JP2011235508A - Tube pump, and liquid injection device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tube pump which can suck and discharge a liquid from one end of a tube by a simple constitution, and to provide a liquid injection device.SOLUTION: The liquid injection device includes the tube 62, a frame 63 and a pressing roller 67. The tube 62 has an opening part 62a formed on one end side in a length direction which enables suction and discharge of the ink, and a blocking part 62b formed on the other end side in the length direction. Moreover, at least an intermediate part 62c in the length direction has an elasticity. The frame 63 has a supporting surface 63d of a circular arc shape in cross section which can support the intermediate part 62c of the tube 62 along the length direction. The pressing roller 67 can freely perform circular motion around a driving shaft 65 to be the arc center of the supporting surface 63d between a holding region B and a non-holding region A. The pressing roller 67 can perform circular motion in either one direction of a direction to approach the opening part 62a in the length direction of the tube 62 and a direction to approach the blocking part 62b. The pressing roller 67 moves in the holding region B by performing circular motion in one direction, and then further moves to the non-holding region A by performing circular motion in one direction.

Description

  The present invention relates to a tube pump and a liquid ejecting apparatus capable of sucking and discharging a liquid.

  Conventionally, inkjet printers are widely known as one of liquid ejecting apparatuses. In this printer, printing is performed by ejecting ink (liquid) supplied from an ink cartridge (liquid supply source) from a nozzle formed in a recording head (liquid ejecting head) onto a recording medium as a target. Yes.

  In such a printer, recently, as described in, for example, Patent Document 1, ink is sucked and discharged by a circular movement while a contact member (pressing member) crushes a flexible tube. Tube pumps are known.

JP 2004-137940 A

  By the way, in the case of the tube pump of Patent Document 1, ink is sucked from one end of the tube and ejected from the other end of the tube as the abutting member moves circularly in one direction. However, in such a tube pump, there are cases where it is desired to perform both suction and discharge of ink from one end side of the tube. However, in the case of the tube pump of Patent Document 1, in order to eject ink from one end side where ink has been sucked, the contact member must be circularly moved in the direction opposite to that at the time of sucking, and the configuration becomes complicated. There was a problem that.

  The present invention has been made in view of the above problems, and an object thereof is to provide a tube pump and a liquid ejecting apparatus that can suck and discharge liquid from one end of the tube with a simple configuration.

  In order to achieve the above object, the tube pump of the present invention is provided with an opening that allows suction and discharge of liquid at one end in the length direction and a blocking portion at the other end in the length direction. A tube having at least an intermediate portion in the length direction having elasticity, a pump frame having a support surface having an arcuate cross section capable of supporting the intermediate portion of the tube along the length direction, and the intermediate portion. Circular movement freely between a closed section that crushes and closes the inner space of the tube between the support surface and a non-closed section that is different from the closed section around an axis that is the arc center of the support surface. A pressing member, and the pressing member is capable of circular motion in either one of a direction approaching the opening and a direction approaching the closing portion in the length direction of the tube, It is, after moving the block section with circular movement in the one direction, move further above with circular motion in one direction to the non-block section.

  According to this structure, while a press member moves circularly to one direction, while moving a blockage area, it moves from a blockage area to a non-blocking area. Then, the tube whose middle portion is crushed by the pressing member changes the volume of the internal space on the opening side with respect to the crushed position, and can suck and discharge liquid from the opening. That is, for example, when the pressing member is located in the closed section and the tube is crushed and circularly moves in one direction approaching the closed portion, in the internal space on the opening side of the crushed position in the tube, Since the volume increases to a negative pressure, the liquid is sucked from the opening. At that time, in the internal space closer to the closed portion than the crushed position in the tube, the volume is reduced and the gas in the internal space is compressed. Then, when the pressing member moves to the non-blocking section by making a circular motion in one direction closer to the blocking portion from the state, the liquid is opened by the pressure of the gas compressed in the internal space on the blocking portion side. The liquid is discharged from the opening. The one direction in which the pressing member moves circularly may be one direction opposite to the above case (one direction approaching the closing part) (one direction approaching the opening part). That is, for example, if the pressing member is located in the closed section and the tube is crushed and circularly moves in one direction approaching the opening, the inner space closer to the opening than the crushed position in the tube Since the volume decreases and the pressure in the internal space increases, the liquid is discharged from the opening by the pressure. Moreover, since the volume increases in the internal space closer to the closed portion than the crushed position in the tube, the internal space is decompressed. Then, when the pressing member is displaced to the non-occlusion position by circular movement in one direction closer to the opening from that state, the liquid is drawn into the decompressed internal space on the side of the obstruction, thereby opening the opening. Liquid is aspirated from. Therefore, the liquid can be sucked and discharged from one end of the tube with a simple configuration.

  In the tube pump of the present invention, the pump frame has a cutout portion in which a part of the support surface is cut out in a circumferential direction centering on the axis, and the non-blocking section includes the pressing member It is a section with respect to the notch, and the closed section is a section in which the pressing member presses the tube against the support surface to block the internal space of the tube.

  According to this configuration, by causing the pressing member to make a circular motion about the axis, the pressing member moves alternately between the non-blocking section with respect to the notch and the blocking section with respect to the support surface. Therefore, the suction and discharge of the liquid from the opening can be performed alternately by causing the pressing member to continuously perform the circular motion in one direction. That is, for example, even when a small tube pump is used, it is possible to easily supply a liquid having a single discharge amount or more.

  In the tube pump of the present invention, the pressing member is filled with liquid in the internal space on the opening side in the length direction of the tube from a position where the pressing member is crushed by the pressing member in an intermediate portion of the tube. In this state, the circular motion of the pressing member is stopped in the closed section.

  According to this configuration, when the pressing member stops in the closed section and closes the internal space of the tube, the gas in the internal space on the closed portion side is separated from the liquid in the internal space on the open portion side. be able to. Therefore, the gas can be prevented from being dissolved into the liquid.

  The liquid ejecting apparatus of the present invention includes a liquid ejecting head that ejects liquid to a target, and a liquid supply flow that supplies the liquid from an upstream side that is a liquid supply source side to a downstream side that is the liquid ejecting head side. A one-way valve provided at a first position in the liquid supply flow path and allowing the liquid to pass from the upstream side to the downstream side, and downstream from the first position in the liquid supply flow path. A tube pump configured as described above, wherein the liquid is sucked and discharged from the second position by connecting the opening to a second position on the side;

  In general, when the liquid in the liquid ejecting head evaporates and thickens, the liquid ejecting head is vigorously discharged to eliminate the liquid ejection failure (choke cleaning). For example, in order to pressurize the liquid on the upstream side of the liquid ejecting head and supply the liquid vigorously to the liquid ejecting head, a valve is provided between the liquid supply flow path or the pump and the liquid supply flow path. A complicated configuration for valve opening and closing control was required. In this respect, according to this configuration, the liquid can be vigorously supplied to the liquid ejecting head by ejecting the liquid vigorously from the tube pump to the liquid supply flow path. That is, for example, when the pressing member performs a circular motion in one direction from the state at the closed position toward the closed portion, the liquid is ejected vigorously based on the pressure of the compressed gas. Therefore, the liquid ejecting head is cleaned by discharging the thickened liquid by vigorously discharging the liquid from the tube pump and supplying it to the liquid ejecting head with a simple configuration in which the pressing member is circularly moved in one direction. Can do.

1 is a schematic diagram of a printer according to a first embodiment. FIG. 2 is a schematic diagram of an ink supply system. The schematic diagram of the maintenance pump at the time of a suction drive start. The schematic diagram of the maintenance pump at the time of suction drive. The schematic diagram of the maintenance pump at the time of completion | finish of suction drive. The schematic diagram of the maintenance pump at the time of discharge drive. The schematic diagram of the maintenance pump of 2nd Embodiment. The schematic diagram of the maintenance pump at the time of the drive stop of 3rd Embodiment. The schematic diagram of the maintenance pump at the time of suction drive.

(First embodiment)
Hereinafter, a first embodiment in which a liquid ejecting apparatus of the invention is embodied in an ink jet printer will be described with reference to FIGS. In the following description, the terms “left-right direction” and “up-down direction” refer to the left-right direction indicated by arrows in FIG. Further, when referring to the “front-rear direction”, the direction orthogonal to the paper surface of FIG.

  As shown in FIG. 1, an ink jet printer (hereinafter referred to as “printer”) 11 as a liquid ejecting apparatus includes a transport unit 13 for transporting a sheet 12 as a target, and a printing for printing on the sheet 12. And a recording head unit 15.

  The transport unit 13 includes a rectangular plate-shaped platen 17 that is long in the left-right direction. A drive roller 18 extending in the front-rear direction is disposed on the right side of the platen 17 so as to be rotationally driven by a drive motor 19, while a driven roller 20 extending in the front-rear direction is disposed on the left side of the platen 17 so as to be rotatable. Further, a tension roller 21 extending in the front-rear direction is rotatably disposed below the platen 17.

  An endless transport belt 22 having a large number of through holes is wound around the drive roller 18, the driven roller 20, and the tension roller 21 so as to surround the platen 17. In this case, the tension roller 21 is urged downward by a spring member (not shown), and by applying tension to the conveyor belt 22, looseness of the conveyor belt 22 is suppressed.

  Then, when the driving roller 18 is rotationally driven in the clockwise direction when viewed from the front side, the conveying belt 22 is rotated in the clockwise direction when the outer side of the driving roller 18, the tension roller 21, and the driven roller 20 is viewed from the front side. It has become. Further, when the sheet 12 is at a position facing the upper surface of the platen 17, the sheet 12 is sucked to the platen 17 side through the conveying belt 22 by a suction unit (not shown), and is conveyed from the upstream left side to the downstream right side. It has come to be.

  A pair of upper and lower paper feed rollers 23 for feeding a plurality of unprinted paper sheets 12 one by one onto the transport belt 22 one by one is provided on the upper left side of the driven roller 20. On the other hand, on the diagonally upper right side of the driving roller 18, a pair of upper and lower paper discharge rollers 24 for discharging the printed paper 12 one by one from the transport belt 22 are provided.

  As shown in FIGS. 1 and 2, the recording head unit 15 includes a plurality of (four in the present embodiment) recording heads 26 to 29 extending in the front-rear direction and spaced in the left-right direction. Is provided. In addition, on the nozzle formation surfaces 26a to 29a that are the lower surfaces of the recording heads 26 to 29, a large number of nozzles 30 are regularly formed at predetermined intervals in the front-rear direction so as to form nozzle rows along the front-rear direction. It is open. The nozzles 30 thus configured are supplied with the same type of ink (liquid) for each of the recording heads 26 to 29 and ejected from the nozzles 30.

  That is, as shown in FIG. 2, the first recording head 26 receives black ink from an ink cartridge 31 serving as a liquid supply source containing black ink via an ink flow path 32 serving as a liquid supply flow path. Is connected to the ink supply device 33. Similarly, the second to fourth recording heads 27 to 29 are connected to an ink supply device 33 that supplies ink from ink cartridges 31 containing inks of cyan, magenta, and yellow, respectively.

  However, since the configuration of the ink supply device 33 that supplies ink from each ink cartridge 31 to each recording head 26 to 29 is the same, FIG. 2 shows one ink supply device that supplies ink to the first recording head 26. Only 33 is shown together with the first recording head 26 and the ink cartridge 31. In the following description, the first recording head 26 and the ink supply device 33 that supplies ink to the first recording head 26 shown in FIG. 2 will be described as an example.

  As shown in FIG. 2, a reservoir 36 communicating with the downstream side of the ink flow path 32 is formed in the first recording head 26 so as to extend in the front-rear direction along the nozzle row. A plurality of branch flow paths 35 individually corresponding to the nozzles 30 are branched from a plurality of positions in the extending direction. The branch channel 35 includes a cavity 37 that communicates with the nozzle 30, and a communication channel 38 that communicates the cavity 37 and the reservoir 36. Further, a piezoelectric element (not shown) is disposed at a position adjacent to the cavity 37 in the first recording head 26. The piezoelectric element contracts and expands to change the volume of the cavity 37, so that ink is ejected from the nozzle 30.

  The ink cartridge 31 includes a flexible ink pack 46 that stores ink, and a case 47 that stores the ink pack 46. In addition, a pressure pump 49 is connected to the case 47 via an air flow path 48, and an upstream end of the ink flow path 32 is connected to the ink pack 46. The pressure pump 49 supplies air into the case 47 via the air flow path 48 so that the ink pack 46 is crushed and the ink in the ink pack 46 is supplied to the ink flow path 32. It has become.

  In addition, the pressure adjustment position PT as the first position in the ink flow path 32 allows the ink to pass from the upstream side to the downstream side as the downstream pressure decreases, and adjusts the pressure in the ink flow path 32. A one-way valve 51 is provided. In other words, the one-way valve 51 includes a storage chamber 52 that primarily stores ink pressurized and supplied from the ink cartridge 31, and a pressure chamber 53 that is positioned downstream of the storage chamber 52. The storage chamber 52 and the pressure chamber 53 are separated by a partition wall portion 54, and a valve hole 54 a is formed through the partition wall portion 54. A valve body 56 that is urged in the valve closing direction by the spring 55 and contacts the partition wall portion 54 from the storage chamber 52 side is disposed in the valve hole 54 a, and the valve body 56 resists the urging force of the spring 55. Accordingly, the storage chamber 52 and the pressure chamber 53 communicate with each other by moving in the valve opening direction.

  That is, when ink is ejected from the nozzle 30 and consumed, the pressure chamber 53 is depressurized, and the film 57 is bent and deformed toward the pressure chamber 53 based on the pressure difference between the pressure chamber 53 and the atmosphere. When the bending force becomes larger than the urging force of the spring 55, the valve body 56 moves to the valve opening position away from the partition wall 54, and the pressurized ink in the storage chamber 52 flows into the pressure chamber 53 side. . When ink flows into the pressure chamber 53 and the chamber pressure is increased, the urging force of the spring 55 is overcome and the valve body 56 is moved again to the valve closing position where it abuts against the partition wall portion 54.

  As described above, the one-way valve 51 is opened by the pressure reduction on the downstream side of the valve body 56, whereas when the upstream side is pressurized, the valve body 56 receives a force in the closing direction, so that the valve is opened. Keep valve closed without valve. Similarly, when the downstream side is pressurized, the film 57 bends and deforms in the direction of increasing the volume of the pressure chamber 53, so that the valve body 56 closes without receiving a force in the valve opening direction from the film 57. Maintain valve status. Furthermore, since the upstream ink is pressurized by the pressurizing pump 49, the upstream side of the valve body 56 is not depressurized. That is, the one-way valve 51 is a valve that opens only when the downstream side is depressurized.

  A part of the pressure chamber 53 is constituted by a film 57 made of a flexible material (for example, synthetic resin or rubber). For example, a cantilever metal piece (for example, comb teeth) that can be displaced together with the film 57 is used. A piece of metal piece) is arranged at the contact point of the valve body 56.

  A maintenance pump 61 as a tube pump capable of sucking and discharging ink by changing the pressure in the ink flow path 32 is provided at a transformation position PH as a second position downstream of the pressure adjustment position PT. It is connected.

  The maintenance pump 61 is a pump that can pressurize the ink in the recording head 26. That is, although the pressurizing pump 49 is provided separately from the maintenance pump 61, pressurization by the pressurizing pump 49 is blocked by the one-way valve 51, and the pressurizing force cannot be transmitted to the recording head 26. Therefore, in order to perform maintenance of the recording head 26, a maintenance pump 61 capable of pressurizing the ink in the recording head 26 is required in addition to the pressurizing pump 49.

  As shown in FIG. 3, the maintenance pump 61 includes an elastic tube 62, a frame 63 as a pump frame that supports the tube 62, and a pressing mechanism 64 that can press the tube 62.

  The tube 62 is connected to the ink flow path 32 as an opening 62a capable of sucking and discharging ink, while the end on the base end side, which is one end side in the length direction, is connected to the other side in the length direction. The end portion on the tip side, which is the end side, is a closed portion 62b that cannot suck and discharge ink. In the length direction of the tube 62, an intermediate portion 62 c that is a portion pressed by the pressing mechanism 64 is provided between the opening portion 62 a on the proximal end side and the closing portion 62 b on the distal end side. It should be noted that the portion of the tube 62 from the proximal end side opening 62a to the intermediate portion 62c is from the opening 62a so that the proximal end side opening 62a is positioned lower in the direction of gravity than the intermediate portion 62c. It is provided so as to extend obliquely upward. In the tube 62, the distal end side blocking portion 62b is provided at an upper position in the gravity direction than the proximal end side opening portion 62a.

  The frame 63 has a base end portion for supporting a base end side portion provided with the opening 62 a of the tube 62, a tip end side portion provided with the closing portion 62 b, and an intermediate portion 62 c in the length direction of the tube 62. It has a support part 63a, a tip support part 63b, and an intermediate support part 63c. The proximal end support portion 63a and the distal end support portion 63b in the frame 63 are formed in a cylindrical shape so as to support the proximal end side portion and the distal end side portion of the tube 62 in an inserted state.

  Further, the intermediate support portion 63c in the frame 63 is a plate-like body that connects the base end support portion 63a and the distal end support portion 63b, and the outer peripheral side in a state where the intermediate portion 62c of the tube 62 is curved in an arc shape. It is formed to be bent in a circular arc shape so as to be supported from above. That is, the intermediate support part 63c is cut out in a circumferential direction centered on the arc center of the support surface 63d, which is an inner surface of the intermediate support part 63c, with a part of the ring being cut out to form a C-shaped cross section. The cut portion is a notch 63e. And the intermediate part 62c of the tube 62 is supported along the length direction by the support surface 63d of the intermediate | middle support part 63c curved in circular arc shape in cross section.

  In addition, a pressing mechanism 64 is disposed at an inner (inner peripheral side) position of the intermediate portion 62c of the tube 62 that is supported in an arcuate shape by the intermediate support portion 63c of the frame 63. The pressing mechanism 64 rotates on a rotating plate 66 that can rotate around a drive shaft 65 as an axis that is the center of the arc of the support surface 63d, and on the tip of a tongue piece 66a that protrudes radially outward of the rotating plate 66. A pressing roller 67 serving as a pressing member is provided. The pressing roller 67 is provided so as to be rotatable about the rotation shaft 68. The pressing roller 67 presses the intermediate portion 62 c of the tube 62 from the inner peripheral side toward the intermediate support portion 63 c side of the frame 63. That is, the pressing roller 67 is disposed so as to be able to crush the inner space of the tube 62 by sandwiching the intermediate portion 62c of the tube 62 with the support surface 63d of the intermediate support portion 63c in the frame 63.

  That is, the inside of the tube 62 (specifically, the intermediate portion 62c) is a base on the opening 62a side, with the pressing point 62d being a position crushed by the pressing roller 67 and the intermediate support portion 63c of the frame 63 as a boundary. The inner space on the end side is an ink chamber 69. Further, the internal space on the distal end side closer to the closing portion 62b than the pressing point 62d is a gas chamber 70. The ink chamber 69 communicates with the ink flow path 32 through the opening 62a, and therefore is filled with ink supplied from the ink flow path 32 side. On the other hand, gas (for example, air) is accommodated in the gas chamber 70.

  Then, when the drive shaft 65 rotates with the driving of the pressing motor 71 (see FIG. 2), the pressing roller 67 moves circularly in the direction (counterclockwise direction) indicated by the white arrow in FIG. It is like that. That is, when the pressing roller 67 circularly moves in a direction approaching the closing portion 62b on the distal end side while maintaining the state where the tube 62 is crushed, the volume of the ink chamber 69 increases as shown in FIG. The pressing point 62d moves in the direction in which the volume of the chamber 70 decreases.

  Specifically, as shown in FIG. 3, when the pressing roller 67 located at the suction start position P1 moves circularly to the suction end position P2 shown in FIG. 5, the volume of the ink chamber 69 increases and the ink is increased. Ink is sucked from the flow path 32. On the other hand, the volume of the gas chamber 70 decreases, and the stored gas is compressed.

  Furthermore, when the pressing roller 67 further circularly moves from the suction end position P2 shown in FIG. 5 and is positioned in the non-clamping area A (see FIG. 3) as a non-blocking section with respect to the notch 63e as shown in FIG. 62 is released. Then, the pressure of the gas accommodated in the gas chamber 70 and compressed acts on the ink in the ink chamber 69. Therefore, the ink moves to the opening 62 a side so as to be pushed by the gas and is ejected into the ink flow path 32. That is, the non-clamping region A is a position where the pressing roller 67 is not opposed to the intermediate support part 63c via the tube 62, and the intermediate part 62c of the tube 62 cannot be clamped between the intermediate support part 63c. is there.

  When the pressing roller 67 further moves in a circular motion and moves to the clamping region B (see FIG. 3) as a closed section where the tube 62 can be clamped together with the intermediate support portion 63c, as shown in FIG. The tube 62 (specifically, the intermediate portion 62c) is pressed against the support surface 63d of the intermediate support portion 63c and sandwiched. That is, the clamping region B is a position where the pressing roller 67 is opposed to the intermediate support portion 63c via the tube 62, and is a position where the inner space can be closed by pressing the tube 62 toward the intermediate support portion 63c.

  In the present embodiment, one non-clamping area A and one clamping area B are positioned on the circular motion locus of the pressing roller 67, and the clamping area B is centered on the drive shaft 65 rather than the non-clamping area A. The region length in the circumferential direction is long. Then, the maintenance pump 61 is driven to discharge and drive by causing the pressing motor 71 to rotationally drive the drive shaft 65 and displace the pressing roller 67 sequentially through the non-clamping area A and the clamping area B. It has become.

  Further, as shown in FIG. 2, the printer 11 is provided with a control unit 72 that performs overall control of the operating state of the printer 11. The control unit 72 drives and controls a piezoelectric element (not shown), a pressure pump 49, and a pressing motor 71 provided in each of the recording heads 26 to 29, and performs printing and cleaning processing.

Next, the operation of the printer 11 configured as described above will be described below.
When printing is started in the printer 11, the control unit 72 creates an ink ejection timing for each nozzle 30 based on the print data, and drives the piezoelectric element based on the ejection timing. Ink is ejected from 30. In other words, the ink ejected from each nozzle 30 adheres to the paper 12 supported by the transport belt 22 and transported, whereby the paper 12 is printed.

  When ink is ejected from the nozzle 30 and consumed, the reduced pressure accompanying the decrease in ink is transmitted to the one-way valve 51 via the reservoir 36 and the ink flow path 32. Then, the valve body 56 moves to the valve opening position against the urging force of the spring 55, and the ink in the storage chamber 52 flows into the pressure chamber 53 side. When ink flows into the pressure chamber 53 and the chamber pressure increases, the urging force of the spring 55 overcomes and the valve body 56 moves to the valve closing position again.

  Accordingly, since the one-way valve 51 allows ink to pass from the upstream side to the downstream side in accordance with the pressure reduction on the downstream side, the consumed ink is supplied from the ink cartridge 31 side.

  By the way, if the period during which ink is not ejected from the nozzles 30 without printing is increased, the ink may evaporate from the nozzles 30 to increase the viscosity of the ink, or the meniscus position may increase. The rise in the meniscus position may occur not only in the evaporation of ink but also in other situations such as when the printer 11 receives an impact or when the end of the paper 12 contacts the nozzle 30.

  Therefore, the control unit 72 executes the cleaning process when, for example, a cleaning process execution command is received from a user (not shown) from the user or when it is determined that a predetermined time has passed since the previous cleaning process. It is assumed that the pressing roller 67 of the maintenance pump 61 is located at the suction start position P1 in the clamping region B during printing or standby during non-cleaning processing.

  Now, the control unit 72 drives the pressing motor 71 to cause the pressing roller 67 to circularly move in one direction around the drive shaft 65. That is, the pressing roller 67 located at the suction start position P1 moves the clamping area B to the suction end position P2 side along the direction indicated by the white arrow and moves to the non-clamping area A. It passes through and returns to the suction start position P1.

  Specifically, during the movement from the suction start position P1 to the suction end position P2, the volume of the ink chamber 69 increases, so the maintenance pump 61 is driven to suck and sucks ink from the ink flow path 32.

  When the maintenance pump 61 is driven to suck, ink is sucked from the nozzle 30 side downstream of the transformation position PH in the ink flow path 32. Further, the negative pressure accompanying the suction drive of the maintenance pump 61 also acts on the upstream side of the transformation position PH. Therefore, the film 57 is displaced in the direction in which the volume of the pressure chamber 53 decreases, and the one-way valve 51 is opened, so that ink is also supplied from the ink cartridge 31 side.

  When the pressing roller 67 further moves circularly from the suction end position P2 and moves to the non-clamping area A, the maintenance pump 61 is driven to discharge. That is, the pressure of the gas in the gas chamber 70 acts on the ink in the ink chamber 69, and the ink in the ink chamber 69 is discharged into the ink flow path 32.

  Meanwhile, the one-way valve 51 provided on the upstream side of the transformation position PH in the ink flow path 32 opens when the pressure is reduced from the downstream side, but closes when pressurized from the downstream side. Maintain valve status. For this reason, when ink is discharged from the maintenance pump 61, the one-way valve 51 is closed, so that it is vigorously supplied to the recording head 26 side, which is downstream of the pressure adjustment position PT.

  Therefore, when the maintenance pump 61 is driven to discharge, the ink that has been thickened in the vicinity of the nozzle 30 or the ink mixed with bubbles is discharged together with the ink supplied from the maintenance pump 61 side, and the recording head 26 is cleaned.

And the control part 72 stops the drive of the press motor 71 so that the press roller 67 may be located in the suction start position P1.
According to the first embodiment, the following effects can be obtained.

  (1) The pressing roller 67 moves in the clamping region B by circular movement in one direction, and moves from the clamping region B to the non-clamping region A. Then, the volume of the ink chamber 69 in the tube 62 in which the intermediate portion 62c is crushed by the pressing roller 67 changes to the base end side (opening 62a side) from the pressing point 62d that is the crushed position. Thus, ink can be sucked and discharged from the opening 62a on the base end side. That is, for example, when the pressing roller 67 is located in the clamping region B and the tube 62 is crushed and circularly moves in one direction approaching the closing portion 62b on the distal end side, the opening 62a is more than the pressing point 62d in the tube 62. Since the volume of the ink chamber 69 on the side increases to a negative pressure, the ink is sucked from the opening 62a on the base end side. At that time, the volume of the gas chamber 70 on the distal end side (closed portion 62b side) of the pressing point 62d in the tube 62 is reduced, and the gas in the gas chamber 70 is compressed. Then, when the pressure roller 67 is displaced in the non-clamping area A by circular movement in one direction approaching the closed portion 62b from that state, the ink is compressed by the pressure of the gas compressed in the gas chamber 70 on the closed portion 62b side. Is pushed back toward the opening 62a, and ink is ejected from the opening 62a. Therefore, ink can be sucked and discharged from one end of the tube 62 with a simple configuration.

  (2) By causing the pressing roller 67 to circularly move around the drive shaft 65, the pressing roller 67 alternately moves between the non-clamping area A for the notch 63e and the clamping area B for the support surface 63d. Accordingly, the suction and ejection of the ink from the opening 62a can be alternately executed by circularly moving the pressing roller 67 continuously in one direction. That is, for example, even when a small maintenance pump 61 is used, it is possible to easily supply ink that exceeds a single discharge amount.

  (3) When the pressing roller 67 stops in the clamping region B and closes the internal space of the tube 62, the gas in the gas chamber 70 on the distal end side (closed portion 62b side) and the proximal end side (opening portion 62a). The ink in the ink chamber 69 can be separated. Therefore, the gas can be prevented from being dissolved into the ink.

  (4) Generally, when the ink in the recording heads 26 to 29 evaporates and thickens, the ink ejection failure is eliminated by ejecting the ink from the recording heads 26 to 29 (choke). cleaning). For example, in order to pressurize the ink on the upstream side of the recording heads 26 to 29 and to supply the ink to the recording heads 26 to 29 side by side, the ink channel 32 or the maintenance pump 61 and the ink channel 32 are interposed. In addition to providing a valve, a complicated configuration for opening / closing control of the valve is required. In that respect, by ejecting ink from the maintenance pump 61 to the ink flow path 32, the ink can be vigorously supplied to the recording heads 26 to 29. That is, when the pressing roller 67 performs a circular motion in one direction from the state positioned in the clamping region B toward the opening 62a, ink is ejected vigorously based on the pressure of the compressed gas. Accordingly, the ink is vigorously discharged from the maintenance pump 61 and supplied to the recording heads 26 to 29 with a simple configuration in which the pressing roller 67 is circularly moved in one direction, whereby the thickened ink is discharged and the recording heads 26 to 26 are discharged. 29 cleaning can be performed.

  (5) By clamping the tube 62 with the support surface 63d and the pressing roller 67, the displacement of the tube 62 accompanying the displacement of the pressing roller 67 can be suppressed and the tube 62 can be crushed. Moreover, since the tube 62 can be crushed by circularly moving the pressing roller 67 by setting the support surface 63d to have an arc shape in cross section, the configuration of the pressing roller 67 can be simplified.

  (6) In the tube 62, the blocking portion 62b on the distal end side is located above the proximal end opening portion 62a in the gravity direction, so that ink having a mass larger than that of the gas enters the distal end side (the blocking portion 62b side). Can be suppressed. Furthermore, the possibility that gas is discharged from the opening 62a on the base end side can be reduced.

  (7) By moving the pressing roller 67 to the distal end side (closed portion 62b side) while maintaining the state where the tube 62 is closed, ink suction and gas compression can be performed simultaneously. Accordingly, the recording heads 26 to 29 can be quickly cleaned.

  (8) Since the maintenance pump 61 discharges the ink sucked while the pressing roller 67 moves from the suction start position P1 to the suction end position P2, the amount of ink to be discharged is easily controlled according to the momentum of the pressing roller 67. can do.

(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment differs from the first embodiment only in that the shape of the frame is changed, and the other components are the same, so the same components are the same. A detailed description thereof will be omitted by attaching a reference numeral.

  As shown in FIG. 7, a frame 76 as a pump frame in the maintenance pump 75 as a tube pump has a proximal end portion provided with an opening 62a and a distal end portion provided with a closing portion 62b. The tube 62 includes a base end support portion 76a, a distal end support portion 76b, and an intermediate support portion 76c that support the intermediate portion 62c in the length direction of the tube 62, respectively.

  The proximal end support portion 76a and the distal end support portion 76b are formed in a cylindrical shape so as to support the proximal end side portion and the distal end side portion of the tube 62 in an inserted state. Further, the intermediate support portion 76c is a plate-like body that connects the base end support portion 76a and the distal end support portion 76b, and supports the intermediate portion 62c of the tube 62 from the outer peripheral side in a curved state. Are bent into a circular arc shape in cross section. In other words, the intermediate support portion 63c has a ring-shaped cutout to form an arched cross section, and a portion that is notched in the circumferential direction around the arc center of the support surface 76d that is the inner surface of the intermediate support portion 76c. It is set as the notch part 76e. And the intermediate part 62c of the tube 62 is supported along the length direction by the support surface 76d inside the intermediate support part 76c curved in a semicircular arc shape in cross section.

  The tube 62 has a proximal end side opening 62 a connected to the ink flow path 32, and a distal end side blocking portion 62 b located above the proximal end side opening 62 a in the gravity direction. Similarly, the positional relationship between the blocking portion 62b on the distal end side and the intermediate portion 62c is such that the blocking portion 62b on the distal end side is positioned higher than the intermediate portion 62c on the proximal end side than the blocking portion 62b. Yes. When viewed from the whole tube, the tube 62 is arranged so as to be gradually positioned at an upper position in the direction of gravity from the proximal end side opening 62a toward the distal end side closing portion 62b in the length direction. Yes.

  In addition, a pressing mechanism 64 is provided on the inner side (inner peripheral side) position of the intermediate support portion 76c that is supported while being curved in an arc shape so that the drive shaft 65 is positioned at the arc center of the support surface 76d. . Then, the pressing roller 67 moves between the non-clamping area A against the notch 76e and the clamping area B that presses the tube 62 against the support surface 76d by making a circular motion about the drive shaft 65. . In the present embodiment, one non-clamping area A and one clamping area B are positioned on the circular movement locus of the pressing roller 67, and the non-clamping area A is equal to or greater than the clamping area B (A ≧ B). Yes.

Next, the operation of the maintenance pump 75 configured as described above will be described below.
When the maintenance pump 75 is stopped, the pressing roller 67 is positioned at the suction start position P1 that closes the proximal end side of the intermediate portion 62c of the tube 62.

  Now, the control unit 72 drives the pressing motor 71 to cause the pressing roller 67 to circularly move in one direction around the drive shaft 65. That is, the pressing roller 67 located at the suction start position P1 moves the clamping area B along the direction indicated by the white arrow (clockwise direction) toward the suction end position P2 and moves to the non-clamping area A. Further, it passes through the non-clamping area A and returns to the suction start position P1 again.

  Specifically, while the pressing roller 67 moves from the suction start position P1 to the suction end position P2, the pressing point 62d moves toward the tip side. Therefore, the volume of the ink chamber 69 increases and ink flows from the ink flow path 32 (suction drive). On the other hand, since the volume of the gas chamber 70 decreases, the gas in the gas chamber 70 is compressed.

  Further, when the pressing roller 67 further moves circularly from the suction end position P2 and moves to the non-clamping area A, the maintenance pump 61 is driven to discharge. That is, the pressure of the gas compressed in the gas chamber 70 acts on the ink in the ink chamber 69, and the ink in the ink chamber 69 is discharged into the ink flow path 32.

And the control part 72 will stop the drive of the press motor 71 so that this press roller 67 may be located in the suction start position P1, if the press roller 67 is rotated once.
According to the said 2nd Embodiment, in addition to the effect of (1)-(8) in 1st Embodiment, the following effects can be acquired further.

  (9) In the tube 62, the closing portion 62b on the distal end side is positioned above the intermediate portion 62c in the direction of gravity, and the intermediate portion 62c is positioned above the proximal end side opening 62a. Yes. Therefore, for example, even when ink enters the gas chamber 70, the ink that has entered enters the side closer to the ink chamber 69, which is the lower side in the direction of gravity. Therefore, the possibility that the gas in the gas chamber 70 is discharged from the opening 62 a below the ink chamber 69 can be further reduced.

(Third embodiment)
Next, a third embodiment of the present invention will be described with reference to FIGS. The third embodiment is different from the first embodiment only in that the configuration of the maintenance pump is changed, and the other configurations are the same, so the same components are the same. A detailed description thereof will be omitted by attaching a reference numeral.

  As shown in FIG. 8, a frame 81 as a pump frame in a maintenance pump 80 as a tube pump has a proximal end portion provided with an opening 62a and a distal end portion provided with a closing portion 62b. A proximal end support portion 81a, a distal end support portion 81b, and an intermediate support portion 81c that respectively support the intermediate portion 62c are provided.

  The intermediate support portion 81c has a support surface 81d that restricts movement of the tube 62 in the outer direction, and is formed in a cylindrical shape. Further, the proximal end support portion 81a and the distal end support portion 81b are formed in a cylindrical shape so as to cover the proximal end side portion and the distal end side portion of the tube 62 protruding from the intermediate support portion 81c.

  The proximal end portion of the tube 62 is provided obliquely so that the opening 62a at the proximal end portion is connected to the ink flow path 32 and is directed upward in the direction of gravity. In the tube 62, the intermediate portion 62c is positioned above the proximal end portion in the direction of gravity, and the distal end portion is positioned above the intermediate portion 62c in the direction of gravity. The internal space of the tube 62 is in the interior space on the distal end side (closed portion 62b side) while the internal space on the base end side (opening portion 62a side) communicates with the ink flow path 32 and is filled with ink. Contains gas (for example, air).

  A pressing mechanism 82 is disposed at an inner (inner peripheral side) position of the intermediate portion 62c supported by the intermediate support portion 81c of the frame body 81 in a state of being rotated once in the length direction. The pressing mechanism 82 rotates on a rotary plate 84 that can rotate around a drive shaft 83 as an axis that is the center of the arc of the support surface 81d, and on a distal end portion of a tongue piece portion 84a that protrudes radially outward of the rotary plate 84. And a pressing roller 85 as a pressing member provided as possible. An arc-shaped elongated hole 86 is formed at the tip of the tongue piece portion 66a, and the rotation shaft 87 of the pressing roller 85 is supported in the elongated hole 86 so as to be displaceable.

  That is, the long hole 86 is formed so that the distance from the drive shaft 83 is different at both ends in the longitudinal direction, and the rear side in the circular motion direction (counterclockwise direction) of the pressing roller 85 indicated by a hollow arrow in FIG. The proximal end of the tube 62 in the length direction is further away from the drive shaft 83.

  As shown in FIG. 8, when the pressing mechanism 82 is stopped, the rotary shaft 87 is positioned on the front side in the circular motion direction on the side close to the drive shaft 83 (the tip side in the length direction of the tube 62). Therefore, the pressing roller 85 is positioned at the non-blocking position P3 where the closed state of the internal space of the tube 62 is released.

  Further, when the pressing motor 71 is driven and the rotating plate 84 rotates together with the driving shaft 83, the rotating shaft 87 moves along the long hole 86 to the rear side away from the driving shaft 83, and the pressing roller 85 is connected to the tube 62. It moves to the closing position P4 (see FIG. 9) that closes the internal space.

When the rotating plate 84 stops rotating, the pressing roller 85 moves to the non-blocking position P3 by the restoring force of the elastic tube 62.
That is, in the present embodiment, while the pressing motor 71 is being driven, the pressing roller 85 is positioned at the closing position P4 and sandwiches and crushes the intermediate portion 62c of the tube 62 together with the intermediate support portion 81c. On the other hand, while the pressing motor 71 is stopped, the pressing roller 85 is located at the non-blocking position P3.

  Accordingly, a closed section (not shown) that is an area located while the pressing roller 85 is circularly moving in one direction and in which an annular section around the drive shaft 65 can close the inner space of the tube 62. It has become. Further, an annular section that is closer to the drive shaft 65 than the closed section and that has the drive shaft 65 as a center is a non-closed section (not shown) in which the closed state of the tube 62 is released.

  Next, the operation of the maintenance pump 80 configured as described above will be described below. As an initial state, it is assumed that the pressing roller 85 is located at a non-blocking position P3 in the non-blocking section as shown in FIG.

  Now, the controller 72 drives the pressing motor 71 to cause the pressing roller 67 to move circularly in the counterclockwise direction indicated by the white arrow in FIG. 8 around the drive shaft 65, and then drive the pressing motor 71. Stop.

  That is, the pressure roller 85 positioned at the non-blocking position P3 moves along the elongated hole 86 to the blocking position P4 in the blocking section, and the pressing point 62d moves in the counterclockwise direction. Increasing and ink flows from the ink flow path 32 (suction drive). On the other hand, since the volume in the gas chamber 70 decreases, the gas in the gas chamber 70 is compressed.

  For example, as shown in FIG. 9, when ink is sent into the gas chamber 70, the gas is compressed so as to be pushed against the liquid surface of the ink. When the driving of the pressing motor 71 is stopped and the pressing roller 85 moves to the non-blocking position P3, the ink moves to the opening 62a side by the pressure of the gas compressed in the gas chamber 70, and enters the ink flow path 32. Discharge (discharge drive).

According to the said 3rd Embodiment, in addition to the effect of (1)-(9) in 1st Embodiment and 2nd Embodiment, the following effects can be acquired further.
(10) Since the pressing roller 85 moves between the closed position P4 in the closed section and the non-closed position P3 in the non-closed section according to the driving and stopping of the press motor 71, the press roller 85 is moved a plurality of times. After the circular movement and the suction driving, the ejection driving can be performed. Therefore, since the ink exceeding the volume of the internal space in the intermediate portion 62c can be ejected, the maintenance pump 80 can be further downsized.

In addition, you may change the said embodiment as follows.
In the first and second embodiments, the pressure roller 67 may be positioned at the suction end position P2 during non-cleaning, and the pressure roller 67 may be rotated once around the drive shaft 65 from the suction end position P2 during cleaning. . That is, the maintenance pump 61 may be in a state where the volume of the ink chamber 69 is increased and the volume of the gas chamber 70 is reduced and the gas is compressed. The pressing roller 67 may be stopped in the non-clamping area A and rotated once from the non-clamping area A.

  In each of the above embodiments, the blocking portion 62b on the distal end side may be positioned below the opening 62a on the proximal end side in the gravity direction. That is, for example, the gas may be kept on the tip side (closed portion 62b side) depending on the thickness of the tube 62, the viscosity of the ink, and the surface tension.

  In each of the above embodiments, if the circular movement direction of the pressing rollers 67 and 85 is a circular movement in one direction, the circular direction is one direction approaching the proximal end side (opening 62a side) while the tube 62 is pressed. You may make it exercise. That is, when the pressing rollers 67 and 85 are positioned in the clamping region B and the tube 62 is crushed and circularly moves in one direction approaching the opening 62a on the proximal end side, the opening is more than the pressing point 62d in the tube 62. In the ink chamber 69 on the side of the part 62a, the volume decreases and the pressure in the ink chamber 69 increases, so that the ink (liquid) is discharged to the ink flow path 32 by the pressure. At that time, the volume of the gas chamber 70 on the distal end side (closed portion 62b side) of the pressing point 62d of the tube 62 is increased, so that the inside of the gas chamber 70 is decompressed. Then, when the pressure rollers 67 and 85 further move to the non-clamping region A by making a circular motion in one direction closer to the opening from that state, the ink is drawn into the decompressed gas chamber 70, thereby causing the proximal end. Ink is sucked from the side opening 62a. Therefore, ink can be sucked and discharged from one end of the tube 62 with a simple configuration.

  In each of the above embodiments, the ink chamber 69 may not be filled with ink. That is, for example, the ink level may be displaced in the internal space of the base end side portion where the opening 62a is provided.

  In each of the above embodiments, the blocking portion 62b on the distal end side of the tube 62 is not limited to the distal end of the tube 62, and can be arbitrarily set as long as it is on the distal end side with respect to the intermediate portion 62c. Further, the tube 62 may be closed by another member to form the closed portion 62b.

  In each of the above embodiments, a branch channel may be branched from the ink channel 32 at the transformation position PH, and the intermediate portion 62c of the tube 62 may be connected to the branch channel. In addition, the tube 62 may be connected to an intermediate portion 62c having elasticity with respect to a distal end portion formed of a rigid body. That is, the proximal end portion and the distal end portion need not have elasticity.

  In each of the above embodiments, the maintenance pump 61 may be connected to the reservoir 36, and the ink in the reservoir 36 may be sucked and discharged. That is, when the maintenance pump 61 is connected to the reservoir 36, the reservoir 36 functions as a liquid supply channel that supplies ink to the nozzles 30.

  In the second embodiment, in the state where the pressing roller 67 is positioned in the non-clamping area A, the ink may be filled up to the middle portion 62c. Further, the liquid level may be positioned at the tip side portion by increasing the volume of the inner space of the tip side portion than the volume of the inner space of the intermediate portion 62c. That is, even if ink enters the gas chamber 70, the ink chamber 69 is positioned on the lower side in the direction of gravity, so even when the gas is directly compressed by the ink, the discharge of the gas is suppressed and the ink is suppressed. Can be discharged.

  In the third embodiment, the pressing roller 67 may be circularly moved continuously for one or more rotations. Further, the flow rate of the ink discharged may be controlled according to the momentum of the pressing roller 67. That is, as the amount of motion of the pressing roller 67 increases, the amount of ink sucked from the ink flow path 32 increases and the amount of ink supplied to the leading end increases and the gas is compressed. It can discharge more vigorously.

  In the first and second embodiments, the cleaning process may be performed by circularly moving the pressing roller 67 around the drive shaft 65 a plurality of times. That is, when the circular movement is performed for a plurality of times, the pressure roller 67 alternately moves between the non-clamping area A and the clamping area B. Therefore, the suction drive and the discharge drive of the maintenance pumps 61 and 75 are executed alternately. Can do.

  In each of the above embodiments, the liquid ejecting apparatus is embodied in the ink jet printer 11, but a liquid ejecting apparatus that ejects or discharges liquid other than ink may be employed. The present invention can be used for various liquid ejecting apparatuses including a liquid ejecting head that ejects a minute amount of liquid droplets. 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. Further, representative examples of the liquid include ink and liquid crystal 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. As a specific example of the liquid ejecting apparatus, for example, a liquid containing a material such as an electrode material or a color material used for manufacturing a liquid crystal display, an EL (electroluminescence) display, a surface emitting display, a color filter, or the like in a dispersed or dissolved state. It may be a liquid ejecting apparatus for ejecting, a liquid ejecting apparatus for ejecting a bio-organic material used for biochip manufacturing, a liquid ejecting apparatus for ejecting a liquid as a sample used as a precision pipette, a textile printing apparatus, a microdispenser, or the like. In addition, transparent resin liquids such as UV curable resin to form liquid injection devices that pinpoint lubricant oil onto precision machines such as watches and cameras, and micro hemispherical lenses (optical lenses) used in optical communication elements. A liquid ejecting apparatus that ejects a liquid onto the substrate or a liquid ejecting apparatus that ejects an etching solution such as an acid or an alkali to etch the substrate may be employed. The present invention can be applied to any one of these liquid ejecting apparatuses.

  DESCRIPTION OF SYMBOLS 11 ... Printer (liquid ejecting apparatus), 12 ... Paper (target), 26-29 ... Recording head (liquid ejecting head), 31 ... Ink cartridge (liquid supply source), 32 ... Ink flow path (liquid supply flow path), 51 ... One-way valve, 61, 75, 80 ... Maintenance pump (tube pump), 62 ... Tube, 62a ... Opening part, 62b ... Closure part, 62c ... Intermediate part, 63, 76, 81 ... Frame (pump frame) , 63d, 76d, 81d ... support surface, 63e, 76e ... notch, 65, 83 ... drive shaft (axis), 67, 85 ... pressure roller (press member), 69 ... ink chamber (internal space), 70 ... Gas chamber (internal space), A ... non-clamping region (non-occlusion zone), B ... clamping region (occlusion zone), PH ... transforming position (second position), PT ... pressure-regulating position (first position).

Claims (5)

An opening that allows suction and discharge of liquid is provided on one end side in the length direction, and a blocking portion is provided on the other end side in the length direction, and at least an intermediate portion in the length direction has elasticity. When,
A pump frame having an arc-shaped support surface capable of supporting the intermediate portion of the tube along its length direction;
The axis that is the center of the arc of the support surface is centered between a closed section that crushes the intermediate portion and closes the internal space of the tube between the support surface and a non-closed section that is different from the closed section. As a circularly movable pressing member,
The pressing member is capable of circular motion in either one of a direction approaching the opening and a direction approaching the closing part in the length direction of the tube, and the pressing member is circular in the one direction. A tube pump, wherein the tube pump moves and moves in the closed section, and further moves in the one direction to move to the non-closed section. The pump frame has a cutout portion in which a part of the support surface is cut out in a circumferential direction around the axis.
The non-blocking section is a section where the pressing member is with respect to the notch,
The tube pump according to claim 1, wherein the closing section is a section that closes an internal space of the tube by the pressing member pressing the tube against the support surface. 3. The tube pump according to claim 1, wherein the blocking portion of the tube is positioned above the opening in the direction of gravity. 4. In the state in which the pressing member is filled with liquid in the internal space on the opening side in the length direction of the tube, rather than the position crushed by the pressing member in the intermediate portion of the tube, The tube pump according to any one of claims 1 to 3, wherein the circular motion of the pressing member is stopped in the closed section. A liquid ejecting head that ejects liquid onto a target;
A liquid supply channel for supplying the liquid from an upstream side which is a liquid supply source side toward a downstream side which is the liquid jet head side;
A one-way valve which is provided at a first position in the liquid supply flow path and allows passage of the liquid from the upstream side to the downstream side;
2. The liquid can be sucked and discharged from the second position by connecting the opening to a second position downstream of the first position in the liquid supply channel. A liquid ejecting apparatus comprising: the tube pump according to claim 4.

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