KR20110030264A - Unit for injecting ink and ink jet marking machine having the unit - Google Patents

Abstract

PURPOSE: An ink spray unit and an inkjet marking device having the same are provided to prevent the ink in a nozzle from hardening by blocking the ink from making contact with the air. CONSTITUTION: An ink spray unit comprises a head(110), a head body(120), and a shutter(130). A nozzle is formed on the head to spray the ink to a target. The head body comprises a slit for passing the ink sprayed from the nozzle and supports the head. The shutter opens and closes the slit according to whether or not the ink is sprayed from the nozzle. The shutter is formed from an elastic material to make tight contact with the head body.

Description

Unit for injecting ink and ink jet marking machine having the unit

The present invention relates to an ink ejection unit and an inkjet marking apparatus having the same, and more particularly, to an ink ejection unit and an inkjet marking apparatus having the same to obtain an output by ejecting ink onto an object.

In general, an ink jet marking apparatus includes an ink jet unit for largely jetting ink to obtain an output, an ink supply unit for supplying ink to the ink jet unit, and a control unit for controlling the ink jet unit and the supply unit.

The ink jetting unit of the inkjet marking apparatus injects ink supplied from the ink supplying unit onto a target object through a nozzle according to a control signal of the controller. When the ejection of the ink is stopped at the nozzle of the ink ejection unit and the nozzle is exposed to the air, the ink of the solvent component contained in the ink is evaporated and a large number of nozzles are clogged.

If the nozzle is sprayed as described above is clogged, the ink is not sprayed properly to obtain the desired output. It is necessary to remove the solidified ink by using a cleaner hardened on the nozzle or by discharging a large amount of ink to the nozzle. Therefore, the work becomes cumbersome and the time for removing the solidified ink is consumed, which lowers the work efficiency.

The present invention includes an ink ejection unit for preventing ink from solidifying on a nozzle of a head for ejecting ink, and an automatic cleaning unit for easily solving nozzle clogging caused by ink solidification.

The present invention is to provide an inkjet marking apparatus having the ink ejection unit.

The ink ejection unit according to the present invention has a head having a nozzle for ejecting ink onto an object, an insertion groove into which the nozzle is inserted, and a slit communicating with the insertion groove and passing ink ejected from the nozzle, wherein the head And a shutter in contact with the head body for fixing and supporting the head body and opening and closing the slit according to whether ink is injected from the nozzle.

According to one embodiment of the present invention, the shutter may be made of an elastic material for close contact with the head body.

According to one embodiment of the present invention, the shutter may be made of an elastic material for close contact with the head body.

According to one embodiment of the present invention, the ink ejection unit may further include a driving unit connected to one end of the shutter and moving the shutter to open and close the shutter.

According to one embodiment of the invention, the drive unit may rotate the shutter reciprocating.

According to one embodiment of the present invention, the driving unit may linearly reciprocate the shutter.

According to one embodiment of the present invention, the ink ejection unit may further include an elastic member mounted to the driving unit and providing an elastic force to closely contact the head body with the shutter.

According to one embodiment of the present invention, the ink jet unit may be provided on one side of the head body, and may further include a sensing unit for checking whether the shutter is opened or closed.

According to one embodiment of the present invention, the sensing unit is mounted to the driving unit and a sensing member moving in accordance with the driving of the driving unit and mounted on one side of the head body, and includes a sensor for sensing the sensing member. Can be.

According to one embodiment of the invention, the sensing unit may include a sensor mounted on the head body for detecting the position of the shutter.

According to one embodiment of the present invention, the ink ejection unit may further include a processor connected to the head, the driving unit, and the sensing unit, and controlling the ink ejection of the head and opening / closing of the shutter.

According to one embodiment of the invention, the processor may further include an interlock unit for stopping the operation of the head when the shutter is not in operation.

According to one embodiment of the present invention, the head body includes a region in which the slit is formed on a surface in contact with the shutter to space the marking surface of the object and the cover, the direction parallel to the long direction of the slit It may have a groove extending to.

According to one embodiment of the present invention, the depth of the groove may be deeper than the thickness of the shutter to accommodate the shutter.

According to one embodiment of the present invention, the ink ejection unit may further include a cover having a second slit at a position corresponding to the slit and surrounding the head body.

According to one embodiment of the present invention, the cover may have a groove extending in a direction perpendicular to the long direction of the second slit, including a region in which the second slit is formed on a surface facing the object.

According to one embodiment of the present invention, surfaces of the head body and the shutter may be coated to reduce friction between the head body and the shutter and to improve chemical resistance of the head body and the shutter.

According to one embodiment of the invention, the coating is Teflon coating, ceramic coating, polyethylene (PE, PE) coating, molybdenum (MoS2) coating, PEEK (Polyether etherketone) coating (vicote coating), polyamide (Poly Amide) Coating, CONIF coating, Alucoat coating, polyphenylene sulfide (PPS) coating, polyacetal (POM) coating, urethane coating, nylon coating.

According to one embodiment of the present invention, the head body extends from the inner wall of the insertion groove to the surface into which the head is inserted, and may have a suction passage for sucking ink remaining in the nozzle.

According to one embodiment of the invention, the ink ejection unit has a suction line of S-shape to be repeated to prevent back flow of ink sucked through the suction passage, it is connected to the suction passage of the head body It may further comprise a suction block.

According to one embodiment of the invention, the material of the head body and the shutter may be any one of polyimide (Polyimide), polyether ether ketone (PEEK), stainless steel, elastic steel.

An ink jet marking apparatus according to the present invention includes an ink jet unit for jetting ink toward an object, an ink supply unit for supplying ink to the ink jet unit, and an ink suction unit for suctioning residual ink in the ink jet unit. And a control unit for controlling operations of the ink ejection unit, the ink supply unit, and the ink suction unit, wherein the ink ejection unit includes a head having a nozzle formed therein for ejecting the ink to an object, and the nozzle is inserted therein. And a slit communicating with the insertion groove and passing the ink injected from the nozzle, the head body for fixedly holding the head and the head body, and the slit in contact with the ink injection of the nozzle. It may include a shutter for opening and closing the.

The ink ejection unit according to the present invention seals the nozzle while the ink is not ejected to block contact with air, thereby preventing the ink from solidifying at the nozzle. In addition, the ink remaining in the nozzle and the ink injected for cleaning the nozzle are sucked to prevent the ink from solidifying in the nozzle.

The inkjet injection unit may check the opening and closing operation of the shutter by using a detection unit. Therefore, malfunction of the shutter can be confirmed quickly.

1 is a schematic configuration diagram of an inkjet marking apparatus according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view for explaining an ink ejection unit of the inkjet marking apparatus shown in FIG. 1.
3 is a side view for explaining a state in which the head, the head body and the suction block shown in FIG.
4 is a side view illustrating the shutter driver illustrated in FIG. 1.
5 is a side view for explaining opening and closing of the shutter shown in FIG. 1.
FIG. 6 is a schematic block diagram for explaining the ink supply unit and ink suction unit shown in FIG.
FIG. 7 is a schematic block diagram for describing the controller illustrated in FIG. 1.

Hereinafter, an ink ejection unit and an inkjet marking apparatus having the same according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. As the inventive concept allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. Like reference numerals are used for like elements in describing each drawing. In the accompanying drawings, the dimensions of the structures are shown in an enlarged scale than actual for clarity of the invention.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, action, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

1 is a schematic configuration diagram of an inkjet marking apparatus 1000 according to an exemplary embodiment of the present invention.

Referring to FIG. 1, the inkjet marking apparatus 1000 may include an ink ejection unit 100 for discharging ink and obtaining an output, and an ink supply unit 200 for supplying ink to the ink ejection unit 100. Controlling the ink ejection unit 300, the ink ejection unit 100, the ink supply unit 200, and the ink suction unit 300 to suck the remaining ink ejected from the ink ejection unit 100. It is composed of a control unit 400 for.

The ink ejection unit 100, the ink supply unit 200, the ink suction unit 300, and the control unit 400 are supported by the support unit 500. The support unit 500 includes a guide member extending in the horizontal direction.

The ink ejection unit 100 is provided to be movable in the horizontal direction along the guide member. The ink ejection unit 100 may be the same as the ink supply unit 200 or higher than the ink supply unit 200. The ink ejection unit 100 is mounted to the guide member and can be rotated at various angles.

A supply line for supplying ink is provided between the ink supply unit 200 and the ink ejection unit 100. A suction pipe for sucking ink is provided between the ink suction unit 300 and the ink injection unit 100. The control unit 400 is connected to the ink injection unit 100, the ink supply unit 200, and the ink suction unit 300 by a cable, respectively, and transmits a control signal. The control unit 400 includes a keypad 410 for inputting output contents and a display monitor 420 for displaying an input result through the keypad 410.

Various types of inks may be used in the inkjet marking apparatus 1000. The ink may be classified into an oil ink, an aqueous ink, an alcohol ink, a glycol ink, a resin ink, a wax ink, a polyamide ink, and a rubber base ink according to ink components. Oxidation polymerization ink, evaporation drying ink, penetration drying ink, precipitation drying ink, UV curing ink, infrared drying ink, natural drying ink, thermosetting ink, moisture depending on ink drying type It can be classified into a set ink, an electron beam curable ink, a one-liquid reactive ink, a two-liquid reactive ink, a gelling dry ink, a vapor curing ink, and a cold set ink. According to the ink components, oil based (solvent based) ink and water based ink are mainly used, and according to the ink drying type, ultraviolet curing ink which causes photochemical reaction with energy of ultraviolet rays and hardens from liquid phase to solid phase by second is mainly used. .

FIG. 2 is an exploded perspective view for explaining the ink ejection unit 100 of the inkjet marking apparatus 1000 illustrated in FIG. 1, and FIG. 3 is a head 110, a head body 120, and a suction block illustrated in FIG. 1. It is a side view for demonstrating the state in which 150 is couple | bonded. 4 is a side view for explaining the shutter driver 140 shown in FIG. 1, and FIG. 5 is a side view for explaining opening and closing of the shutter 130 shown in FIG. 1.

2 to 5, the head 110 of the ink ejection unit 100 has a rectangular bar shape having a rectangular cross section. The ink supply pipe 252 is connected to one end of the head 110 to supply ink to the head 110. The cable connection part 116 is formed at one end, and a cable 176 for electrical connection with the processor 170 to be described later is connected. The nozzle 112 is formed at the other end of the head 110 corresponding to the one end, and the ink, which is supplied through the ink supply pipe 252 according to the control signal of the control unit 400, Spray to object such as product.

In addition, the locking jaw 114 is the head 110 is formed along the outer periphery, has a predetermined width. A heating member (not shown) is attached to the outer surface of the head 110, and adjusts the viscosity of the ink inside the head 110 to facilitate the fluidity of the ink. In particular, when the viscosity of the ink is high, the heating member is mainly used.

The head 110 has an aluminum material that conducts heat well and is manufactured by die casting.

Injection methods of the nozzle 112 of the head 110 may include a valve inkjet, a continuous inkjet, a heating ink, a piezo ink jet, and the like.

The valve method is a method of ejecting ink using the opening and closing of the valve. In the circulation method, the ink is divided into fine droplets at regular intervals through the charge tunnel and is marked using the difference in the reaction height of the ink according to the intensity of the high voltage applied in the high-voltage tunnel. to be. The heating method generates instantaneous high heat in the ink, and in this case, sprays ink droplets generated by boiling of high heat. The piezo method is a method of discharging ink by the movement of the piezo by applying a high voltage to the piezo.

The head body 120 fixes and supports the head 110. For example, the head body 120 has a hexahedral block shape. The head body 120 has an insertion groove 122 on one surface. The size and shape of the insertion groove 122 corresponds to the size and shape of the portion of the nozzle 112 of the head 110. The head 110 is the other end is provided with the nozzle 112 is inserted into the insertion groove 122 is fixed to the head body 120. The head 110 is inserted until the locking jaw 114 is caught by the head body 120.

The head body 120 has a first slit 124 on the other surface opposite to one surface. The first slit 124 communicates with the insertion groove 122 and is positioned to correspond to the nozzle 112 of the head 110 inserted into the head body 120. The first slit 124 passes ink from the nozzle 112.

The head body 120 has a first groove 126 on the other surface. The first groove 126 is formed in a direction parallel to the long direction of the first slit 124 including a region in which the first slit 124 is formed. The first groove 124 may be formed to a depth greater than the thickness of the shutter 130 to be described later.

The head body 120 has a suction passage 128 extending from the inner wall of the insertion groove 122 to the one surface. The suction passage 128 is a first passage 128a formed on the inner wall of the insertion groove 112 and a second passage formed on one surface of the head body 120 to communicate with the first passage 128a. (128b).

The first passage 128a is located at a side portion of the nozzle 112 of the head 110 inserted into the head body 120. The width of the first passageway 128a may have a size between the longitudinal width of the nozzle 112 and the longitudinal width of the head 110.

The second passage 128b serves to reduce the width of the first passage 128a. The second passage 128b is connected to a suction block 150 to be described later.

Ink, dust, and other residues remaining in the nozzle 112 are sucked and discharged through the suction passage 128.

The head body 120 includes a material having excellent elasticity, chemical resistance, impact resistance, fatigue resistance, and the like. Examples of the material of the head body 120 may include polyimide, polyether ether ketone, stainless steel, and elastic steel.

Meanwhile, a sealing member (not shown) may be provided between the head 110 and the head body 120. Since the sealing member prevents air from penetrating through the head 110 and the head body 120, the phenomenon in which the nozzle 112 is exposed to air and solidifies can be reduced. Examples of the material of the sealing member include bonds such as epoxy, Teflon, UV-based, or the like, or adhesives or sheets having chemical resistance that are not damaged by ink.

The shutter 130 is provided on the other surface of the head body 120 in which the first groove 126 is formed, and rotates reciprocally in a direction parallel to the other surface of the head body 120. The shutter 130 opens and closes the first slit 124 through the rotary reciprocating motion. The shutter 130 has a thin plate shape. The shutter 130 is made of an elastic material and can prevent the shutter 130 from being deformed by an external force. The material of the shutter 130 may be polyimide, polyether ether ketone, PEEK, stainless steel, elastic steel, or the like.

When ink is ejected from the nozzle 112, the shutter 130 pivots to open the first slit 124. Therefore, ink ejected from the nozzle 112 passes through the first slit 124. When ink is not ejected from the nozzle 112, the shutter 130 blocks the first slit 124. Accordingly, the ink of the nozzle 112 is blocked from contact with air to prevent the ink from solidifying.

The other surface on which the first groove 126 is formed and the shutter 130 contact each other. When the friction between the head body 120 and the shutter 130 is large, the operation of the shutter 130 may be poor. In addition, when the ink ejected from the nozzle 112 contacts the head body 120 and the shutter 130, the head body 120 and the shutter 130 may be damaged by the chemical action of the ink. Can be.

Therefore, in order to reduce friction between the head body 120 and the shutter 130 and to improve chemical resistance of the head body 120 and the shutter 130, the head body 120 and the shutter 130 are provided. Surfaces may be coated with a material having a low coefficient of friction and high chemical resistance.

Examples of the coating include Teflon coating, ceramic coating, polyethylene (PE) coating, molybdenum (MoS2) coating, polyether etherketone (PEEK) coating (vicote coating), polyamide coating, CONIF coating, Alucoat coating, Polyphenylene sulfide (PPS) coatings, polyacetal (POM) coatings, urethane coatings, nylon coatings may be included. In particular, the Teflon coating is PTFE (Polytetrafluoroethylene) coating, Perfluoroalkoxy (PFA) coating, Fluoroethylenepropylene (FEP) coating, polychlorotrifluoroethylene (PCTFE) coating, Ethylene Tetrafluoroethylene (ETFE) coating, polyvinylidenefluoried (PVDF) coating, Ethylene-Chlorotrifluoro Ethylene (ECTFE) coating , Teflon SF coating, Teflon-S dry lubrication coating, Teflon-S One coat coating, and the like.

Accordingly, friction between the head body 120 and the shutter 130 may be reduced, and the head body 120 and the shutter 130 may be prevented from being damaged by the ink.

The shutter driver 140 is disposed on one side of the head body 120 and fixes one end of the shutter 130. The shutter driver 140 provides a driving force for rotating the shutter 130. Examples of the shutter driver 140 may include a stepping motor, a servo motor, a piezo motor, a DC motor, and the like.

Since the shutter driver 140 can precisely control the operation, shock and noise may be reduced when the shutter 130 is opened and closed, and the opening and closing speed of the shutter 130 may be increased. In addition, the shutter driver 140 is relatively small in size and occupies less space.

Although not shown, the shutter 130 may open and close the first slit 124 by linear reciprocating motion. When the shutter 130 linearly reciprocates, the shutter driver 140 may provide a driving force for the linear reciprocating motion of the shutter 130. In this case, examples of the shutter driver 140 may include a linear motor, a piezo actuator, a voice coil, a solenoid, and the like.

The shutter driver 140 may be equipped with a reducer 142. The reducer 142 reduces the rotational speed of the shutter driver 140 but improves the rotational force of the shutter driver 140. Therefore, the opening and closing operation of the shutter 130 is made stable.

The bracket 144 fixes the shutter driver 140 to the head body 120. The bracket 144 may be coupled to the head body 120 by a screw.

The detector 146 detects whether the shutter 130 is opened or closed, and includes a detection member 147 and a sensor 148.

The detection member 147 is mounted to the rotating shaft of the shutter driver 140. For example, the detection member 147 may be in the form of a disc with an open portion. Therefore, opening and closing of the shutter 130 varies according to the rotation of the detection member 147.

The sensor 148 is mounted to the bracket 144 and detects the detection member 147 that is rotated by the shutter driver 140. Whether the sensor 148 detects the detection member 147 depends on whether the shutter 130 is opened or closed.

For example, when the shutter 130 is opened, the detection member 147 is detected by the sensor 148, and when the shutter 130 is blocked, the detection member 147 is connected to the sensor 148. It may not be detected. As another example, when the shutter 130 is opened, the detection member 147 is not detected by the sensor 148, and when the shutter 130 is blocked, the detection member 147 is the sensor 148. Can be detected.

The sensor 148 may directly detect the position of the shutter 130 without the detection member 147. In addition, even when the shutter 130 linearly reciprocates, the sensor 148 may directly detect the position of the shutter 130.

The elastic member 149 is provided on the rotation shaft of the shutter driver 140. For example, the elastic member 149 may be a coil spring. The elastic member 149 provides an elastic force to the shutter driver 140 to prevent the shutter 130 from being spaced apart from the other surface on which the first groove 126 is formed. Accordingly, the other surface on which the first groove 126 is formed and the shutter 130 may be in close contact with each other.

The suction block 150 is connected to the suction passage 128 of the head body 120. The suction block 150 connects the head body 120 and the suction pipe 312. The suction line 152 is provided with the suction block 150 therein. The suction line 152 has a shape that is repeated S-shaped or U-shaped. Accordingly, the suction line 152 prevents ink remaining in the suction pipe 312 from flowing back to the head body 120 through the suction block 152.

The cover 160 is provided to surround the head body 120. In this case, the cover 160 is in close contact with a portion where the first groove 126 is not formed on the other surface of the head body 120. Since the thickness of the shutter 130 is smaller than the depth of the first groove 126, the cover 160 and the shutter body 130 are spaced apart from each other even if the cover 160 and the head body 120 are in close contact with each other. do. When the shutter 130 rotates reciprocally, friction between the shutter 130 and the cover 160 does not occur. The cover 160 may be formed of a sus material.

The cover 160 has a second slit 162 and a second groove 164.

The second slit 162 is disposed at a position corresponding to the first slit 124. The nozzle 112, the first slit 124, and the second slit 162 are located on the same axis. Therefore, ink of the nozzle 112 may be injected to the outside through the first slit 124 and the second slit 162.

The second groove 164 is formed on the other surface of the cover 160 opposite to one surface in contact with the head body 120. The other surface is a surface facing the object. The second groove 164 extends in a direction perpendicular to the long direction of the second slit 162 including an area where the second slit 162 is formed. The second groove 164 spaces the object from the cover 160.

When the depth of the second groove 162 is smaller than about 0.2 mm, the cover 160 may contact the ink marking portion of the object to damage the marking. When the depth of the second groove 162 is greater than 2 mm, as the gap between the cover 160 and the object increases, the gap between the nozzle 112 and the object also increases to form a marking formed on the object. It can be bad. Thus, the depth of the second groove 162 may be about 0.2 mm to about 2 mm.

The processor 170 is electrically connected to the head 110, the shutter driver 140, and the detector 146. For example, the processor 170 may be connected to the head 110, the shutter driver 140, and the detector 146 through a cable (not shown).

The processor 170 controls the shutter driver 140 to open and close the shutter 130. In addition, the processor 170 confirms the opening and closing of the shutter 130 through the sensing unit 146. The processor 170 controls the ink injection of the head 110 according to the opening and closing of the shutter 130.

The processor 170 includes an interlock unit 172 and an alarm unit 174.

When there is an error in the head 110 and the shutter driver 140, the interlock part 172 stops the operation of the head 110 and the shutter driver 140.

When the operation of the head 110 and the shutter driver 140 is stopped, the alarm unit 174 generates an alarm signal.

The processor 170 is electrically connected to and controlled by the controller 400, but may also operate independently. In addition, the connection distance between the processor 170, the head 110, the shutter driver 140, and the detector 146 may be short, thereby minimizing electrical noise. Thus, the processor 170 may accurately control the ink injection of the head 110 and the opening and closing of the shutter 130.

The case 180 includes the head 110, the head body 120, the shutter 130, the shutter driver 140, the detector 146, the suction block 150, the cover 160, and the processor 170. It is provided to wrap.

FIG. 6 is a schematic block diagram for explaining the ink supply unit 200 and the ink suction unit 300 shown in FIG. 1, and FIG. 7 is a block diagram for explaining the control unit shown in FIG. 1.

1 and 6, the ink tank 210 of the ink supply unit 200 stores ink I used in the inkjet marking apparatus 1000, and is connected to the ink reservoir 250. do.

The ink reservoir 250 is supplied from the ink tank 210 and stores ink I for supplying to the ink ejection unit 100. The ink reservoir 250 is connected to the ink ejection unit 100 through a supply pipe 252.

The first float sensor 260 is provided inside the ink reservoir 250 to measure the ink amount inside the ink reservoir 250 while moving up and down along the liquid level of the ink I. The pressure sensor 270 is provided on one side of an upper surface of the ink reservoir 250 to measure the pressure inside the ink reservoir 250.

The liquid pump 220 is provided on a connection pipe 212 connecting the ink tank 210 and the ink reservoir 250. The liquid pump 220 is determined whether to operate according to the ink amount of the ink reservoir 250 measured by the first float sensor 260. When the ink amount of the ink reservoir 250 is lower than the reference amount, the liquid pump 220 is operated to supply the ink I of the ink tank 210 to the ink reservoir 250.

The filter 240 is provided on the connection pipe 212 and filters impurities and air bubbles in the ink I.

The first air pump 230 is connected to the inside through the upper surface of the ink reservoir 250 to increase the pressure inside the ink reservoir 250. That is, when it is necessary to discharge the ink to the outside of the head 110, by operating the first air pump 230 to pump the outside air into the ink reservoir 250 to increase the pressure.

The drain valve 280 is provided on the outer surface of the ink reservoir 250 to adjust the pressure inside the ink reservoir 250 by opening and closing the valve. That is, when the pressure inside the ink reservoir 250 is higher than a desired pressure (negative pressure), the drain valve 280 is opened, and when the pressure inside the ink reservoir 250 is lower than a desired pressure (negative pressure), the drain valve 280 remains closed. The drain valve 280 is opened and closed by the operation of the solenoid.

Therefore, the pressure in the ink reservoir 250 may be adjusted through the first air pump 230 and the drain valve 280.

The ink container 310 of the ink suction unit 300 stores the ink I sucked through the suction pipe 312. The ink container 310 is preferably maintained in a vacuum state to increase the suction force. The second air pump 320 is connected to the ink container 310 to provide a suction force for sucking the residual ink (I). Foreign substances such as dust of the nozzle 112 may be sucked by the suction force of the second air pump 320.

The second float sensor 330 is provided inside the ink container 310 and checks the amount of ink I collected in the ink container 310. Thus, the collected ink I is prevented from overflowing and flowing back along the suction pipe 312.

1, 6, and 7, the control unit 400 detects a liquid amount when the ink amount of the ink reservoir 250 of the first float sensor 260 or the corresponding sensing device is less than a preset amount. The pump 220 is driven to supply the ink I of the ink tank 210 to the ink reservoir 250. Therefore, the ink reservoir 250 may maintain a constant ink amount.

The control unit 400 drives the first air pump 230 to apply pressure to the ink reservoir 250. Ink I of the ink reservoir 250 is supplied to the nozzle 112 of the ink ejection unit 100 through the supply pipe 252. At this time, the control unit 400 opens the drain valve 280 so that the pressure inside the ink reservoir 250 maintains a negative pressure. Therefore, the ink I supplied to the nozzle 112 is not ejected through the nozzle 112 and does not flow back along the supply pipe 160.

Thereafter, even when the pressure of the ink reservoir 250 changes due to the ejection of the ink I or the change of external conditions, the first air pump 230 and the drain valve 280 are adjusted to maintain the ink I in the above state. do.

 The processor 170 operates the shutter driver 140 under the control of the control unit 400. The shutter driver 140 moves the shutter 130 to open the first slit 124. When the first slit 124 is opened, the nozzle 112 of the head 110 sprays ink I to mark an object. At this time, the control unit 400 drives the first air pump 230 and the drain valve 280 to maintain the pressure inside the ink reservoir 250 in a negative pressure state. Therefore, when the ink I is ejected in the above state, the ink I of the ink reservoir 250 is automatically supplied to the ink ejection unit 100 by the amount of the ink I ejected along the supply pipe 252. .

When the ink injection is finished, the processor 170 operates the shutter driver 140 again under the control of the control unit 400. The shutter driver 140 moves the shutter 130 to block the first slit 124. Therefore, the nozzle 112 of the head 110 is sealed, thereby preventing the ink I of the nozzle 112 from hardening.

In addition, when the injection of the ink I is completed, the control unit 400 operates the second air pump 320. Therefore, the residual ink I of the nozzle 112 is discharged along the suction block 150 and the suction pipe 312 and stored in the ink container 310. When the ink I is hardened to the nozzle 112 due to long periods of non-use or the like, the control unit 400 sprays a small amount of the ink I through the nozzle 112 to draw the nozzle 112 with the ink I. Clean. In this case, cleaning is performed while the nozzle 112 is closed. At this time, the second air pump 320 is operated to discharge the ink I and the solid ink I used for cleaning.

As described above, the ink ejection unit according to the present invention seals the nozzle while the ink is not ejected to block contact with air, thereby preventing the ink from solidifying at the nozzle. In addition, the ink remaining in the nozzle and the ink injected for cleaning the nozzle are sucked to prevent the ink from solidifying in the nozzle.

The ink jetting unit may check the opening and closing operation of the shutter by using a detection unit. Therefore, malfunction of the shutter can be confirmed quickly.

While the foregoing has been described with reference to preferred embodiments of the present invention, those skilled in the art will be able to variously modify and change the present invention without departing from the spirit and scope of the invention as set forth in the claims below. It will be appreciated.

100: ink ejection unit 110: head
112: nozzle 114: locking jaw
116: cable connection 118: heater
120: head body 122: insertion groove
124: first slit 126: first groove
128: suction passage 130: shutter
140: shutter drive unit 142: step motor
144: bracket 146: reducer
147: detection member 148: sensor
149: elastic member 150: suction block
152: suction pipe 160: cap
162: second slit 170: processor
172: interlock unit 174: alarm unit
180: case 200: ink supply unit
210: ink tank 220: liquid pump
230: first air pump 240: filter
250: ink reservoir 252: ink supply piping
260: float sensor 270: pressure sensor
280: drain valve 300: ink suction unit
310: ink container 312: ink suction pipe
320: second air pump 330: float sensor
400: control unit 410: keypad
420: display monitor 500: support
I: Ink

Claims (21)

A head in which a nozzle for ejecting ink to an object is formed;
A head body having an insertion groove into which the nozzle is inserted and a slit communicating with the insertion groove and passing ink ejected from the nozzle, for holding and supporting the head; And
And a shutter in contact with the head body to open and close the slit according to whether the nozzle ejects ink. The ink ejection unit according to claim 1, wherein the shutter is made of an elastic material to be in close contact with the head body. The ink jet unit of claim 1, further comprising a driving unit connected to one end of the shutter and moving the shutter to open and close the shutter. The ink ejection unit according to claim 3, wherein the driving unit rotates the shutter reciprocally. The ink ejection unit according to claim 3, wherein the drive unit linearly reciprocates the shutter. 4. The ink ejection unit according to claim 3, further comprising an elastic member mounted to the driving unit and providing an elastic force such that the shutter is in close contact with the head body. The ink ejection unit of claim 3, further comprising a sensing unit provided at one side of the head body to confirm whether the shutter is opened or closed. The method of claim 7, wherein the detection unit,
A sensing member mounted to the driving unit and moving according to the driving of the driving unit; And
And a sensor mounted on one side of the head body to detect the sensing member. The ink ejection unit of claim 7, wherein the sensing unit comprises a sensor mounted to the head body to sense a position of the shutter. The ink ejection unit of claim 7, further comprising a processor connected to the head, the driving unit, and the sensing unit to control ink ejection of the head and opening and closing of the shutter. 12. The ink ejection unit according to claim 10, wherein the processor further comprises an interlock unit which stops the operation of the head when the shutter is not in operation. The ink ejection unit according to claim 1, wherein the head body has a groove extending in a direction parallel to the long direction of the slit, including a region in which the slit is formed on a surface in contact with the shutter. 13. The ink ejection unit according to claim 12, wherein the depth of the groove is deeper than the thickness of the shutter to accommodate the shutter. The ink ejection unit according to claim 1, further comprising a cover having a second slit at a position corresponding to the slit, and covering the head body. 15. The apparatus of claim 14, wherein the cover includes a region in which the second slit is formed on a surface facing the object to space the marking surface of the object and the cover in a direction perpendicular to the long direction of the second slit. An ink ejection unit having an extending groove. The ink ejection unit according to claim 1, wherein the surfaces of the head body and the shutter are coated to reduce friction between the head body and the shutter and to improve chemical resistance of the head body and the shutter. The method of claim 16, wherein the coating is Teflon coating, ceramic coating, polyethylene (PE) coating, molybdenum (MoS2) coating, PEEK (Polyether etherketone) coating (vicote coating), polyamide (Poly Amide) coating Ink jet unit, characterized in that any one of, CONIF coating, Alucoat coating, polyphenylene sulfide (PPS) coating, polyacetal (POM) coating, urethane coating, nylon coating. The ink ejection unit according to claim 1, wherein the head body extends from an inner side wall of the insertion groove to a surface into which the head is inserted, and has a suction passage for sucking ink remaining in the nozzle. 19. The apparatus of claim 18, further comprising a suction block having an S-shaped suction line which is repeated to prevent backflow of ink sucked through the suction passage, and connected to the suction passage of the head body. Ink jet unit. The ink jet unit of claim 1, wherein the head body and the shutter are made of one of polyimide, polyether ether ketone, stainless steel, and elastic steel. An ink ejection unit for ejecting ink toward an object, an ink supply unit for supplying ink to the ink ejection unit, an ink suction unit for sucking residual ink in the ink ejection unit, the ink ejection unit, and the ink A control unit for controlling an operation of a supply unit and the ink suction unit,
The ink ejection unit,
A head having a nozzle configured to spray the ink onto an object;
A head body having an insertion groove into which the nozzle is inserted and a slit communicating with the insertion groove and passing ink ejected from the nozzle, for holding and supporting the head; And
And a shutter in contact with the head body, the shutter opening and closing the slit according to whether the nozzle ejects ink.

Images