JP4552505B2 - Inkjet printer - Google Patents

Description

  The present invention relates to an ink jet printer, and more particularly to an ink jet printer capable of separating and retaining bubbles separated in an ink flow path and discharging the bubbles to the outside.

  In order to ensure thinness as a product, there is a demand for reducing the thickness of the carriage, that is, for a configuration in which the ink tank is not mounted on the carriage. In order to satisfy such a requirement, it is necessary to provide an ink tank outside the carriage, for example, in a printer frame, and supply the ink in the ink tank to the recording head on the carriage via an ink supply tube.

  In an ink jet printer using such an ink supply tube, it is inevitable that air permeates through the tube and dissolves in the ink due to the characteristics of the material constituting the tube. Therefore, a so-called exhaust purge is required in which a bubble storage chamber is provided on the upstream side of the recording head, and the bubbles are separated from the ink in the bubble storage chamber to remove the bubbles.

  As a technique for removing bubbles in an ink jet printer using an ink supply tube, a manifold (corresponding to a bubble storage chamber) is provided above the recording head, an ink tank and a circulation pump are provided on the stationary position side, and this circulation pump is driven. What was comprised so that a bubble might be removed is known (for example, refer patent document 1).

  The technique described in Patent Document 1 requires a return tube from the circulation pump to the ink tank in order to circulate the ink, and there is a problem that the apparatus becomes large and complicated.

  In addition, there is also known a method in which air separated as bubbles in the ink supply tube is accumulated in an upper part of a tank mounted on the carriage, discharged by an exhaust pump, and after discharge, the tank is sealed by an exhaust valve (for example, Patent Document 2).

  The inventor of the present invention has conducted research to satisfy the demand for making the exhaust valve structure as simple as possible in such an ink jet printer, and as a result, in the passage hole which is a part of the exhaust passage communicating with the bubble storage chamber, By providing a valve body along the axial direction of the passage hole and displacing the valve body with the operation member, the bubbles in the bubble storage chamber can be easily discharged by connecting or blocking the exhaust passage. We have developed an exhaust valve means that makes this possible.

  In such an exhaust valve means, when the bubbles are removed, for example, it is necessary to displace the valve body along the axial direction of the passage hole at a maintenance position outside the recording area where the recording head performs recording.

Therefore, at the maintenance position, in order to perform the exhaust purge by capping the opening end of the passage hole with the cap member, the cap member is provided with an operation member having an operation portion for moving the valve body, and simultaneously with the capping operation. It is conceivable to move the valve body by the operating member to open the exhaust valve means.
JP 2000-103084 A (see paragraphs 0026 to 0031 and FIG. 1) Japanese Patent Laid-Open No. 2002-240310 (see paragraphs 0006 to 0018 and FIG. 5)

  In that case, it is necessary to position and insert the operation portion of the operation member provided at the maintenance position where the carriage has moved from the opening end of the passage hole, but this is difficult. That is, stopping the carriage moving from the recording area so that the positional relationship between the opening end of the passage hole and the operating portion of the operating member coincides with each other requires high stopping accuracy.

  The present invention provides an ink jet printer in which the exhaust valve means can be reliably opened by the operation member even if the carriage does not stop with high stop accuracy.

According to a first aspect of the present invention, there is provided a recording head for recording on a recording medium by ejecting ink from a plurality of nozzle groups onto a carriage that scans along the recording medium, and a plurality of ink tanks provided outside the carriage. A buffer tank having a storage chamber for storing the ink supplied from the ink and separating the air from the ink; an exhaust passage provided for exhausting the air separated in the storage chamber to the outside; and the exhaust passage to the outside And an exhaust valve means provided for opening and closing, and an ink jet printer provided with a valve opening and closing means for opening and closing the exhaust valve means outside the carriage, wherein the exhaust valve means and the valve opening and closing means include: When the valve opening / closing means opens / closes the exhaust valve means, the valve opening / closing means is positioned side by side in a direction intersecting the carriage scanning direction, and the valve opening / closing means Furthermore, the valve opening / closing means is positioned so as to be interposed between the exhaust valve means and the valve opening / closing means in the intersecting direction when the valve opening / closing means opens / closes the exhaust valve means. An operation member is provided, and the length of the operation member is longer than the length of the exhaust valve means and the length of the valve opening / closing means in the carriage scanning direction .
In this way, when the carriage moves to a predetermined position, it faces the surface of the operation member having a length larger than the length of the valve opening / closing means in the carriage scanning direction, so that the position accuracy when the carriage stops is stopped. Even if it is low, the exhaust valve means can be reliably operated through the operation member by the valve opening / closing means.
According to a second aspect of the present invention, in the ink jet printer according to the first aspect, the buffer tank has a plurality of the storage chambers for each type of ink, and a plurality of the exhaust passages are provided for the respective storage chambers. A plurality of exhaust valve means are provided for each of the exhaust passages, the exhaust passages extend in parallel with each other, and each of the exhaust valve means has a valve body movable in the direction in which the exhaust passage extends. And the operation member faces at least two of the valve bodies and is operable in a direction in which the exhaust passage extends, and the operation member pushes and releases the valve body by operation in that direction. When the carriage moves to a predetermined position, the operation member is operated by the valve opening / closing means to operate the at least two exhaust valve means simultaneously.

  In this case, since the operation member is operably provided on the carriage, the carriage and the operation member can move together at any time, and the operation member can operate regardless of the position of the carriage. It is. Then, when the carriage is moved to a predetermined position (for example, a standby position or a maintenance position at the side of the printing area where printing is not performed), at least two operation members are operated by the valve opening / closing means. By operating the exhaust valve means simultaneously, the exhaust valve means can be reliably opened.

In other words, the operating member is provided on the carriage side, and the exhaust valve means is opened simply by operating the operating member by the valve opening / closing means. Therefore, when the carriage moves to a predetermined position, the stop when the carriage stops. There is no problem even if the position accuracy is low.
Further, since the operation portion of the operation member faces the valve body and can operate in the direction in which the exhaust passage extends (exhaust passage direction), the operation portion pushes the valve body by the operation of the operation portion in that direction, The exhaust valve means is opened. The exhaust valve means can be opened and closed with a simple structure by a combination of a valve body movable in the exhaust passage direction and an operation member that pushes the valve body by operation in the exhaust passage direction.
A specific configuration of the operating member capable of simultaneously opening the valve body can be configured as in claim 3. That is, according to a third aspect of the present invention, in the ink jet printer according to the second aspect, the operation member is provided with a base portion facing the plurality of valve bodies, and is erected on the base portion so as to be in contact with the plurality of valve bodies. A plurality of operation portions, and the plurality of operation portions are configured to have the same height from the base portion in a direction in which the exhaust passage extends.

According to a fourth aspect of the present invention, in the ink jet printer according to the second or third aspect , the casing of the exhaust valve means has a recess that allows the open ends of the at least two exhaust passages to communicate with each other. Is configured to be operably accommodated in the recess.

  In this way, since the recess is provided in the casing of the exhaust valve means and the operation member is operably accommodated in the recess, the operation member can be provided on the carriage without difficulty.

According to a fifth aspect of the present invention, in the ink jet printer according to the fourth aspect, the concave portion is provided side by side with a surface where the nozzle of the recording head is opened, and one surface of the operation member exposed from the concave portion is the recording head. It is set as the structure which exists on the substantially same surface as the surface where the nozzle of this opens.

  In this way, since one surface of the operation member exposed from the recess is substantially on the same surface as the surface where the nozzles of the recording head are opened, there is no problem of interference with the recording medium when the carriage is moved.

According to a sixth aspect of the present invention, in the ink jet printer according to any one of the second to fifth aspects, the operation member is operable in a direction in which the exhaust passage extends in a guide hole formed in a casing of the exhaust valve means. It is set as the structure which has an engaging part engaged with.

  In this way, when the operating member moves in the direction of the exhaust passage, the operating member is guided by the engagement relationship between the guide hole of the casing of the exhaust valve means and the engaging portion of the operating member. During this process, the operating member is not inclined and the amount of movement of the valve body for opening the exhaust valve means is not insufficient.

A seventh aspect of the present invention is the ink jet printer according to any one of the first to fifth aspects, wherein the operation member has a surface on the side facing the valve opening / closing means scanned on the carriage rather than the opening end of the exhaust passage. The configuration is set to be large in the direction.

  In this way, when the carriage moves to a predetermined position, the valve opening / closing means faces the surface of the operating member that is larger in the carriage scanning direction than the exhaust passage, so that the positional accuracy when the carriage stops is low. In addition, the exhaust valve means can be reliably operated by the valve opening / closing means.

The invention according to claim 8 is the ink jet printer according to claim 1 , wherein the operation member is provided on the carriage so as to be operable in an opening / closing direction of the exhaust valve means, and when the carriage moves to a predetermined position, The valve opening / closing means faces the operation member, and the exhaust valve means is operated by the valve opening / closing means via the operation member. Here, “the operation member is operably provided on the carriage” means (i) the operation member is provided on the carriage.
It means that it moves together with the carriage, and (ii) that the operating member is in an operable state at any time (a state in which the exhaust valve means can be operated simultaneously).

    According to this configuration, since the operation member is operably provided on the carriage, the exhaust valve means is reliably operated by operating the operation member by the valve opening means when the carriage moves to a predetermined position. be able to.

The invention according to claim 9 is the ink jet printer according to claim 1 , wherein the operation member is connected to an end of the valve opening / closing means on the exhaust valve means side, and the carriage moves to a predetermined position. The valve opening / closing means faces the exhaust valve means via the operation member, and the exhaust valve means is operated via the operation member by the valve opening / closing means.

    In this way, since the operating member is connected to the end of the valve opening / closing means on the exhaust valve means side, when the carriage moves to a predetermined position, the exhaust valve means is opened via the operating member by the valve opening means. Can be operated reliably.

According to a tenth aspect of the present invention, in the ink jet printer according to the first, eighth, or ninth aspect, the buffer tank has a plurality of the storage chambers for each type of ink, and a plurality of the exhaust passages for each of the storage chambers. And a plurality of the exhaust valve means are provided for each of the exhaust passages, and the operation member is positioned to face at least two exhaust valve means among the plurality of exhaust valve means.

    In this way, in an ink jet printer using a plurality of types of ink (for example, an ink jet printer capable of multicolor recording), a storage chamber, an exhaust passage, and an exhaust valve means are provided for each type of ink. The air can be discharged without causing Further, since the operation member is positioned to face at least two exhaust valve means, the configuration of the valve opening / closing means for operating the exhaust valve means can be simplified.

  According to an eleventh aspect of the present invention, in the ink jet printer according to any one of the first to tenth aspects, an exhaust unit that is connectable to the exhaust passage when the carriage moves to the predetermined position outside the carriage. It is set as the structure provided with.

    In this way, when the carriage moves to a predetermined position, the exhaust valve means can be operated by the operating member as described above, and the air can be discharged by the exhaust means connected to the exhaust passage.

  As described above, according to the present invention, when the carriage moves to a predetermined position, the exhaust valve means can be reliably opened only by operating the operation member by the valve opening / closing means.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic configuration diagram showing main components of an ink jet printer according to the present invention, FIG. 2 is a bottom view of the ink jet printer head, and FIG. 3 is an exploded perspective view of a recording head, a reinforcing frame, a carriage, and a buffer tank.

  As shown in FIG. 1 to FIG. 3, an ink jet printer 100 is an ink jet printer head 1 that has an ink jet type and a thin plate shape that ejects ink from a plurality of nozzle groups to perform recording on a paper P (recording medium). A recording head 11 and a carriage 12 mounted with the recording head 11 and formed of a synthetic resin material are provided, and the carriage 12 moves relative to the paper P. The ink is supplied from a plurality of ink tanks (not shown) provided outside the carriage 12 to the buffer tank 14 mounted on the carriage 12 via the ink supply tubes 13a to 13d (ink flow paths). The ink is temporarily stored and then supplied to the recording head 11 through the buffer tank 14. The plurality of ink tanks are detachably mounted on a printer frame (not shown), and store a large amount of ink supplied to the recording head 11. Although not specifically shown, a plurality of ink tanks (individual colors, that is, ink tanks for black, cyan, magenta, and yellow) are provided in the printer frame for full-color recording.

  The carriage 12 is slidably supported by a rear guide member 2A and a front guide member 2B which are provided in parallel in the front and rear of the printer frame and extend in the left-right direction of the frame. The rear guide member 2A has a substantially L-shaped cross section orthogonal to the slide movement direction, and the front guide member 2B has a horizontal surface extending in the slide movement direction. A part of the endless timing belt 4 wound between the driving pulley 3A and the driven pulley 3B is connected to the carriage 12, and the driving pulley 3A is rotationally driven by the driving motor 5, thereby causing the carriage 12 to rotate. Is configured to reciprocate in the left-right direction of the frame along the guide members 2A and 2B via the timing belt 4. The upper part of the carriage 12 is covered with a cover 24. Although not specifically shown, the paper P is recorded in a direction (arrow A direction in FIG. 1) perpendicular to the scanning direction (movement direction) of the carriage 12 on the lower surface side of the recording head 11 by a known paper transport mechanism. It is transported as possible. In the printer frame, a maintenance unit 70 described later (the nozzle surface is cleaned, a recovery process for selectively sucking ink for each color, and bubbles (air) in the buffer tank 14 are contained. In addition to performing a removal process to remove, an ink receiving portion (injecting (flushing) ink periodically to prevent nozzle clogging during a recording operation) is provided.

  On the lower surface of the recording head 11, two rows of black ink (BK) nozzles 16 a and a row of cyan ink (C) nozzles 16 b from the left side in FIG. 2 (view of the recording head 11 viewed from the lower surface), A row of nozzles 16 c for yellow ink (Y) and a row of nozzles 16 d for magenta ink (M) are formed long in a direction perpendicular to the scanning direction of the carriage 12. The nozzles 16a to 16d are exposed downward so as to face the upper surface of the paper P.

  At one end side of the recording head 11, as shown in FIG. 3, ink supply ports 18a to 18d of the cavity unit 17 are opened in rows on the upper surface and provided for each ink color (four colors in this embodiment). It has been. The ink is distributed through the ink supply channels extending from the ink supply ports 18a to 18d, and the piezoelectric actuator 19 is driven to eject the ink from the nozzles 16a to 16d. The ink supply port 18a for black ink (BK) has a larger opening area than the ink supply ports 18b to 18d for cyan ink (C), yellow ink (Y), and magenta ink (M). .

  In the recording head 11, the outer shape of the piezoelectric actuator 19 is made smaller than the outer shape of the cavity unit 17 in a plan view, and the ink supply ports 18 a to 18 d are included when the piezoelectric actuator 19 is stacked on the back surface of the cavity unit 17. The back surface of the cavity unit 17 around the piezoelectric actuator 19 is exposed on the back surface side of the recording head 11.

  A flexible flat cable 20 that applies a voltage to the actuator 19 is fixed to the upper surface of the piezoelectric actuator 19. The flexible flat cable 20 includes a driver IC 21 and is electrically connected to a printed circuit board 22 (see FIG. 5) provided on the upper side of the buffer tank 14. The printed circuit board 22 is configured to be connected to a printed circuit board (not shown) on the printer frame side via another flexible flat cable 20 '. Since the driver IC 21 generates heat, an aluminum alloy heat sink 23 is pressed against the driver IC 21 to cool it (see FIG. 6), and the driver IC 21 is naturally cooled via the heat sink 23.

  As shown in FIGS. 4 to 6, the buffer tank 14 partitions the interior of the main body case 25 with a partition wall, thereby storing a plurality of independent storage chambers for each ink color, that is, storage for black ink (BK). A chamber 31a, a cyan ink (C) storage chamber 31b, a yellow ink (Y) storage chamber 31c, and a magenta ink (M) storage chamber 31d are provided.

  The main body case 25 of the buffer tank 14 includes a box-shaped lower case 26 whose upper surface is opened, and an upper case 27 that covers the upper surface of the lower case 26 and is fixed to the lower case 26. Both the lower case 26 and the upper case 27 are injection-molded with a synthetic resin material, and are liquid-tightly joined by ultrasonic welding or the like. The storage chambers 31a to 31d are formed by combining these cases 26 and 27. Note that the storage chambers 31a to 31d include not only the case where each of the storage chambers 31a to 31d is formed of one single chamber, but also the case where each of the chambers is constituted by a plurality of divided chambers. And each storage chamber 31a-31d is connected to the ink outflow port 32a-32d for each ink color in those edge parts.

  A bottom plate 12a, which is a bottom wall of the carriage 12, is substantially parallel to the back surface of the recording head 11, and the recording head 11 is bonded to the bottom surface of the bottom plate 12a. A buffer tank 14 for temporarily storing ink and an exhaust valve means 15 for exhausting the air in the storage chambers 31a to 31d of the buffer tank 14 are mounted on the upper side of the bottom plate 12a of the carriage 12. Yes. The exhaust valve means 15 is provided for each of the storage chambers 31a to 31d.

  The ink outlets 32a to 32d are arranged side by side on the lower surface of the lower case 26, and are opened downward at a position protruding downward from the bottom plate 12a. On the other hand, the cavity unit 17 (recording head 11) has a plurality of ink supply ports 18a to 18d communicating with the end portions of the ink supply channels (manifolds) for the respective ink colors on the upper surface facing the ink outlets 32a to 32d. We are prepared for position. The ink outlets 32a to 32d of the storage chambers 31a to 31d pass through the ink passage holes 33b to 33e provided in the reinforcing frame 33, and the ink supply ports 18a to 18d of the recording head 11 and an elastic seal such as rubber packing. It communicates via the material 34.

  The recording head 11 is fixed to the lower side of the carriage 12 with a frame-shaped reinforcing frame 33 interposed on the back surface thereof. The reinforcing frame 33 has a flat thin plate shape along the back surface of the recording head 11, and the size of the central opening 33a in the reinforcing frame 33 is slightly larger than the outer shape of the piezoelectric actuator 19 in plan view, and the cavity It is formed smaller than the outer shape of the unit 17. Therefore, the reinforcing frame 33 is bonded and fixed to the back surface of the cavity unit 17 so that the piezoelectric actuator 19 and the flexible flat cable 20 are positioned in the central opening 33a.

  The reinforcing frame 33 is made of metal (for example, SUS430) and is thicker than the cavity unit 17 and has a large rigidity. The reinforcing frame 33 is located at one end side of the reinforcing frame 33 corresponding to the ink supply ports 18 a to 18 d of the cavity unit 17, and the ink outlets 32 a to 32 d of the buffer tank 14 and the ink supply ports 18 a to 18 d of the cavity unit 17. Ink passage holes 33b to 33e are formed in a row.

  In order to eliminate the level difference between the recording head 11 and the reinforcing frame 33 and protect the recording head 11, a U-shaped protective cover 51 located around the recording head 11 is attached to the reinforcing frame 33. Yes.

  In addition, screw holes 33f and 33g are provided at corners of the reinforcing frame 33. In correspondence with the screw holes 33f and 33g, flange-like attachment portions 14a projecting in the outer peripheral direction are provided on the outer peripheral surface of the buffer tank 14, and attachment holes 14b are formed in the respective attachment portions 14a. Then, the screw 28 as a fastening member is screwed into the screw holes 33f and 33g through the mounting holes 14b, whereby the buffer tank 14 is fixed to the upper surface of the reinforcing frame 33 that is bonded and fixed to the lower surface of the bottom plate 12a. .

  A flange-like tank extension 27a protrudes laterally from the side surface of the buffer tank 14 (specifically, the upper case 27 of the buffer tank 14) on the side opposite to the portion where the ink outlets 32a to 32d are provided. Yes. As shown in FIGS. 3 and 4, the tank extension 27a has an ink flow path for each ink color, that is, for black ink (BK), cyan ink (C), yellow ink (Y), and magenta ink ( M) ink flow paths 35a, 35b, 35c, and 35d are formed independently, and their downstream ends communicate with the storage chambers 31a to 31d, respectively. Below the tank extension 27a of the upper case 27, a holder extension 12b of the carriage 12 is provided corresponding to the tank extension 27a. The holder extension 12b extends from the upper end of the box-shaped carriage body 12c in which the buffer tank 14 is accommodated, corresponding to the tank extension 27a. A tube joint 36 having an ink flow path for each ink color is elastically attached by a spring 37 to the distal end portions of both extension portions 27a and 12b. As a result, the upstream ends of the ink flow paths 35 a to 35 d communicate with the ink flow paths inside the tube joint 36.

  The tube joint 36 has tube connection ports 36a to 36d communicating with the respective ink flow paths inside. The tube connection ports 36a to 36d are connected to the ink supply tubes 13a to 13d with one end communicating with the ink tank. The other end of 13d is detachably connected. The tube joint 36 is integrally provided with a locking portion 36e for locking the flexible flat cable 20 'for connecting the printed circuit board 22 and a printed circuit board (not shown) on the printer frame side.

  Further, on the upper surface side of the upper case 27, exhaust passages 41a to 41d whose one ends communicate with the upper spaces of the storage chambers 31a to 31d are respectively recessed (four) independently for each of the storage chambers 31a to 31d. Is formed. The other ends of the exhaust passages 41 a to 41 d extend across the body case 25 and communicate with the exhaust valve means 15. The exhaust passages 41 a to 41 d are defined by covering their open upper surfaces with a flexible film 43.

  Next, the exhaust valve means 15 provided for each of the exhaust passages 41a to 41d in order to open and close the exhaust passages 41a to 41d with respect to the outside will be described with reference to FIGS.

  The casing of the exhaust valve means 15 has a series of shapes with respect to the plurality of exhaust valve means 15, and covers the lower casing 26g integrally formed on one side of the lower case 26 and the upper part of the lower casing 26g. The upper casing 27h is integrally formed by extending one side of the upper case 27. Exhaust holes 42a to 42d constituting part of the exhaust passage are formed in the lower casing 26g. The exhaust holes 42a to 42d extend in parallel to each other, and the valve body 44 is provided in the exhaust holes 42a to 42d so as to be movable in the direction of the exhaust hole (exhaust passage direction), thereby forming the exhaust valve means 15. The The exhaust holes 42a to 42d are long in the vertical direction and open vertically, and are formed for each ink color (four). Each of the exhaust holes 42a to 42d has an upper large-diameter hole portion 42A and a small-diameter hole portion 42B positioned on the lower side, and these communicate with each other through the communication port 42C. The exhaust passages 41a to 41d of the upper case 27 extend to the upper casing 27h and communicate with the upper ends of the large diameter holes 42A of the exhaust holes 42a to 42d.

  The valve body 44 includes a large-diameter valve portion 44a, a small-diameter valve rod 44b integrally connected to the lower end thereof, and a ring-shaped sealing material 44c fitted (fitted) to the valve rod 44b. . The valve portion 44a has a larger diameter than the valve rod 44b, and the sealing material 44c is in contact with the valve portion 44a. The valve portion 44a faces the opening end surface 42D around the communication port 42C, which is the bottom surface of the large diameter hole portion 42A and the upper end opening portion of the small diameter hole portion 42B, through the sealing material 44c. A large-diameter valve portion 44A is inserted into the large-diameter hole portion 42A of the exhaust holes 42a to 42d, and a valve rod 44b is inserted into the small-diameter hole portion 42B leaving a gap that allows air (gas) to flow therethrough. Is done. Since the valve body 44 is pushed up by the push-up pin portion 76b (operation portion) when the valve is opened as will be described later, the lower end of the valve rod 44b extends to the vicinity of the lower end opening of the small diameter hole portion 42B. Note that rubber-like elastic packing or the like is suitable as the sealing material 44c. In this embodiment, an O-ring is used as the sealing material 44c.

  An opening end surface 42D of the communication port 42C communicating with the atmosphere serves as a valve seat surface, and a sealing material 44c is disposed between the opening end surface 42D and the valve portion 44a. Therefore, the communication port 42C is opened and closed by the valve portion 44a through the sealing material 44c.

  A coil spring 45 is fitted into the large-diameter hole portion 42A as urging means for urging the valve body 44 (valve portion 44a) in a direction to close the communication port 42C. The upper end portion of the coil spring 45 is fitted to the outside of the engaging convex portion 27b of the upper case 27, and the lower end portion is fitted into the concave portion 44aa on the upper side of the valve portion 44a. Then, the valve spring 44 (valve portion 44a) is urged by the coil spring 45 in the direction in which the sealing material 44c abuts against the opening end surface 42D, and the pushing force by the push-up pin portion 76b described later does not act on the valve body 44. The exhaust valve means 15 is in a valve closed state in which the communication port 42C is closed.

  Specifically, as shown in FIGS. 7A and 7B, the valve body 44 has a cut surface of the valve rod 44b in a direction orthogonal to the moving direction (exhaust passage direction) of the valve body 44. And five (plural) projecting surface portions 44f project radially from an intersection portion 44e formed by intersecting the axis extending in the moving direction. The outer shape of the cut surface is rotationally symmetric with respect to the intersection 44e, and the valve rod 44b includes the same number of grooves 44d as the protruding surface 44f. The groove 44d is formed over the entire length of the valve rod 44b. Here, the number of the projecting surface portions 44f is not limited to five, and may be a rotationally symmetric shape and may be plural.

  The (five) groove portions 44d formed in the valve rod 44b function as flow paths that allow air to flow between the valve rod 44b and the sealing material 44c when the valve portion 44a and the sealing material 44c are separated. To do.

  As shown in FIG. 6, the maintenance unit 70 includes a first cap member 71 that can seal the opening surfaces of the nozzles 16a to 16d of the recording head 11, and a lower end opening (that is, each small-diameter hole portion 42B) of the exhaust valve means 15. And a second cap member 72 capable of sealing the lower end opening surface thereof. These are connected together at a constant interval. Note that the cap member 72 may be configured such that the lower end opening of each exhaust valve means 15 can be individually sealed.

  Both cap members 71 and 72 are configured to move up and down by a first moving device 73A having the same structure as a known maintenance unit. A first cap member 71 that seals the nozzle surface of the recording head 11 for maintenance, and a second cap member 72 that seals the open end of the exhaust valve means 15 including the operation member 76 provided near the open end. Can be moved by one moving device 73A, and a mechanism for performing a capping operation for sealing them and a capping releasing operation for separating them is simplified.

  When the position detecting sensor 83 detects that the recording head 11 (carriage 12) has moved to a standby position where printing is not performed under the control of the control means 82, which will be described later, the moving device 73A performs recording at the standby position. The cap members 71 and 72 are raised to the first position where the nozzle surface of the head 11 and the exhaust port of the exhaust valve means 15 are sealed. On the other hand, when the recording head 11 is at another position (a position other than the standby position), the second lowering from the first position is separated from the nozzle surface of the recording head 11 and the exhaust port of the exhaust valve means 15. Lower to position.

  Further, the first cap member 71 is connected to the suction pump 74 in the same manner as a known maintenance unit, and the ink and foreign matters that are thickened from the nozzles 16a to 16d are sucked and removed by driving the suction pump 74.

  As shown in FIGS. 8 and 9, the operation member 76 for operating each exhaust valve means 15 includes a plurality of push-up pins (operation parts) 76b protruding corresponding to the small diameter holes 42B of each exhaust valve means. The exhaust valve means 15 is formed so as to protrude from a base portion 76a extending in the arrangement direction, and is provided movably (operably) in the lower casing 26g. That is, the lower casing 26g is formed with a recess 26c that allows the lower end openings of the exhaust valve means 15 to communicate with each other. The base portion 76a of the operating member 76 is accommodated in the recess 26c, and the push-up pin portion 76b is connected to each small-diameter hole portion 42B. It is inserted in the exhaust passage so as to be movable (operable). Each push-up pin portion 76b pushes the valve body 44 by the movement in the above-mentioned direction, opens the communication port 42C, and puts the exhaust valve means 15 into the valve open state. A gap is formed between the outer periphery of the base portion 76a of the operation member 76 and the inner periphery of the recess 26c, and between the outer periphery of each pin portion 76b and the inner periphery of the exhaust holes 42a to 42d. Each exhaust hole 42a-42d is open | released by the lower surface of the lower casing 26g.

  The width of the lower surface of the base portion 76a (the width in the carriage scanning direction, that is, the width shown in FIG. 6) is formed larger than the diameter of each of the exhaust holes 42a to 42d, and the length in the direction perpendicular thereto is also formed. That is, the area of the lower surface of the base portion 76a is sufficiently larger than the area of the lower end opening of each of the exhaust holes 42a to 42d, and the movable member 73a described later is configured to easily face the lower surface of the base portion 76a. If the movable member 73a is inserted into the exhaust holes 42a to 42d and directly pushes up the valve rod 44b, the carriage 12 needs to be stopped at a standby position with high accuracy. Even if the accuracy of the stop position is not so high, the movable member 73a can push up the valve rod 44b through the base portion 76a.

  The lower part of the operation member 76 (base 76a) is exposed from the recess 26c, but the exposed lower surface (one surface) is the nozzle surface (nozzles 16a to 16d) of the recording head 11 provided side by side with the recess 26c. Is substantially on the same plane as the surface of the opening. Since these surfaces are substantially on the same surface, it is easy to continuously clean (wipe) the nozzle surface and the lower surface of the operation member 76, and there is a problem of interference with the paper P when the carriage 12 moves. Does not occur.

  Further, at the center of the operation member 76, an engaging portion 76c is provided that protrudes in the same direction and in parallel with the push-up pin portion 76b. On the other hand, a guide hole 26a is provided in the lower casing 26g in parallel with the central axis of the exhaust holes 42a to 42d. The engaging portion 76c is slidably engaged with the guide hole 26a with a gap through which air can flow, and the operating portions 76a of the operating member 76 are guided in the exhaust passage direction by their engaging relationship. The large-diameter head of the engaging portion 76c abuts on the outer edge of the upper end opening of the guide hole 26a, whereby the operation member 76 is held by the lower casing 26g and the operation member 76 moves together with the carriage 12. It is supposed to be.

  At the upper end of the guide hole 26a, an atmosphere communication hole 26b communicating with the atmosphere (outside air) is formed. At the time of exhaust purging, a seal portion is provided by a closing portion 76d provided on the operation member 76 and extending further upward than the push-up pin portion 76b. The atmospheric communication hole 26b is closed through 76e (see FIG. 9).

  The operating member 76 (push-up pin portion 76b) is moved up and down by a movable member 73a of a second moving device 73B (valve opening / closing means) different from the first moving device 73A. That is, the operation member 76 is built in the lower part of the lower casing 26g and is moved up and down by the moving device 73B outside the carriage 12. The movable member 73a penetrates the bottom of the second cap member 72 and is supported so as to be vertically slidable. By pushing the substantially central portion of the operation member 76 (base portion 76a) from the lower side, the operation member 76 is moved. It is configured to move in the direction of the exhaust passage without inclining.

  Then, the recording head 11 moves to a standby position where printing is not performed, the cap members 71 and 72 are raised, the cap member 71 seals the nozzle surface of the recording head 11, and the cap member 72 surrounds the recess 26c. When closely contacting the lower surface of the lower casing 26g, that is, when the exhaust port of the exhaust valve means 15 is sealed, the valve rod 44b is pushed upward by the push-up pin portion 76b of the operation member 76 by the second moving means 73B. At this time, as shown in FIG. 9, the sealing member 44c moves together with the valve portion 44a, and the exhaust holes 42a to 42d are in a communication state, that is, the communication port 42C is opened, and the valve is in an open state. In this valve open state, bubbles in the storage chambers 31a to 31d can be exhausted to the atmosphere from the exhaust passages 41a to 41d through the exhaust holes 42a to 42d, the second cap member 72, and the suction pump 74. For example, when ink adheres between the opening end surface 42D with which the sealing material 44c contacts and the sealing material 44c, only the valve rod 44b rises when the valve is opened, and the sealing material 44c remains on the opening end surface 42D. Even if such a phenomenon occurs, exhaust is possible because the communication port 42C is opened through the groove 44d as described above. Therefore, bubbles (air) do not continue to accumulate in the storage chambers 31a to 31d, and the bubbles (air) do not move toward the recording head, so that normal printing is not hindered. Further, for the trouble such as the ink remaining around the sealing material 44c (O-ring) thickening and the exhaust valve means 15 not opening, the lower end opening of the exhaust valve means 15 is always capped at the standby position. This can be avoided. Further, it is possible to achieve both the prevention of drying and the suction by making the atmosphere communication hole 26b into a maze shape.

  The second cap member 72 is connected to the suction pump 74 through a flow path common to the first cap member 71. Then, with the exhaust port of the exhaust valve means 15 sealed, the bubbles accumulated in the storage chambers 31a to 31d can be collectively sucked and discharged to the atmosphere by driving the suction pump 74. As described above, the ink supplied from the ink tank to the recording head 11 through the ink supply tubes 13a to 13d is temporarily stored in the storage chambers 31a to 31d in the middle of the ink flow path, so that bubbles are generated from the ink. The bubbles (air) that are separated and floated and accumulated in the upper portions of the storage chambers 31a to 31d are exhausted to the outside by the suction pump 74 as described above.

  The first cap member 71 and the second cap member 72 are alternatively connected to the suction pump 74 by the switching valve 75. Maintenance is performed on the first cap member 71 and the second cap member 72 by simultaneously sealing the nozzle surface of the recording head 11 and the exhaust port of the exhaust valve means 15 by the operation of the moving device 73A. A desirable maintenance procedure is as follows. First, the air bubbles accumulated in the upper portions of the storage chambers 31 a to 31 d are discharged through the second cap member 72, and then the ink is sucked and removed from the nozzles 16 a to 16 d through the first cap member 71. Here, the bubbles are discharged from the second cap member 72 side. If the bubbles in the storage chambers 31a to 31d are discharged from the recording head 11 side only by the first cap member 71, a large amount of ink is discharged. This is because, as described above, it is possible to discharge the bubbles and recover the recording head with a small ink discharge amount.

  The maintenance not only sequentially discharges the bubbles in the storage chambers 31a to 31d and sucks the ink from the nozzles 16a to 16d, but also only sucks the ink from the nozzles 16a to 16d or discharges the bubbles from the storage chambers 31a to 31d. Can also be performed alone.

  The above-described suction / exhaust operation is controlled by the control means 82 connected to the maintenance unit 70 (first moving device 73A, second moving device 73B, suction pump 74, switching valve 75 and position detection sensor 83). . That is, when the position detection sensor 83 detects that the recording head 11 has moved to the standby position, the cap member 72 is moved (together with the cap member 71) to the first position by the first moving device 73A. At the same time, the operating member 76 is moved in the exhaust passage direction by the second moving device 73B, the valve body 44 is moved in the opening direction, and the four exhaust valve means 15 are simultaneously opened. At this time, since the push-up pin portion 76a is inserted in the lower end opening of the exhaust valve means 15 in a state where the operation member 76 is locked to the lower portion of the lower case 26, the push-up pin portion 76a is positioned and the exhaust valve is positioned. There is no need to insert it into the lower end opening of the means 15, and each exhaust valve means 15 is opened by simply pushing up the operating member 76 with the movable member 73a of the second moving device 73B. At the same time, the air communication hole 26b is also closed by the closing portion 76d.

  In this valve open state, the suction pump 74 is driven to perform a first suction / exhaust operation for exhausting the air separated in the buffer tank 14 to the outside through the exhaust passages 41a to 41d. After the end of the first suction operation, the movable member 73a is lowered, and the operation member 76 is lowered by gravity or the coil spring 45 so that each exhaust valve means 15 is closed to block communication between the buffer tank 14 and the outside. Then, a second exhaust operation is performed to exhaust the inside of the exhaust valve means 15 (specifically, the downstream side of the communication port 42C) and the inside of the recess 26c together with the atmosphere introduced from the outside through the atmosphere communication hole 26b. As a result, the ink remaining around the communication port 42C, the small-diameter hole 42B, the operation member 76, and the like is sucked together with the atmosphere. Thereafter, the switching valve 75 is switched to perform a suction operation through the nozzle surface of the recording head 11, and although not shown, a known wiping member (wiper blade) causes the nozzle surface, the lower surface of the operation member 76, and the operation member 76 thereof. The lower surface of the lower casing 26g around the lower surface is wiped away, and the ink is removed.

  When the recording head 11 is in a position other than the standby position and recording is performed normally, the exhaust valve means 15 is in a valve closed state. At this time, ink does not remain inside the exhaust valve means and around the operation member 76 as described above, so that it does not fall during recording.

  In addition to the above embodiment, the present invention can be configured as follows.

  (i) In the above embodiment, the case where the valve body 44 of the exhaust valve means 15 moves in the vertical direction has been described. However, the movement direction of the valve body is not limited to the vertical direction, and other directions other than the vertical direction It can also be.

  (ii) Instead of the suction operation of the suction pump 74, a positive pressure is applied to the ink from the ink tank side to suck and remove thickened ink and foreign matters from the nozzles 16a to 16d, and bubbles in the storage chambers 31a to 31d. Can also be discharged. Alternatively, the suction operation and the positive pressure application to the ink can be used in combination.

  (iii) It is not always necessary to provide an air communication hole in order to introduce the air from the outside during the second suction / exhaust operation. For example, as shown in FIG. 10, after the first exhaust operation, the second cap member is provided. 72 is lowered from the lower surface of the lower casing 26g to a position where the minute gap S is opened, and the second exhaust operation is performed. That is, it is also possible to adopt a configuration in which the ink remaining in the communication port 24C and the recess 26c is removed while the air is sucked through the minute interval S. The engaging portion 76c ′ of the operation member 76 ′ is provided with a through hole 76ca, and after the second cap member 72 is separated from the lower surface of the lower casing 26g and before performing the second exhaust operation. The operation member 76 ′ can be easily lowered by the atmospheric pressure acting on the upper side of the operation member 76 ′ through the through hole 76ca.

  (iv) The engaging portion of the operating member 76 is provided at the central portion of the operating member 76, and as shown in FIG. 11, engaging portions 76c '' are provided symmetrically at both ends of the operating member 76 '', and the guide hole It can also be slidably engaged with the part 26a ''. In this case, although not shown, as in the configuration shown in FIG. 8, a blocking portion 76 b that faces the atmosphere communication hole 26 b ″ is provided, and when the exhaust valve means 15 is opened, the atmosphere communication hole is closed. Further, each push-up pin portion 76b '' of the operation member 76 '' is formed to have a size that can slide along the inner periphery of the small-diameter hole portion 42B. Can move up and down without tilting. In this case, the cross-sectional shape of the push-up pin portion 76b '' is the same as the cross-sectional shape of the bubble rod 44b in order to secure an exhaust passage between each push-up pin portion 76b '' and the inner periphery of the small diameter hole portion 42B. Has a groove on the outer periphery.

  (V) It is not necessary to open and close all the exhaust valve means with one operating member. For example, as shown in FIG. 12, one operating member 76 ′ ″ has a part of exhaust means (the leftmost 3 in FIG. 12). Only one exhaust piece means), the remaining exhaust valve means (one exhaust piece means at the right end in FIG. 12) is provided with another operation member 82, and an operation member 76 '' ' The operation member 82 can be configured to be operated independently by different movable members 73a and 84, respectively. In the case of FIG. 12, the ink supply tube, the bubble storage chamber, and the exhaust passage for black ink, which consumes a large amount of ink, are set to have a smaller channel resistance than that for ink of other colors that consume less. The exhaust means are divided into two groups so that exhaust can be performed in an optimum manner corresponding to the difference in flow path resistance, and exhaust is performed separately. Here, in the cap member 72 ′, a part for sealing the part of the exhaust valve means and a part for sealing the remaining part of the exhaust valve means are partitioned by a partition wall 72 a, and any part is selectively selected by the switching valve 81. By connecting to the suction pump, exhaust can be performed individually and independently. The engaging member 76c ′ ″ is slidably engaged with the guide hole 26a ′ ″, and the operation member 76 ′ ″ is operably accommodated in the recess 26c ′ ″ of the lower casing. The point is the same as the embodiment described above. Although not shown, the operation member 82 has an engagement portion similar to the operation member 76 at both ends in the direction orthogonal to the paper surface of FIG. 12, and is slidably engaged with and supported by the guide hole portion.

  Also in this case, the width and length of the base portion 76a ′ ″ of the operation member 76 ′ ″ (width in the carriage scanning direction and length perpendicular thereto) are formed larger than the diameters of the exhaust holes 42b to 42d. Of course, the operation member 82 is also formed so that the width and length in the same direction are larger than the diameter of the exhaust hole 42a, and the movable members 73a and 84 can be operated by the operation member 76 'even if the carriage stop position accuracy is low. '', 82 is configured to be easily opposed.

  (Vi) The push-up pin portions 76b ′ ″ and 82a are not necessarily provided on the operation members 76 ′ ″ and 82. For example, as shown in FIG. 13, the bubble rod 44b is disposed more than the lower end openings of the exhaust holes 42b to 42d. The lower end of the bubble rod 44b may be pushed up on the upper surface of the base portion of the operation member 76 ′ ″, 82 by extending downward.

  (Vii) The operation members 76 '' 'and 82 are not necessarily provided on the lower casing 26g (carriage 12) side. For example, as shown in FIG. 14, the upper ends of the movable members 73a and 84 (on the exhaust valve means side). It can also be configured to be connected to the end portion. Also in this case, when the carriage is moved to the standby position, the movable members 73a and 84 face the lower end of the bubble rod 44b via the operation members 76 ′ ″ and 82, and the movable members 73a and 84 are lifted to raise the position. The exhaust valve means 15 can be opened.

It is a schematic block diagram which shows the main components of the inkjet printer which concerns on this invention. It is a bottom view of an inkjet printer head. FIG. 3 is an exploded perspective view of a recording head, a reinforcing frame, a head holder, and a buffer tank. 1 is a plan view partially showing a cross section of an inkjet printer head according to the present invention. It is sectional drawing in the VV line of FIG. It is sectional drawing in the VI-VI line of FIG. (A) (b) shows embodiment of a valve body, respectively, (a) is a partial cross section front view, (b) is a bottom view. It is sectional drawing in the VIII-VIII line of FIG. It is operation | movement explanatory drawing. It is a figure similar to FIG. 9 which shows another embodiment. It is a figure similar to FIG. 8 which shows another embodiment. It is a figure similar to FIG. 8 which shows another embodiment. It is a figure similar to FIG. 8 which shows another embodiment. It is a figure similar to FIG. 8 which shows another embodiment.

Explanation of symbols

P paper 100 Inkjet printer 11 Recording head 12 Carriage 14 Buffer tank 15 Exhaust valve means 16a-16d Nozzle 26a Guide hole 26c Recess 26g Lower casing 31a-31d Reserving chamber 41a-41d Exhaust passage 42a-42d Exhaust hole 44 Valve body 73B Moving device (Valve opening and closing means)
76 Operation member 76a Base 76b Push-up pin part (operation part)
76c engaging part

Claims (11)

A carriage that scans along the recording medium stores a recording head that performs recording on the recording medium by ejecting ink from a plurality of nozzle groups, and ink supplied from a plurality of ink tanks provided outside the carriage. And a buffer tank having a storage chamber for separating air from the ink, an exhaust passage provided for exhausting the air separated in the storage chamber to the outside, and an opening for opening and closing the exhaust passage to the outside. An inkjet printer equipped with exhaust valve means and provided with valve opening / closing means for opening / closing the exhaust valve means outside the carriage,
The exhaust valve means and the valve opening / closing means are positioned side by side in a direction intersecting the carriage scanning direction when the valve opening / closing means opens / closes the exhaust valve means, and the valve opening / closing means intersects Configured to move in the direction,
Furthermore, when the valve opening / closing means opens and closes the exhaust valve means, an operation member is provided that is positioned so as to be interposed between the exhaust valve means and the valve opening / closing means in the intersecting direction,
The length of the operation member is larger than the length of the exhaust valve means and the length of the valve opening / closing means in the carriage scanning direction . The buffer tank has a plurality of the storage chambers for each type of ink,
A plurality of the exhaust passages are provided for each of the storage chambers, and a plurality of the exhaust valve means are provided for each of the exhaust passages,
Each of the exhaust passages extends in parallel to each other, and each of the exhaust valve means has a valve body that can move in the direction in which the exhaust passage extends.
The operating member is opposed to at least two of the valve bodies and is operable in a direction in which the exhaust passage extends, and the operation member pushes and releases the valve body by an operation in the direction.
2. The ink jet printer according to claim 1, wherein when the carriage moves to a predetermined position, the operation member is operated by the valve opening / closing means, and the at least two exhaust valve means are operated simultaneously. The operating member is
A plurality of bases facing the valve bodies;
A plurality of operation portions that are erected on the base and are in contact with the plurality of valve bodies;
3. The inkjet printer according to claim 2, wherein the plurality of operation portions have the same height from the base portion in a direction in which the exhaust passage extends.   The casing of the exhaust valve means has a recess that allows the open ends of the at least two exhaust passages to communicate with each other, and the operation member is operably accommodated in the recess. Or the inkjet printer according to 3.   The concave portion is provided side by side with a surface where the nozzle of the recording head is opened, and one surface of the operation member exposed from the concave portion is substantially flush with a surface where the nozzle of the recording head opens. The inkjet printer according to claim 4.   The said operation member has an engaging part engaged with the guide hole formed in the casing of the said exhaust valve means so that operation | movement is possible in the direction where the said exhaust passage is extended. The inkjet printer described in 1.   The surface of the operation member facing the valve opening / closing means is set larger in the carriage scanning direction than the opening end of the exhaust passage. Inkjet printer. The operation member is provided on the carriage so as to be operable in an opening / closing direction of the exhaust valve means,
The valve opening / closing means faces the operation member when the carriage moves to a predetermined position, and the exhaust valve means is operated by the valve opening / closing means via the operation member. Inkjet printer. The operating member is connected to an end of the valve opening / closing means on the exhaust valve means side,
When the carriage moves to a predetermined position, the valve opening / closing means faces the exhaust valve means via the operation member, and the exhaust valve means is operated by the valve opening / closing means via the operation member. The inkjet printer according to claim 1.   The buffer tank has a plurality of storage chambers for each type of ink, a plurality of the exhaust passages are provided for each of the storage chambers, and a plurality of the exhaust valve means are provided for each of the exhaust passages. 10. The ink jet printer according to claim 1, 8 or 9, wherein the ink jet printer is positioned opposite to at least two of the plurality of exhaust valve means.   The inkjet printer according to claim 1, further comprising an exhaust unit that is connectable to the exhaust passage when the carriage moves to the predetermined position outside the carriage.

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