JP4876800B2 - Valve unit and liquid ejecting apparatus - Google Patents

Description

  The present invention relates to a valve unit and a liquid ejecting apparatus.

  As a liquid ejecting apparatus that ejects liquid from a liquid ejecting head to a target, for example, an ink jet printer (hereinafter simply referred to as “printer”) is known. The printer includes an ink cartridge (liquid container) that stores ink (liquid) and a recording head (liquid ejecting head) that can eject ink. Then, the ink in the ink cartridge is supplied to the recording head side through the ink supply path (liquid supply path), and printing is performed by ejecting the ink from the nozzles of the recording head to the recording medium.

In such a printer, it is desirable to stably supply ink from the ink cartridge to the recording head. In order to meet these demands, printers having a valve unit for adjusting the flow pressure of ink on a carriage have recently been proposed. (For example, refer to Patent Document 1.)
Specifically, the valve unit provided in the printer in Patent Document 1 includes a channel-forming member having a regularity in which a recess is formed, a film member that seals the recess of the channel-forming member, and the film. And a valve member that opens and closes an ink inflow port to a pressure chamber formed by sealing the concave portion of the flow path forming member with the member. This valve member is normally urged to a closed state in which the ink inlet is closed by a valve urging spring disposed in the pressure chamber. When the ink is ejected from the nozzle and the ink flows out from the outlet of the pressure chamber, a negative pressure is generated in the pressure chamber, and the film is displaced in a direction that decreases the volume of the pressure chamber. Due to the pressing force based on the displacement of the film, the valve member is separated from the inflow port against the urging force of the valve urging spring, whereby new ink is supplied into the pressure chamber.

By the way, in such a printer, due to its structure, for example, when the ink cartridge is replaced, air may enter the ink supply path, and this air may be mixed into the ink as bubbles. When such bubbles reach the pressure chamber of the valve unit, a negative pressure is generated in the pressure chamber, so that air passes through the film and moves into the pressure chamber, and bubbles mixed in the ink grow. was there. Since such bubbles may cause the ink supply to the recording head to become unstable, it is desirable to prevent the bubbles from growing as much as possible. Therefore, as a measure for suppressing such bubble growth, the pressure chamber film has conventionally been made of a material having a high gas barrier property.
JP 200595861 A

  However, many materials having a high gas barrier property have a high elastic modulus, and a film made of the gas barrier material becomes hard, and the responsiveness when displacing according to the negative pressure in the pressure chamber is lowered. If the responsiveness of the film is thus reduced, the ink supply to the recording head becomes unstable eventually, resulting in a decrease in print quality. In addition, since gas barrier materials and water vapor barrier materials are generally expensive, there is a problem in that the use of these materials increases the manufacturing cost.

  In addition to the ink jet printer, a liquid ejecting apparatus that supplies the liquid contained in the liquid container to the liquid ejecting head through the liquid supply path and ejects the liquid through the nozzles provided in the liquid ejecting head. In fact, these facts are generally common.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a valve unit and a liquid ejecting apparatus that can suppress bubble growth in a pressure chamber provided in the middle of a liquid supply path. There is.

In order to achieve the above object, a valve unit of the present invention is provided in the middle of a liquid supply path, and has an inflow port for allowing liquid to flow from the upstream side of the liquid supply path and a liquid to the downstream side of the liquid supply path. A pressure chamber having an outlet for letting out the gas, a flexible member that forms part of the wall surface of the pressure chamber and that is displaced based on pressure fluctuations in the pressure chamber, and the pressure by the flexible member A liquid filling chamber provided outside the pressure chamber so as to form a partition with the chamber and filled with a liquid , and the liquid filling chamber is a wall surface constituted by other than the flexible member At least a portion of the liquid filling chamber is made of a flexible sealing member, and the area of the wall portion of the liquid filling chamber constituted by the flexible member is the wall surface of the liquid filling chamber constituted by the sealing member. It is smaller than the area of the portion To.

According to this configuration, since the liquid filling chamber constituting the partition wall with the pressure chamber is provided by the flexible member on the outside of the pressure chamber, the outside (in the atmosphere) air is a flexible member such as a film. Therefore, even if bubbles exist in the pressure chamber, the bubble growth can be suppressed. Therefore, without using an expensive gas barrier material with a high elastic modulus as the flexible member, it is possible to use a film that is rich in flexibility and inexpensive, while ensuring good responsiveness of the flexible member, Bubble growth in the pressure chamber can be suppressed. Further, by attaching the sealing member in a predetermined bending state, a pressure change in the liquid filling chamber accompanying the displacement of the flexible member is allowed by the bending deformation of the sealing member. Further, even when the volume of the liquid filled in the liquid filling chamber changes due to a temperature change or the like, the pressure change in the liquid filling chamber is allowed due to the deformation of the sealing member. Therefore, it is possible to suppress the growth of bubbles in the pressure chamber while ensuring good response of the flexible member with an extremely simple configuration. Furthermore, in the liquid filling chamber, by ensuring the area of the wall surface portion constituted by the sealing member rather than the wall surface portion constituted by the flexible member, while ensuring good responsiveness of the flexible member, The deformation load applied to the sealing member can be reduced.

In the valve unit of the present invention, it is preferable that the inside of the liquid filling chamber is filled with a nonpolar liquid.
According to this configuration, since the inside of the liquid filling chamber is filled with a nonpolar liquid such as oils, the general components having polarity such as oxygen, nitrogen, carbon dioxide, etc., which are main components of air The gas hardly dissolves in the liquid in the liquid filling chamber. Therefore, even if the liquid filling chamber is made of a material having inferior gas barrier properties, the amount of dissolved gas is kept low in the liquid filling chamber, so that the movement of air into the pressure chamber through the flexible member is also suppressed. .

  In the valve unit of the present invention, the wall surface of the liquid filling chamber, at least a part of which is constituted by the sealing member, is provided at a position facing the flexible member with the liquid filling chamber interposed therebetween. Is desirable.

  According to this configuration, in the liquid filling chamber, the apparatus can be reduced in size by providing the wall surface configured by the flexible member that needs to ensure the surface area and the wall surface configured by the sealing member at opposing positions. Can be achieved.

  In the liquid ejecting apparatus according to the aspect of the invention, the liquid container that stores the liquid, the liquid ejecting head that can eject the liquid onto the target, and the liquid that is supplied from the liquid container side to the liquid ejecting head side. The liquid supply path and the valve unit described above are provided.

  According to this configuration, a flexible and inexpensive film can be used without using a high elastic modulus and expensive gas barrier material as the flexible member, and the flexible member has good responsiveness. While ensuring, the bubble growth in the pressure chamber can be suppressed.

(First embodiment)
Hereinafter, a first embodiment in which the present invention is embodied in an ink jet printer (hereinafter simply referred to as a printer) will be described with reference to FIGS. In the following description of the present specification, the terms “front-rear direction”, “left-right direction”, “up-down direction” refer to the front-rear direction (sub-scanning direction) indicated by arrows in FIG. 1 unless otherwise specified. The horizontal direction (main scanning direction) and the vertical direction (gravity direction) indicated by arrows in FIGS.

  As shown in FIG. 1, a printer 11 as a liquid ejecting apparatus according to this embodiment includes a main body case 12 having a substantially rectangular box shape. A platen 13 is installed in the lower part of the main body case 12 along the left-right direction which is the longitudinal direction thereof. The platen 13 is a support for supporting the recording paper P as a target, and the recording paper P is fed onto the platen 13 along a front-rear direction that is a sub-scanning direction by a paper feeding mechanism (not shown). It is like that. A rod-shaped guide member 14 is installed in the main body case 12 in parallel with the longitudinal direction (left-right direction) of the platen 13.

  A carriage 15 is supported on the guide member 14 in a state where the carriage 15 can reciprocate in the axial direction (left-right direction) of the guide member 14. The carriage 15 is connected to a carriage motor 17 via an endless timing belt 16 stretched between a pair of pulleys 16a. Therefore, the carriage 15 is reciprocated along the guide member 14 by driving the carriage motor 17.

  A recording head 18 as a liquid ejecting head is provided on the surface of the carriage 15 that faces the platen 13. On the carriage 15, a plurality of valve units 19 that supply ink as liquid to the recording head 18 are provided corresponding to the colors of ink used in the printer 11. Similarly, a plurality of nozzles 20 (see FIG. 2, only one is shown in the figure) corresponding to the ink color are formed on the lower surface of the recording head 18. Then, printing is performed by ejecting ink droplets onto the recording paper P fed from each nozzle 20 onto the platen 13.

  A cartridge holder 21 is provided at the right end of the main body case 12, and a home position HP serving as a retraction position of the recording head 18 is provided between the cartridge holder 21 and the platen 13. Before starting printing, various maintenance processes such as cleaning the recording head 18 are performed at the home position HP.

  A plurality of ink cartridges 22 as liquid containers are detachably mounted on the cartridge holder 21. Each ink cartridge 22 includes a rectangular box-shaped case 23. In the case 23, a bag-like ink pack 24 (see FIG. 2) made of a flexible film filled with ink of different colors for each ink cartridge 22 is accommodated. Each ink cartridge 22 is connected to each valve unit 19 on the carriage 15 via the ink supply tube 25 by being connected to the upstream end of the ink supply tube 25 when mounted on the cartridge holder 21. It has become so.

  A pressure unit 26 is mounted on the upper side of the cartridge holder 21. The pressurizing unit 26 is a device that pumps pressurized air into the ink cartridge 22 through an air supply path 27, and includes a pressurizing pump 28, a pressure detector 29, and an atmosphere release valve 30. The pressure of the pressurized air in the air supply path 27 is detected by the pressure detector 29, and drive control of the pressure pump 28 is performed based on this detected value. Further, when the pressure in the air supply path 27 becomes excessive due to some circumstances, the atmosphere release valve 30 is opened to release the pressure in the air supply path 27 into the atmosphere.

  The air supply path 27 is branched into the same number as the number of ink cartridges 22 with a distributor 31 disposed downstream of the atmosphere release valve 30 as a boundary. Each branched air supply path 27 is connected to the corresponding ink cartridge 22 at each downstream end and communicates with the case 23 of the ink cartridge 22. Therefore, when the pressurizing pump 28 of the pressurizing unit 26 is driven, the pressurized air pumped from the pressurizing pump 28 is introduced into each case 23 of the ink cartridge 22 via the air supply path 27. It has become so.

  As shown in FIG. 2, the inside of the case 23 of the ink cartridge 22 is a pressurizing chamber 32, and the ink pack 24 is accommodated in the pressurizing chamber 32. The pressurized air pumped from the pressurizing pump 28 through the air supply path 27 is introduced into the pressurizing chamber 32, and the ink pack 24 is crushed by the air pressure of the pressurized air. Then, the ink in the ink pack 24 is led out to the ink supply tube 25 and is pumped to the valve unit 19 through the ink supply tube 25.

  In the valve unit 19, an inflow path 19 a for allowing ink supplied from the ink supply tube 25 to flow into the valve unit 19 and an outflow for discharging ink from the valve unit 19 to the recording head 18 side. A path 19b is formed. In the present embodiment, an ink supply path (liquid supply) for supplying ink (liquid) from the ink cartridge 22 side to the recording head 18 side by the ink supply tube 25, the inflow path 19a, and the outflow path 19b described above. Road).

  On the other hand, an ink flow path 18 a communicating with the outflow path 19 b of the valve unit 19 is formed in the recording head 18, and between the ink flow path 18 a and the nozzle 20 formed on the lower surface of the recording head 18. Is provided with an ink chamber R capable of temporarily storing ink. Above the ink chamber R, a vibration plate (not shown) that vibrates in the vertical direction and expands and contracts the volume in the ink chamber R is disposed, and the vibration plate is vibrated above the vibration plate. A piezoelectric element (not shown) is provided. The piezoelectric element contracts and expands in the vertical direction to vibrate the vibration plate in the vertical direction, so that ink is ejected from the nozzles 20 of the recording head 18 as droplets of a predetermined volume.

Next, a specific configuration of the valve unit 19 will be described with reference to FIG.
As shown in FIG. 3A, the valve unit 19 has a structure in which a first flow path forming member 33, a second flow path forming member 34, and a liquid filling chamber forming member 35 each having a regular shape are laminated. ing. That is, in the valve unit 19, the second flow path forming member 34 is joined on the first flow path forming member 33 and the liquid filling chamber forming member 35 is joined on the second flow path forming member 34. Thus, the unit structure is formed by integrating the three layers.

  First, the first flow path forming member 33 has a substantially rectangular parallelepiped shape, and a concave portion 33a having a circular shape in plan view is formed on an upper surface of the flat surface, and an inner bottom surface of the concave portion 33a is formed. One convex portion 33b having a truncated cone shape is formed at a position eccentric from the center. The inflow path 19a described above is formed in an L shape in the first flow path forming member 33 by opening an ink inlet 39a into the concave section 33a at the upper end surface of the convex section 33b. Is formed.

  Next, the second flow path forming member 34 has a substantially rectangular parallelepiped shape whose thickness in the vertical direction is smaller than that of the first flow path forming member 33, and a lower surface forming a planar shape of the first flow path forming member 33. It is joined to the top surface. In addition, on the upper surface of the second flow path forming member 34, a concave part 34 a having a circular shape in plan view is formed that partially overlaps the concave part 33 a of the first flow path forming member 33 in the vertical direction. The concave portion 34 a is provided so that the center thereof is positioned eccentric to the opposite side to the convex portion 33 b when viewed from the center of the concave portion 33 a of the first flow path forming member 33. An annular projecting edge 34b is formed on the upper surface of the second flow path forming member 34 in such a manner that the inner peripheral surface of the recess 34a extends upward.

  A central hole 34 c is formed through the center of the bottom of the recess 34 a in the second flow path forming member 34 so as to communicate the recess 34 a with the recess 33 a of the first flow path forming member 33. The central hole 34c is formed so that the opening area thereof is smaller than the opening area of the concave portion 33a of the first flow path forming member 33 and is located within the opening range of the concave portion 33a.

  In addition, on the inner bottom surface of the recess 34a in the second flow path forming member 34, the outflow passage 19b described above opens the ink outlet 39b on the inner bottom surface of the recess 34a at a position outside the center hole 34c. In this manner, the second flow path forming member 34 and the first flow path forming member 33 are formed to penetrate therethrough.

  Moreover, the upper end opening of the recessed part 34a is sealed in the upper end surface of the protrusion part 34b in the 2nd flow-path formation member 34 in the state which the partition film 37 as a flexible member bent a little in the recessed part 34a. So that it is fixed. In addition, a disc-shaped pressing plate 38 having an area smaller than the opening area of the recess 34 a is fixed to a substantially central portion on the inner surface facing the recess 34 a of the partition film 37. The recess 34a is sealed with the partition film 37, so that the recess 33a of the first channel forming member 33, the recess 34a of the second channel forming member 34, and both the recesses 33a, A pressure chamber 39 made up of each internal space of the central hole 34 c communicating with the space 34 a is formed so that a part of the wall surface is constituted by the partition film 37.

  Next, the liquid filling chamber forming member 35 has a substantially rectangular parallelepiped shape in which the thickness in the vertical direction is about the middle between the thicknesses of the first flow path forming member 33 and the second flow path forming member 34. The lower surface having a shape is joined to the upper surface of the second flow path forming member 34. The liquid filling chamber forming member 35 has a through hole 35a penetrating in the vertical direction (thickness direction). The through hole 35a has an opening area of the recess 34a of the second flow path forming member 34. The liquid filling chamber forming member 35 is formed so as to be concentric with the concave portion 34 a of the second flow path forming member 34 when the liquid filling chamber forming member 35 is stacked on the second flow path forming member 34.

  Further, a sealing film 40 as a sealing member made of a flexible material is fixed to the upper surface of the liquid filling chamber forming member 35 so as to seal the upper end opening of the through hole 35a in a predetermined bending state. ing. In addition, a disk-shaped pressure receiving plate 41 having an area smaller than the opening area of the through hole 35a is fixed to a substantially central portion on the inner surface facing the inside of the through hole 35a of the sealing film 40. Then, the upper end opening of the through hole 35a is sealed with the sealing film 40, and the inside of the space surrounded by the sealing film 40 and the through hole 35a is filled with a nonpolar liquid such as oil. A liquid filling chamber 42 is formed. That is, in the valve unit 19, a liquid filling chamber 42 composed of the internal space of the through hole 35 a is partly formed by the sealing film 40 and a partition wall from the pressure chamber 39 is formed by the partition film 37 described above. Is formed. In the liquid filling chamber 42, the area of the wall surface constituted by the partition film 37 is such that the opening area of the recess 34 a to which the partition film 37 is fixed is the opening area of the through hole 35 a to which the sealing film 40 is fixed. Therefore, it is smaller than the area of the other wall surface constituted by the sealing film 40.

Next, the internal configuration of the pressure chamber 39 will be described.
As shown in FIG. 3A, a base portion 43 is provided at a substantially central portion of the inner bottom surface of the lower concave portion 33 a constituting the pressure chamber 39, and the valve member 44 is supported by the base portion 43. Has been. The valve member 44 has an action point side arm portion 44a having a valve body 45 that is opposed to the inflow port 39a fixed to the tip (left end in FIG. 3A), and the tip (upper end in FIG. 3A) on the upper side. A force point side arm portion 44b that confronts the pressing plate 38 in the concave portion 34a, and a connecting arm portion 44c that connects the two arm portions 44a and 44b.

  In addition, the valve member 44 has an angle at which the connecting portion between the action point side arm portion 44a and the connecting arm portion 44c and the connecting portion between the force point side arm portion 44b and the connecting arm portion 44c form a substantially “h” shape. By being connected, the action point side arm portion 44a and the force point side arm portion 44b are formed in a shape in which the axial directions of each other intersect at right angles. A support shaft 44d that protrudes laterally (in the direction orthogonal to the paper surface in FIG. 3A) from the connection portion between the action point side arm portion 44a and the connection arm portion 44c is a bearing portion 43a of the base portion 43. The valve member 44 is opened and closed between a valve closing state in which the valve body 45 closes the inflow port 39a and a valve opening state in which the inflow port 39a is opened. It has become.

  A valve biasing spring 46 made of a compression coil spring is disposed in a position facing the inflow port 39a and the valve body 45 in the lower concave portion 33a constituting the pressure chamber 39. The valve urging spring 46 has one end (upper end in FIG. 3 (a)) in contact with the lower surface of the second flow path forming member 34, while the other end (FIG. ) Is in contact with the valve body 45, the valve body 45 is always urged in the direction of closing the inflow port 39a.

Next, the internal configuration of the liquid filling chamber 42 will be described.
As shown in FIG. 3A, a pressure receiving spring 47 made of a compression coil spring having a diameter larger than that of the projecting edge portion 34 b of the second flow path forming member 34 is disposed in the through hole 35 a constituting the liquid filling chamber 42. It is accommodated in such a manner as to surround the projecting edge 34b. The pressure receiving spring 47 has one end (upper end in FIG. 3A) in contact with the lower surface of the pressure receiving plate 41 and the other end (lower end in FIG. 3A) in the contracted power storage state. By contacting the upper surface of the second flow path forming member 34, the sealing film 40 is always urged through the pressure receiving plate 41 in the direction of expanding the internal volume of the liquid filling chamber 42.

  Therefore, in a state where the pressure receiving spring 47 urges the sealing film 40 via the pressure receiving plate 41, the sealing film 40 is displaced in a direction in which the internal volume of the liquid filling chamber 42 is increased. Is maintained in a state where negative pressure is generated. Therefore, the partition film 37 constituting the partition between the liquid filling chamber 42 and the pressure chamber 39 receives a negative pressure generated in the liquid filling chamber 42 and is biased toward the liquid filling chamber 42 side.

Next, the operation of the valve unit 19 configured as described above will be described.
First, prior to printing, the printer 11 discharges or sucks ink from the nozzle 20 in a state where the recording head 18 is disposed at the home position HP as a preparatory work, so that the inflow path 19a on the downstream side of the ink supply tube 25 is obtained. The pressure chamber 39, the outflow path 19b, the ink flow path 18a, and the ink chamber R are filled with ink.

  In the state where this preparatory work is completed, as shown in FIG. 3A, the valve member 44 is configured so that the action point side arm portion 44a is horizontal and the force point side arm portion 44b is vertical. The valve body 45 urged downward by the urging spring 46 abuts on the convex portion 33b and closes the inlet 39a. Further, the partition film 37 is biased upward by receiving the negative pressure in the liquid filling chamber 42.

  When printing is started after the print preparation work is completed, the pressure pump 28 is driven to send pressurized air to the pressure chamber 32 in the ink cartridge 22. The ink pack 24 is pressurized by the pressurized air, and the ink in the ink pack 24 is sent out to the valve unit 19 in a pressurized state. When the ink reaches the inlet 39a through the ink supply tube 25 and the inflow path 19a, the pressure of the pressurized ink is applied to the valve body 45, and the biasing force of the valve biasing spring 46 is more than this pressure. It is getting bigger.

  Therefore, at the start of printing, the inlet 39a of the pressure chamber 39 is closed by the valve body 45, and the upstream side and the downstream side of the valve unit 19 are not in communication. In this state, when the piezoelectric element provided in the recording head 18 is driven and ink is ejected from the nozzle 20, the ink flows out from the outlet 39 b of the pressure chamber 39 and is supplied to the ink chamber R.

  When the amount of ink in the pressure chamber 39 decreases with the outflow of ink, a negative pressure is generated in the pressure chamber 39. When the negative pressure becomes larger than a predetermined pressure (= the urging force of the pressure receiving spring 47), the partition film 37 bends toward the pressure chamber 39 against the negative pressure in the liquid filling chamber 42, and the partition film 37 The pressing plate 38 provided at the center of the lower surface is displaced downward. At this time, when a pressing force is applied to the tip of the force point side arm portion 44b of the valve member 44 that the displaced pressing plate 38 faces below, the valve member 44 is centered on the support shaft 44d in FIG. 3 (a). Try to rotate in the direction of rotation. When the pressing force by the pressing plate 38 becomes larger than the urging force of the valve urging spring 46, the valve member 44 is changed from the valve closing state shown in FIG. 3A to the valve opening state shown in FIG. Rotating displacement. Then, the valve body 45 is separated from the convex portion 33b against the urging force of the valve urging spring 46, and the inflow port 39a is opened. As a result, in the valve unit 19, the upstream inflow passage 19 a and the downstream pressure chamber 39 are in communication with each other.

  When the inflow port 39a is opened, the ink flows out from the pressure chamber 39 to the outflow passage 19b through the outflow port 39b as shown by an arrow in FIG. Ink flows into the pressure chamber 39 from the inflow path 19a filled with ink. When the negative pressure generated in the pressure chamber 39 by the inflowed ink becomes smaller than the predetermined pressure described above, the partition film 37 is bent toward the liquid filling chamber 42 and the pressing plate 38 is displaced upward toward the original position. When the pressing force applied to the tip of the force point side arm portion 44b in the valve member 44 becomes smaller than the biasing force of the valve biasing spring 46, the valve member 44 rotates counterclockwise in FIG. Then, the valve body 45 comes into contact with the convex portion 33b and the inflow port 39a is closed.

As described above, in the valve unit 19 of the present embodiment, the valve member 44 is repeatedly opened and closed, so that, during printing, according to the amount of ink ejected from the nozzle 20. Accordingly, an appropriate amount of ink can be stably supplied to the recording head 18.
According to the first embodiment as described above, the following effects can be obtained.

  (1) In the above embodiment, since the liquid filling chamber 42 that forms the partition wall with the pressure chamber 39 by the partition film 37 is provided outside the pressure chamber 39, the outside air directly moves into the pressure chamber 39. There is nothing to do. Therefore, even if bubbles are present in the pressure chamber 39, the growth of bubbles in the pressure chamber 39 can be suppressed. Therefore, since a high-flexibility and inexpensive film can be used without using an expensive gas barrier material having a high elastic modulus as the partition film 37, the pressure chamber can be secured while ensuring good responsiveness of the partition film 37. The bubble growth in 39 can be suppressed.

  (2) In the above embodiment, since the liquid filling chamber 42 is filled with a nonpolar liquid such as oil, it has polarity such as oxygen, nitrogen, carbon dioxide, etc., which are main components of air. A general gas hardly dissolves in the liquid in the liquid filling chamber 42. Therefore, even if the sealing film 40 is made of a material that is inferior in gas barrier property or water vapor barrier property, the amount of dissolved gas is kept low in the liquid filling chamber 42, so that the movement of air into the pressure chamber 39 is also suppressed. The

  (3) In the above embodiment, since the sealing film 40 is attached in a predetermined bending state, the pressure change in the liquid filling chamber 42 due to the displacement of the partition film 37 is caused by the bending deformation of the sealing film 40. Permissible. Further, even when the volume of the liquid filled in the liquid filling chamber 42 is changed due to a temperature change or the like, the pressure change in the liquid filling chamber 42 is allowed by the bending deformation of the sealing film 40. Therefore, it is possible to suppress the growth of bubbles in the pressure chamber 39 while ensuring good responsiveness of the partition film 37 with an extremely simple configuration.

  (4) In the above embodiment, in the liquid filling chamber 42, the wall surface constituted by the partition film 37 that needs to ensure the surface area is disposed at a position facing the wall surface constituted by the sealing film 40. Thereby, size reduction of the valve unit 19 can be achieved.

  (5) In the above embodiment, in the liquid filling chamber 42, the area of the wall surface portion constituted by the sealing film 40 is larger than the wall surface portion constituted by the partition film 37. Therefore, the deformation load applied to the sealing film 40 can be reduced while ensuring good responsiveness of the partition film 37.

(Second Embodiment)
Next, a second embodiment of the invention according to the present invention will be described with reference to FIGS. 4 (a) and 4 (b).

Since this embodiment also embodies the liquid ejecting apparatus according to the present invention in an ink jet printer, as in the first embodiment, the following description mainly focuses on the differences from the first embodiment. explain.
As shown in FIG. 4A, the valve unit 119 in the present embodiment includes a flow path forming member 133 having a regular shape. A substantially frustoconical recess 133a is formed on one side of the flat surface of the flow path forming member 133 (upper surface in the figure), and the opening of the recess 133a is sealed in a predetermined bent state. A partition film 137 as a flexible member is stuck by heat welding so as to stop. And the pressure chamber 139 is comprised by the internal space enclosed and formed by this partition film 137 and the recessed part 133a. A disc-shaped pressure receiving plate 138 is attached to the central portion of the upper surface of the partition film 137 constituting a part of the wall surface of the pressure chamber 139 so as to be concentrically arranged with respect to the recess 133a.

  On the other hand, on the other surface side of the flow path forming member 133 (the lower surface side in FIG. 4A), an ink supply chamber 133b having an inner surface having a cylindrical surface is formed in a substantially central portion, and this ink is formed. The film member 100 is heat-sealed so as to seal the lower surface side opening of the supply chamber 133b. An inflow path 119a is formed in the flow path forming member 133 so as to open a downstream end in the ink supply chamber 133b.

  In the flow path forming member 133, a support hole 133d is formed at the center of the partition portion 133c that partitions the pressure chamber 139 and the ink supply chamber 133b. A valve member 144 is slidably supported in the support hole 133d. The valve member 144 includes a plate-like portion 144a located in the ink supply chamber 133b, and a rod portion 144b that is formed integrally with the central portion of the plate-like portion 144a and whose tip extends into the pressure chamber 139 through the support hole 133d. It is comprised by.

  In the ink supply chamber 133b, a spring seat 101 is attached to the wall surface constituted by the film member 100, and a coiled valve biasing spring is provided between the plate-like portion 144a and the spring seat 101. 146 is interposed in a contracted power storage state. On the other hand, a rubber seal member 102 formed in an annular shape so as to surround the support hole 133d is attached to the partition portion 133c by thermal welding or the like. Therefore, the plate-like portion 144a of the valve member 144 abuts on the seal member 102 by the urging force of the valve urging spring 146, and is urged toward the partition portion 133c side with a slight pressing force.

  A notch hole 133e is intermittently formed along the periphery of the support hole 133d in the support hole 133d formed in the partition part 133c. Each of the cutout holes 133e is located inside the seal member 102, and the cutout hole 133e and the support hole 133d serve as an inlet 139a to the pressure chamber 139.

  Further, in the flow path forming member 133, the outlet 139b from the pressure chamber 139 is opened on the inner surface of the recess 133a at a position outside the ink supply chamber 133b (on the right side in FIG. 4A). An outflow passage 119b is formed. In this embodiment, the ink supply path (liquid supply path) is configured by the ink supply tube 25, the inflow path 119a, the ink supply chamber 133b, and the outflow path 119b described above.

  A cap-shaped sealing film 140 as a sealing member is attached to the upper side of the flow path forming member 133. That is, the cap-shaped sealing film 140 has the opening edge fitted to the outer surface of the flow path forming member 133, so that the partition film 137 is formed in a predetermined bending state from above the flow path forming member 133. Covered to cover. A liquid filling chamber 142 is formed by filling a nonpolar liquid such as oil in a space surrounded by the sealing film 140 and the partition film 137. That is, the liquid filling chamber 142 is provided outside the pressure chamber 139 so that the partition film 137 forms a partition with the pressure chamber 139. Since the sealing film 140 is attached so as to cover the entire partition film 137 in a predetermined bending state, the area of the wall surface constituted by the partition film 137 in the liquid filling chamber 142 is the sealing film 140. It is smaller than the area of the constructed wall.

Next, the operation of the valve unit 119 configured as described above will be described.
First, prior to printing, the printer discharges or sucks ink from the nozzles with the recording head 18 disposed at the home position HP as a preparatory work, so that the inflow path 19a and the ink on the downstream side of the ink supply tube 25 are formed. The supply chamber 133b, the pressure chamber 139, the outflow path 119b, the ink flow path 18a, and the ink chamber R are filled with ink.
In the state of this preparatory work, the urging force by the valve urging spring 146 in the valve unit 119 is applied to the plate-like portion 144a in the valve member 144. When the pressurizing pump 28 is driven, pressurized air is sent to the pressurizing chamber 32 in the ink cartridge 22, and the ink in the ink pack 24 is sent to the valve unit 19 side in a pressurized state. When the pressurized ink reaches the ink supply chamber 133b through the ink supply tube 25 and the inflow path 119a, the pressure of the pressure-fed ink is also applied to the plate-like portion 144a. Therefore, due to the urging force of the valve urging spring 146 and the pressure of the ink, the plate-like portion 144a is in the closed state in contact with the seal member 102 as shown in FIG. The upstream side and the downstream side are out of communication.

  When the piezoelectric element is driven in this state and ink is ejected from the nozzle 20, the ink in the pressure chamber 139 is supplied to the ink chamber R, and the ink in the pressure chamber 139 decreases. As the ink decreases, the partition film 137 is displaced toward the recess 133 a formed in the flow path forming member 133, and the central portion of the partition film 137 comes into contact with the end portion of the rod portion 144 b of the valve member 144. As the ink is further consumed in the recording head 18, a negative pressure is generated in the pressure chamber 139. When the negative pressure becomes larger than a predetermined pressure (= the urging force of the valve urging spring 146 + the pressure of the ink), the partition film 137 presses the rod portion 144b, whereby the sealing member 102 formed by the plate-like portion 144a. Is released, and the valve is opened as shown in FIG. As a result, the ink supply chamber 133b and the pressure chamber 139 are in communication with each other in the valve unit 119.

  When the valve is opened, the ink in the ink supply chamber 133b is supplied from the ink supply chamber 133b to the pressure chamber 139 through the inlet 139a, and the negative pressure in the pressure chamber 139 is eliminated by the inflow of ink into the pressure chamber 139. Is done. As a result, the valve member 144 moves to the original position and is closed again as shown in FIG. 4A, and the supply of ink from the ink supply chamber 133b to the pressure chamber 139 is stopped.

Therefore, also in the second embodiment as described above, the same effect as that of the first embodiment is achieved.
The above embodiment may be changed to another embodiment as described below.

In each embodiment, each valve unit has one pressure chamber and one liquid filling chamber, but a plurality of pressure chambers may share one liquid filling chamber.
In each embodiment, the liquid filling chamber may be filled with a polar liquid such as water. In this case, although the amount of external air dissolved into the liquid in the liquid filling chamber through the sealing film increases, the air does not move directly into the pressure chamber, so that the growth of bubbles in the pressure chamber is suppressed. be able to.

In each embodiment, the liquid filling chamber is filled with a nonpolar liquid, but the inside may be filled with a low polarity liquid.
In each embodiment, the liquid filling chamber is filled with the liquid, but the inside may be filled with a gel-like fluid.

  In each embodiment, the case where the liquid ejecting apparatus according to the present invention is applied to an ink jet printer has been described. However, the present invention can be similarly applied to other liquid ejecting apparatuses that are not limited to such a printer. For example, printing apparatuses used for facsimiles, copiers, etc., liquid ejecting apparatuses for ejecting liquids such as electrode materials and coloring materials used in the manufacture of liquid crystal displays, EL displays, or surface-emitting displays, etc., and biochip manufacturing It may be a liquid ejecting apparatus for ejecting a bioorganic material to be produced, a sample ejecting apparatus as a precision pipette, or the like.

1 is a schematic plan view of an ink jet printer according to an embodiment. FIG. 2 is a schematic diagram illustrating an ink supply system of a printer according to an embodiment. The valve unit in 1st Embodiment is sectional drawing which shows the case where (a) is a valve closing state, (b) is a valve opening state. The valve unit in 2nd Embodiment is sectional drawing which shows the case where (a) is a valve closing state, (b) is a valve opening state.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Printer as a liquid ejecting apparatus, 18 ... Recording head as a liquid ejecting head, 19, 119 ... Valve unit, 19a, 119a ... Inflow path constituting liquid supply path, 19b, 119b ... Outflow constituting liquid supply path Path, 22 ... ink cartridge as liquid container, 25 ... ink supply tube constituting liquid supply path, 37, 137 ... partition film as flexible member, 39, 139 ... pressure chamber, 39a, 139a ... inflow port 39b, 139b ... outlet, 40,140 ... sealing film as a sealing member, 42, 142 ... liquid filling chamber.

Claims (4)

A pressure chamber provided in the middle of the liquid supply path, and having an inlet for allowing liquid to flow in from the upstream side of the liquid supply path and an outlet for discharging liquid to the downstream side of the liquid supply path;
A flexible member that constitutes a part of the wall surface of the pressure chamber and is displaced based on pressure fluctuation in the pressure chamber;
A liquid filling chamber that is provided outside the pressure chamber so as to form a partition wall with the pressure chamber by the flexible member, and whose inside is filled with a liquid ;
The liquid filling chamber is configured such that at least a part of a wall surface other than the flexible member is configured by a flexible sealing member, and the wall surface portion of the liquid filling chamber is configured by the flexible member. The valve unit is smaller than the area of the wall surface portion of the liquid filling chamber constituted by the sealing member . The valve unit according to claim 1, wherein the inside of the liquid filling chamber is filled with a nonpolar liquid. Wall surface of at least a portion is formed the liquid-filled chamber in the sealing member, to claim 1 or 2, characterized in that provided at a position facing the flexible member across the liquid-filled chamber The valve unit described. A liquid container for containing a liquid;
A liquid ejecting head capable of ejecting the liquid onto a target;
A liquid supply path for supplying the liquid from the liquid container side to the liquid jet head side;
A liquid ejecting apparatus characterized by comprising a valve unit according to any one of claims 1-3.

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