JP2018051432A - Droplet discharge device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new adhesion coping method in precise consideration of an element having an influence on discharge of a flowable material in the periphery of an opening of a discharge port.SOLUTION: An adhesion thickness and an adhesion spread of a flowable material are detected, which adheres onto the periphery of an opening of a storage part having a discharge port for discharging the flowable material therefrom. On the other hand, an adhesion thickness threshold and an adhesion spread threshold having an influence on discharge of the flowable material from the discharge port are stored correlatively with a viscosity of the flowable material. When a detected adhesion thickness and a detected adhesion spread both exceeds the adhesion thickness threshold and the adhesion spread threshold having an influence on discharge of the flowable material from the discharge port, reciprocation of a movable body is stopped.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a droplet discharge device.

  Conventionally, various droplet discharge devices for discharging a fluid material as droplets from a discharge port have been proposed. In such a droplet discharge device, in the discharge portion of the flowable material, by reciprocating the plunger rod that is a valve body, an inertial force is applied to the liquid in the discharge portion, and the flowable material is discharged from the nozzle that is the discharge port. Are discharged as droplets. The entire amount of the fluid material pushed by the plunger rod is not always discharged, and since it has fluidity, some fluid material may remain attached around the opening of the discharge port. Such adhesion of the flowable material may adversely affect the next discharge of the flowable material. Therefore, an adhesion countermeasure method that performs nozzle cleaning is proposed, because the spread of the flowable material adhering to the periphery of the opening of the discharge port is detected, and if the detected adhesion spread exceeds the threshold value, the quality may deteriorate due to liquid adhesion. (For example, Patent Document 1).

JP 2013-188737 A

  By the way, even if the degree of adhesion spread of the fluid material adhering to the periphery of the opening of the discharge port is the same, how the fluid material adhering rises is not uniform. Moreover, not only the degree of adhesion spreading of the attached fluid material, but also the way in which the attached fluid material swells may be affected by the viscosity of the fluid material. Then, even if the detected adhesion spread exceeds the threshold, depending on the viscosity of the flowable material and how the flowable material swells, there is no significant deterioration in quality due to liquid adhesion, or the next discharge of the flowable material. In addition, there is a possibility that a problem that the specified amount cannot be discharged or the discharge itself cannot be performed does not occur. For these reasons, there has been a demand for a new adhesion countermeasure method that accurately considers factors that affect the discharge of the fluid material around the opening of the discharge port.

  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 an aspect of the present invention, a droplet discharge device is provided. The droplet discharge device is a droplet discharge device that discharges a flowable material as droplets, the storage portion storing the flowable material and having a discharge port for discharging the flowable material, and the storage portion The movable body is reciprocally movable with respect to the discharge port in the interior thereof, and moves in a direction toward the discharge port to control the reciprocation of the movable body. A control unit, an adhesion detection unit that detects the adhesion thickness and adhesion spread of the flowable material adhering to the periphery of the opening of the discharge port as a detection adhesion thickness and detection adhesion spread, and is accommodated in and discharged from the accommodation unit. A viscosity input section that receives the input of the viscosity of the flowable material and uses the input viscosity as the input viscosity of the flowable material; and a threshold value of adhesion thickness and adhesion for comparison with the detected adhesion thickness and the detected adhesion spread Spread threshold The flowable material is attached to the periphery of the opening of the discharge port, and is regarded as a threshold that affects the discharge of the flowable material from the discharge port, and corresponds to the first viscosity of the flowable material. And a storage unit that stores a second viscosity higher than the first viscosity as a lower threshold than the adhesion thickness threshold and the adhesion spread threshold in the first viscosity. The control unit refers to the adhesion thickness threshold value and the adhesion spread threshold value for each viscosity of the flowable material stored in the storage unit, and the detected adhesion thickness and the detected adhesion spread correspond to the input viscosity. When both the adhesion thickness threshold and the adhesion spread threshold are exceeded, the reciprocation of the moving body is stopped.

  In this form of the droplet discharge device, the flowable material adhering to the periphery of the opening of the discharge port (hereinafter referred to as the adhering flowable material) is used in the case where the flowable material adheres to the periphery of the opening of the discharge port. In addition to the adhesion spread, the adhesion thickness of the adherent fluid material and the viscosity of the fluid material discharged from the ejection port are considered. The droplet discharge device of this form stops the reciprocating motion of the moving body when the adhesion thickness and adhesion spread of the adherent fluid material exceed both the adhesion thickness threshold and the adhesion spread threshold corresponding to the input viscosity of the fluid material. . The adhesion thickness threshold value and the adhesion spread threshold value for stopping the reciprocation of the moving body in this way are threshold values that affect the discharge of the fluid material from the discharge port when the fluid material adheres around the opening of the discharge port. Therefore, the droplet discharge device of this embodiment enables discharge of the fluid material by the reciprocating motion of the moving body until the adhesion thickness and adhesion spread of the adhesion fluid material reach the adhesion thickness threshold value and the adhesion spread threshold value. In the situation where the adhesion thickness and the adhesion spread of the adhesion fluid material do not reach the adhesion thickness threshold and the adhesion spread threshold, even if the adhesion fluid material exists around the opening of the discharge port, the next fluid material When discharging, a specified amount can be discharged. As a result, according to the droplet discharge device of this aspect, in addition to the adhesion spread of the adherence fluid material around the opening of the ejection port, the viscosity and the adhesion thickness of the fluid material are taken into consideration, thereby It is possible to favorably cope with the adhesion of the fluid material.

(2) In the droplet discharge device according to the above aspect, the adhesion thickness detection unit optically detects the adhesion thickness of the fluid material from a side of the housing unit, and the adhesion spread of the fluid material is detected. May be detected optically from the direction toward the discharge port. In this way, the adhesion thickness and adhesion spread of the adhesion fluid material can be detected simply and accurately.

(3) In any one of the above-described liquid droplet ejection apparatuses, the liquid droplet ejection apparatus includes a cleaning mechanism that is movable relative to the container and removes the fluid material that has adhered to the periphery of the opening of the ejection port. The cleaning mechanism may remove the fluid material while the reciprocating motion of the moving body is stopped by the control unit. If it carries out like this, removal of adhesion fluid material can be aimed at as adhesion countermeasure of fluid material in the opening periphery of an outlet.

  A plurality of constituent elements of each embodiment of the present invention described above are not essential, 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 component, and partially delete the limited contents of some of the plurality of components. In order to solve some or all of the above-described problems or achieve some 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 be realized in various modes. For example, a method for controlling a droplet discharge device, a method for discharging a droplet, a three-dimensional object formation device, a three-dimensional object formation method, an image forming apparatus, An image forming method, a printing apparatus, a printing method, a control method for each of the above-described apparatuses, a computer program that realizes each of the above-described methods and control methods, and a non-temporary recording medium on which the computer program is recorded can be realized. it can.

It is the schematic which shows the structure of the droplet discharge apparatus in embodiment of this invention. It is explanatory drawing which shows roughly the mode of the droplet imaging in the opening periphery of the discharge outlet by a 1st imaging part and a 2nd imaging part. It is a graph which shows the correspondence of an adhesion thickness threshold value (adhesion thickness) and an adhesion spread threshold value (adhesion area) for every viscosity of the liquid discharged. It is a flowchart which shows the determination control of the droplet discharge possibility by a control part.

  FIG. 1 is a schematic diagram showing a configuration of a droplet discharge apparatus 100A according to an embodiment of the present invention. FIG. 1 shows an arrow G indicating the direction of gravity (vertical direction) when the droplet discharge device 100A is arranged in a normal use state. In the present specification, “upper” or “lower” means a direction based on the vertical direction. The arrow G is also illustrated in FIG.

  The droplet discharge device 100A of this embodiment is a so-called 3D printer, and discharges the liquid LM, which is a fluid material, as droplets from the discharge unit 110 toward the modeling stage 150. “Droplet” refers to the state of the liquid ejected from the liquid ejecting apparatus, and includes those that have tails in the form of particles, tears, and threads. A specific example of the liquid LM will be described later.

  The droplet discharge device 100A forms a three-dimensional object by stacking layers obtained by solidifying the liquid LM on the modeling stage 150. In the present embodiment, the modeling stage 150, which is a droplet landing target for modeling a three-dimensional object, is a processing target to which droplets are attached for modeling a three-dimensional object. In addition to the ejection unit 110 and the modeling stage 150, the droplet ejection apparatus 100A includes a control unit 101, a supply unit 130, a moving mechanism 155, an energy application unit 160, a first imaging unit 170, and a second imaging unit. 180 and a cleaning mechanism 190.

  The control unit 101 controls the overall operation of the droplet discharge device 100A including the reciprocation of the valve body 113 described later. The control unit 101 includes a microcomputer including at least a CPU 102 and a memory 103 serving as a storage unit. The CPU 102 exhibits various functions by reading and executing a program stored in the memory 103. This program may be recorded on various recording media such as a hard disk, a flash memory, and a DVD-ROM.

  A computer 200 is connected to the control unit 101. The control unit 101 receives data MD for modeling a three-dimensional object from the computer 200. The data MD includes data representing the discharge position of the liquid LM in each layer stacked in the height direction of the three-dimensional object. Based on the data MD, the control unit 101 determines processing conditions such as the timing at which the liquid droplets of the liquid LM are discharged to the discharge unit 110 and the landing positions of the liquid droplets on the modeling stage 150. The computer 200 outputs the viscosity of the liquid LM discharged from the discharge unit 110 as a droplet to the control unit 101 by a user operation. Therefore, the control unit 101 constructs a viscosity input unit that receives an input of the viscosity of the liquid LM that is a flowable material supplied to the storage chamber 121 described later, by the CPU 102 executing a program stored in the memory 103. The control unit 101 may acquire the data MD directly not via the computer 200 but via a network or a recording medium.

  The discharge unit 110 is a so-called head unit, and discharges the liquid LM under the control of the control unit 101. The discharge unit 110 includes a main body 111 that is a hollow container and a discharge mechanism 112 for discharging the liquid LM. The main body 111 is made of stainless steel, for example. The discharge mechanism 112 is accommodated in the main body 111. The discharge mechanism 112 includes a valve body 113 and a drive unit 114. The drive unit 114 includes a piezo element 115 that is a piezoelectric element, and an urging member 116.

  The internal space of the main body 111 is divided into a storage chamber 121 and a drive chamber 125 by a partition wall 111s. The storage chamber 121 is located at the lower end of the main body 111, and the drive chamber 125 is located thereon. The storage chamber 121 stores the liquid LM. An inflow port 122 for allowing the liquid LM supplied from the supply unit 130 to flow in is provided as a through hole that opens in the horizontal direction in the side wall of the storage chamber 121.

  The bottom surface 121b of the storage chamber 121 forms a tapered inclined wall surface that is recessed toward the center thereof, and the discharge port 123 that is a nozzle for discharging the liquid LM to the outside is provided at the lowest portion in the center. Is provided. And the discharge part 110 which has the storage chamber 121 has the discharge port 123 which receives supply of the liquid LM in the storage chamber 121, stores the supplied liquid LM, and discharges the stored liquid LM, It functions as an accommodating portion in the present application. In the present embodiment, the discharge port 123 is formed as a through hole that penetrates the bottom wall portion of the main body 111 in the direction of gravity. The discharge port 123 is formed as a through hole that opens toward a vertically lower region on the bottom surface 111 b of the main body 111. In the present embodiment, the ejection direction, which is the direction in which the liquid LM is ejected from the ejection port 123, coincides with the opening direction of the ejection port 123 and coincides with the central axis NX in the vertical direction. The opening diameter of the discharge port 123 may be about 5 to 300 μm, for example.

  The valve body 113 of the discharge mechanism 112 opens and closes the discharge port 123. In the present embodiment, the valve body 113 is constituted by a metal columnar member. The tip 113t at the lower end of the valve body 113 has a hemispherical shape. The valve body 113 is disposed across the accommodation chamber 121 and the drive chamber 125 via a through hole 111h provided in the partition wall 111s. The valve body 113 is disposed so as to reciprocate in the longitudinal direction along the vertical direction on the central axis NX of the discharge port 123. That is, the valve body 113 functions as a movable body that can reciprocate with respect to the discharge port 123 inside the storage chamber 121. In addition, an annular seal member SL for suppressing leakage of the liquid LM to the drive chamber 125 is disposed in the through hole 111h so as to surround the periphery of the valve body 113.

  The drive chamber 125 accommodates a piezo element 115 and a biasing member 116 that constitute the drive unit 114 of the discharge mechanism 112. The driving unit 114 generates a driving force for reciprocating the valve body 113 in the accommodation chamber 121. The piezoelectric element 115 has a configuration in which a plurality of piezoelectric materials are stacked, and the length changes in the stacking direction by applying a voltage to each piezoelectric material. The upper end portion of the piezo element 115 is fixed to the upper wall surface of the drive chamber 125, and the lower end portion is in contact with the upper end portion of the valve body 113. When the piezo element 115 extends, the valve body 113 moves in a direction toward the discharge port 123. The urging member 116 is constituted by, for example, a string spring, and urges the valve body 113 upward. When the piezo element 115 contracts, the valve body 113 moves upward following the lower end portion of the piezo element 115 by the urging force of the urging member 116.

  In the state in which the piezo element 115 is extended and becomes the longest, the tip 113t of the valve body 113 is in line contact with the inclined wall surface of the peripheral edge of the discharge port 123 in an airtight manner to close the discharge port 123. The valve body 113 that drives to close the discharge port 123 in this manner discharges the liquid LM from the discharge port 123 in the process of moving in the direction toward the discharge port 123. When the piezo element 115 contracts, the valve body 113 moves upward following the lower end portion of the piezo element 115 by the urging force of the urging member 116, and the tip end portion 113 t is separated from the discharge port 123. In this manner, the discharge port 123 is opened and closed by the valve body 113 reciprocating between the position where the discharge port 123 is blocked and the position where it is separated from the discharge port 123.

  The supply unit 130 pumps the liquid LM into the storage chamber 121 of the discharge unit 110. The supply unit 130 includes a flow path member 131, a pipe 132, a valve 133, a liquid storage unit 134, and a pressure generation unit 135. The flow path member 131 is a member connected to the side surface of the main body 111. The flow path member 131 has a supply flow path 131p through which the liquid LM flows. In the present embodiment, the supply flow path 131p is configured as a tubular communication path having a portion extending obliquely downward from above the accommodation chamber 121. The supply channel 131p has one open end connected to the inlet 122 of the storage chamber 121 and the other open end connected to the pipe 132.

  The valve 133 is provided in the pipe 132 and controls the flow of the liquid LM to the supply flow path 131p. In the present embodiment, the valve 133 is constituted by a shutoff valve. When the valve 133 is open, the flow of the liquid LM to the supply flow path 131p is allowed, and when the valve 133 is closed, the flow of the liquid LM to the supply flow path 131p is blocked. The opening / closing operation of the valve 133 is controlled by the control unit 101. The valve 133 normally remains open during the operation of the droplet discharge device 100A.

  A liquid reservoir 134 is connected to the pipe 132. The liquid storage unit 134 is configured by a tank that stores the liquid LM, and functions as a supply source of the liquid LM in the droplet discharge device 100A. A stirring mechanism for stirring the liquid LM may be provided inside the tank. In the liquid storage unit 134, the liquid LM is mixed and adjusted so as to have the viscosity (input viscosity) of the liquid LM input from the user via the computer 200. In the present embodiment, under the control of the control unit 101, the viscosity of the liquid LM is adjusted to be, for example, an input viscosity of 1000 mPa · s or more.

  The pressure generating unit 135 is configured by a pressurizing pump, for example. The pressure generation unit 135 applies pressure to the liquid LM in the liquid storage unit 134 in order to flow into the storage chamber 121 via the pipe 132 and the supply channel 131p. For example, the pressure generation unit 135 applies a pressure of about 10 to 100 atm to the liquid LM. In FIG. 1, the pressure generator 135 is provided on the upstream side of the liquid reservoir 134, but the pressure generator 135 may be provided between the liquid reservoir 134 and the valve 133.

  The control unit 101 controls the pressure of the liquid LM in the storage chamber 121 by controlling the pressure applied to the liquid LM by the pressure generation unit 135. More specifically, the control unit 101 monitors the pressure of the liquid LM in the discharge unit 110 by a pressure gauge (not shown), and feedback-controls the pressure that the pressure generation unit 135 applies to the liquid LM.

  In the droplet discharge device 100A, the discharge of the liquid LM from the discharge unit 110 is executed as follows. Before the liquid LM is discharged, the piezo element 115 is extended and the valve body 113 closes the discharge port 123. In addition, a predetermined pressure is generated in the storage chamber 121 by the liquid LM being pumped by the supply unit 130.

  When starting the discharge of the liquid LM, first, the piezo element 115 is contracted and the valve body 113 is moved upward to be separated from the discharge port 123. Then, the liquid LM flows into a region between the valve body 113 and the discharge port 123 in the storage chamber 121 using the pressure applied to the liquid LM as a driving force.

  After the piezo element 115 is kept contracted for a predetermined period, the piezo element 115 is extended and deformed, and the valve body 113 is moved toward the discharge port 123. As a result, the liquid LM that has flowed into the region between the valve body 113 and the discharge port 123 is pushed out through the discharge port 123, and the liquid LM hangs downward from the discharge port 123. When the discharge port 123 is completely closed by the valve body 113, the discharge of the liquid LM from the discharge port 123 is blocked, and the liquid LM suspended from the discharge port 123 is discharged downward as a droplet.

  The flow rate of the liquid LM flowing out from the discharge port 123 is adjusted by the pressure applied to the storage chamber 121 by the pressure generator 135. The flow rate of the liquid LM is desirably determined in consideration of the viscosity of the liquid LM. The flow rate of the liquid LM discharged from the discharge port 123 may be adjusted to, for example, about 10 m / second to 20 m / second.

  The modeling stage 150 described above is provided at the tip of the discharge port 123 in the opening direction. The modeling stage 150 is configured by a flat plate-like member extending horizontally. The modeling stage 150 is arrange | positioned in the position which left | separated about 1.5-3 mm vertically downward from the discharge outlet 123, for example. In the droplet discharge device 100A of the present embodiment, the position of the modeling stage 150 relative to the discharge port 123 of the discharge unit 110 is displaced by the moving mechanism 155.

  The moving mechanism 155 includes a motor, a roller, a shaft, various actuators, and the like for moving the modeling stage 150. The moving mechanism 155 displaces the modeling stage 150 in the horizontal direction and the vertical direction relative to the discharge unit 110 as indicated by the double arrows X and Y shown in FIG. Thereby, the landing position of the liquid LM on the modeling stage 150 is adjusted. The control unit 101 controls the movement of the modeling stage 150 by the moving mechanism 155 based on the data MD for modeling the above-described three-dimensional object. In the droplet discharge device 100 </ b> A, the modeling stage 150 may be fixed and the discharge unit 110 may be displaced with respect to the modeling stage 150.

  The energy applying unit 160 applies energy to the droplets of the liquid LM that have landed on the modeling stage 150 and cures them. In this embodiment, the energy provision part 160 is comprised with a laser apparatus, and provides optical energy to a droplet by laser irradiation. The energy applying unit 160 includes at least a laser light source, a condensing lens for condensing the laser emitted from the laser light source onto a droplet landed on the modeling stage 150, and a galvanometer mirror for scanning the laser. Included (not shown). The energy applying unit 160 scans the landing position of the droplet on the modeling stage 150 with a laser, and sinters the material powder in the droplet with the optical energy of the laser. Alternatively, the material powder in the droplets is once melted and then solidified. Thereby, the solid object to be modeled and the particles constituting the support part for supporting the three-dimensional object are fixed on the modeling stage 150. In addition to the laser device, the energy applying unit 160 irradiates ultraviolet rays if it applies thermal energy to the droplets by irradiation with infrared light or discharges a liquid LM containing a powder and a solvent that is cured by ultraviolet rays. The liquid droplets of the liquid LM that has been used may be irradiated.

  The first imaging unit 170 incorporates an imaging device including a CCD (Charge Coupled Device), and is disposed on the side of the ejection unit 110. The first imaging unit 170 outputs a captured image obtained by capturing the periphery of the opening of the discharge port 123 from the side of the storage chamber 121 in the discharge unit 110 to the control unit 101.

  The second imaging unit 180 incorporates an imaging device equipped with a CCD, and is disposed in a non-modeling unit in the modeling stage 150. The second imaging unit 180 is a non-modeling period of the three-dimensional object by discharging the liquid LM as a droplet, for example, at the time of changing the setting of the three-dimensional object, or idling for checking the modeling quality after a predetermined number of lots are formed. In FIG. 5, the position of the modeling stage 150 is directly below the discharge port 123. In this state, the second imaging unit 180 is directed from the lower side of the storage chamber 121 in the ejection unit 110 toward the bottom surface 111b, so that the periphery of the opening of the ejection port 123 is imaged from the direction toward the ejection port 123. The captured image is output to the control unit 101. The analysis result of the captured image output from the first imaging unit 170 and the second imaging unit 180 and the input image performed by the control unit 101 will be described later. The imaging by the first imaging unit 170 may be performed during the non-modeling period of the three-dimensional object described above, or may be performed at all times for controlling the discharge amount of the liquid LM.

  The cleaning mechanism 190 includes a cleaning head 191, a drive mechanism 192, and a guide rail 193. The cleaning head 191 is installed between the discharge unit 110 and the modeling stage 150 by a guide rail 193 so as to be able to reciprocate horizontally as indicated by arrows in the drawing. The cleaning head 191 removes the liquid LM adhering to the vicinity of the opening of the discharge port 123 by reciprocating while a head formed of a nonwoven fabric or the like is in contact with the bottom surface 111 b of the discharge unit 110. Since the cleaning head 191 only needs to be movable relative to the discharge unit 110, the discharge unit 110 may be installed so as to be able to reciprocate horizontally as indicated by arrows in the drawing. The drive mechanism 192 controls the cleaning head 191 to reciprocate along the guide rail 193 by driving a drive source such as a pulse motor (not shown) under the control of the control unit 101. As shown in the drawing, the control unit 101 normally positions the cleaning head 191 at a position off the lower side of the discharge port 123 so as not to hinder the discharge of liquid droplets from the discharge port 123.

  With the above configuration, the droplet discharge device 100A of the present embodiment forms a three-dimensional object by discharging the liquid LM as droplets from the discharge unit 110 toward the modeling stage 150. The liquid LM used in the present embodiment is a fluid composition containing a powder and a solvent. The liquid material is, for example, a simple powder of magnesium (Mg), iron (Fe), cobalt (Co), chromium (Cr), aluminum (Al), titanium (Ti), copper (Cu), nickel (Ni), or A slurry containing a mixed powder of an alloy 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), a solvent, and a binder. It may be a mixed material in the form of a paste or paste. Alternatively, a resin obtained by melting a resin such as general-purpose engineering plastics such as polyamide, polyacetal, polycarbonate, modified polyphenylene ether, polybutylene terephthalate, and polyethylene terephthalate may be used. In addition, resins such as engineering plastics such as polysulfone, polyethersulfone, polyphenylene sulfide, polyarylate, polyimide, polyamideimide, polyetherimide, and polyetheretherketone may be used. Thus, the liquid material is not particularly limited, and metals other than the above metals, ceramics, resins, and the like can be used. The solvent of the liquid material 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 binder is, for example, an acrylic resin, an epoxy resin, a silicone resin, a cellulose resin or other synthetic resin, PLA (polylactic acid), PA (polyamide), PPS (polyphenylene sulfide) or other thermoplastic resin. Also good.

  FIG. 2 is an explanatory view schematically showing the state of droplet imaging around the opening of the discharge port 123 by the first imaging unit 170 and the second imaging unit 180. In the process of modeling a three-dimensional object by the droplet discharge device 100A of the present embodiment, the liquid LM discharged as droplets from the discharge unit 110 toward the modeling stage 150 is around the opening of the discharge port 123, more specifically, around the opening of the discharge port 123. May adhere to the surface of the bottom surface 111b. The adhesion of the liquid LM occurs under the influence of the viscosity of the liquid LM when moving upward of the valve body 113 due to the contraction of the piezo element 115, and forms a liquid film. Hereinafter, the liquid film-like liquid LM attached to the surface of the bottom surface 111b around the opening of the discharge port 123 is referred to as an attached liquid film LMz.

  The adhesion liquid film LMz is influenced by the viscosity of the liquid LM, and has an adhesion thickness (hereinafter referred to as adhesion thickness t) from the surface of the bottom surface 111b to the bottom surface of the liquid film, and the discharge port 123 as a center. The adhesion spread (hereinafter referred to as adhesion area s) on the surface of the bottom surface 111b is not necessarily constant, and remains on the surface of the bottom surface 111b by changing the adhesion thickness t or the adhesion area s. If the adhesion thickness t is small as shown in FIG. 2, the liquid LM can be discharged from the discharge port 123 after the next time. On the other hand, when the adhesion thickness t increases as shown in FIG. 2, it may hinder the discharge of the liquid LM from the discharge port 123 from the next time. That is, the adhesion thickness t is a factor that affects the discharge of the liquid LM from the discharge port 123 due to the liquid LM adhering around the opening of the discharge port 123. As described above, the first imaging unit 170 captures an image including the adhesion liquid film LMz around the opening of the ejection port 123 from the side of the storage chamber 121 in the ejection unit 110 and controls the captured image. Output to the unit 101. The control unit 101 performs image analysis on the input captured image, defines the adhesion thickness t based on the image analysis result, and thereby the adhesion thickness t is detected.

  The adhesion area s determines whether or not the liquid LM can be discharged from the discharge port 123 on and after the next time, in relation to the width and the adhesion thickness t. That is, even in the adhesion area s, the liquid LM adhered to the periphery of the opening of the discharge port 123 becomes a factor that affects the discharge of the liquid LM from the discharge port 123. As described above, the second imaging unit 180 images the periphery of the opening of the discharge port 123 from the lower side of the storage chamber 121 toward the bottom surface 111b, and outputs a captured image including the attached liquid film LMz to the control unit 101. To do. The control unit 101 performs image analysis on the input captured image, defines the above-described adhesion area s based on the image analysis result, and thereby the adhesion area s is detected. Accordingly, the first imaging unit 170, the second imaging unit 180, and the control unit 101 that performs image analysis, detect adhesion thickness (adhesion thickness t) and adhesion spread (adhesion area s) of the adhesion liquid film LMz. The part is composed. In addition, as shown in FIG. 2, the adhesion liquid film LMz does not spread concentrically with respect to the discharge port 123, but the outer shape thereof is irregular although it is substantially circular. Therefore, when detecting the adhesion area s by image analysis, in order to simplify the area calculation, the area of a circle whose diameter is the maximum value of the adhesion spread of the adhesion liquid film LMz is used as the adhesion area s, or the axis of the discharge port 123 For example, the adhesion area s may be an area of a circle whose diameter is the average value of adhesion spread obtained at a pitch of 90 °.

  As shown in FIG. 2, the adhesion thickness t and the adhesion area s in the adhesion liquid film LMz are narrowed when the adhesion thickness t is small, and the adhesion area s is wide when the adhesion thickness t is large. Absent. That is, the adhesion thickness t and the adhesion area s in the adhesion liquid film LMz can take various values. If the adhesion area s is smaller than the predetermined threshold when the adhesion thickness t is a predetermined threshold value, the adhesion liquid film LMz having the adhesion thickness t and the adhesion area s with such threshold values adheres to the periphery of the opening of the discharge port 123. Even if it does, discharge of the liquid LM from the discharge outlet 123 after the next time is attained. On the other hand, when both the adhesion thickness t and the adhesion area s exceed the threshold value, it may hinder the discharge of the liquid LM from the discharge port 123 after the next time. The above-mentioned threshold adhesion thickness t and adhesion area s can be grasped as an adhesion thickness threshold value and an adhesion spread threshold value that affect the ejection from the ejection port 123 by the adhesion liquid film LMz adhered around the opening of the ejection port 123. The correspondence between the thickness threshold value (adhesion thickness t) and the adhesion spread threshold value (adhesion area s) is defined by the viscosity of the liquid LM to be discharged. FIG. 3 is a graph showing the correspondence between the adhesion thickness threshold (adhesion thickness t) and the adhesion spread threshold (adhesion area s) for each viscosity of the liquid LM to be discharged. In the graph of FIG. 3, the horizontal axis represents the adhesion thickness t corresponding to the adhesion thickness threshold value, and the vertical axis represents the adhesion area s corresponding to the adhesion spread threshold value.

  The graph for each viscosity in FIG. 3 shows the threshold value of whether or not the liquid LM can be discharged from the discharge port 123 after the next time, and the adhesion thickness t detected using the first imaging unit 170 and the second imaging unit 180. And the adhesion area s. That is, if the adhesion thickness t and the adhesion area s of the adhesion liquid film LMz around the opening of the discharge port 123 belong to a region below the graph, the liquid LM can be discharged from the discharge port 123 on and after the next time. On the other hand, if the adhesion thickness t and the adhesion area s of the adhesion liquid film LMz around the opening of the discharge port 123 belong to the region above the graph, there is a problem in the discharge of the liquid LM from the discharge port 123 from the next time. I can get up. The control unit 101 uses the correspondence relationship between the adhesion thickness threshold value (adhesion thickness t) and the adhesion spread threshold value (adhesion area s) illustrated in FIG. 3 as a discharge propriety map for each viscosity of the liquid LM to be discharged from the discharge unit 110. It is stored in the memory 103. The memory 103 also stores a discharge propriety map for viscosities other than the three viscosities shown in FIG. FIG. 3 shows the correspondence between the adhesion thickness threshold (adhesion thickness t) and the adhesion spread threshold (adhesion area s) for three liquid LMs of 1200 mPa · s, 2800 mPa · s, and 5000 mPa · s. For viscosities of 2800 mPa · s and 5000 mPa · s (second viscosity) higher than the viscosity of s (first viscosity), the adhesion thickness threshold (adhesion thickness t) and adhesion spread threshold (adhesion area) at a viscosity of 1200 mPa · s The threshold is lower than that of s). For a viscosity of 5000 mPa · s (second viscosity) higher than the viscosity of 2800 mPa · s (first viscosity), the adhesion thickness threshold (adhesion thickness t) and the adhesion spread threshold (adhesion area) at a viscosity of 2800 mPa · s. The threshold is lower than that of s).

  FIG. 4 is a flowchart showing control for determining whether or not droplets can be discharged by the control unit 101. This droplet discharge possibility determination control is repeatedly executed by the control unit 101 (see FIG. 1) every predetermined time, and first, it is determined whether or not the present time is a timing for determining whether or not a droplet can be discharged (step S10). ). Normally, the droplet discharge device 100A repeatedly projects the liquid LM as droplets from the discharge unit 110 for modeling a three-dimensional object, and thus such a three-dimensional object modeling period is not the execution timing of the droplet discharge availability determination control. . In the droplet discharge device 100A of the present embodiment, since the execution timing of the droplet discharge possibility determination control is set at the time of changing the set-up or idling of the three-dimensional object, the change setup switch in the control unit 101 is set in step S10. (Not shown in the figure) and the operation status of the idling switch (not shown in the figure) are used to determine whether or not the current time is the timing for determining whether or not to allow droplet discharge. If it is determined in step S10 that the current time is not the timing for determining whether or not the liquid droplets can be discharged, the control unit 101 once ends this routine. It should be noted that the control for determining whether or not the liquid droplets can be discharged may be executed in response to the switch operation of the change setup switch or the idling switch.

  If it is determined in step S10 that the current time is the timing for determining whether or not droplets can be ejected, the control unit 101 reads the viscosity of the liquid LM input from the computer 200 (step S20). Note that, during idling for quality check, since the same three-dimensional object is formed using the same liquid LM as before, the viscosity reading of the liquid LM may be skipped.

  Following step S20, the controller 101 performs liquid film shape detection (step S30). As described with reference to FIG. 2, the liquid film shape detection in step S <b> 30 is performed based on the image analysis of the captured image including the attached liquid film LMz input from the first imaging unit 170 and the second imaging unit 180. From the image analysis result, the adhesion thickness t and the adhesion area s of the adhesion liquid film LMz are detected.

  When the adhesion thickness t and the adhesion area s of the adhesion liquid film LMz are detected in this way, the control unit 101 refers to a discharge propriety map corresponding to the graph of FIG. 3 corresponding to the viscosity of the liquid LM read in Step S20 (Step S20). S40) From the reference result, it is determined whether or not the adhesion thickness t and the adhesion area s detected by the adhesion liquid film LMz exceed the threshold shown in FIG. 3 (step S50). If it is determined in step S50 that the detected adhesion thickness t and adhesion area s do not exceed the threshold (discharge threshold) shown in FIG. 3, the control unit 101 once ends this routine.

  If it is determined in step S50 that the detected adhesion thickness t and adhesion area s exceed the threshold values shown in FIG. 3, the control unit 101 performs stop control so that the valve body 113 does not reciprocate (step S60). ). Thereafter, the control unit 101 performs cleaning using the cleaning mechanism 190 (step S70), and the attached liquid film LMz attached to the bottom surface 111b of the discharge unit 110 is removed by the cleaning head 191. And the control part 101 cancels | releases the stop of the valve body 113 after completion of cleaning, and complete | finishes this routine.

  The droplet discharge device 100A according to the present embodiment having the above-described configuration is configured to detect and attach the attached liquid film LMz in order to cope with the attached liquid film LMz attached to the bottom surface 111b around the opening of the discharge port 123. In addition to the spread (adhesion area s), the adhesion thickness t, which is the detected adhesion thickness of the adhesion liquid film LMz, and the viscosity of the liquid LM ejected from the ejection port 123 are considered. Then, in the droplet discharge device 100A of the present embodiment, the adhesion thickness t and the adhesion area shown in the graph of FIG. 3 in which the detected adhesion thickness t and adhesion area s of the adhesion liquid film LMz correspond to the input viscosity of the liquid LM. When the threshold value of s is exceeded (step S50: affirmative determination), the reciprocating motion of the valve body 113 is stopped (step S60). Therefore, until the detected adhesion thickness t and adhesion area s of the adhesion liquid film LMz reach the adhesion thickness threshold value and the adhesion spread threshold value, the fluid material can be discharged by the reciprocation of the valve body 113. Then, under the situation where the adhesion thickness and the adhesion area s of the adhesion liquid film LMz do not reach the threshold values of the adhesion thickness t and the adhesion area s shown in the graph of FIG. 3, the adhesion liquid film LMz is formed around the opening of the discharge port 123. Even if it exists, the specified amount can be discharged when the liquid LM is discharged next time. As a result, according to the droplet discharge device 100A of the present embodiment, in addition to the adhesion area s of the adhesion liquid film LMz around the opening of the discharge port 123, the viscosity of the liquid LM and the adhesion thickness t of the adhesion liquid film LMz are considered. By doing so, it is possible to cope with the adhesion of the liquid LM around the opening of the discharge port 123.

  The droplet discharge device 100A according to the present embodiment detects the adhesion thickness t of the adhesion liquid film LMz from the image analysis result of the captured image of the first imaging unit 170 that images the periphery of the opening of the ejection port 123 from the side. From the image analysis result of the second imaging unit 180 that images the periphery of the opening of the outlet 123 from below, the adhesion area s of the adhesion liquid film LMz is detected. Therefore, according to the droplet discharge device 100A of the present embodiment, the adhesion thickness t and the adhesion area s of the adhesion liquid film LMz can be detected easily and accurately.

  In a state where the valve body 113 is stopped (step S60), the droplet discharge device 100A of the present embodiment reciprocates along the guide rail 193 while bringing the cleaning head 191 into contact with the bottom surface 111b of the discharge unit 110. (Step S70), the liquid LM adhering to the periphery of the opening of the discharge port 123 is removed. Therefore, according to the droplet discharge device 100A of the present embodiment, the adhesion liquid film LMz can be removed as a countermeasure for the adhesion liquid film LMz adhering to the periphery of the opening of the discharge port 123.

  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. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

  In the embodiment described above, the adhesion thickness t and the adhesion area s of the adhesion liquid film LMz are detected from the image analysis of the captured images of the first imaging unit 170 and the second imaging unit 180 provided with the CCD. You may detect using the used optical apparatus. In this case, laser light may be irradiated from the side of the discharge unit 110, and the adhesion thickness t of the adhesion liquid film LMz may be detected from the detection result of the reflected light of the irradiated laser light. With respect to the adhesion area s of the adhesion liquid film LMz, the bottom surface 111b in the vicinity of the opening of the discharge port 123 is irradiated with laser light from the direction toward the discharge port 123, and from the detection result of the reflected light of the irradiated laser light, the adhesion liquid What is necessary is just to detect the adhesion area s of the film LMz. Detection errors due to laser light interference can be avoided by shifting the laser light irradiation timing of the optical device replacing the first imaging unit 170 and the optical device replacing the second imaging unit 180.

  In the embodiment described above, an image including the adhesion liquid film LMz is captured by the first imaging unit 170 fixed to the side of the ejection unit 110, but the first imaging unit 170 that can rotate around the axis of the ejection port 123. You may image. In this way, even if the adhesion thickness t of the adhesion liquid film LMz changes within the range of the adhesion spread, the adhesion liquid film LMz is included from each direction around the axis of the discharge port 123, for example, from the direction of an equal pitch of 90 °. An image can be taken. In this case, the average value or the maximum value of the adhesion thickness t obtained from the image analysis of the image obtained from each direction can be used as the adhesion thickness t of the adhesion liquid film LMz.

  In the embodiment described above, the adhesion thickness t and the adhesion area s of the adhesion liquid film LMz are detected from the image analysis of the captured images of the first imaging unit 170 and the second imaging unit 180 provided with the CCD. You may detect the adhesion thickness t and the adhesion area s by a change. For example, a capacitance displacement measuring device is installed on the side of the discharge unit 110 and the modeling stage 150. Since the discharge member 110 and the adhesion liquid film LMz naturally have different constituent materials, the electrostatic capacity of the bottom surface 111b of the discharge part 110 is different between the part of the adhesion liquid film LMz and the part without the adhesion liquid film LMz. To do. By detecting this difference in capacitance by the side of the discharge unit 110 and the capacitance displacement measuring device provided on the modeling stage 150, the adhesion thickness t and the adhesion area s can be detected.

  In the above-described embodiment, when taking measures for adhesion such as cleaning by the cleaning head 191, the threshold value of adhesion thickness (adhesion thickness threshold value) and the threshold value of adhesion area s (adhesion value) corresponding to the viscosity (input viscosity) of the liquid LM. Although the correspondence relationship with the spread threshold) is used, the volume of the attached liquid film LMz on the lower side of the bottom surface 111b in FIG. 2 is detected using an optical device or a capacitance type measurement device, and the viscosity (input) of the liquid LM is input. A threshold value may be set for the volume of the adhesion liquid film LMz corresponding to (viscosity), and an adhesion countermeasure such as cleaning with respect to the adhesion liquid film LMz may be achieved with the volume threshold value.

DESCRIPTION OF SYMBOLS 100A ... Droplet discharge apparatus, 101 ... Control part, 102 ... CPU, 103 ... Memory, 110 ... Discharge part, 111 ... Main body part, 111b ... Bottom face, 111h ... Through-hole, 111s ... Partition, 112 ... Discharge mechanism, 113 ... Valve body, 113t... Tip portion, 114... Driving portion, 115... Piezo element, 116 .. biasing member, 121. Supply unit 131... Channel member 131 p. Supply channel 132 132 Piping 133 Valve Valve 134 Liquid storage unit 135 Pressure generating unit 150 Modeling stage 155 Moving mechanism 160 Energy application unit , 170 ... 1st imaging part, 180 ... 2nd imaging part, 190 ... Cleaning mechanism, 191 ... Cleaning head, 192 ... Drive mechanism, 193 ... Guide rail, 2 0 ... Computer, LM ... liquid, LMZ ... adhered liquid film, MD ... data, SL ... sealing member, NX ... central axis

Claims (3)

A droplet discharge device for discharging a fluid material as droplets,
A container having a discharge port for containing the fluid material and discharging the fluid material;
A movable body that is capable of reciprocating with respect to the discharge port inside the accommodating portion, and that discharges the fluid material from the discharge port by moving in a direction toward the discharge port;
A control unit for controlling the reciprocation of the movable body;
An adhesion detector for detecting the adhesion thickness and adhesion spread of the fluid material adhered around the opening of the discharge port as a detection adhesion thickness and detection adhesion spread;
A viscosity input unit that receives an input of the viscosity of the flowable material that is stored and discharged in the storage unit, and the input viscosity of the flowable material is the received viscosity;
The adhesion thickness threshold value and the adhesion spread threshold value to be compared with the detected adhesion thickness and the detection adhesion spread affect the discharge of the flowable material from the discharge port by adhering the flowable material around the opening of the discharge port. Is stored in association with the first viscosity of the flowable material, and for the second viscosity higher than the first viscosity, the adhesion thickness threshold value at the first viscosity is stored. And a storage unit that stores a threshold value lower than the adhesion spread threshold value,
The control unit refers to the adhesion thickness threshold value and the adhesion spread threshold value for each viscosity of the flowable material stored in the storage unit, and the detected adhesion thickness and the detected adhesion spread correspond to the input viscosity. A droplet discharge device that stops the reciprocation of the moving body when both the thickness threshold and the adhesion spread threshold are exceeded. The adhesion detector
The thickness of the flowable material attached is optically detected from the side of the housing part,
The droplet discharge device according to claim 1, wherein the adhesion spread of the fluid material is optically detected from a direction toward the discharge port. The droplet discharge device according to claim 1 or 2,
A cleaning mechanism that is movable relative to the housing portion and removes the fluid material attached around the opening of the discharge port;
3. The droplet discharge device according to claim 1, wherein the cleaning mechanism removes the flowable material while the reciprocating motion of the moving body is stopped by the control unit.

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