JP2010260248A - Tubing pump and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tubing pump and an image forming apparatus which can change a crush amount of a tube in an operating state. <P>SOLUTION: The tubing pump has a base which has a cylindrical inner surface and an entrance of the tube 100, and a pressure contact roller 101 which sends a fluid out of the tube by moving turning around a rotary shaft 102 set at the center of the cylindrical inner surface while crushing the tube. An interval between the pressure contact roller 101 and the rotary shaft 102 is variable. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a tubing pump that delivers liquid in a tube while crushing the tube, and an image forming apparatus including the tubing pump.

  As a type of printer, fax machine, copier, or a combination of these functions, a recording head comprising a liquid ejection head for ejecting liquid droplets of the recording liquid is provided, and the recording liquid is conveyed while conveying the recording medium (paper) It is known that a liquid discharge type image forming unit for forming an image by attaching ink droplets to a sheet is mounted.

  In such a liquid ejection type image forming apparatus, as a method of supplying a recording liquid to a recording head, an ink cartridge as an ink storage means for storing ink is detachably attached to a carriage on which the recording head is mounted. A system that supplies ink from the ink cartridge to the recording head and a small-capacity head tank (also referred to as a sub-tank) that is an ink storage unit that supplies ink to the recording head on the carriage are mounted on the carriage. There is a system in which a capacity ink cartridge (main tank) is replaceably mounted on the apparatus main body side, and ink is supplied to the head tank from the ink cartridge on the apparatus main body side.

  Among these, in the latter system, it is known to use a “tubing pump” as a means for supplying ink to the sub tank.

  The tubing pump as a means for replenishing and supplying ink to the sub tank has a function of feeding ink while crushing the tube, and a seal for preventing back flow of ink when the ink is not fed (stopped) (tube) The function of crushing without gaps is required.

  If there is an error in the amount of crushing of the tube due to the accuracy of stacking parts (accumulation of dimensional errors of the parts) or the accuracy of the outside diameter of the tube (especially because the tube is made of rubber, the tolerance is large) There was a problem that the time required for filling the sub-tank took longer than originally assumed due to an error in the amount of liquid to be fed, and there was a problem that the tube was crushed more than necessary and the life was shortened. .

Inventions related to the tubing pump are disclosed in Patent Documents 1 to 4.
Patent Document 1 discloses a mechanism in which the pressure roller does not crush the tube so that the pressure roller does not damage the tube when the tubing pump is not operated.

  Patent Document 2 relates to a method for fixing a roller-type tubing pump, and in order to facilitate the holding of the tube, a configuration in which the crushing dimension of the elastic tube is kept constant by mechanically contacting a movable tube fixing member. Is disclosed.

  Patent Document 3 discloses a mechanism in which a pressing member for detaching an elastic tube moves between the tubing pump guide surface and the tube pressing member for the purpose of easily detaching without fear of damage to the tube.

  Patent Document 4 discloses a driving means for stopping the rotor at a position disengaged from the stator for the purpose of facilitating the attachment / detachment of the tube.

  The invention described in Patent Document 1 can change the position of the pressure roller depending on whether or not the tubing pump is operating, but changes the amount of crushing of the tube when the tubing pump is operating. It is not possible.

  The invention described in Patent Document 2 keeps the tube crushing amount constant in order to prevent the tube from moving, and cannot change the tube crushing amount when the tubing pump is operating.

  The invention described in Patent Document 3 moves the tube pressing member so that the elastic tube can be attached and detached without damaging it, and changes the amount of tube crushing when the tubing pump is operating. It is not possible.

  The invention described in Patent Document 4 is to stop the rotor at a position deviated from the stator for the purpose of facilitating the detachment of the tube, and to reduce the amount of crushing of the tube when the tubing pump is operating. It cannot be changed.

  Thus, there has not been provided a tubing pump that can change the amount of crushing of the tube in the operating state.

  SUMMARY An advantage of some aspects of the invention is that it provides a tubing pump and an image forming apparatus capable of changing a crushing amount of a tube in an operating state.

  To achieve the above object, according to the present invention, as a first aspect, the substrate has a cylindrical inner surface and has an inlet / outlet of the tube, and a circular movement is performed while crushing the tube around a rotation axis provided at the center of the cylindrical inner surface. Accordingly, the present invention provides a tubing pump having at least one crushing member for delivering a fluid in the tube, wherein the distance between the crushing member and the rotating shaft is variable.

  In order to achieve the above object, according to a second aspect of the present invention, there is provided an image forming apparatus using the tubing pump according to the first aspect, wherein a tube is formed by a crushing member on a print head that ejects ink. It is an object of the present invention to provide an image forming apparatus that supplies ink delivered from a printer.

  ADVANTAGE OF THE INVENTION According to this invention, the tubing pump and image forming apparatus which can change the crushing amount of the tube in the operating state can be provided.

1 is an external perspective view of an ink jet recording apparatus as an image forming apparatus that preferably implements the present invention. It is a side view of the mechanism part of an inkjet recording device. It is a top view of the mechanism part of an inkjet recording device. It is a figure which shows the structure of a general tubing pump. It is a figure which shows the structure of the tubing pump which concerns on suitable embodiment of this invention. It is a figure which shows the cross-sectional structure of a tubing pump. It is a figure which shows the state which kept the pressure roller away from the rotating shaft. It is a figure which shows the state which brought the press roller close to the rotating shaft. It is a figure which shows the cross-sectional structure of the tubing pump in a parameter | index part.

FIG. 1 is an external perspective view of an ink jet recording apparatus as an image forming apparatus in which the present invention is suitably implemented as viewed from the front of the apparatus.
This ink jet recording apparatus is detachable from the apparatus main body 1, the paper feed tray 2 mounted on the apparatus main body 1 for loading paper, and the apparatus main body 1 for stocking paper on which images are recorded (formed). And a paper discharge tray 3 attached to the printer.
Further, at a position lower than the upper surface of the front surface on one end side of the front surface of the apparatus main body 1 (side of the paper supply / discharge tray section), a cartridge loading section 4 for loading ink cartridges is provided in front of the apparatus main body 1. It is provided to protrude. An operation / display unit 5 is provided on the upper surface of the cartridge loading unit 4 to provide operation buttons and a display.

  The cartridge loading unit 4 includes a plurality of recording liquids (inks) that are different color materials, for example, black (K) ink, cyan (C) ink, magenta (M) ink, and yellow (Y) ink. Ink cartridges 10k, 10c, 10m, and 10y that are liquid cartridges (indicated as “ink cartridge 10” when colors are not distinguished) can be inserted and loaded from the front side of the apparatus main body 1 toward the rear side. It has become. A cover (cartridge cover) 6 that is opened when the ink cartridge 10 is attached or detached is provided on the front side of the cartridge loading unit 4 so as to be openable and closable.

Next, the mechanism part of the ink jet recording apparatus will be described. FIG. 2 is a side view schematically showing an outline of a mechanism portion of the ink jet recording apparatus, and FIG. 3 is a plan view.
The carriage 33 is slidably held in the main scanning direction by main and slave guide rods 31 and 32 which are guide members horizontally mounted on the left and right side plates 21A and 21B of the apparatus main body 1, and a timing belt is supported by a main scanning motor (not shown). 3 is moved and scanned in the direction indicated by the arrow in FIG. 3 (carriage main scanning direction). The carriage 33 has recording heads 34a and 34b composed of liquid ejection heads for ejecting ink droplets of each color of yellow (Y), cyan (C), magenta (M), and black (K). Nozzle array consisting of a plurality of nozzles is arranged in the sub-scanning direction orthogonal to the main scanning direction, and is mounted with the ink droplet ejection direction facing downward. Each of the recording heads 34 has two nozzle rows. One nozzle row of the recording head 34a has black (K) droplets, the other nozzle row has cyan (C) droplets, and the recording head 34b has one nozzle row. One nozzle row discharges magenta (M) droplets, and the other nozzle row discharges yellow (Y) droplets.

  As an inkjet head constituting the recording head 34, a piezoelectric actuator such as a piezoelectric element, a thermal actuator that uses a phase change caused by film boiling of a liquid using an electrothermal transducer such as a heating resistor, and a metal phase change caused by a temperature change. It is possible to use a shape memory alloy actuator to be used, an electrostatic actuator using an electrostatic force, or the like provided as pressure generating means for generating a pressure for discharging a droplet.

  The carriage 33 is equipped with head tanks 35a and 35b (indicated as “head tank 35” when not distinguished) for supplying ink of each color corresponding to the nozzle row of the recording head 34. . The head tank 35 is supplementarily supplied with ink of each color from the ink cartridge 10 of each color mounted in the cartridge loading unit 4 via the supply tube 36 of each color. The cartridge loading unit 4 is provided with a supply pump unit 24 having a tubing pump for feeding ink in the ink cartridge 10.

  On the other hand, as a paper feeding unit for feeding the papers 42 stacked on the paper stacking unit (pressure plate) 41 of the paper feed tray 2, a half-moon roller (paper feeding) that separates and conveys the papers 42 from the paper stacking unit 41 one by one. Roller) 43 and a separation pad 44 made of a material having a large friction coefficient and facing the sheet feeding roller 43, and the separation pad 44 is urged toward the sheet feeding roller 43 side.

  In order to feed the paper 42 fed from the paper feeding unit to the lower side of the recording head 34, the paper has a guide member 45 for guiding the paper 42, a counter roller 46, a transport guide member 47, and a tip pressure roller 49. In addition to a pressing member 48, a conveyance belt 51 is provided as conveyance means for electrostatically attracting the fed paper 42 and conveying it at a position facing the recording head 34.

  The conveyance belt 51 is an endless belt, and is installed between the conveyance roller 52 and the tension roller 53 so as to circulate in the belt conveyance direction (sub-scanning direction).

A charging roller 56 is provided as a charging unit for charging the surface of the conveyance belt 51. The charging roller 56 is disposed so as to come into contact with the surface layer of the transport belt 51 and to rotate following the rotation of the transport belt 51.
The conveyance belt 51 rotates in the belt conveyance direction of FIG. 3 when the conveyance roller 52 is rotationally driven via a timing belt by a sub-scanning motor (not shown).

  Further, as a paper discharge unit for discharging the paper 42 recorded by the recording head 34, a separation claw 61 for separating the paper 42 from the conveying belt 51, a paper discharge roller 62, and a paper discharge roller 63 are provided. In addition, a paper discharge tray 3 is provided below the paper discharge roller 62.

  A duplex unit 71 is detachably mounted on the back surface of the apparatus body 1. The duplex unit 71 takes in the paper 42 returned by the reverse rotation of the transport belt 51, reverses it, and feeds it again between the counter roller 46 and the transport belt 51. The upper surface of the duplex unit 71 is a manual feed tray 72.

  Further, a maintenance / recovery mechanism 81 that is a head maintenance / recovery device including a recovery means for maintaining and recovering the state of the nozzles of the recording head 34 is disposed in a non-printing area on one side of the carriage 33 in the scanning direction. Yes. The maintenance / recovery mechanism 81 includes cap members (hereinafter referred to as “caps”) 82a and 82b (hereinafter referred to as “caps 82” when not distinguished) for capping each nozzle surface of the recording head 34. , A wiper blade 83 which is a blade member for wiping the nozzle surface, and an empty discharge receiver 84 for receiving droplets when performing empty discharge for discharging droplets that do not contribute to recording in order to discharge the thickened recording liquid. Etc. A waste liquid tank 90 for storing waste liquid generated by the head maintenance and recovery motion is replaceably attached to the apparatus main body 1.

  In addition, in the non-printing area on the other side of the carriage 33 in the scanning direction, the liquid that receives liquid droplets when performing idle ejection for ejecting liquid droplets that do not contribute to recording in order to discharge the recording liquid thickened during recording or the like. An ink recovery unit (empty discharge receiver) 88 that is a recovery container is disposed, and the ink recovery unit 88 includes an opening 89 along the nozzle row direction of the recording head 34.

  In the image forming apparatus configured as described above, the sheets 42 are separated and fed one by one from the sheet feeding tray 2, and the sheets 42 fed substantially vertically upward are guided by the guide 45, and the conveying belt 51 and the counter roller 46, and the leading end is guided by the conveying guide member 47 and pressed against the conveying belt 51 by the tip pressing roller 49, and the conveying direction is changed by approximately 90 degrees.

  At this time, a positive output and a negative output are alternately repeated with respect to the charging roller 56, that is, an alternating voltage is applied, and a charging voltage pattern in which the conveying belt 51 alternates, that is, in the sub-scanning direction that is the circumferential direction. Plus and minus are alternately charged in a band shape with a predetermined width.

  When the paper 42 is fed onto the conveyance belt 51 that is alternately charged with plus and minus, the paper 42 is attracted to the conveyance belt 51, and the paper 42 is conveyed in the sub scanning direction by the circular movement of the conveyance belt 51.

  Therefore, by driving the recording head 34 according to the image signal while moving the carriage 33, the ink droplets are ejected onto the stopped paper 42 to record one line, and the paper 42 is conveyed by a predetermined amount. To record the next line.

Upon receiving a recording end signal or a signal that the trailing edge of the paper 42 has reached the recording area, the recording operation is finished and the paper 42 is discharged onto the paper discharge tray 3.
During printing (recording) standby, the carriage 33 is moved to the maintenance / recovery mechanism 81 side, and the recording head 34 is capped by the cap 82 to keep the nozzle in a wet state, thereby preventing ejection failure due to ink drying. To do. Further, the recording liquid is sucked from the nozzle by a suction pump (not shown) while the recording head 34 is capped by the cap 82 (referred to as “nozzle suction” or “head suction”), and the thickened recording liquid and bubbles are discharged. Perform recovery action.
Further, before the start of recording or during recording, an idle ejection operation is performed in which ink (liquid droplets that become waste liquid) unrelated to recording is ejected toward the ink recovery unit 88 or the like. As a result, the stable ejection performance of the recording head 34 is maintained.

  Next, the supply pump unit 24 will be described.

  As shown in FIG. 4, a general tubing pump has an outer diameter of a tube 200 disposed in a substantially annular shape on a cylindrical inner surface of a case (not shown) having a predetermined inner diameter. The tube 200 is crushed by a certain amount by the pressure roller 201 provided on the center side of the case, and the pressure roller 201 rotates in the clockwise direction in FIG. Sent in the direction. At this time, the amount of liquid fed per unit time changes according to the amount of crushing of the tube 200. Factors causing fluctuations in the crushing amount of the tube 200 include variations due to component tolerances of each component (shaft, pressure roller rotation center inner diameter, pressure roller mounting portion, pressure roller inner / outer diameter, tube inner / outer diameter, case inner diameter, etc.) The deterioration of parts over time is considered.

  FIG. 5 shows the configuration of the tubing pump provided in the supply pump unit 24. FIG. 6 shows a cross-sectional configuration of the tubing pump. A cam 103 is provided inside the pressure roller 101. When the cam 103 rotates in the direction of arrow C in FIG. 5, the pressure roller 101 moves in a direction away from the shaft 102 along the elongated hole 104 a provided in the lid 104. Conversely, when the cam 103 is rotated in the direction of arrow D in FIG. 5, the pressure roller 101 moves in a direction approaching the shaft 102 along the elongated hole 104 a provided in the lid 104. When the crushing amount of the tube 100 does not become the assumed amount due to the component stacking variation, the crushing amount of the tube 100 can be assumed as the assumed amount by adjusting the position of the pressure roller 101. Thereby, the optimal liquid feeding amount is securable. Even when the tube 100 is crushed more than necessary, the amount of crushing of the tube 100 can be assumed by adjusting the position of the pressure roller 101. Thereby, it can prevent that the lifetime of the tube 100 becomes short.

  An index 105 is provided at a position where the cam stopper 103a that rotates integrally with the cam 103 is fixed, so that the amount of crushing of the tube 100 can be easily visually confirmed. 7 shows a state in which the pressure roller 101 is moved away from the rotation shaft 102 (the crushing amount of the tube 100 is large), and FIG. 8 shows a state in which the pressure roller 101 is brought close to the rotation shaft 102 (the crushing amount of the tube is small). Show.

  FIG. 9 shows a cross-sectional configuration of the tubing pump at the index 105 portion. The lid 104 is provided with a concave portion at a position corresponding to each index so that a stopper projection 103b formed on the cam stopper 103a can be fitted. By forming the cam stopper 103a to be elastically deformable, the stopper protrusion 103b can be fitted into an arbitrary recess of the lid 104 as the cam 103 rotates, and the cam stopper 103a can be fixed. That is, the amount of crushing of the tube 100 can be easily changed simply by changing the recess into which the stopper projection 103b is fitted.

In the image forming apparatus according to the present embodiment, when a malfunction due to ink feeding failure occurs in the tubing pump provided in the supply pump unit 24, the difference from the specified time is measured by measuring the time from the start of ink filling to the detection of the sub tank full. And a variable amount of the cam 103 (the position of the index 105 pointed to by the cam stopper 103a) corresponding thereto is displayed on the display unit of the apparatus main body 1.
Since the tube crushing amount of the tubing pump provided in the supply pump unit 24 is variable stepwise, the variable amount of the cam 103 is displayed so that the cam 103 is positioned at a position corresponding to the displayed variable amount at the time of repair. Appropriate liquid feeding performance can be recovered simply by disposing.

  In addition to the case where a failure occurs, the present invention can also be applied as a confirmation of the initial performance of the tubing pump (for example, a liquid feeding confirmation jig device).

  The supply pump unit including the tubing pump according to the above configuration can keep the tube crushing amount constant. Thereby, liquid feeding performance can be stabilized.

The said embodiment is an example of suitable implementation of this invention, and this invention is not limited to this.
For example, in the above-described embodiment, the configuration in which the interval between the pressure roller 101 and the shaft 102 can be changed stepwise is taken as an example, but it is needless to say that the configuration can be changed continuously.
Moreover, in the said embodiment, although the structure provided with the two pressure rollers 101 was made into the example, the number of the pressure rollers 101 may be three or more, and may be one.
As described above, the present invention can be variously modified.

DESCRIPTION OF SYMBOLS 1 Apparatus main body 2 Paper feed tray 3 Paper discharge tray 4 Cartridge loading part 5 Operation / display part 6 Cover (cartridge cover)
DESCRIPTION OF SYMBOLS 10 Ink cartridge 21 Side plate 24 Supply pump unit 31, 32 Guide rod 33 Carriage 34 Recording head 35 Head tank 36 Supply tube 41 Paper loading part 42 Paper 43 Half moon roller (paper supply roller)
44 Separating Pad 45 Guide Member 46 Counter Roller 47 Conveying Guide Member 48 Holding Member 49 Tip Pressure Roller 51 Conveying Belt 52 Conveying Roller 53 Tension Roller 56 Charging Roller 61 Separation Claw 62 Discharging Roller 63 Discharging Roller 71 Duplex Unit 72 Manual Tray 81 Maintenance and recovery mechanism 82 Cap 83 Wiper blade 84 Empty discharge receiver 88 Ink collection unit 89 Opening 90 Waste liquid tank 100 Tube 101 Pressure roller 102 Rotating shaft 103 Cam 103a Cam stopper 103b Stopper projection 104 Lid 104a Slot 105 105 Index

JP-A-6-143613 JP 2003-254260 A JP-A-5-44655 JP-A-6-327763

Claims (7)

A substrate having a cylindrical inner surface and having a tube inlet and outlet;
Having at least one crushing member for delivering fluid in the tube by moving around the tube while crushing the tube around a rotation axis provided at the center of the cylindrical inner surface;
A tubing pump characterized in that a distance between the crushing member and the rotating shaft is variable.   The crushing member is supported so as to be slidable in the radial direction of the orbit, and the interval between the crushing member and the rotating shaft is changed in accordance with the amount of contact of the cam contacting from the rotating shaft side. The tubing pump according to claim 1.   The tubing pump according to claim 2, wherein the crushing member is supported by a long hole formed in a member that rotates around the rotation shaft as the circular member moves.   The tubing pump according to any one of claims 1 to 3, wherein an interval between the crushing member and the rotation shaft is variable stepwise.   5. The tubing pump according to claim 4, further comprising means for displaying which stage the interval between the crushing member and the rotating shaft is set to. An image forming apparatus using the tubing pump according to any one of claims 1 to 5,
An image forming apparatus, wherein the ink sent from the tube is supplied to the print head for discharging ink by the crushing member. A difference detecting means for detecting a difference between a liquid feeding amount of the ink sent to the print head by the tubing pump and a predetermined liquid feeding amount;
Based on the detection result of the difference detection means, the crushing member and the rotary shaft that are necessary to set the liquid feeding amount of the ink sent to the print head by the tubing pump to the predetermined liquid feeding amount. 7. The image forming apparatus according to claim 6, further comprising means for displaying an interval adjustment amount.

Images