JP6914690B2 - Liquid storage mechanism in inkjet recording equipment - Google Patents

Description

The present invention relates to a liquid storage mechanism such as a damper mechanism or a self-sealing valve unit used in an inkjet recording device (printer, plotter, etc.), and particularly a liquid storage mechanism that can be used in a large-sized inkjet recording device. It is about.

Conventionally, an inkjet recording device that records characters and images on a recording medium using an inkjet head that ejects ink from a plurality of nozzles has been known. In this inkjet recording device, while moving the carriage on which the inkjet head is mounted with respect to the recording medium in the main scanning direction, ink is ejected from the nozzles of the inkjet head to print a dot pattern in a predetermined area, and the print width is equal to the print width. There is an apparatus having a structure in which the recording medium is moved by a predetermined amount in the sub-scanning direction after the main scanning of the above is completed, and printing of the entire desired area is performed by repeating these operations. In such an inkjet recording device that prints a dot pattern while moving the inkjet head in the scanning direction, in the case of a structure in which the ink cartridge or the like is not directly mounted on the carriage, the ink supply unit (cartridge, ink tank, etc.) It is necessary to connect the distance to the ink jet head with an ink supply path (ink tube, etc.) to supply ink, and in that case, the ink in the ink supply path moves due to the inertial force generated by the movement of the carriage, and the ink moves. Ink ejection of the inkjet head may become unstable due to the influence of ink pressure fluctuation, ink may leak, or the meniscus of the nozzle opening may be destroyed, which may cause adverse effects such as nozzle omission.
Therefore, it is necessary to keep the ink inside the inkjet head within an appropriate pressure range, and when such an inkjet head is used, the ink ejection part of the print head is from a place where the ink is stored, such as an ink cartridge or an ink tank. Some devices are equipped with a damper mechanism in order to buffer positive and negative pressure fluctuations caused by ink movement in the ink supply path up to and to prevent the ink in the head from being affected.
In this type of damper mechanism, a mechanism having one pressure chamber for the ejection portion of the inkjet head is common, but two pressure chambers are provided for the ink ejection portion of the inkjet head and two pressure chambers are provided. It is known that the damping capacity is improved by communicating the pressure chambers with a communication port and operating the whole as one large pressure chamber (see, for example, Patent Document 1).
It is also known that a valve structure having a self-sealing function is used to block pressure fluctuations on the inkjet head (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2003-220712 Japanese Unexamined Patent Publication No. 2004-142405

In liquid storage mechanisms such as liquid supply damper mechanisms and self-sealing valve units used in inkjet recording devices, it is difficult to design the flow path and mold for the discharge port of the pressure chamber that stores liquids such as ink. It is installed at a position having a predetermined distance in the height direction from the lowest bottom surface, not at the bottom of the pressure chamber, due to reasons such as high cost, low pressure buffering capacity due to insufficient liquid filling, and the like.
Therefore, there is a structural problem that the liquid flow path in the pressure chamber is divided during the liquid discharge operation of ink or the like, which makes it impossible to discharge the liquid and the liquid such as ink remains in the pressure chamber. There is.
If a liquid such as ink remains, color mixing will occur in the pressure chamber when the ink is discharged once and the different types of ink are filled in order to use different types of ink. In addition, if the device is left for a long time after the ink is discharged, problems such as solidification in the path of the ink may occur. To solve this problem, cleaning the path by supplying and discharging the cleaning liquid many times. There is a problem that it takes a long time to complete the process and a large amount of cleaning liquid is required. Further, in the residual cleaning liquid when the cleaning liquid is used, there is a problem that if there is a remaining cleaning liquid, the ink is mixed with the supplied ink, which causes a problem such as an ink ejection failure or a head failure.
An object of the present invention is to solve the above problems.

In order to achieve the above object, the present invention includes pressure chambers 34 and 40 provided between the liquid supply unit 7 on the main body side of the apparatus and the inkjet print head 4 to store the liquid supplied to the inkjet print head 4. In a liquid storage mechanism in an inkjet recording apparatus provided with liquid supply ports 30 and 38 in the pressure chamber and liquid discharge ports 32 and 46 arranged at positions higher than the bottoms of the pressure chambers 34 and 40, the liquid discharge port 32 , 46 are connected to the first flow paths 66, 64 for flowing the liquid in the pressure chambers 34, 40 in the direction of the print head, and one of the second flow paths 68, 70 is connected to the bottom of the pressure chambers 34, 40. The other of the second flow paths 68 and 70 is connected to the first flow paths 66 and 64, and the flow path resistance of the second flow paths 68 and 70 is connected to the first flow path 66. It is characterized in that it is set to be larger than the flow path resistance of, 64.
Further, the present invention is characterized in that the pressure chambers 34 and 40 constitute a damper mechanism for absorbing pressure fluctuations applied to the ink in the inkjet print head 4.
Further, in the present invention, the damper mechanism is composed of a first damper 14 having a pressure chamber 34 and a second damper 16 having a pressure chamber 40, and the first damper 14 and the second damper Each of the pressure chambers 34 and 40 of 16 is composed of a wall surface and flexible films 52 and 54 arranged so as to face the wall surface, and the first flow is applied to the first damper 14 and the second damper 16, respectively. The paths 66, 64 and the second flow paths 68, 70 are provided, and the first flow path 66 of the first damper 14 is composed of a flow path for pressure resistance having a predetermined length, and the first flow path is formed. The first flow path 66 of the damper 14 is connected to the pressure chamber 40 of the second damper 16, and the second flow path 68 of the first damper 14 is connected to the first flow path 66 of the first damper 14. The second flow path 70 of the second damper 16 is connected to the first flow path 64 of the second damper 16.
Further, the present invention is characterized in that the flow path resistance of the second flow path 70 of the second damper 16 is made larger than the flow path resistance of the second flow path 68 of the first damper 14.
Further, the present invention is a damper main body 10 having a partition wall 12 and tubular portions 18 forming recesses on both sides of the partition wall 12 on a carriage on which the inkjet print head 4 is mounted and moves in a main scanning direction across a printing medium. The flexible films 52 and 54 are adhered to both end surfaces of the tubular portion 18 in the axial direction, and pressure chambers 34 and 40 are provided on both side surfaces of the partition wall 12, and the first damper 14 and the second damper 16 are provided. The first damper 14 is provided with a liquid discharge port 32 communicating with the pressure chamber 34 of the damper, and the second damper 16 is provided with a liquid supply port 38 communicating with the pressure chamber 40 of the damper. The damper main body 10 is provided with an upstream connection pipe 26 connected to an ink supply portion on the inkjet recording device main body side and a downstream connection pipe 50 connected to an ink ejection portion of the print head 4, and the first damper 14 is provided with the downstream connection pipe 50. A liquid supply port 30 communicating with the pressure chamber 34 of the damper is provided, a liquid discharge port 46 communicating with the pressure chamber 40 of the damper is provided in the second damper 14, and the liquid supply port 30 of the first damper 14 is provided. The upstream side connecting pipe 26 is connected via a flow path 62 provided in the first damper 14, and the liquid discharge port 46 of the second damper 16 and the downstream side connecting pipe 50 are connected to the second. The liquid discharge port 32 of the first damper 14 and the liquid supply port 38 of the second damper 16 are connected to the first damper 14 via the first flow path 64 provided in the damper 16. The second flow path 68 of the first damper 14 is connected to the first flow path 66 of the first damper 14 by being connected by the first flow path 66 provided, and the second damper 16 is connected. The second flow path 70 is connected to the first flow path 64 of the second damper 16.
Further, in the present invention, the partition wall 12 is provided with a liquid supply port 38 communicating with the pressure chamber 40 of the second damper 16, and a recess extending in the circumferential direction is provided on one end surface side of the tubular portion 18 of the damper body 10. The groove 24, the liquid discharge port 32 that guides the liquid inside the pressure chamber 34 of the first damper 14 to one of the concave grooves 24, and the other of the concave groove 24 are placed in the pressure chamber 40 of the second damper 16. A fluid guide portion 36 provided in the partition wall 12 is provided to guide the liquid supply port 38 to communicate with, and the upper surface of the opening of the concave groove 24 is closed with a member to close the concave groove 24 and the opening thereof. The damper main body is composed of a member, a liquid discharge port 32 of the first damper, the fluid guide portion 36, and a liquid supply port 38 provided in the partition wall 12 and communicating with the pressure chamber 40 of the second damper. A long and narrow flow path extending along the tubular portion 18 is formed in 10, and the flow path is used as the first flow path 66 of the first damper.
Further, in the present invention, the flow path resistance of the second flow path 70 of the second damper 16 is set to be at least twice as large as the flow path resistance of the second flow path 68 of the first damper 14. It is a feature.

In the present invention, ink mainly flows through the first flow path having a small flow path resistance when the liquid is filled, and the liquid flows first from the first flow path having a small flow path resistance when the liquid is discharged. Even after the flow to the first flow path discharge port is interrupted due to the lowering of the liquid water level in the pressure chamber, the liquid can flow from the second flow path having a large flow path resistance, so that the pressure chamber is filled. The liquid can be completely discharged. Therefore, the liquid such as ink filled in the pressure chamber can be easily discharged completely, and the time required for cleaning in the path such as when changing the ink type can be shortened. In addition, the number of times the cleaning liquid is supplied and discharged can be reduced.

It is a front explanatory view of the damper mechanism which omitted the flexible film and the leaf spring. It is the back explanatory view of the damper mechanism which omitted the flexible film and the leaf spring. It is a cross-sectional explanatory view of line AA of a damper mechanism. It is sectional drawing BB of a part of a damper mechanism. It is the back appearance explanatory drawing of the damper mechanism which omitted the flexible film. It is explanatory drawing of this invention.

The configuration of the present invention will be described in detail below with reference to the accompanying drawings.
FIG. 6 is a schematic explanatory view of the inkjet recording apparatus 2, in which the inkjet recording apparatus 2 moves each print head 4 with respect to the recording medium in the main scanning direction with respect to the carriage on which the plurality of inkjet print heads 4 are mounted. Ink is ejected from the nozzle portion 4a (ink ejection portion) of the above to print a dot pattern in a predetermined area, and when the main scanning for the print width is completed, the recording medium is moved by a predetermined amount in the sub-scanning direction, and these operations are performed. By repeating the above steps, all desired areas are printed.
On the other hand, a capping mechanism 76 capable of sealing the nozzle forming surface of the print head 4 is arranged in a non-printing region (home position) on the movement path of the carriage. Further, on the upper surface of the capping mechanism 76, a cap member formed of an elastic material such as rubber that can be tightly sealed on the nozzle forming surface of the print head 4 is arranged. Then, when the carriage moves to the home position, the capping mechanism 76 moves (rises) to the print head 4 side, and the nozzle forming surface of the print head 4 can be sealed by the cap member. There is.

This cap member seals the nozzle forming surface of the print head 4 during the rest period of the inkjet recording device 2 (when waiting for the next printing, when the power of the device is turned off, etc.), and the nozzle opening Functions as a lid to prevent drying. Further, one end of the tube 78 of the suction pump (tube pump) 72 as a suction means is connected to the lower bottom portion of the cap member, and a negative pressure from the suction pump 72 is applied to the print head 4 to cause the print head 4 to perform. It is also designed to perform a cleaning operation that sucks and discharges ink. The ink sucked by the suction pump 72 is collected in the waste liquid recovery box 74.

The carriage on which the inkjet print head 4 is mounted is equipped with a damper mechanism 8 as a liquid storage mechanism that buffers pressure fluctuations generated in ink in an ink supply path 6 including an ink tube. In the damper mechanism 8, the ink in the ink supply path 6 moves due to the inertial force generated by the movement of the carriage, whereby the pressure applied to the ink in the nozzle of the ink ejection portion 4a of the print head 4 is relieved, and the ink is ink. Prevents poor discharge and destruction of the ink in the nozzle opening. Due to the difference between the liquid level of the ink supply unit 7 composed of ink cartridges and the like arranged on the main body side of the inkjet recording device 2 and the ink ejection unit 4a of the print head 4, the ink in the ink supply path 6 and the ink in the print head 4 Is held at a negative pressure, so that the ink does not leak from the nozzle, and when the ink is not ejected, a meniscus is formed in the opening of the nozzle of the ink ejection portion 4a.

In this embodiment, for convenience of explanation, only one damper will be described, and the description of other dampers prepared for each print head will be omitted.
FIG. 1 shows a front explanatory view of the damper, and FIG. 2 shows a rear explanatory view. In order to show the inside of the pressure chamber, the flexible film and the leaf spring are omitted. As shown in FIGS. 1 and 2, in the damper mechanism 8, the first damper 14 and the second damper 16 are formed on both sides of the partition wall 12 of the damper main body 10. The damper main body 10 includes a disk-shaped partition wall 12, a tubular portion 18 formed around the partition wall 12, and connecting portions 19 and 20 protruding from the tubular portion 18. A concave groove 22 extending a predetermined length along the circumferential direction of the opening end and a concave groove 24 are formed on one open end side of the tubular portion 18.

An upstream connecting pipe 26 is attached to the connecting portion 19, and the pipe 26 communicates with a pipeline 28 provided in the connecting portion 19. The pipeline 28 is connected to one side of the groove 22. The upstream connection pipe 26 is connected to a tube constituting the ink supply path 6 of the inkjet recording device 2. The other end of the groove 22 communicates with the pressure chamber 34 of the first damper 14 through the liquid supply port 30 formed in the tubular portion 18. The liquid discharge port 32 is located above the bottom of the bottom surface of the pressure chamber 34 by a predetermined interval, and constitutes the first flow path 66.

As shown in FIG. 4, the other end of the concave groove 24 communicates with a fluid guide portion 36 having a hollow portion, which is integrally formed in the tubular portion 18. As shown in the figure, the liquid supply port 38 formed in the partition wall 12 is slightly expanded in a funnel shape at one portion thereof, the hollow portion of the guide portion 36 communicates with the flow hole 38, and the concave groove 24 is a fluid. Inside the guide portion 36, the liquid supply port 38 communicates with the pressure chamber 40 of the second damper 16. A SUS (stainless steel) mesh filter 42 is adhered to the partition wall 12 at a position facing the liquid supply port 38, and the filter 42 removes minute foreign substances in the ink entering the second damper 16. It is configured in.

A concave groove 44 extending by a predetermined length along the circumferential direction of the opening is formed on the other opening end side of the tubular portion 18. One of the concave grooves 44 is connected to the liquid discharge port 46 formed at a position away from the liquid supply port 38 of the tubular portion 18, and the other of the concave grooves 44 is a conduit provided in the connection portion 20. It is connected to one of 48. The liquid discharge port 46 is arranged so as to be located above the bottom of the bottom surface of the pressure chamber 40 by a predetermined interval. The pipeline 48 constitutes a first flow path 64 for discharging liquid. The other side of the pipeline 48 is connected to a downstream connecting pipe 50 fixed to the connecting portion 20, and the connecting pipe 50 is connected to an ink supply pipe 52 (see FIG. 6) connected to the print head 4. .. The damper body 10 is formed with recesses on both side surfaces by the tubular portion 18, and one end surface is formed by sealing the openings of the recesses with film-shaped flexible films 52 and 54 (see FIG. 3). Pressure chambers 34 and 40 defined by the flexible films 52 and 54 are formed. The flexible films 52 and 54 are sealed with a margin so that they can be sufficiently bent to the outside and the inside.

Ink is filled into the pressure chambers 34 and 40 of the first and second dampers 14 and 16 by sealing the head by the capping mechanism 76 and then sucking ink from the nozzle opening of the ink ejection portion 4a by the pump 72. Will be done.
By this suction, the ink stored in the ink supply unit 7 passes through the ink supply path 6, the flow path 62, the pressure chamber 34 of the first damper of the damper mechanism 8, the first flow path 66 for pressure resistance, and the like. By passing through the liquid supply port 38, the filter 42, the pressure chamber 40 of the second damper, and the first flow path 64, the ink enters the print head 4, and the ink is sucked to the extent that some ink is withdrawn from the ink ejection portion 4a. Fill.

When the suction is completed, the ink in the path is held at a negative pressure due to the difference between the head values of the ink supply unit 7 and the print head 4, and the ink can be ejected from the ink ejection unit 4a. At this stage, the flexible films of the pressure chamber 34 of the first damper and the pressure chamber 40 of the second damper are regulated by the leaf springs 56 and 58 and are maintained in a slightly recessed state and filled with ink. .. After that, as the ink is ejected from the head, the ink is supplied in the direction of the inkjet head 4, so that the ink in the pressure chamber 34 of the first damper and the pressure chamber 40 of the second damper decreases, and the ink is supplied by the decrease. The ink of the part 7 is supplied, and the print head 4 is periodically filled with the required amount of ink.

For example, the flexible films 52 and 54 are formed by the damper main body 10 by sucking the ink in the pressure chambers 34 and 40 of the first and second dampers 14 and 16 by suction by the capping mechanism 76 or ejecting ink from the head. If it sticks to the partition wall 12, the flexible film blocks the ink supply path from the upstream, which may hinder the ink supply. In this case, most of the ink in the pressure chambers 34 and 40 of the first and second dampers 14 and 16 is discharged, which causes the nozzle to come off.

Therefore, by arranging the first and second leaf springs 56 and 58 at positions forming a predetermined clearance, the contact of the flexible membranes 52 and 54 with the partition wall 12 of the damper body 10 is restricted. The leaf springs 56 and 58 are arranged by engaging the refracting portion with the engaging recesses 60 and 61 provided at the opening edge of the tubular portion 18, and the flexible films 52 and 54 are attached to the leaf springs 56 and 58. Even when the position is attached, the pressure chambers 34 and 40 of the first and second dampers 14.16 are filled with a predetermined amount of ink, and further displacement is possible from this portion. The flexible film 52 is also prevented from sticking to the partition wall 12. The flexible films 52 and 54 are joined to the opening edge of the tubular portion 18 by heat welding or the like.

The openings of the concave grooves 22, 24, 44 and the fluid guide portion 36 are sealed by the flexible films 52, 54, and the cylinders are formed by the concave grooves 22, 24, 44, the fluid guide portion 36, and the flexible membranes 52, 54. On both end faces of the portion 18, along the concave grooves 22, 24, 44 and the fluid guide portion 36, a flow path 62 for filling liquid, which is composed of an elongated pipe having a predetermined length, and a first for discharging liquid. The flow path 64 and the first flow path 66 for pressure resistance and liquid discharge are formed. It is the outer portion of the flexible membranes 52 and 54 that is not used as the flexible portion that closes the opening, and a flow path is created by welding that portion to the damper body 10.

In this embodiment, since the flexible film is welded to cover both the pressure chamber and the groove together, it is easy to create, and if a transparent member or the like is used, the state of the ink inside can be grasped. .. When using ink that is affected by light (for example, ultraviolet curable ink), it is necessary to use a light-shielding member.
Next, the second flow paths 68 and 70 for bypass connected to the first flow paths 64 and 66 for discharging the liquid will be described.
The flow path resistance of the second flow paths 68 and 70 is set larger than that of the first flow paths 64 and 66. A narrow groove 80 is formed on one open end side of the tubular portion 14, and one of the concave grooves 80 is at or near the bottom of the pressure chamber 34 of the first damper 14, that is, the lowest position of the pressure chamber 34. The other side of the concave groove 80 is connected to the side portion of the first flow path 66.

The open surface side of the concave groove 80 along the longitudinal direction is sealed by the flexible film 52, and the concave groove 80 and the flexible film 52 form the bottom of the pressure chamber 34 and the side of the first flow path 66. A second flow path 68 for liquid bypass flow is formed. A narrow groove 82 is formed on the other open end side of the tubular portion 14, and one of the concave grooves 82 is the bottom of the pressure chamber 40 of the second damper 16, that is, the lowest position of the pressure chamber 40 or a position thereof. It opens close and the other end of the recess 82 is connected to the side of the first flow path 64. The open surface side of the concave groove 82 along the longitudinal direction is sealed by the flexible film 54, and the concave groove 82 and the flexible film 54 form the bottom of the secondary pressure chamber 40 and the first flow on the secondary side. A second flow path 70 for liquid bypass flow is formed which connects the side portion of the road 64 with a pipeline.

In the present embodiment, the pressure loss of the second flow paths 68 and 70 is set to be 15 times or more the pressure loss caused by the flow path resistance of the cross sections of the first flow paths 64 and 66. When the pressure loss of the second flow paths 68 and 70 is smaller than 15 times, the filling of the pressure chamber for easy flow of ink into the second flow path during ink filling does not proceed and the ink is wasted. It will be. In the present embodiment, in order to efficiently discharge the liquid such as ink in the pressure chamber, the liquid in the pressure chamber 34 on the primary side is discharged first. Therefore, the flow path resistance of the second flow path 70 on the secondary side is set to be at least twice the flow path resistance of the second flow path 68 on the primary side.

In the above configuration, the pressure chambers 34 and 40 of the first and second dampers 14 and 16 are filled with the ink in the ink ejection portion 4a by the pump 72, and the first and second dampers 14 and 16 are filled. Ink is filled up to a portion exceeding the liquid discharge ports 32 and 46 of the pressure chambers 34 and 40.
When the inkjet print head 4 moves in the main scanning direction for printing, pressure changes of positive pressure and negative pressure occur in the ink in the ink ejection portion 4a. At this time, the flexible films 52 and 54 are elastically deformed with the pressure change, that is, by changing the volumes of the first and second dampers 14 and 16, the pressure fluctuation is buffered and the inside of the ink ejection portion 4a. A substantially constant negative pressure can be stably maintained in the ink.

The deformation directions of the flexible films 52 and 54 that change the volumes of the first and second dampers 14 and 16 are flexible when the pressure applied from the inside of the ink tube increases as the inkjet print head 4 moves. The films 52 and 54 move in the direction of increasing the volume (in the direction of swelling), and move in the direction of decreasing the volume (in the direction of denting) when the pressure becomes low.

By deforming the flexible films 52 and 54 in this way, the damper mechanism 8 buffers the pressure fluctuation of the ink in the ink supply path 6 in response to the acceleration, deceleration, and movement direction of the inkjet print head 4. The print quality can be improved by stabilizing the ejection by preventing the ink in the ink ejection unit 4a from being affected by the pressure fluctuation.
Next, an operation of suppressing excessive pressure propagation on the head by accelerating and decelerating the inkjet print head will be described.

It is desirable that the pressure fluctuation applied to the print head is as small as possible. When there is only one damper, the pressure fluctuation ΔP generated on the upstream side of the damper is applied to the pressure chamber of the damper, but is also applied evenly to the print head 4 side communicating in the same manner. After that, the flexible film of the damper is displaced and the pressure fluctuation is buffered, but the displacement of the flexible film of the damper cannot catch up momentarily. Therefore, the pressure difference that could not be buffered is moved to the ink ejection portion 4a side of the print head. The influence of.

On the other hand, in the present embodiment, the pressure fluctuation ΔP is first transmitted to the pressure chamber of the first damper through the pipeline 28. Next, the pressure fluctuation ΔP in the pressure chamber of the first damper is transmitted to the first flow path 66, where the existence of a long thin flow path and a filter causes a pressure loss due to the presence of this structure. Is generated, and the pressure fluctuation ΔP decreases to ΔP'. The pressure fluctuation ΔP'is transmitted to the second damper through the first flow path 66 on the primary side, and is transmitted to the print head 4 through the connecting pipe 50.

The pressure fluctuation ΔP on the upstream side of the damper and the pressure fluctuation ΔP'transmitted to the print head 4 are ΔP'<ΔP, and it becomes a pressure resistance in the case of one damper or between a plurality of dampers. Compared with the case where the flow path 66 is not provided, in the present embodiment, the pressure fluctuation applied to the print head 4 side can be reduced, and the pressure fluctuation applied momentarily can also be suppressed. In order to buffer a large pressure fluctuation, it is necessary to strengthen the flexible film or spring of the damper mechanism, but in that case, the responsiveness is deteriorated, so that the responsiveness of the instantaneous pressure fluctuation is deteriorated.

In the present embodiment, by providing a structure in which two dampers are arranged in series and a pressure is lost between them, it is not necessary to make the two dampers as strong as when a flexible film or a spring is provided independently, so that the instantaneous responsiveness is improved. , The pressure applied until the flexible film of the damper is displaced can be reduced.
In the present embodiment, a flow path that acts as a resistance to pressure is formed in a composite damper body in which two dampers are integrally formed back to back, but the configuration is particularly limited to a configuration in which two dampers are integrally formed. Instead, two or a plurality of dampers may be formed separately, and these may be connected in series by a thin pressure resistance pipe such as a tube or a pipe.
Further, in the embodiment, the same structure is used for the first and second dampers, but they do not have to be the same. For example, the capacity of the pressure chamber can be changed by the first and second dampers, or a flexible film or a leaf spring can be used. The strength may be changed individually, and it may be used as needed.

Next, an operation of discharging a liquid such as ink in the damper will be described when the ink is replaced with a different type of ink or when the recording device is stopped for a long period of time.
First, when the ink ejection portion 4a of the print head 4 is connected to the pump 72 and the ink ejection portion 4a is sucked by the pump 72, the suction force of the pump 72 is applied to the first flow path on the secondary side through the downstream connecting pipe 50. It is transmitted to 64, and the liquid in the pressure chamber 40 on the secondary side is sucked into the first flow path 64 through the liquid discharge port 46. At the same time, the liquid in the primary pressure chamber 34 flows into the secondary pressure chamber 40 through the liquid discharge port 32, the first flow path 66, and the liquid discharge port 38.

When the flexible membranes 52 and 54 are recessed to the limit and the water level in the pressure chambers 34 and 40 becomes lower than the height of the liquid discharge ports 32 and 46, the first flow paths 64 and 66 from the liquid discharge ports 32 and 46 are reached. The flow of liquid is cut off. Since the relationship of the flow path resistance between the first flow path 64, 66 and the second flow path 68, 70 is set as follows, the flow path resistance: the first flow path 64, 66 <second flow Road 68 <second flow path 70
After that, the second flow path 68 first acts, and the liquid such as ink remaining in the pressure chamber 34 flows into the first flow path 66, is discharged from the primary side pressure chamber 34, and enters the secondary side pressure chamber 40. Moving.
Next, the second flow path 70 acts, and the liquid such as ink remaining in the pressure chamber 40 flows into the first flow path 64 and is discharged. As described above, the flow of the liquid from the second flow path 68 to the first flow path 66 causes all the liquid in the primary pressure chamber 34 to be discharged, and the second flow path 70 to the first flow path 64. All the liquid in the secondary pressure chamber 40 is discharged by the flow of the liquid, and the discharged liquid is collected in the waste liquid recovery box 74.
To clean the ink in the ink path after discharging the filled ink, change the cartridge 7 to one filled with the cleaning liquid, and repeat the filling and discharging operations of the cleaning liquid to remove the remaining ink in the ink path. Complete the cleaning. After that, when it is not used for a long period of time, it is stored as it is, but when it is used by changing the type of ink, a new ink cartridge 7 is inserted and the ink is filled.

As is clear from the above description, when the damper is filled with ink, the damper pressure chambers 34 and 40 are filled with ink due to the flow of ink from the supply ports 30 and 38 to the ink path. Since there is no ink connection with the first flow paths 66 and 64 until the ink is accumulated up to the ink (liquid) discharge ports 32 and 46, a very slight ink flow may occur from the second flow paths 68 and 70. However, since the ink flow rate from the supply flow path is overwhelmingly large, the pressure chambers 34 and 40 are immediately filled with ink, and the ink is connected to the first ink flow paths 66 and 64 to complete the ink filling. ..

At the time of ink discharge, the ink water level in the pressure chambers 34 and 40 drops, and the ink flow from the first ink path including the first flow paths 64 and 66 is divided (stopped) near the discharge ports 46 and 32. After that, the ink flow is maintained through the second path including the second flow paths 70 and 68, all the ink in the pressure chambers 40 and 34 is discharged, and the ink remains in the pressure chambers 40 and 34. Never.
The present invention is not particularly limited to the damper mechanism as the fluid storage mechanism, and a liquid storage mechanism such as a self-sealing valve unit may be used.

2 Ink jet recording device 4 Printhead 4a Ink ejection part 6 Ink supply path 7 Ink supply part 8 Damper mechanism 10 Damper body 12 Partition 14 First damper 16 Second damper 18 Cylindrical part 19 Connection part 20 Connection part 22 Concave groove 24 Recessed groove 26 Upstream connection pipe 28 Pipeline 30 Liquid supply port 32 Liquid discharge port 34 Pressure chamber 36 Fluid guide 38 Liquid supply port 40 Pressure chamber 42 Filter 44 Concave groove 46 Liquid discharge port 48 Pipeline 50 Downstream side connection pipe 52 Flexible film 54 Flexible film 56 Leaf spring 58 Leaf spring 60 Engagement recess 61 Engagement recess 62 Flow path 64 First flow path 66 First flow path 68 Second flow path 70 Second flow path 72 Pump 74 Waste liquid recovery box 76 Capping mechanism 78 Tube 80 Concave groove 82 Concave groove

Claims (5)

A pressure chamber provided between the liquid supply unit on the main body side of the apparatus and the inkjet print head to store the liquid to be supplied to the inkjet print head is provided, and the pressure chamber has a liquid supply port and a position higher than the bottom of the pressure chamber. In the liquid storage mechanism in the inkjet recording apparatus provided with the liquid discharge port arranged in, a first flow path for flowing the liquid in the pressure chamber in the direction of the print head is connected to the liquid discharge port, and the bottom of the pressure chamber is connected. One of the second flow paths is connected to the first flow path, the other of the second flow path is connected to the first flow path, and the flow path resistance of the second flow path is changed to the flow path of the first flow path. The pressure chamber is set to be larger than the road resistance so that the pressure chamber constitutes a damper mechanism for absorbing the pressure fluctuation applied to the ink in the inkjet printhead, and the damper mechanism is combined with the first damper having the pressure chamber. , A second damper having a pressure chamber, and each pressure chamber of the first damper and the second damper is composed of a wall surface and a flexible film arranged so as to face the wall surface. The first flow path and the second flow path are provided in the first damper and the second damper, respectively, and the first flow path of the first damper is used as a flow for pressure resistance having a predetermined length. The first flow path of the first damper is connected to the pressure chamber of the second damper, and the second flow path of the first damper is connected to the first flow path of the first damper. A liquid storage mechanism in an inkjet recording apparatus, which is connected to a road and the second flow path of the second damper is connected to the first flow path of the second damper. The inkjet recording apparatus according to claim 1, wherein the flow path resistance of the second flow path of the second damper is made larger than the flow path resistance of the second flow path of the first damper. Liquid storage mechanism. A damper body having a partition wall and a cylinder portion forming recesses on both sides of the partition wall is mounted on a carriage on which the inkjet print head is mounted and moves in the main scanning direction across the printing medium, and the cylinder portion is axially oriented. A flexible film is adhered to both end surfaces of the above, pressure chambers are provided on both sides of the partition wall to form a first damper and a second damper, and the first damper is used to drain liquid that communicates with the pressure chamber of the damper. An outlet is provided, a liquid supply port communicating with the pressure chamber of the damper is provided in the second damper, and an upstream connection pipe connected to an ink supply unit on the inkjet recording device main body side and ink discharge of a print head are provided in the damper main body. A downstream connection pipe connected to the portion is provided, a liquid supply port communicating with the pressure chamber of the damper is provided in the first damper, and a liquid discharge port communicating with the pressure chamber of the damper is provided in the second damper. The liquid supply port of the first damper and the upstream connection pipe are connected via a flow path provided in the first damper, and the liquid discharge port of the second damper and the downstream connection pipe are connected. Is connected via the first flow path provided in the second damper, and the liquid discharge port of the first damper and the liquid supply port of the second damper are provided in the first damper. The second flow path of the first damper is connected to the first flow path of the first damper, and the second flow path of the second damper is connected by the first flow path. The liquid storage mechanism in the inkjet recording apparatus according to claim 1, wherein the liquid storage mechanism is connected to the first flow path of the second damper. The partition wall is provided with a liquid supply port communicating with the pressure chamber of the second damper, and a concave groove extending in the circumferential direction is provided on one end surface side of the tubular portion of the damper body, and the pressure chamber of the first damper. A fluid provided in the partition wall, which guides the liquid discharge port of the first damper that guides the internal liquid to one of the concave grooves and the other of the concave grooves to the liquid supply port that communicates with the pressure chamber of the second damper. A guide portion is provided, the upper surface of the opening of the concave groove is closed with a member, the concave groove, a member for closing the opening thereof, a liquid discharge port of the first damper, the fluid guide portion, and the like. A liquid supply port communicating with the pressure chamber of the second damper provided in the partition wall forms an elongated flow path extending along the cylinder portion in the damper main body, and the flow path is used as the first damper. The liquid storage mechanism in the inkjet recording apparatus according to claim 3, further comprising the first flow path of the above. The second aspect of the present invention, wherein the flow path resistance of the second flow path of the second damper is set to be at least twice as large as the flow path resistance of the second flow path of the first damper. A liquid storage mechanism in an inkjet recording device.

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