one-side transport guide by a second biasing member.

10. 10. The transport mechanism according to claim 9, wherein the second biasing member is attached to an upper end of the one-side transport guide, on an end opposite to the pivot shaft in the width direction of the transport path.

11. 11. The transport mechanism according to claim 9, wherein the second biasing member is a gas spring.

12. An image forming apparatus comprising the transport mechanism according to any one of claims 7 to 11.

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