JP2012025031A - Ink tank and inkjet recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve such the problem that when a check valve is disposed on the connection side to the ink chamber of the joint part of an ink tank and a valve body is disposed on the ink supply port of the joint part of the ink tank, ink in the joint part is pushed out to the side of an inkjet head by the portion of the movement volume of the valve body moved when the ink supply pipe of the inkjet head is connected, so that the meniscus of the nozzle of the inkjet head is unstable and there is a possibility to cause the disturbance of the beginning of printing and ink dropping from the nozzle.SOLUTION: Such a configuration that a displacement part which can be at least displaced by the portion of a volume corresponding to the displacement volume of the valve body by the connection of the ink supply pipe is provided to the check valve is adopted, so that even when the ink supply pipe is connected and the valve body is moved, the displacement part of the check valve is displaced and the increase of pressure in the joint part can be suppressed.

Description

  The present invention relates to an ink tank and an ink jet recording apparatus, and more particularly to an ink tank and an ink jet recording apparatus in which stability related to mounting of an ink jet head and an ink tank is ensured.

  There is known an ink jet recording apparatus that includes an ink jet head, an ink supply pipe that communicates with the ink jet head and supplies ink to the ink jet head, and an ink tank that is attached to and detached from the ink supply pipe. .

  For example, in recent ink jet recording apparatuses, an ink tank having a configuration with low pressure loss at the time of ink supply that can be applied to high-speed recording is desired. As an example, there has been proposed an ink tank that includes an ink chamber that directly stores ink and in which an ink supply port is disposed in the ink chamber. An ink supply port of this type of ink tank is known to have a configuration in which a valve body is disposed at the ink supply port in order to prevent ink leakage from the ink supply port when the ink tank is not connected to the ink supply pipe. ing.

  As a valve body, there exists a structural example as shown by patent document 1. FIG. In other words, a valve body that closes the ink supply port and a spring that biases the valve body toward the ink supply port are disposed between the ink chamber and the ink supply port. Thus, the valve body and the spring are arranged, and a connecting portion is provided as a space for connecting the ink chamber and the ink supply port. The connecting portion is communicated with the ink chamber by a communicating portion. In Patent Document 1, a check valve is further disposed in the communication portion for the purpose of preventing ink leakage due to an unexpected situation, and measures against ink leakage from the ink tank are made.

JP 2007-302010 A

  However, in the configuration as disclosed in Patent Document 1, when the ink supply port and the ink supply pipe are connected, the valve body moves inward of the connecting portion. Therefore, the ink in the connecting portion corresponding to the moving volume of the valve body is pumped to the ink supply pipe. The ink pumped from the ink supply pipe reaches the nozzle of the ink jet head and causes instability of the meniscus formed on the nozzle. This instability leads to disturbance in writing and printing at the start of recording, or in the worst case, the meniscus is destroyed and ink leaks from the nozzles.

  On the other hand, in an ink tank not provided with a mechanical erroneous mounting prevention mechanism, the ink tank may be erroneously mounted. In this case, the ink in the connecting portion of the ink tank is pumped to the ink supply pipe. In this case, an ink different from the ink that should be supplied to the ink supply pipe is sent to the ink supply pipe, which causes a problem of color mixing.

  In order to solve these problems, the present inventors have a function that allows the connecting portion to allow deformation / displacement corresponding to the moving volume of the valve body when the ink supply pipe is inserted and connected to the ink supply port. Is employed in a check valve disposed in the connecting portion.

  The present invention achieves the following objects while having a configuration in which a valve body and a check valve are arranged at a connecting portion of an ink tank. First, it is possible to stabilize the meniscus of the nozzles of the inkjet head by suppressing the situation where the ink in the connecting portion corresponding to the moving volume of the valve body is pumped to the ink supply pipe when the ink supply pipe is connected. An object of the present invention is to provide an ink tank and an ink jet recording apparatus. A second object of the present invention is to provide an ink tank and an ink jet recording apparatus capable of suppressing color mixing of ink in an ink supply pipe even when erroneously mounted.

An ink tank for achieving the above-described object is provided with an ink chamber, a communication portion communicating with the ink chamber, a connection portion provided with an ink supply port, and a valve body disposed in the connection portion and closing the ink supply port. In an ink tank comprising:
The communication portion includes a check valve that allows the flow of ink from the ink chamber to the ink supply port and blocks the flow of ink from the connecting portion to the ink chamber. The valve is characterized by having a displacement portion in the central region.

An inkjet recording apparatus for achieving the above-described object includes an inkjet head including an ink supply pipe,
An ink tank comprising: an ink chamber; a communication portion communicating with the ink chamber; a connection portion provided with an ink supply port; and a valve body disposed in the connection portion and closing the ink supply port;
In an inkjet recording apparatus in which an ink tank is configured to be detachable with respect to an inkjet head,
The check valve of the ink tank is configured with a displacement portion in a central region,
An ink tank is attached to the ink jet head, and an ink supply pipe contacts the valve body of the ink tank, and the valve body is moved inward of the connecting portion, whereby a displacement portion provided in a central region of the check valve Is deformed to the ink chamber side.

  According to the above configuration, the displacement portion provided in the central region of the check valve is displaced corresponding to the volume by which the valve body of the ink tank moves inward by the insertion of the ink supply pipe, and the communication portion Increase in internal pressure can be mitigated. Thereby, when the ink tank is mounted, the meniscus of the nozzle of the ink jet head can be stabilized, the meniscus can be prevented from collapsing, and the writing printing defect can be prevented. In addition, color mixing of ink in the ink supply pipe can be suppressed even when the ink tank is erroneously attached. Furthermore, it is possible to reduce the pressure loss when the ink is led out and to support high-speed printing.

It is a perspective view showing typically the appearance of an ink tank to which the present invention is applied. It is sectional drawing in the AA of the ink tank shown by FIG. (A) is sectional drawing which expands and shows the connection part of the ink tank by which 1st Embodiment was employ | adopted. FIG. 5B is a cross-sectional view illustrating a state in which the ink tank connecting portion and the ink supply pipe in which the first embodiment is employed are mounted. FIG. 4C is a cross-sectional view illustrating a state where the ink tank connecting portion and the ink supply pipe in which the first embodiment is adopted are mounted and ink is supplied. (A) is sectional drawing which expands and shows the connection part of the ink tank by which 2nd Embodiment was employ | adopted. FIG. 6B is a cross-sectional view illustrating a state in which the ink tank connecting portion and the ink supply pipe in which the second embodiment is employed are mounted. FIG. 6C is a cross-sectional view illustrating a state in which the ink tank connecting portion and the ink supply pipe in which the second embodiment is adopted are mounted and ink is supplied.

  Embodiments to which the present invention is applied will be described below with reference to the drawings.

  1 and 2 are diagrams showing an example of the configuration of an ink tank to which the present invention is applied. FIG. 1 is a perspective view schematically showing the appearance of the ink tank. FIG. 2 is a cross-sectional view taken along line AA in FIG. FIG.

  The ink tank 1 is configured by joining a housing 2 and a lid 3, and the inside is divided into two chambers by a partition wall 6 as shown in FIG. 2. One of the two chambers is an ink chamber 11 in which ink is directly stored, and the other is an absorber storage chamber 12 in which an ink absorber 14 is stored, and ink is held by the ink absorber. An air communication hole 4 is provided in an area of the lid 3 covering the absorber housing chamber 12, and a buffer space 15 exists between the ink absorber 14 and the air communication hole 4. The ink chamber 11 and the absorber storage chamber 12 communicate with each other through a gas-liquid exchange unit 13 provided at the bottom of the ink tank. A joint portion 5 is provided at the bottom of the ink chamber 11, and an ink supply pipe 32 communicating with the ink jet head 30 is connected to the joint portion 5, whereby ink in the ink tank is ink jetted via the joint portion 5. It is supplied to the head 30.

  As shown in FIG. 2, the joint portion 5 has an ink supply port into which a communication portion 21 communicating with the ink chamber 11 is inserted at the base end and an ink supply pipe 32 communicating with the ink jet head 30 is inserted at the tip. 22 is provided. A communication portion 20 is provided between the communication portion 21 and the ink supply port 22, and a check valve 23, a spring 25, a valve body 24, and a seal body 26 are arranged in that order from the base end side. Has been.

  The ink in the ink tank 1 is consumed as follows. That is, when ink is ejected from the inkjet head 30, the ink stored in the absorber housing chamber 12 that communicates with the air communication hole 4 decreases. After the ink interface in the absorber storage chamber 12 has decreased to the height of the upper end of the opening of the gas-liquid exchange unit 13, when the ink is consumed, gas-liquid exchange is started in the gas-liquid exchange unit 13 and the ink chamber 11 Less ink is consumed.

Example 1
FIGS. 3A to 3C are cross-sectional views showing, in an enlarged manner, the joint portion 5 of the ink tank 1 adopting a configuration example of the check valve 23.

  As shown in FIG. 3A, the joint portion 5 has a communication portion 21 side in the communication portion 20 between the communication portion 21 communicating with the ink chamber 11 and the ink supply port 22 into which the ink supply pipe 32 is inserted. A check valve 23, a spring 25, a valve body 24, and a seal body 26 are arranged in this order. In a state where the ink tank 1 is not attached to the ink jet head 30, the valve body 24 is biased by the seal body 26 disposed in the ink supply port 22 by the spring 25, whereby the valve body 24 and the seal body 26 are urged. The ink supply port 22 is tightly closed and closed.

  Next, the check valve 23 will be described. The check valve 23 of this embodiment is made of an elastic body, and the central region is thinner than the outer peripheral region 23a (not shown in the drawing). As will be described later, the thin central region functions as a displacement portion 23 b that can be expanded and contracted toward the communication portion 21 when the ink supply pipe 32 is inserted into the ink supply port 22. The check valve 23 is disposed on the inner surface of the connecting portion 20 of the communication portion 21 and allows the flow of ink from the ink chamber 11 to the ink supply port 22 and blocks the flow in the opposite direction. A part thereof is fixed to the inner wall of the connecting portion 20 by welding or the like so that the above function can be achieved. As for the fixing method, a normal method such as caulking or adhesion can be applied, and it may be in a state in which elastic deformation and displacement described below can be performed with the fixing portion as a fixed immovable portion. By configuring the outer peripheral region of the check valve 23 to be thicker than the central region, the contact accuracy with the inner wall of the connecting portion 20 is improved and the reliability of the sealing performance is improved.

  FIG. 3A shows a state where the ink tank 1 is not attached to the inkjet head 30. In this state, the check valve 23 covers the communication portion 21 and shields ink communication.

  When the ink tank 1 and the ink supply pipe 32 are connected from this state, the ink supply pipe 32 is inserted into the ink supply port 22. By this operation, the valve body 24 is pushed inward of the connecting portion 20 by the ink supply pipe 32. Before the contact between the valve body 24 and the seal body 26 is released, the outer periphery of the ink supply pipe 32 is in contact with a part of the inner periphery of the seal body 26, and ink leaks from the periphery of the ink supply pipe 32. Is suppressed.

  When the ink supply pipe 32 is inserted into the ink supply port 22 and the valve body 24 moves into the connecting part 20, the pressure in the connecting part 20 starts to rise. However, the check valve 23 is configured such that the displacement portion 23b in the central region is thin, so that when the pressure increase in the connecting portion 20 is received, the check valve 23 is shown in FIG. Thus, the displacement part 23b expands and deforms toward the communication part 21 (ink chamber 11). As a result, the pressure increase in the connecting portion 20 can be suppressed, the ink in the connecting portion 20 is not pressed against the ink supply pipe 32 and moved, the meniscus of the nozzle 31 of the inkjet head 30 is broken, and ink leakage is prevented. Occurrence is suppressed. Further, since the ink in the connecting portion 20 is suppressed from being pushed out into the ink supply pipe 32 even when the ink tank is erroneously mounted, color mixing of the ink in the ink supply pipe can be suppressed.

  Here, S1 is a moving volume in which the ink supply port 22 of the ink tank 1 is attached to the ink supply pipe 32 and the valve body 24 moves inward of the connecting portion 20, and the displacement portion 23b in the central region of the check valve is the ink chamber. When the deformation volume deformed to the 11 side is S2, it is preferable that the volumes S1 and S2 are substantially equal. The ink is not substantially pushed into the ink supply pipe 32 by being substantially equal, and the meniscus of the nozzle of the ink jet head is destroyed, or the ink is mixed in the ink supply pipe 32 when erroneously mounted. Disappears. When damage due to erroneous mounting can be prevented by another method, the relationship of volume S1> S2 may be satisfied as long as the meniscus destruction of the nozzles of the inkjet head can be suppressed.

  As shown in FIG. 3C, in the state where ink is supplied as indicated by arrow I, the ink flow from the ink chamber 11 of the ink tank 1 toward the inkjet head 1 (ink supply pipe 32) is allowed. The check valve 23 opens the communication part 21 so as not to obstruct.

(Example 2)
4A to 4C are cross-sectional views showing an enlarged joint portion 5 of the ink tank 1 in which another example of the check valve 123 is adopted. Except for the configuration of the check valve, the other configuration is the same as the configuration shown in the first embodiment, and will be described with the same reference numerals.

  The check valve 123 shown in the second embodiment will be described.

  As shown in FIG. 4A, the check valve 123 of the second embodiment is a displacement portion 123b that easily expands and deforms when it receives pressure. In this example, a bellows configuration is adopted. ing. The displacement portion 123b of the check valve 123 is not limited to the bellows configuration, and the deformation volume S2 corresponding to the movement volume S1 when the ink supply pipe 32 is inserted into the ink supply port 22 and the valve body 24 is moved. Any configuration that can deform the minute is included in the configuration of the displacement portion 123b of the present invention.

  FIG. 4A shows a state where the ink tank 1 is not attached to the inkjet head 30. In this state, the check valve 123 covers the communication portion 21 and shields ink communication. In this state, the displacement portion 123b of the check valve 123 is not expanded and deformed.

  When the ink tank 1 and the ink supply pipe 32 are connected, the pressure in the connecting portion 20 tends to increase, but the displacement portion 123b of the check valve 123 relieves the pressure in FIG. As shown, it expands and deforms toward the communication portion 21 (ink chamber 11). 4C, in the state where ink is supplied as indicated by the arrow I, the displacement portion 123b of the check valve 123 returns to the original state, and ink is supplied from the ink chamber 11 of the ink tank 1. The communicating portion 21 is opened so as not to hinder the flow of ink toward the tube 32 side.

  Since the check valve 123 is provided with the displacement portion 123b, the ink in the connecting portion 20 is not pressed and moved to the ink supply pipe 32 side as in the first embodiment, and the meniscus is broken. Ink leakage is suppressed. Further, when the ink tank is erroneously attached, the ink in the connecting portion 20 is suppressed from being pushed into the ink supply pipe 32, and the color mixing of the ink in the ink supply pipe can be suppressed.

  Here, it is preferable that the displacement volume S2 of the displacement portion 123b of the check valve 123 satisfies the same conditions as in the first embodiment. However, it is a more preferable configuration that the displacement volume S2 is configured to be able to displace more than that volume (this displaceable volume is S2A). The displaceable volume S2A makes it possible to enjoy the effects of the present invention even when the design tolerance or the amount of ink supply pipes entering different ink supplies in different printers is different.

DESCRIPTION OF SYMBOLS 1 Ink tank 5 Joint part 11 Ink chamber 20 Connection part 21 Communication part 22 Ink supply port 23 Check valve 23a Outer peripheral area 23b Displacement part (central area)
24 Valve body 25 Spring 26 Seal body 30 Inkjet head 31 Nozzle 32 Ink supply pipe

Claims (10)

An ink chamber;
A communication part that communicates with the ink chamber, and a connection part that provides an ink supply port;
A valve body disposed in the connecting portion and closing the ink supply port;
In an ink tank comprising:
The communication portion includes a check valve that allows ink flow from the ink chamber to the ink supply port side and blocks ink flow from the connecting portion to the ink chamber;
The ink tank is characterized in that the check valve has a displacement portion in a central region.   The ink tank according to claim 1, wherein the displacement portion of the check valve has a structure that can be expanded and contracted.   2. The ink tank according to claim 1, wherein the displacement portion of the check valve has a thickness in a central region smaller than a thickness in an outer peripheral region.   The check valve is formed of an elastic body, and the displacement portion is deformed to the ink chamber side when the pressure of ink in this direction is increased in a state where the flow of ink from the connecting portion to the ink chamber is blocked. The ink tank according to claim 1.   A supply port of an ink tank is attached to an ink supply pipe communicating with an ink jet head, and the valve body moves inward of the connecting portion, whereby the displacement portion of the check valve is deformed to the ink chamber side. The ink tank according to claim 1.   The ink tank according to claim 1, wherein the displacement portion is a region corresponding to the communication portion. An inkjet head equipped with an ink supply tube;
An ink tank comprising: an ink chamber; a communicating portion communicating with the ink chamber; a connecting portion provided with an ink supply port; and a valve body disposed inside the connecting portion to close the ink supply port;
In an inkjet recording apparatus in which an ink tank is configured to be detachable with respect to an inkjet head,
The check valve of the ink tank has a displacement portion in the central region,
An ink tank is attached to the ink jet head, and an ink supply pipe contacts the valve body of the ink tank, and the valve body is moved inward of the connecting portion, whereby a displacement portion provided in a central region of the check valve The ink jet recording apparatus is characterized in that is deformed to the ink chamber side.   The inkjet recording apparatus according to claim 7, wherein the displacement portion of the check valve has a structure that can be expanded and contracted.   8. The ink jet recording apparatus according to claim 7, wherein the displacement portion of the check valve has a thickness in a central region thinner than a thickness in an outer peripheral region.   An ink tank supply port is attached to an ink supply pipe communicating with the ink jet head, and the moving volume in which the valve body moves inward of the connecting portion is defined as S1, and the displacement portion of the check valve is deformed to the ink chamber side. 8. The ink jet recording apparatus according to claim 7, wherein S1 ≧ S2 when the volume is S2.

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