JP5427537B2 - Inkjet recording device - Google Patents

Description

  The present invention relates to a structure of a circulation unit in which an ink and a flow path constituting a solvent circulation path and a fluid control component are integrally arranged on a manifold plate of an ink jet recording apparatus.

  Inkjet recording apparatuses are installed on a production line for printing objects, but installation space is often limited, and downsizing of the apparatus has been demanded.

  Many fluid control components such as pumps and electromagnetic valves for controlling the flow of liquid such as ink and solvent are used in the ink jet recording apparatus. Conventionally, each fluid control device has been connected by a piping tube. Thereafter, it has become common to construct a circulation unit by mounting a fluid control component on a manifold plate in which a flow path connecting the fluid control devices is formed.

  A circulation unit in which only a plurality of electromagnetic valves are mounted on a manifold plate and a circulation unit in which not only electromagnetic valves but also pumps, pressure reducing valves, filters, containers, and the like are mounted are known (for example, see Patent Document 1).

  Thereafter, by providing a pressure chamber for converting ink pressure into solvent pressure, the number of solvent pumps has been reduced, and further downsizing of the apparatus has been promoted (see, for example, Patent Document 2).

JP 2001-146020 A Japanese Patent Application No. 2008-238182

  Although we have tried to reduce the piping tube installation space and reduce the size of the device by configuring the circulation unit by mounting fluid control parts on the manifold plate that forms the flow path connecting each fluid control device inside, In order to further reduce the size of the apparatus, it has been necessary to reduce the number of fluid control components mounted on the circulation unit.

  Therefore, it became possible to reduce the number of solvent pumps by providing a pressure chamber that converts ink pressure into solvent pressure. However, it was necessary to secure installation space for the added pressure chamber, saving space. Is not tied to. If the pressure chamber is installed outside the circulation unit and connected by a piping tube, the installation space for the pressure chamber and the piping tube is required and space saving cannot be achieved.

  Even if the pressure chamber is installed directly on the circulation unit without piping tubes, the pressure chamber has four inlets / outlets on the primary and secondary sides of the ink chamber, and on the primary and secondary sides of the solvent chamber. In addition, the addition of four seals at the connection with the manifold plate not only increases the potential for liquid leakage compared to the conventional case, but also adds parts for fixing, which complicates the structure. Furthermore, since the installation space for the pressure chamber itself is additionally required on the manifold plate, effective space saving cannot be achieved.

  An object of the present invention is to provide a circulation unit and an ink jet recording apparatus which are significantly reduced in size compared to the conventional one by reducing the solvent pump by using a pressure chamber and arranging a pressure chamber with a small installation space. It is in.

In order to achieve the above object, for example, an ink container that holds ink, a pressurizing unit that pressurizes the ink in the ink container and ejects it from a nozzle, a gutter that supplements ink particles that are not used for printing, An ink jet recording apparatus comprising: a collecting unit that collects ink captured by a gutter in the ink container; and a solvent container that holds a solvent used for cleaning the nozzle and diluting the ink. Ink circulation unit with pump, solenoid valve, piping connection port , ink chamber mounted on manifold plate with passage formed, and solenoid valve, piping connection port, solvent chamber on manifold plate with flow path for solvent inside the anda solvent circulation unit mounted, said solvent circulation unit and the ink circulation unit, before the ink chamber of the ink circulation unit And a solvent chamber in a solvent circulation unit through to face the film-like elastic body forms a pressure chamber for supplying the solvent to the said ink container nozzle by closely fixed, constitutes a circulation unit integral It is characterized by.

  By adopting the configuration according to the present invention, it is possible to add a pressure chamber without increasing the installation space on the circulation unit, and to provide a further miniaturized ink jet recording apparatus by reducing the space space where the solvent pump has been conventionally installed. can do.

It is a perspective view of the main body and print head of an inkjet recording device. It is a perspective view which shows the use condition of an inkjet recording device. 1 is a path configuration diagram of an ink jet recording apparatus showing an embodiment of the present invention. It is a perspective view which shows the basic operation | movement of an inkjet recording device. It is a front view of the filter structure of the inkjet recording device which shows one Example of this invention. 1 is a perspective view of a circulation unit structure of an ink jet recording apparatus showing an embodiment of the present invention. It is sectional drawing of the circulation unit structure of the inkjet recording device which shows one Example of this invention. 1 is a perspective view of a manifold plate constituting a circulation unit of an ink jet recording apparatus showing an embodiment of the present invention. 1 is an exploded perspective view of a manifold plate constituting a circulation unit of an ink jet recording apparatus showing an embodiment of the present invention. 1 is an exploded view of a pressure chamber diaphragm portion of an ink jet recording apparatus showing an embodiment of the present invention.

  Hereinafter, the present embodiment will be described with reference to the illustrated example. The present invention is not limited to the illustrated example.

  FIG. 1 is an overall view showing an ink jet recording apparatus 100 according to this embodiment of the present invention. The ink jet recording apparatus 100 includes a main body 1 provided with an operation display unit 3 and a print head 2 outside. The main body 1 and the print head 2 are connected by a conduit 4.

  FIG. 2 shows an example of an actual use state of the ink jet recording apparatus 100. The ink jet recording apparatus 100 is installed on a production line in a factory where food, beverages, and the like are produced, for example, the main body 1 is installed at a position where the user can operate, and the print head 2 is on a production line such as a belt conveyor 5. Is placed at a position where it can be brought close to the printing object 6 to be conveyed.

  In order to print on the production line such as the belt conveyor 5 with the same width regardless of the conveyance speed, the encoder 7 that outputs a signal corresponding to the conveyance speed to the inkjet recording apparatus 100 or the print object 6 is detected and the inkjet is performed. A print sensor 8 that outputs a signal for instructing printing to the recording apparatus 100 is installed, and each is connected to a control unit 200 (not shown) in the main body 1.

  While the control unit 200 controls the charge amount and timing of the ink particles 10 ejected from the nozzles 9 in accordance with signals from the encoder 7 and the print sensor 8, while the print target 6 passes near the print head 2. Printing is performed by adhering the charged and deflected ink particles 10 to the printing object 6.

  FIG. 3 is a diagram illustrating an overall path configuration of the inkjet recording apparatus 100. The main body 1 is provided with a main ink container 20 for holding circulating ink, and the main ink container 20 has an appropriate amount for holding the liquid in the main ink container 20 therein. A liquid level sensor 21 is provided for detecting whether or not a reference liquid level has been reached. A path 101 is connected to the main ink container 20 and is opened and closed by an electromagnetic valve 22. Normally, the supply pump 23 sucks ink through the path 101, but when the ink viscosity measurement is performed by providing the bypass path 102 provided with the viscosity measuring device 24 which is a drop type viscometer for measuring the viscosity of the ink. Only the supply pump 23 sucks ink from the path 102 and refreshes the ink to be measured.

  The viscosity measuring device 24 is connected to an electromagnetic valve 25 that opens and closes a path via a path 102, and the secondary side of the electromagnetic valve 25 is connected to a pump 23 that is used for suction and pressure feeding of ink via a path 101. Has been. The pump 23 is connected to the ink chamber 27 for pressurizing the solvent by the ink pressure via the diaphragm 26 via the path 103. When the pressure of the ink pressurized by the supply pump 23 pressurizes the solvent in the solvent chamber 62 via the diaphragm 26, the solvent can be supplied to the print head 2. The ink chamber 27 is connected via a path 104 to an ink filter 28 that removes foreign matters mixed in the ink.

  The ink filter 28 is connected to a pressure reducing valve 29 that adjusts to an appropriate pressure for printing the ink pumped from the pump 23 via the path 105, and the pressure reducing valve 29 is an ink supply path 106 passing through the inside of the conduit 4. Is connected to the primary side of a three-port solenoid valve 30 provided in the print head 2. The secondary side of the three-port solenoid valve 30 is connected via a path 107 to a nozzle 9 provided with a discharge port for discharging ink. The 3-port solenoid valve 30 has 2 ports on the primary side and 1 port on the secondary side, and is configured to selectively switch the primary side port communicating with the secondary side port. The solvent supply path 121 is connected to the normally open port to the normally closed port.

  A suction passage 112 that branches off before the nozzle 9 is connected to the secondary side path 107 of the three-port solenoid valve 30. The suction flow path 112 passes through the conduit 4 and is connected to the electromagnetic valve 41 via a pressure gauge 40 that measures the pressure of the ink. The secondary side of the solenoid valve 41 is connected to the recovery pump 50, and performs a suction operation when the ink is filled or the ejection port of the nozzle 9 is clogged using the suction path 112.

  In the ink discharge direction of the nozzle 9, a charging electrode 11 that charges the particle with an amount of charge corresponding to character information printed on the ink particle 10 discharged from the nozzle 9 is disposed. In the flying direction of the ink particles 10 charged by the charging electrode 11, a deflection electrode 12 that generates an electric field that deflects the charged ink particles 10 is disposed.

  On the ink flying direction side of the deflection electrode 12, a gutter 14 for capturing ink particles 10 that fly linearly without being charged and deflected not used for printing is disposed.

  The gutter 14 is connected to a recovery filter 51 that removes foreign matters mixed in the ink disposed in the main body 1 via a recovery path 108 that passes through the conduit 4, and the recovery filter 51 is connected to the path 109. Is connected to a solenoid valve 15 that opens and closes a recovery path via a suction path, and is connected to a recovery pump 50 that sucks ink particles 10 captured by the gutter 14 via a path 110. The recovery pump 50 sends the ink sucked through the path 111 to the main ink container 20.

  Further, the main body 1 is provided with a solvent container 60 that holds a solvent for cleaning the nozzle 9 and adjusting the viscosity of the ink when stopped, and the solvent container 60 is a solvent filter that removes foreign matter in the solvent path. A solvent chamber 63 that sucks and pumps the solvent is connected via a check valve 62 that prevents backflow of the solvent through a path 120 in which 61 is disposed. The solvent chamber 63 is connected to the solenoid valve 64 via a path 121, and the secondary side of the solenoid valve 64 is connected to the primary port of the three-port solenoid valve via a solvent supply path 122 passing through the conduit 4. . The path 120 through which the solvent is sucked from the solvent container 60 is connected to the electromagnetic valve 65 via the path 123, and the electromagnetic valve 65 is connected to the recovery pump 50 via the path 124.

  Further, the main body 1 is provided with an auxiliary ink container 80 that holds ink for replenishment. The auxiliary ink container 80 is connected to an electromagnetic valve 81 that opens and closes a path via a path 130. The electromagnetic valve 81 is connected to the supply pump 23 via a path 131.

  Here, the operation principle of the inkjet recording apparatus 100 will be described. The ink jet recording apparatus 100 shown in FIG. 4 is the same as the ink jet recording apparatus 100 shown in FIG. 1, but only parts necessary for explaining the operation principle will be described.

  As shown in FIG. 4, the ink in the ink container 20 is sucked and pressurized by the pump 23 to become the ink column 17 and is ejected from the nozzle 9. The nozzle 9 is provided with an electrostrictive element 18, and the ink column 17 ejected from the nozzle 9 is made into particles by applying vibration to the ink at a predetermined frequency. The number of ink particles 10 thus generated is determined by the frequency of the excitation voltage applied to the electrostrictive element 18 and is the same as the frequency. The ink particles 10 are given a charge by applying a voltage having a magnitude corresponding to the print information at the charging electrode 11.

  The ink particles 10 charged by the charging electrode 11 are deflected by receiving a force proportional to the charge amount while flying in the electric field between the deflection electrodes 12, flying toward the printing object 6 and landing. To do. At that time, the landing position of the ink particle 10 in the deflection direction changes according to the charge amount, and the production line 6 moves the print target 6 in the direction orthogonal to the deflection direction, so that the ink particle 10 also moves in the direction orthogonal to the deflection direction. Particles can be landed, and a character is constituted by a plurality of landed particles.

  Ink particles 10 that are not used for printing fly linearly between the deflection electrodes 12 and are collected by the main ink container 20 via the collection path 108 after being captured by the gutter 14. .

  Next, FIG. 5 shows a functional block diagram of the inkjet recording apparatus 100. The ink jet recording apparatus 100 includes a control unit 200 including, for example, an MPU. The control unit 200 includes an operation display unit 3, a nozzle 9, a charging electrode 11, a deflection electrode 12, an encoder 7, via a bus line 201. The print sensor 8, the viscosity measuring device 15, the solenoid valves 22, 25, 41, 63, 64, 81, the pumps 23, 50, the three-port solenoid valve 30, the liquid level sensor 38, the pressure gauge 40, the recording unit 202, etc. It comes to control.

  The recording unit 202 stores a program for controlling the ink jet recording apparatus 100, and the control unit 200 controls each part of the ink jet recording apparatus 100 based on the program.

  Below, the effect | action of the invention concerning a present Example is demonstrated using FIG. 3, FIG. 6 and 7 show the overall structure of the circulation unit 300 of the ink jet recording apparatus. The circulation unit 300 includes an ink circulation unit 301 that controls ink and a solvent circulation unit 302 that controls a solvent. The ink circulation unit 301 and the solvent circulation unit 302 are closely fixed to constitute an integrated circulation unit 300. ing. The ink circulation unit 301 includes a supply pump 23 that supplies ink to the nozzle 9 and a recovery pump 50 that recovers ink from the gutter 14 on one surface of the first manifold plate 303 in which a flow path through which ink flows is formed. And a drive system having a motor 310 and a cam 311 for driving the supply pump 23 and the recovery pump 50 are installed. The ink chamber 27 of the pressure chamber 320 is provided on the surface of the first manifold plate 303 facing the pump installation surface.

  In addition, solenoid valves 15, 22, 25, 41, 70, 81 and a viscometer 24 are installed on the surface of the first manifold plate 303 which is perpendicular to and upright of the pump installation surface and the pressure chamber 320 installation surface. The pressure sensor 40 is installed on the upper surface of the first manifold plate 303 on which 330 is installed.

  As shown in FIG. 3, the ink sucked from the ink main container 20 through the pipe tube is connected to the pipe joint 330 disposed on the upper surface of the ink circulation unit 301 and sucked into the ink circulation unit 330. The ink that has entered the ink circulation unit 301 is sucked by the supply pump 25 through the path 131 via the electromagnetic valve 22 disposed on the path 101 formed in the first manifold plate 303. On the other hand, a viscometer 24 for measuring the ink viscosity is disposed on the path 102 branched from the path 101, and the secondary side of the viscometer 24 joins the path 131 and is connected to the primary side of the supply pump 25.

  The secondary side of the supply pump 25 is connected to the primary side of the pressure chamber 320 ink chamber 27 via a path 132 that traverses the first manifold plate 303. The secondary side of the ink chamber 27 of the pressure chamber 320 is connected to the piping tube by the piping joint 330 disposed on the upper surface of the ink circulation unit 301 via the path 104 and sent to the ink filter 28.

  As shown in FIG. 3, the ink collected from the gutter 14 passes through the piping tube and is sucked into the ink circulation unit 301 through the piping joint 330 arranged on the upper surface of the ink circulation unit 301 shown in FIGS. Is done. The ink that has entered the ink circulation unit 301 passes through the path 109 in the first manifold plate 303 and is connected to the primary side of the electromagnetic valve 15 that opens and closes the recovery flow path. The secondary side of the electromagnetic valve 15 is sucked by the recovery pump 50 via a path 110 that traverses the first manifold plate 303. The ink ejected from the recovery pump 50 is connected to the pipe tube by the pipe 111 and the pipe joint 330 disposed on the upper surface of the ink circulation unit 301 and is sent to the ink main container 20.

  As shown in FIG. 3, the path 132 branches to a path 133 having an electromagnetic valve 70 on the path for releasing the pressure of the supply path. The secondary side of the solenoid valve 70 is connected to the path 110, and when the solenoid valve 70 is opened, the pressure of the entire supply path is released to the path 110.

  On the other hand, as shown in FIG. 7, the solvent circulation unit 302 is provided with the solvent chamber 63 of the pressure chamber 320 on one surface of the second manifold plate 304 in which a flow path through which the solvent flows is formed. . Further, on the surface of the second manifold plate 304 that is perpendicular to the pressure chamber 320 installation surface and upright, the solenoid valve 64 that performs control to send the solvent for cleaning the nozzle 9 to the nozzle 9 side, and the ink in the ink main container 20 are supplied. An electromagnetic valve 65 for controlling supply of the solvent to the ink main container 20 for dilution is provided.

  As shown in FIG. 3, the solvent passes through the piping tube from the solvent container 60 and is sucked into the solvent circulating unit 302 through the piping joint 330 disposed on the upper surface of the solvent circulating unit 302 shown in FIG. 7. The ink that has entered the solvent circulation unit 302 passes through the path 120 in the second manifold plate 304 and is connected to the primary side of the pressure chamber 320 and the solvent chamber 63 via the check valve 62 for preventing backflow of the solvent. The secondary side of the pressure chamber 320 solvent chamber 63 passes through the path 121 and is connected to the primary side of the solenoid valve 64, and the secondary side of the solenoid valve 64 passes through the path 122 and the pipe joint 330 disposed on the upper surface of the circulation unit 300. Is connected to the piping tube and sent to the print head 2 direction.

  A path 123 branched from the path 120 is connected to the primary side of the electromagnetic valve 65, and the secondary side of the electromagnetic valve 65 is connected to the path 110 in the ink circulation unit 301 when fixed integrally with the ink circulation unit 301. Connected. When the electromagnetic valve 65 is opened, the solvent is sucked by the recovery pump 50 via the path 110 and replenished to the ink main container 20. The end of the path 110 of the ink circulation unit 301 and the secondary side flow path of the electromagnetic valve 65 of the solvent circulation unit 302 are connected via an O-ring 400.

  The ink chamber 27 and the solvent chamber 63 of the pressure chamber 320 are provided with a flange portion 340 integrally with the first manifold plate 303 and the second manifold plate 304, and the first manifold plate 303 and the second manifold plate are provided on the outer periphery of the flange portion 340. Four fixing portions 342 for fixing 304 with screws 341 are provided at the entire circumference.

  As shown in FIG. 8, an ink chamber 27 having a primary side path 132 and a secondary side path 104 is provided inside the flange 340 of the first manifold 303, and inside the flange 340 of the second manifold 304, A solvent chamber 63 having a primary side path 120 and a secondary side path 121 of the solvent chamber 63 shown in FIG.

  As shown in FIGS. 7 and 10, the ink chamber 27 formed in the ink circulation unit 301 and the solvent chamber 63 formed in the solvent circulation unit 302 face each other and are in close contact with each other via the rubber diaphragm 26. Fix it. The diaphragm 26 has a through hole 350 in the center, and a center disk 352 having a projecting portion 351 passing through the through hole 350 and a spring 354 having a hole 353 to be fitted with the projecting portion 351 are screwed with a screw 355 sandwiching the diaphragm 26. Fix it.

  With this structure, the spring plate 354 and the center disk 352 become rigid and move in the space between the ink chamber 27 and the solvent chamber 63. On the other hand, the outer peripheral side of the center disk 352 and the spring plate 354 becomes a rubber diaphragm 26, and this portion becomes a flexible film, and the rigid body portion fixed by the center disk 352 and the spring plate 354 can be displaced.

  As shown in FIG. 10, a bead portion 360 for preventing liquid leakage from the ink chamber 27 and the solvent chamber 63 to the outside of the circulation unit 300 is provided on the outer periphery of the diaphragm 26. As shown in FIG. 9, the first manifold plate 303 and the second manifold plate 304 are provided with groove portions 362 for arranging the bead portions 360 of the diaphragm 26 on the entire circumference. This portion has a structure for the purpose of enhancing the pressure resistance and preventing the diaphragm 26 from being pulled inward.

  As shown in FIGS. 7 and 9, a compression spring 365 is disposed on the solvent chamber 63 side so as to displace the rigid body portion fixed by the center disk 352 and the spring plate 354 toward the ink chamber 27 side. One end of the compression spring 365 is located in a stepped portion 367 provided in the vicinity of the check valve 62 installation portion of the second manifold 304, and the other end is in contact with the spring 354.

Here, if P1 = ink chamber pressure × diaphragm pressure receiving area and P2 = solvent chamber pressure × diaphragm pressure receiving area + compression spring load, the diaphragm 26 tends to reduce the volume on the solvent chamber 63 side when P1> P2. Displaced, the pressure chamber 320 can push the solvent to the secondary side. On the other hand, when P1 <P2, the diaphragm 26 is displaced in the direction of increasing the volume on the solvent chamber 63 side, and the solvent in the solvent container 60 can be sucked into the solvent chamber 63.

  With such a configuration, the ink chamber 27 and the solvent chamber 63 of the pressure chamber 320 are formed integrally with the first manifold plate 303 and the second manifold plate 304 that form the internal flow path of the circulation unit 320. . Therefore, the housing parts of the ink chamber 27 and the solvent chamber 63 and the sealing parts between the housing part and the manifold plate are not necessary. Furthermore, the installation space for the pressure chamber 320 is not required on the manifold. As a result, the pressure chamber 320 can be disposed without using the space reduced by eliminating the solvent pump. Further downsizing of the recording apparatus can be realized.

DESCRIPTION OF SYMBOLS 1 ... Main-body part, 2 ... Print head part, 3 ... Operation display part, 4 ... Conduit, 5 ... Belt conveyor, 6 ... Print object, 7 ... Encoder, 8 ... Print sensor, 9 ... Nozzle, 10 ... Ink particle, DESCRIPTION OF SYMBOLS 11 ... Charging electrode, 12 ... Deflection electrode, 14 ... Gutter, 15 ... Electromagnetic valve, 17 ... Ink column, 18 ... Electrostrictive element, 20 ... Main ink container, 21 ... Liquid level detection sensor, 22 ... Electromagnetic valve, 23 ... Pump (for ink supply), 24 ... Viscosity measuring device, 25 ... Solenoid valve, 20 ... Solvent container, 21 ... Viscosity measuring device, 22 ... Solenoid valve, 23 ... Solenoid valve, 24 ... Solenoid valve, 25 ... Pump (ink supply) ), 26 ... Diaphragm, 27 ... Ink chamber, 28 ... Filter (for supply), 29 ... Pressure reducing valve, 30 ... 3-port solenoid valve, 40 ... Pressure gauge, 41 ... Solenoid valve, 50 ... Pump (for collecting ink) 51 ... filter (for recovery), 60 ... solvent container 61 ... Solvent filter, 62 ... Check valve, 63 ... Solvent chamber, 64 ... Solenoid valve, 65 ... Solenoid valve, 70 ... Solenoid valve, 80 ... Ink container (for replenishment), 81 ... Solenoid valve, 100 ... Inkjet recording Device, 101-112 ... route, 120-124 ... route, 130-133 ... route, 200 ... control unit, 201 ... bus line, 202 ... recording unit, 300 ... circulation unit, 301 ..Ink circulation unit, 302 ... solvent circulation unit, 303 ... first manifold plate, 304 ... second manifold plate, 310 ... motor, 311 ... cam, 320 ... pressure chamber , 330 ... Piping joint, 340 ... Flange, 350 ... Through hole (diaphragm), 351 ... Projection (center disk), 352 ... Sen -Disk, 353 ... hole (spring), 354 ... spring, 360 ... bead (diaphragm), 362 ... groove, 365 ... compression spring, 367 ... step, 400 ...・ O-ring

Claims (4)

An ink container for holding ink;
Pressurizing means for pressurizing the ink in the ink container and ejecting from the nozzle;
Gutter to supplement ink particles not used for printing,
A collecting means for collecting the ink captured by the gutter into the ink container;
A solvent container holding a solvent used for cleaning the nozzle and diluting the ink;
In an inkjet recording apparatus comprising:
An ink circulation unit in which a pump, solenoid valve, pipe connection port , and ink chamber are mounted on a manifold plate in which a flow path for ink is formed, and a solenoid valve on a manifold plate in which a flow path for solvent is formed. connection port includes a solvent circulation unit equipped with solvent chamber, a,
The solvent circulation unit and the ink circulation unit includes the ink container by closely fixed via a solvent chamber to face the film-like elastic body of the solvent circulation unit and an ink chamber of the ink circulation unit An ink jet recording apparatus comprising a pressure chamber for supplying a solvent to the nozzle and constituting an integrated circulation unit. Said pressure chamber by said film-like elastic member is displaced is pressurized in ink pressure, ink jet recording apparatus according to claim 1, wherein the extruding the solvent supplied to the flow path.   2. The ink jet recording apparatus according to claim 1, wherein a pump is integrally formed on a surface of the manifold plate of the ink circulation unit opposite to the close surface of the solvent circulation unit.   4. The ink jet recording apparatus according to claim 3, wherein the pump is a pump that supplies ink to the nozzle and a pump that supplements ink particles that are not used for printing and collects them in the ink container.

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