JP2018103141A - Liquid filling method in liquid discharge device and liquid discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique capable of efficiently filling liquid to a discharge port.SOLUTION: A method for filling liquid to a storage chamber and a discharge port of a liquid discharge device, comprises: a storage chamber filling step of moving a movable body toward the discharge port, closing the discharge port, and subsequently filling the storage chamber with the liquid; and a discharge port filling step of separating the movable body from the discharge port, opening the discharge port and causing the liquid to flow in the discharge port. The discharge port filling step includes a pressure control step of controlling at least one of inflow of the liquid from an inflow port such that the liquid flows into the discharge port when opening the discharge port, and outflow of the liquid from an outflow port and adjusting a pressure in the storage chamber.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a liquid filling method and a liquid ejection apparatus in a liquid ejection apparatus.

  Conventionally, various liquid ejection devices that eject liquid from ejection ports have been proposed. For example, Patent Document 1 below discloses a coating apparatus that forms a thin film such as a resist by discharging a coating liquid onto a semiconductor wafer from a nozzle that forms a discharge port. Other known liquid ejection devices include an inkjet printer that produces a printed material by ejecting ink from a head having an ejection port, and a 3D printer that shapes a three-dimensional object by ejecting a liquid material from the ejection port. .

Japanese Patent Laid-Open No. 2006-159213

  In general, in a liquid ejecting apparatus, in order to suppress the occurrence of defective liquid ejection, it is desirable to start the ejection process for ejecting liquid after the ejection port is filled with liquid. When filling the discharge port with the liquid, there is a problem that the liquid is wasted if the liquid leaks from the discharge port. Further, when air enters the discharge port and bubbles are generated in the liquid, there is a problem that it causes a discharge failure of the liquid.

  In the technique of the above-mentioned Patent Document 1, before filling the liquid flow path provided with the nozzle in the coating head with the coating liquid, a non-coating liquid for suppressing the remaining of bubbles is applied to the wall surface of the liquid flow path. It is attached. In the technique of Patent Document 1, a process for processing the non-application liquid, such as filling and discharging the non-application liquid in the liquid flow path, is necessary before filling the discharge port with the liquid. There is a possibility. In a liquid discharge apparatus, in order to make a liquid dischargeable satisfactorily, a technique capable of more efficiently filling a discharge port with liquid before discharge processing is desired.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

[1] According to one aspect of the present invention, a storage chamber for storing a liquid, a discharge port for discharging the liquid from the storage chamber, an inflow port for allowing the liquid to flow into the storage chamber, and the storage A liquid discharge apparatus comprising: a storage chamber having an outlet for allowing the liquid to flow out of the chamber; and a moving body that moves toward the discharge port in the storage chamber and discharges the liquid from the discharge port. There is provided a method of filling the storage chamber and the discharge port with the liquid before executing a discharge process for discharging the liquid from the discharge port. This method includes a storage chamber filling step and a discharge port filling step. In the storage chamber filling step, the moving body is moved toward the discharge port, the discharge port is closed by the moving body, the liquid is then introduced from the inflow port, and the storage chamber is moved into the storage chamber. It may be a step of filling with a liquid. The discharge port filling step may be a step of separating the moving body from the discharge port, opening the discharge port, and allowing the liquid to flow into the discharge port. In the discharge port filling step, when the discharge port is opened, the pressure of the liquid flowing in from the inflow port and the pressure of the liquid flowing out from the outflow port so that the liquid flows into the discharge port And a pressure control step of controlling the pressure in the storage chamber by controlling at least one of them.
According to the method of this aspect, in a liquid discharge apparatus of a type that discharges liquid from the discharge port by the movement of the moving body in the storage chamber, it is possible to suppress leakage of liquid from the discharge port and entry of outside air into the discharge port. The liquid can be efficiently filled into the discharge port. Therefore, it is possible to suppress the occurrence of ejection failure in the ejection process.

[2] In the method of the above aspect, when the pressure of the liquid in the storage chamber is Pc, the atmospheric pressure outside the storage chamber is Po, and the meniscus pressure resistance of the liquid at the discharge port is Pm, the pressure control The step may be a step of controlling the pressure in the accommodation chamber so as to satisfy a relationship of Po−Pm <Pc <Po + Pm.
According to the method of this aspect, it is possible to allow the liquid to flow into the discharge port while maintaining the state in which the meniscus is formed in the liquid at the discharge port. Therefore, it is possible to efficiently fill the discharge port with liquid while suppressing leakage of liquid from the discharge port and entry of outside air into the discharge port.

[3] The method of the above aspect may further include a blocking step of closing the discharge port by the moving body and blocking the inflow of the liquid into the discharge port after the discharge port filling step is started.
According to the method of this embodiment, the discharge port can be closed by the moving body while the discharge port is filled with the liquid.

[4] In the method of the above aspect, the liquid has a property of decreasing in viscosity by application of a shearing force, and the discharge port filling step applies the shearing force to the liquid in the storage chamber by the movement of the moving body. May be included to lower the viscosity of the liquid.
According to this form of the method, the inflow of the liquid into the discharge port is promoted by the decrease in the viscosity of the liquid. Therefore, it is possible to increase the filling speed of the liquid into the discharge port.

[5] According to another aspect of the present invention, there is provided a liquid ejection apparatus that performs an ejection process for ejecting liquid from an ejection port. The liquid ejection device includes a storage chamber that stores the liquid and has the discharge port; a supply unit that allows the liquid to flow into the storage chamber; an outflow unit that allows the liquid to flow out of the storage chamber; and the storage chamber A moving body that moves toward the discharge port and discharges the liquid from the discharge port, and a closing operation that closes the discharge port; and the liquid into the storage chamber by the supply unit A controller that controls the supply of the liquid, the outflow of the liquid from the storage chamber by the outflow unit, and the movement of the moving body. Prior to the execution of the discharge process, the control unit causes the movable body to perform the closing operation and closes the discharge port as a filling process for filling the storage chamber and the discharge port with the liquid. A storage chamber filling process in which the liquid flows into the storage chamber to fill the storage chamber with the liquid, and after the storage chamber filling process, the movable body is separated from the discharge port to open the discharge port. And a discharge port filling process for causing the liquid to flow into the discharge port. The discharge port filling process includes the pressure of the liquid flowing into the storage chamber and the pressure of the liquid flowing out of the storage chamber so that the liquid flows into the discharge port when the discharge port is opened. , And a pressure adjustment process for adjusting the pressure in the accommodation chamber by controlling at least one of them.
According to the liquid ejection device of this aspect, it is possible to efficiently fill the ejection port with liquid while suppressing leakage of liquid from the ejection port and entry of outside air into the ejection port. Therefore, it is possible to suppress the occurrence of ejection failure in the ejection process.

  A plurality of constituent elements of each aspect of the present invention described above are not indispensable, and some or all of the effects described in the present specification are to be solved to solve part or all of the above-described problems. In order to achieve the above, it is possible to appropriately change, delete, replace with a new other component, and partially delete the limited contents of some of the plurality of components. In order to solve part or all of the above-described problems or to achieve part or all of the effects described in this specification, technical features included in one embodiment of the present invention described above. A part or all of the technical features included in the other aspects of the present invention described above may be combined to form an independent form of the present invention.

  The present invention can also be realized in various forms other than the liquid filling method and the liquid discharge apparatus in the liquid discharge apparatus. For example, the present invention can be realized in the form of a liquid ejection device control method, a liquid filling method, a liquid ejection device control method, a non-temporary recording medium on which the computer program is recorded, or the like.

FIG. 2 is a schematic diagram illustrating a configuration of a liquid ejection device according to the first embodiment. Explanatory drawing which shows the flow of the discharge preparation process of 1st Embodiment. The schematic diagram which shows the state of the storage chamber in the process a of discharge preparation processing. The schematic diagram which shows the state of the storage chamber in the process b of discharge preparation processing. The schematic diagram which shows the state of the storage chamber in the process d of discharge preparation processing. The schematic diagram which shows the state of the storage chamber in the process e of discharge preparation processing. Explanatory drawing which shows the flow of the discharge preparation process of 2nd Embodiment. The schematic diagram which shows the state of the storage chamber in the process f of the discharge preparation process of 2nd Embodiment. Explanatory drawing which shows the flow of the discharge preparation process of 3rd Embodiment. Explanatory drawing which shows the flow of the discharge preparation process of 4th Embodiment.

A. First embodiment:
FIG. 1 is a schematic diagram illustrating a configuration of a liquid ejection apparatus 100 according to the first embodiment. FIG. 1 shows an arrow G indicating the direction of gravity (vertical direction) when the liquid ejection device 100 is arranged in a normal use state. In this specification, “upper” or “lower” means a direction based on the vertical direction unless otherwise specified.

  The liquid ejection apparatus 100 is a 3D printer that is a three-dimensional modeling apparatus, and forms a three-dimensional object by stacking layers in which the liquid FL is ejected and the liquid FL is cured. In this specification, the term “ejection” means that the liquid is discharged from the inside of the contained space to the outside by some force including gravity, and is a concept including “jet” that discharges the liquid by pressure. is there. A specific example of the liquid FL that is ejected by the liquid ejection device 100 as a material of a three-dimensional object that is a modeling object will be described later.

  The liquid ejection device 100 includes the ejection unit 10, the supply unit 50, the outflow unit 55, the modeling stage 60, the moving mechanism 65, the energy application unit 70, and the control unit 101. Hereinafter, each of these components 10, 50, 55, 60, 65, 70, 101 will be described in order.

[Discharge part]
The discharge unit 10 corresponds to a head in a 3D printer, and discharges the liquid FL, which is a liquid material having fluidity, in the form of droplets. The shape of the droplet is not limited, and may be spherical, or may be a shape in which the spherical shape is extended in one direction, a needle shape, a rod shape, or a thread shape. Further, the number of droplets discharged per discharge is not limited to one, and a plurality of droplets may be discharged.

  The discharge unit 10 includes a head main body 11. In the present embodiment, the head main body 11 is configured as a hollow container having a substantially cylindrical shape. The head main body 11 is made of a metal such as stainless steel, for example. The head main body 11 is provided with a storage chamber 12 and a drive chamber 14.

  The storage chamber 12 is provided at the lower end of the head main body 11. The storage chamber 12 stores the liquid FL that is a discharge target of the discharge unit 10. In the present embodiment, the storage chamber 12 is configured by a substantially columnar cavity.

  A discharge port 15 that functions as a nozzle for discharging the liquid FL is provided at the lower end of the storage chamber 12. The discharge port 15 is provided as a through hole that communicates from the storage chamber 12 to the outside of the head main body 11, and opens at the bottom surface 11 b of the head main body 11. In the present embodiment, the discharge port 15 has a substantially cylindrical internal space. The central axis NX of the discharge port 15 is a direction along the vertical direction, and opens downward in the bottom surface 11 b of the head main body 11. The opening diameter of the discharge port 15 may be about 10 to 200 μm, for example. The length of the discharge port 15 in the vertical direction may be about 10 to 30 μm, for example.

  It is desirable that an enlarged opening 16 is provided above the discharge port 15. The enlarged opening 16 is an opening located above the discharge port 15 and connected to the discharge port 15. In the enlarged opening 16, the opening area becomes larger as it is closer to the distal end 21 of the moving body 20. The liquid FL is guided to the discharge port 15 by the enlarged opening 16. The enlarged opening 16 may be omitted.

  A supply channel 17 for receiving a liquid FL pumped from a supply unit 50 described later is connected to the storage chamber 12 from the side. The supply flow channel 17 is configured as a conduit that penetrates the outer wall of the head main body 11. In the side wall surface 12 w of the storage chamber 12, an inflow port 17 o through which the liquid FL flows from the supply flow path 17 into the storage chamber 12 is opened.

  A discharge channel 18 for allowing the liquid FL in the storage chamber 12 to flow out to an outflow portion 55 described later is connected to the storage chamber 12 from the side. The discharge channel 18 is configured as a conduit that penetrates the outer wall of the head main body 11. An outlet 18 o through which the liquid FL flows from the storage chamber 12 to the discharge flow path 18 is opened on the side wall surface 12 w of the storage chamber 12.

  The drive chamber 14 is located above the storage chamber 12 and stores a piezoelectric element 31 of the drive unit 30 described later. In the present embodiment, a seal member 19 is disposed at the boundary between the storage chamber 12 and the drive chamber 14. The seal member 19 is configured by, for example, a resin O-ring.

  The discharge unit 10 further includes a moving body 20 and a drive unit 30. The moving body 20 is disposed across the accommodation chamber 12 and the drive chamber 14 of the head main body 11. In this embodiment, the moving body 20 is comprised by the shaft-shaped member which has a substantially cylindrical main-body part. The moving body 20 is comprised by metals, such as stainless steel, for example. The diameter of the moving body 20 may be about 0.3 to 5 mm.

  In the present embodiment, the moving body 20 is arranged such that the central axis CX coincides with the central axis NX of the discharge port 15. The moving body 20 is hermetically inserted through the central through hole of the seal member 19 and is held in a state in which movement in the direction along its own central axis CX is allowed. In addition, when the seal member 19 is in close contact with the side surface of the moving body 20, the liquid FL in the storage chamber 12 is suppressed from entering the drive chamber 14.

  The moving body 20 moves in a direction toward the discharge port 15 and in a direction away from the discharge port 15. In the present embodiment, the moving direction of the moving body 20 is a direction along the central axis CX of the moving body 20 and a direction along the vertical direction. The movable range of the moving body 20 may be, for example, about 10 to 500 μm.

  The distal end portion 21 of the moving body 20 is disposed at a position facing the discharge port 15 in the storage chamber 12. In the discharge process in the liquid discharge apparatus 100, the moving body 20 moves in the direction toward the discharge port 15, and the liquid FL in the storage chamber 12 is pushed out from the discharge port 15 to the distal end portion 21 of the moving body 20. Liquid droplets of liquid FL are ejected.

  The distal end portion 21 of the moving body 20 contacts the peripheral edge of the discharge port 15 to close the discharge port 15 when the moving body 20 is closest to the discharge port 15. It is desirable that the tip portion 21 is configured to be in line contact with the peripheral portion of the discharge port 15 when closing the discharge port 15. Therefore, it is desirable that the tip portion 21 has a substantially hemispherical shape that is convex toward the discharge port 15. The diameter of the tip 21 is preferably larger than the opening diameter of the discharge port 15 and smaller than the opening diameter at the upper end of the enlarged opening 16.

  The driving unit 30 generates a driving force for moving the moving body 20. In the present embodiment, the drive unit 30 includes a piezoelectric element 31 housed in the drive chamber 14 and a drive circuit 32. The piezoelectric element 31 is also called a piezo element, and has a configuration in which a plurality of piezoelectric materials are stacked, and the length changes in the stacking direction according to the voltage applied to each piezoelectric material. . One end of the piezoelectric element 31 in the stacking direction is fixed to the upper wall surface of the drive chamber 14, and the other end is connected to a rear end located at the upper end of the moving body 20. The driving circuit 32 applies an electric driving force for expanding and contracting the piezoelectric element 31 under the control of the control unit 101. The drive unit 30 displaces the moving body 20 by expansion / contraction deformation of the piezoelectric element 31.

  In addition to the piezoelectric element 31, the driving chamber 14 is provided with an elastic force in a direction in which the moving body 20 is moved away from the discharge port 15, and an urging member that pushes the moving body 20 toward the piezoelectric element 31. May be arranged. A connecting member that connects the moving body 20 and the piezoelectric element 31 may be disposed between the moving body 20 and the piezoelectric element 31.

[Supply section]
The supply unit 50 controls the inflow of the liquid FL into the storage chamber 12 of the discharge unit 10. The supply unit 50 pumps the liquid FL through the supply channel 17. The supply unit 50 includes a pipe 51, a liquid storage unit 52, and a pressure generation unit 53. The pipe 51 connects the supply channel 17 of the head main body 11 and the liquid storage unit 52. The liquid storage unit 52 is a supply source of the liquid FL in the liquid ejection apparatus 100, and is configured by a tank that stores the liquid FL. In the liquid storage unit 52, the viscosity of the liquid FL is maintained at a predetermined viscosity by mixing the solvent with the stored liquid FL. The viscosity of the liquid FL may be, for example, about 50 to 40,000 mPa · s.

  The pressure generating unit 53 is configured by a pressurizing pump, for example. The pressure generation unit 53 applies pressure for pressure-feeding the liquid FL in the liquid storage unit 52 to the head main body 11 via the pipe 51. The pressure generating unit 53 applies a pressure of about 0.4 to 0.6 MPa to the liquid FL, for example. In FIG. 1, the pressure generator 53 is provided on the upstream side of the liquid reservoir 52, but the pressure generator 53 may be provided on the downstream side of the liquid reservoir 52.

[Outflow part]
The outflow part 55 controls the outflow of the liquid FL from the storage chamber 12. The outflow portion 55 causes the liquid FL in the storage chamber 12 to flow out of the head main body portion 11 through the discharge flow path 18. In the present embodiment, the outflow portion 55 functions as a circulation portion that circulates the liquid FL that has flowed out of the storage chamber 12 to the supply portion 50. The outflow part 55 includes a pipe 57 connected to the discharge flow path 18 and a flow rate adjusting part 58 that adjusts the flow rate of the liquid FL in the pipe 57. The liquid FL that has flowed out of the storage chamber 12 flows into the pipe 57 through the outlet 18o. In the present embodiment, the pipe 57 is connected to the liquid storage unit 52 of the supply unit 50, and the liquid FL of the pipe 57 is circulated to the liquid storage unit 52.

  The flow rate adjusting unit 58 adjusts the flow rate of the liquid FL in the pipe 57 under the control of the control unit 101. The flow rate adjusting unit 58 is configured by, for example, a suction pump that sucks the liquid FL from the storage chamber 12. For example, in the discharge process of the liquid FL, the flow rate adjusting unit 58 sets the flow rate of the liquid FL in the pipe 57 so that the internal pressure of the storage chamber 12 is maintained at a pressure suitable for discharging the liquid FL from the discharge port 15. Adjust.

  Since the liquid discharge device 100 includes the outflow portion 55, the liquid discharge device 100 moves from the inflow port 17o to the outflow port 18o in the storage chamber 12 during the execution of the discharge process or in a standby state where the discharge process is suspended. A flow of liquid FL can be generated. As a result, the particles contained in the liquid FL are prevented from staying in the storage chamber 12. Further, deterioration of the liquid FL, such as a change in the concentration of the liquid FL due to evaporation of the solvent component, can be suppressed, and the liquid FL can be maintained in a state suitable for ejection.

[Modeling stage and moving mechanism]
The modeling stage 60 is disposed at the tip of the discharge port 15 in the opening direction of the discharge unit 10. The discharge unit 10 discharges the liquid FL using the modeling stage 60 as a target object. A three-dimensional object is modeled by the liquid FL droplets that have landed on the modeling stage 60. In the present embodiment, the modeling stage 60 is configured by a flat plate-like member and is disposed substantially horizontally. The modeling stage 60 is arrange | positioned in the position which left | separated about 1.5-3 mm vertically downward from the discharge outlet 15, for example.

  The moving mechanism 65 includes a motor, a roller, a shaft, and various actuators for displacing the modeling stage 60 with respect to the discharge unit 10. The moving mechanism 65 displaces the modeling stage 60 in the horizontal direction indicated by the arrow Y and the vertical direction indicated by the arrow X relative to the discharge unit 10. Thereby, the landing position of the liquid FL on the modeling stage 60 is adjusted. In addition, in the liquid discharge apparatus 100, the position of the modeling stage 60 may be fixed, and the discharge part 10 may be comprised with respect to the modeling stage 60 with a moving mechanism.

[Energy application section]
The energy applying unit 70 applies energy to the liquid FL that has landed on the modeling stage 60 and cures it. In this embodiment, the energy provision part 70 is comprised by the laser apparatus, and provides optical energy to the liquid FL by laser irradiation. The energy applying unit 70 includes at least a laser light source, a condensing lens for condensing the laser emitted from the laser light source on the liquid FL landed on the modeling stage 60, a galvanometer mirror for scanning the laser, (Not shown). The energy applying unit 70 scans the landing position of the droplet on the modeling stage 60 with a laser, and sinters the powder material in the liquid FL with the light energy of the laser. Alternatively, the powder material in the liquid FL is once melted and bonded. Thereby, a material layer constituting the three-dimensional object is formed on the modeling stage 60.

  The energy applying unit 70 may cure the liquid FL by a method other than laser irradiation. The energy applying unit 70 may cure the liquid FL by irradiation with ultraviolet rays, or may remove at least a part of the solvent of the liquid FL by heating with a heater and cure the powder material. In addition, the three-dimensional object modeled on the modeling stage 60 may be subjected to a sintering process in a heating furnace as necessary.

[Control unit]
The control unit 101 is configured by a computer including at least a central processing unit (CPU) and a main storage device (RAM). The control unit 101 performs various functions for controlling the liquid ejection apparatus 100 by reading and executing a computer program on the RAM. The control unit 101 controls the discharge unit 10, the supply unit 50, the outflow unit 55, the moving mechanism 65, and the energy applying unit 70 described above.

  The control unit 101 controls the drive unit 30 of the discharge unit 10 to control the movement of the moving body 20. The control unit 101 moves the moving body 20 toward the ejection port 15 and ejects the liquid FL from the ejection port 15, and the obstruction that moves toward the ejection port 15 and closes the ejection port 15. To perform actions. The control unit 101 controls the pressure in the storage chamber 12 by controlling the pressure generated by the pressure generation unit 53 of the supply unit 50 and the pressure generated by the flow rate adjustment unit 58 of the outflow unit 55. The control unit 101 controls the moving mechanism 65 to displace the modeling stage 60 with respect to the ejection unit 10 and controls the landing position of the liquid FL droplet on the modeling stage 60. The control unit 101 drives the energy applying unit 70 in accordance with the discharge timing of the liquid FL by the discharge unit 10 to cure the liquid FL attached to the modeling stage 60. The control unit 101 executes a discharge preparation process for filling the storage chamber 12 and the discharge port 15 with the liquid FL prior to the discharge process for discharging the liquid FL from the discharge port 15 of the discharge unit 10. Details of the discharge preparation process will be described later.

[Specific examples of liquid]
With the above configuration, the liquid ejection device 100 according to the present embodiment forms a three-dimensional object using the liquid FL to be ejected as a material. A specific example of the liquid FL that is a material of the three-dimensional object will be described. In the present embodiment, the liquid FL is a paste-like fluid composition containing a powder material and a solvent. The liquid FL may include a powder material and a solvent. As a powder material, for example, magnesium (Mg), iron (Fe), cobalt (Co), chromium (Cr), aluminum (Al), titanium (Ti), copper (Cu), nickel (Ni) simple powder, Alternatively, alloy powders containing one or more of these metals (maraging steel, stainless steel, cobalt chromium molybdenum, titanium alloy, nickel alloy, aluminum alloy, cobalt alloy, cobalt chromium alloy), or a single powder or alloy powder are selected. 1 type or 2 types or more mixed powders may be used. The solvent of the liquid FL is, for example, water; (poly) alkylene glycol monoalkyl ethers such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether; ethyl acetate, n-propyl acetate Acetates such as iso-propyl acetate, n-butyl acetate and iso-butyl acetate; aromatic hydrocarbons such as benzene, toluene and xylene; methyl ethyl ketone, acetone, methyl isobutyl ketone, ethyl n-butyl ketone, diisopropyl ketone , Ketones such as acetylacetone; alcohols such as ethanol, propanol, butanol; tetraalkylammonium acetates; dimethyl sulfoxide, diethyl sulfoxide, etc. Sulfoxide solvents; pyridine solvents such as pyridine, γ-picoline, 2,6-lutidine; ionic liquids such as tetraalkylammonium acetate (for example, tetrabutylammonium acetate), or one or two selected from these It may be a combination of more than one species.

  The liquid FL may be a mixed material in which the above powder material and solvent are mixed with a binder to form a slurry or a paste. The binder may be, for example, an acrylic resin, an epoxy resin, a silicone resin, a cellulosic resin or other synthetic resin, PLA (polylactic acid), PA (polyamide), PPS (polyphenylene sulfide), or other thermoplastic resin. . The liquid FL is not limited to those containing the above powder material. For example, the liquid FL is obtained by melting a resin such as general-purpose engineering plastics such as polyamide, polyacetal, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, and polyethylene terephthalate. Also good. In addition, the liquid FL may be a resin such as engineering plastics such as polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, polyimide, polyamideimide, polyetherimide, and polyetheretherketone. The liquid FL may contain metals other than the above metals, ceramics, resins, and the like. The liquid FL may contain a sintering aid.

[Discharge preparation process]
With reference to FIG. 2 and FIGS. 3A to 3D, the ejection preparation process executed in the liquid ejection apparatus 100 will be described. FIG. 2 is an explanatory diagram illustrating a flow of the discharge preparation process in the first embodiment. 3A to 3D are schematic views showing the state of the storage chamber 12 of the discharge unit 10 in each step of the discharge preparation process. This discharge preparation process is performed when the storage chamber 12 is empty for some reason, for example, after setup or maintenance of the liquid discharge device 100 or immediately after startup, or the liquid FL is not sufficiently supplied to the storage chamber 12. Sometimes, it is executed prior to the execution of the discharge process.

  In the discharge preparation process, the control unit 101 sequentially executes the storage chamber filling process P1 and the discharge port filling process P2. In the storage chamber filling process P1, storage chamber filling steps a and b, which are steps of filling the storage chamber 12 whose discharge port 15 is closed by the moving body 20 with the liquid FL, are executed. In step a, the control unit 101 moves the moving body 20 toward the discharge port 15 to close the discharge port 15 (FIG. 3A).

  After closing the discharge port 15, in step b, the control unit 101 drives the supply unit 50 to cause the liquid FL to flow into the storage chamber 12 through the inflow port 17 o, so that the storage chamber 12 is filled with the liquid FL. (Fig. 3B). In step b, the control unit 101 may only pump the liquid FL by the supply unit 50. Alternatively, the control unit 101 drives the flow rate adjusting unit 58 of the outflow unit 55 to supply the liquid FL to the storage chamber 12 by the supply unit 50 while sucking the liquid FL flowing into the storage chamber 12 from the outlet 18o. It is good also as what makes it.

  After the internal space of the storage chamber 12 is filled with the liquid FL, the control unit 101 starts the discharge port filling process P2. In the discharge port filling process P <b> 2, discharge port filling steps c to e, which are steps for causing the liquid FL to flow into the internal space of the discharge port 15, are executed. Step c is a pressure control step for executing a pressure adjustment process for adjusting the pressure in the storage chamber 12. In step c, the pressure of the liquid FL in the storage chamber 12 is adjusted so that the liquid FL flows into the discharge port 15 when the discharge port 15 is opened in the subsequent step d.

  In step c, when the discharge port 15 is opened, the liquid FL gently flows into the internal space of the discharge port 15 so that a low pressure near atmospheric pressure (for example, atmospheric pressure is about ± 3 to 5%). It is desirable that the pressure be adjusted. In step c, at least the pressure around the distal end portion 21 of the moving body 20 is adjusted to be positive.

In step c, it is desirable that the pressure Pc of the liquid FL in the storage chamber 12 be adjusted so as to satisfy the relationship of the following inequality (1).
Po−Pm <Pc <Po + Pm (1)

Po is the atmospheric pressure outside the storage chamber 12, and Pm is the meniscus pressure resistance of the liquid FL at the discharge port 15. The “meniscus pressure resistance at the discharge port 15” refers to a pressure that can withstand the meniscus of the liquid FL without being destroyed at the discharge port 15. The meniscus pressure resistance Pm can be obtained by the following equation (2), for example. The following surface tension T and contact angle θ are values determined by the type of liquid FL, the state of its concentration and viscosity, the type of member on which the discharge port 15 is formed, and the surface properties at the discharge port 15. It is a value obtained experimentally in advance.
Pm = 2 · T · cos θ / r (2)
T: Surface tension [N / m]
θ: Contact angle [°]
r: radius of the discharge port 15

  In step c, the pressure generated in the pressure generation unit 53 of the supply unit 50 may be controlled to adjust the flow rate of the liquid FL flowing into the storage chamber 12 and to adjust the pressure of the liquid FL in the storage chamber 12. . Alternatively, in step c, the flow rate of the liquid FL flowing into the storage chamber 12 is adjusted by the pressure generation unit 53 of the supply unit 50, and the flow rate of the liquid FL flowing out of the storage chamber 12 is adjusted by the flow rate adjustment unit 58 of the outflow unit 55. The pressure of the liquid FL in the storage chamber 12 may be adjusted by adjusting the flow rate.

  In step d, the control unit 101 moves the moving body 20 in a direction away from the discharge port 15 to open the discharge port 15 (FIG. 3C). Then, the liquid FL flows into the discharge port 15 using the pressure of the liquid FL in the storage chamber 12 adjusted in step c as a driving force. In step d, it is desirable to move the moving body 20 at a moderate speed. It is desirable to move the moving body 20 at a slower speed than when moving in a direction away from the discharge port 15 at least in the discharge process. Thereby, the generation of a sudden negative pressure due to the movement of the moving body 20 is suppressed, and the entry of outside air from the discharge port 15 is suppressed.

  If the pressure Pc of the liquid FL in the storage chamber 12 is adjusted to a pressure that satisfies the relationship of the inequality (1), a meniscus of the liquid FL that is convex or concave downward is formed in the discharge port 15. It is formed. Therefore, outside air can be prevented from entering the storage chamber 12 through the discharge port 15. Further, it is possible to prevent the liquid FL from suddenly flowing into the discharge port 15 and flowing out from the discharge port 15.

  In step e, the process waits while maintaining the pressure state of the liquid FL in the storage chamber 12 in step d until the discharge port 15 is filled with a predetermined amount of the liquid FL (FIG. 3D). The standby time in step e may be a time experimentally determined in advance. Further, the prescribed amount of the liquid FL filled in the discharge port 15 may not be an amount that completely fills the internal space in the discharge port 15, and is experimentally determined in advance as a suitable amount for discharging the liquid FL. In the amount given.

  After waiting in step e, the discharge preparation process is completed, and the discharge unit 10 is ready to start the discharge process. After step e, the pressure Pc of the liquid FL in the storage chamber 12 is adjusted so as to satisfy the relationship of the above inequality (1), so that the discharge port 15 remains open by the moving body 20. The state in which the liquid FL leaks from 15 is suppressed.

  In the liquid ejection apparatus 100 according to the present embodiment, as illustrated in FIG. 3D, the ejection process of the liquid FL is started from the state where the ejection port 15 is open. The control unit 101 may cause the liquid FL to be discharged from the discharge port 15 by instantaneously moving the moving body 20 toward the discharge port 15 from the state shown in FIG. 3D. Alternatively, the control unit 101 moves the moving body 20 in a direction further away from the discharge port 15 from the state shown in FIG. The liquid FL may be ejected from the liquid. The controller 101 may move the moving body 20 until the discharge port 15 is closed by the distal end portion 21 of the moving body 20 when the liquid FL is discharged, or the distal end portion 21 of the moving body 20 may be the discharge port. The moving body 20 may be stopped before reaching 15.

  As described above, according to the liquid discharge device 100 of this embodiment and the liquid FL filling method executed in the discharge preparation process, the liquid to the discharge port 15 is adjusted by adjusting the pressure Pc of the liquid FL in the storage chamber 12. Rapid inflow of FL is suppressed. Accordingly, the filling of the liquid FL into the discharge port 15 is facilitated. Further, by adjusting the pressure Pc of the liquid FL in the storage chamber 12 to a pressure satisfying the relationship of the above inequality (1), leakage of the liquid FL from the discharge port 15 and entry of outside air into the discharge port 15 are suppressed. Is done. In addition, according to the liquid ejection device 100 of the present embodiment and the liquid FL filling method executed in the ejection preparation process, the various effects described in the above embodiments can be achieved.

B. Second embodiment:
FIG. 4 is an explanatory diagram illustrating a flow of the discharge preparation process in the second embodiment. The ejection preparation process of the second embodiment is executed in a liquid ejection apparatus having the same configuration as the liquid ejection apparatus 100 (FIG. 1) described in the first embodiment. The discharge preparation process of the second embodiment is substantially the same as the discharge preparation process (FIGS. 2, 3A to 3D) of the first embodiment except for the points described below.

  In the discharge preparation process of the second embodiment, in the storage chamber filling process P1, the storage chamber filling steps a and b are executed in the same manner as described in the first embodiment (FIGS. 3A and 3B). In the pressure adjustment process of step c executed in the discharge port filling process P2 after the internal space of the storage chamber 12 is filled with the liquid FL, the pressure of the liquid FL in the storage chamber 12 has been described in the first embodiment. The pressure may be adjusted to the same low pressure. Alternatively, in step c of the second embodiment, the pressure of the liquid FL in the storage chamber 12 may be adjusted to a pressure higher than the pressure described in the first embodiment. By adjusting the pressure of the liquid FL in the storage chamber 12 to a high pressure, the liquid FL can be filled into the discharge port 15 in a short period of time after the discharge port 15 is opened in the step d.

  In step d, after moving the moving body 20 and opening the discharge port 15 (FIG. 3C), in step e, the process waits until the discharge port 15 is filled with a predetermined amount of liquid FL. (FIG. 3D). The standby time in the process e becomes shorter as the pressure of the liquid FL in the storage chamber 12 is higher. The standby time in step e may be determined according to the pressure of the liquid FL in the storage chamber 12 adjusted in step c.

  FIG. 5 is a schematic diagram illustrating a state of the storage chamber of the discharge unit in step f of the discharge preparation process of the second embodiment. After executing the steps c to e of the discharge port filling process P2, the control unit 101 moves the moving body 20 toward the discharge port 15 and closes the discharge port 15 with the tip 21 of the moving body 20, A blocking step f for blocking the inflow of the liquid FL into the discharge port 15 is executed (FIG. 5). Thus, the discharge port 15 can be closed while the liquid FL is held in the internal space of the discharge port 15.

  In step f, it is desirable to move the moving body 20 toward the discharge port 15 gently so that the liquid FL does not leak from the discharge port 15. In step f, it is desirable that the moving body 20 is moved at a speed that is slower than at least when moving the moving body 20 toward the discharge port 15 in the discharge process. Further, in the step f, the amount of the liquid FL flowing into the discharge port 15 is taken into consideration by moving the moving body 20 toward the discharge port 15 before the discharge port 15 is filled with the liquid FL in the step e. It is desirable to start execution. That is, it is desirable that the prescribed amount of the liquid FL that flows into the discharge port 15 during the standby period of the step e is smaller than the volume of the discharge port 15. In step f, after the discharge port 15 is closed, the pressure of the liquid FL in the storage chamber 12 may be adjusted to a pressure suitable for the discharge process, or may be changed to another pressure.

  According to the discharge preparation process of the second embodiment, since the discharge port 15 is closed while the discharge port 15 is filled with the liquid FL, the liquid FL leaks from the discharge port 15 after the completion of the discharge preparation process. It is suppressed. In addition, the filling of the liquid FL into the discharge port 15 can be easily realized by adjusting the standby time in the step e instead of the pressure adjustment in the pressure adjustment process. In addition, according to the liquid ejection device of the second embodiment and the method of filling the liquid FL executed in the ejection preparation process, various functions and effects similar to those described in the first embodiment can be achieved.

C. Third embodiment:
FIG. 6 is an explanatory diagram illustrating a flow of the discharge preparation process in the third embodiment. The ejection preparation process of the third embodiment is executed in a liquid ejection apparatus having the same configuration as the liquid ejection apparatus 100 (FIG. 1) described in the first embodiment. However, the liquid ejection device according to the third embodiment is different in that a liquid FL having properties described later is used. The discharge preparation process of the third embodiment is substantially the same as the discharge preparation process of the first embodiment (FIGS. 2, 3A to 3D) except that the steps α and β are added.

  In the liquid ejection apparatus according to the third embodiment, the liquid FL ejected by the ejection unit 10 is a liquid having a property that the viscosity is lowered by application of a shearing force. As the liquid FL of the third embodiment, for example, a non-Newtonian fluid can be used. More specifically, a Bingham fluid or a pseudoplastic fluid can be used.

  In the discharge preparation process of the third embodiment, as described in the first embodiment, first, in the storage chamber filling process P1, the storage chamber filling steps a and b are the same as described in the first embodiment. Is executed (FIGS. 3A and 3B). Then, in the discharge port filling process P2, the pressure adjustment process is executed in the pressure adjustment step c in the same manner as described in the first embodiment.

  In the discharge port filling process P2 of the third embodiment, after the process c, in the process α, the execution of the viscosity reducing process for reducing the viscosity of the liquid FL is started. In the viscosity reduction process, the control unit 101 applies a shearing force to the liquid FL in the storage chamber 12 by the movement of the moving body 20 to reduce the viscosity of the liquid FL. The control unit 101 applies a voltage that repeatedly increases and decreases in a short cycle to the drive unit 30 to slightly vibrate the moving body 20 and applies a shearing force to the liquid FL.

  After the movement of the moving body 20 is started, the discharge port 15 is opened in step d (FIG. 3C). Due to the movement of the moving body 20, the viscosity of the liquid FL in the storage chamber 12 decreases, so that the flow rate of the liquid FL into the discharge port 15 is increased. In step e, after waiting for the discharge port 15 to be filled with a prescribed amount of liquid FL, in step β, the movement of the moving body 20 is stopped and the liquid viscosity reduction process is terminated.

  As described above, according to the liquid ejection device of the third embodiment and the liquid FL filling method executed in the ejection preparation process, the viscosity of the liquid FL is temporarily reduced by the movement of the moving body 20. The filling of the liquid FL into the discharge port 15 is speeded up. In addition, according to the liquid ejection device of the third embodiment and the method of filling the liquid FL executed in the ejection preparation process, various functions and effects similar to those described in the first embodiment can be achieved.

D. Fourth embodiment:
FIG. 7 is an explanatory diagram showing a flow of the discharge preparation process in the fourth embodiment. The ejection preparation process of the fourth embodiment is executed in a liquid ejection apparatus having the same configuration as the liquid ejection apparatus described in the third embodiment. The discharge preparation process of the fourth embodiment is the same as that described in the third embodiment except that steps α and β are added (FIGS. 4, 3A to 3D). 3D, which is almost the same as FIG. According to the liquid discharge device of the fourth embodiment and the method of filling the liquid FL executed in the discharge preparation process, the discharge of the liquid FL into the discharge port 15 is accelerated as described in the third embodiment. Is done. In addition, according to the liquid ejection device of the fourth embodiment and the liquid FL filling method executed in the ejection preparation process, various functions and effects similar to those described in the second embodiment can be achieved.

E. Variations:
The various configurations described in the above embodiments can be modified as follows, for example. Any of the modifications described below is positioned as an example of an embodiment for carrying out the invention.

E1. Modification 1:
In each of the above embodiments, the moving direction of the moving body 20 is the direction along the central axis CX and the vertical direction, and the central axis NX of the discharge port 15. On the other hand, the moving direction of the moving body 20 is not limited to the direction along the central axis CX or the vertical direction. The moving direction of the moving body may be a direction that intersects the vertical direction or a direction that intersects the central axis CX. Similarly, the moving direction of the moving body 20 may not be a direction along the central axis NX of the discharge port 15 but may be a direction intersecting the central axis NX of the discharge port 15. Further, the discharge direction of the liquid FL of the liquid discharge device may not be a direction along the gravity direction, but may be a direction intersecting the gravity direction.

E2. Modification 2:
In each of the embodiments described above, the drive unit 30 moves the moving body 20 by expansion and contraction of the piezoelectric element. On the other hand, the drive unit 30 may move the moving body 20 by means other than expansion / contraction deformation of the piezoelectric element. The drive unit 30 may move the moving body by, for example, a solenoid or gas pressure.
E3. Modification 3:
In each said embodiment, the flow volume adjustment part 58 of the outflow part 55 is comprised by the suction pump. On the other hand, the flow rate adjusting unit 58 may be configured by a valve such as a regulator or a pressure regulating valve instead of the suction pump. The flow rate adjusting unit 58 may be configured by combining a suction pump with a valve such as a regulator or a pressure regulating valve.

E4. Modification 4:
In each of the above-described embodiments, the outflow portion 55 circulates the liquid FL that has flowed out from the storage chamber 12 to the discharge flow path 18 via the outflow port 18 o to the supply portion 50. On the other hand, the outflow part 55 does not have to circulate the liquid FL to the supply part 50. For example, the outflow portion 55 may discharge the liquid FL flowing out from the storage chamber 12 to the discharge flow path 18 to the outside of the liquid ejection device, or may circulate directly to the storage chamber 12.

E5. Modification 5:
The liquid ejection device according to each of the above embodiments is configured as a 3D printer that ejects the liquid FL to form a three-dimensional object. On the other hand, the liquid ejection device may be configured as, for example, an ink jet printer that ejects ink to form an image. In this case, the ink as the liquid FL is ejected using the printing medium or the recording medium as the target object instead of the modeling stage 60. In addition, the liquid ejection device may be configured as an adhesive material application device that ejects and applies a liquid adhesive material.

E6. Modification 6:
In the above embodiment, some or all of the functions and processes realized by software may be realized by hardware. In addition, some or all of the functions and processes realized by hardware may be realized by software. As the hardware, for example, various circuits such as an integrated circuit, a discrete circuit, or a circuit module combining these circuits can be used.

  The present invention is not limited to the above-described embodiments, examples, and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the above effects, replacement or combination can be performed as appropriate. In addition, the technical features are not limited to those described as not essential in the present specification. If the technical features are not described as essential in the specification, they may be deleted as appropriate. Is possible.

DESCRIPTION OF SYMBOLS 10 ... Discharge part, 11 ... Head main-body part, 11b ... Bottom surface, 12 ... Storage chamber, 12w ... Side wall surface, 14 ... Drive room, 15 ... Discharge port, 16 ... Expansion opening, 17 ... Supply flow path, 17o ... Flow Inlet, 18 ... discharge channel, 18o ... outflow port, 19 ... sealing member, 20 ... moving body, 21 ... tip, 30 ... drive unit, 31 ... piezoelectric element, 32 ... drive circuit, 50 ... supply unit, 51 ... Piping, 52 ... Liquid reservoir, 53 ... Pressure generator, 55 ... Outlet, 57 ... Piping, 58 ... Flow rate adjusting unit, 60 ... Modeling stage, 65 ... Moving mechanism, 70 ... Energy applying unit, 100 ... Liquid ejecting device 101: Control unit, CX: Center axis, FL: Liquid, NX ... Center axis

Claims (5)

A storage chamber for storing a liquid; an outlet for discharging the liquid from the storage chamber; an inlet for allowing the liquid to flow into the storage chamber; and an outlet for allowing the liquid to flow out of the storage chamber. In a liquid discharge apparatus comprising: a storage chamber having a storage chamber; and a moving body that moves toward the discharge port in the storage chamber and discharges the liquid from the discharge port, discharge processing that discharges the liquid from the discharge port A method of filling the storage chamber and the discharge port with the liquid before
A storage chamber filling step of filling the storage chamber with the liquid by causing the liquid to flow from the inflow port after moving the moving body toward the discharge port and closing the discharge port with the mobile body. When,
A discharge port filling step of separating the moving body from the discharge port, opening the discharge port, and allowing the liquid to flow into the discharge port;
With
In the discharge port filling step, when the discharge port is opened, inflow of the liquid from the inflow port and outflow of the liquid from the outflow port so that the liquid flows into the discharge port, A pressure control step of controlling the pressure in the storage chamber by controlling at least one of the methods. The method of claim 1, comprising:
When the pressure of the liquid in the storage chamber is Pc, the atmospheric pressure outside the storage chamber is Po, and the meniscus pressure resistance of the liquid at the discharge port is Pm,
The pressure control step is a method of controlling the pressure in the storage chamber so as to satisfy a relationship of Po−Pm <Pc <Po + Pm. The method of claim 1 or claim 2, further comprising:
A method comprising: a blocking step of closing the discharge port by the moving body and blocking the inflow of the liquid into the discharge port after starting the discharge port filling step. A method according to any one of claims 1 to 3, comprising
The liquid has a property that the viscosity is lowered by application of a shearing force,
The discharge port filling step includes a step of reducing the viscosity of the liquid by applying the shearing force to the liquid in the storage chamber by the movement of the moving body. A liquid discharge apparatus that executes discharge processing for discharging liquid from a discharge port,
A storage chamber for storing the liquid and having the discharge port;
A supply section for allowing the liquid to flow into the storage chamber;
An outflow part for allowing the liquid to flow out of the storage chamber;
A moving body that moves toward the discharge port in the storage chamber and performs a discharge operation of discharging the liquid from the discharge port and a closing operation of closing the discharge port;
A controller that controls the supply of the liquid to the storage chamber by the supply unit, the outflow of the liquid from the storage chamber by the outflow unit, and the movement of the moving body;
With
Prior to the execution of the ejection process, the control unit fills the storage chamber and the ejection port with the liquid,
A storage chamber filling process in which the liquid is caused to flow into the storage chamber in which the discharge port is closed by the moving body, and the storage chamber is filled with the liquid;
In the storage chamber filled with the liquid, a discharge port filling process for opening the discharge port by separating the moving body from the discharge port and allowing the liquid to flow into the discharge port;
Run
The discharge port filling process includes the pressure of the liquid flowing into the storage chamber and the pressure of the liquid flowing out of the storage chamber so that the liquid flows into the discharge port when the discharge port is opened. A liquid ejecting apparatus including a pressure adjustment process for controlling the pressure in the storage chamber by controlling at least one of them.

Images