JP6442953B2 - Liquid ejector - Google Patents

Description

  The present invention relates to a liquid ejecting apparatus.

  2. Description of the Related Art Conventionally, an ink jet recording apparatus is known as one of liquid ejecting apparatuses that eject liquid from a nozzle to a target. The ink jet recording apparatus includes a recording head for ejecting ink, and ejects ink from nozzles formed on the recording head while performing relative movement between the recording head and the recording medium to perform printing on the recording medium. (For example, refer to Patent Document 1).

  Patent Document 1 discloses so-called choke cleaning in which ink is sucked from a recording head through a cap member in order to discharge bubbles, sediment components, and the like that have accumulated in the ink supply path from the ink cartridge to the recording head. In order to do so, an ink jet recording device with a choke valve is described. The choke valve is provided in the ink supply path and opens and closes the ink supply path between the ink cartridge and the recording head.

  In the choke cleaning, first, the choke valve is closed, the nozzle of the recording head is covered with a cap member, and the inside of the ink passage on the downstream side of the choke valve is reduced by reducing the pressure inside the cap member with a suction device. Then, the negative pressure is set, the choke valve is opened, the ink is vigorously poured into the negative pressure ink flow path, and the remaining bubbles and sediment components are discharged from the nozzle at once.

Japanese Patent No. 4396358

  By the way, in the configuration of the prior art, an actuator for opening and closing the choke valve is separately required for cleaning, and there is a problem that the structure is complicated and the manufacturing cost is increased.

  The present invention has been made in view of the above problems, and an object thereof is to provide a liquid ejecting apparatus that can simplify the structure and reduce the manufacturing cost.

In order to solve the above-described problems, the present invention connects a liquid ejecting head that ejects liquid supplied from a liquid container that stores liquid from a nozzle, and the liquid container and the liquid ejecting head. A liquid supply path; a liquid chamber forming a part of the liquid supply path; and an air chamber separated from the liquid chamber via a flexible member, the pressure difference between the liquid chamber and the air chamber The choke valve that opens and closes the liquid supply path by deforming the flexible member, a cap member that covers the nozzle, a suction device that sucks liquid through the cap member, the cap member, and the suction device A liquid discharge path that communicates with the air passage, an air flow path that communicates the liquid discharge path with the air chamber of the choke valve, an opening and closing device that opens and closes the air flow path, and a second that opens and closes the liquid discharge path. Switchgear and front A buffer tank connected to a downstream side of the second opening / closing device in the liquid discharge path and having a predetermined space volume, and the air flow path passes through the buffer tank and the liquid discharge path And a liquid ejecting apparatus that communicates with the air chamber of the choke valve.
In the present invention, a liquid ejecting head that ejects liquid supplied from a liquid container that contains liquid from a nozzle, a liquid supply path that connects the liquid container and the liquid ejecting head, A liquid chamber that forms part of the liquid supply path; and an air chamber that is separated from the liquid chamber via a flexible member, the flexible member depending on a pressure difference between the liquid chamber and the air chamber. A choke valve that opens and closes the liquid supply path, a cap member that covers the nozzle, a suction device that sucks liquid through the cap member, and a connection between the cap member and the suction device A liquid ejecting apparatus having a liquid discharge path, an air flow path connecting the liquid discharge path and the air chamber of the choke valve, and an opening / closing device for opening and closing the air flow path is employed.
By adopting such a configuration, in the present invention, an air flow path is provided and provided in a liquid discharge path that connects the cap member and the suction device, and a liquid supply path that connects the liquid container and the liquid ejecting head. The air chamber of the choke valve is connected, and an opening / closing device is provided in the air flow path so that the liquid discharge path and the air chamber of the choke valve are communicated with each other. When the opening / closing device is closed and the suction device is driven, the ink supply path becomes negative pressure through the liquid discharge path, and the negative pressure is higher in the liquid chamber of the choke valve than in the air chamber, and the choke valve is closed. it can. When the opening / closing device is opened and the suction device is driven, the ink supply path becomes negative pressure via the liquid discharge path, and the air chamber of the choke valve also becomes negative pressure via the air flow path. Here, in the liquid chamber of the choke valve, a negative pressure is applied by reducing the pressure loss in the ink supply path, so the negative pressure in the air chamber of the choke valve is higher than that in the liquid chamber, and the choke valve is opened. Can do. Thus, the choke valve can be opened and closed without providing a separate actuator by combining the air flow path and the opening / closing device and using the suction device for sucking the liquid as the power source. For this reason, in this invention, a structure can be simplified and manufacturing cost can be reduced.

Further, in the present invention, a plurality of the liquid supply paths are provided, the choke valve is provided in each of the plurality of liquid supply paths, and the air flow path is located downstream of the opening / closing device. A configuration is adopted in which it is branched and connected to each of the air chambers of the plurality of choke valves.
By adopting such a configuration, in the present invention, when a plurality of liquid supply paths and choke valves are provided, the air flow path is branched downstream of the opening / closing device, and the air chambers of the plurality of choke valves are separated. By connecting to each, the air chambers of a plurality of choke valves can be made negative pressure. As described above, since the choke valves of all the liquid supply paths can be easily opened and closed only by branching the air flow path, the structure can be simplified and the manufacturing cost can be reduced.

In the present invention, a second opening / closing device that opens and closes the liquid discharge passage, and a part of the liquid discharge passage is formed downstream of the second opening / closing device, and a space volume of the cap member is formed. And a buffer tank having a larger spatial volume, and the air flow path is connected to the buffer tank.
By adopting such a configuration, in the present invention, a second opening / closing device is provided in the liquid discharge path, a buffer tank is provided downstream of the second opening / closing device, the second opening / closing device is closed, and suction is performed. By driving the device, negative pressure can be stored in the buffer tank. Since the buffer tank has a space volume larger than the space volume of the cap member, the inside of the cap member can be made negative pressure all at once by opening the second opening / closing device when necessary, and the cleaning time Can be shortened.

Moreover, in this invention, the structure that the said air flow path is connected to the upper part of the said buffer tank is employ | adopted.
By adopting such a configuration, in the present invention, the air flow path is connected to the upper portion of the buffer tank, thereby preventing the liquid that has flowed into the buffer tank through the cap member from entering the air flow path. be able to.

In the present invention, a pressurizing device for pressurizing air, a second air flow path connecting the pressurizing device and the air chamber of the choke valve, and opening and closing the second air flow path And a third opening / closing device.
By adopting such a configuration, in the present invention, the second air flow path is provided, the pressurizing device and the air chamber of the choke valve are connected, and the third air opening and closing are connected to the second air flow path. A device is provided to allow communication between the pressurizing device and the air chamber of the choke valve. By opening the third opening / closing device and driving the pressurizing device, the air chamber of the choke valve is pressurized via the second air flow path, and the flexible member is deformed by the pressure difference with the liquid chamber, The choke valve can be closed. In this way, the choke valve can be closed by the pressure applied by the pressurizing device, so that the liquid supply path can be reliably closed.

In the present invention, the liquid container includes a pressurizing chamber that pushes out the stored liquid to the liquid supply path, and is upstream of the pressurizing chamber of the liquid container and the third opening / closing device. A configuration is adopted in which a third air flow path that connects the second air flow path on the side is provided.
By adopting such a configuration, in the present invention, the third air flow path is provided, and the pressurizing chamber of the liquid container is connected to the second air flow path upstream of the third opening / closing device. To do. When the third opening / closing device is opened, the air in the pressurizing chamber of the liquid container pressurizes the air chamber of the choke valve via the second and third air flow paths, and is flexible due to the pressure difference from the liquid chamber. The choke valve can be closed by deforming the sex member. Thus, since the choke valve can be closed by the pressure in the pressurizing chamber of the liquid container, the responsiveness of the blockage in the liquid supply path can be enhanced. Further, since the pressurizing chamber of the liquid container is usually much larger in volume than the air chamber of the choke valve, the pressure drop in the pressurizing chamber of the liquid container is very small. For this reason, after opening the third opening / closing device, it is possible to shift to normal printing or cleaning without performing additional pressure.

In the present invention, the suction device is driven in a state where the opening and closing device is closed, the third opening and closing device is opened, and the choke valve is closed by the pressure of the pressurizing chamber of the liquid container. A first cleaning that sucks liquid through a cap member; and the opening / closing device is opened and the third opening / closing device is closed, the suction device is driven, and the liquid supply path, the air flow path, A configuration is adopted in which the second cleaning for sucking the liquid through the cap member while opening the choke valve can be selected by the pressure difference based on the flow path resistance difference.
By adopting such a configuration, in the present invention, the switchgear is closed, the air flow path is disconnected, the third switchgear is opened, and the liquid container is passed through the second and third airflow paths. The first cleaning is performed by exchanging only the liquid in the liquid supply path on the downstream side of the choke valve by driving the suction device in a state where the pressurization chamber and the air chamber of the choke valve are in communication with each other and the choke valve is closed. It can be performed. In the present invention, the third opening / closing device is closed, the second and third air flow paths are disconnected, the opening / closing device is opened, and the liquid discharge path and the air chamber of the choke valve are connected via the air flow path. By driving the suction device in the connected state, the choke valve is opened by the pressure difference based on the flow path resistance difference between the liquid supply path and the air flow path, and the liquid in the liquid supply path upstream of the choke valve The second cleaning can be carried out by replacing up to. As described above, in the present invention, since the first cleaning and the second cleaning can be selected, the two types of cleaning are selectively used as necessary, and the ejection characteristics of the liquid ejection head are suppressed while preventing wasteful consumption of liquid. Can be recovered.

In the present invention, a second liquid chamber provided on the downstream side of the choke valve and forming a part of the liquid supply path, and the second liquid chamber and the second flexible member A second air chamber that is separated by a pressure difference between the second liquid chamber and the second air chamber, and the second flexible member is deformed by a pressure difference between the second liquid chamber and the second air chamber. A liquid reservoir for changing the space volume of the liquid, a fourth air passage connecting the second air chamber of the liquid reservoir and the pressurizer, and opening and closing the fourth air passage. And a fourth switchgear.
By adopting such a configuration, in the present invention, when the liquid reservoir is provided on the downstream side of the choke valve, the fourth air flow path is provided, and the second unit of the pressurizer and the liquid reservoir is provided. While connecting with an air chamber, a 4th opening-and-closing apparatus is provided in this 4th air flow path, and a pressurization apparatus and the 2nd air chamber of a liquid storage part are connected, It is made not to communicate. By opening the fourth opening / closing device and driving the pressurizing device, the second air chamber of the liquid reservoir is pressurized via the fourth air flow path, and the pressure difference with the second liquid chamber causes the first It is possible to deform the flexible member 2 to reduce the space volume and pressurize the liquid supply path. In this way, when necessary, cleaning by pressurization can be performed by pressurizing the second air chamber of the liquid reservoir.

In the present invention, a configuration is adopted in which a self-sealing valve is provided on the upstream side of the choke valve and opens the liquid supply path by the difference between the pressure of the liquid supply path and atmospheric pressure.
By adopting such a configuration, in the present invention, a self-sealing valve that opens when the pressure of the liquid supply path is lower than atmospheric pressure and replenishes liquid as needed is provided upstream of the choke valve. Therefore, an appropriate negative pressure can be generated for the liquid jet head during cleaning.

1 is a plan view showing a printer in an embodiment of the present invention. FIG. 2 is a schematic diagram illustrating an ink supply system and an ink discharge system of the printer according to the embodiment of the present invention. It is a figure for demonstrating the 1st cleaning of the printer in embodiment of this invention. It is a figure for demonstrating the 2nd cleaning of the printer in embodiment of this invention.

  Hereinafter, embodiments of a liquid ejecting apparatus according to the invention will be described with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size. In this embodiment, an ink jet printer (hereinafter referred to as a printer) is exemplified as the liquid ejecting apparatus according to the invention.

FIG. 1 is a plan view showing a printer PRT according to an embodiment of the present invention.
The printer PRT shown in FIG. 1 is a device that performs a printing process while conveying a sheet-like recording medium M such as paper or a plastic sheet. The printer PRT includes a housing PB, an inkjet mechanism IJ that ejects ink onto the recording medium M, an ink supply mechanism IS that supplies ink to the inkjet mechanism IJ, a transport mechanism CV that transports the recording medium M, and an inkjet mechanism. A maintenance mechanism MN that performs IJ maintenance operations and a control device CONT that controls these mechanisms are provided.

  Hereinafter, an XYZ rectangular coordinate system is set, and the positional relationship of each component will be described with reference to the XYZ rectangular coordinate system as appropriate. In this embodiment, the conveyance direction of the recording medium M is the X-axis direction, the direction orthogonal to the X-axis direction on the conveyance surface of the recording medium M is the Y-axis direction, and the direction perpendicular to the plane including the X-axis and the Y-axis Is expressed as the Z-axis direction.

  The housing PB is formed so that the Y-axis direction is the longitudinal direction. Each part of the inkjet mechanism IJ, the ink supply mechanism IS, the transport mechanism CV, the maintenance mechanism MN, and the control device CONT is attached to the housing PB. A platen 13 is provided in the housing PB. The platen 13 is a support member that supports the recording medium M. The platen 13 is disposed in the central portion of the housing PB in the X-axis direction. The platen 13 has a flat surface 13a directed to the + Z side. The flat surface 13a is used as a support surface that supports the recording medium M.

  The transport mechanism CV includes a transport roller, a motor that drives the transport roller, and the like (both not shown). The transport mechanism CV transports the recording medium M from the −X side of the housing PB into the housing PB and discharges the recording medium M from the + X side of the housing PB to the outside of the housing PB. The transport mechanism CV transports the recording medium M so that the recording medium M passes over the platen 13 inside the housing PB. In the transport mechanism CV, the transport timing, transport amount, and the like are controlled by the control device CONT.

  The inkjet mechanism IJ includes an inkjet head H that ejects ink (liquid), and a head moving mechanism AC that holds and moves the inkjet head H (liquid ejection head). The ink jet head H ejects ink toward the recording medium M sent out on the platen 13. The inkjet head H has an ejection surface Ha on which nozzles that eject ink are formed. The ejection surface Ha is directed in the Z-axis direction and is disposed so as to face the support surface of the platen 13.

  The head moving mechanism AC has a carriage CA. The inkjet head H is fixed to the carriage CA. The carriage CA is configured to be movable along a guide shaft 8 installed in the longitudinal direction (Y-axis direction) of the housing PB. The inkjet head H and the carriage CA are disposed on the + Z side with respect to the platen 13.

  The head moving mechanism AC includes a carriage CA, a pulse motor 9, a drive pulley 10 that is rotationally driven by the pulse motor 9, and a side (+ Y side) on which the drive pulley 10 is provided in the longitudinal direction of the housing PB. A driven pulley 11 provided on the opposite side (−Y side) and a timing belt 12 spanned between the driving pulley 10 and the driven pulley 11 are provided.

  The carriage CA is connected to the timing belt 12. The carriage CA is provided to be movable in the Y-axis direction as the timing belt 12 rotates. When moving in the Y-axis direction, the carriage CA is guided by the guide shaft 8.

  The maintenance mechanism MN is disposed at the home position of the inkjet head H. This home position is set in an area outside the area where printing is performed on the recording medium M. In the present embodiment, the home position is set on the + Y side of the platen 13. The home position is a place where the inkjet head H stands by when the printer PRT is turned off or when recording is not performed for a long time.

  The maintenance mechanism MN includes a cap member CP that covers the nozzles of the inkjet head H, a wiping member WP that wipes the ejection surface Ha, and the like. A suction device SC such as a suction pump is connected to the cap member CP. The cap member CP can suck ink from the inkjet head H by the suction device SC.

  The ink supply mechanism IS supplies ink to the inkjet head H. The ink supply mechanism IS has a plurality of ink cartridges CTR (liquid container). The printer PRT of the present embodiment employs a configuration (off-carriage type) in which the ink cartridge CTR is not mounted on the carriage CA, unlike the inkjet head H.

FIG. 2 is a schematic diagram illustrating an ink supply system and an ink discharge system of the printer PRT according to the embodiment of the present invention.
The ink supply mechanism IS has an ink supply path 20 that connects between the ink cartridge CTR and the inkjet head H. In the ink supply path 20, a self-sealing valve 30, a choke valve 40, a head tank 50 (liquid storage part) are provided downstream of a check valve 20 a (check valve) that prevents backflow of ink to the ink cartridge CTR side. Is provided. The ink supply path 20 is provided in each of the plurality of ink cartridges CTR (see FIG. 1).

  The self-sealing valve 30 opens the ink supply path 20 by the difference between the pressure of the ink supply path 20 and the atmospheric pressure. That is, the self-sealing valve 30 is configured to open the ink supply path 20 and replenish ink from the upstream side when ink is consumed from the inkjet head H and the downstream side becomes negative pressure. Since the configuration of the self-sealing valve 30 is known, a detailed description thereof will be omitted, but a valve body (not shown) that opens and closes the ink supply path 20 and a biasing member that biases the valve body in the closing direction (not shown). And a flexible member (not shown) that pushes the valve body against the urging of the urging member when the ink supply path 20 becomes a negative pressure due to atmospheric pressure.

  The choke valve 40 is provided on the downstream side of the self-sealing valve 30. The choke valve 40 includes an ink chamber 41 (liquid chamber) that forms a part of the ink supply path 20, and an air chamber 42 that is separated from the ink chamber 41 by a flexible member 43. The flexible member 43 is deformed by the pressure difference with the air chamber 42 to open and close the ink supply path 20. The operating pressure of the choke valve 40 can be adjusted by an operating pressure adjusting spring 44.

  The ink chamber 41 is formed inside the casing of the choke valve 40, and a part of the wall surface is formed by the flexible member 43. The inlet of the ink chamber 41 is formed on the bottom surface 41a, and the outlet of the ink chamber 41 is formed above the bottom surface 41a. For this reason, when the flexible member 43 is recessed, the outlet of the ink chamber 41 is closed. Thereby, the choke valve 40 can block the ink supply path 20. In the ink chamber 41 of the present embodiment, for example, 130 ml (milliliter) of ink can be stored.

  The air chamber 42 is a space on the opposite side to the ink chamber 41 (ink supply path 20) through the flexible member 43 in the internal space of the casing of the choke valve 40. That is, the air chamber 42 is partly formed by the flexible member 43. The air chamber 42 of the present embodiment is configured to have a space volume of 15 ml, for example, when 130 ml of ink is stored in the ink chamber 41.

The flexible member 43 is formed from, for example, a single-layer or multi-layer flexible resin film (for example, an elastomer). The flexible member 43 is fixed to the inner wall surface of the choke valve 40 with a predetermined slack so as to cover the inlet and outlet of the ink chamber 41.
The operating pressure adjusting spring 44 adjusts the operating pressure of the choke valve 40 and is arranged in the ink chamber 41 and configured to urge the flexible member 43 toward the air chamber 42. The working pressure adjustment spring 44 of the present embodiment is a spring so that, for example, when the ink chamber 41 becomes −4 kPa (kilopascal) with respect to the air chamber 42, the flexible member 43 is deformed toward the ink chamber 41. Is set.

  A head tank 50 is provided on the downstream side of the choke valve 40 configured as described above. The head tank 50 is separated by an ink chamber 51 (second liquid chamber) that forms a part of the ink supply path 20, and the ink chamber 51 and the flexible member 53 (second flexible member). The air chamber 52 (second air chamber) is provided, and the flexible member 53 is deformed by the pressure difference between the ink chamber 51 and the air chamber 52 to change the space volume of the ink chamber 51. The operating pressure of the head tank 50 can be adjusted by an operating pressure adjusting spring 54.

  The ink chamber 51 is formed inside the head tank 50, and a part of the wall surface is formed by the flexible member 53. The inlet and outlet of the ink chamber 51 are formed below the bottom surface 51a. For this reason, even if the flexible member 53 is recessed, the ink supply path 20 in the head tank 50 is not blocked. In the ink chamber 51 of the present embodiment, for example, 255 ml of ink can be stored.

  The air chamber 52 is a space on the opposite side to the ink chamber 51 (ink supply path 20) through the flexible member 53 in the internal space of the head tank 50. That is, the air chamber 52 is partly formed by the flexible member 53. The air chamber 52 of the present embodiment is configured to have a space volume of 50 ml, for example, when 255 ml of ink is stored in the ink chamber 51.

The flexible member 53 is formed from, for example, a single-layer or multi-layer flexible resin film (for example, an elastomer). The flexible member 53 is fixed to the inner wall surface of the head tank 50 with a predetermined slack so as to cover the inlet and outlet of the ink chamber 51.
The operating pressure adjusting spring 54 adjusts the operating pressure of the head tank 50, and is arranged in the ink chamber 51 to bias the flexible member 53 toward the air chamber 52. The working pressure adjustment spring 54 of the present embodiment is a spring so that, for example, when the ink chamber 51 becomes −4 kPa (kilopascal) with respect to the air chamber 52, the flexible member 53 is deformed toward the ink chamber 51. Is set.

  On the other hand, the maintenance mechanism MN has an ink discharge path 60 that connects between the cap member CP and the suction device SC. In the ink discharge path 60, a valve 60 a (second opening / closing device) and a buffer tank 61 are provided on the upstream side of the check valve 60 b that prevents backflow of ink to the cap member CP side. A valve 60c that is opened when the suction device SC is driven is provided on the downstream side of the suction device SC.

  The valve 60a opens and closes the ink discharge path 60 and is provided on the downstream side of the cap member CP. The valve 60a is provided on the ink discharge path 60 closer to the cap member CP than the suction device SC. The valve 60 a of the present embodiment is configured to open and close the ink discharge path 60 between the cap member CP and the buffer tank 61.

  The buffer tank 61 forms a part of the ink discharge path 60 on the downstream side of the valve 60a and has a space volume larger than the space volume of the cap member CP. The buffer tank 61 of the present embodiment has a space volume of 250 ml, which is approximately three times that of the cap member CP, for example, if the space volume of the cap member CP is 75 ml. An air flow path 62 is connected to the upper part 61 a of the buffer tank 61. The air flow path 62 is provided with a valve 62a that is opened when the air is released to the atmosphere. The outlet of the buffer tank 61 is formed in the lower part 61 b, and ink is discharged from the lower part 61 b of the buffer tank 61 when the suction device SC is driven.

  An air flow path 70 connects between the ink discharge path 60 and the air chamber 42 of the choke valve 40. The air flow path 70 is for operating some elements (such as the choke valve 40) of the ink supply system of the ink supply mechanism IS by the ink discharge system of the maintenance mechanism MN. One end of the air flow path 70 is connected to the upper part 61 a of the buffer tank 61. The other end of the air flow path 70 is connected to the air chamber 42 of the choke valve 40. The upstream side of the air flow path 70 is the buffer tank 61 side, and the downstream side is the air chamber 42 side of the choke valve 40.

  The air flow path 70 is provided with a valve 70a (opening / closing device). The valve 70a opens and closes the air flow path 70. The valve 70 a is provided in the air flow path 70 closer to the ink discharge path 60 than the air chamber 42 of the choke valve 40. The valve 70 a of the present embodiment is configured to open and close the air flow path 70 between the buffer tank 61 and the air chamber 42 of the choke valve 40.

  Further, pressurized air from a pressurizing device 80 is supplied to the air chamber 42 of the choke valve 40. The pressurizing device 80 and the air chamber 42 of the choke valve 40 are connected by an air flow path 81 (second air flow path). The air flow path 81 of the present embodiment merges with the air flow path 70, but may be connected in parallel to the air chamber 42 of the choke valve 40 without merging. The upstream side of the air flow path 81 is the pressurizing device 80 side, and the downstream side is the air chamber 42 side of the choke valve 40.

The air flow path 81 is provided with a valve 81a (third opening / closing device). The valve 81a opens and closes the air flow path 81. The valve 81 a is provided in the air flow path 81 on the upstream side (side closer to the pressurizing device 80) than the joining position with the air flow path 70.
An air flow path 82 for taking in air is connected to the pressurizing device 80. The air flow path 82 is provided with a valve 82a that is opened when the pressurizing device 80 is driven. Instead of the valve 82a, a check valve or the like that prevents backflow may be used.

  The pressurizing device 80 includes a pressurizing pump that pressurizes the pressurizing chamber 84 that houses the ink pack 83 of the ink cartridge CTR. An air channel 85 is connected between the pressurizing chamber 84 of the ink cartridge CTR and the air channel 81 on the upstream side of the valve 81a. The upstream side of the air flow path 85 is the pressurizing device 80 side, and the downstream side is the pressurizing chamber 84 side of the ink cartridge CTR. When the pressure device 80 is driven in a state where the valve 81 a is closed, the pressure chamber 84 can be pressurized via the air flow path 85.

  The pressurizing device 80 of the present embodiment pressurizes the pressurizing chamber 84 of the ink cartridge CTR at 35 ± 3 kPa, for example. In addition, the space volume of the pressurizing chamber 84 according to the present embodiment includes, for example, a space volume of 1700 ml when the ink pack 83 is full, and when the ink pack 83 is empty, It has a space volume of 4075 ml. As described above, the pressurizing chamber 84 of the present embodiment has a space volume that is 100 times or more the air chamber 42 (15 ml) of the choke valve 40 even when the ink pack 83 is full. The space volume is 30 times or more that of the air chamber 52 (50 ml).

  The air chamber 52 of the head tank 50 and the pressurizing device 80 are connected by an air channel 86 (fourth air channel). The air flow path 86 of the present embodiment joins the air flow paths 70 and 81 and is connected to the pressurizing apparatus 80, but may be directly connected to the pressurizing apparatus 80 without joining. The upstream side of the air flow path 86 is the pressurizing device 80 side, and the downstream side is the air chamber 52 side of the head tank 50. The air flow path 86 is provided with a valve 86a (fourth opening / closing device). The valve 86a opens and closes the air flow path 86. The valve 86 a is provided in the air flow path 86 on the downstream side (side closer to the air chamber 52) than the joining position with the air flow path 70.

  In the printer PRT having the above-described configuration, the first cleaning that performs suction by the suction device SC in a state where the ink supply path 20 is pressurized by the pressure device 80 via the ink cartridge CTR, and the ink supply path 20 by the pressure device 80. The second cleaning in which suction is performed by the suction device SC in a state where no pressure is applied is selectable. As the first cleaning, there is wiping cleaning that restores the ejection characteristics of the inkjet head H by replacing a small amount of ink. Further, as the second cleaning, there are normal cleaning in which the ink is replaced while the choke valve 40 is opened, and choke cleaning in which the ink is replaced by opening and closing the choke valve 40.

First, the first cleaning (wiping cleaning) will be described with reference to FIG.
In the wiping cleaning, the valve 70a is closed and the air flow path 70 is disconnected. Further, the valve 86a is closed, and the air flow path 86 is not communicated. Next, the valve 81a is opened, and the air flow path 81 is communicated. During operation, the pressurizing chamber 84 of the ink cartridge CTR is pressurized by the pressurizing device 80. Therefore, when the valve 81a is opened, the air in the pressurizing chamber 84 of the ink cartridge CTR flows backward, and the air flow path 85, The air chamber 42 of the choke valve 40 is pressurized via 81. When the air chamber 42 of the choke valve 40 is pressurized, the flexible member 43 is deformed to the bottom surface 41a side due to the pressure difference with the ink chamber 41, and the choke valve 40 is closed as shown in FIG.

  Next, the valve 86a is opened, and the air flow path 86 is communicated. When the valve 86 a is opened, the air in the pressurizing chamber 84 of the ink cartridge CTR flows backward, and the air chamber 52 of the head tank 50 is pressurized via the air flow paths 85, 81, 70, 86. When the air chamber 52 of the head tank 50 is pressurized, the flexible member 53 is deformed to the bottom surface 51a side due to the pressure difference with the ink chamber 51, and as shown in FIG. Shrink. When the ink chamber 51 contracts, the upstream side of the ink supply path 20 is closed by the choke valve 40, so that the ink stored in the ink chamber 51 is ejected from the nozzles of the inkjet head H on the downstream side of the ink supply path 20. Is pushed out.

The ink ejected from the nozzles of the inkjet head H wets the ejection surface Ha. Further, the excess ink dropped from the ejection surface Ha is received by the cap member CP and is collected through the ink discharge path 60 by driving the suction device SC. When the excess ink is collected, the maintenance mechanism MN removes the cap member CP from the inkjet head H, and wipes the ejection surface Ha with the wiping member WP (see FIG. 1). Since the ejection surface Ha is wet with ink, the removal rate of foreign matters (thickened ink, dust, etc.) by the wiping member WP can be improved.
Therefore, according to this wiping cleaning, the success rate of cleaning is increased, and ink consumption can be suppressed to about the capacity of the head tank 50.

  As described above, in the present embodiment, the air flow path 81 is provided, the pressurizing device 80 is connected to the air chamber 42 of the choke valve 40, and the air flow path 81 is provided with the valve 81 a. And the air chamber 42 of the choke valve 40 are communicated with each other. By opening the valve 81 a and driving the pressurizing device 80, the air chamber 42 of the choke valve 40 is pressurized via the air flow path 81, and the flexible member 43 is deformed by the pressure difference with the ink chamber 41. The choke valve 40 can be closed. In this way, the choke valve 40 can be closed by the pressure applied by the pressurizing device 80, so that the ink supply path 20 can be reliably closed.

  In the present embodiment, an air flow path 85 is provided to connect the pressurizing chamber 84 of the ink cartridge CTR and the air flow path 81 upstream of the valve 81a. When the valve 81 a is opened, the air in the pressurizing chamber 84 of the ink cartridge CTR pressurizes the air chamber 42 of the choke valve 40 through the air flow paths 85 and 81, and the flexible member is caused by the pressure difference with the ink chamber 41. 43 can be deformed and the choke valve 40 can be closed. Thus, the choke valve 40 can be closed by the pressure in the pressurizing chamber 84 of the ink cartridge CTR, so that the responsiveness of the blockage in the ink supply path 20 can be enhanced. In addition, since the pressurizing chamber 84 of the ink cartridge CTR usually has a much larger space volume than the air chamber 42 of the choke valve 40, the pressure drop in the pressurizing chamber 84 of the ink cartridge CTR is very small. For this reason, after the valve 81a is opened, it is possible to shift to normal printing or cleaning without performing additional pressure.

  In the present embodiment, when the head tank 50 is provided on the downstream side of the choke valve 40, the air flow path 86 is provided to connect between the pressurizing device 80 and the air chamber 52 of the head tank 50. The air flow path 86 is provided with a valve 86a to allow the pressurizing device 80 and the air chamber 52 of the head tank 50 to communicate with each other. By opening the valve 86a and driving the pressurizing device 80, the air chamber 52 of the head tank 50 is pressurized via the air flow path 86, and the flexible member 53 is deformed by the pressure difference with the ink chamber 51, The space volume can be reduced and the ink supply path 20 can be pressurized. In this way, when necessary, cleaning by pressurization can be performed by pressurizing the air chamber 52 of the head tank 50. In the present embodiment, since the air flow path 86 is connected to the pressurizing chamber 84 of the ink cartridge CTR, the responsiveness can be improved by using the pressure of the pressurizing chamber 84 of the ink cartridge CTR.

  Next, the second cleaning (normal cleaning) will be described with reference to FIG.

  In normal cleaning, the valve 81a is closed and the air flow path 81 is not communicated. Next, the valve 70a is opened, and the air flow path 70 is communicated. Further, the valve 60a is opened to allow the ink discharge path 60 to communicate. When the suction device SC is driven in this state, the ink discharge path 60 becomes negative pressure, ink is sucked out from the nozzles of the inkjet head H via the cap member CP, and the ink supply path 20 becomes negative pressure. Further, when the ink discharge path 60 becomes negative pressure, the air flow path 70 connected to the buffer tank 61 also becomes negative pressure.

Here, when the pressure loss between the ink supply path 20 and the air flow path 70 is compared, the pressure loss in the ink supply path 20 is larger than that in the air flow path 70 due to differences in the viscosity of the flowing medium and the flow path area. Become. Then, the negative pressure is higher in the air chamber 42 of the choke valve 40 to which the air flow path 70 is connected than in the ink chamber 41 of the choke valve 40 that is a part of the ink supply path 20. When the negative pressure of the air chamber 42 of the choke valve 40 is increased, the flexible member 43 is deformed (swelled) on the side opposite to the bottom surface 41a due to the pressure difference with the ink chamber 41, and as shown by the solid line in FIG. The valve 40 is kept open. If the valve 86a is opened together with the valve 70a, the head tank 50 can be expanded as in the choke valve 40.
Therefore, according to this normal cleaning, it is possible to perform the cleaning while avoiding unnecessary blockage of the ink supply path 20 when the chalk cleaning (described later) is not performed.

  Next, the second cleaning (choke cleaning) will be described with reference to FIG.

  In the choke cleaning, the valve 70a is closed and the air flow path 70 is disconnected. Further, the valve 81a is closed, and the air flow path 81 is not communicated. Next, the valve 60a is opened to allow the ink discharge path 60 to communicate. When the suction device SC is driven in this state, the ink discharge path 60 becomes negative pressure, ink is sucked out from the nozzles of the inkjet head H via the cap member CP, and the ink supply path 20 becomes negative pressure. On the other hand, the air flow path 70 does not become negative pressure because the valve 70a is closed.

  As a result, the negative pressure is higher in the ink chamber 41 of the choke valve 40 which is a part of the ink supply path 20 than in the air chamber 42 of the choke valve 40 to which the air flow path 70 is connected. When the negative pressure of the ink chamber 41 of the choke valve 40 increases, the flexible member 43 is deformed (shrinks) to the bottom surface 41a side due to the pressure difference with the air chamber 42, and as shown by the two-dot chain line in FIG. The valve 40 is closed. When the choke valve 40 is closed, the ink supply path 20 on the downstream side of the choke valve 40 is in a negative pressure state. Further, like the choke valve 40, the head tank 50 is also contracted.

Next, the valve 70a is opened to allow the air flow path 70 to communicate. Then, as described above, in the ink chamber 41 of the choke valve 40, a negative pressure obtained by reducing the pressure loss of the ink supply path 20 acts, so that the air chamber 42 of the choke valve 40 has a negative pressure rather than the ink chamber 41. And the choke valve 40 can be opened. When the choke valve 40 is opened, the ink is vigorously poured into the ink supply path 20 having a negative pressure, and the remaining bubbles and sediment components can be discharged from the nozzles of the inkjet head H all at once. At this time, by closing the valve 86a, the head tank 50 can be kept in a contracted state so as not to kill the momentum of the ink.
Therefore, according to this choke cleaning, the choke valve 40 can be opened and closed by using the suction force of the suction device SC by opening and closing the valve 70a.

  As described above, in the present embodiment, the air flow path 70 is provided, the ink discharge path 60 that connects the cap member CP and the suction device SC, and the ink supply path 20 that connects the ink cartridge CTR and the inkjet head H. The air chamber 42 of the provided choke valve 40 is connected and a valve 70a is provided in the air flow path 70 so that the ink discharge path 60 and the air chamber 42 of the choke valve 40 are communicated with each other. When the valve 70a is closed and the suction device SC is driven, the ink supply path 20 becomes negative pressure via the ink discharge path 60, and the negative pressure is higher in the ink chamber 41 of the choke valve 40 than in the air chamber 42. The choke valve 40 can be closed.

When the valve 70 a is opened and the suction device SC is driven, the ink supply path 20 becomes negative pressure via the ink discharge path 60, and the air chamber 42 of the choke valve 40 is also negative pressure via the air flow path 70. It becomes. Here, in the ink chamber 41 of the choke valve 40, a negative pressure obtained by reducing the pressure loss in the ink supply path 20 acts, so that the air chamber 42 of the choke valve 40 has a higher negative pressure than the ink chamber 41. The choke valve 40 can be opened.
Thus, by combining the air flow path 70 and the valve 70a and using the suction device SC for sucking ink as a power source, the choke valve 40 can be opened and closed without providing an additional actuator. For this reason, in this embodiment, a structure can be simplified and manufacturing cost can be reduced.

In this embodiment, the valve 70 a is closed, the air flow path 70 is disconnected, the valve 81 a is opened, and the pressure chamber 84 of the ink cartridge CTR and the air chamber of the choke valve 40 are connected via the air flow paths 81 and 85. 42, the choke valve 40 is closed, and the suction device SC is driven to perform the first cleaning in which only the ink in the ink supply path 20 on the downstream side of the choke valve 40 is replaced. .
In the present embodiment, the valve 81 a is closed, the air flow path 81 is disconnected, the valve 70 a is opened, and the ink discharge path 60 and the air chamber 42 of the choke valve 40 are connected via the air flow path 70. In this state, by driving the suction device SC, the choke valve 40 is opened by the pressure difference based on the flow path resistance difference between the ink supply path 20 and the air flow path 70, and the ink supply path on the upstream side of the choke valve 40. A second cleaning can be performed to replace up to 20 inks.
As described above, in the present embodiment, the first cleaning and the second cleaning can be selected. Therefore, the two types of cleaning are selectively used as necessary, and the ink jet head H is ejected while suppressing wasteful consumption of ink. Properties can be restored.

  In this embodiment, when a plurality of ink supply paths 20 are provided (see FIG. 1) and a plurality of choke valves 40 are provided, the air flow path 70 is branched downstream of the valve 70a, and a plurality of chokes are provided. By connecting to each of the air chambers 42 of the valve 40, the air chambers 42 of the plurality of choke valves 40 can be set to a negative pressure. Thus, in this embodiment, the choke valves 40 of all the ink supply paths 20 can be easily opened and closed simply by branching the air flow path 70, so that the structure can be simplified and the manufacturing cost can be reduced. be able to.

In the present embodiment, the valve 60a is provided in the ink discharge path 60, the buffer tank 61 is provided on the downstream side of the valve 60a, the valve 60a is closed, and the suction device SC is driven, whereby the negative pressure is applied to the buffer tank 61. Can be stored. Since the buffer tank 61 has a space volume larger than the space volume of the cap member CP, the inside of the cap member CP can be made negative pressure at a stroke by opening the valve 60a when necessary, and the cleaning time Can be shortened.
In the present embodiment, the air flow path 70 is connected to the upper portion 61 a of the buffer tank 61, thereby preventing ink that has flowed into the buffer tank 61 through the cap member CP from entering the air flow path 70. Can do.

  In the present embodiment, the self-sealing valve 30 that opens when the pressure of the ink supply path 20 is smaller than the atmospheric pressure and replenishes ink as needed is provided upstream of the choke valve 40. At this time, an appropriate negative pressure can be generated with respect to the inkjet head H. Thereby, the bubbles in the ink supply path 20 are expanded by the negative pressure, and the bubble discharge property can be improved.

  As described above, according to the above-described embodiment, the ink jet head H that ejects the ink supplied from the ink cartridge CTR containing the ink from the nozzles, and the ink supply that connects the ink cartridge CTR and the ink jet head H to each other. A path 20, an ink chamber 41 that forms part of the ink supply path 20, and an air chamber 42 that is separated from the ink chamber 41 via a flexible member 43. The flexible member 43 is deformed by the pressure difference, the choke valve 40 that opens and closes the ink supply path 20, the cap member CP that covers the nozzle, the suction device SC that sucks ink through the cap member CP, and the cap member CP. Between the ink discharge path 60 and the suction chamber SC, and between the ink discharge path 60 and the air chamber 42 of the choke valve 40. An air flow passage 70 to a valve 70a for opening and closing the air passage 70, by employing the printer PRT having the simplify the structure, manufacturing cost can be reduced.

  As mentioned above, although preferred embodiment of this invention was described referring drawings, this invention is not limited to the said embodiment. Various shapes, combinations, and the like of the constituent members shown in the above-described embodiments are examples, and various modifications can be made based on design requirements and the like without departing from the gist of the present invention.

  For example, in the above-described embodiment, the configuration in which the buffer tank 61 is provided in the ink discharge path 60 has been described, but a configuration in which the buffer tank 61 is not provided may be employed. In the case of a line head provided with a plurality of ink jet heads H, the space volume of the cap member CP also increases. Therefore, it is preferable to provide a buffer tank 61 and apply negative pressure at a stroke.

For example, in the above-described embodiment, the configuration in which the head tank 50 is provided in the ink supply path 20 has been described, but a configuration in which the head tank 50 is not provided may be employed.
Moreover, in the above-mentioned embodiment, although the structure which provides the choke valve 40 in the downstream of the self-sealing valve 0 was demonstrated, the structure which provides the choke valve 40 in the upstream of the self-sealing valve 30 may be employ | adopted. . By providing the choke valve 40 upstream of the self-sealing valve 30, it is possible to improve the bubble discharge performance of the self-sealing valve 30.

  For example, in the above-described embodiment, the configuration in which one choke valve 40 is provided in the ink supply path 20 has been described. However, a configuration in which a similar choke valve 40 is further provided on the upstream side of the choke valve 40 may be adopted. Good.

  For example, in the above-described embodiment, the configuration in which the pressurized air in the pressurizing chamber 84 of the ink cartridge CTR is sent and the choke valve 40 and the head tank 50 are operated as necessary has been described. In a situation where it is not required, a configuration in which pressurized air is directly sent from the pressurizing device 80 may be adopted.

For example, in the above-described embodiment, the configuration in which the choke valve 40 is provided with the operating pressure adjusting spring 44 that adjusts the operating pressure has been described, but a configuration in which the operating pressure adjusting spring 44 is not provided may be employed.
In the above-described embodiment, the configuration in which the operating pressure adjusting spring 54 for adjusting the operating pressure is provided in the head tank 50 has been described. However, a configuration in which the operating pressure adjusting spring 54 is not provided may be employed.

  In the above-described embodiment, the case where the liquid ejecting apparatus is the printer PRT has been described as an example. However, the liquid ejecting apparatus is not limited to the printer, and may be an apparatus such as a copying machine or a facsimile.

  Further, the liquid ejecting apparatus may employ a configuration in which liquid other than ink is ejected or discharged. The present invention can be applied to various liquid ejecting apparatuses including a liquid ejecting head that ejects a minute amount of liquid droplets, for example. In addition, a droplet means the state of the liquid discharged from the said liquid ejecting apparatus, and shall also include what pulls a tail in granular shape, tear shape, and thread shape. The liquid here may be any material that can be ejected by the liquid ejecting apparatus. For example, it may be in a state in which the substance is in a liquid phase, such as a liquid with high or low viscosity, sol, gel water, other inorganic solvents, organic solvents, solutions, liquid resins, liquid metals (metal melts ) And a liquid as one state of a substance, as well as a material in which particles of a functional material made of a solid such as a pigment or metal particles are dissolved, dispersed or mixed in a solvent. A typical example of the liquid is ink as described in the above embodiment. Here, the ink includes general water-based inks and oil-based inks, and various liquid compositions such as gel inks and hot melt inks.

CP cap member CTR ink cartridge (liquid container)
H Inkjet head (liquid jet head)
PRT printer (liquid ejecting device)
SC suction device 20 Ink supply path (liquid supply path)
30 Self-sealing valve 40 Choke valve 41 Ink chamber (liquid chamber)
42 Air chamber 43 Flexible member 50 Head tank (liquid reservoir)
51 Ink chamber (second liquid chamber)
52 Air chamber (second air chamber)
53 Flexible member (second flexible member)
60 Ink discharge path (liquid discharge path)
60a Valve (second switchgear)
61 Buffer tank 61a Upper part 70 Air flow path 70a Valve (opening / closing device)
80 Pressurizing device 81 Air flow path (second air flow path)
81a Valve (third switch)
84 Pressurization chamber
85 Air channel (third air channel)
86 Air channel (fourth air channel)
86a Valve (fourth switchgear)

Claims (9)

A liquid ejecting head that ejects liquid supplied from a liquid container that contains liquid from a nozzle;
A liquid supply path connecting the liquid container and the liquid jet head;
A liquid chamber that forms a part of the liquid supply path; and an air chamber that is separated from the liquid chamber via a flexible member, and the flexibility is determined by a pressure difference between the liquid chamber and the air chamber. A choke valve that deforms a member and opens and closes the liquid supply path;
A cap member covering the nozzle;
A suction device for sucking liquid through the cap member;
And the liquid discharge passage Ru communicated to said cap member and said suction device,
An air passage Ru communicates the air chamber of the liquid discharge path and the choke valve,
An opening and closing device for opening and closing the air flow path;
A second opening / closing device for opening and closing the liquid discharge path;
A buffer tank connected to the downstream side of the second opening / closing device in the liquid discharge path and having a predetermined space volume,
The air flow path communicates the liquid discharge path and the air chamber of the choke valve via the buffer tank.
A liquid ejecting apparatus. A plurality of the liquid supply paths are provided,
The choke valve is provided in each of the plurality of liquid supply paths,
The air flow path branches downstream from the opening / closing device and is connected to each of the air chambers of the plurality of choke valves.
The liquid ejecting apparatus according to claim 1. The buffer tank has a spatial volume larger than the spatial volume of the cap member .
The liquid ejecting apparatus according to claim 1, wherein: The air flow path is connected to the upper part of the buffer tank,
The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is a liquid ejecting apparatus. A pressurizing device for pressurizing air;
A second air flow path connecting between the pressurizing device and the air chamber of the choke valve;
A third opening / closing device for opening and closing the second air flow path,
The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is a liquid ejecting apparatus. The liquid container has a pressurizing chamber for pushing out the stored liquid to the liquid supply path,
A third air flow path connecting the pressurizing chamber of the liquid container and the second air flow path upstream of the third opening / closing device;
The liquid ejecting apparatus according to claim 5. The suction device is driven in a state where the opening / closing device is closed, the third switching device is opened, and the choke valve is closed by the pressure of the pressurizing chamber of the liquid container, and the liquid is supplied via the cap member. A first cleaning to suck,
With the opening and closing device opened and the third opening and closing device closed, the suction device is driven and the choke valve is opened by a pressure difference based on a flow path resistance difference between the liquid supply path and the air flow path. The second cleaning that sucks the liquid through the cap member can be selected.
The liquid ejecting apparatus according to claim 6. A second liquid chamber which is provided downstream of the choke valve and forms a part of the liquid supply path; and a second liquid chamber separated from the second liquid chamber via a second flexible member. A liquid that includes two air chambers, deforms the second flexible member by a pressure difference between the second liquid chamber and the second air chamber, and changes a space volume of the second liquid chamber. A reservoir,
A fourth air flow path connecting the second air chamber of the liquid reservoir and the pressurizing device;
A fourth opening / closing device that opens and closes the fourth air flow path,
The liquid ejecting apparatus according to any one of claims 5 to 7 . A self-sealing valve that is provided upstream of the choke valve and opens the liquid supply path by the difference between the pressure of the liquid supply path and atmospheric pressure;
The liquid ejecting apparatus according to claim 1, wherein the liquid ejecting apparatus is a liquid ejecting apparatus.

Images