JP2016210013A - Maintenance mechanism and method of ink jet printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a maintenance mechanism of an ink jet printer which can surely remove fluff and powder from a base material adhering to a surface and a side surface of an ink jet head.SOLUTION: A maintenance mechanism in an ink jet printer for forming an image by discharging ink from an ink jet head 40 having an ink discharge port comprises: a washing pool 111 which is filled with liquid, provided so as to be able to contact/separate with respect to the ink jet head 40, and brought close to the ink jet head 40 so as to allow the ink jet head 40 to be immersed in the liquid; a side part wipe blade 112 which is arranged at a position higher than the water level of the liquid on the inner wall surface of the washing pool 111 and brought into slide contact with the side surface of the ink jet head 40 following contact/separation of the washing pool 111; and a suction pump 114 which sucks the liquid and deposited objects in the washing pool 111 to the outside of the washing pool 111.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a maintenance mechanism and method for an inkjet printing apparatus that forms an image by ejecting ink onto a medium such as paper or a building material using an inkjet head having a nozzle that is an ink ejection port.

  Conventionally, various ink jet printers having a nozzle surface provided with a large number of nozzles for ejecting ink have been developed. The application range of this ink jet printer has been expanded, and in recent years, a technique for decorating a base material such as a building material by printing using such an ink jet type printing apparatus has also become widespread. Here, when printing a base material such as a building material, foreign matters such as powder that has soared or a mark on the surface of the base material may adhere to the nozzle surface. If printing is continued in a state where these are left unattended, normal ejection performance such as non-ejection and deflection cannot be secured.

  Therefore, a method has been devised in which the ink jet head is brought into contact with the cleaning liquid contained in the container in order to remove these foreign substances adhering to the periphery of the nozzle of the ink jet head (for example, see Patent Document 1).

JP 2004-167772 A

  However, in the technique disclosed in Patent Document 1 described above, since the inkjet head is brought into contact with the cleaning liquid, the cleaning liquid does not reach the side surface of the inkjet head, and the fixed matter adhering to the side surface is sufficiently removed. For example, if a fixed object adheres to the nozzle surface by wiping or the like, the meniscus at the ejection port of the inkjet head is not properly formed, and normal ejection performance cannot be ensured, and image quality deteriorates. .

  In particular, when decorating building materials, when printing with an inkjet printer, it is necessary to reduce the distance between the printing substrate and the inkjet head nozzle surface as much as possible to improve image quality. Since bending and floating occur, there is a possibility of contact with the ink jet head. For this, for example, a countermeasure for protecting the nozzle surface by mounting a nozzle guard on the head nozzle surface is known.

  However, since the nozzle guard is bonded to the nozzle plate on which the ejection port of the inkjet head is disposed with an adhesive or the like, a gap may be formed. The inkjet head equipped with the nozzle guard is a water dispersible resin. If the ink containing the ink is continuously used, there is a high possibility that the adhered ink will be accumulated in the gap between the nozzle guard and the nozzle plate. In addition, if there are blemishes or powder on the surface of the printing substrate, continuation of printing may cause blemishes or dust to adhere to the head nozzle surface or inside the nozzles, and deposits such as ink sticking matter, blemishes, or powder will accumulate. Then, there is a possibility that the printing base material is soiled or the print head cannot be discharged finally and needs to be replaced.

  The present invention has been made in view of the above problems, and in an inkjet printing apparatus, wiper means that supplies a sufficient amount of cleaning liquid to the side surface of the inkjet head and is also slidable in contact with the side surface of the inkjet head. It is an object of the present invention to provide a maintenance mechanism and method that can reliably remove scraps and powders from a base material adhering to the side surface of an inkjet head.

In order to achieve the above object, the maintenance mechanism according to the present invention has the following features:
A maintenance mechanism in an ink jet printing apparatus that forms an image by ejecting ink from an ink jet head having an ink ejection port,
A cleaning pool that is filled with a liquid, is provided so as to be relatively close to and away from the ink jet head, and allows the ink jet head to be impregnated in the liquid by being relatively close to the ink jet head. When,
On the inner wall surface of the cleaning pool, a side wipe blade is disposed at a position higher than the water surface of the liquid, and is slidably contacted with the side surface of the inkjet head as the cleaning pool contacts and separates;
It is in having.

A feature of the maintenance method according to the present invention is a maintenance method in an inkjet printing apparatus that forms an image by ejecting ink from an inkjet head having an ink ejection port,
A step of providing a cleaning pool filled with a liquid so as to be relatively close to and away from the inkjet head, and impregnating the inkjet head into the liquid by bringing the inkjet pool relatively close to the inkjet head; ,
A step of sucking the liquid and solid matter in the cleaning pool out of the cleaning pool by a suction means; and a wipe blade disposed at a position higher than the water surface of the liquid on the inner wall surface of the cleaning pool, and the cleaning A step of sliding on the side surface of the inkjet head with the contact and separation of the pool for use;
It is in having.

  According to the maintenance mechanism of the ink jet printing apparatus according to the present invention, the cleaning pool is attached to the ink jet head by relatively approaching the ink jet head and immersing the ink jet head in a liquid such as a cleaning liquid in the cleaning pool. In addition to dissolving the adhered matter, the side wipe blade in the cleaning pool is brought into sliding contact with the side surface of the inkjet head in accordance with the relative contact (separation, rise, fall, etc.) of the cleaning pool, thereby It is possible to clean the periphery of the ink jet head by removing foreign matters such as powder and debris adhering to the nozzle surface and its periphery.

  As a result, according to the present invention, for example, even if the inkjet head has a complicated configuration due to components constituting the inkjet head, such as a nozzle plate and a nozzle guard, and components protecting these components. , Without damaging these parts, it is possible to remove the sticking ink adhering in the gap between the parts, removing the nozzle guard, physically scraping off the sticking thing from the gap between the nozzle plate and the nozzle guard, etc. In addition, it is possible to remove nozzle clogs, nozzle guards such as scrapes and dust, and deposits on the surface of the nozzle plate.

  According to the maintenance method of the inkjet printing apparatus according to the present invention, the cleaning pool is moved closer to the inkjet head, and the inkjet head is immersed in a liquid such as a cleaning liquid in the cleaning pool. Ink jet head by dissolving attached solid matter and sliding the side wipe blade in the cleaning pool against the side surface of the ink jet head as the cleaning pool moves relative to and away from the cleaning pool. It is possible to remove foreign matters such as powder and kerks adhering to the side surfaces together with the cleaning liquid.

  In addition, the fixed matter removed from the inkjet head is sucked by the suction means together with the cleaning liquid and ink in the cleaning pool, so that the fixed matter floating or precipitated in the cleaning liquid is prevented from adhering to the inkjet head again. Is done. At this time, by sucking with the suction means while the inkjet head is immersed in the liquid in the cleaning pool, the ink can be sucked from the discharge port of the inkjet head with the negative pressure by the suction, Fixed matter can also be removed and sucked. In addition, it is preferable to perform the suction and discharge of the liquid in the cleaning pool at a necessary timing according to the degree of contamination of the liquid. As a result, according to the first feature of the maintenance method according to the present invention, for example, the inkjet head has a complicated configuration due to components constituting the inkjet head, such as a nozzle plate and a nozzle guard, and components protecting these. Even if it has, the ink adhering matter adhered in the gap between the parts can be removed without damaging these parts, and the nozzle guard can be removed or the gap between the nozzle plate and the nozzle guard can be removed. This eliminates the need to physically scrape the sticking material from the nozzle, and also eliminates nozzle clogging, nozzle guards such as scrapes and dust, and deposits on the nozzle plate surface.

1 is a front view schematically showing a schematic configuration of an ink jet printing apparatus according to an embodiment of the present invention. It is a front view which shows typically the structure of the maintenance mechanism which concerns on embodiment. It is a functional block diagram which shows the structure of the fixed thing removal mechanism which concerns on embodiment, and the relationship with the drive of a maintenance. It is a perspective view which shows the structure of the side part wipe blade which concerns on embodiment. It is explanatory drawing which shows the state of the inkjet head immersed in the pool for washing | cleaning which concerns on embodiment, The figure (a) is the front view, The figure (b) is the bottom view. It is explanatory drawing which shows typically the structure of the wipe part which concerns on embodiment, The figure (a) is the front view, The figure (b) is the bottom view. It is explanatory drawing which shows typically the structure of the spit part which concerns on embodiment, The figure (a) is the front view, The figure (b) is the bottom view. (A) is a flowchart which shows the maintenance operation | movement which concerns on embodiment, The figure (b) is a flowchart figure which shows the detail of the adhering matter removal process of step S101 in the figure (a). (A) And (b) is explanatory drawing which shows operation | movement of the adhering matter removal process which concerns on embodiment. (A) And (b) is explanatory drawing which shows operation | movement of the adhering matter removal process which concerns on embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. Throughout the drawings, the same or equivalent parts and components are denoted by the same or equivalent reference numerals. However, it should be noted that the drawings are schematic and different from the actual ones. Moreover, it is a matter of course that portions having different dimensional relationships and ratios are included between the drawings. Further, the embodiment described below exemplifies an apparatus or the like for embodying the technical idea of the present invention, and the technical idea of the present invention includes the material, shape, structure, The layout is not specified as follows. The technical idea of the present invention can be variously modified within the scope of the claims.

(Overall configuration of inkjet printing apparatus)
An overall configuration of an inkjet printing apparatus 1 according to an embodiment of the present invention will be described in detail. FIG. 1 is a front view schematically showing a schematic configuration of an ink jet printing apparatus according to an embodiment of the present invention. FIG. 2 is a front view schematically showing the configuration of the maintenance mechanism according to the embodiment.

  The ink jet printing apparatus 1 of the present embodiment is an ink jet printing apparatus that forms an image by ejecting ink from an ink jet head 40 having an ink ejection port and ejecting ink onto a building material P, as shown in FIG. In addition, a sheet-like or plate-like building material P is horizontally arranged and conveyed downstream in the conveying direction (depth direction on the paper surface), and images and characters corresponding to image data are recorded and printed on the surface of the building material P by an inkjet method. To do. In the present embodiment, the building material is produced by adding an image printed with a decorative ink containing a water-dispersible resin and a color material, which is formed by inkjet printing, to the surface of the building material.

  The schematic configuration of the inkjet printing apparatus 1 includes a transport unit 20 that transports the building material P, a recording unit 30 that records on the building material P, and an inkjet head 40 that is disposed below the recording unit 30 and is provided on the recording unit 30. The maintenance mechanism 10 and the maintenance control unit 60 that controls the cleaning operation of the maintenance mechanism 10 are arranged on the base 1a. In addition, the inkjet printing apparatus 1 includes a control unit that controls the entire apparatus including reception of image data and control of a recording operation, and the maintenance control unit 60 illustrated in FIG. 3 constitutes a part of the control unit. doing.

  The transport unit 20 has a plurality of pinch rollers 23 rotated about a horizontal axis along a main scanning direction orthogonal to the transport direction by a motor 24 on a substantially flat platen 22 extending in the transport direction of FIG. In addition, a plurality of grid rollers 21 supported by the pinch rollers 23 so as to be rotatable around a rotation axis parallel to the rotation axis of the pinch roller 23 are arranged in the transport direction. These grid rollers 21 are aligned on a horizontal plane parallel to the transport direction above the platen 22 and form a transport path for the building material P.

  The recording unit 30 includes a carriage rail 31 extending in the main scanning direction above the transport unit 20 and the maintenance mechanism 10, an inkjet head unit 32 provided movably along the carriage rail 31, and an inkjet head unit. It comprises a motor 33 that reciprocally moves 32 on the carriage rail 31 so that position control and speed control are possible, and an ink cartridge 34 that supplies ink for recording to the inkjet head unit 32.

  In the present embodiment, the ink cartridge 34 is provided with a plurality of colors of ink for performing color recording, and can be supplied to the inkjet head unit 32 for each color via a plurality of ink tubes 35. . The ink-jet head unit 32 is provided with an ink-jet head 40 corresponding to the ink color and recording range on the lower surface side, and the ink supplied from the ink tube 35 is supplied to the ink-jet head 40. In the example shown in FIG. 1, four colors are printed by one head, and ink supply channels for four colors are connected to one head. The ink jet head unit 32 is provided with a cooling fan 36 for keeping the temperature of each ink jet head 40 in an appropriate temperature range.

  The ink jet head 40 is provided with a nozzle plate 42 arranged in parallel to the building material P on the transport unit 20 on the lower surface side of the recording head main body. A predetermined ink drop is placed on the nozzle plate 42 in accordance with image data. A plurality of ink discharge ports (hereinafter referred to as nozzles) are formed. The recording head main body is provided with an ink chamber for supplying ink to each nozzle and an ejection mechanism using, for example, a piezoelectric element. Further, on the nozzle surface side of the nozzle plate 42, a nozzle guard 43 is fixed in close contact with the nozzle plate 42. The nozzle guard 43 is formed so as to cover the nozzle row of the nozzle plate 42 and has an opening at a portion corresponding to the nozzle row.

  The position control and speed control of the motor 33 are performed according to a control signal of a control unit (not shown). During the recording operation, the inkjet head unit 32 is reciprocated on the building material P at a predetermined speed in the main scanning direction to perform cleaning. During operation, it can be moved to a predetermined cleaning position in the maintenance mechanism 10.

  The maintenance mechanism 10 includes a fixed matter removing unit 11 that removes solid matter (hereinafter, referred to as a fixed matter) such as scraps and powders attached to the ink jet head 40, and a meniscus forming unit 12 that forms a meniscus by ink on a nozzle. It consists of. More specifically, as shown in FIG. 2, the meniscus forming unit 12 is slidably contacted around the nozzles of the inkjet head 40, thereby wiping the nozzle plate 42, a wiper unit 12 a that performs wiping processing, and a thickened ink by discharging ink. And a spit portion 12b for performing spit processing which is a preliminary discharge operation for removing the above from the nozzle. In the present embodiment, the maintenance mechanism 10 is arranged on the moving path of the inkjet head unit 32 on the side of the transport unit 20 and below the recording unit 30, from the transport unit 20 side, to the fixed object removing unit 11 and the meniscus forming unit. They are arranged in the order of twelve. And the upper position of these fixed substance removal part 11 and the meniscus formation part 12 is a predetermined cleaning position, and the cleaning process in each part is performed when the inkjet head 40 moves above each part.

  The control unit including the maintenance control unit 60 is a processor such as a CPU or DSP (Digital Signal Processor), memory, hardware such as other electronic circuits, software such as a program having the function, or a combination thereof. Various functional modules are virtually constructed by appropriately reading and executing a program, and each constructed functional module performs various processes for operation control of each unit and various user operations. . In particular, in the present embodiment, at the time of maintenance, each part of the maintenance mechanism 10 is controlled to perform the fixed object removal process, the wiping process, the spit process, and the like.

(Configuration of maintenance mechanism 10)
Next, the configuration of each part of the maintenance mechanism 10 will be described. FIG. 3 is a functional block diagram showing the configuration of the fixed object removing unit 11 according to the present embodiment and the relationship between maintenance driving, and FIG. 4 shows the configuration of the side wipe blade 112 according to the present embodiment. It is a perspective view shown. FIG. 5 is an explanatory view showing a state of the inkjet head immersed in the cleaning pool 111 according to the present embodiment, where FIG. 5 (a) is a front view and FIG. 5 (b) is a bottom view. It is. Moreover, FIG. 6 is explanatory drawing which shows the structure of the wipe part 12a which concerns on this embodiment, The figure (a) is a front view, The figure (b) is a bottom view. FIG. 7 is an explanatory view showing the configuration of the spit portion 12b according to the present embodiment, where FIG. 7 (a) is a front view and FIG. 7 (b) is a bottom view.

(1) Structure of the fixed matter removing unit 11 As shown in FIG. 3, the fixed matter removing unit 11 includes a cleaning pool 111, a side wipe blade 112, a lift drive unit 71, a suction pump 114, a pump drive unit 73, and a vibration. A body 116 and a vibrator driving unit 72.

  Among these, at least the cleaning pool 111 and the side wipe blade 112 are provided for each inkjet head 40. However, the lifting drive unit 71, the vibrator drive unit 72, the pump drive unit 73, and the suction pump 114 are provided for each of the plurality of cleaning pools 111 when each operation can be shared for each inkjet head 40. It is good also as a structure. Hereinafter, for convenience of explanation, an example of a configuration in which one inkjet head 40 is provided for each will be described.

  The cleaning pool 111 has a box shape opened upward, and is a member that surrounds the region of the nozzle plate 42 including all the nozzles of the ink jet head 40 from below by covering the nozzle plate 42 from below. The cleaning liquid 113 is filled. Further, as shown in FIGS. 5A and 5B, the cleaning pool 111 is filled with the cleaning liquid 113 that is a liquid in the nozzle plate 42, the nozzle guard 43, and all the gaps between the nozzle plate 42 and the nozzle guard 43. It has a possible size.

  The cleaning liquid 113 is a liquid that dissolves the fixed matter attached to the nozzle plate 42. In this embodiment, the cleaning solution 113 accumulates in the gap between the nozzle plate 42 and the nozzle guard 43. A cleaning liquid having a function of dissolving (including powder) is used. As the cleaning liquid 113, an aqueous solvent containing water and a surfactant is preferably used. Examples of the surfactant include fatty acid sodium, sodium alkylbenzene sulfonate, sodium alkyl sulfonate, sodium α-olefin sulfonate, sodium alkyl sulfate ester, sodium alkyl ether sulfate ester, sodium α-sulfo fatty acid ester, sodium alkyl phosphate ester. Anionic surfactant such as alkyl cationic trimethylammonium, dialkyldimethylammonium, etc .; sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, sucrose fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene alkyl Nonionic surfactants such as phenyl ethers; sodium alkylamino fatty acids, alkylbetaines, alkylamines Amphoteric surfactants such as oxide can be used. In addition, polymer surfactants, silicone surfactants, fluorine surfactants, acetylene glycol surfactants, and the like can also be used. Among these, it is preferable to use polyoxyethylene alkyl ether, the HLB value is 11 to 17, the number of carbon atoms of the alkyl group is 8 to 15, and the number of added moles of ethylene oxide is more preferably 6 to 25.

  It is preferable that the cleaning liquid 113 further includes a thickener. As the thickener, a water-soluble polymer thickener or a clay mineral thickener can be used. As the water-soluble polymer thickener, natural polymers, semi-synthetic polymers, and synthetic polymers can be used. Examples of natural polymers include plant-based natural polymers such as gum arabic, carrageenan, guar gum, locust bean gum, pectin, tragacanth gum, corn starch, konjac mannan, agar; Animal-based natural polymers such as gelatin, casein, and glue can be used. Examples of semi-synthetic polymers include cellulose-based semi-synthetic polymers such as ethyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, and hydroxypropyl methyl cellulose; starch-based compounds such as hydroxyethyl starch, sodium carboxymethyl starch, and cyclodextrin. Semi-synthetic polymers; Alginate-based semi-synthetic polymers such as sodium alginate and propylene glycol alginate; sodium hyaluronate can be used. As the synthetic polymer, for example, vinyl-based synthetic polymers such as polyvinyl pyrrolidone, polyvinyl alcohol, polyvinyl methyl ether, poly N-vinylacetamide, and polyacrylamide; polyethylene oxide, polyethyleneimine, and polyurethane can be used. As the clay mineral-based thickener, for example, smectite-based clay minerals such as montmorillonite, hectorite, and saponite can be used. Among these, it is preferable to use hydroxypropyl methylcellulose.

  Furthermore, in addition to the above components, the cleaning liquid 113 can optionally contain a water-soluble organic solvent, a pH adjuster, an antioxidant, an antiseptic, and the like as appropriate. The viscosity of the cleaning liquid 113 is preferably 5 to 200 mPa · s, more preferably 10 to 100 mPa · s at 23 ° C.

  The cleaning pool 111 is provided so as to be able to contact with and separate from the ink jet head 40 by driving of the elevating drive unit 71, and as shown in FIG. 40 can be immersed in the cleaning liquid 113.

  The raising / lowering drive part 71 performs an up-and-down movement for selectively switching the position of the cleaning pool 111 in the up-and-down direction, and includes, for example, appropriate mechanical, electromagnetic, and fluid raising / lowering means. Therefore, the lift drive unit 71 moves the cleaning pool 111 up and down with respect to the inkjet head unit 32 that is moved on the carriage rail 31 by the motor 33 and positioned above the fixed object removing unit 11. The state in which the inkjet head 40 is immersed in the liquid in the cleaning pool 111 and the state in which the immersion state is released after being detached from the liquid can be switched.

  Further, a side wipe blade 112 is formed on the inner wall surface of the cleaning pool 111 so as to be positioned higher than the water surface of the cleaning liquid 113. For example, as shown in FIG. 4, the side wipe blade 112 has an annular shape having a through-hole 112 a having a shape that matches the shape of the inkjet head 40. The ink jet head 40 is in sliding contact with the side surface. Moreover, it does not necessarily need to be annular, and a plurality of members including the wipe blade 112 may be combined to form an annular shape. Note that the side wipe blade 112 is formed of an elastically deformable member such as a rubber blade having elasticity that does not damage the side surface of the inkjet head 40.

  A suction pipe 115 for discharging the filled cleaning liquid 113 is provided on the bottom surface of the cleaning pool 111, and a suction pump 114 is connected to the suction pipe 115. The suction pump 114 is a suction device that sucks the cleaning liquid 113 and the fixed matter 45 in the cleaning pool 111 out of the cleaning pool 111 and discharges them outside, and employs a fluid pump having an appropriate configuration, such as a rotary pump. be able to. In the present embodiment, the suction amount can be varied by the pump drive unit 73. For example, in the case of a rotary pump, the suction amount is changed by controlling the flow rate per unit time by varying the number of rotations of the pump by the pump drive unit 73. The suction amount of the suction pump 114 can be changed in multiple stages by the pump drive unit 73. The suction pump 114 has a suction port connected to the suction tube 115 and a discharge port connected to the discharge tube 117. The other end of the discharge pipe 117 is connected to a waste liquid bottle.

  The vibrating body 116 is a device that is brought into contact with the liquid filled in the cleaning pool 111 and generates vibrations with respect to the cleaning liquid 113. For example, an ultrasonic wave such as a vibrator or a horn that expands mechanical vibration of the vibrator The body can be used. The vibrating body 116 is controlled by the vibrating body driving unit 72, and is used when it is difficult to dissolve the fixed matter only with a liquid cleaning ability within a certain time. The vibrating body driving unit 72 performs control so that the vibration amplitude of the vibrating body 116 is kept constant.

  As shown in FIG. 5, the vibrating body 116 causes the cleaning liquid 113 to generate a cavitation phenomenon by the ultrasonic wave output from the tip in a state where the inkjet head 40 is immersed in the liquid in the cleaning pool 111. The adhering matter 45 attached to the ink jet head 40 immersed in the cleaning pool 111 is released by an impact caused by a cavitation phenomenon. The position and size of the vibrating body 116 are arbitrary, and the frequency is not limited as long as the fixed object 45 can be released.

  In the fixed object removing unit 11, the elevation driving unit 71, the vibrator driving unit 72, and the pump driving unit 73 are electrically connected to the maintenance control unit 60, and each operation is performed by a control signal from the maintenance control unit 60. To be controlled.

(2) Configuration of Meniscus Forming Unit 12 As shown in FIGS. 6A and 6B, the wipe unit 12a of the meniscus forming unit 12 slides on the nozzle plate 42 of the ink jet head 40 to form the nozzle plate 42. As shown in FIG. 2, a wiping means for removing the adhering fixed matter 45 is provided. A support base is erected on the base 1a and supports the holder portion 122 at the upper portion of the support base. A wipe blade 121 that is slid and cleaned around the nozzle plate 42 of the inkjet head 40 is held at an upper portion 122. The wipe blade 121 is made of an elastically deformable member such as a rubber blade, and is formed in a rectangular thin plate shape. In addition, it is preferable that the material which comprises a wipe part is a material which has the elasticity of the grade which does not damage the nozzle plate 42. FIG. Moreover, it is preferable that the wipe blade 121 has a shape with a slit so that it can enter a recess formed by the nozzle blade 42 and the nozzle guard 43.

  The wipe unit 12a is electrically connected to the maintenance control unit 60, and the operation control of the drive mechanism of the wipe unit 12a is performed by a control signal from the maintenance control unit 60. Specifically, in the wipe unit 12a, the holder control unit 60 is controlled by the maintenance control unit 60 so that the holder unit 122 can be moved in the vertical direction with respect to the support base. The ink jet head 40 is arranged lower than the 40 nozzle plates 42 so that the ink jet head 40 can move to the wiper portion 12a.

  On the other hand, at the time of maintenance, the inkjet head 40 is disposed so as to be higher than the nozzle plate 42, and then the inkjet head unit 32 moves from the wipe part 12a onto the wipe part 12a. Then, the wipe blade 121 is elastically deformed and slides on the nozzle plate 42 by the tip of the wipe blade 121 being in contact with the inkjet head 40 and being relatively moved in the horizontal direction, as shown in FIG. Thus, the ink or wipe liquid remaining on the nozzle plate 42 is wiped off by the tip of the wipe blade 121 being in sliding contact with the nozzle plate 42. At this time, the maintenance control unit 60 changes the speed and the number of times of the wipe blade according to the environmental temperature to prevent the cleaning liquid 113 from being driven to the side of the inkjet head. Note that a temperature measuring device that measures the environmental temperature is provided in the inkjet printing apparatus 1, and the maintenance control unit 60 acquires environmental temperature information from the temperature measuring device.

  On the other hand, the spit portion 12b of the meniscus forming portion 12 is means for performing spit processing, which is a preliminary discharge operation for discharging ink to remove thickened ink and the like from the nozzle, and is shown in FIGS. 7 (a) and 7 (b). As described above, the spit receiving portion 123 that receives the droplets ejected from the nozzles and collects the discarded ink is provided. In this embodiment, the inkjet head unit 32 is controlled by the control of the maintenance control unit 60, and ink is ejected from the nozzles of each inkjet head 40 in order to form a meniscus of the inkjet head 40. During such spit processing, the spit receiving portion 123 is disposed below the inkjet head unit 32.

(Maintenance operation)
Next, the maintenance operation in the inkjet printing apparatus 1 of the present embodiment will be described. FIG. 8A is a flowchart showing the maintenance operation according to the embodiment, and FIG. 8B is a flowchart showing the details of the fixed object removal processing in step S101 in FIG. 9 and 10 are explanatory diagrams showing the operation of the fixed object removal processing according to the embodiment.

  An example of the maintenance operation of the inkjet head 40 in the inkjet printing apparatus 1 is as shown in FIG. 8, in which a fixed substance removing step (step S101) is performed by the fixed substance removing unit 11, and then a wipe process and a spit process are performed by the wipe unit 12a. The meniscus forming step (S102) is sequentially performed. Hereinafter, each process by the maintenance mechanism 10 will be described.

(1) Processing by the fixed matter removing unit 11 In the processing by the fixed matter removing unit 11, first, the maintenance control unit 60 positions the inkjet head unit 32 to face each cleaning pool 111 corresponding to the lower side of each inkjet head 40. As shown in FIG. 9A, the cleaning pool 111 filled with the cleaning liquid 113 is positioned so as to be able to contact and separate from the inkjet head 40. At this time, the suction pump 114 is stopped (pump off).

  Next, the lift drive unit 71 raises the cleaning pool 111 (step S201) and approaches the inkjet head 40, so that the inkjet head 40 is immersed in the cleaning liquid 113 as shown in FIG. After that, it is allowed to stand for a certain time (step S202), the fixed matter 45 is dissolved, and it is easily removed by the suction pump 114.

  Here, in the case where it is difficult to dissolve the fixed matter only with a liquid cleaning ability within a certain time, the vibrator 116 is driven to output an ultrasonic wave according to the degree of the fixed matter (step S203). A cavitation phenomenon is generated in the cleaning liquid 113, and the fixed matter 45 attached to the ink jet head 40 immersed in the cleaning pool 111 is released by an impact caused by the cavitation phenomenon. It should be noted that the leaving and ultrasonic vibration generation in steps S202 and S203 can be appropriately turned on and off according to the amount of the fixed matter, etc., and can be performed at the required number of times and time. Either or both of the generation of sonic vibrations can be omitted or shortened.

  Next, the suction pump 114 is operated by the pump drive unit 73 (step S204). At this time, the pump drive unit 73 performs suction at an appropriate pressure that can remove the dissolved ink adhering matter. Then, by sucking ink from the nozzle with the negative pressure at the time of suction, the fixed matter in the nozzle and the liquid in the cleaning pool 111 are poured out, and as shown in FIG. 10A, the cleaning liquid in the cleaning pool 111 is discharged. 113 is sucked to the suction pipe 115 side and discharged to a waste liquid bottle through a discharge pipe 117. It should be noted that the suctioning and discharging of the fixed substance by the suction pump 114 in step S204 can be performed at a necessary timing according to the degree of contamination of the cleaning liquid 113, and can be omitted if unnecessary.

  When the cleaning liquid 113 in the cleaning pool 111 has been sucked, the suction pump 114 is stopped. Then, the maintenance control unit 60 controls the elevating drive unit 71 to lower the cleaning pool 111 (step S205). Here, on the inner wall surface of the cleaning pool 111, the side wipe blade 112 is disposed at a position higher than the water surface of the cleaning liquid 113. It passes through the through hole 112a of the side wipe blade 112. Then, as shown in FIG. 10B, as the cleaning pool 111 is brought into contact with and separated from, the side wipe blade 112 is brought into sliding contact with the side surface of the inkjet head 40 (step S206), and adheres to the side surface of the inkjet head 40. The fixed matter 45 thus removed is removed. Thereafter, the motor 33 is driven by the control signal from the control unit, and the inkjet head unit 32 is moved onto the wipe unit 12a which is the wipe position.

(2) Process by Wipe Unit 12a Next, the process of the wipe unit 12a will be described. At the time of standby, the wipe part 12a is lowered to a position where the wipe blade 121 does not touch the nozzle plate 42 and is on standby. Thereafter, when the inkjet head unit 32 is moved to the wiper portion 12a side, the maintenance control unit 60 moves the wiper portion 12a up to a predetermined contact amount with respect to the inkjet head 40 to raise the wiper portion 12a.

  In this state, the ink jet head unit 32 is moved in a direction approaching the wiper 12a by driving the motor 33 by a control signal from the controller. When the inkjet head unit 32 moves onto the wipe part 12a, a wiping process is performed by the wipe blade 121 of the wipe part 12a. Specifically, since the wipe blade 121 is disposed at a position where a contact amount with the inkjet head 40 is ensured, the wipe blade 121 formed of an elastic body is loosened when contacting the inkjet head 40, and the nozzle plate 42 is moved. Press. The ink jet head unit 32 moves while the wipe blade 121 presses the nozzle plate 42, so that the wipe blade 121 slides on the surface of the nozzle plate 42. As a result, the ink or wipe liquid remaining on the nozzle plate 42 is removed.

(3) Operation of spit process When the wiping process ends, the spit process is performed thereafter. In this embodiment, the inkjet head unit 32 is controlled by the control of the maintenance control unit 60, and the cleaning liquid 113 and the ink 2 that are slightly pushed in are ejected from the nozzles of each inkjet head 40 by spitting, and finally A meniscus before printing is formed. Then, the ejected ink is collected in the spit receiving portion 123 positioned below.

  As described above, the fixed object removing process, the wiping process, and the spit process are performed in each part of the maintenance mechanism 10, thereby cleaning the inside of the nozzle and forming an appropriate meniscus. The above is the basic sequence, but the suction process to the spit process may be repeated a plurality of times as necessary.

(Action / Effect)
According to the present embodiment, the cleaning pool 111 is brought close to the inkjet head 40, and the inkjet head 40 is immersed in the cleaning liquid 113 such as the cleaning liquid in the cleaning pool 111, thereby fixing the adhered matter attached to the inkjet head 40. The discharge port of the inkjet head 40 is melted and the side wipe blade 112 in the cleaning pool 111 is brought into sliding contact with the side surface of the inkjet head 40 as the cleaning pool 111 is brought into contact (separated or raised). It is possible to clean the periphery of the inkjet head 40 by removing the sticking matter 45 such as powder or fluff adhering to the surface.

  In addition, the fixed matter removed from the inkjet head 40 is sucked by the suction pump 114 together with the cleaning liquid and ink in the cleaning pool 111, so that the fixed matter floating or precipitated in the cleaning liquid adheres to the inkjet head 40 again. Is prevented. At this time, by sucking with the suction pump 114 while the inkjet head 40 is immersed in the cleaning liquid 113 in the cleaning pool 111, ink can be sucked from the discharge port of the inkjet head 40 by negative pressure due to suction. In addition, it is possible to remove / suck the fixed matter in the discharge port.

  As a result, in the present embodiment, the inkjet head 40 has a complicated configuration due to components constituting the inkjet head 40, such as the nozzle plate 42 and the nozzle guard 43, and components protecting these. In addition, the ink adhering matter adhered in the gap between the components can be removed without damaging these components, and the nozzle guard 43 can be removed or the adhering matter can be physically removed from the gap between the nozzle plate 42 and the nozzle guard 43. In addition, it is possible to eliminate the troubles such as scraping off the nozzle guard 43, and also the deposits on the surface of the nozzle guard 43 and the nozzle plate 42 such as nozzle clogging, chipping and powder.

  Further, according to the present embodiment, in the meniscus forming unit 12, the wiped blade 121 removes the fixed matter around the discharge port of the ink jet head 40 by wiping, and the spit receiving unit 123 discharges in order to form the meniscus. By discharging ink from the outlet, it is possible to discharge the cleaning liquid and ink that have entered the discharge port by wiping.

  According to the third feature of the maintenance mechanism of the inkjet printing apparatus 1 according to the present embodiment, the fixed object in the portion immersed in the cleaning liquid 113 of the inkjet head 40 by generating vibrations with respect to the cleaning liquid 113 by the vibrating body. The foreign matter which is the fixed matter 45 can be more reliably removed, and the vicinity of the inkjet head 40 can be cleaned.

 In the above-described embodiment, the serial type inkjet printing apparatus that ejects ink while reciprocating the inkjet head unit 32 has been described as an example, but an image in the main scanning direction orthogonal to the conveyance direction of the building material P is described. The present invention can also be applied to a line head type inkjet printing apparatus in which a plurality of nozzles are arranged in a line over the entire width of the formation region. Further, in the present embodiment, the inkjet printing apparatus that performs printing on the building material P has been described as an example, but the present invention can also be applied to a printing apparatus that performs printing on printing paper. Furthermore, in the present embodiment, the case where the nozzle guard 43 is provided has been described. However, regardless of the presence or absence of the nozzle guard 43, the fixed matter 45 attached to the side surface of the inkjet head 40 by the side wipe blade 112 can be removed. Therefore, the present invention can be applied to a printing apparatus in which the nozzle guard 43 is not provided.

DESCRIPTION OF SYMBOLS 1 ... Inkjet printing apparatus 1a ... Base 10 ... Maintenance mechanism 11 ... Fixed matter removal part 12 ... Meniscus formation part 12a ... Wipe part 12b ... Spit part 20 ... Conveyance part 21 ... Grid roller 22 ... Platen 23 ... Pinch roller 24 ... Motor DESCRIPTION OF SYMBOLS 30 ... Recording part 31 ... Carriage rail 32 ... Inkjet head unit 33 ... Motor 34 ... Ink cartridge 35 ... Ink tube 36 ... Cooling fan 40 ... Inkjet head 42 ... Nozzle plate 43 ... Nozzle guard 45 ... Fixed matter 60 ... Maintenance control part 71 DESCRIPTION OF SYMBOLS ... Elevating drive part 72 ... Vibration body drive part 73 ... Pump drive part 111 ... Cleaning pool 112 ... Side part wipe blade 112a ... Through-hole 113 ... Cleaning liquid 114 ... Suction pump 115 ... Suction pipe 116 ... Vibrating body 117 ... Exhaust pipe 1 1 ... wipe blade 122 ... holder 123 ... spit receiving

Claims (2)

A maintenance mechanism in an ink jet printing apparatus that forms an image by ejecting ink from an ink jet head having an ink ejection port,
A cleaning pool that is filled with a liquid and is provided so as to be able to contact and separate relative to the ink jet head so that the ink jet head can be immersed in the liquid by being relatively close to the ink jet head. When,
On the inner wall surface of the cleaning pool, a side wipe blade is disposed at a position higher than the water surface of the liquid, and is slidably contacted with the side surface of the inkjet head as the cleaning pool contacts and separates;
A maintenance mechanism for an ink jet printing apparatus. A maintenance method in an ink jet printing apparatus for forming an image by ejecting ink from an ink jet head having an ink ejection port,
A step of providing a cleaning pool filled with a liquid so as to be relatively close to and away from the inkjet head, and immersing the inkjet head in the liquid by being relatively close to the inkjet head; ,
A step of sucking the liquid and solid matter in the cleaning pool out of the cleaning pool by a suction means; and a wipe blade disposed at a position higher than the water surface of the liquid on the inner wall surface of the cleaning pool, and the cleaning A step of sliding on the side surface of the inkjet head with the contact and separation of the pool for use;
A maintenance method for an inkjet printing apparatus, comprising: