JP2017061055A - Damper device, liquid supply system equipped with the same, and ink jet type recording device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a damper device capable of stably discharging a liquid from a discharge head.SOLUTION: A damper device is equipped with: a hollow case body 21 having an outer wall formed with an opening portion 21b; an expanding/contracting member 22 which is attached to the case body 21 so as to cover the opening portion 21b, and can expand/contract in direction coming close to and separating from the opening portion 21b; a first storage chamber 25; a second storage chamber 26; a valve member 24 inserted into the opening portion 21b; energizing members 24c and 28 which energizes the valve member 24 in a direction blocking the opening portion 21b; and a pressure receiving plate 27 which is attached to the expanding/contracting member 22, and can slide in direction coming close to and separating from the opening portion 21b with the expansion/contraction of the expanding/contracting member 22. When the expanding/contracting member 22 is contracted to a side coming close to the opening portion 21b by a predetermined amount or more, with the decrease of pressure in the second storage chamber 26, the pressure receiving plate 27 presses the valve member 24 to open the opening portion 21b.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a damper device disposed in a liquid supply path that supplies liquid from a liquid supply unit to a liquid discharge unit, a liquid supply system including the damper device, and an ink jet recording apparatus.

  In an inkjet recording apparatus for business use or the like, a so-called off-carriage system is adopted in which a large-capacity ink cartridge is disposed away from a carriage on which an ink discharge head is mounted. In an off-carriage type recording apparatus, an ink supply path for supplying ink from an ink cartridge to an ink discharge head is generally long. As a result, ink pressure fluctuations increase in the ink supply path, and ink may not be stably ejected from the ink ejection head.

  In view of this, conventionally, it has been studied to suppress ink pressure fluctuations to be small. For example, Patent Document 1 discloses a configuration in which an ink discharge head and a damper device are mounted on a carriage. The damper device has a function of adjusting the pressure of ink supplied to the ink discharge head (self-sealing function). Therefore, according to the above configuration, ink can be supplied to the ink ejection head with a predetermined pressure, and ink can be ejected stably.

International Publication No. 2003/041964 Pamphlet

  The damper device described in Patent Document 1 has a pressure chamber for temporarily storing ink. One wall surface of the pressure chamber is made of a flexible film. The pressure chamber becomes negative pressure when the amount of ink stored decreases. The flexible film is bent and deformed based on the negative pressure. When the flexible film is bent and deformed, the displacement is directly transmitted to a valve connected to the flexible film. Thereby, the valve structure of the damper device is opened and closed. However, in such a configuration, the movable range of the flexible film is greatly limited. That is, the flexible film is configured to be displaceable only in a narrow region based on the bending deformation. For this reason, the damper device of Patent Document 1 has a problem in that the supply of ink to the ink ejection head cannot catch up when, for example, a large amount of ink is consumed at one time. As a result, there is a risk that the ink ejection becomes unstable or an unexpected ejection failure occurs. On the other hand, if the printing speed is slowed down so that the supply of ink catches up, there is a risk that the throughput will decrease.

  The present invention has been made in view of such a point, and an object thereof is to provide a damper device capable of stable operation even when a large amount of liquid is discharged at one time. Another related object is to provide a liquid supply system including the damper device and an ink jet recording apparatus.

  The damper device according to the present invention is disposed in a liquid supply path that supplies liquid from the liquid supply unit to the liquid discharge unit. The damper device includes a hollow case main body having an outer wall in which an opening is formed, and an expansion / contraction that is attached to the case main body so as to cover the opening, and can extend and contract in a direction approaching and moving away from the opening. A member, a first storage chamber formed in the hollow portion of the case body, and the first storage chamber through the opening, and at least a part thereof is partitioned by the outer wall and the elastic member. A second storage chamber, a liquid inflow port formed in the case body and communicating with the first storage chamber, a liquid outflow port formed in the case body and communicating with the second storage chamber, and the case body A valve member inserted into the opening so as to penetrate the outer wall, a biasing member that biases the valve member in a direction to close the opening, and an expansion / contraction member attached to the expansion / contraction member. And a slidable pressure plate in the direction and away from the direction of approach to the above opening I. And when the said expansion-contraction member shrink | contracts more than the predetermined amount to the side which approaches the said opening part with the reduction | decrease of the pressure of the said 2nd storage chamber, the said pressure receiving plate will push the said valve member and open the said opening part. It is configured.

  In the damper device, the volume of the second storage chamber can be greatly changed by the elastic member. Therefore, even when a large amount of liquid is consumed at once, the liquid is quickly supplied from the damper device to the ejection head. Thereby, it is possible to stably discharge the liquid from the discharge head while maintaining the throughput.

  According to a preferred aspect of the present invention, the elastic member has a bellows shape.

  According to another preferred embodiment of the present invention, the elastic member has a paunch shape.

  According to another preferable aspect of the present invention, the elastic member includes a gas barrier layer containing an ethylene-vinyl alcohol copolymer.

  According to the said aspect, the gas barrier property, mechanical strength, and durability of an expansion-contraction member can be improved. Therefore, it is possible to highly suppress the bubbles from being mixed into the liquid in the second storage chamber and discharge the liquid from the discharge head more stably. In addition, the life of the damper device can be extended.

  According to another preferred embodiment of the present invention, the stretchable member includes a polyolefin layer containing a polyolefin-based resin on both surfaces of the gas barrier layer.

  According to the said aspect, when the liquid which distribute | circulates is an ink, ink corrosion resistance can be improved. The polyolefin layer can function as a so-called adhesive layer. Therefore, attachment of the elastic member to the case body and attachment of the pressure receiving plate to the elastic member can be easily performed via the polyolefin layer. Therefore, it is possible to reduce the number of parts and simplify the configuration.

  According to another preferred aspect of the present invention, the surface of the portion of the pressure receiving plate that is connected to the elastic member is formed of a polyacetal resin.

  According to the said aspect, an expansion-contraction member and a pressure receiving plate can be joined more firmly. For this reason, durability of both can be improved and durability can be improved.

  According to another preferable aspect of the present invention, the biasing member is disposed at a tip portion of the valve member on the first storage chamber side, and has a first magnetic body having a predetermined magnetic pole, and the first member. The first magnetic body is disposed at a position facing the first magnetic body, and the second magnetic body having a repulsive magnetic pole is provided. And it is comprised so that the said valve member may be urged | biased by the reaction force which acts between the said 1st magnetic body and the said 2nd magnetic body.

  According to the said aspect, the influence of the friction of a fluid (liquid) can be suppressed better and the closed state of an opening part can be maintained stably.

  According to another preferable aspect of the present invention, the second magnetic body is disposed outside the first storage chamber.

  According to the said aspect, it can prevent that a 2nd magnetic body is corroded by a liquid, and can improve durability of a biasing member.

  According to another preferable aspect of the present invention, the pressure receiving plate is a recess formed such that a tip end portion of the valve member on the second storage chamber side can be inserted into a position where the pressure receiving plate is connected to the valve member. It has.

  According to the said aspect, a pressure receiving plate and a valve member contact | abut more stably. For this reason, the valve member can be moved at a stable timing based on the expansion / contraction of the expansion / contraction member, and the opening can be opened in a timely and accurate manner.

  According to another preferable aspect of the present invention, a notch groove is formed on the inner side surface of the opening portion along a direction parallel to the movable direction of the valve member.

  According to the said aspect, even when a valve member is not located in the approximate center of an opening part, for example, a liquid moves stably along a notch groove. For this reason, the flow of the liquid can be made relatively uniform, and the liquid can be moved smoothly.

  As another aspect of the present invention, a liquid supply system is provided. The liquid supply system includes a liquid supply unit that stores liquid, a liquid discharge unit that discharges liquid, a liquid supply path that has one end communicating with the liquid supply unit, and the other end communicating with the liquid discharge unit, And the damper device disposed in the liquid supply path.

  According to a preferred aspect of the present invention, the liquid ejection unit and the damper device are mounted on a carriage so as to be capable of reciprocating in a predetermined scanning direction.

  According to the said aspect, the dynamic pressure concerning a liquid discharge part can be absorbed immediately before discharge. For this reason, the liquid discharge stability can be further enhanced.

  As another aspect of the present invention, an ink jet recording apparatus including the liquid supply system is provided.

  According to the damper device of the present invention, even when a large amount of liquid is discharged at a time, the liquid is quickly supplied to the discharge head. Thereby, it is possible to stably discharge the liquid from the discharge head while maintaining the throughput.

1 is a front view of an ink jet printer according to an embodiment of the present invention. FIG. 2 is a partial perspective view of the ink jet printer shown in FIG. 1. It is a front view of the damper device concerning one embodiment of the present invention. It is the IV-IV line longitudinal cross-sectional view of the damper apparatus shown in FIG. It is a figure which shows the state by which the opening part of FIG. 4 was open | released. FIG. 6 is a cross-sectional view taken along line VI-VI of the damper device shown in FIG. 4. It is a longitudinal cross-sectional view of the damper apparatus which concerns on other one Embodiment of this invention.

  Hereinafter, embodiments of a damper device, a liquid supply system, and an ink jet recording apparatus according to the present invention will be described with reference to the drawings as appropriate. The embodiments described herein are, of course, not intended to limit the present invention in particular. Further, members / parts having the same action are denoted by the same reference numerals, and redundant description is omitted or simplified.

  FIG. 1 is a front view of an ink jet printer (hereinafter referred to as a printer) 10 according to an embodiment of the present invention. In FIG. 1 and FIG. 2, symbols L and R indicate left and right, respectively. In FIG. 1, the near side and the far side are the front side and the rear side, respectively. However, these are only directions for convenience of explanation, and do not limit the installation mode of the printer 10 at all.

  The printer 10 is an example of an ink jet recording apparatus. The printer 10 is for printing on the recording paper 5 which is a recording medium. The recording media include not only paper such as plain paper, but also recording media made of various materials such as resin materials such as polyvinyl chloride (PVC) and polyester, aluminum, iron, and wood. It is.

  The printer 10 includes a printer main body 2 and a guide rail 3 fixed to the printer main body 2. The guide rail 3 extends in the left-right direction. The carriage 1 is engaged with the guide rail 3. Rollers (not shown) are respectively provided on the left end side and the right end side of the guide rail 3. A carriage motor (not shown) is connected to one of these rollers. This one roller is rotationally driven by a carriage motor. An endless belt 6 is wound around both rollers. The carriage 1 is fixed to the belt 6. When the roller rotates and the belt 6 travels, the carriage 1 moves in the left-right direction. Thus, the carriage 1 reciprocates in the left-right direction along the guide rail 3.

  The printer main body 2 is provided with a platen 4 that supports the recording paper 5. The platen 4 is provided with a pair of upper and lower grid rollers and a pinch roller (not shown). The grid roller is connected to a feed motor (not shown). The grid roller is driven to rotate by a feed motor. When the grid roller rotates while the recording paper 5 is sandwiched between the grid roller and the pinch roller, the recording paper 5 is conveyed in the front-rear direction.

  The printer main body 2 includes a plurality of so-called ink cartridges 11. The ink cartridge 11 is a tank (liquid supply unit) that stores ink. Specifically, a plurality of ink cartridges 11C, 11M, 11Y, 11K, and 11W are detachably attached to the printer main body 2. Cyan ink is stored in the ink cartridge 11C. Magenta ink is stored in the ink cartridge 11M. Yellow ink is stored in the ink cartridge 11Y. Black ink is stored in the ink cartridge 11K. White ink is stored in the ink cartridge 11W. An ink outlet (not shown) is attached to each of the ink cartridges 11C, 11M, 11Y, 11K, and 11W.

  The printer 10 has an ink supply system for each color ink cartridge 11C, 11M, 11Y, 11K, and 11W. The ink supply system includes a damper device 14, an ink discharge head (liquid discharge unit) 15, and an ink supply path (liquid supply path) 16. In the present embodiment, a supply pump 13 and a control device 18 are further provided. The ink discharge head 15 and the damper device 14 are mounted on the carriage 1 and reciprocate in the left-right direction. On the other hand, the ink cartridge 11 is not mounted on the carriage 1 and does not reciprocate in the left-right direction. For this reason, most of the ink supply path 16 (at least half of the total length) is arranged extending in the left-right direction so that the ink supply path 16 is not damaged even if the carriage 1 moves in the left-right direction. In this embodiment, since five types of ink are used, a total of five ink supply paths 16 are provided. These ink supply paths 16 are covered with a cable protection guide device 7. The cable protection guide device 7 is, for example, a cable bear (registered trademark).

  Hereinafter, as an example, an ink supply system provided in an ink cartridge 11C that stores cyan ink will be described. FIG. 2 is a partial perspective view of the printer 10. In FIG. 2, symbols F and Rr indicate front and rear, respectively.

  The ink discharge head 15 is an example of a liquid discharge unit that discharges ink toward the recording paper 5. A plurality of nozzles (not shown) for discharging ink are formed on the lower surface of the ink discharge head 15. An actuator (not shown) made of a piezoelectric element or the like is provided inside the ink discharge head 15. When this actuator is driven, ink is ejected from the nozzle.

  The ink cartridge 11 </ b> C and the ink discharge head 15 communicate with each other through an ink supply path 16. The ink supply path 16 forms a flow path for guiding ink from the ink cartridge 11 </ b> C to the ink discharge head 15. The ink supply path 16 has flexibility and flexibility so that it can be applied to the movement of the carriage 1. The configuration of the ink supply path 16 is not particularly limited. For example, the ink supply path 16 is a resin-made easily deformable tube. However, it may be made of a material other than the tube.

  The supply pump 13 is provided in the ink supply path 16. The supply pump 13 is an example of a liquid feeding device that supplies ink from the ink cartridge 11 </ b> C toward the ink discharge head 15. The kind of supply pump 13 is not particularly limited. The supply pump 13 is, for example, a so-called tube pump of a trochoid pump type. The supply pump 13 is connected to the control device 18. The driving and stopping of the supply pump 13 are controlled by the control device 18.

  The control device 18 controls the supply of ink from the ink cartridge 11 </ b> C to the ink ejection head 15. The control device 18 is typically a computer, and includes a central processing unit (CPU) that executes instructions of the control program, a ROM (read only memory) that stores a program executed by the CPU, and a program. A random access memory (RAM) used as a working area to be developed and a storage device (recording medium) such as a memory for storing the program and various data are provided.

  The damper device 14 is provided in the ink supply path 16. FIG. 3 is a front view of the damper device 14 according to the embodiment of the present invention. 4 is a vertical sectional view taken along line IV-IV of the damper device 14 shown in FIG. FIG. 5 is a view showing a state in which the opening 21b of FIG. 4 is opened. The damper device 14 communicates with the ink discharge head 15 and plays a role of supplying ink to the ink discharge head 15. The damper device 14 also has a role of stabilizing the ink ejection operation of the ink ejection head 15 by relaxing ink pressure fluctuation during printing (for example, during ink ejection). Since the damper device 14 communicates with the ink discharge head 15, dynamic pressure can be absorbed immediately before ink discharge. For this reason, the liquid discharge stability can be further enhanced.

  The damper device 14 of this embodiment includes a case main body 21 and an elastic member 22 attached to the wall surface of the case main body 21. As shown in FIG. 3, an ink inlet 20a through which ink flows is formed on one wall surface (the right wall surface in FIG. 3) of the case body 21. As shown in FIG. The ink inlet 20a is connected to the ink supply path 16 and communicates with the ink cartridge 11C. An ink outlet 29a through which ink flows out is formed on one wall surface of the case body 21 (the lower wall surface in FIGS. 3 and 4). The ink outlet 29 a is connected to the ink supply path 16 a and communicates with the ink discharge head 15. As shown in FIG. 4, the case main body 21 has a hollow structure. The case main body 21 has an outer wall in which an opening 21b connected to the hollow portion is formed. The elastic member 22 is attached to the outer wall surface of the case body 21 so as to cover the opening 21 b of the case body 21.

  The case body 21 is typically made of resin. In this embodiment, the case main body 21 is formed in a flat rectangular parallelepiped shape. The case main body 21 and the expansion / contraction member 22 form an ink storage chamber for temporarily storing ink. The ink storage chamber is divided into two space regions (a first storage chamber 25 and a second storage chamber 26) by a wall provided in the opening 21 b of the case body 21. In other words, the wall on the side of the opening 21 b of the case body 21 serves as the partition wall 21 a that separates the first storage chamber 25 and the second storage chamber 26. A hollow space region formed inside the case body 21 is the first storage chamber 25. The first storage chamber 25 is communicated with the ink inflow port 20 a by the inflow side passage 20. A space region surrounded by the outer wall surface of the case body 21 and the elastic member 22 is a second storage chamber 26. The 1st storage chamber 25 and the 2nd storage chamber 26 are connected via the opening part 21b. The second storage chamber 26 is communicated with the ink outlet 29 a by the outflow side passage 29. The ink that has flowed from the ink inflow port 20 a passes through the inflow side passage 20 and flows into the first storage chamber 25 from the opening end 20 b of the inflow side passage 20. The ink in the first storage chamber 25 moves to the second storage chamber 26 when the valve member 24 moves. The ink in the second storage chamber 26 flows out from the ink outlet 29 a through the outflow side passage 29.

  The second storage chamber 26 includes a part of the wall surface made of the elastic member 22. The volume of the second storage chamber 26 varies greatly as the telescopic member 22 expands and contracts. For example, as compared with the case where the wall surface of the second storage chamber 26 is formed of a flexible film, the second storage chamber 26 varies relatively greatly. Thus, even if it exists in the aspect which consumes a lot of ink at once by changing the volume of the 2nd storage chamber 26 notably large, it can cope suitably. Therefore, the effect of the present invention is exhibited at a higher level.

  Incidentally, in general, in a damper device including a valve member, the ink liquid level in the ink storage chamber is equal to or higher than the height of the valve member from the viewpoint of accurately moving the valve member when the pressure in the ink storage chamber becomes negative. It is desirable to arrange them at higher positions. Therefore, when ink is initially filled in the ink supply system, when the ink reaches the damper device, the ink inlet side of the damper device is temporarily closed, and the ink outlet side (typically the ink discharge head) is closed. Suction is performed from the lower surface using a pump. When the ink inlet is opened in a state where the pressure in the ink storage chamber is reduced to some extent, a large amount of ink flows into the ink storage chamber at once. In this way, the ink storage chamber is filled with ink as much as possible, and the ink liquid level is made higher.

Here, in the damper device 14 shown in FIG. 3, the valve member 24 is positioned at the approximate center in the height direction in the ink storage chamber. Therefore, in order to arrange the ink liquid level in the second storage chamber 26 at a position equal to or greater than that of the valve member 24, the volume of the second storage chamber 26 when the expansion / contraction member 22 extends to a predetermined maximum elongation value is set. When V ₁ is set and V ₂ is the volume of the second storage chamber 26 when the expansion / contraction member 22 is contracted to a predetermined maximum contraction value, it is necessary to satisfy (V ₁ −V ₂ )> V _1/2. . When this equation is arranged, the volume (V ₁ −V ₂ ) of the second storage chamber 26 can be changed greatly as V ₁ is increased (V ₂ is decreased), and a large amount of ink is stored in the storage chamber. I can say that. Therefore, according to the configuration provided with the elastic member 22 disclosed herein, for example, an advantageous condition at the time of ink filling can be obtained as compared with a case where a flexible film having a movable range only for bending deformation is used. Can be produced.

  The expansion / contraction member 22 is configured to be expandable / contractible in the perspective direction of the opening 21b of the case main body 21, that is, the direction approaching and moving away from the opening 21b, according to the pressure in the second storage chamber 26. . More specifically, when the ink stored in the second storage chamber 26 decreases and the inside of the second storage chamber 26 reaches a certain negative pressure, the second storage chamber 26 is configured to contract toward the opening 21b. In the present embodiment, the elastic member 22 includes a planar portion 22a disposed substantially parallel to the partition wall 21a, and two gusset portions 22b and 22c that connect the partition wall 21a and the planar portion 22a. . The gusset portions 22b and 22c have a vertically sectional shape that is symmetrical in the vertical direction. As these gussets 22b and 22c expand and contract in an accordion shape, the expandable member 22 expands and contracts in the perspective direction of the partition wall 21a. Here, the elastic member 22 has a bellows shape. Thereby, compared with the case where a flexible film as described, for example in patent document 1 is used, the movable range of the expansion-contraction member 22 spreads largely comparatively. In other words, a large volume change or pressure change can be brought about in the second storage chamber 26 by the stretchability unique to the stretchable member 22. As a result, a large amount of ink can be supplied to the ink ejection head 15 at a stretch.

  The stretchable member 22 has almost no flexibility like a flexible film due to its structure. On the other hand, the flexible film is so soft that it can be bent and deformed, and conversely, has no stretchability like the stretchable member 22. For example, the spring constant of the flexible film is approximately 10 g / mm or less, whereas the elastic member 22 is approximately 20 g / mm or more, for example, about 50 to 70 g / mm. Note that the spring constant represents a load necessary to dent the central portion of the elastic member 22 or the flexible film without the valve member 24 by 1 mm. Moreover, the average thickness of a flexible film is about 70 micrometers or less, typically about 30-50 micrometers. On the other hand, the elastic member 22 is typically thicker than the flexible film, and the average thickness is approximately 100 μm or more, typically 150 μm or more, for example, about 200 to 400 μm. Thus, the properties of the elastic member 22 and the flexible film are completely different.

  The elastic member 22 is good in gas barrier property. When a gas component such as air is mixed through the elastic member 22, bubbles are generated in the second storage chamber 26. If the bubbles flow into the ink discharge head 15, the ink cannot be discharged, and printing failure or the like may occur. For this reason, it is preferable that the elastic member 22 has low gas permeability and water vapor permeability. The surface of the elastic member 22 on the side in contact with ink is preferably excellent in ink corrosion resistance. For the reasons described above, a resin film having a multilayer structure is suitable as the elastic member 22. In this embodiment, a resin film having a three-layer structure is adopted as the elastic member 22.

  The intermediate layer of the resin film having a three-layer structure is a gas barrier layer containing an ethylene-vinyl alcohol copolymer (EvOH resin). By containing the EvOH resin in the elastic member 22, the gas barrier property, mechanical strength, and durability of the elastic member 22 can be improved. The average thickness of the gas barrier layer is preferably about 30 to 70 μm. The gas barrier layer is sandwiched between polyolefin layers containing a polyolefin resin. The surface of the resin film on the side in contact with the second storage chamber 26 is made of polypropylene resin (PP) having excellent ink corrosion resistance. Further, the surface on the other side of the resin film (the surface in contact with the outside) is made of polyethylene resin (PE). The polyolefin layer can function as a so-called adhesive layer when the elastic member 22 and another member (for example, the case main body 21 or the pressure receiving plate 27) are joined. This is preferable from the viewpoint of reducing the number of parts and simplifying the configuration.

  The pressure in the second storage chamber 26 of the damper device 14 and the pressure of the nozzles of the ink discharge head 15 are substantially equal. For this reason, the surface opposite to the second storage chamber 26 side of the elastic member 22 (the outer surface of the damper 14) is preferably in contact with the atmosphere. According to the above configuration, the pressure on the outer surface of the elastic member 22 automatically changes according to the change in atmospheric pressure. Accordingly, it is possible to accurately prevent ink from leaking from the nozzles without performing complicated control. In addition, ink can be smoothly ejected from the nozzles during printing.

  A valve member (valve rod) 24 is inserted into the opening 21b. The valve member 24 is configured to move in conjunction with the displacement of the pressure receiving plate 27 attached to the expandable member 22 (the amount of sliding toward the side closer to the opening 21b). By moving the valve member 24, the valve member 24 and the partition wall 21a are brought into a contact state or a non-contact state. Thereby, the opening part 21b will be in a closed state or an open state. In the present embodiment, the valve member 24 includes a valve body 24a having a vertical cross-sectional shape of “T” and a seal portion 24b.

  The valve body 24 a is inserted into the opening 21 b so as to penetrate the partition wall 21 a of the case body 21. The valve main body 24a extends from the first storage chamber 25 to the second storage chamber 26 through the opening 21b. The portion inserted into the opening 21b of the valve main body 24a is an elongated rod (long axis shape), and has an outer diameter smaller than the inner diameter of the opening 21b. The part arrange | positioned inside the 1st storage chamber 25 of the valve main body 24a has an outer diameter larger than the internal diameter of the opening part 21b. The valve body 24a may be excellent in ink corrosion resistance. The valve body 24a is typically made of resin.

  6 is a cross-sectional view taken along line VI-VI of the damper device 14 shown in FIG. That is, FIG. 6 shows a cross section of the partition wall 21 a portion of the case body 21. In the present embodiment, the partition wall 21a portion of the case body 21 has a substantially circular cross-sectional shape. The opening 21b has a substantially circular cross-sectional shape smaller than the partition wall 21a. A valve main body 24a of the valve member 24 is inserted in a substantially central part of the cross section of the opening 21b. The valve body 24a has a substantially circular cross-sectional shape that is slightly smaller than the opening 21b. A gap between the valve main body 24a and the inner side surface of the opening 21b is an ink flow path. Three cutout grooves 21c are formed on the inner side surface of the opening 21b. The notch groove 21c is formed along the direction in which the valve member 24 is movable, that is, the direction parallel to the major axis direction of the valve body 24a. The ink can move along the notch groove 21c when the opening 21b is opened. For example, in FIG. 6, when the position of the valve body 24a is biased to the right side, the ink flow path becomes smaller on the right side and larger on the left side. Therefore, when there is no notch groove 21c, the ink passes exclusively through the left side of the valve body 24a, and the ink flow becomes non-uniform. However, since the cutout groove 21c is provided in the present embodiment, even in such a case, a part of the ink flows through the cutout groove 21c on the right side, and the ink flow is made relatively uniform.

  The seal portion 24b of the valve member 24 is interposed between the valve main body 24a and the partition wall 21a. In the present embodiment, the seal portion 24b is provided in an annular shape (O-ring shape) at the periphery of the portion arranged in the first storage chamber 25 of the valve body 24a. The seal portion 24b of the valve member 24 functions so as to be in close contact with the partition wall 21a and to close the opening portion 21b accurately. The seal portion 24b may be made of an elastic material. The seal portion 24b may be excellent in ink corrosion resistance. In the present embodiment, the seal portion 24b is made of rubber.

  The urging member functions to urge the valve member 24 in a direction to close the opening 21b. In this embodiment, a pair of magnetic bodies is used as the biasing member. The first magnetic body 24c is disposed at the tip of the valve member 24 on the first storage chamber 25 side. The first magnetic body 24c has a predetermined magnetic pole. The second magnetic body 28 is disposed at a position facing the first magnetic body 24c. The second magnetic body 28 is disposed outside the first storage chamber 25 (the outer wall surface of the case body 21). By disposing the second magnetic body 28 outside the first storage chamber 25, contact with ink is prevented. Thereby, the magnetic force fall by corrosion can be suppressed and durability can be improved. In addition, there is an effect that the first storage chamber 25 has a larger volume, the flow resistance is reduced, and the ink flow is made smooth. The second magnetic body 28 has the same magnetic pole as the first magnetic body 24c. By arranging the magnetic bodies having the same magnetic poles to face each other, a reaction force acts between the first magnetic body 24c and the second magnetic body 28. Thereby, the seal part 24b of the valve member 24 is pressed against the partition wall 21a. That is, the valve member 24 is biased in the direction of closing the opening 21b by the reaction force between the first magnetic body 24c and the second magnetic body 28.

  The magnetic bodies 24c and 28 are not particularly limited. For example, a permanent magnet such as a neodymium magnet or an electromagnet may be used. In the present embodiment, strong neodymium magnets are employed as the magnetic bodies 24c and 28. On the outside of the second magnetic body 28, a cover body 30 having a substantially “U” shape in longitudinal section is provided. The cover body 30 is attached to the surface opposite to the surface on which the elastic member 22 of the case body 21 is attached (the left surface in FIG. 4).

  In the damper device described in Patent Document 1 and the like, a seal spring is used as a biasing member that biases the valve body in the closing direction. However, when a seal spring is used, there is a problem that it is easily affected by ink friction. For example, when a large amount of ink is consumed at once, the closed state may not be properly maintained if the ink flow pressure becomes high. Further, when the seal spring is corroded and deteriorated due to long-term use, the urging force may be weakened and ink discharge from the ink discharge head may become unstable. However, since it is not necessary to use a seal spring in this embodiment, such a problem can be prevented. Furthermore, the influence of ink friction can be better suppressed, and the closed state of the opening 21b can be stably maintained.

  A pressure receiving plate 27 is attached to the planar portion 22 a of the elastic member 22. The pressure receiving plate 27 is configured to be slidable in the perspective direction of the opening 21 b based on the expansion and contraction of the expansion member 22. Specifically, when the inside of the second storage chamber 26 has a certain negative pressure and the expansion / contraction member 22 contracts by a predetermined amount toward the opening 21b, the second storage chamber 26 moves in the horizontal direction toward the opening 21b accordingly. It is configured. The pressure receiving plate 27 maintains substantially the same shape regardless of the expansion / contraction state of the expansion / contraction member 22. The pressure receiving plate 27 has a relatively large area compared to the tip portion of the valve member 24 on the second storage chamber 26 side. In the present embodiment, the pressure receiving plate 27 has substantially the same area as the partition wall 21 a and the planar portion 22 a of the elastic member 22. In this way, by increasing the area of the pressure receiving plate 27, the pressure receiving area increases, and the accuracy of operation is improved. In the present embodiment, the pressure receiving plate 27 has a substantially disc shape. Here, the entire surface of the pressure receiving plate 27 on the side of the elastic member 22 is attached to the elastic member 22, but only the outer peripheral portion of the pressure receiving plate 27 may be attached to the elastic member 22, for example.

  The pressure receiving plate 27 is preferably harder than the elastic member 22 and relatively light so as not to hinder the displacement of the elastic member 22. The pressure receiving plate 27 is also preferably excellent in ink corrosion resistance. The material of the pressure receiving plate 27 may be further selected in consideration of compatibility with the elastic member 22, for example, ease of joining with the elastic member 22. From such a point, the pressure receiving plate 27 is typically made of resin. In the present embodiment, the pressure receiving plate 27 is made of a polyacetal-based resin excellent in bondability with the polyolefin layer of the elastic member 22. Thereby, the elastic member 22 and the pressure receiving plate 27 are firmly integrated.

  A concave portion 27 a that protrudes outside the second storage chamber 26 is formed at a substantially central portion (central portion) of the pressure receiving plate 27. The recess 27a is provided at a position that can be connected to the tip of the valve member 24 on the second storage chamber 26 side. The recessed part 27a is formed so that the front-end | tip part by the side of the 2nd storage chamber 26 of the valve member 24 can be inserted. Thereby, when the inside of the 2nd storage chamber 26 becomes a negative pressure, the valve member 24 and the pressure receiving plate 27 come to contact | abut stably. Therefore, the valve member 24 can be moved at an appropriate timing, and the opening 21b can be opened in a timely and accurate manner. In the present embodiment, the recess 27a has a substantially dome shape.

  When printing is not performed, that is, when ink is not ejected from the ink ejection head 15, a predetermined amount or more of ink is stored in the second storage chamber 26 of the damper device 14. At this time, the valve member 24 is pressed against the partition wall 21a by the reaction force of the urging members 24c and 28. Thereby, the opening part 21b is maintained in the closed state. In other words, the opening 21b is not opened unless the ink in the second storage chamber 26 is reduced to a predetermined amount and the second storage chamber 26 becomes negative pressure.

  On the other hand, when printing of the printer 10 is started, the supply pump 13 is driven by the control device 18. At the same time, ink is ejected from the nozzles of the ink ejection head 15 toward the recording paper 5. When the ink is discharged, the ink stored in the second storage chamber 26 of the damper device 14 is sucked out and supplied to the ink discharge head 15. As a result, the amount of ink stored in the second storage chamber 26 decreases, and the inside of the second storage chamber 26 becomes negative pressure. As the inside of the second storage chamber 26 becomes negative, as shown in FIG. 5, the two gussets 22b and 22c of the elastic member 22 are on the side of the opening 21b (left side in FIG. 5) so that they are folded in an accordion shape. ). Along with this, the pressure receiving plate 27 attached to the elastic member 22 slides substantially horizontally toward the opening 21b. When the pressure receiving plate 27 slides toward the opening 21b by a predetermined amount or more, the pressure receiving plate 27 and the tip of the valve member 24 on the second storage chamber 26 side are connected substantially vertically. From this state, when the expansion / contraction member 22 is further contracted and the pressure receiving plate 27 is slid toward the opening 21b, the valve member 24 resists the reaction force of the urging members 24c and 28, and is on the side of the first storage chamber 25. Moves when pushed (left side in FIG. 5). Thereby, the seal part 24b of the valve member 24 leaves | separates from the partition 21a, and the opening part 21b is open | released. Then, ink flows from the first storage chamber 25 to the second storage chamber 26. In FIG. 5, the direction of ink flow during printing is indicated by arrows.

  As the ink flows from the first storage chamber 25 into the second storage chamber 26, the negative pressure in the second storage chamber 26 is eliminated. Along with this, the contraction of the elastic member 22 is alleviated, and the pressure receiving plate 27 moves in a direction away from the opening 21b. As a result, the valve member 24 is returned to the second storage chamber 26 side (the right side in FIG. 5) by the reaction force of the urging members 24c and 28. And when the seal part 24b of the valve member 24 contacts the partition wall 21a, the opening part 21b is closed.

  The first storage chamber 25 of the damper device 14 communicates with the ink cartridge 11C. For this reason, the ink reduced in the first storage chamber 25 is appropriately replenished from the ink cartridge 11C. As described above, ink is stably supplied from the ink cartridge 11C to the ink ejection head 15 during printing. In the configuration shown here, the opening 21b is configured to open and close in conjunction with the displacement of the expansion member 22 and the pressure receiving plate 27. Therefore, it is not necessary to electrically control the damper device 14 and it is simple.

  The preferred embodiments of the present invention have been described above. However, the above-described embodiment is merely an example, and the present invention can be implemented in various other forms.

  For example, in the above-described embodiment, the bellows-shaped expansion / contraction member 22 is used for the damper device 14, but the invention is not limited thereto. FIG. 7 is a longitudinal sectional view of a damper device 34 according to another embodiment of the present invention. The damper device 34 according to the present embodiment includes a drum-shaped expansion / contraction member 32. The elastic member 32 includes a planar portion 32a disposed substantially parallel to the partition wall 21a, and two gusset portions 32b and 32c that connect the partition wall 21a and the planar portion 32a. The gusset parts 32b and 32c are arched (bow-shaped) whose cross-sectional shapes are vertically symmetrical. The expansion and contraction member 32 expands and contracts in the perspective direction of the partition wall 21a by the expansion and contraction of these gusset portions 32b and 32c in a substantially "<" shape or an accordion shape. Thus, the same function as when the bellows-shaped elastic member 22 is used can be exhibited.

  In each of the above-described embodiments, the liquid stored in the liquid supply unit (ink cartridge 11) is ink. However, the present invention is not limited to this. The liquid may be, for example, a cleaning liquid used for maintenance of the ink jet recording apparatus.

  In the above-described embodiment, the ink jet recording apparatus is the ink jet printer 10, but the present invention is not limited to this. The ink jet recording apparatus may be any apparatus that can record an image. The ink supply system and the ink jet printer 10 described above include an ink cartridge 11 (liquid supply unit), a supply pump 13, damper devices 14 and 34, an ink discharge head (liquid discharge unit) 15, and an ink supply path ( (Liquid supply path) 16 and control device 18 are provided, but the present invention is not limited to this. For example, the supply pump 13 may be provided as necessary. Alternatively, in addition to the above-described components, a cap that covers the nozzles of the ink discharge head 15 at a time other than printing and a suction pump that sucks the inside of the cap may be further provided.

  In the above-described embodiment, the damper devices 14 and 34 are mounted on the ink jet recording apparatus, but the present invention is not limited to this. The damper devices 14 and 34 can be used in various applications including a liquid supply system, such as various manufacturing apparatuses adopting an ink jet method, measuring instruments such as a micropipette, and the like.

DESCRIPTION OF SYMBOLS 14 Damper apparatus 20a Ink inlet 21 Case main body 21a Partition 21b Opening part 22 Stretching member 24 Valve member 24c, 28 Energizing member 25 1st storage chamber 26 2nd storage chamber 27 Pressure receiving plate 29a Ink outlet

Claims (13)

Arranged in a liquid supply path for supplying liquid from the liquid supply unit to the liquid discharge unit
A hollow case body having an outer wall in which an opening is formed;
An expansion / contraction member attached to the case body so as to cover the opening, and expandable / contractible in a direction approaching and moving away from the opening;
A first storage chamber formed in the hollow portion of the case body;
A second storage chamber communicated with the first storage chamber through the opening, and at least a part of which is partitioned by the outer wall and the elastic member;
A liquid inflow port formed in the case body and communicating with the first storage chamber;
A liquid outlet formed in the case body and communicating with the second storage chamber;
A valve member inserted into the opening so as to penetrate the outer wall of the case body;
A biasing member that biases the valve member in a direction to close the opening;
A pressure receiving plate attached to the elastic member and slidable in a direction toward and away from the opening as the elastic member expands and contracts;
With
The pressure receiving plate pushes the valve member to open the opening when the expansion and contraction member contracts by a predetermined amount or more toward the side approaching the opening as the pressure in the second storage chamber decreases. The damper device.   The damper device according to claim 1, wherein the elastic member has a bellows shape.   The damper device according to claim 1, wherein the elastic member has a bellows shape.   The damper device according to any one of claims 1 to 3, wherein the elastic member includes a gas barrier layer including an ethylene-vinyl alcohol copolymer.   The damper device according to claim 4, wherein the elastic member includes a polyolefin layer containing a polyolefin-based resin on both surfaces of the gas barrier layer.   6. The damper device according to claim 5, wherein a surface of a portion of the pressure receiving plate that is connected to the elastic member is formed of a polyacetal resin. The biasing member is
A first magnetic body disposed at a tip of the valve member on the first storage chamber side and having a predetermined magnetic pole;
A second magnetic body disposed at a position facing the first magnetic body and having a magnetic pole repelling the first magnetic body;
With
It is comprised in any one of Claim 1-6 comprised so that the said valve member might be urged | biased by the reaction force which acts between the said 1st magnetic body and the said 2nd magnetic body. Damper device.   The damper device according to claim 7, wherein the second magnetic body is disposed outside the first storage chamber.   9. The pressure receiving plate according to claim 1, wherein the pressure receiving plate includes a recess formed so that a tip end portion of the valve member on the second storage chamber side can be inserted at a position where the pressure receiving plate is connected to the valve member. The damper apparatus described in any one.   The damper device according to any one of claims 1 to 9, wherein a notch groove is formed on a side surface inside the opening portion along a direction parallel to a movable direction of the valve member. A liquid supply unit;
A liquid ejection part;
A liquid supply path having one end communicating with the liquid supply unit and the other end communicating with the liquid discharge unit;
The damper device according to any one of claims 1 to 10, wherein the damper device is disposed in the liquid supply path and supplies liquid to the liquid discharge unit.
A liquid supply system.   The liquid supply system according to claim 11, wherein the liquid discharge unit and the damper device are mounted on a carriage so as to be reciprocally movable in a predetermined scanning direction.   An ink jet recording apparatus comprising the liquid supply system according to claim 11.

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