JP2008162217A - Liquid discharge device and liquid tank - Google Patents

Abstract

A tank provided with a pressure control valve is miniaturized and the sealing performance of the pressure control valve with respect to an air opening hole is stabilized.
An ink jet recording apparatus of the present invention communicates with an ink reservoir chamber for storing ink to be supplied to an ejection head and an air layer in the ink reservoir chamber, and opens the air layer to the atmosphere. Pressure control chamber 53 having air release holes 53a and 53b, pressure control valves 54 and 57 capable of opening and closing the air release holes 53a and 53b of the pressure control chamber 53 by advancing and retreating operations, and elasticity by bending the pressure control valves 54 and 57 And an elastic arm 60 that blocks the pressure control chambers 54 and 57 from the atmosphere by closing the atmosphere opening holes 53a and 53b with force, and the elastic arm 60 and the pressure control valves 54 and 57 are provided. They are connected via rotatable turning mechanisms 63 and 64 having a rotation axis in a direction Y substantially perpendicular to the extending direction X and the bending direction Z of the elastic arm 60 at least.
[Selection] Figure 4

Description

  The present invention relates to a liquid ejection apparatus such as an inkjet recording apparatus that records an image on a recording medium by ejecting ink from an ejection head, and a liquid tank thereof.

2. Description of the Related Art Conventionally, an ink jet recording apparatus that supplies ink to an ejection head from an ink tank and ejects ink from a nozzle hole of the ejection head to record an image on a recording medium is known. In this device, when a temperature change or the like occurs, excessive positive pressure or negative pressure may be generated in the ink tank, and when the pressure propagates from the ink tank to the nozzle hole of the ejection head, a good meniscus in the nozzle hole is destroyed. It will be done. Therefore, there is provided an ink tank having an air opening hole and a pressure control valve that is biased in the closing direction by a coil spring in the air opening hole (see, for example, Patent Document 1). According to this, only when an excessive pressure is generated in the ink tank, the pressure control valve is moved in the opening direction against the coil spring by the pressure, and the atmosphere opening hole is opened to open the air in the ink tank. Pressure fluctuation is suppressed.
JP 2005-169892 A

  However, the coil spring that urges the pressure control valve has to have a large length in the expansion and contraction direction due to its structure if the pressure control valve is given sufficient urging force and stroke length, and the entire ink tank As the size increases. As a countermeasure, a leaf spring extends in a direction perpendicular to the stroke direction of the pressure control valve, one end of the leaf spring is fixed to the tank outer wall, and the other end that is a free end is attached to the pressure control valve. It is conceivable that the pressure control valve is urged by an elastic force caused by bending. Then, since the thin leaf spring can be arranged along the outer wall surface of the ink tank, the ink tank can be downsized as a whole.

  However, when a leaf spring is used as the urging means of the pressure control valve, the movement trajectory of the free end of the leaf spring has an arc shape centered on the fixed end, and therefore does not completely coincide with the stroke direction of the pressure control valve. Then, depending on the deflection angle of the leaf spring, an urging force biased from the leaf spring is applied to the pressure control valve, and the posture of the pressure control valve changes, and the sealing performance of the pressure control valve with respect to the air opening hole is not stable. It will be.

  Accordingly, an object of the present invention is to stabilize the sealing performance of the pressure control valve with respect to the air opening hole while reducing the size of the tank provided with the pressure control valve.

  The present invention has been made in view of the above-described circumstances, and a liquid ejection apparatus according to the present invention communicates with a liquid storage chamber in which a liquid to be supplied to an ejection head is stored and an air layer in the liquid storage chamber. A pressure control chamber having an air release hole for releasing the air layer to the atmosphere, a pressure control valve capable of opening and closing the air release hole of the pressure control chamber by an advancing and retreating operation, and an elasticity by bending the pressure control valve An elastic arm that urges in a closing direction with force and closes the atmosphere opening hole to shut off the pressure control chamber from the atmosphere, and the elastic arm and the pressure control valve are at least of the elastic arm. It is connected through a rotatable turning mechanism having a rotation axis in a direction substantially orthogonal to the extending direction and the bending direction.

  According to the above configuration, even if the movement trajectory of the elastic arm and the stroke direction of the pressure control valve do not completely match, even if the direction of the urging force by the elastic arm is biased, the bias is absorbed by the rotation mechanism, A biasing force with no bias is transmitted to the pressure control valve. Therefore, the posture change of the pressure control valve is prevented, and the sealing performance of the pressure control valve with respect to the atmosphere opening hole can be stabilized.

  The rotating mechanism includes a shaft portion provided on one of the other end of the elastic arm and the pressure control valve, and a bearing portion provided on any one of the shafts to pivotally support the shaft portion. You may have.

  According to the said structure, an attitude | position can be adjusted so that a pressure control valve can advance / retreat smoothly with respect to an elastic arm because a shaft part rotates with respect to a bearing part. The rotation mechanism may have at least a rotation axis in a direction substantially orthogonal to the extending direction and the bending direction of the elastic arm, but may be rotatable in multiple directions like a spherical bearing. That is, the rotation mechanism includes a ball portion provided on one of the other end of the elastic arm and the pressure control valve, and a ball bearing portion provided on any one of the balls to rotatably support the ball portion. It is good also as a structure which has.

  One end of the elastic arm is fixed to the outer wall surface of the tank forming the liquid storage chamber, the other end is connected to the outer end of the pressure control valve in the advancing / retreating direction, and the elastic arm is It may be arranged extending along the outer wall surface.

  According to the said structure, since an elastic arm is arrange | positioned so that the outer wall surface of a tank may be followed, it becomes possible to reduce a tank as a whole.

  The pressure control chamber is provided on the side of the liquid storage chamber, a protrusion is provided on the outer wall of the tank at the end opposite to the pressure control chamber, and one end of the elastic arm is It may be fixed to the protrusion.

  According to the said structure, an elastic arm extends from the protrusion part of one side to the pressure control chamber of the other side, and the full length of an elastic arm is ensured long. If it does so, the curvature of the motion locus | trajectory which used the one end part of the other end part of an elastic arm as a fulcrum will become small. Therefore, the motion trajectory of the elastic arm and the stroke direction of the pressure control valve are relatively approximate, and the bias of the biasing direction of the elastic arm with respect to the pressure control valve can be reduced.

  The air release hole has a negative pressure release hole and a positive pressure release hole, and the pressure control valve can open and close the negative pressure control valve capable of opening and closing the negative pressure release hole and the positive pressure release hole. A first arm portion that biases the negative pressure control valve so as to close the negative pressure release hole against the negative pressure in the pressure control chamber; And a second arm portion that urges the positive pressure control valve so as to close the positive pressure release hole against the positive pressure in the pressure control chamber.

  According to the above configuration, when both a negative pressure control valve and a positive pressure control valve exist as pressure control valves that require an urging force, the first arm portion and the second arm portion that urge each of them are integrated. Therefore, an increase in the number of parts can be suppressed. Further, since the first arm portion and the second arm portion are integrally formed, it is not necessary to position the first arm portion and the second arm portion separately when assembling the elastic arm to the product. Workability is also improved.

  The negative pressure control valve and the positive pressure control valve have different distances from the bending fulcrum of the elastic arm, the elastic arm has a substantially uniform thickness in the bending direction, and the first arm portion and the first pressure control valve Of the two arm portions, the arm portion connected to the control valve closer to the deflection fulcrum has a cross section orthogonal to the arm extending direction than the arm portion connected to the control valve far from the deflection fulcrum. The total area may be small.

  According to the said structure, since the thickness of an elastic arm is substantially uniform, manufacture of an elastic arm can be made easy. In addition, since the arm portion connected to the control valve closer to the deflection fulcrum has a smaller cross-sectional area than the arm portion connected to the control valve farther from the deflection fulcrum, the urging force to each control valve Can be made close to each other.

  The negative pressure control valve, the positive pressure control valve, and the deflection fulcrum are arranged on substantially the same straight line, and the control valve closer to the deflection fulcrum among the first arm portion and the second arm portion. The arm portion connected to the straight arm portion is formed in a straight line, and the arm portion connected to the control valve far from the bending fulcrum may be formed through both sides of the straight arm portion. Good.

  According to the above configuration, the arm portion connected to the control valve farther from the deflection fulcrum passes through both sides of the linear arm portion connected to the control valve closer to the deflection fulcrum. The portions can be formed on the same plane.

  In addition, the liquid tank of the present invention has a liquid storage chamber in which the liquid to be supplied to the discharge head is stored, and a pressure having an air release hole that communicates with the air layer of the liquid storage chamber and opens the air layer to the atmosphere. A control chamber, a pressure control valve capable of opening and closing the air opening hole of the pressure control chamber by an advancing and retreating operation, and urging the pressure control valve in a closing direction by an elastic force caused by bending, thereby closing the air opening hole. An elastic arm that shuts off the pressure control chamber from the atmosphere, and the elastic arm and the pressure control valve have a rotation axis that is at least substantially orthogonal to the extending direction and the bending direction of the elastic arm. It is connected through a free rotation mechanism.

  According to the above configuration, even if the movement trajectory of the elastic arm and the stroke direction of the pressure control valve do not completely match, even if the direction of the urging force by the elastic arm is biased, the bias is absorbed by the rotation mechanism, An urging force is applied to the pressure control valve without any bias. Therefore, it is possible to prevent the pressure control valve from changing in posture and stabilize the sealing performance of the pressure control valve with respect to the air opening hole.

  As is apparent from the above description, according to the present invention, it is possible to improve the stability of the sealing performance of the pressure control valve with respect to the air opening hole while reducing the size of the apparatus using the elastic arm. .

  Embodiments according to the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a perspective view showing a multifunction machine 1 having an inkjet recording apparatus 3 (liquid ejection apparatus) according to a first embodiment of the present invention. As shown in FIG. 1, the multifunction device 1 has a printer function, a scanner function, a copy function, and a facsimile function, and has an inkjet recording apparatus 3 for printing at the bottom of the housing 2 and the housing 2. The scanner device 4 is provided on the top of the screen. An opening 5 is formed on the front surface of the housing 2, a paper feed tray 6 of the ink jet recording apparatus 3 is provided below the opening 5, and a paper discharge tray 7 of the ink jet recording apparatus 3 is provided on the upper stage. . An opening / closing lid 8 is provided at the lower right portion of the front side of the inkjet recording apparatus 3, and a main tank mounting portion 9 (see FIG. 3) is provided inside the opening / closing lid 8. An operation panel 10 for operating the inkjet recording device 3, the scanner device 4, and the like is provided on the upper front side of the multifunction device 1. Further, when the multifunction device 1 is connected to an external computer, the multifunction device 1 can operate based on an instruction transmitted from the computer via a driver.

  FIG. 2 is a cross-sectional view schematically illustrating the ink jet recording apparatus 3 of the multifunction machine 1 shown in FIG. As shown in FIG. 2, a paper feed tray 6 is disposed on the bottom side of the multifunction machine 1. On the upper side of the paper feed tray 6, a paper feed driving roller 13 that supplies the uppermost layer of the papers 11 stacked on the paper feed tray 6 to the transport path 12 is provided. The conveyance path 12 makes a U-turn toward the front side after going upward from the back side of the paper feed tray 6, passes through the printing region 14, and is guided to the paper discharge tray 7 (see FIG. 1).

  An image recording unit 15 is provided in the printing area 14. A platen 20 larger than the paper size is disposed below the image recording unit 15. On the upstream side of the image recording unit 15, a conveyance roller 21 and a pinch roller 22 that nipping and conveying the paper 11 flowing through the conveyance path 12 onto the platen 20 are provided. On the downstream side of the image recording unit 15, a paper discharge roller 23 and a pinch roller 24 that sandwich the paper 11 on which image recording has been performed and convey it to the paper discharge tray 7 (see FIG. 1) are provided.

  The image recording unit 15 includes a known piezoelectric drive type discharge head 16 that discharges ink (liquid) from a large number of nozzle holes toward the conveyance path 12, and a sub tank 17 (liquid tank) that stores ink to be supplied to the discharge head 16. ), A head control board 18 that drives and controls the ejection head 16, and a carriage 19 on which these are mounted.

  The sub tank 17 has an ink inflow joint portion 41, and the ink replenishment mechanism 30 is appropriately connected to the ink joint portion 41 so that the sub tank 17 can be replenished with ink. The ink replenishing mechanism 30 includes a cartridge type main tank 25, an ink supply tube 26 having one end connected to the main tank 25, and an ink outflow joint portion 27 provided at the other end of the ink supply tube 26. Have. The ink outflow joint portion 27 is driven up and down by a driving means (not shown), and the ink outflow joint portion 27 is attached to and detached from the ink inflow joint portion 41 of the sub tank 17.

  FIG. 3 is a plan view of the main part of the ink jet recording apparatus 3 of the multifunction machine 1 shown in FIG. As shown in FIG. 3, a pair of flat guide rails 31 and 32 are extended above the platen 20 in the scanning direction orthogonal to the paper transport direction. The guide rails 31 and 32 are provided on substantially the same plane, and their upper surfaces are formed so as to be substantially parallel to the upper surface of the platen 20 and horizontally. The guide rails 31 and 32 support the carriage 19 of the image recording unit 15 so as to be slidable in the extending direction of the guide rails 31 and 32.

  A driving pulley (not shown) and a driven pulley 35 are provided on both ends in the scanning direction on the upper surface of the guide rail 32 on the downstream side in the sheet conveying direction. An annular timing belt 36 is wound between the driving pulley and the driven pulley 35. The carriage 19 is fixed to a part of the timing belt 36 on the bottom surface side. A motor 37 is connected to the shaft of the drive pulley. When the drive pulley is rotated forward and backward by the motor 37, the timing belt 36 moves between the drive pulley and the driven pulley 35. That is, due to the circumferential movement of the timing belt 36, the discharge head 16 (see FIG. 2), the sub tank 17, and the head control board 18 reciprocate together with the carriage 19 on the guide rails 31 and 32. The sub tank 17 has five ink storage chambers corresponding to the five colors of ink used for printing. Further, the sub tank 17 has a volume that can store an amount of ink that is greater than or equal to the amount of ink expected to be consumed in one printing process.

  An ink replenishing mechanism 30 for replenishing ink to the sub tank 17 and a positive pressure purge mechanism 40 for maintenance are disposed outside the printing area through which the paper passes. The ink replenishing mechanism 30 is provided on the front side (lower side in FIG. 3) of the guide rail 32 on one end side (right side in FIG. 3) of the carriage 19 in the scanning direction. The ink replenishing mechanism 30 has a main tank 25 that is detachably mounted on the stationary main tank mounting portion 9, and five main tanks 25 are prepared for each ink type.

  The positive pressure purge mechanism 40 is provided on the front side (lower side in FIG. 3) of the guide rail 32 on the other end side in the scanning direction of the carriage 19 (left side in FIG. 3). When the carriage 19 is moved to the left end of the guide rails 31 and 32 during maintenance, the positive pressure purge mechanism 40 joints the sub tank 17 from below and supplies compressed air (positive pressure) to the sub tank 17. The sludge and bubbles accumulated in the discharge head 16 (see FIG. 2) are purged toward a waste ink tank (not shown).

  4 is a cross-sectional view of the sub tank 17 of the ink jet recording apparatus 3 shown in FIG. As shown in FIG. 4, the sub tank 17 includes an ink inflow joint portion 41 at a position corresponding to the ink outflow joint portion 27 (see FIG. 2). The ink inflow joint portion 41 communicates with the outside through an inflow port 41a formed in the lower wall, and an inflow valve 42 is inserted so as to be movable up and down. A seal ring 43 is attached to the inner surface of the ink inflow joint portion 41 around the inlet 41a. The ink inflow joint portion 41 is provided with a coil spring 44 that urges the inlet valve 42 toward the seal ring 43.

  An ink storage chamber 46 communicates with the ink inflow joint portion 41 via an ink flow path 45. An outflow hole 46a is provided in the lower wall of the ink storage chamber 46, and the ink in the ink storage chamber 46 flows from the outflow hole 46a to the ejection head 16 (see FIG. 2). The sub tank 17 is provided with a gas circulation chamber 48 adjacent to the left side of the ink inflow joint portion 41 in the drawing (the side opposite to the ink storage chamber 46). The gas circulation chamber 48 communicates with the upper air layer of the ink storage chamber 46 through a serpentine labyrinth channel 47.

  The gas circulation chamber 48 communicates with the outside through a gas introduction hole 48a formed in the lower wall thereof. The gas circulation chamber 48 communicates with the upper pressure control chamber 53 through a communication hole 53c formed in the upper wall thereof. The pressure control chamber 53 is provided on the side of the ink storage chamber 46 via the labyrinth channel 47, and the gas introduction hole 48a and the communication hole 53c are in a positional relationship facing each other in the vertical direction. An open / close valve 49 is inserted into the gas circulation chamber 48 so as to be movable up and down. A seal ring 50 is attached around the gas introduction hole 48 a on the inner surface of the gas circulation chamber 48.

  The gas circulation chamber 48 is provided with a coil spring 51 that urges the on-off valve 49 toward the seal ring 50. A seal member 52 for closing the communication hole 53c and the periphery thereof is attached to the upper surface of the on-off valve 49 facing the communication hole 53c. Therefore, during the positive pressure purge, when the on-off valve 49 moves to the upper limit of the movable range and opens the gas introduction hole 48a, the seal member 52 closes the communication hole 53c. Then, the communication between the pressure control chamber 53 and the gas flow chamber 48 is blocked, and the volume of the space communicating with the ink storage chamber 46 is reduced by the amount corresponding to the pressure control chamber 53. Therefore, the on-off valve 49 also serves as a volume switching function.

  The pressure control chamber 53 communicates with the outside through a negative pressure release hole 53a and a positive pressure release hole 53b formed in the upper wall thereof. That is, in a normal time when the opening / closing valve 49 opens the communication hole 53c, the pressure control chamber 53 communicates with the ink storage chamber 46 via the gas flow chamber 48 and the labyrinth flow path 47, and the negative pressure release hole 53a and the positive pressure. The ink storage chamber 46 is opened to the atmosphere by the opening hole 53b. On the upper wall of the pressure control chamber 53, a stepped portion 53d that is lowered toward the direction away from the ink storage chamber 46 is provided, and a negative pressure release hole 53a is formed in the upper portion with the stepped portion 53d as a boundary. And a positive pressure release hole 53b is formed in the lower portion.

  The pressure control chamber 53 is provided with a negative pressure control valve 54 that opens and closes the negative pressure release hole 53a and a positive pressure control valve 57 that opens and closes the positive pressure release hole 53b. That is, the negative pressure release hole 53a and the positive pressure release hole 53b constitute an atmosphere release hole, and the negative pressure control valve 54 and the positive pressure control valve 57 constitute a pressure control valve. The negative pressure control valve 54 is inserted into the negative pressure release hole 53a so as to advance and retreat from below, and the positive pressure control valve 57 is inserted into the positive pressure release hole 53b so as to advance and retract from above.

  The negative pressure control valve 54 includes a seal seat portion 54a and a guide portion 54b that protrudes upward from the seal seat portion 54a and is inserted into the negative pressure release hole 53a from below. A seal ring 55 is attached to the upper surface of the seal seat portion 54a of the negative pressure control valve 54 so as to fit the guide portion 54b. The guide portion 54b partially has a clearance between the inner peripheral surface of the negative pressure release hole 53a, and this clearance communicates with the upper and lower spaces sandwiching the negative pressure release hole 53a.

  The positive pressure control valve 57 includes a seal seat portion 57a and a guide portion 57b that protrudes downward from the seal seat portion 57a and is inserted into the positive pressure release hole 53b from above. A seal ring 58 is attached to the lower surface of the seal seat portion 57a of the positive pressure control valve 57 so as to fit the guide portion 57b. The guide portion 57b partially has a clearance between the inner peripheral surface of the positive pressure release hole 53b, and this clearance communicates with the upper and lower spaces sandwiching the positive pressure release hole 53b.

  On the upper wall portion (outer wall surface) of the ink storage chamber 46 of the sub tank 17, a protruding portion 61 is provided at the end opposite to the pressure control chamber 53. A caulking rib 62 protrudes from the upper surface of the protruding portion 61. The sub tank 17 is provided with an elastic arm 60, which will be described in detail later, along the upper wall surface (outer wall surface). One end 60a of the elastic arm 60 is placed on the upper surface of the protrusion 61, and is fixed to the rib 62 by heat caulking. The other end 60d of the elastic arm 60 and the negative pressure control valve 54 are connected via a first rotation mechanism 63 having a rotation axis in a direction Y substantially perpendicular to the arm extending direction X and the bending direction Z. ing. The other end portions 60k, 60m of the elastic arm 60 and the positive pressure control valve 57 are connected via a second rotation mechanism 64 having a rotation axis in a direction Y substantially perpendicular to the arm extending direction X and the bending direction Z. ing.

  The elastic arm 60 urges the negative pressure control valve 54 and the positive pressure control valve 57 in the closing direction by the elastic force generated by the bending. That is, the elastic arm 60 urges the negative pressure control valve 54 so that the seal ring 55 of the negative pressure control valve 54 comes into close contact with the periphery of the negative pressure release hole 53a on the inner surface of the upper wall of the pressure control chamber 53. The positive pressure control valve 57 is urged so that the seal ring 58 of the positive pressure control valve 57 is in close contact with the periphery of the positive pressure release hole 53b on the outer surface of the pressure control chamber 53. As described above, the negative pressure control valve 54 and the positive pressure control valve 57 close the negative pressure release hole 53a and the positive pressure release hole 53b, thereby blocking the pressure control chamber 53 from the atmosphere.

  FIG. 5 is a plan view mainly showing the elastic arm 60 of the sub tank 17 shown in FIG. As shown in FIG. 5, the elastic arm 60 is a leaf spring member obtained by punching a substantially uniform thick metal plate. The elastic arm 60 extends linearly from one end 60a placed on the upper surface of the protruding portion 61, a mounting hole 60b formed in the one end 60a into which the rib 62 is press-fitted, and a central portion of the one end 60a. And a pair of second arm portions 60e and 60f extending from both end portions of the one end portion 60a through both sides of the first arm portion 60c.

  The negative pressure control valve 54, the positive pressure control valve 57, and the mounting hole 60b are arranged on substantially the same straight line in a plan view, and the negative pressure control valve 54 is one end 60a that is a bending fulcrum than the positive pressure control valve 57. Located close to. The area of the cross section perpendicular to the arm extending direction X of the first arm part 60c is smaller than the total area of the cross sections perpendicular to the arm extending direction X of the second arm part 60e and the second arm part 60f.

  FIG. 6 is a perspective view of a main part mainly showing the first arm part 60c of the elastic arm 60 shown in FIG. As shown in FIG. 6, the first arm portion 60c has a pair of protruding plate portions 60g and 60h bent downward from both sides of the other end portion 60d. Bearing portions 60i and 60j that are circular holes are formed in the protruding plate portions 60g and 60h.

  Further, the negative pressure control valve 54 has a rod portion 54c protruding upward from the seal seat portion 54a, and a cylindrical shaft portion 54d protruding on both sides in the rotational axis direction Y at the upper end portion of the rod portion 54c. Is provided. The shaft portion 54d is rotatably inserted into the bearing portions 60i and 60j, so that the first rotation having the rotation axis in the direction Y substantially perpendicular to the extending direction X and the bending direction Z of the first arm portion 60c. A moving mechanism 63 is configured.

  FIG. 7 is a main part perspective view mainly showing the second arm parts 60e and 60f of the elastic arm 60 shown in FIG. As shown in FIG. 7, the other end portions 60k and 60m of the second arm portions 60e and 60f are disposed so as to face each other in a direction in which they are close to each other. The second arm portions 60e and 60f have a pair of protruding plate portions 60n and 60p that are bent downward from the opposite ends of the other end portions 60k and 60m. Bearing portions 60q and 60r that are circular holes are formed on the protruding plate portions 60n and 60p.

  Further, the positive pressure control valve 57 has a rod portion 57c protruding upward from the seal seat portion 57a, and a cylindrical shaft portion 57d protruding on both sides in the rotational axis direction Y at the upper end portion of the rod portion 57c. Is provided. The shaft portion 57d is rotatably inserted into the bearing portions 60q and 60r, so that the second arm portions 60e and 60f have a rotation axis in the direction Y substantially perpendicular to the extending direction X and the bending direction Z. A two-turn mechanism 64 is configured.

  Referring again to FIG. 4, when a negative pressure of a predetermined value or more is generated in the ink storage chamber 46, the negative pressure is transmitted to the pressure control chamber 53 and the negative pressure control valve 54 is the first arm portion of the elastic arm 60. Move downward against 60c. Thereby, the seal ring 55 is separated from the peripheral wall surface of the negative pressure release hole 53a, and the negative pressure release hole 53a is opened. When the negative pressure in the ink storage chamber 46 becomes less than a predetermined value, it is transmitted to the pressure control chamber 53 and the negative pressure control valve 54 is raised by the urging force of the first arm portion 60c. At this time, even if the movement locus of the other end 60d of the first arm 60c and the stroke direction of the negative pressure control valve 54 are deviated, the deviation is absorbed by the first rotation mechanism 63 and the negative pressure control valve 54 Since the posture is not inclined, the seal ring 55 is uniformly pressed against the peripheral wall surface of the negative pressure release hole 53a.

  Similarly to the above, when a positive pressure of a predetermined value or more is generated in the ink storage chamber 46, the positive pressure is transmitted to the pressure control chamber 53 and the positive pressure control valve 57 is connected to the second arm portions 60 e and 60 f of the elastic arm 60. Move up against Accordingly, the seal ring 58 is separated from the peripheral wall surface of the positive pressure release hole 53b, and the positive pressure release hole 53b is opened. When the positive pressure in the ink storage chamber 46 becomes less than a predetermined value, it is transmitted to the pressure control chamber 53 and the positive pressure control valve 57 is lowered by the urging force of the second arm portions 60e and 60f. At this time, even if the movement trajectory of the other end portions 60k, 60m of the second arm portions 60e, 60f and the stroke direction of the positive pressure control valve 57 are displaced, the displacement is absorbed by the second rotating mechanism 64 and positive pressure is applied. Since the posture of the control valve 57 does not tilt, the seal ring 58 is uniformly pressed against the peripheral wall surface of the positive pressure release hole 53b.

  According to the above configuration, the urging force of the elastic arm 60 is applied evenly to the negative pressure control valve 54 and the positive pressure control valve 57 by the first and second rotating mechanisms 63 and 64, and the negative pressure control valve 54 and the positive pressure control valve 57 can be prevented from changing in posture. Therefore, it is possible to stabilize the sealing performance of the negative pressure control valve 54 and the positive pressure control valve 57 with respect to the negative pressure release hole 53a and the positive pressure release hole 53b.

  Further, one end portion 60 a of the elastic arm 60 is fixed to a protruding portion 61 provided on one end side of the sub tank 17, while the other end portions 60 d, 60 k, and 60 m of the elastic arm 60 are the other end side of the sub tank 17. The first and second rotation mechanisms 63 and 64 are connected to a negative pressure control valve 54 and a positive pressure control valve 57 provided in the first and second rotation mechanisms 63 and 64, respectively. Thereby, the elastic arm 60 extends long from one end side of the sub tank 17 to the other end side, and the curvature of the motion trajectory with the one end portion 60a of the other end portion 60d, 60k, 60m of the elastic arm 60 as a bending fulcrum is obtained. Get smaller. Therefore, the movement locus and the stroke directions of the negative pressure control valve 54 and the positive pressure control valve 57 are relatively approximate, and the biasing direction of the elastic arm 60 with respect to the negative pressure control valve 54 and the positive pressure control valve 57 is determined. The bias can be reduced.

  Further, since the elastic arm 60 is disposed substantially horizontally along the outer surface of the upper wall portion 46b of the sub tank 17, the height of the sub tank 17 can be reduced and the apparatus can be downsized as a whole. Furthermore, since the first arm portion 60c and the second arm portions 60e and 60f are integrally formed, an increase in the number of parts can be suppressed, and when the elastic arm 60 is assembled to the sub tank 17, the first arm portion 60c. And the second arm portions 60e and 60f need not be individually positioned, and the assembly workability is improved.

  In addition, the thickness of the elastic arm 60 is substantially uniform, and the first arm portion 60c connected to the negative pressure control valve 54 that is a valve closer to the one end portion 60a that is the bending fulcrum has one end portion that is the bending fulcrum. Since the total cross-sectional area is smaller than that of the second arm portions 60e and 60f connected to the positive pressure control valve 57, which is the valve far from 60a, the urging forces for the control valves 54 and 57 are close to each other. can do. Furthermore, since the second arm portions 60e and 60f connected to the positive pressure control valve 57 pass through both sides of the first arm portion 60c connected to the negative pressure control valve 54, each arm portion 60c, 60e, 60f can be formed on the same plane.

(Second Embodiment)
Next, a second embodiment will be described. FIG. 8 is a cross-sectional view of the sub tank 117 according to the second embodiment of the present invention. FIG. 9 is a plan view mainly showing the elastic arms 170 and 171 of the sub tank 117 shown in FIG. The difference from the first embodiment is that the elastic arms 170 and 171 are wire spring members. In addition, the same code | symbol is suitably attached | subjected to the structure similar to 1st Embodiment, and description is abbreviate | omitted. As shown in FIGS. 8 and 9, a protrusion 161 is provided on the outer surface of the upper wall of the ink storage chamber 46 of the sub tank 117 at the end opposite to the pressure control chamber 53. Mounting holes 161 a and 161 b are formed on both side surfaces of the protruding portion 161.

  The sub tank 117 is provided with elastic arms 170 and 171 along its upper wall surface. The elastic arm 170 attached to the negative pressure control valve 154 is a pair of wire spring members formed by bending a metal wire. The elastic arm 171 attached to the positive pressure control valve 157 is a pair of wire spring members similarly formed by bending a metal wire, and the length of the arm extending direction X and the rotational axis direction Y are more than the elastic arm 170. The width of is large.

  Specifically, the elastic arms 170 and 171 include one end portions 170a and 171a that are inserted and fixed in the mounting holes 161a and 161b of the projecting portion 161, and an arm portion that extends linearly from the one end portions 170a and 171a in the X direction. 170b, 171b, and shaft portions 170c, 171c projecting from the other ends of the arm portions 170b, 171b so as to face each other in the Y direction.

  The one end portions 170a and 171a are inserted into the mounting holes 161a and 161b of the projecting portion 161 and fixed by bonding, thereby serving as bending fulcrums for the elastic arms 170 and 171. The other end 170c of the elastic arm 170 and the negative pressure control valve 154 are connected via a first rotation mechanism 163 having a rotation axis in the Y direction. Similarly, the other end 171c of the elastic arm 171 and the positive pressure control valve 157 are connected via a second rotation mechanism 164 having a rotation axis in the Y direction.

  The negative pressure control valve 154 has a seal seat portion 154a and a guide portion 154b that protrudes upward from the seal seat portion 154a and is inserted into the negative pressure release hole 53a from below. A seal ring 55 is attached to the upper surface of the seal seat portion 154a so as to fit the guide portion 154b. Bearing portions 154c that are bottomed cylindrical holes are formed on both side surfaces of the guide portion 154b in the Y direction.

  The positive pressure control valve 157 includes a seal seat portion 157a, a guide portion 157b protruding downward from the seal seat portion 157a and inserted from above into the positive pressure release hole 53b, and a head portion 157c protruding upward from the seal seat portion 157a. And have. A seal ring 58 is attached to the lower surface of the seal seat portion 157a of the positive pressure control valve 157 so as to fit the guide portion 157b. Bearing portions 157d, which are bottomed cylindrical holes, are formed on both side surfaces of the head portion 157c in the Y direction.

  The shaft portions 170c and 171c of the elastic arms 170 and 171 are rotatably inserted into the bearing portions 154c and 157d of the negative pressure control valve 154 and the positive pressure control valve 157, respectively. That is, the shaft portion 170c and the bearing portion 154c constitute a first rotation mechanism 163 having a rotation axis in a direction Y substantially perpendicular to the arm extending direction X and the bending direction Z. The shaft portion 171c and the bearing portion 157c constitutes a second rotating mechanism 164 having a rotation axis in a direction Y substantially orthogonal to the arm extending direction X and the bending direction Z.

  When a negative pressure higher than a predetermined value is generated in the ink storage chamber 46, the negative pressure is transmitted to the pressure control chamber 53 and the negative pressure control valve 154 moves downward against the elastic arm 170. Thereby, the seal ring 55 is separated from the peripheral wall surface of the negative pressure release hole 53a, and the negative pressure release hole 53a is opened. When the negative pressure in the ink storage chamber 46 becomes less than a predetermined value, it is transmitted to the pressure control chamber 53 and the negative pressure control valve 154 is raised by the biasing force of the elastic arm 170. At this time, even if the movement locus of the elastic arm 170 and the stroke direction of the negative pressure control valve 154 are deviated, the deviation is absorbed by the first rotation mechanism 163 and the posture of the negative pressure control valve 154 is not inclined. The ring 55 is uniformly pressed against the peripheral wall surface of the negative pressure release hole 53a.

  Similarly to the above, when a positive pressure greater than a predetermined value is generated in the ink storage chamber 46, the positive pressure is transmitted to the pressure control chamber 53 and the positive pressure control valve 157 moves upward against the elastic arm 171. . Accordingly, the seal ring 58 is separated from the peripheral wall surface of the positive pressure release hole 53b, and the positive pressure release hole 53b is opened. When the positive pressure in the ink storage chamber 46 becomes less than a predetermined value, it is transmitted to the pressure control chamber 53 and the positive pressure control valve 157 is lowered by the urging force of the elastic arm 171. At this time, even if the movement path of the elastic arm 171 and the stroke direction of the positive pressure control valve 157 are deviated, the deviation is absorbed by the second rotating mechanism 164 and the posture of the positive pressure control valve 157 is not inclined. The ring 58 is uniformly pressed against the peripheral wall surface of the positive pressure release hole 53b. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

(Third embodiment)
Next, a third embodiment will be described. FIG. 10 is a cross-sectional view of the sub tank 217 according to the third embodiment of the present invention. FIG. 11 is a plan view mainly showing the elastic arm 260 of the sub tank 217 shown in FIG. The difference from the first embodiment is that spherical bearings are used for the first and second rotating mechanisms 263 and 264. In addition, the same code | symbol is suitably attached | subjected to the structure similar to 1st Embodiment, and description is abbreviate | omitted. As shown in FIGS. 10 and 11, the sub tank 217 is provided with an elastic arm 260 along its upper wall surface. The elastic arm 260 extends linearly from one end portion 260a placed on the upper surface of the projecting portion 61, a mounting hole 260b formed in the one end portion 260a to which the rib 62 is press-fitted and fixed, and a central portion of the one end portion 260a. The first arm portion 260c, the horseshoe-shaped second arm portion 260e extending from both end portions of the one end portion 260a through both sides of the first arm portion 260c, and the first and second arm portions 260c and 260e. Ball bearing portions 260s and 260t projecting downward from the other end portions 260d and 206k.

  The negative pressure control valve 254 includes a seal seat portion 254a, a guide portion 254b that protrudes upward from the seal seat portion 254a and is inserted into the negative pressure release hole 53a from below, and a rod portion 254c that protrudes upward from the guide portion 254b. And a ball portion 254d provided at the upper end of the rod portion 254c. The positive pressure control valve 257 includes a seal seat portion 257a, a guide portion 257b that protrudes downward from the seal seat portion 257a and is inserted into the positive pressure release hole 53b from above, and a rod portion 257c that protrudes upward from the guide portion 257b. , And a ball portion 257d provided at the upper end of the rod portion 257c.

  And the 1st rotation mechanism 263 is comprised because the ball | bowl part 254d of the negative pressure control valve 254 is rotatably supported by the concave space of the ball | bowl bearing part 260s of the 1st arm part 260c. Similarly, the second rotation mechanism 264 is configured by the ball portion 257d of the positive pressure control valve 257 being rotatably supported in the concave space of the ball bearing portion 260t of the second arm portions 260e and 260f. Here, the ball bearing portions 260s and 260t are opened downward, but are formed so as to cover the lower portion beyond the intermediate position in the height direction of the ball portions 254d and 257d. 257d does not come out of the ball bearing portions 260s and 260t. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

(Fourth embodiment)
Next, a fourth embodiment will be described. FIG. 12 is a cross-sectional view of a sub tank 317 according to the fourth embodiment of the present invention. A difference from the first embodiment is that a semipermeable membrane 382 is provided in a flow path 347 connecting the ink storage chamber 46 and the gas flow chamber 48. In addition, the same code | symbol is suitably attached | subjected to the structure similar to 1st Embodiment, and description is abbreviate | omitted. As shown in FIG. 12, a resin film 380 is used on a part of the outer wall of the ink flow path 45 that connects the ink inflow joint portion 41 and the ink storage chamber 46. Further, the resin film 381 is also used for a part of the outer wall of the flow path 347 connecting the ink storage chamber 46 and the gas circulation chamber 48. Further, a semipermeable membrane 382 that allows gas to pass without passing ink is interposed in the flow path 347 connecting the ink storage chamber 46 and the gas flow chamber 48 so as to block the flow path 347. That is, the gas pressure in the ink storage chamber 46 passes through the semipermeable membrane 382 and is transmitted to the gas circulation chamber 48 and the pressure control chamber 53, but the ink in the ink storage chamber 46 does not pass through the semipermeable membrane 382, and the ink Does not flow into the gas flow chamber 48. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

  Each of the above-described embodiments is an application of the present invention to an ink jet recording apparatus, but may be applied to an apparatus that discharges a liquid other than ink. Moreover, in each embodiment, although this invention is applied to a subtank, if it is a tank which stores a liquid, it will not be limited to this, For example, you may apply to a main tank.

  As described above, the liquid ejection device and the liquid tank according to the present invention can improve the stability of the sealing performance of the pressure control valve with respect to the atmosphere opening hole while reducing the size of the device using the elastic arm. The present invention can be widely applied to an ink jet recording apparatus that has an excellent effect and can exhibit the significance of this effect.

1 is a perspective view showing a multifunction machine having an inkjet recording apparatus (liquid ejection apparatus) according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view schematically illustrating the inkjet recording apparatus of the multifunction machine illustrated in FIG. 1. FIG. 2 is a plan view of a main part in an ink replenishment state of the inkjet recording apparatus of the multifunction peripheral shown in FIG. It is sectional drawing of the sub tank of the inkjet recording device shown in FIG. FIG. 5 is a plan view mainly showing an elastic arm of the sub tank shown in FIG. 4. It is a principal part perspective view mainly showing the 1st arm part of the elastic arm shown in FIG. It is a principal part perspective view mainly showing the 2nd arm part of the elastic arm shown in FIG. It is sectional drawing of the sub tank of 2nd Embodiment of this invention. FIG. 9 is a plan view mainly showing an elastic arm of the sub tank shown in FIG. 8. It is sectional drawing of the sub tank of 3rd Embodiment of this invention. FIG. 11 is a plan view mainly showing an elastic arm of the sub tank shown in FIG. 10. It is sectional drawing of the sub tank of 4th Embodiment of this invention.

Explanation of symbols

1 MFP 3 Inkjet recording device (liquid ejection device)
16 Discharge head 17 Sub tank (liquid tank)
46 Ink storage chamber (liquid storage chamber)
53 Pressure control chamber 53a Negative pressure release hole (atmosphere release hole)
53b Positive pressure release hole (atmosphere release hole)
54 Negative pressure control valve (pressure control valve)
54d, 57d Shaft 57 Positive pressure control valve (pressure control valve)
60 elastic arm 60c first arm portion 60e, 60f second arm portion 60i, 60j, 60q, 60r bearing portion 61 projecting portion 63 first rotation mechanism 64 second rotation mechanism

Claims (8)

A liquid storage chamber for storing liquid to be supplied to the discharge head;
A pressure control chamber communicated with the air layer of the liquid storage chamber and having an air release hole for opening the air layer to the atmosphere;
A pressure control valve capable of opening and closing the atmosphere opening hole of the pressure control chamber by an advancing and retreating operation;
An elastic arm that urges the pressure control valve in a closing direction by an elastic force due to bending, and blocks the pressure control chamber from the atmosphere by closing the atmosphere opening hole,
The elastic arm and the pressure control valve are connected via a rotatable rotation mechanism having a rotation axis in a direction substantially orthogonal to at least the extending direction and the bending direction of the elastic arm. Liquid ejection device.   The rotating mechanism includes a shaft portion provided on one of the other end of the elastic arm and the pressure control valve, and a bearing portion provided on any one of the shafts to pivotally support the shaft portion. The liquid ejection apparatus according to claim 1, comprising:   One end of the elastic arm is fixed to the outer wall surface of the tank forming the liquid storage chamber, the other end is connected to the outer end of the pressure control valve in the advancing / retreating direction, and the elastic arm is The liquid ejection device according to claim 1, wherein the liquid ejection device is disposed so as to extend along the outer wall surface.   The pressure control chamber is provided on the side of the liquid storage chamber, a protrusion is provided on the outer wall of the tank at the end opposite to the pressure control chamber, and one end of the elastic arm is The liquid ejection device according to claim 3, wherein the liquid ejection device is fixed to the protruding portion. The air release hole has a negative pressure release hole and a positive pressure release hole,
The pressure control valve has a negative pressure control valve capable of opening and closing the negative pressure release hole, and a positive pressure control valve capable of opening and closing the positive pressure release hole,
The elastic arm resists a negative pressure in the pressure control chamber, a first arm portion that biases the negative pressure control valve so as to close the negative pressure release hole, and a positive pressure in the pressure control chamber. 5. The liquid ejection device according to claim 1, further comprising a second arm portion that urges the positive pressure control valve so as to close the positive pressure release hole. The negative pressure control valve and the positive pressure control valve have different distances from the deflection fulcrum of the elastic arm, and the elastic arm has a substantially uniform thickness in the deflection direction,
Of the first arm part and the second arm part, the arm part connected to the control valve closer to the deflection fulcrum is arm than the arm part connected to the control valve farther from the deflection fulcrum. The liquid ejection apparatus according to claim 5, wherein a total area of a cross section orthogonal to the extending direction is small. The negative pressure control valve, the positive pressure control valve, and the bending fulcrum are arranged on substantially the same straight line,
Of the first arm part and the second arm part, the arm part connected to the control valve closer to the deflection fulcrum is formed linearly,
The liquid ejecting apparatus according to claim 5 or 6, wherein an arm portion connected to the control valve far from the bending fulcrum is formed so as to pass through both sides of the linear arm portion. A liquid storage chamber for storing liquid to be supplied to the discharge head;
A pressure control chamber that communicates with the air layer of the liquid storage chamber and has an air opening hole for opening the air layer to the atmosphere;
A pressure control valve capable of opening and closing the atmosphere opening hole of the pressure control chamber by an advancing and retreating operation;
An elastic arm that urges the pressure control valve in a closing direction by an elastic force due to bending, and blocks the pressure control chamber from the atmosphere by closing the atmosphere opening hole,
The elastic arm and the pressure control valve are connected via a rotatable rotation mechanism having a rotation axis in a direction substantially orthogonal to at least the extending direction and the bending direction of the elastic arm. Liquid tank.

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