JP2011104838A - Waste liquid recovering device and ink jet recording apparatus equipped with the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a waste liquid recovering device which can efficiently recover an ink by suppressing a viscosity increase of the ink ejected from a plurality of ink jet heads in an ejection restoration mode. <P>SOLUTION: The waste liquid recovering device 30 includes a plurality of first waste liquid receivers 31 and a second waste liquid receiver 32. The first waste liquid receivers 31 are arranged below the ink jet heads 13, respectively, having first discharge holes 54 capable of discharging the ink received inside at respective bottom parts 50. The second waste liquid receiver 32 is arranged below the plurality of first waste liquid receivers 31, having an opening 58 capable of receiving the ink discharged from each first discharge hole 54 in the top part, and also having a second discharge hole 60 capable of discharging the ink received inside in the bottom part 56. The opening 58 is blocked by a lid body 91 partly constituted of the first waste liquid receivers 31. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a waste liquid collection device that collects ink ejected from nozzles of an inkjet head, and an inkjet recording apparatus including the same.

  2. Description of the Related Art Conventionally, line printers that perform printing using an inkjet head having a large number of nozzles are known as inkjet recording apparatuses. A large number of nozzles are arranged in a line on the nozzle surface of the inkjet head in a direction (sheet width direction) orthogonal to the sheet conveying direction. The sheet is printed by spraying ink from these many nozzles.

  In such an ink jet recording apparatus, the nozzle surface is sealed with a cap in order to prevent the ink from thickening when not in use. May be blocked. For this reason, in the next use, a so-called ejection recovery mode is executed in which the thickened ink is forcibly discharged.

  Patent Document 1 proposes a waste liquid recovery apparatus that can execute the discharge recovery mode as described above. The waste liquid recovery apparatus receives a plurality of first waste liquid receivers that receive ink discharged from a plurality of ink jet heads and naturally drop the ink from the first discharge holes and discharge the ink from the first discharge holes of the first waste liquid receivers. And a second waste liquid receiver that receives the ink and discharges it from the second discharge hole.

  In the waste liquid recovery apparatus disclosed in Patent Document 1, ink is naturally dropped from each first waste liquid receiver and discharged to one second waste liquid receiver, and the ink stored in the second waste liquid receiver is sucked by a discharge pump. The ink can be collected in a waste liquid collection container.

JP 2009-83245 A

  However, since a certain amount of time is required from when the ink is stored in the second waste liquid receiver until the ink is sucked by the discharge pump and discharged from the second discharge hole, the ink is increased in the second waste liquid receiver. The viscosity may progress and the efficiency of waste liquid recovery may decrease.

  Therefore, the present invention has been made in view of the above points, and an object of the present invention is to efficiently collect ink by suppressing increase in viscosity of the ink ejected from the inkjet head in the ejection recovery mode. It is an object of the present invention to provide a waste liquid recovery device that can be used, and an ink jet recording apparatus including the same.

  The present invention relates to a waste liquid recovery apparatus that recovers ink ejected from nozzles formed on a nozzle surface of an ink jet head in an ink jet recording apparatus. The waste liquid recovery device includes a first waste liquid receiver and a second waste liquid receiver. The first waste liquid receiver is disposed below the ink jet head so as to be able to receive ink ejected from the nozzle, and has a first discharge hole at the bottom for discharging the ink received inside. . The second waste liquid receiver is disposed below the first waste liquid receiver and has an opening at the top for receiving the ink discharged from the first discharge hole, and can discharge the ink received inside. A second discharge hole is provided at the bottom. The opening of the second waste liquid receiver is closed by a lid that is partially or entirely configured by the first waste liquid receiver.

  In this configuration, since the opening of the second waste liquid receiver is closed by the lid, air can be prevented from entering and exiting the internal space of the second waste liquid receiver through the opening. As a result, it is possible to prevent the ink ejected from the inkjet head in the ejection recovery mode from being thickened in the second waste liquid receiver, so that the ink can be efficiently collected.

  Here, “closing the opening” means not only the state in which the air is completely blocked from entering and exiting the second waste liquid receiver through the opening, but also most of the opening is blocked by the lid. It also includes a state in which the entry and exit of air into the second waste liquid receiver through the opening is suppressed by being peeled off.

  For example, when the ink jet recording apparatus includes a plurality of the ink jet heads, the ink jet recording apparatus includes a plurality of first waste liquid receivers respectively disposed below the plurality of ink jet heads, The form by which the one part or all was comprised by the said some 1st waste liquid receptacle is mentioned.

  Each of the first waste liquid receivers has a first side wall portion erected upward from the peripheral edge of the bottom portion, and the second waste liquid receiver is secondly erected upward from the peripheral edge of the bottom portion. A lid that extends laterally from the first sidewall and covers the opening from above; and a lid that extends downward from a periphery of the ceiling to the second sidewall. It is preferable to further include an opposing third side wall portion.

  In this configuration, the second side wall and the third side wall face each other so that they overlap each other in the thickness direction. By providing such an overlapping portion, it becomes difficult for air to flow into the second waste liquid receiver through the gap between the second side wall portion and the third side wall portion, so that the air can further enter and exit through the opening. Can be suppressed.

  The waste liquid recovery device preferably includes an urging unit and an elevating unit. The urging means urges the plurality of first waste liquid receivers upward with respect to the second waste liquid receiver. The elevating means urges the plurality of first waste liquid receivers upward by the urging means to cover each nozzle surface of the plurality of inkjet heads with each first waste liquid receiver, and each first waste liquid. The second waste liquid receiver can be moved up and down when the mode is switched to a discharge recovery mode in which ink is discharged from the nozzles on each nozzle face while the receiver is spaced downward from each nozzle face. It is. When the second waste liquid receiver is moved up and down by the lifting means at the time of the mode switching, the second side wall portion is maintained in a state facing the third side wall portion with respect to the third side wall portion. It can move relatively up and down.

  In this configuration, each first waste liquid receiver functions as a cap that covers each nozzle surface in the cap mode. In the discharge recovery mode, each first waste liquid receiver receives ink discharged from the nozzles on each nozzle surface. It functions as a container for discharging ink from the first discharge hole. Further, in this configuration, when the second waste liquid receiver is raised and lowered by the elevating means when the mode is switched between the cap mode and the discharge recovery mode, the second side wall portion is the third side wall portion. It is possible to move in the vertical direction relative to the third side wall while maintaining the state of facing the. Therefore, since the structure in which the second side wall portion and the third side wall portion overlap each other in the thickness direction can be maintained in each mode, the effect of suppressing the entry and exit of air through the opening in each mode can be obtained. Can do.

  Moreover, it is preferable that a seal member for closing these gaps is disposed between the second side wall and the third side wall.

  In this configuration, the entry and exit of air through the opening can be further suppressed by the seal member disposed in the gap between the second side wall and the third side wall.

  Further, the seal member is provided on each of the second side wall portion and the third side wall portion, and the seal members are arranged to face each other so as to be relatively slidable up and down. preferable.

  In this configuration, since the seal member is provided on both the second side wall and the third side wall, and these are arranged to face each other, it is possible to further prevent the air from entering and exiting through the opening. it can. In addition, since these seal members can slide relative to each other, mode switching between the cap mode and the discharge recovery mode can be performed smoothly.

  Further, it is disposed on the upper surface of the bottom portion of the second waste liquid receiver, contacts the lower surface of the bottom portion of the first waste liquid receiver in the cap mode, closes the first discharge hole from below, and in the discharge recovery mode, It is preferable to further include a sealing member that opens the first discharge hole apart from the lower surface of the bottom portion of the first waste liquid receiver. In the case of this configuration, the vertical length of the portion where the seal member of the second side wall portion and the seal member of the third side wall portion face each other in the cap mode is the same as in the discharge recovery mode. It is preferable that it is larger than the separation distance of the upper end part of the said sealing member, and the lower surface of the said bottom part of a said 1st waste liquid receptacle.

  In this configuration, since the sealing member is provided, the airtight state of the space between the nozzle surface and the first waste liquid receiver is further increased in the cap mode, and the ink is further thickened on the nozzle surface. Can be suppressed.

  By the way, in the discharge recovery mode, the separation distance between the upper end of the sealing member and the lower surface of the bottom of the first waste liquid receiver is such that the second waste liquid receiver is compared with the first waste liquid receiver when the cap mode is switched to the discharge recovery mode. This corresponds to a moving distance that moves relatively downward. Therefore, in this configuration, the length in the vertical direction of the portion where the sealing member of the second side wall portion and the sealing member of the third side wall portion oppose each other in the cap mode is made larger than the separation distance. Therefore, even when the mode is switched to the discharge recovery mode, the state in which the seal members of the second side wall portion and the third side wall portion face each other can be maintained. Thereby, it can suppress that the effect which suppresses the entrance / exit of the air through the clearance gap between the said 2nd side wall part and the said 3rd side wall part falls.

  Further, the apparatus further includes a discharge pump capable of sucking ink received in the second waste liquid receiver through the second discharge hole, and the discharge pump has a negative pressure in the second waste liquid receiver in the discharge recovery mode. It is preferable to be able to adjust to this state.

  As described above, the intrusion of air into the second waste liquid receiver is suppressed by closing the second waste liquid receiver with the lid. Therefore, in the discharge recovery mode, the inside of the second waste liquid receiver can be adjusted to a negative pressure state by sucking air and ink inside the second waste liquid receiver through the second discharge hole by the discharge pump. . Thus, when the inside of the second waste liquid receiver becomes a negative pressure, a substantially uniform suction pressure can be applied to each first discharge hole. Thereby, compared with the case where the ink is naturally dropped from each first discharge hole as in the prior art, the ink discharge effect from each first discharge hole can be enhanced, and the ink from each first discharge hole can be increased. The variation in the discharge state can be reduced.

  An ink jet recording apparatus of the present invention includes an ink jet head, and any one of the above-described waste liquid recovery devices that recover ink ejected from the nozzles of the ink jet head.

  As described above, according to the present invention, in the discharge recovery mode, it is possible to provide a waste liquid recovery apparatus that can efficiently recover ink while suppressing increase in viscosity of ink discharged from a plurality of inkjet heads. it can.

1 is a schematic view of an ink jet recording apparatus according to an embodiment of the present invention when viewed from the front side (front side) orthogonal to the sheet conveyance direction (arrow Ks direction). FIG. 2 is a schematic view when the ink jet recording apparatus of FIG. 1 is viewed from the upstream side (right side) in the sheet conveyance direction. (A) is the schematic when the waste liquid collection | recovery apparatus concerning one Embodiment of this invention is seen from upper direction, (b) is when the waste liquid collection | recovery apparatus is seen from the right side (sheet conveyance direction upstream). FIG. (A) is a sectional view taken along line XX of FIG. 3 (a) in a state where the second waste liquid receiver is disposed at the waste liquid recovery position A, and (b) is a second waste liquid receiver disposed at the cap position B. It is XX sectional drawing of Fig.3 (a) in a state. It is the schematic which shows a part of waste-liquid collection | recovery apparatus concerning other embodiment of this invention.

  Hereinafter, a waste liquid recovery apparatus and an ink jet recording apparatus including the same according to an embodiment of the present invention will be described in detail with reference to the drawings. In the following description, “waste liquid” refers to an ink in which air in the ink jet head or a liquid with increased viscosity is discharged from the ink jet head in order to suppress clogging of the ink jet head. In addition, in each figure, illustration is abbreviate | omitted suitably about the member etc. which are unnecessary for description.

  As shown in FIG. 1, the ink jet recording apparatus 10 includes a sheet conveying unit 12 having a conveying belt (sheet conveying member) 11 that carries and conveys a sheet S on the surface, and ink on the sheet S conveyed by the conveying belt 11. And a printing region (printing portion) P having a plurality of inkjet heads 13 for printing by spraying.

  In the example shown in the figure, the ink jet recording apparatus 10 is a four-color full-color type. The plurality of inkjet heads 13 eject black (K), cyan (C), magenta (M), and yellow (Y) ink in order from the upstream side in the sheet conveyance direction (arrow Ks direction) 4. The inkjet heads 13A, 13B, 13C, and 13D are configured. In addition, in the following description, when it is not necessary to distinguish the colors of the respective inkjet heads 13A to 13D or when collectively referred to, they are appropriately described as “inkjet heads 13”. The same applies to the first waste liquid receiver 31 (31A, 31B, 31C, 31D) described later.

  As shown in FIG. 1, the conveyor belt 11 is stretched endlessly between a driving roller 14 and a driven roller 15. The conveyor belt 11 moves (rotates) in the direction of arrow R11 as the motor 16 rotates the drive roller 14 in the direction of arrow R14 (counterclockwise in the figure). A region between the transport belt 11 and each of the inkjet heads 13A to 13D is a print region P.

  A paper feed cassette 17 is disposed below the conveyor belt 11. The sheets S stored in a stacked state in the paper feed cassette 17 are fed from the paper feed cassette 17 by a paper feed roller 18 and further separated one by one by a transport roller 20 and a retard roller 21 for preventing double feed and transported. It is conveyed along the guide 22 to the downstream side. Further, the sheet S is supplied to the conveying belt 11 after the skew is corrected by the registration roller pair 23. At this time, the sheet S is charged by the suction roller 24 to which a charging bias is applied, and is driven on the sheet carrying surface 11a of the conveying belt 11 (on the downstream side of the driven roller 15 in the surface of the conveying belt 11). A portion positioned on the upstream side of the roller 14 is electrostatically attracted and carried.

  The sheet S carried on the sheet carrying surface 11a of the conveyance belt 11 is supplied to the printing area P as the conveyance belt 11 rotates in the direction of arrow R11, and printing is performed by inkjet heads 13A to 13D described later. The sheet S for which printing has been completed is separated from the transport belt 11 and discharged to the paper discharge tray 25.

  Each of the inkjet heads 13A to 13D has a long shape in the sheet width direction (direction orthogonal to the sheet conveyance direction (arrow Ks direction)), and constitutes a so-called line head. In the present embodiment, the four inkjet heads 13A, 13B, 13C, and 13D are arranged at equal intervals from the upstream side to the downstream side in the sheet conveyance direction, as shown in FIG.

  A flat plate-shaped conveyance guide 26 is disposed on the back surface side of the conveyance belt 11 below the inkjet heads 13A to 13D. The transport belt 11 passes through the print region P so that the back surface thereof is rubbed against the transport guide 26. As a result, the gap between the nozzles n of the inkjet heads 13A to 13D, which will be described later, and the sheet S carried and conveyed on the sheet carrying surface 11a of the conveyance belt 11 is adjusted with high accuracy.

  Each inkjet head 13 has a flat nozzle surface N that faces the sheet carrying surface 11 a of the conveyance belt 11. On each nozzle surface N, a large number of nozzles n for ejecting ink are arranged in a line along the sheet width direction. For example, when the resolution of the inkjet recording apparatus 10 is 600 dpi (dots / inch: number of dots per inch), each nozzle n has a diameter of about 20 μm. In this case, the pitch between two adjacent nozzles n is about 40 μm. A large number of nozzles n aligned in a line may be aligned linearly in a line in the sheet width direction, or may be aligned in a staggered pattern in the sheet width direction.

  The ink jet recording apparatus 10 can perform line-by-line printing with the ink jet heads 13 </ b> A to 13 </ b> D on the sheet S carried and conveyed to the print region P by the conveyance belt 11, and can perform four-color full-color printing as a whole. .

  The inkjet heads 31A to 31D are connected to the ink tank 73 via the supply tube 70 (FIG. 3B). The supply tube 70 is bifurcated on the ink tank 73 side and connected to the ink tank 73. One of the two branches is provided with an electromagnetic valve 71, and the other is provided with a supply pump (pressure pump) 72.

  When the ink jet heads 13A to 13D are not used for a long time, the ink thickens or dries in the ink flow path (not shown) from the ink tank 73 to the nozzle n and in the vicinity of the nozzle n. Clogging may occur. When clogging occurs, ink is not ejected from the nozzle n, or even if it is ejected, its ejection speed slows down, so that the ink does not reach an appropriate position on the surface of the sheet S, and printing failure occurs. To do.

  In the present embodiment, in order to suppress the occurrence of such printing defects, a cap mode for sealing the nozzle n is executed when the inkjet heads 13A to 13D are not used, and the viscosity is increased or dried at the start of reuse. An ejection recovery mode for ejecting ink is executed. As shown in FIG. 2, the ink jet recording apparatus 10 further includes a waste liquid collecting device 30 and a moving mechanism 40 in addition to the transport belt 11 and the ink jet heads 13 </ b> A to 13 </ b> D. The cap mode and the discharge recovery mode are mainly executed by the waste liquid recovery device 30 and the moving mechanism 40.

  The waste liquid recovery device 30 is disposed in a region outside the printing region P, that is, in a region behind the conveyor belt 11 so as not to interfere with the printing operation. The waste liquid recovery device 30 includes a lid 91, a second waste liquid receiver 32, a discharge tube 33, a waste liquid recovery container 34, a discharge pump 35, and an elevating mechanism 36 as an elevating means.

  The lid 91 includes a plurality of first waste liquid receptacles 31, a ceiling 92 described later, and a third side wall 93. The plurality of first waste liquid receivers 31 include a total of four first waste liquid receivers 31 </ b> A, 31 </ b> B, 31 </ b> C, 31 </ b> D corresponding to each inkjet head 13. Details of the waste liquid recovery device 30 will be described later.

  The moving mechanism 40 includes a drive motor 41, a drive pulley 42 fixed to the output shaft of the drive motor 41, a driven pulley 43 that is paired with the drive pulley 42, and the drive pulley 42 and the driven pulley 43. And a feed screw 45 integral with the driven pulley 43, and a feed nut 46 screwed to the front end side of the feed screw 45. The feed nut 46 is fixed to a frame 47 that integrally holds the four inkjet heads 13A to 13D.

  When the drive motor 41 is rotated forward (for example, clockwise), this rotation is transmitted to the drive pulley 42, the transmission belt 44, and the driven pulley 43, and the feed screw 45 rotates forward. As a result, the frame 47 and the ink jet heads 13A to 13D integrated with the feed nut 46 move rearward (right side in FIG. 2). And when each inkjet head 13A-13D reaches | attains above each 1st waste liquid receptacle 31A-31D, a sensor (not shown) will detect this and the drive motor 41 will stop. Thereby, the preparation of the discharge recovery mode in which the ink is discharged from each of the inkjet heads 13A to 13D and the waste liquid is collected is completed.

  Next, the waste liquid recovery device 30 will be described in detail with reference to FIGS. 3 and 4.

  The four first waste liquid receivers 31A to 31D are made of metal (for example, aluminum) or synthetic resin, and have sufficient rigidity. Each first waste liquid receiver 31 has a substantially rectangular parallelepiped container shape that is long in the front-rear direction. All of the four first waste liquid receivers 31A to 31D have substantially the same shape. Each first waste liquid receiver 31 has a rectangular bottom portion 50 that is long in the front-rear direction, and four first side wall portions 51 that are erected upward from four sides (peripheries) of the bottom portion 50.

  A first opening 52 formed by the upper edge portions of the four first side wall portions 51 is provided in the upper portion of each first waste liquid receiver 31. The ink ejected from the nozzle n on the nozzle surface N of the inkjet heads 13A, 13B, 13C, 13D is received in the first waste liquid receiver 31 through the first opening 52.

  A guide bar 53 protrudes downward from the center of the bottom 50 on the lower surface 50b side in the longitudinal direction. The guide bar 53 is guided by a second waste liquid receiver 32 described later so as to be vertically movable. As a result, the first waste liquid receivers 31 </ b> A to 31 </ b> D can move up and down (elevate) relative to the second waste liquid receiver 32.

  Two first discharge holes 54 are formed in the bottom 50 at substantially symmetrical positions in the longitudinal direction with respect to the guide bar 53. Each first discharge hole 60 penetrates the bottom 50 in the vertical direction from the upper surface 50a side to the lower surface 50b side. The upper surface 50 a of the bottom 50 receives ink received through the first opening 52.

  The upper surface 50 a is inclined so that the received ink flows toward the first discharge hole 54. However, since this inclination is gentle, in FIG. The ink received by the bottom 50 and having reached the first discharge hole 54 along the inclination of the upper surface 50a either falls naturally through the first discharge hole 54 or is sucked by the discharge pump 35 as will be described later. It falls through the discharge hole 54 and is received by the second waste liquid receiver 32.

  Each first waste liquid receiver 31 has a nozzle sealing member 55 provided in a frame shape along the upper edge portions of the four first side wall portions 51 (along the peripheral edge portion of the first opening portion 52). Yes. The nozzle sealing member 55 is formed of an elastic member (for example, fluorine rubber, PTFE, etc.) that is resistant to ink. The upper surface 55a of the nozzle sealing member 55 is inclined so that the outer peripheral end 55c side is higher than the inner peripheral end 55b side. As a result, as will be described later, the first sealing member 55 is brought into close contact with the nozzle surface N when the first waste liquid receiver 31 is raised and pressed against the nozzle surface N of the inkjet heads 13A to 13D. Can be sealed.

  As shown in FIG. 3A, the second waste liquid receiver 32 is formed so as to cover the lower portions of the four first waste liquid receivers 31A to 31D. That is, the second waste liquid receiver 32 is formed such that the occupied area when viewed from above is larger than the total occupied area of the four first waste liquid receivers 31A to 31D.

  The second waste liquid receiver 32 is formed of the same material as the first waste liquid receivers 31A to 31D, that is, a metal such as aluminum or a synthetic resin, and has a substantially rectangular parallelepiped container shape. The second waste liquid receiver 32 has a rectangular bottom portion 56 and four second side wall portions 57 erected upward from its four sides (peripheries).

  A second opening 58 formed by the upper edge portions of the four second side wall portions 57 is provided in the upper portion of the second waste liquid receiver 32. The ink dropped through each first discharge hole 54 is received in the second waste liquid receiver 32 through the second opening 58.

  The second waste liquid receiver 32 has a bottom portion 56 whose front-rear dimension is longer than the first waste liquid receivers 31A to 31D in the front-rear direction. It is formed to be longer than the dimension from the right end of the waste liquid receiver 31A to the left end of the first waste liquid receiver 31D.

  As shown in FIG. 3A, the second waste liquid receiver 32 has a second discharge hole 60 provided at a position on the right end side and the rear end side of the bottom portion 56. The second discharge hole 60 penetrates the bottom portion 56 in the vertical direction from the upper surface 56a side to the lower surface 56b side. One end of the discharge tube 33 is attached to the lower surface 56 b side of the second discharge hole 60.

  In the second waste liquid receiver 32, the upper surface 56 a at the bottom 56 is inclined toward the second discharge hole 60. However, since this inclination is gentle, in FIG. As a result, the ink dropped from the first discharge holes 54 of the first waste liquid receivers 31 </ b> A to 31 </ b> D to the upper surface 56 a flows toward the second discharge holes 60.

  As shown in FIG. 4A, the second waste liquid receiver 32 has four holes formed at substantially the center of the bottom portion 56 in the front-rear direction and at positions corresponding to the guide bars 53 of the first waste liquid receivers 31. A guide hole 61 is provided. Each guide bar 53 is inserted into each guide hole 61, and the first waste liquid receivers 31A to 31D are supported to be movable up and down.

  Around the guide hole 61 on the upper surface 56 a of the bottom portion 56, a cylindrical leakage prevention wall 62 is provided to prevent ink flowing through the upper surface 56 a of the bottom portion 56 from leaking downward through the guide hole 61. ing. A cover member 63 is attached below the guide hole 61 on the lower surface 56b side of the bottom portion 56 so as to cover the lower ends of the guide hole 61 and the guide bar 53 from below.

  As shown in FIGS. 4A and 4B, a discharge hole sealing member 64 formed of a block-like elastic member is provided on the upper surface 56a of the bottom portion 56 of the second waste liquid receiver 32. The discharge hole sealing member 64 is provided at a position corresponding to the first discharge hole 54 of each of the first waste liquid receivers 31 </ b> A to 31 </ b> D on the upper surface 56 a of the bottom portion 56. The height of the discharge hole sealing member 64 is higher than the leakage prevention wall 62, and the upper end surface of the discharge hole sealing member 64 is formed to a size that can block the opening of the first discharge hole 54.

  The discharge hole sealing member 64 is retracted downward relative to the first waste liquid receiver 31 when the second waste liquid receiver 32 is disposed at the waste liquid collection position A shown in FIG. Then, the first discharge hole 54 is opened. On the other hand, the discharge hole sealing member 64 is in contact with the lower surface 50b of the bottom 50 of the first waste liquid receiver 31 when the second waste liquid receiver 32 is arranged at the cap position B shown in FIG. 1 discharge hole 54 is closed from below.

  As shown in FIGS. 3A and 3B and FIGS. 4A and 4B, the second opening 58 of the second waste liquid receiver 32 is closed by a lid 91. As described above, the lid 91 extends from the first side wall portion 51 of each first waste liquid receiver 31A to 31D and the first waste liquid receiver 31 to the side and covers the second opening 58 from above. Part 92 and four third side wall parts 93 extending downward from the peripheral edge (four end sides) of the top part 92.

  As shown in FIG. 3A, the top portion 92 is also provided between the adjacent first waste liquid receivers 31, and connects between the adjacent first side wall portions 51. As a result, the upper part of the second opening 58 is almost entirely covered with the four first waste liquid receivers 31 and the top 92 except for the first discharge holes 54.

  In the present embodiment, the top portion 92 and the third side wall portion 93 are integrated with the four first waste liquid receivers 31A to 31D. For such integration, the metal material may be integrally formed by press molding or the like, and the resin material may be integrally molded by injection molding or the like. Moreover, after shape | molding the top part 92, the 3rd side wall part 93, and each 1st waste liquid receptacle 31 as a different body, these may be connected (joined).

  The four third side wall portions 93 are formed continuously in the circumferential direction, and have a cylindrical shape with a square cross section. The four third side wall portions 93 are arranged to face the four second side wall portions 57, respectively. Each of the third side wall portions 93 is disposed with a predetermined gap between the third side wall portion 93 and the opposing second side wall portion 57.

  As shown in FIGS. 4A and 4B, seal members 94 and 95 are disposed between the second side wall portion 57 and the third side wall portion 93. The seal member 94 is continuously attached to the outer surfaces of the four second side wall portions 57 in a belt shape along the circumferential direction. The seal member 95 is attached to the inner surfaces of the four third side wall portions 93 in a belt shape continuously along the circumferential direction.

  These seal members 94 and 95 are arranged to face each other so as to be relatively slidable up and down. Specifically, as the material of the seal members 94 and 95, it is preferable to use a material having a small friction coefficient so as to reduce the frictional resistance during sliding. For example, examples of such a material include a fluororesin-based synthetic resin material such as Teflon (registered trademark). For example, this material may be formed into a tape shape and an adhesive layer formed on one surface may be attached to each surface of the second side wall portion 57 and the third side wall portion 93.

  The arrangement positions and widths of the seal members 94 and 95 are not particularly limited, but are preferably provided under the following conditions. That is, as shown in FIG. 4A, the separation distance L1 between the upper end surface of the discharge hole sealing member 64 and the lower surface 50b of the bottom 50 of the first waste liquid receiver 31 in the discharge recovery mode is the cap mode. This corresponds to a moving distance in which the second waste liquid receiver 32 moves downward relative to the first waste liquid receiver 31 when switching from the discharge recovery mode (FIG. 4A) to the discharge recovery mode (FIG. 4B). Therefore, as shown in FIG. 4B, in the cap mode, the portion where the seal member 94 of the second side wall portion 57 and the seal member 95 of the third side wall portion 93 face each other (the portion overlapping in the thickness direction). It is preferable that the length L2 in the vertical direction is greater than the separation distance L1. As a result, even when the mode is switched from the cap mode to the discharge recovery mode, the state in which the seal members 94 and 95 face each other can be maintained.

  Moreover, it is preferable that the vertical length L3 of each of the seal members 94 and 95 is larger than twice the separation distance L1. In this way, when the lengths of the seal members 94 and 95 are provided with a margin, the relative positions of the first waste liquid receiver 31 and the second waste liquid receiver 32 are slightly changed due to the expansion and contraction of the compression spring 65 described later. Even so, the opposing state of the seal members 94 and 95 can be maintained. Thereby, it can suppress that the edge part of the sealing member 94 and the edge part of the sealing member 95 are caught, and the upper end part of the 2nd side wall part 57 and the lower end part of the 3rd side wall part 93 are caught.

  A compression spring (coil spring) 65 as an urging member is disposed between each first waste liquid receiver 31 and the second waste liquid receiver 32. Each compression spring 65 is disposed inside the leakage prevention wall 62 between the lower surface 50 b of the bottom 50 of the first waste liquid receiver 31 and the upper surface 56 a of the bottom 56 of the second waste liquid receiver 32. Each guide bar 53 is inserted into the coil of each compression spring 65. Thus, the first waste liquid receivers 31 </ b> A to 31 </ b> D are biased upward with respect to the second waste liquid receiver 32.

  As shown in FIG. 4A, the compression spring 65 urges the first waste liquid receivers 31A to 31D upward when the second waste liquid receiver 32 is disposed at the waste liquid collection position A, so that the first discharge holes 54 is separated from the discharge hole sealing member 64. On the other hand, as shown in FIG. 4B, when the second waste liquid receiver 32 is disposed at the cap position B, the compression spring 65 is contracted, and the discharge hole sealing member 64 is the lower surface of the first waste liquid receiver 31. The first discharge holes 54 are closed by coming into contact with 50b, and the nozzle sealing members 55 of the first waste liquid receivers 31A to 31D are in close contact with the nozzle surfaces N of the inkjet heads 13A to 13D. Thereby, each nozzle surface N is sealed by the first waste liquid receivers 31A to 31D.

  As shown in FIGS. 4A and 4B, the discharge tube 33 has one end 33 a connected to the second discharge hole 60 of the second waste liquid receiver 32. This connection portion is designed to prevent ink leakage by a cap 66 having an O-ring. As shown in FIG. 2, the other end 33 b of the discharge tube 33 is connected to a waste liquid collection container 34. The discharge tube 33 is configured such that the second waste liquid receiver 32 to which one end portion 33a is connected can be moved up and down, so that the discharge tube 33 is configured by, for example, a plastic tube that can be easily deformed and has a sufficient length. ing.

  The discharge pump 35 is disposed in the middle of the discharge tube 33 and actively discharges the ink stored in the second discharge hole 60 of the second waste liquid receiver 32 to the waste liquid collection container 34.

  The waste liquid collection container 34 is a container for collecting the ink discharged from the second waste liquid receiver 32 through the discharge tube 33 by the discharge pump 35. The waste liquid collecting container 34 is detachably attached to a waste liquid collecting apparatus main body (not shown), and the waste liquid collected from the waste liquid collecting apparatus main body can be appropriately transferred to another container. it can.

  For example, as shown in FIG. 2, the elevating mechanism 36 has four cam members 67 disposed at the four corners of the lower surface 56 b of the bottom portion 56 of the second waste liquid receiver 32, and a motor 68 that rotates these cam members 67. is doing. The cam member 67 is an eccentric cam that rotates about a shaft 67a. When the motor 68 is driven, the cam member 67 rotates while the cam surface at the periphery of the cam member 67 contacts the lower surface 56b of the bottom portion 56 of the second waste liquid receiver 32. Accordingly, the second waste liquid receiver 32 moves between the lower waste liquid collection position A (FIG. 4A) and the upper cap position B (FIG. 4B).

  Next, the operation of the inkjet recording apparatus 10 of the present embodiment will be described.

  As shown in FIG. 2, the inkjet heads 13 </ b> A to 13 </ b> D are arranged at a printing position above the conveyor belt 11 during printing, while being arranged at a retracted position (see a two-dot chain line) in the cap mode and the discharge recovery mode. Is done. Specifically, it is as follows.

  In the inkjet heads 13A to 13D arranged at the printing position at the time of printing, the electromagnetic valve 71 is opened, and ink is ejected from the nozzle n toward the sheet S to perform printing. When printing is completed, the electromagnetic valve 71 is closed.

  When the supply pump 72 is stopped, the moving mechanism 40 is activated, and the ink jet heads 13A to 13D are moved from the printing position to the retracted position. That is, the drive motor 41 of the moving mechanism 40 rotates in reverse, the drive pulley 42, the transmission belt 44, and the driven pulley 43 rotate in reverse, and the feed screw 45 rotates in reverse. As a result, the inkjet heads 13 </ b> A to 13 </ b> D integrated with the feed nut 47 move rearward (rightward in FIG. 2) and are disposed at the retracted position indicated by the two-dot chain line.

  Subsequently, the elevating mechanism 36 operates to raise the second waste liquid receiver 32 from the waste liquid collection position A (FIG. 4A) to the cap position B (FIG. 4B). By disposing the second waste liquid receiver 32 at the cap position B, the first waste liquid receivers 31A to 31D are urged upward by the compression spring 65, and the first sealing member 55 is the nozzle surface of the ink jet heads 13A to 13D. N is pressed. At substantially the same time, the second sealing member 64 on the second waste liquid receiver 32 side closes the first discharge holes 60 of the first waste liquid receivers 31A to 31D (cap mode). Thereby, since the nozzle n located in the 1st waste liquid receptacles 31A-31D is sealed, it can suppress that the ink of the nozzle n vicinity thickens or dries. At this time, the second opening 58 of the second waste liquid receiver 32 is closed by the first waste liquid receiver 31, the top 92, and the third side wall 93 constituting the lid 91.

  When printing is performed again, the ejection recovery mode is executed before the inkjet heads 13A to 13D move to the printing position. That is, in the inkjet heads 13A to 13D, by rotating the drive motor 68 in the reverse direction, the cam member 67 rotates, and the second waste liquid receiver 32 moves (lowers) from the cap position B to the waste liquid collection position A. In this movement process, as the second waste liquid receiver 32 moves downward, the first waste liquid receiver 31 moves upward relative to the second waste liquid receiver 32 by the urging force of the compression spring 65. Further, at the time of this relative movement, the third side wall portion 93 moves upward relative to the second side wall portion 57 while maintaining the opposed state of the second side wall portion 57.

  As a result, as shown in FIG. 4A, the first sealing member 55 is separated from the nozzle surface N, and the second sealing member 64 is lowered to open the first discharge hole 54. . In addition, when the second waste liquid receiver 32 is at the waste liquid recovery position A and during movement from the cap position B to the waste liquid recovery position A, the second opening 58 of the second waste liquid receiver 32 constitutes the lid 91. The first waste liquid receiver 31, the top 92, and the third side wall 93 are closed. In this state, the discharge recovery mode is executed.

  In the discharge recovery mode, when the electromagnetic valve 71 is closed and the supply pump 72 is driven, the ink in the inkjet heads 13A to 13D is pressurized and discharged from the nozzle n. The discharged ink forms a droplet on the nozzle surface N, and when this droplet becomes large, it drops onto the upper surface 50a of the bottom 50 of the first waste liquid receivers 31A to 31D. The dropped ink is guided to the first discharge hole 54 along the inclination of the upper surface 50a, and spontaneously falls from the first discharge hole 54 to the upper surface 56a of the bottom 56 of the second waste liquid receiver 32. The ink that has fallen naturally flows toward the second discharge hole 60 along the inclination of the upper surface 56a. The ink that has reached the second discharge hole 60 is sucked by the discharge pump 35 (see FIG. 2) and is collected in the waste liquid collection container 34 via the discharge tube 33.

  In the discharge recovery mode, when the drive of the supply pump 72 is started and the drive of the discharge pump 35 is also started at the same time, the inside of the second waste liquid receiver 32 is adjusted to a negative pressure state and each first The ink of each first waste liquid receiver 31 can also be sucked through the discharge hole 54. In this case, the ink is not naturally dropped from the first discharge hole 54 but is sucked by the discharge pump 35, so that the ink can be discharged more efficiently.

  When the discharge recovery mode ends, the drive motor 41 of the moving mechanism 40 rotates forward, and the feed screw 45 rotates forward via the drive pulley 42, the transmission belt 44, and the driven pulley 43. As a result, the inkjet heads 13 </ b> A to 13 </ b> D integrated with the feed nut 46 screwed to the feed screw 45 move from the rearward retracted position toward the front and are disposed at the print position above the transport belt 11. Then, printing is performed as appropriate.

  The above embodiment is summarized as follows.

  In the embodiment, since the opening of the second waste liquid receiver is closed by a lid that is partly or entirely constituted by the first waste liquid receiver, the opening is formed in the internal space of the second waste liquid receiver. Air can be prevented from entering and exiting through the opening. As a result, it is possible to prevent the ink ejected from the inkjet head in the ejection recovery mode from being thickened in the second waste liquid receiver, so that the ink can be efficiently collected.

  Further, in the embodiment, each first waste liquid receiver has a first side wall portion standing upward from a peripheral edge of the bottom portion, and the second waste liquid receiver stands upward from a peripheral edge of the bottom portion. A second side wall provided, the lid extending laterally from the first side wall and covering the opening from above, and extending downward from a peripheral edge of the top. And a third side wall portion facing the second side wall portion. That is, in the said embodiment, it has the structure where these overlapped in the thickness direction because the said 2nd side wall part and the said 3rd side wall part oppose. By providing such an overlapping portion, it becomes difficult for air to flow into the second waste liquid receiver through the gap between the second side wall portion and the third side wall portion, so that the air can further enter and exit through the opening. Can be suppressed.

  In the embodiment, the urging means for urging the plurality of first waste liquid receivers upward with respect to the second waste liquid receiver and the mode switching between the cap mode and the discharge recovery mode. Elevating means capable of elevating and lowering the waste liquid receiver in the vertical direction, and when the second waste liquid receiver elevates and lowers by the elevating means during the mode switching, the second side wall portion is connected to the third side wall portion. It can move in the vertical direction relative to the third side wall while maintaining the facing state. Therefore, since the structure in which the second side wall portion and the third side wall portion overlap each other in the thickness direction can be maintained in each mode, the effect of suppressing the entry and exit of air through the opening in each mode can be obtained. Can do.

  In the embodiment, a seal member that closes these gaps is disposed between the second side wall portion and the third side wall portion, so that air enters and exits through the opening. Further restrained by the member.

  Moreover, in the said embodiment, since the said sealing member is provided in both the said 2nd side wall part and the said 3rd side wall part, and these are arrange | positioned facing, the entrance / exit of the air through the said opening part is suppressed further. can do. In addition, since these seal members can slide relative to each other, mode switching between the cap mode and the discharge recovery mode can be performed smoothly.

  In the embodiment, since the sealing member is provided, in the cap mode, the airtight state of the space between the nozzle surface and the first waste liquid receiver is further increased to increase the ink on the nozzle surface. Viscosity can be further suppressed. In addition, the length in the vertical direction of the portion where the seal member of the second side wall portion and the seal member of the third side wall portion face each other in the cap mode is equal to the length of the sealing member in the discharge recovery mode. Since the separation distance between the upper end portion and the lower surface of the bottom portion of the first waste liquid receiver is larger, even if the mode is switched to the discharge recovery mode, the seal members of the second side wall portion and the third side wall portion are The opposing state can be maintained. Thereby, it can suppress that the effect which suppresses the entrance / exit of the air through the clearance gap between the said 2nd side wall part and the said 3rd side wall part falls.

  Further, in the embodiment, the apparatus further includes a discharge pump capable of sucking the ink received in the second waste liquid receiver through the second discharge hole, and the discharge pump is configured to receive the second waste liquid receiver in the discharge recovery mode. Can be adjusted to a negative pressure state. Thereby, compared with the case where the ink is naturally dropped from each first discharge hole as in the prior art, the ink discharge effect from each first discharge hole can be enhanced, and the ink from each first discharge hole can be increased. The variation in the discharge state can be reduced.

  In the above embodiment, the ink stored in the second waste liquid receiver can be sucked by connecting at least one discharge pump to the second discharge hole. Therefore, it can suppress that an apparatus enlarges.

  Note that the present invention is not limited to the above-described embodiment, and various modifications and improvements can be made without departing from the spirit of the present invention. For example, in the embodiment, the case where the third side wall portion 93 of the lid 91 covers the second side wall portion 57 of the second waste liquid receiver 32 from the outside has been described as an example, but the present invention is not limited thereto. For example, as shown in FIG. 5, the lid 91 may be fitted into the second waste liquid receiver 32 through the second opening 58 of the second waste liquid receiver 32. In this case, the third side wall portion 93 of the lid 91 faces the inner side surface of the second side wall portion 57 of the second waste liquid receiver 32.

  Moreover, although the said embodiment gave and demonstrated the case where the sealing member was each arrange | positioned to both the 2nd side wall part and the 3rd side wall part as an example, it sealed only to one of the 2nd side wall part and the 3rd side wall part. A member may be provided.

  In the above-described embodiment, the case where the seal member is disposed between the second side wall portion and the third side wall portion has been described as an example. However, instead of the seal member, a lubricant such as grease is used for the second. You may make it fill between a side wall part and a 3rd side wall part. Further, a seal member, a lubricant, or the like disposed between the second side wall portion and the third side wall portion is not essential, and these can be omitted.

  In the above-described embodiment, a four-color full-color ink jet recording apparatus has been described as an example. However, the present invention can also be applied to an ink jet recording apparatus using five or more colors or a single color ink.

  In the embodiment, the case where both the cap mode and the discharge recovery mode are provided has been described as an example. However, only the discharge recovery mode may be provided.

  Moreover, although the said embodiment gave and demonstrated the case where the cover body had a top part and a 3rd side wall part, the form which abbreviate | omitted the 3rd side wall part may be sufficient. As such a form, for example, in the discharge recovery mode, a structure in which the opening of the second waste liquid receiver is blocked by the first waste liquid receiver and the top portion extending laterally from the side wall portion can be exemplified.

  Moreover, although the said embodiment gave and demonstrated as an example the case where a cover body contains a 1st waste liquid receptacle, a top part, and a 3rd side wall part, the said cover body consists of one or several 1st waste liquid receptacles. It may be a thing. That is, the lid body may be configured only from the first waste liquid receiver. In this case, the opening part of the second waste liquid receiver is closed by, for example, the bottom part and the first side wall part of one or more first waste liquid receivers.

  Moreover, although the said embodiment gave and demonstrated the case where the discharge hole sealing member 64 formed with the block-shaped (cuboid shape) elastic member was provided as an example, it is not limited to this. As the discharge hole sealing member, for example, a cone shape, a pyramid shape, a shape in which a cone or a pyramid is cut off (having a trapezoidal cross section), or the like may be used. In the case of these shapes, if the ink dropped from the first discharge hole 54 adheres to the sealing member, it easily flows to the bottom of the second waste liquid receiver along the inclination of the side surface of the sealing member.

  Moreover, about the magnitude | size and arrangement | positioning position of a 1st discharge hole and a 2nd discharge hole, it can set arbitrarily.

DESCRIPTION OF SYMBOLS 10 Inkjet recording apparatus 11 Conveyance belt (sheet conveyance member)
13, 13A, 13B, 13C, 13D Inkjet head 30 Waste liquid recovery device 31 First waste liquid receiver 32 Second waste liquid receiver 33 Discharge tube 34 Waste liquid recovery container 35 Discharge pump 36 Lifting mechanism 40 Moving mechanism 50 Bottom 52 Opening 54 First discharge Hole 55 Nozzle sealing member 56 Bottom 60 Second discharge hole 64 Discharge hole sealing member 65 Compression spring (biasing member)
81 Second opening 91 Lid A Waste liquid collection position B Cap position N Nozzle surface n Nozzle P Print area (print section)

Claims (9)

A waste liquid recovery device that recovers ink ejected from nozzles formed on a nozzle surface of an inkjet head in an inkjet recording apparatus,
A first waste receiver that is disposed below the inkjet head so as to be able to receive ink ejected from the nozzle and has a first discharge hole at the bottom that can discharge the ink received inside;
The upper portion has an opening that is disposed below the first waste liquid receiver and can receive the ink discharged from the first discharge hole, and the second discharge hole that can discharge the ink received inside is formed at the bottom. A second waste liquid receiver,
The waste liquid collecting apparatus according to claim 1, wherein the opening of the second waste liquid receiver is closed by a lid that is partially or entirely configured by the first waste liquid receiver. The inkjet recording apparatus includes a plurality of the inkjet heads;
A plurality of the first waste liquid receivers disposed respectively below the plurality of inkjet heads;
The waste liquid recovery apparatus according to claim 1, wherein a part or all of the lid body is configured by the plurality of first waste liquid receivers. Each first waste liquid receiver has a first side wall portion erected upward from a peripheral edge of the bottom portion,
The second waste liquid receiver has a second side wall portion erected upward from a peripheral edge of the bottom portion,
The lid includes a top that extends laterally from the first side wall and covers the opening from above, and a third side wall that extends downward from the periphery of the top and faces the second side wall. The waste liquid recovery device according to claim 2, further comprising: Biasing means for biasing the plurality of first waste liquid receivers upward with respect to the second waste liquid receiver;
A cap mode that urges the plurality of first waste liquid receivers upward by the urging means to cover each nozzle surface of the plurality of inkjet heads with each first waste liquid receiver, and each first waste liquid receiver has each nozzle surface. Elevating means capable of elevating and lowering the second waste liquid receiver in the vertical direction at the time of mode switching between the ejection recovery mode in which ink is ejected from the nozzle surface of each nozzle surface in a state separated downward from the nozzle and the ink is collected; Further comprising
When the second waste liquid receiver is raised and lowered by the elevating means at the time of the mode switching, the second side wall portion is kept relative to the third side wall portion while maintaining a state facing the third side wall portion. The waste liquid recovery device according to claim 3, which is movable in a vertical direction.   The waste liquid recovery apparatus according to claim 4, wherein a seal member that closes the gap is disposed between the second side wall and the third side wall.   The said sealing member is provided in each of the said 2nd side wall part and the 3rd side wall part, These seal members are arrange | positioned facing each other so that it can slide up and down relatively. The waste liquid recovery device described. It is disposed on the upper surface of the bottom portion of the second waste liquid receiver, contacts the lower surface of the bottom portion of the first waste liquid receiver in the cap mode, closes the first discharge hole from below, and the first drain hole in the discharge recovery mode. A sealing member that opens away from the lower surface of the bottom of the waste liquid receiver and opens the first discharge hole;
In the cap mode, the vertical length of the portion of the second sidewall portion where the sealing member and the sealing member of the third sidewall portion face each other is the upper end portion of the sealing member in the discharge recovery mode. The waste liquid recovery device according to claim 6, wherein the waste liquid recovery device is larger than a separation distance between the first waste liquid receiver and a bottom surface of the bottom portion. A discharge pump capable of sucking the ink received in the second waste liquid receiver through the second discharge hole;
The waste liquid recovery apparatus according to claim 4, wherein the discharge pump is capable of adjusting the inside of the second waste liquid receiver to a negative pressure state in the discharge recovery mode. An inkjet head;
An ink jet recording apparatus comprising: the waste liquid recovery apparatus according to claim 1, which recovers ink ejected from the nozzles of the ink jet head.

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