Head unit and inkjet recording device equipped with same

Abstract

To provide a head unit which can suppress liquid leakage from a connection part at the time of exchange of a recording head with a simple configuration, and an inkjet recording device having the same.SOLUTION: A head unit includes a common channel, one or more recording heads, and a joint mechanism. The common channel has a liquid supply path through which one or more liquids containing ink pass. The recording head is attachable / detachable to / from the common channel, and has a plurality of nozzles for discharging the ink. The joint mechanism connects a liquid supply path and a liquid supply port of the recording head. The joint mechanism has a first opening / closing valve, and a connection member. A first opening / closing valve is fixed to the common channel, and opens / closes the liquid supply path. The connection member connects the first opening / closing valve and the liquid supply port. The connection member is movable between a connection position connected to the first opening / closing valve and a retreat position retreated from the connection position, and when the connection member is arranged at the retreat position, a gap is formed between the first opening / closing valve and the connection member.SELECTED DRAWING: Figure 18

Description

[Technical field]

[0001] The present invention relates to a head unit mounted on an inkjet recording apparatus and an inkjet recording apparatus equipped with the same, and more particularly to a mounting structure for a recording head to the head unit. [Background technology]

[0002] Conventionally, in inkjet recording devices such as inkjet printers, ink is discharged from ink discharge nozzles provided in a recording head, and the discharged ink adheres to a recording medium such as paper to form dots. In such inkjet recording devices, it is possible that some of the ink discharge nozzles may have difficulty discharging ink due to clogging or the like, and in such cases, it becomes necessary to replace the recording head.

[0003] In a so-called line head printer, in which the recording head is arranged so that the ink ejection nozzles are arranged across the entire width of the recording medium, if, for example, three recording heads per color are unitized, it is relatively easy to replace the entire head unit, because the flow paths for the ink, cleaning liquid, and other liquids are completed within one head unit.

[0004] However, in most cases, only one print head in a head unit breaks down, and replacing the entire head unit would be costly. Therefore, it is desirable to replace only the failed print head. However, when replacing only one print head, it is necessary to block the liquid flow path, which raises concerns about liquid leakage during replacement.

[0005] As a method for avoiding leakage when replacing a recording head, for example, Patent Document 1 discloses an inkjet recording device in which an inkjet printer detachably holds a cartridge that holds an ink tank containing ink, the negative pressure in the ink tank is increased by a negative pressure increasing mechanism, and the increase in negative pressure by the negative pressure increasing mechanism is stopped when the ink tank is attached to the printer, thereby preventing ink leakage during maintenance such as head replacement.

[0006] Furthermore, Patent Document 2 discloses an inkjet recording device in which an on-off valve for opening and closing an ink supply path is provided on a carriage that carries a recording head, and by operating a head fixing lever, the on-off valve is opened while the recording head is connected to the carriage using a lever attached to the head fixing lever, and the on-off valve is closed when the recording head is separated. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2002-36586 A [Patent Document 2] JP 2006-68994 A Summary of the Invention [Problem to be solved by the invention]

[0008] The method of Patent Document 1 requires the provision of a negative pressure increasing mechanism in the head cartridge, which complicates the configuration and leads to increased costs. In addition, the configuration of Patent Document 1 has an ink tank disposed in the head cartridge, but this cannot be applied to a configuration in which the ink tank is disposed separately from the print head. In addition, in the configuration of Patent Document 2, the supply valve is not opened or closed unless the head fixing lever is operated, so there is a possibility of forgetting to operate the head fixing lever or ink leakage during the time it takes to operate the head fixing lever.

[0009] In view of the above problems, an object of the present invention is to provide a head unit that is capable of suppressing, with a simple configuration, liquid leakage from connecting parts when replacing a recording head, and an inkjet recording apparatus including the same. [Means for solving the problem]

[0010] In order to achieve the above object, a first configuration of the present invention is a head unit that includes a common flow path, one or more recording heads, and a joint mechanism, and is mounted on an inkjet recording device to record an image on a recording medium. The common flow path has a liquid supply path through which one or more types of liquid including ink pass. The recording head is detachable from the common flow path and has a plurality of nozzles that eject ink. The joint mechanism connects the liquid supply path to a liquid supply port of the recording head. The joint mechanism has a first opening / closing valve and a connecting member. The first opening / closing valve is fixed to the common flow path and opens and closes the liquid supply path. The connecting member connects the first opening / closing valve to the liquid supply port. The connecting member is movable between a connecting position where it is connected to the first opening / closing valve and a retracted position retracted from the connecting position, and when the connecting member is placed in the retracted position, a gap is formed between the first opening / closing valve and the connecting member. Effect of the Invention

[0011] According to the first configuration of the present invention, when removing the recording head from the common flow path, the connecting member is placed in the retracted position to form a gap between the first on-off valve and the connecting member, and paper or cloth can be inserted into this gap to absorb ink and cleaning liquid remaining between the first on-off valve and the connecting member. Therefore, leakage of liquid from the connecting portion when replacing the recording head can be suppressed with a simple configuration. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is an explanatory diagram showing a schematic configuration of a printer 100 as an inkjet recording apparatus according to an embodiment of the present invention. [Diagram 2] A plan view of a recording unit 9 included in the printer 100. [Diagram 3]A side view of recording heads 17a to 17c constituting line heads 11Y to 11K of a recording unit 9. [Figure 4] FIG. 2 is a plan view of the recording heads 17a to 17c as viewed from the ink ejection surface F side. [Diagram 5] A schematic diagram showing the internal structure of the ink supply path 40a, the cleaning liquid supply path 40b, and the recording heads 17a to 17c that constitute the line head 11Y of the printer 100. [Figure 6] FIG. 3 is a side view of the head unit 51 as seen from the upstream side in the paper transport direction. [Figure 7] A plan view of the head unit 51 seen from above. [Figure 8] A partially enlarged view of the recording head 17b and its vicinity of the head unit 51. [Figure 9] A side cross-sectional view of a joint mechanism 60a of a recording head 17b [Figure 10] FIG. 4 is a perspective view showing a state in which the first on-off valve 61 is attached to the common flow path 40. [Figure 11] FIG. 1 is a perspective view of a switching member 62 constituting a first opening / closing valve 61. [Figure 12] FIG. 1 is a perspective view of a first opening / closing member 63 constituting a first opening / closing valve 61. [Figure 13] A perspective view of a connecting member 65 [Figure 14] FIG. 1 is a side cross-sectional view of the joint mechanism 60a, showing a state in which the first on-off valve 61 and the second on-off valve 67 are closed. [Figure 15] FIG. 1 is a side cross-sectional view of the joint mechanism 60a, showing a state in which the first on-off valve 61 and the second on-off valve 67 are open. [Figure 16] FIG. 13 is an enlarged view of the joint mechanism 60a and its vicinity on the side of the recording head 17b, showing the state in which the joint mechanism 60a is connected. [Figure 17] FIG. 17 is an enlarged view of the joint mechanism 60a and its vicinity on the side of the recording head 17b, showing a state in which the connecting member 65 has been moved to a retracted position from the state shown in FIG. 16. [Figure 18] 18 is an enlarged perspective view of a gap between the first on-off valve 61 and the connecting member 65 in FIG. 17. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] 1. Configuration of the Inkjet Recording Apparatus Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is an explanatory diagram showing the general configuration of a printer 100 as an inkjet recording device according to one embodiment of the present invention. The printer 100 is equipped with a paper feed cassette 2 which is a paper storage section. The paper feed cassette 2 is located at the bottom inside the printer main body 1. Inside the paper feed cassette 2, paper P, which is an example of a recording medium, is stored.

[0014] A paper feeder 3 is disposed downstream of the paper feed cassette 2 in the paper transport direction, i.e., above the right side of the paper feed cassette 2 in Fig. 1. The paper feeder 3 separates and sends out the paper P one by one toward the upper right of the paper feed cassette 2 in Fig. 1.

[0015] The printer 100 has a first paper transport path 4a inside. The first paper transport path 4a is located in the upper right corner, which is the paper feed direction, of the paper feed cassette 2. The paper P sent out from the paper feed cassette 2 is transported vertically upward along the side of the printer body 1 by the first paper transport path 4a.

[0016] A pair of registration rollers 13 is provided at the downstream end of the first paper transport path 4a in the paper transport direction. Furthermore, a first transport unit 5 and a recording unit 9 are arranged immediately downstream in the paper transport direction of the pair of registration rollers 13. The paper P sent out from the paper feed cassette 2 reaches the pair of registration rollers 13 through the first paper transport path 4a. The pair of registration rollers 13 corrects skewed feed of the paper P and sends the paper P toward the first transport unit 5 (particularly the first transport belt 8 described later) in time with the ink ejection operation performed by the recording unit 9.

[0017] The paper P sent to the first transport unit 5 by the registration roller pair 13 is transported by the first transport belt 8 to a position facing the recording unit 9 (particularly recording heads 17a to 17c described below). An image is recorded on the paper P by ejecting ink from the recording unit 9 onto the paper P. At this time, the ejection of ink in the recording unit 9 is controlled by a control device 110 inside the printer 100.

[0018] In the paper transport direction, a second transport unit 12 is disposed downstream of the first transport unit 5 (on the left side in FIG. 1). The paper P on which an image has been recorded by the recording unit 9 is sent to the second transport unit 12. The ink ejected onto the surface of the paper P is dried while passing through the second transport unit 12.

[0019] In the paper transport direction, a decurler unit 14 is provided downstream of the second transport unit 12 and near the left side surface of the printer body 1. The paper P from which the ink has been dried by the second transport unit 12 is sent to the decurler unit 14, where any curls in the paper P are straightened out.

[0020] In the paper transport direction, a second paper transport path 4b is provided downstream of the decurler unit 14 (upper in FIG. 1). If double-sided recording is not performed, the paper P that has passed through the decurler unit 14 passes through the second paper transport path 4b and is discharged to a paper discharge tray 15a provided outside the left side of the printer 100. A sub-discharge tray 15b is provided below the paper discharge tray 15a to discharge unnecessary paper P (broken paper) that has experienced printing defects or the like.

[0021] A reversing transport path 16 for double-sided recording is provided at the top of the printer body 1, above the recording unit 9 and the second transport unit 12. When double-sided recording is performed, after recording on one side (first side) of the paper P is completed and the paper P passes through the second transport unit 12 and the decurler unit 14, it is sent to the reversing transport path 16 via the second paper transport path 4b.

[0022] After being sent to the reversing transport path 16, the transport direction of the paper P is then switched so that recording can be performed on the other side (second side) of the paper P. The paper P then passes over the top of the printer body 1 and is transported to the right side, passes through the pair of registration rollers 13, and is sent again to the first transport unit 5 with the second side facing up. In the first transport unit 5, the paper P is transported to a position facing the recording section 9, and an image is recorded on the second side by ink ejection from the recording section 9. After double-sided recording, the paper P passes through the second transport unit 12, the decurler section 14, and the second paper transport path 4b in that order, and is discharged to the paper discharge tray 15a.

[0023] In addition, a maintenance unit 19 and a cap unit 20 are disposed below the second transport unit 12. The maintenance unit 19 moves horizontally below the recording unit 9 when performing purging, wipes off ink extruded from the ink ejection ports of the recording head, and collects the wiped ink. Purging refers to the operation of forcibly pushing out ink from the ink ejection ports of the recording head in order to expel thickened ink, foreign matter, and air bubbles from the ink ejection ports. The cap unit 20 moves horizontally below the recording unit 9 when capping the ink ejection surface of the recording head, and then moves further upward to be attached to the underside of the recording head.

[0024] 2 is a plan view of the recording unit 9. The recording unit 9 includes a head housing 10 and line heads 11Y, 11M, 11C, and 11K. The line heads 11Y to 11K are held in the head housing 10 at a height that forms a predetermined gap (for example, 1 mm) with respect to the conveying surface of an endless first conveyor belt 8 that is stretched around a plurality of rollers including a drive roller 6a, a driven roller 6b, and a tension roller (not shown). The drive roller 6a drives the first conveyor belt 8 in the conveying direction of the paper P (the direction of the arrow A).

[0025] Each of the line heads 11Y to 11K has a plurality of (three in this example) recording heads 17a to 17c. The recording heads 17a to 17c are arranged in a staggered pattern along the paper width direction (arrow BB' direction) perpendicular to the paper transport direction (arrow A direction). The recording heads 17a to 17c have a plurality of ink ejection openings 18 (nozzles). The ink ejection openings 18 are arranged at equal intervals in the width direction of the recording head, that is, the paper width direction (arrow BB' direction). From the line heads 11Y to 11K, inks of yellow (Y), magenta (M), cyan (C), and black (K) are ejected toward the paper P transported by the first transport belt 8 through the ink ejection openings 18 of the recording heads 17a to 17c.

[0026] Fig. 3 is a side view of the recording heads 17a to 17c constituting the line heads 11Y to 11K of the recording unit 9, and Fig. 4 is a plan view of the recording heads 17a to 17c as viewed from the ink ejection surface F1 side. Since the recording heads 17a to 17c have the same shape and configuration, Figs. 3 and 4 show the recording heads 17a to 17c in a single drawing. As shown in Figs. 3 and 4, the ink ejection surface (nozzle surface) F1 of the recording heads 17a to 17c is provided with a plurality of nozzle regions Ra to Rd (four blocks in this case) in which a large number of ink ejection ports 18 (see Fig. 2) are arranged. The ink ejection surface F1 is formed of, for example, SUS (stainless steel).

[0027] To the recording heads 17a to 17c constituting each of the line heads 11C to 11K, ink of four colors (cyan, magenta, yellow, and black) is supplied for each of the line heads 11C to 11K from a liquid supply mechanism 50 (see FIG. 5).

[0028] Each of the recording heads 17a to 17c ejects ink from an ink ejection port 18 toward the paper P, which is adsorbed and held on the conveying surface of the first conveyor belt 8 and conveyed, in response to a control signal from a control device 110 (see FIG. 1) and image data received from an external computer. As a result, a color image is formed on the paper P on the first conveyor belt 8 by overlapping four colors of ink: cyan, magenta, yellow, and black. In addition, a cleaning liquid supply unit 30 that supplies cleaning liquid is provided at one end of the recording heads 17a to 17c in the longitudinal direction (arrow BB' direction) perpendicular to the paper conveying direction (arrow A direction). The cleaning liquid supply unit 30 has a number of cleaning liquid supply ports 30a formed therein.

[0029] In the printer 100, when printing starts after a long period of inactivity and between printing operations, in order to clean the ink ejection surfaces F1 of the recording heads 17a to 17c, ink is extruded (purged) from the ink ejection ports 18 of all of the recording heads 17a to 17c, cleaning liquid is supplied from the cleaning liquid supply port 30a to the cleaning liquid supply surface F2, and a recovery operation of the recording heads 17a to 17c is performed in which the ink ejected onto the ink ejection surface F1 is wiped off together with the cleaning liquid by a wiper (not shown) in preparation for the next printing operation. The ink and cleaning liquid wiped off from the ink ejection surface F1 are collected by an ink receiver (not shown).

[0030] Fig. 5 is a schematic diagram showing the internal structure of the ink supply path 40a, cleaning liquid supply path 40b, and recording heads 17a to 17c that constitute the line head 11Y of the printer 100. Note that the line heads 11M to 11K have the same structure, so their explanations are omitted. Also, since the internal structures of the recording heads 17a to 17c are the same, Fig. 5 shows only the internal structure of the recording head 17a.

[0031] As shown in Fig. 5, a common flow path 40 through which ink and cleaning liquid pass is connected to the recording heads 17a to 17c. Two ink supply paths 40a through which ink passes and one cleaning liquid supply path 40b through which cleaning liquid passes are formed in the common flow path 40. The upstream ends of the ink supply path 40a and the cleaning liquid supply path 40b are connected to a liquid supply mechanism 50. The liquid supply mechanism 50 is composed of a tank that contains the ink and cleaning liquid, and a pump (neither of which is shown) that pumps up the ink and cleaning liquid from the tank.

[0032] The two ink supply paths 40a branch into three paths each at the downstream end, totaling six paths, and two paths are connected to the ink ejection ports 18 of the recording heads 17a to 17c. The cleaning liquid supply path 40b branches into three paths at the downstream end, and is connected to the cleaning liquid supply units 30 (see FIGS. 3 and 4) of the recording heads 17a to 17c. The unit including the recording heads 17a to 17c and the common flow path 40 is hereinafter referred to as a head unit 51 (see FIG. 6).

[0033] Each of the recording heads 17a to 17c has a head front portion 41, a head back portion 43, and a heater 44. The head front portion 41 is provided with an ink ejection surface F1 on which a large number of ink ejection orifices 18 are arranged, and a cleaning liquid supply portion 30 that supplies cleaning liquid (see FIG. 4 for both).

[0034] The head rear portion 43 includes an ink heating passage 45, a filter 46, a reservoir tank 47, and a damper 48. The ink supply passage 40a passes through the ink heating passage 45, the filter 46, the reservoir tank 47, and the damper 48 in this order, and is then connected to the ink ejection port 18 of the head front portion 41.

[0035] A heater 44 is disposed between the head front part 41 and the head back part 43. The heater 44 heats the ink in an ink heating flow passage 45 (described later) to a predetermined temperature as necessary, and also heats the head front part 41 so that the ink can be smoothly ejected from the ink ejection orifices 18.

[0036] The ink heating flow path 45 heats the ink in the ink supply path 40a to a predetermined temperature. The ink heating flow path 45 is provided in a position adjacent to the heater 49 in the head back portion 43. The filter 46 removes foreign matter from the ink passing through the ink supply path 40a. The reservoir tank 47 temporarily stores the ink passing through the ink supply path 40a. The damper 48 is formed of a flexible resin film, and by pulsating the damper 48, ink is pushed out to the head front portion 41.

[0037] One of the two ink supply paths 40a is used to supply ink from the liquid supply mechanism 50 to the recording heads 17a to 17c, and the other is used to recover ink from the recording heads 17a to 17c to the liquid supply mechanism 50. When recording an image requiring a large amount of ink ejection, both of the two ink supply paths 40a can be used to supply ink to the recording heads 17a to 17c.

[0038] FIG. 6 is a side view of the head unit 51 as viewed from the upstream side (the right side in FIG. 2) in the paper transport direction. FIG. 7 is a plan view of the head unit 51 as viewed from above. FIG. 8 is a partial enlarged view of the head unit 51 near the recording head 17b. The recording heads 17a to 17c are each individually detachable from the common flow path 40. More specifically, three joint mechanisms 60a to 60c that connect the recording heads 17a to 17c to the common flow path 40 are fastened from above the common flow path 40 by three first fixing screws 55 per location (a total of nine). In addition, both left and right ends of each of the recording heads 17a to 17c are fastened to the common flow path 40 by second fixing screws 57. A heat sink 53 is attached to the side of each of the recording heads 17a to 17c. The heat sink 53 dissipates heat generated from a flexible substrate (not shown) arranged inside.

[0039] The joint mechanism 60a and the joint mechanism 60b are each connected to two ink supply paths 40a (see FIG. 7). The joint mechanism 60c is connected to the cleaning liquid supply path 40b.

[0040] [2. Structure of the joint mechanism] The detailed configuration of the joint mechanisms 60a to 60c will be described below. FIG. 9 is a side cross-sectional view of the joint mechanism 60a of the recording head 17b. FIG. 10 is a perspective view showing a state in which the first on-off valve 61 is attached to the common flow path 40. FIG. 11 is a perspective view of a switching member 62 constituting the first on-off valve 61. FIG. 12 is a perspective view of a first on-off member 63 constituting the first on-off valve 61. FIG. 13 is a perspective view of a connecting member 65. Note that, although the configuration of the joint mechanism 60a of the recording head 17b is illustrated here, the joint mechanisms 60b and 60c have the same configuration as the joint mechanism 60a. The joint mechanisms 60a to 60c of the recording heads 17a and 17c also have the same configuration.

[0041] 9, the joint mechanism 60a includes a first on-off valve 61, a connecting member 65, and a second on-off valve 67. The first on-off valve 61 is attached to the ends of the ink supply path 40a and the cleaning liquid supply path 40b (see FIG. 7) of the common flow path 40. The first on-off valve 61 has a switching member 62 and a first on-off member 63.

[0042] As shown in FIG. 11, the switching member 62 has a hollow, generally cylindrical shape whose diameter gradually decreases upward, and has an insertion hole 62a into which the first opening / closing member 63 is inserted. An engagement boss 62b is protruded from the inner peripheral surface of the insertion hole 62a. A first flange portion 62c, a second flange portion 62d, and a lever portion 62e are formed on the outer peripheral surface of the switching member 62. A first O-ring 80a (see FIG. 9) that seals the gap between the common flow path 40 and the switching member 62 is attached to the first flange portion 62c. A second O-ring 80b (see FIG. 9) that seals the gap between the first opening / closing valve 61 and the connecting member 65 is attached to the second flange portion 62d. The lever portion 62e is pressed in the circumferential direction when the switching member 62 is rotated to open or close the first opening / closing valve 61.

[0043] An engagement claw 62f is formed on the upper end of the switching member 62. The engagement claw 62f engages with an engaged portion 40c (see FIG. 9) in the common flow path 40, thereby preventing the switching member 62 from falling off when the recording heads 17a to 17c are removed as shown in FIG.

[0044] As shown in Fig. 12, the first opening / closing member 63 has a sliding portion 63a, a pressing portion 63b, and a small diameter portion 63c. The sliding portion 63a is substantially cylindrical, and is inserted into the insertion hole 62a of the switching member 62 so as to be slidable in the vertical direction. An engagement groove 63d is formed on the outer surface of the sliding portion 63a. The engagement groove 63d is formed so as to be inclined with respect to the axial direction (vertical direction) of the sliding portion 63a, and engages with an engagement boss 62b (see Fig. 11) of the switching member 62.

[0045] The pressing portion 63b is provided at the lower end of the first opening / closing member 63, and contacts a tip portion 68a (see FIG. 14) of the second opening / closing member 68. The small diameter portion 63c is formed between the sliding portion 63a and the pressing portion 63b, and a third O-ring 80c (see FIG. 9, first sealing member) is attached thereto, which contacts the inner surface of the insertion hole 62a of the switching member 62 when the first opening / closing valve 61 is closed.

[0046] As shown in Fig. 13, the connecting member 65 has a hollow cylindrical main body 65a with open upper and lower ends, and a support plate 65b fixed in the vicinity of the upper end of the main body 65a in a horizontal direction perpendicular to the axial direction. The upper end of the main body 65a is connected to the first on-off valve 61 (see Fig. 9). The lower end of the main body 65a is connected to the ink supply port 70 (see Fig. 9) of the recording head 17b.

[0047] A liquid passage port 65c is formed near the upper end of the main body portion 65a. A second opening / closing valve 67 (see FIG. 9) is disposed inside the main body portion 65a. The second opening / closing valve 67 has a second opening / closing member 68 and a coil spring 69 that urges the second opening / closing member 68 upward. The liquid passage port 65c has an inner diameter smaller than other parts of the main body portion 65a, and the second opening / closing member 68 is pressed against the second opening / closing member 68 by the urging force of the coil spring 69, thereby closing the ink flow path in the connecting member 65. A fourth O-ring 80d (see FIG. 9, second sealing member) that contacts the periphery of the liquid passage port 65c is attached to the second opening / closing member 68.

[0048] A tip portion 68a of the second opening / closing member 68 protrudes upward from the liquid passage port 65c of the connecting member 65 and contacts the pressing portion 63b of the first opening / closing member 63. A lower end portion of the coil spring 69 is fixed to a spring receiving portion 70a formed in an ink supply port 70 of the recording head 17b. A fifth O-ring 80e (see FIG. 9) that seals the gap between the connecting member 65 and the ink supply port 70 is attached to the ink supply port 70.

[0049] Three screw holes 65d are formed in the upper surface of the main body 65a, into which the first fixing screws 55 are fastened. By fastening the first fixing screws 55 to the screw holes 65d, the connecting member 65 is fixed in a position (connected position) where it is connected to the first on-off valve 61, as shown in FIG.

[0050] A liquid storage portion 73 is formed between the upper surface of the main body portion 65a and the liquid passage port 65c. As shown in Fig. 9, the liquid storage portion 73 has a larger diameter than the portion below the liquid passage port 65c, and has a volume equal to or greater than the space between the first on-off valve 61 and the second on-off valve 67. A protrusion 71 is formed on the side end portion of the support plate 65b. The protrusion 71 protrudes to the outside from an opening 53a (see Fig. 16) formed in the heat sink 53.

[0051] Next, a description will be given of the opening and closing operations of the first on-off valve 61 and the second on-off valve 67. Figures 14 and 15 are side cross-sectional views of the joint mechanism 60a, showing the first on-off valve 61 and the second on-off valve 67 in a closed state and an open state, respectively.

[0052] In the state shown in Figure 14, the engagement boss 62b of the switching member 62 is located at the lower end of the engagement groove 63d of the first opening / closing member 63, and the third O-ring 80c attached to the first opening / closing member 63 is pressed against the inner wall surface of the insertion hole 62a of the switching member 62, so that the first opening / closing valve 61 is in a closed state.

[0053] 14 in which the first opening / closing valve 61 is closed, the second opening / closing member 68 is pushed upward by the biasing force of the coil spring 69. As a result, the fourth O-ring 80d attached to the second opening / closing member 68 is pressed against the periphery of the fluid passage port 65c, and the second opening / closing valve 67 is in the closed state.

[0054] When opening the first on-off valve 61, from the state shown in FIG. 14, the lever portion 62e of the switching member 62 is pressed in the circumferential direction with the tip of a screwdriver or the like to rotate the switching member 62 in a predetermined direction (clockwise direction in FIG. 11). As a result, the engagement boss 62b of the switching member 62 moves from the lower end to the upper end within the engagement groove 63d of the first opening / closing member 63. Since the switching member 62 is fixed to the common flow path 40, the movement of the engagement boss 62b moves the first opening / closing member 63 downward. As a result, as shown in FIG. 15, the third O-ring 80c attached to the first opening / closing member 63 moves away from the inner wall surface of the insertion hole 62a of the switching member 62, and the first on-off valve 61 is opened.

[0055] In addition, as the first opening / closing member 63 moves downward, the second opening / closing member 68 in contact with the pressing portion 63b of the first opening / closing member 63 is pressed downward. This causes the second opening / closing member 68 to move downward in the movement direction against the biasing force of the coil spring 69. As a result, as shown in Fig. 15, the fourth O-ring 80d attached to the second opening / closing member 68 moves away from the peripheral portion of the fluid passage port 65c of the connecting member 65, and the second opening / closing valve 67 also opens.

[0056] According to the above configuration, the second on-off valve 67 arranged on the connecting member 65 side (recording heads 17a to 17c side) opens and closes following the opening and closing operation of the first on-off valve 61 arranged on the common flow path 40 side. That is, the first on-off valve 61 arranged on the common flow path 40 side and the second on-off valve 67 arranged on the connecting member 65 side (recording heads 17a to 17c side) can be opened and closed simultaneously with one operation. Therefore, there is less possibility of forgetting to close the first on-off valve 61 or the second on-off valve 67 when removing the recording heads 17a to 17c from the head unit 51, or forgetting to open the first on-off valve 61 or the second on-off valve 67 when mounting the recording heads 17a to 17c on the head unit 51.

[0057] This makes it possible to prevent ink leakage or cleaning liquid leakage caused by replacing the recording heads 17a to 17c without closing the first on-off valve 61 or the second on-off valve 67. It also makes it possible to prevent printing defects caused by forgetting to open the first on-off valve 61 or the second on-off valve 67 after replacing the recording heads 17a to 17c.

[0058] Here, when the first on-off valve 61 and the second on-off valve 67 are closed, ink or cleaning liquid remains in the space between the first on-off valve 61 and the second on-off valve 67 (the space from the insertion hole 62a of the switching member 62 to the liquid passage port 65c of the connecting member 65). Therefore, even if the recording heads 17a to 17c are removed from the common flow path 40 with the first on-off valve 61 and the second on-off valve 67 closed, there is a risk that the ink or cleaning liquid remaining between the first on-off valve 61 and the second on-off valve 67 will leak out.

[0059] Therefore, in this embodiment, a liquid storage section 73 having a volume equal to or greater than the space between the first on-off valve 61 and the second on-off valve 67 is formed on the upper surface of the connecting member 65 that constitutes the joint mechanisms 60a to 60c. As a result, when the recording heads 17a to 17c are removed from the common flow path 40, the ink or cleaning liquid remaining between the first on-off valve 61 and the second on-off valve 67 is stored in the liquid storage section 73, making it possible to suppress contamination inside the printer 100 due to leakage of ink or cleaning liquid.

[0060] 3. How to install and remove the recording head Next, the procedure for attaching and detaching the recording heads 17a to 17c will be described. Fig. 16 is an enlarged view of the vicinity of the joint mechanism 60a on the side of the recording head 17b. Here, the procedure for attaching and detaching the recording head 17b will be described, but the same procedure applies to the recording heads 17a and 17c.

[0061] When removing the recording head 17b from the common flow path 40, first, the lever portion 62e of the switching member 62 is operated to close the first on-off valve 61 and the second on-off valve 67 as shown in FIG. 14. Next, the nine first fixing screws 55 fastened to the three joint mechanisms 60a to 60c at three locations are removed. By removing the first fixing screws 55, the fastening between the connecting member 65 and the common flow path 40 is released, so that the connecting member 65 is held in the connected position only by the biasing force of the coil spring 69. The recording head 17b is fastened to the common flow path 40 by the second fixing screws 57.

[0062] Next, the protrusion 71 of the support plate 65b protruding from the opening 53a of the heat sink 53 is pressed down with a finger. As a result, the main body 65a to which the support plate 65b is fixed is also pressed down together with the support plate 65b against the biasing force of the coil spring 69. That is, the connecting member 65 moves from the connecting position to a position retracted downward (retracted position).

[0063] Fig. 17 is a diagram showing a state in which the connecting member 65 has been moved to the retracted position from the state in Fig. 16. Fig. 18 is an enlarged perspective view of a gap portion between the first on-off valve 61 and the connecting member 65 in Fig. 17. As shown in Figs. 17 and 18, a gap D is formed between the first on-off valve 61 and the connecting member 65 as the connecting member 65 moves to the retracted position.

[0064] By inserting paper or cloth into this gap D, it is possible to absorb the ink or cleaning liquid remaining between the first on-off valve 61 and the connecting member 65. Any ink or cleaning liquid that cannot be absorbed by the paper or cloth is stored in the liquid storage section 73. Thereafter, the second fixing screws 57 fastened to the left and right sides of the recording head 17b are removed, and the recording head 17b is removed from the common flow path 40.

[0065] When attaching the recording head 17b to the common flow path 40, the first on-off valves 61 of the three joint mechanisms 60a to 60c are closed, and the connecting members 65 are connected to the first on-off valves 61, respectively. Then, the first fixing screws 55 and the second fixing screws 57 are fastened to attach the recording head 17b to the common flow path 40. Thereafter, the lever portions 62e of the switching members 62 of the joint mechanisms 60a to 60c are operated to open the first on-off valves 61 and the second on-off valves 67, enabling the supply of ink and cleaning liquid to the recording head 17b.

[0066] By attaching and detaching the recording heads 17a to 17c in the above-described procedure, leakage of ink and cleaning liquid from the joint mechanisms 60a to 60c can be effectively prevented with a simple structure and operation.

[0067] In addition, the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. For example, in the above embodiment, a configuration in which three recording heads 17a to 17c are attached to one head unit 51 has been described, but, for example, a configuration in which only one recording head is attached to the head unit 51, or a configuration in which two or four or more recording heads are attached may also be used.

[0068] In addition, in the above embodiment, each of the recording heads 17a to 17c is equipped with joint mechanisms 60a, 60b for supplying ink and joint mechanism 60c for supplying cleaning liquid, but the number and arrangement of the joint mechanisms can be changed as appropriate depending on the configuration of the recording heads, etc.

[0069] In addition, in the above embodiment, an example was described in which a color printer that records color images using four colors of ink was used as the inkjet recording device, but the ink discharge path of this embodiment can also be used in the case of a monochrome printer that records monochrome images using black ink. [Industrial Applicability]

[0070] The present invention can be used in inkjet recording devices such as inkjet printers that are equipped with a detachable recording head. [Explanation of symbols]

[0071] 17a~17c Recording head 18 Ink outlet (nozzle) 30 Cleaning liquid supply unit 40 Common flow path 40a Ink supply path (liquid supply path) 40b Cleaning liquid supply path (liquid supply path) 50 Liquid supply mechanism 51 Head Unit 60a~60c Joint mechanism 61 First opening and closing valve 62 Switching member 62a Insertion hole 62b Engagement boss 62e Lever part 62f Engagement claw 63 First opening and closing member 63d Engagement groove 65 Connecting member 67 Second opening and closing valve 68 Second opening / closing member 69 Coil spring (biasing member) 70 Ink supply port (liquid supply port) 71 Protrusion 73 Liquid storage section 100 Printers (inkjet recording devices)

Claims

1. a common flow path having a liquid supply path through which one or more types of liquid including ink pass; one or more recording heads detachably attached to the common flow path and having a plurality of nozzles for ejecting the ink; a joint mechanism for connecting the liquid supply path to a liquid supply port of the recording head; A head unit which is mounted on an inkjet recording apparatus and performs image recording on a recording medium, The joint mechanism includes: a first on-off valve fixed to the common flow path and configured to open and close the liquid supply path; a connecting member that connects the first on-off valve and the liquid supply port; having the connecting member is movable between a connected position where the connecting member is connected to the first on-off valve and a retracted position where the connecting member is retracted from the connecting position, and when the connecting member is disposed at the retracted position, a gap is formed between the first on-off valve and the connecting member, A first fixing screw that fixes the connecting member to the common flow path; a second fixing screw for fixing the recording head to the common flow path; having A head unit characterized in that by removing the first fixing screw while the second fixing screw is fastened, only the connecting member can be moved between the connecting position and the retracted position while the recording head is fixed to the common flow path.

2. The first opening / closing valve is a switching member having an insertion hole and an engagement boss protruding from an inner circumferential surface of the insertion hole; a first opening / closing member including a sliding portion that is inserted into the insertion hole so as to be slidable up and down, and an engagement groove that is formed so as to be inclined with respect to an axial direction of the sliding portion and that engages with the engagement boss; a first sealing member attached to the first opening / closing member and in contact with or spaced from an inner circumferential surface of the insertion hole, A head unit as described in claim 1, characterized in that the first opening / closing valve is switched between a closed state in which the first sealing member is in contact with the inner surface of the insertion hole and a closed state in which the first sealing member is spaced from the inner surface of the insertion hole by rotating the switching member and moving the first opening / closing member up and down.

3. A common flow path having a liquid supply path through which one or more types of liquid including ink pass; one or more recording heads detachably attached to the common flow path and having a plurality of nozzles for ejecting the ink; a joint mechanism for connecting the liquid supply path to a liquid supply port of the recording head; A head unit which is mounted on an inkjet recording apparatus and performs image recording on a recording medium, The joint mechanism includes: a first on-off valve fixed to the common flow path and configured to open and close the liquid supply path; a connecting member that connects the first on-off valve and the liquid supply port; having the connecting member is movable between a connected position where the connecting member is connected to the first on-off valve and a retracted position where the connecting member is retracted from the connecting position, and when the connecting member is disposed at the retracted position, a gap is formed between the first on-off valve and the connecting member, The first opening / closing valve is a switching member having an insertion hole and an engagement boss protruding from an inner circumferential surface of the insertion hole; a first opening / closing member including a sliding portion that is inserted into the insertion hole so as to be slidable up and down, and an engagement groove that is formed so as to be inclined with respect to an axial direction of the sliding portion and that engages with the engagement boss; a first sealing member attached to the first opening / closing member and in contact with or spaced from an inner circumferential surface of the insertion hole, A head unit characterized in that, by rotating the switching member and moving the first opening / closing member up and down, the first opening / closing valve is switched between a closed state in which the first sealing member is in contact with the inner surface of the insertion hole and a closed state in which the first sealing member is separated from the inner surface of the insertion hole.

4. 4. The head unit according to claim 2, wherein the joint mechanism has a second opening / closing valve provided inside the connecting member, and the second opening / closing valve opens and closes following the opening and closing operation of the first opening / closing valve.

5. The second opening / closing valve is a second opening / closing member protruding from the liquid passage opening of the connecting member and contacting the first opening / closing member; a biasing member that biases the second opening / closing member in a direction approaching the first opening / closing member; a second sealing member attached to the second opening / closing member and in contact with or spaced from a peripheral portion of the liquid passage hole; A head unit as described in claim 4, characterized in that the second opening / closing valve is switched between a closed state in which the second sealing member is in contact with the peripheral edge of the liquid passage port and a closed state in which the second sealing member is spaced from the peripheral edge of the liquid passage port by rotating the switching member and moving the first opening / closing member up and down.

6. 6. The head unit according to claim 2, wherein the switching member has a lever portion that is operated when the switching member is rotated.

7. 7. The head unit according to claim 2, wherein the switching member has an engaging claw that engages with an engaged portion of the common flow path.

8. A head unit according to any one of claims 1 to 7, a liquid supply mechanism for supplying the liquid to the head unit; An inkjet recording apparatus comprising:

Images