JP4362741B2 - Ink tank - Google Patents

Description

  The present invention relates to an ink tank that reduces the amount of remaining ink for ink taken out from an ink chamber by ink suction force acting on an ink take-out hole.

As an ink tank for an ink jet printer, an air communication hole communicating with an ink chamber, an ink extraction hole for extracting ink from the ink chamber, and an ink passage communicating with the ink chamber and the ink extraction hole are provided in the ink chamber. If the ink liquid level is above the ink outlet hole side communication port, it will act on the ink outlet hole. The ink in the ink tank is taken out by the ink suction force. However, the ink below the ink outlet hole side communication opening remains structurally in the ink tank.
Japanese Patent Laid-Open No. 2001-270131

  However, there are the following problems when the ink tank structure is configured without protruding the ink extraction hole for extracting ink into the ink chamber. Inside the protruding portion, a valve body that can block the ink take-out hole and a spring member that presses the valve body against the ink take-out port are arranged, so that the ink take-out hole part is partially from the bottom surface of the ink chamber. It becomes a shape protruding. In that case, a wasteful space is formed between the ink tank mounting member and the amount of ink to be packed in the ink tank is lost.

  On the other hand, in order to reduce the useless space between the ink tank mounting member and the ink passage, the ink passage connecting the ink chamber and the ink take-out hole must protrude into the ink chamber. Ink that could not be removed remained, and wasted ink.

  In view of such a point, the object of the present invention is to suppress the protrusion from the bottom surface of the ink take-out hole portion in order to make the ink tank compact and pack more ink with respect to the outer diameter volume, and An object of the present invention is to propose removal of residual ink in an ink chamber that reduces residual ink in the chamber.

  In order to solve the above-described problems, the present invention includes a protruding portion that protrudes into the ink chamber from the bottom of the ink chamber formed in the ink tank, and that has an ink passage outlet hole side communication port formed at the tip thereof. An ink tank, wherein a gap for sucking up ink formed between an outer surface of the protruding portion and an inner surface of the cap member covering the protruding portion is formed, and ink sucked from the bottom portion of the ink chamber is formed inside the cap member. The ink is guided from the upper portion of the ink passage to the ink passage through the communication hole side communication port.

  Here, a gap for sucking ink that extends in a direction opposite to the protruding direction of the protruding portion may be formed between the protruding portion and the cap member from the communication port formed at the tip of the protruding portion. . A large amount of ink can be sucked up by appropriately setting the width dimension of the gap. In this case, if a protrusion for forming the gap for sucking up the ink is formed on the outer surface of the protruding portion and / or the inner surface of the cap member, a gap having an appropriate width can be formed only by mounting the cap member. Can be formed.

  Further, it is desirable that this protrusion function as a positioning protrusion for the cap member with respect to the protruding portion.

  Further, the cap member may be a cup-shaped cap, and in this case, the ink sucking is performed between the opening end surface of the cup-shaped cap and the bottom surface of the ink chamber facing the opening end surface. What is necessary is just to form the communication part connected to the clearance gap. It is preferable to form a plurality of protrusions for forming the communicating portion on the opening end face of the cup-shaped cap, since the communicating portion can be automatically formed when the cup-shaped cap is attached to the protruding portion.

  In order to appropriately perform the ink sucking operation, it is desirable that the outer peripheral surface of the cup-shaped cap is separated from the inner surface of the ink chamber.

  Next, if a valve body capable of sealing the ink take-out hole and a spring member that presses the valve body against the ink take-out port are disposed inside the projecting part projecting into the ink chamber, these portions are , Can be compactly incorporated.

  The ink tank according to the present invention includes a foam in which ink is absorbed and held, a foam storage chamber in which the foam is stored, an air communication hole communicating with the foam storage chamber, and an ink from the foam storage chamber. An ink take-out hole for taking out the ink, and an ink chamber is defined between the foam storage chamber and the ink take-out hole, and the foam is formed in the ink chamber by an ink suction force acting on the ink take-out hole. It is characterized in that bubbles are introduced from the storage chamber side to prevent the bubbles from proceeding from the ink chamber to the ink take-out hole.

  In this case, the first filter partitioning the foam side communication port communicating with the foam storage chamber and the ink chamber and the takeout side communication port communicating with the ink chamber and the ink takeout hole are partitioned. The first filter is formed of a porous material through which bubbles can pass by an ink suction force acting on the ink take-out hole, and the second filter includes: What is necessary is just to form from the porous material whose pore diameter is smaller than the said 1st filter.

   Here, an ink passage that communicates the ink chamber and the ink take-out hole may be provided, and the take-out hole side communication port may be partitioned by the second filter between the ink passage and the ink chamber.

  As described above, according to the present invention, the protruding portion is formed inside the ink chamber, and the ink passage leading to the ink take-out hole is formed inside the ink chamber, so that the ink tank can be formed without increasing the outer dimension. There is an advantage.

  Furthermore, in the present invention, a gap for sucking up ink that sucks up the ink accumulated in the bottom portion of the ink chamber to the position of the second filter located above is formed. Therefore, residual ink in the ink chamber can be reduced, and ink use efficiency can be increased.

  Embodiments of an ink tank for an inkjet printer according to the present invention will be described below with reference to the drawings, using a foam type ink tank. The following embodiments are examples in which the present invention is applied to an ink tank that is detachably attached to an ink tank attachment portion of an inkjet printer. Furthermore, the present invention can be similarly applied to an ink tank previously arranged in an ink jet printer.

  1A and 1B are a plan view and a front view showing a foam-type ink tank to which the present invention is applied, and FIG. 2 is a perspective view of the ink tank as viewed from the bottom side. 3 is an exploded perspective view of the ink tank.

  The ink tank 1 of this example is used by being detachably mounted on a tank mounting portion (not shown) formed in an ink jet printer (not shown). The ink tank 1 has a bowl-shaped container body 2 having an upper opening, and a container lid 4 that seals the upper opening 3, and a foam storage portion 5 is partitioned and formed therein. A rectangular parallelepiped foam 6 is accommodated as a whole in which ink is absorbed and held.

  An ink take-out hole 7 is formed in the bottom surface of the container body 2, and a disk-like rubber packing 8 is attached to the ink take-out hole 7, and a through hole 8 a opened at the center serves as an ink take-out opening. ing. A valve 9 capable of sealing the ink outlet 8a is disposed in the ink outlet hole 7 at the back of the rubber packing 8, and this valve 9 is always pressed against the rubber packing 8 by the coil spring 10 to remove the ink. The mouth 8a is blocked.

  As will be described in detail later, the foam storage portion 5 communicates with the ink extraction hole 7 via the first filter 11 and the second filter 12. Further, the foam storage portion 5 is opened to the atmosphere through an air communication hole 13 formed in the container lid 4. When the ink absorbed and held by the foam 6 attached to the foam container 5 is sucked through the ink take-out hole 7, the air corresponding to the sucked ink is supplied from the atmosphere communication port 13 to the foam container. Go into 6.

  The atmosphere communication hole 13 of the container lid 4 is connected to a bent groove 13 a carved on the surface of the container lid, and an end 13 b of the groove 13 a extends to the vicinity of the edge of the container lid 4. When the ink tank 1 is shipped, a seal 14 is affixed to a portion of the container lid 4 where the air communication hole 13 and the groove 13a are formed. When the ink tank 1 is used, the seal 14 is cut along the cut line 14a of the seal 14. By cutting off a part 14b of the groove 13a, the end 13b of the groove 13a is exposed, and the atmosphere communication hole 13 is opened to the atmosphere.

  Further, the ink tank 1 is mounted such that the ink supply needle attached to the tank mounting portion of the ink jet printer is inserted into the ink outlet 8a (see FIG. 4B). At this time, the seal 15 attached to the portion of the ink outlet 8a on the bottom surface of the container is broken and opened at the tip of the ink supply needle.

  4A and 4B are a cross-sectional view and a partial cross-sectional view of the ink tank 1 when cut along line IV-IV in FIG. 1, and FIG. 5 is a view when cut along line VV in FIG. FIG. 6 is a cross-sectional view of the ink tank 1, and FIG. 6 is a cross-sectional view of the ink tank 1 taken along the line VI-VI in FIG.

  With reference to these drawings, the structure of the ink passage portion formed between the ink take-out hole 7 and the foam storage portion 6 will be described. A cylindrical frame 22 having a rectangular cross section extends vertically through the bottom plate portion 21 in the bottom plate portion 21 of the container body 2. A rectangular communication port 25 is formed at the upper end of the upper cylindrical frame portion 23 standing upright in the foam storage portion 6 in the cylindrical frame 22. The communication port 25 is blocked by the rectangular first filter 11.

  The lower end opening of the lower cylindrical frame portion 24 projecting vertically downward from the container bottom plate portion 21 of the cylindrical frame 22 is sealed by a frame bottom plate portion 24a formed integrally therewith, and the frame bottom plate From substantially the center of the portion 24a, a cylindrical protruding portion 26 as a whole is integrally formed so as to extend vertically upward. A central hole of the protruding portion 26 is an ink passage 27 communicating with the ink take-out hole 7, and a rubber packing 8, a valve 9 and a coil spring 10 are attached thereto, and a spring receiver 28 of the coil spring 10 is attached. The protrusion 26 is integrally formed on the inner peripheral surface.

  The protruding portion 26 extends to a position below the first filter 11 by a predetermined distance, and a circular communication port 29 formed at the upper end of the protruding portion 26 is sealed by the second filter 12. .

  As described above, in the ink tank 1 of this example, the rectangular frame cylindrical frame 22 formed integrally with the container main body bottom plate portion 21 and the inner side are integrally formed between the foam storage portion 5 and the ink take-out hole 7. An ink chamber 30 is defined by the cylindrical protruding portion 26. The ink chamber 30 communicates with the foam storage portion 5 through a communication port 25 to which the first filter 11 is attached. The ink chamber 30 communicates with the ink passage 27 through a communication port 29 to which the second filter 12 is attached, and the lower end side of the ink passage 27 is connected to the ink take-out hole 7.

As described above, in the ink tank 1 of this example, the rectangular frame cylindrical frame 22 formed integrally with the container main body bottom plate portion 21 and the inner side are integrally formed between the foam storage portion 5 and the ink take-out hole 7. An ink chamber 30 is defined by the cylindrical protruding portion 26. The ink chamber 30 communicates with the foam storage portion 5 through a communication port 25 to which the first filter 11 is attached. The ink chamber 30 communicates with the ink passage 27 through a communication port 29 to which the second filter 12 is attached, and the lower end side of the ink passage 27 is connected to the ink take-out hole 7. The first filter 11 of the present example is made of a porous material that allows air to pass through the ink suction force acting on the ink extraction hole 7 while allowing ink to pass through. That is, it is made of a porous material having a pore size that becomes a capillary attractive force that destroys the meniscus by the ink suction force. This 1st filter 11 is formed from the nonwoven fabric and the mesh filter, for example.

  On the other hand, the second filter 12 is formed of a porous material having a pore diameter smaller than that of the first filter 11. The second filter 12 has a hole size capable of capturing foreign matters mixed in the ink. The second filter 12 can also be formed from a nonwoven fabric or a mesh filter.

  Here, the ink suction force is based on the ink suction force acting on the ink take-out hole 7 or the suction force of the ink pump due to the ink discharge pressure of the ink jet head (not shown) to be supplied with ink.

  Next, a cup-shaped cap 31 for sucking up ink is arranged in the ink chamber 30 of this example. The cup-shaped cap 31 sucks up ink accumulated at the bottom of the ink chamber 30 to the communication port 29 to which the second filter 12 located above is attached.

  FIGS. 7A and 7B are a perspective view and a cross-sectional view showing the cup-shaped cap 31, respectively. Referring to FIGS. 4 to 7, the cup-shaped cap 31 includes a cylindrical body portion 32 and a top plate portion 33 that seals the upper end opening, and the lower end opening 34 has a circular shape. On the end face 35, a plurality of protrusions formed at predetermined angular intervals protrude vertically. In this example, four protrusions 36 having the same height are formed at intervals of 90 degrees. The inner peripheral surface of the cylindrical body portion 32 has an inner peripheral surface portion 37 on the lower end side, a tapered inner peripheral surface portion 38 that protrudes slightly inward continuously from the upper side, and a small diameter that continues to the upper side. The inner peripheral surface portion 39 of the upper end side is provided.

  The cup-shaped cap 31 having this shape is attached to the cylindrical protruding portion 26 formed in the ink chamber 30 in a capped state from above. The outer peripheral surface of the protruding portion 26 is a large-diameter outer peripheral surface portion 41 having a slightly larger lower end side portion, and an upper-end side portion is a small-diameter outer peripheral surface portion 42, and an annular step surface 43 is formed between them. Yes. As shown in FIG. 6, the small-diameter outer peripheral surface portion 42 is formed with ribs 44 protruding outward at a predetermined angular interval. In this example, four ribs 44 are formed at intervals of 90 degrees, and the protruding amounts of these ribs 44 are the same, and have a predetermined length in the vertical direction. Further, the protruding amounts of the ribs 44 are set so that they are just fitted into the upper end side outer peripheral surface portion 39 of the cup-shaped cap 31.

When the cup-shaped cap 31 is capped on the protruding portion 26, the cup-shaped cap 31 is positioned by the four ribs 44, and four inks are sucked between the inner peripheral surface of the cup-shaped cap 31 and the outer peripheral surface of the protruding portion 26. A gap 45 having an arcuate cross section is formed. In addition, the height dimension from the lower surface of the projection 36 formed on the circular end surface 35 at the lower end of the cup-shaped cap 31 to the back surface of the top plate portion 33 is set larger than the height dimension of the protruding portion 26 by a predetermined amount. . Therefore, in the capping state, a gap 46 for an ink passage having a predetermined interval is formed between the second filter 12 attached to the upper end of the protruding portion 26 and the back surface of the top plate portion 33 of the cup-shaped cap 31. The gap 46 communicates with the gap 45. Furthermore, in the capping state, between the four protrusions 36 formed at the lower end of the cup-shaped cap 31,
Four arc-shaped cross-sectional gaps 47 having a constant width are formed. The arc-shaped cross-section gap 47 communicates with the arc-shaped cross-section gap 45.

  Here, by setting the gaps 45, 46, 47 to appropriate widths, ink is sucked up from the gap 47 through the gap 45 and protrudes through the second filter 12 through the gap 46. An ink suction passage that reaches the communication port 29 at the upper end of the portion can be formed. In this case, even when the amount of ink accumulated in the ink chamber 30 decreases and the liquid level becomes lower than that of the second filter 12, the ink in the ink chamber is sucked up to the position of the second filter 12. Thus, the ink can be supplied from the ink passage 27 to the ink extraction hole 7.

  In this example, the outer peripheral surface 32 a of the cup-shaped cap 31 is separated from the inner side surface 22 a of the cylindrical frame 22 forming the ink chamber 30 by a predetermined width. When the outer peripheral surface 32a of the cup-shaped cap 31 comes into contact with the inner side surface 22a of the cylindrical frame 22, the inside of the ink chamber is divided into right and left at the contact position, and the ink accumulated in the ink chamber can be efficiently sucked up. There is a risk that it will not be possible. In this example, the ink accumulated in the ink chamber can be efficiently sucked up by the cup-shaped cap 31.

  Next, when the ink cartridge 11 is mounted on the tank mounting portion of the ink jet printer, as shown in FIG. 4B, the tip of the ink supply needle 61 disposed on the ink jet printer side is moved to the ink in the ink tank 1. The valve 9 located in the ink passage 27 is pushed up through the through-hole 8a of the rubber packing 8 attached to the take-out hole 7.

As a result, since the ink take-out hole 7 is opened, the ink absorbed and held in the foam 6 in the foam container 5 of the ink tank 1 passes through the first filter 11 and the ink chamber 30 to the ink passage. 27, the ink can be supplied to the ink jet head on the ink jet printer side through the ink supply needle 61. Since such an ink supply mechanism is known, further description is omitted.
Next, when the ink jet head is driven and ink is ejected, ink suction force acts on the ink take-out hole 7 by the ink ejecting pressure, and ink is supplied toward the ink jet head. When ink is supplied and the ink retained in the foam 6 is reduced, air enters the foam storage portion 5 through the air communication port 13 accordingly. As indicated by the alternate long and short dash line in FIG. 4A, the ink impregnated in the foam 6 gradually decreases as the ink is consumed, and bubbles instead enter the foam 6. When the remaining amount of ink in the foam 6 decreases, air bubbles enter the ink chamber 30 through the first filter 11. Here, the second filter 12 partitioning between the ink chamber 30 and the ink take-out hole 7 does not pass bubbles. Therefore, bubbles gradually accumulate inside the ink chamber 30.

  When the remaining amount of ink further decreases, the liquid level of the ink stored in the foam container 5 and the ink chamber 30 gradually decreases. In the present invention, using the cup-shaped cap 31, an ink sucking mechanism for sucking up the ink accumulated in the bottom portion of the ink chamber 30 to the position of the second filter 12 is formed. Since substantially all of the ink accumulated in the ink chamber 30 is sucked up and supplied to the ink jet head from the ink takeout hole 7, the ink can be taken out until the ink is substantially exhausted in the ink chamber 30.

  As described above, in the ink tank 1 of this example, the gap for sucking up ink from the bottom surface portion of the ink chamber 30 to the second filter 12 is formed by using the cup-shaped cap 31. is doing. Since such a gap for sucking up ink is formed, the amount of remaining ink in the ink chamber 30 can be reduced, and ink utilization efficiency can be improved.

  In the above embodiment, since the capillary force of the ink absorber is not used, a large amount of ink can be sucked up, and it is possible to avoid running out of ink when ink is sucked. In addition, it is possible to suppress variations in the amount of ink sucked up due to fluctuations in the amount of ink supplied to the ink jet head (flow velocity) and negative pressure conditions in the ink tank. Further, in this example, the ink passage 27 that communicates with the ink take-out hole 7 is projected inside the ink chamber 30 so that the components for detecting the ink end in which these are formed are made compact. There is an advantage that an increase in installation space can be suppressed. In addition, since the ink passage 27 is provided with the valve 9 and the coil spring 10 that block the ink take-out hole 7, the ink take-out portion can be made compact.

  Furthermore, the ink tank structure of the present example is an ink tank mounted on an ink jet printer, but the head unit integrated with the head may also be integrated with the ink jet printer. Applicable.

  Further, in this example, the second filter 12 is provided. However, the first tank is disposed even when the ink tank is disposed at a position lower than the position of the ink jet head or when bubbles enter the ink chamber 127. When the meniscus of the filter 11 is restored by a slight amount of ink in the foam, the second filter 12 can be omitted.

  Further, if the bottom portion is formed by further digging only the periphery of the lower end of the cup-shaped cap 31 from the frame bottom plate portion 24a, the residual ink left in the bottom portion of the ink chamber can be further reduced.

(A) And (b) is the top view and front view which show the ink tank to which this invention is applied. FIG. 2 is a perspective view when the ink tank of FIG. 1 is viewed from the bottom side. FIG. 2 is an exploded perspective view of the ink tank of FIG. 1. (A) is sectional drawing of the ink tank at the time of cut | disconnecting by the IV-IV line | wire of FIG. 1, (b) is a fragmentary sectional view which shows the state in which the ink supply needle | hook was inserted. FIG. 5 is a cross-sectional view of the ink tank when cut along line VV in FIG. 1. It is sectional drawing of the ink tank at the time of cut | disconnecting by the VI-VI line of FIG. (A) And (b) is the perspective view and sectional drawing which show the cup-shaped cap arrange | positioned in the ink chamber of the ink tank of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ink tank 2 Container main body 3 Upper opening of container main body 4 Container lid 5 Foam storage part 6 Foam 7 Ink extraction hole 8 Rubber packing 9 Valve 10 Coil spring 11 First filter 12 Second filter 13 Atmospheric communication hole 21 Container main body Bottom plate portion 27 ink passage 30 ink chamber 31 cup-shaped cap 32 trunk portion 33 top plate portion 36 protrusion 44 rib 45 gap for sucking ink 46 communicating portion 47 gap 61 ink supply needle

Claims (7)

An ink tank provided with a projecting portion that protrudes from the bottom of the ink chamber formed in the ink tank into the ink chamber, and at the tip thereof is formed with a communication hole side communication port of the ink passage,
Forming a gap for sucking up ink formed by the outer surface of the protruding portion and the inner surface of the cap member covering the protruding portion;
An ink tank, wherein ink sucked from a bottom portion of the ink chamber is guided to the ink passage from an upper part inside the cap member through the outlet hole side communication port. In claim 1,
An ink tank, wherein a protrusion for dividing the ink suction gap into a plurality of portions is formed on an outer surface of the protruding portion and / or an inner surface of the cap member. In claim 2,
The ink tank according to claim 1, wherein the protrusion is a positioning protrusion of the cap member. In claim 1,
The cap member is a cup-shaped cap, and a communication portion communicating with the ink suction gap is provided between the opening end surface of the cup-shaped cap and the bottom surface of the ink chamber facing the opening end surface. An ink tank characterized by being formed. In claim 4,
An ink tank, wherein an opening end surface of the cup-shaped cap includes a plurality of protrusions for forming the communication portion.   6. The ink tank according to claim 4, wherein an outer peripheral surface of the cup-shaped cap is separated from an inner surface of the ink chamber. In claim 1,
An ink tank comprising: a valve body capable of sealing the ink take-out hole; and a spring member pressing the valve body against the ink take-out hole.

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