Drawing machine and cleaning unit

Abstract

To enable nozzle cleaning as intended without causing nozzle malfunction. [Solution] The drawing machine includes a print head 22 for ejecting ink supplied from an ink tank toward an object to be drawn while being transported, a nozzle group consisting of a plurality of nozzles arranged in a line on one end face of the print head 22, a purge control unit that performs a purge process to leak ink remaining in the flow path from the ink tank to the nozzle group to the outside through the nozzle group, and a cleaning unit 400 that has a wiping member for wiping off deposits attached to the nozzle group by the purge process, and positions the wiping member relative to the nozzle group while in contact with one end face of the print head.

Description

Technical Field

[0001] The present disclosure relates to a drawing machine that discharges ink and a cleaning unit for the drawing machine.

Background Art

[0002] For example, a drop-on-demand (DOD) type inkjet printing apparatus that discharges ink onto a packaging material such as cardboard to perform printing is known (see, for example, Patent Document 1). The DOD type inkjet printing apparatus is equipped with a print head in which a large number of nozzles are arranged in a direction orthogonal to the conveyance direction of the object to be drawn.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when dirt such as residual ink, dust, and dirt adheres to the nozzles arranged on the front end face of the print head, the user performs a wiping operation with a cloth so as not to cause nozzle clogging.

[0005] However, since a large number of nozzles are arranged on the narrow front end face of the print head and the size of each nozzle is very small, it is difficult to control the force when the user performs a wiping operation with a cloth. If the extraction is performed with too weak force, there is a risk that the dirt cannot be sufficiently wiped off. On the other hand, if the wiping is performed with too strong force, there is a risk of nozzle failure if dust or dirt is involved.

[0006] The present disclosure has been made in view of such points, and an object thereof is to enable accurate cleaning of the nozzles without inducing nozzle failure. [Means for solving the problem]

[0007] To achieve the above objective, one aspect of this disclosure may be based on a drawing machine that ejects ink for drawing information onto an object to be drawn on, which is transported by a transporter. The drawing machine comprises an ink tank for containing ink, a print head for ejecting ink supplied from the ink tank toward an object to be drawn on while being transported, a nozzle group consisting of a plurality of nozzles arranged in a line on one end face of the print head, a purge control unit that performs a purge process to leak ink remaining in the flow path from the ink tank to the nozzle group to the outside through the nozzle group, and a cleaning unit that has a wiping member for wiping off any deposits adhering to the nozzle group by the purge process, and positions the wiping member relative to the nozzle group while in contact with the one end face of the print head.

[0008] Alternatively, a cleaning unit that can be detachably attached to the drawing machine may be assumed. The cleaning unit comprises a wiping member that wipes off any deposits adhering to the nozzle group by the purging process, and a mounting part that is detachably attached to one end face of the print head on which the nozzle group is arranged, and that positions the wiping member relative to the nozzle group.

[0009] With this configuration, the cleaning unit is attached to one end face of the print head, and the wiping member is positioned relative to the group of nozzles located on that end face. As a result, the relative positional relationship between the wiping member and the group of nozzles is predetermined. This prevents the force applied by the wiping member when it contacts the group of nozzles from being too weak or too strong, allowing for an appropriate level of force. [Effects of the Invention]

[0010] As explained above, with the cleaning unit attached to one end face of the print head, the force applied by the wiping member when it contacts the nozzle group can be adjusted to an appropriate level, allowing the nozzles to be cleaned as intended without causing nozzle failure. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 shows the overall configuration of an inkjet printing apparatus according to an embodiment of the present invention. [Figure 2] Figure 2 is a block diagram of an inkjet printing device. [Figure 3] Figure 3 is a plan view showing an example of the installation of the drawing machine and inspection machine. [Figure 4] Figure 4 is a front view showing an example of the installation of the drawing machine and inspection machine. [Figure 5] Figure 5 is a perspective view of the drawing machine from the front. [Figure 6] Figure 6 is a perspective view of the drawing machine from above with the top cover removed. [Figure 7] Figure 7 is a perspective view showing the absorbent material with the casing removed. [Figure 8] Figure 8 is a perspective view showing the state with the ink receptacle removed. [Figure 9] Figure 9 shows the relative positions of the print head, ink receptacle, and ink tank, and is a view from above. [Figure 10] Figure 10 is a cross-sectional view of the ink receiving section. [Figure 11] Figure 11 is a perspective view of the cleaning unit from the front. [Figure 12] Figure 12 is a perspective view showing the cleaning unit attached to the front end face of the print head. [Figure 13] Figure 13 is a perspective view of the cleaning unit from the rear. [Figure 14] Figure 14 illustrates the installation method of the cleaning unit. [Figure 15] FIG. 15 is an enlarged view of the vicinity of the mounting groove portion of the print head. [Figure 16] FIG. 16 is a side view showing a first modification of the attachment of the print head. [Figure 17] FIG. 17 is a side view showing a second modification of the attachment of the print head. [Figure 18] FIG. 18 is a perspective view showing a state where the cleaning cartridge is removed from the housing. [Figure 19] FIG. 19 is a sectional view taken along line XIX-XIX in FIG. 11. [Figure 20] FIG. 20 is a sectional view taken along line XX-XX in FIG. 11. [Figure 21] FIG. 21 is a plan view of the cleaning unit. [Figure 22] FIG. 22 is a sectional view corresponding to line XXII-XXII in FIG. 20. [Figure 23] FIG. 23 is a view corresponding to FIG. 13 showing a state where the wiping member is removed. [Figure 24] FIG. 24 is a perspective view showing the positional relationship of the bumper member, the input member, the input shaft, and the cam plate. [Figure 25] FIG. 25 is a sectional view corresponding to line XXV-XXV in FIG. 20, showing a case where the first locking mechanism is in a locked state. [Figure 26] FIG. 26 is a view corresponding to FIG. 25 showing a case where the first locking mechanism is in an unlocked state. [Figure 27] FIG. 27 is a sectional view corresponding to line XXVII-XXVII in FIG. 2, showing a case where the second locking mechanism is in a locked state. [Figure 28] FIG. 40 is a view corresponding to FIG. 27 showing a case where the second locking mechanism is being unlocked. [Figure 29] FIG. 29 is a view corresponding to FIG. 27 showing a case where the second locking mechanism has been unlocked. [Figure 30] FIG. 30 is a view corresponding to FIG. 27 showing a case where the second locking mechanism is being locked. [Figure 31]Figure 31 is a cross-sectional view corresponding to the line XXXI-XXXI in Figure 20, showing the case where the third locking mechanism is in the unlocked state. [Figure 32] Figure 32 is a diagram equivalent to Figure 31, showing the case where the third locking mechanism is in the locked state. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described in detail below with reference to the drawings. The following description of preferred embodiments is essentially illustrative and is not intended to limit the present invention, its applications, or its uses.

[0013] Figure 1 is a schematic diagram showing the overall configuration of an inkjet printing apparatus 1 equipped with a drawing machine 2 according to an embodiment of the present invention during operation, and Figure 2 is a block diagram of the inkjet printing apparatus 1. The inkjet printing apparatus 1 includes, for example, a drawing machine 2, an inspection machine 3, a controller 4, and an operating terminal 5.

[0014] The drawing unit 2 is the part that performs the drawing process on the object to be drawn on, and is configured separately from the controller 4. The inspection unit 3 is the part that determines whether the drawing state performed on the object to be drawn by the drawing unit 2 is good or bad, and is configured separately from the controller 4. The inkjet printing apparatus 1 according to this embodiment is equipped with a drawing unit 2 and an inspection unit 3, and is an inkjet printing apparatus that ejects ink to draw information on an object and determines whether the drawing state is good or bad by imaging.

[0015] Controller 4 is the part that controls the drawing machine 2 and the inspection machine 3, and can also be called a control device, control unit, etc. The operating terminal 5 consists of a personal computer or the like, and is the part in which the user performs tasks such as inputting drawing information, making various settings, selections, and confirmations. The operating terminal 5 includes a terminal-side display unit 5a, which consists of, for example, a liquid crystal display, and a terminal-side operation unit 5b, which consists of a keyboard, mouse, pointing device, etc.

[0016] The above configuration example is just one example, and the present invention is not limited to the above configuration example. That is, the controller 4 may be incorporated into the operation terminal 5 or into the drawing machine 2. Alternatively, the operation terminal 5 may function as the controller 4. Figures 1 and 2 show an external device 6 consisting of a programmable logic controller (PLC) or the like, and this external device 6 is connected to the controller 4 in a communicative manner. Control signals output from the external device 6 are input to the controller 4. The external device 6 may be a device that constitutes part of the inkjet printing device 1, or it may be a device separate from the inkjet printing device 1.

[0017] The inkjet printing device 1 is a device for forming a drawing pattern on a workpiece W (an example of an object to be drawn on) that is conveyed horizontally by a conveyor (an example of a conveying device) 10, and is an in-line device used by being incorporated into a manufacturing line (also called a production line). The conveyor 10 is, for example, a belt conveyor, a roller conveyor, etc. The production line is made up of the conveyor 10. The production line is installed in various factories, warehouses, etc. The drawing machine 2 is fixed so that its relative position to the conveyor 10 is in a predetermined positional relationship.

[0018] During operation of the inkjet printing device 1, multiple workpieces W are placed on the transport surface 10a of the transporter 10 and transported sequentially in the direction of arrow A shown in Figure 1. Therefore, the upstream side in the transport direction is the left side of Figure 1, and the downstream side in the transport direction is the right side of Figure 1. The multiple workpieces W are placed on the transport surface 10a with spacing in the direction of arrow A, which is the transport direction. The direction perpendicular to arrow A and along the transport surface 10a is defined as the width direction.

[0019] Workpiece W is not particularly limited, but could include, for example, packaging materials for packing various products. A typical example of packaging material is cardboard. The inkjet printer 1 draws information on the workpiece W being transported by the conveyor 10, such as characters including numbers, symbols, barcodes, two-dimensional codes, images, marks, illustrations, or combinations thereof. When only characters are drawn, the inkjet printer 1 can be called a printing device, and the drawing device 2 can be called a printer. Furthermore, the drawing of information by the inkjet printer 1 also includes printing images, etc. In this case, the inkjet printer 1 can be called a printing device. In the following explanation, the term "drawing" will be used to include both printing and image printing.

[0020] Furthermore, the controller 4 is connected to an encoder 7 for detecting the position of the workpiece W, and a detection sensor 9, which will be described later. Based on the signals output from the encoder 7 and the detection sensor 9, the controller 4 detects the position of the workpiece W. The controller 4 controls the drawing machine 2 so that drawing begins when the workpiece W reaches a predetermined position.

[0021] (Configuration of drawing machine 2) The drawing machine 2 is a DOD (Drop On Demand) type drawing machine that ejects ink only when necessary for drawing operations. However, it may also be a CIJ (Continuous Ink Jet) type drawing machine that ejects ink even when not performing drawing operations. The following description will explain the case in which a DOD type drawing machine is used as drawing machine 2 in this embodiment.

[0022] As shown in Figure 2, the drawing machine 2 includes an ink supply unit 20, a print head drive unit 21, and a DOD print head (hereinafter referred to as the print head) 22. The drawing machine 2 also includes a drawing machine body 25 (shown in Figure 1) on which the print head 22 is installed. The drawing machine body 25 is fixed to a transporter 10 or the like.

[0023] The print head 22 is fixed inside the drawing machine body 25, and the positional relationship between the drawing machine body 25 and the print head 22 is fixed. The ink supply unit 20 and the print head drive unit 21 are also housed inside the drawing machine body 25.

[0024] The print head 22 of the DOD-type drawing machine 2 is, for example, a component corresponding to the ejection unit, and ejects ink supplied from a removable ink cartridge 300 toward the workpiece W that is transported by the transporter 10. The nozzle group 22a, consisting of multiple nozzles provided on the front end face (one end face) of the print head 22, is arranged in the direction of gravity, i.e., vertically.

[0025] A drawing pattern is formed on the workpiece W by ink ejected from the nozzle group 22a of the printhead 22. There are several types of printhead structures, but any of them may be, for example, a thermal inkjet type, a valve jet type, or a piezo type. In this embodiment, a piezo type printhead is used as the printhead 22, which is capable of drawing from low to high resolution, has a wide drawing width, and has high durability. The ink ejected from the printhead 22 is ejected from the drawing machine body 25 to the outside of the drawing machine body 25 and adheres to the workpiece W.

[0026] The ink supply unit 20 is the part that supplies ink to the print head 22, and includes an ink tank 20a that houses the ink to be supplied to the print head 22, and an ink cartridge 300 for replenishing the ink in the ink tank 20a.

[0027] The print head drive unit 21 is controlled by the control unit 40, which will be described later, when performing drawing operations. The print head drive unit 21 generates a drive electrical waveform for driving the print head 22 and outputs it to the print head 22. The drive electrical waveform is a waveform for individually driving the drive elements (piezo oscillators) provided at each ejection port of the print head 22 at timings based on the drawing command output from the control unit 40.

[0028] (Configuration of the inspection machine) Inspection machine 3 is a device that determines the quality of the drawing state of the drawing pattern drawn on the workpiece W based on the drawing data, using an image acquired by imaging the workpiece W, and corresponds to an image inspection unit. Inspection machine 3 can also be called an image inspection device. Inspection machine 3 is installed downstream of drawing machine 2, and is capable of inspecting the drawing state of the workpiece W drawn by drawing machine 2.

[0029] (Integrated fittings) As shown in Figure 1, the inkjet printer 1 is equipped with an integrated fitting 90 for fixing the inspection machine 3 to the drawing machine body 25 which houses the print head 22. The integrated fitting 90 has a part to which the drawing machine body 25 is attached and a part to which the inspection machine 3 is attached. The integrated fitting 90 has a predetermined dimension in the direction of transport of the workpiece W, and when the inspection machine 3 is fixed to the drawing machine body 25 by the integrated fitting 90, the inspection machine 3 and the print head 22 can be positioned at a distance from each other in the direction of transport of the workpiece W, that is, in a fixed position relationship. By fixing the inspection machine 3 to the drawing machine body 25 with the integrated fitting 90, the relative fixed position relationship with the print head 22 is defined.

[0030] Figure 3 is a plan view showing an example of the installation of the drawing machine 2 and the inspection machine 3. When the workpiece W is being transported in the direction of arrow A, the inspection machine 3 can be installed downstream of the drawing machine 2 in the direction of workpiece W transport by providing the integrated fitting 90 as shown by the solid line. On the other hand, when the workpiece W is being transported in the direction of arrow B, opposite to the direction of arrow A, the inspection machine 3 can be installed downstream of the drawing machine 2 in the direction of workpiece W transport by providing the integrated fitting 90 as shown by the dashed line. In addition, by providing both the integrated fitting shown by the solid line and the integrated fitting 90 shown by the dashed line, it is possible to accommodate both the transport directions of arrow A and arrow B.

[0031] Figure 4 shows an example of the installation of the drawing machine 2 and the inspection machine 3, and is a view from the side from which the ink is ejected (front view). As shown in Figure 4, the inspection machine 3 is fixed to the drawing machine body 25 by an integrated fitting 90 such that the vertical center of the drawing area and the vertical center of the field of view of the imaging unit 31 of the inspection machine 3 are at the same height.

[0032] (Detection sensor) As shown in Figure 1, the inkjet printing apparatus 1 is equipped with a detection sensor 9 that detects the arrival of a workpiece W being transported by a transporter 10. The detection sensor 9 is installed upstream of the drawing machine 2 in the transport direction of the workpiece W. The detection sensor 9 is equipped with, for example, an optical motion measuring sensor or a distance sensor (not shown), and these sensors enable the detection of the arrival of the transported workpiece W. When the detection sensor 9 detects the arrival of the workpiece W, it transmits a detection signal to the controller 4. Based on the detection signal output from the detection sensor 9, the controller 4 determines that the workpiece W has arrived at a predetermined position and, after a predetermined drawing delay time has elapsed, causes the drawing machine 2 to start drawing.

[0033] (Controller 4 configuration) As shown in Figure 2, the controller 4 comprises a control unit 40, a storage unit 41, and an operation display unit 42. The control unit 40 is composed of a microcomputer including, for example, a central processing unit and various memories, and is capable of executing pre-stored software. The control unit 40 is provided with a drawing setting unit 40a, a drawing data generation unit 40b, an inspection setting unit 40c, a display screen generation unit 40d, and a mode switching unit 40e. The drawing setting unit 40a, drawing data generation unit 40b, inspection setting unit 40c, display screen generation unit 40d, and mode switching unit 40e of the control unit 40 are parts composed of hardware and software, and for convenience they are described separately as the drawing setting unit 40a, drawing data generation unit 40b, inspection setting unit 40c, display screen generation unit 40d, and mode switching unit 40e, but they may be integrated in hardware.

[0034] The operation display unit 42 includes a controller-side display unit 42a, which is, for example, a liquid crystal display, and a controller-side operation unit 42b, which is, for example, an operation key. The controller-side operation unit 42b is the part that accepts various operations such as drawing content and settings. Various screens generated by the display screen generation unit 40d are displayed on the controller-side display unit 42a, so that the user can operate the controller-side operation unit 42b while looking at the controller-side display unit 42a. The operation status of the controller-side operation unit 42b can be acquired by the control unit 40.

[0035] The controller-side operation unit 42b may be a touch panel. The touch panel is a component capable of detecting operations performed by the user's finger. The type of touch panel is not particularly limited and examples include capacitive touch panels and infrared touch panels. User operation information on the touch panel is transmitted to the control unit 40.

[0036] The drawing setting unit 40a is the part that sets the drawing content to be drawn on the workpiece W to be drawn on. The drawing data generation unit 40b is the part that defines the ejection of ink from the print head 22 and generates drawing data corresponding to the drawing content set in the drawing setting unit 40a. The control unit 40 outputs a control signal to the print head drive unit 21 based on the drawing data generated by the drawing data generation unit 40b, and controls the ejection of ink from the ejection port of the print head 22.

[0037] The inspection setting unit 40c is the part that performs inspection settings by the inspection machine 3. The storage unit 41 is the part that stores the relative fixed position relationship between the inspection machine 3 and the print head 22. Based on the drawing content set by the drawing setting unit 40a and the relative fixed position relationship stored in the storage unit 41, the inspection setting unit 40c assists the user in setting inspection settings.

[0038] (Detailed structure of the drawing machine) Figures 1 to 4 show the approximate shapes of the drawing machine 2, print head 22, drawing machine body 25, ink cartridge 300, etc. However, the specific shapes of the drawing machine 2, print head 22, drawing machine body 25, ink cartridge 300, etc. are shown in Figures 5 and onward. There may be some differences between the shapes shown in Figures 5 and onward and those shown in Figures 1 to 4, because Figures 1 to 4 are conceptual diagrams.

[0039] As shown in Figure 5, the drawing machine body 25 is equipped with a box-shaped housing 200 that extends in the longitudinal direction. The ink tank 20a shown in Figure 2 is located inside the housing 200 and is not visible from the outside. In the installed state of the drawing machine 2, the longitudinal direction of the housing 200 coincides with the width direction of the conveyor 10. In this specification, the longitudinal direction of the housing 200 is defined as the front-to-back direction, and the side facing the workpiece W during installation is defined as the front. Also, the side located to the right when viewing the drawing machine 2 from the front is defined as the right side, the side located to the left when viewing the drawing machine 2 from the front is defined as the left side, and the left-to-right direction of the drawing machine 2 is defined as the width direction. This definition of direction is for the convenience of explanation and does not limit the directions according to the present invention.

[0040] As shown in Figure 5, the housing 200 has a shape that is close to a rectangular parallelepiped, with a long front-to-back orientation. Therefore, the front-to-back dimension of the housing 200 is longer than the left-to-right dimension and the up-to-down dimension of the housing 200.

[0041] Because the housing 200 has a shape close to a rectangular parallelepiped, the outer surface of the housing 200 includes six surfaces. Specifically, the outer surface of the housing 200 includes a front surface 201 positioned facing the workpiece W, a rear surface 202 located opposite the front surface 201, a right side surface 203 located to the right when viewed from the direction facing the front surface 201, a left side surface 204 located to the left when viewed from the direction facing the front surface 201, a top surface 205, and a bottom surface 206. The front surface 201, rear surface 202, right side surface 203, and left side surface 204 are surfaces that constitute the outer surface of the housing 200. One end surface in the longitudinal direction of the outer surface of the housing 200 is the front surface 201, and the other end surface in the longitudinal direction of the outer surface of the housing 200 is the rear surface 202. A print head 22 for ejecting ink toward the workpiece W being transported is provided on the front surface 201. The front surface 201 may also be called the front, or the rear surface 202 may be called the back.

[0042] As shown in Figure 5, the drawing machine 2 is equipped with a removable upper cover 230 attached to the drawing machine body 25. Figure 6 shows the state with the upper cover 230 removed. The drawing machine 2 is equipped with an absorbent 240 (shown only in Figure 6) for absorbing ink leaked from the print head 22, and a casing 241 that houses the absorbent 240. The absorbent 240 is made of sponge, fiber, or the like.

[0043] The casing 241 has a vertically elongated shape and is detachably mounted on the front 201 of the housing 200 to the left of the print head 22. Figure 7 shows the casing 241 removed from the drawing machine body 25 and moved forward. As shown in Figure 7, the casing 241 can be removed and replaced from the drawing machine body 25 without removing the upper cover 230.

[0044] The absorber 240 is provided on only one side of the drawing machine body 25, either the left or the right. In this example, the casing 241 housing the absorber 240 is provided on the left side of the drawing machine body 25, so the absorber 240 is not provided on the right side of the drawing machine body 25. For this reason, a box-shaped member 242 that does not house the absorber 240 is detachably provided on the right side of the drawing machine body 25. The shape of the box-shaped member 242 is symmetrical to that of the casing 241. If the absorber 240 is to be provided on the left side of the drawing machine body 25, the casing 241 housing the absorber 240 should be detachably provided on the left side of the drawing machine body 25, and the box-shaped member 242 should be detachably provided on the right side.

[0045] Below the print head 22 in the drawing machine body 25, there is a tray 245 having a liquid transfer structure for guiding ink leaked from the print head 22 to an absorber 240. The tray 245 is detachably provided below the nozzle group 22a on the front surface 201 of the drawing machine body 25. Figure 8 shows the state in which the casing 241 and box-shaped member 242 and the tray 245 have been removed from the drawing machine body 25, and the tray 245 has been moved forward.

[0046] As shown in Figure 9, the tray 245 is formed to extend to the left and right below the print head 22, and as a whole, it has a concave shape that opens upward. A casing 241 housing the absorber 240 is located above the left side of the tray 245, while a box-shaped member 242 is located above the right side of the tray 245. As shown in Figure 10, the bottom surface 245a of the tray 245 slopes downward from the center in the left-right direction toward the left. This allows ink leaking from the print head 22 to be received by the bottom surface 245a of the tray 245 and then flow to the left side, i.e., the side where the absorber 240 is located, so that the ink can be reliably absorbed by the absorber 240. If the absorber 240 is located on the right side, a tray 245 with a bottom surface 245a sloping in the opposite direction can be installed.

[0047] Figure 9 shows the positional relationship between the ink tank 20a and the print head 22. The ink tank 20a is installed at the bottom of the drawing machine body 25. As shown in Figure 9, in a plan view, the ink tank 20a is positioned behind the print head 22, and to the left and right of the print head 22, but not in front of the print head 22. In other words, in this embodiment, the ink tank 20a is provided so as to surround the portion of the print head 22 other than the side with the nozzle group 22a in a plan view.

[0048] As shown in Figure 6, the drawing machine 2 is equipped with an operation button 250. The operation button 250 is a component that receives user instructions for controlling the drawing machine 2. There may be one operation button 250 or two or more. The operation button 250 is located on the upper part of the rear surface 202 of the housing 200, on the opposite side from the print head 22. This allows the user to operate the operation button 250 from the opposite side of the transport machine 10, resulting in good operability. Examples of operation buttons 250 include a test button operated when performing a test drawing, and a cleaning button operated when cleaning the drawing machine 2, but they may be buttons that perform any function.

[0049] The drawing machine 2 is equipped with a waste liquid bottle 251. The waste liquid bottle 251 is used as a recovery tank for collecting ink and is located on the rear surface 202 of the housing 200, on the opposite side from the print head 22. The waste liquid bottle 251 is a container for storing ink that has been supplied from the ink tank 20a to the print head 22 but has not been discharged toward the workpiece W. The ink inlet (not shown), which is the opening of the waste liquid bottle 251, is located at the top of the waste liquid bottle 251 and is formed at a position higher than the liquid level of the ink contained in the ink tank 20a (shown in Figure 9). The ink supplied to the print head 22 that has not been discharged toward the workpiece W is supplied to the opening of the waste liquid bottle 251 by the supply unit and then flows into the interior of the waste liquid bottle 251 from the opening. The waste liquid bottle 251 is configured to be detachable from the drawing machine body 25, so that the ink inside the waste liquid bottle 251 can be discharged as needed.

[0050] Furthermore, as shown in Figure 6 with the top cover 230 removed, the top of the drawing machine body 25 is equipped with an air filter 260 for filtering the air drawn into the drawing machine body 25, a spirit level 261, and a hand valve 262 for manually opening and closing the internal piping. The air filter 260, spirit level 261, and hand valve 262 are arranged in a front-to-back direction. When the top cover 230 is attached to the drawing machine body 25, the air filter 260, spirit level 261, and hand valve 262 are covered by the top cover 230 and are no longer visible from the outside.

[0051] The drawing machine 2 is equipped with a purge control unit 27. The purge control unit 27 is the part that performs a purging process to leak ink remaining in the flow path from the ink tank 20a to the nozzle group 22a to the outside via the nozzle group 22a. For example, by pressurizing the inside of the ink tank 20a, the ink remaining in the flow path from the ink tank 20a to the nozzle group 22a can be sent to the nozzle group 22a and leaked to the outside from the nozzle group 22a. Such a purging process is performed, for example, during maintenance of the drawing machine 2. Maintenance of the drawing machine 2 is started when the user issues a maintenance execution instruction. The purge control unit 27 may be provided in the drawing machine body 25, or it may be a separate unit provided outside the drawing machine body 25. For example, the controller 4 can have a built-in purge control unit 27, in which case the purging process is performed by the purge control unit 27 of the controller 4.

[0052] By performing a purging process, the ink leaking from the nozzle group 22a flows downward. A tray 245 is provided below the nozzle group 22a, so the ink leaking from the nozzle group 22a due to the purging process can be received by the tray 245. The ink received in the tray 245 is then guided by the tray 245 to the absorber 240, where it is absorbed.

[0053] (Cleaning unit) Residual ink may adhere to the nozzle group 22a of the print head 22. Also, since the nozzle group 22a of the print head 22 is exposed to the outside, dust and other debris may adhere to the nozzle group 22a. Residual ink, dust, and other debris are deposits that adhere to the nozzle group 22a. Since these deposits are dirt on the nozzle group 22a, if they remain attached to the nozzle group 22a, it will lead to a deterioration in drawing quality. Therefore, it is necessary to remove the deposits. The printing machine 2 of this embodiment is equipped with a cleaning unit 400 (shown in Figure 11) for wiping off deposits from the nozzle group 22a during maintenance. The cleaning unit 400 is configured so that the deposits can be removed by manual operation by the user, and does not require a built-in power source such as a battery, nor does it require an external power supply.

[0054] As shown in Figure 12, the cleaning unit 400 is positioned relative to the nozzle group 22a while being detachably attached to the front end surface of the print head 22. The front, rear, left, and right sides of the cleaning unit 400 are defined relative to the state in which it is attached to the print head 22, as shown in each figure. The direction of the cleaning unit 400 corresponds to the direction of the drawing machine body 25; the front and rear sides of the drawing machine body 25 correspond to the front and rear sides of the cleaning unit 400, respectively, and the right and left sides of the drawing machine body 25 correspond to the right and left sides of the cleaning unit 400, respectively. The cleaning unit 400 may be positioned relative to the nozzle group 22a in all directions: up and down, front and back, and left and right, but it is sufficient for it to be positioned at least in the front and back direction.

[0055] The cleaning unit 400 is attached to the front end surface of the print head 22 only during maintenance of the drawing machine 2. This allows the cleaning unit 400 to come into contact with the front surface 201 of the print head 22. When the drawing machine 2 is in operation, the cleaning unit 400 is removed from the front end surface of the print head 22. Maintenance includes at least the removal of deposits from the nozzle group 22a, and may also include other cleaning processes and inspections. During maintenance of the drawing machine 2, the cleaning unit 400 can be attached to the front end surface of the print head 22 to remove deposits without moving the drawing machine 2 from its operating position. Alternatively, during maintenance of the drawing machine 2, the cleaning unit 400 may be attached to the front end surface of the print head 22 after moving the drawing machine 2 from its operating position.

[0056] As shown in Figure 13, the cleaning unit 400 has a wiping member 400A for wiping off deposits adhering to the nozzle group 22a by the purging process performed by the purge control unit 27. The wiping member 400A is made of, for example, a nonwoven fabric and is soft and flexible. The vertical dimension of the wiping member 400A is set to be greater than or equal to the dimension from the upper end to the lower end of the nozzle group 22a.

[0057] When the cleaning unit 400 is positioned on the front end surface of the print head 22, the height position of the wiping member 400A becomes the same as the height position of the nozzle group 22a, and the left-right positions of the wiping member 400A and the nozzle group 22a also become the same. This makes it possible to wipe off any deposits adhering to all the nozzles constituting the nozzle group 22a with a common wiping member 400A. In this way, since the wiping member 400A is positioned at least in the front-rear direction relative to the housing 600 of the cleaning unit 400, positioning the cleaning unit 400 at least in the front-rear direction relative to the front end surface of the print head 22 allows for front-rear positioning of the nozzle group 22a formed on the front end surface of the print head 22 and the wiping member 400A in the front-rear direction.

[0058] An example of the attachment / detachment structure of the cleaning unit 400 to the print head 22 will be described. Figure 14 shows the cleaning unit 400 separated from the print head 22. As shown in Figure 14, mounting grooves (sliding parts) 22b are formed on the right and left sides of the front end surface of the print head 22, respectively, extending in the direction of the alignment of the nozzle group 22a. The mounting grooves 22b are open to the front. As shown in an enlarged view in Figure 15, a protruding ridge 22c extending in the vertical direction is formed in the open portion of the mounting groove 22b. A guide surface 22g is formed at the upper end of the protruding ridge 22c, which is inclined so that it is located further forward as it goes upward. The upper end of the mounting groove 22b is open upward. As shown in Figure 14, a recess 230a is formed on the front end surface of the upper cover 230 above the mounting groove 22b.

[0059] As shown in Figure 13, rail sections 401 are formed on the right and left sides of the rear surface of the cleaning unit 400, respectively, so as to extend vertically and be inserted into the mounting grooves 22b of the print head 22. The distance between the left and right rail sections 401 is set to be the same as the distance between the mounting grooves 22b of the print head 22. The rail sections 401 protrude rearward from the rear surface of the cleaning unit 400. The rail sections 401 are examples of mounting parts that are detachably attached to the front end surface of the print head 22 on which the nozzle group 22a is arranged, and that position the wiping member 400A relative to the nozzle group 22a.

[0060] In other words, when attaching the cleaning unit 400 to the print head 22, as shown in Figure 14, the cleaning unit 400 is positioned above the print head 22, then moved in the direction of the downward arrow, and the lower ends of the left and right rail portions 401 of the cleaning unit 400 are inserted into the mounting grooves 22b of the print head 22 through the open portions at the upper ends of the mounting grooves 22b on the left and right sides of the print head 22. At this time, since a recess 230a is formed on the front end surface of the upper cover 230, the rail portions 401 of the cleaning unit 400 do not interfere with the upper cover 230. In addition, since a guide surface 22g (shown in Figure 15) is formed on the upper end of the protruding portion 22c of the print head 22, the rail portions 401 of the cleaning unit 400 can be easily inserted into the mounting grooves 22b of the print head 22.

[0061] After inserting the rail portion 401 into the mounting groove portion 22b, moving the cleaning unit 400 further in the direction of the arrow causes the rail portion 401 of the cleaning unit 400 to slide against the inner surface and protrusion portion 22c of the mounting groove portion 22b of the print head 22. The cleaning unit 400 moves in the direction of the arrow until the wiping member 400A is at the same height as the nozzle group 22a. When the wiping member 400A is at the same height as the nozzle group 22a, the rail portion 401 of the cleaning unit 400 contacts the stopper (not shown) provided on the print head 22 from above, positioning the cleaning unit 400 in the height direction. Furthermore, when the rail portion 401 is inserted into the mounting groove portion 22b, the rail portion 401 engages with the protrusion portion 22c, restricting the lateral and longitudinal displacement of the cleaning unit 400 relative to the print head 22. This positions the cleaning unit 400 relative to the print head 22. In this manner, the cleaning unit 400 is installed by the user manually sliding it against the inner surface and protrusions 22c of the mounting groove 22b of the print head 22 in the direction of the alignment of the nozzle group 22a. That is, the cleaning unit 400 is held in contact with the front surface 201 of the print head 22, and in this contact state, the cleaning unit 400 is positioned relative to the print head 22. On the other hand, when removing the cleaning unit 400, it is moved upward relative to the print head 22, and the rail portion 401 is removed from the mounting groove 22b.

[0062] Although not shown in the diagram, when attaching the cleaning unit 400 to the print head 22, the cleaning unit 400 may be moved from one side to the other in the left-right direction of the print head 22 before attachment. In this case, the rail portion 401 and the mounting groove portion 22b should be shaped to extend in the left-right direction.

[0063] The structure for attaching the cleaning unit 400 to the print head 22 via manual operation by the user is not limited to the structure described above. For example, as shown in Modification 1 in Figure 16, the user may manually attach the lower part of the cleaning unit 400 to the lower part of the print head 22, then rotate the cleaning unit 400 in the direction of arrow D, and then lift the upper part of the cleaning unit 400 to fit the rail portion 401 into the protruding portion 22c. When the rail portion 401 is fitted into the protruding portion 22c, the cleaning unit 400 is held in contact with the front surface 201 of the print head 22, and in this contact state, the cleaning unit 400 is positioned relative to the print head 22.

[0064] Alternatively, as shown in Modification 2 in Figure 17, a cleaning unit-side magnet 402 and a head-side magnet 22d may be provided on the rear portion of the cleaning unit 400 and the front portion of the print head 22, respectively, and the cleaning unit 400 may be attached to the print head 22 using the magnetic force of the cleaning unit-side magnet 402 and the head-side magnet 22d. The cleaning unit-side magnet 402 and the head-side magnet 22d are permanent magnets, and their magnetic poles are oriented to attract each other. In this Modification 2, after positioning the cleaning unit 400 in front of the print head 22, the user can manually move it closer in the direction of arrow E, and the cleaning unit 400 can be attached to the print head 22 by the mutual attractive force of the cleaning unit-side magnet 402 and the head-side magnet 22d. When the cleaning unit 400 is attached to the print head 22 by the mutual attractive force between the magnet 402 on the cleaning unit side and the magnet 22d on the head side, the cleaning unit 400 is held in contact with the front surface 201 of the print head 22, and in this contact state, the cleaning unit 400 is positioned relative to the print head 22.

[0065] Although not shown in the diagram, a further modification is possible in which the user can bring the cleaning unit 400 into contact with the front surface 201 of the print head 22 by holding the cleaning unit 400 by hand and pressing it against the front surface 201 of the print head 22. Even in this case, since the wiping member 400A is positioned relative to the housing 600 of the cleaning unit 400, when the front surface 201 of the print head 22 and the cleaning unit 400 are in contact, the wiping member 400A is positioned relative to the nozzle group 22a formed on the front surface 201 of the print head 22. When the user presses and brings the unit into contact with the print head 22, the cleaning unit 400 is not held relative to the print head 22, so the user needs to support the cleaning unit 400 during use. However, since there is no need for a structure to attach the cleaning unit 400 to the print head 22, the design is simpler and the manufacturing cost is lower.

[0066] As shown in Figure 18, the cleaning unit 400 comprises a cleaning cartridge 500 and a housing 600 that houses the cleaning cartridge 500. The housing 600 is open at the bottom, allowing the cleaning cartridge 500 to be inserted into the housing 600 from below.

[0067] As shown in Figure 19, the cleaning cartridge 500 comprises a wiping member 400A, a hollow driven shaft 501 on which the wiping member 400A is wound before use, and a hollow drive shaft (winding shaft) 502 for winding up the wiping member 400A after use. The driven shaft 501 is located in the front part of the cleaning cartridge 500 and extends in the vertical direction. The upper and lower ends of the driven shaft 501 are open. The drive shaft 502 is located in the middle part of the cleaning cartridge 500 in the front-rear direction and extends in the vertical direction approximately parallel to the driven shaft 501. The upper and lower ends of the drive shaft 502 are open.

[0068] The wiping member 400A is elongated and has a length that allows it to wipe off deposits from the nozzle group 22a multiple times. Before use, the wiping member 400A is wound onto the driven shaft 501, so that the driven shaft 501 is in a roll shape. When all of the wiping member 400A wound onto the driven shaft 501 has been used, the wiping member 400A is detached from the driven shaft 501 and wound onto the drive shaft 502, and after being removed from the housing 600 as a used cleaning cartridge 500, it is discarded. After that, a new cleaning cartridge 500 is prepared and placed in the housing 600, so that the cleaning unit 400 can be used. In this way, the housing 600 is reusable, while the cleaning cartridge 500 is replaceable.

[0069] As shown in Figure 18, the cleaning cartridge 500 includes a bottom plate portion 503 that rotatably supports the lower end of the driven shaft 501 and the lower end of the drive shaft 502, and an upper plate portion 504 that rotatably supports the upper end of the driven shaft 501 and the upper end of the drive shaft 502. As shown in Figure 19, the bottom plate portion 503 is positioned to face outward from the bottom of the housing 600 and functions as a lid that closes the open portion of the housing 600.

[0070] The upper plate portion 504 has a driven-side opening 504a in the part that supports the upper end of the driven shaft 501, and a driven-side opening 504b in the part that supports the upper end of the drive shaft 502. In addition, a rear-side opening 504c is formed in the upper plate portion 504 in the part rearward from the driven-side opening 504b.

[0071] The cleaning cartridge 500 includes a connecting member 505 that connects the bottom plate portion 503 and the top plate portion 504. The connecting member 505 extends in the vertical direction, with its upper part fixed to the periphery of the top plate portion 504 and its lower part fixed to the periphery of the bottom plate portion 503. In this embodiment, as shown in Figure 19, a plurality of connecting members 505 are provided at intervals from each other in the circumferential direction of the top plate portion 504 and the bottom plate portion 503.

[0072] As shown in Figures 19 and 20, the front of the housing 600 is provided with a window 601 having a light-transmitting material. The wiping material 400A is pre-wound onto the driven shaft 501 to form a roll, and since the driven shaft 501 is located on the front side of the cleaning cartridge 500, the rolled material can be viewed through the window 601. This allows the user to observe the process of the wiping material 400A being used and the roll becoming smaller from outside the housing 600 through the window 601, so that the user can determine the remaining amount of wiping material 400A without removing the cleaning cartridge 500 from the housing 600. Furthermore, when all of the wiping material 400A has been used and wound onto the drive shaft 502, the outer surface of the driven shaft 501 becomes visible from outside the housing 600 through the window 601. This allows the user to determine that the unused wiping material 400A has run out without removing the cleaning cartridge 500 from the housing 600. Furthermore, the color of the wiping member 400A and the color of the outer surface of the driven shaft 501 may be different. For example, if the wiping member 400A is white and the outer surface of the driven shaft 501 is red, then when the wiping member 400A is still present, the white member will be visible through the window 601, but when the wiping member 400A is gone, the red member will be visible through the window 601. This makes it easier for the user to recognize when the wiping member 400A is gone.

[0073] As shown in Figure 18, an operating section 602 for feeding the wiping member 400A is provided on the upper rear side of the housing 600. The operating section 602 protrudes upward from the top surface of the housing 600 and consists of a rotary knob that can be grasped and rotated by the user with their fingers. As shown in Figure 20, the lower part of the operating section 602 is rotatably supported around an axis F that extends vertically relative to the housing 600. Axis F is shown virtually, unlike the driven axis 501 and the drive axis 502. Axis F is parallel to the driven axis 501 and the drive axis 502.

[0074] As shown in Figure 21, the upper surface of the operating unit 602 is provided with a direction indicator 602a that indicates the direction of rotation of the operating unit 602 and a stop position indicator 602b that indicates the stop position of the operating unit 602. The direction indicator 602a is composed of, for example, an arrow. The stop position indicator 602b indicates to the user that the operating unit 602 should be rotated until the stop position indicator 602b is in a predetermined position, and is provided only on a part of the circumferential direction of the operating unit 602.

[0075] As shown in Figure 20, a reverse rotation prevention structure 610 is provided on the lower part of the operating section 602 to prevent reverse rotation of the operating section 602. The reverse rotation prevention structure 610 is composed of, for example, a running surface. The running surface has a plurality of movable teeth (not shown) formed on the lower surface of the operating section 602 so as to be arranged around the axis F, and a plurality of fixed teeth (not shown) formed on the part of the housing 600 opposite to the movable teeth. The shape setting of each tooth allows the operating section 602 to rotate (forward) in the feeding direction of the wiping member 400A, but prevents it from rotating (reverse) when an attempt is made to rotate the operating section 602 in the opposite direction to the feeding direction of the wiping member 400A by the movable teeth engaging with the fixed teeth. The reverse rotation prevention structure 610 only needs to prevent reverse rotation of the operating section 602, so it can be realized using various structures other than a running surface.

[0076] A drive gear 611 (also shown in Figure 22) is fixed to the operating unit 602. The drive gear 611 is positioned below the anti-reverse rotation structure 610 and rotates around axis F in conjunction with the rotation operation of the operating unit 602. On the other hand, a driven gear 612 that meshes with the drive gear 611 is positioned above the drive shaft 502. A connecting member 613 (shown in Figure 20) is inserted and fixed inside the upper part of the drive shaft 502, connecting the driven gear 612 and the drive shaft 502 so that they cannot rotate relative to each other. As shown in Figure 22, the number of teeth of the driven gear 612 is set to be greater than the number of teeth of the drive gear 611, and therefore the outer diameter of the driven gear 612 is larger than the outer diameter of the drive gear 611. The width of the housing 600 in the left-right direction is set so that the drive gear 611 with a large outer diameter can be accommodated.

[0077] When the operating unit 602 is rotated forward, the drive gear 611 also rotates in the same direction. As a result, the driven gear 612, which is meshed with the drive gear 611, rotates in the direction indicated by arrow H in Figure 22, and the drive shaft 502, which is fixed to this driven gear 612, also rotates in the direction indicated by arrow H. As shown in Figure 19, when the drive shaft 502 rotates in the direction indicated by arrow H, it winds up the wiping member 400A, so on the side facing the print head 22 (the rear side of the cleaning unit 400), the wiping member 400A moves from right to left, that is, in a direction perpendicular to the direction in which the multiple nozzles are lined up. In this embodiment, the feed amount of the wiping member 400A is set so that when the operating unit 602 is rotated once, the deposits on the nozzle group 22a are removed. Therefore, by rotating the operating unit 602 once, the predetermined cleaning operation can be completed.

[0078] The moving mechanism 600A for moving the wiping member 400A includes a drive gear 611, a driven gear 612, and a drive shaft 502. The drive gear 611 is a member that rotates in synchronization with the rotation of the operating unit 602. Therefore, the moving mechanism 600A is configured to operate in conjunction with the operation of the operating unit 602.

[0079] When moving the wiping member 400A from right to left, keeping the wiping member 400A in contact with the nozzle group 22a ensures that any deposits adhering to the nozzle group 22a are reliably wiped away. In this embodiment, with the cleaning unit 400 attached to the print head 22, a contact mechanism 600B is also provided to move the wiping member 400A toward the nozzle group 22a and bring it into contact with the nozzle group 22a. Therefore, the moving mechanism 600A wipes away any deposits adhering to the nozzle group 22a by moving the wiping member 400A from right to left while the wiping member 400A is in contact with the nozzle group 22a by the contact mechanism 600B.

[0080] Figure 23 is a rear perspective view of the cleaning unit 400 with the wiping member 400A removed. When the wiping member 400A is removed, the contact mechanism 600B becomes visible. The contact mechanism 600B has a bumper member 620 that contacts the wiping member 400A from the side opposite to the nozzle group 22a and presses the wiping member 400A against the nozzle group 22a. The bumper member 620 is provided in the housing 600 so that when the cleaning cartridge 500 is housed in the housing 600, it is inserted into the side of the wiping member 400A opposite to the nozzle group 22a.

[0081] The bumper member 620 includes an elastic material 621 positioned corresponding to the nozzle group 22a. The elastic material 621 is a member for pressing the wiping member 400A from the opposite side of the nozzle group 22a, and is made of a foamed material such as a sponge. The vertical position of the elastic material 621 is set to be the same as the vertical position of the nozzle group 22a when the cleaning unit 400 is attached to the print head 22. The vertical dimension of the elastic material 621 is set to be greater than or equal to the dimension from the upper end to the lower end of the nozzle group 22a.

[0082] In the pre-wiping state, the portion of the wiping member 400A facing the print head 22 is positioned in a predetermined standby position relative to the housing 600. In other words, when the cleaning unit 400 is in contact with the front surface 201 of the print head 22 where the nozzle group 22a is formed, the wiping member 400A is housed inside the housing 600 in a predetermined standby position relative to the nozzle group 22a. When the portion of the wiping member 400A facing the print head 22 is in the standby position, it is either away from the nozzle group 22a or slightly in contact with the nozzle group 22a. By setting the standby position in this way, when attaching the cleaning unit 400 to the print head 22 or removing the cleaning unit 400 from the print head 22, the wiping member 400A does not come into strong contact with the nozzle group 22a, thereby protecting the nozzle group 22a. On the other hand, even if the wiping member 400A is moved while the part of the wiping member 400A facing the print head 22 is in the standby position, little effect can be expected in wiping off the attached material.

[0083] In response to this, the contact mechanism 600B of this embodiment is configured to move the wiping member 400A from the standby position toward the nozzle group 22a by a predetermined amount and bring it into contact with the nozzle group 22a with a predetermined pressing force, and to move the wiping member 400A that has come into contact with the nozzle group 22a toward the nozzle group 22a by the predetermined amount and return it to the standby position.

[0084] The specific structure of the contact mechanism 600B will now be described. As shown in Figure 19, guide plates 620a extending in the front-rear direction are provided on both the left and right sides of the bumper member 620. Inside the housing 600, left and right guide sections 623 are provided to guide the guide plates 620a in the front-rear direction, and the left and right guide plates 620a are positioned between the left and right guide sections 623.

[0085] The contact mechanism 600B includes an input member 625. The input member 625 is located on the side of the bumper member 620 opposite to the elastic material 621, and between the left and right guided plates 620a. The input member 625 is a vertically elongated member and is fixed to the bumper member 620. The left-right middle portion of the input member 625 is composed of a curved portion 625a that curves toward the rear.

[0086] The contact mechanism 600B includes an input shaft 626. As shown in Figure 20, the input shaft 626 extends vertically and is arranged coaxially with axis F. The upper part of the input shaft 626 is fixed to the lower part of the operating unit 602, and the rotational force of the operating unit 602 is input to the input shaft 626, causing the operating unit 602 and the input shaft 626 to rotate synchronously at a constant speed.

[0087] The contact mechanism 600B includes an upper cam plate 627 and a lower cam plate 628. As shown in Figure 24, the lower cam plate 628 is fixed to the lower part of the input shaft 626 and is made of a plate material extending in a direction perpendicular to the shaft F. A lower cam groove 628a is formed on the upper surface of the lower cam plate 628 so as to surround the shaft F. The lower cam groove 628a is annular in shape and has a portion that is close to the shaft F and a portion that is far from the shaft F.

[0088] The lower portion of the input member 625 is provided with a lower driven portion 625b that protrudes downward and is inserted into the lower cam groove 628a. When the input shaft 626 is rotated, the lower cam plate 628 rotates, and a force corresponding to the shape of the lower cam groove 628a is input to the lower driven portion 625b which is inserted into the lower cam groove 628a. Because the lower cam groove 628a has a portion that is close to the shaft F and a portion that is far from the shaft F, a force in the front-rear direction is input to the lower driven portion 625b. As a result, the force in the front-rear direction is transmitted to the bumper member 620 via the input member 625. The bumper member 620 moves with the guided plate 620a being guided in the front-rear direction by the guide portion 623.

[0089] As shown in Figure 20, the upper cam plate 627 is configured similarly to the lower cam plate 628, fixed to the upper part of the input shaft 626 while positioned above the upper plate portion 504, and extending in a direction perpendicular to the shaft F. An upper cam groove 627a is formed on the lower surface of the upper cam plate 627 so as to surround the shaft F, and the shape of this upper cam groove 627a is identical to that of the lower cam groove 628a in the circumferential direction. Furthermore, the upper cam groove 627a and the lower cam groove 628a are in phase. The upper driven portion 625c, which is provided on the upper part of the input member 625, is inserted into the upper cam groove 627a. As a result, the upper part of the input member 625 is subjected to the same force in the same direction and at the same timing as the lower part, so that the bumper member 620 moves in a stable state.

[0090] As described above, when the user rotates the operating unit 602, the bumper member 620 can be moved in the front-rear direction by the rotation of the upper cam plate 627 and the lower cam plate 628. By moving the bumper member 620 forward and away from the nozzle group 22a, the wiping member 400A can be kept in a standby position. By moving the bumper member 620, which is located in the front, backward and closer to the nozzle group 22a, the wiping member 400A, which is in the standby position, can be moved by a predetermined amount toward the nozzle group 22a and brought into contact with the nozzle group 22a. At this time, the elastic material 621 of the bumper member 620 is compressed in the front-rear direction and undergoes elastic deformation, so the repulsive force of the elastic material 621 can be used to bring the wiping member 400A into close contact with the nozzle group 22a. In other words, the forward and backward movement of the bumper member 620, defined by the rotation of the upper cam plate 627 and the lower cam plate 628, brings the wiping member 400A and the nozzle group 22a closer together to a position where they make contact. The amount of elastic deformation of the elastic material 621 of the bumper member 620 allows for fine adjustment of the relative position of the wiping member 400A and the nozzle group 22a. That is, the elastic material 621 absorbs the effects of dimensional tolerances of each component and the surrounding vibration environment, playing a role in ensuring that the wiping member 400A is in close contact with the nozzle group 22a.

[0091] The pressing force of the wiping member 400A against the nozzle group 22a can be set by the shape of the upper cam groove 627a and the lower cam groove 628a. In this embodiment, the pressing force of the wiping member 400A is set so that the wiping member 400A can be reliably brought into contact with the nozzle group 22a without placing an excessive load on the nozzle group 22a. When the operating unit 602 is rotated further, the bumper member 620 moves forward, returning the wiping member 400A to the standby position. During one rotation of the operating unit 602, the bumper member 620, which is in the standby position, switches to the contact position, and then returns to the standby position.

[0092] The contact mechanism 600B is configured to operate in conjunction with the operation of the control unit 602. Since both the contact mechanism 600B and the movement mechanism 600A operate in conjunction with the operation of the control unit 602, the operation of the contact mechanism 600B and the operation of the movement mechanism 600A can be mechanically synchronized.

[0093] As shown in Figure 20, the housing 600 is equipped with a first locking mechanism 600C that restricts the operation of the operating section 602 until the cleaning unit 400 is attached to the front end surface of the print head 22. Figures 25 and 26 show the structure of the first locking mechanism 600C. The first locking mechanism 600C comprises a rotating member 630 that rotates integrally with the operating section 602, a reciprocating member 631 that moves linearly relative to the housing 600 in the front-rear direction, and a locking gear 632. The rotating member 630 is an annular shape that surrounds the upper cam plate 627 and is fixed to the upper cam plate 627. The rotation center of the rotating member 630 is located on axis F. A recess 630a that is recessed radially inward is formed at one point in the circumferential direction of the rotating member 630. The rotating member 630 rotates in sync with the operating section 602.

[0094] The locking gear 622 is positioned above the upper plate portion 504 and fixed to the upper part of the driven shaft 501. The height position of the locking gear 622 and the height position of the rotating member 630 are set to be the same.

[0095] The reciprocating member 631 is positioned above the upper plate portion 504 at the same height position as the rotating member 630. A first tension spring 633 is provided on the side of the reciprocating member 631. One end of the first tension spring 633 is fixed to the upper plate portion 504, while the other end is fixed to the reciprocating member 631. The first tension spring 633 constantly applies a biasing force to the reciprocating member 631 in a rearward direction.

[0096] First through-holes 600a are formed on both the left and right sides of the rear surface of the housing 600. A projection 631a is provided at the rear of the reciprocating member 631, which is inserted into the first through-hole 600a. When the reciprocating member 631 is positioned at the rear due to the biasing force of the first tension spring 633, the projection 631a protrudes from the first through-hole 600a to the rear by a predetermined dimension or more (shown in Figure 25). On the other hand, when a forward pressing force is applied to the projection 631a that protrudes to the rear from the first through-hole 600a, the reciprocating member 631 moves forward against the biasing force of the first tension spring 633 (shown in Figure 26).

[0097] A first locking piece 631b, projecting rearward, is formed at the intermediate portion of the reciprocating member 631 in the front-rear direction, corresponding to the rotating member 630. The first locking piece 631b is positioned in front of the rotating member 630, and as shown in Figure 25, when the reciprocating member 631 is in the rear position, it fits into the recess 630a of the rotating member 630, locking the rotating member 630 from rotating. On the other hand, as shown in Figure 26, when the reciprocating member 631 is in the front position, the first locking piece 631b disengages from the recess 630a of the rotating member 630, allowing the rotating member 630 to rotate.

[0098] Furthermore, a second locking piece 631c is formed on the front side of the reciprocating member 631, projecting backward and corresponding to the locking gear 622. The second locking piece 631c is positioned in front of the locking gear 622, and as shown in Figure 25, when the reciprocating member 631 is in the rear position, it engages with the teeth of the locking gear 622, locking it so that the locking gear 622 does not rotate. On the other hand, as shown in Figure 26, when the reciprocating member 631 is in the front position, the second locking piece 631c disengages from the teeth of the locking gear 622, allowing the locking gear 622 to rotate.

[0099] When the cleaning unit 400 is removed from the print head 22, the protruding portion 631a of the retractable member 631 is no longer pushed from the outside, and therefore protrudes from the first through hole 600a by a predetermined dimension or more. As a result, as shown in Figure 25, the rotation of the rotating member 630 and the locking gear 622 is locked by the retractable member 631.

[0100] When the cleaning unit 400 is attached to the print head 22, the protruding portion 631a protruding from the first through hole 600a is pushed by the front end surface of the print head 22, causing the reciprocating member 631 to move forward as shown in Figure 26. This allows the rotating member 630 and the locking gear 622 to rotate. In this way, by providing the first locking mechanism 600C, the operating unit 602 cannot be operated when the cleaning unit 400 is removed from the print head 22, thus preventing the wiping member 400A from being wasted.

[0101] The housing 600 includes a second locking mechanism 600D that restricts the operation of the operating unit 602 once a predetermined cleaning operation is completed with the cleaning unit 400 attached to the front end surface of the print head 22. Figures 27 to 30 show the structure and operation of the second locking mechanism 600D. The second locking mechanism 600D includes a claw portion 640 provided on the upper part of the drive gear 611, a locking portion 641 that engages with the claw portion 640, and a movable member 642 that moves the locking portion 641. The claw portion 640 protrudes radially outward, so that the upper part of the drive gear 611 has a shape in which a part in the circumferential direction protrudes radially. The claw portion 640 rotates in synchronization with the operating unit 602.

[0102] The locking portion 641 is positioned in front of the claw portion 640 and is formed to protrude toward the rear. The locking portion 641 is attached to the movable member 642 and supported by the movable member 642. As shown in Figure 27, when the locking portion 641 abuts against the claw portion 640 from one side in the circumferential direction, the rotation of the drive gear 611, that is, the rotation of the operating portion 602, is locked.

[0103] The movable member 642, which supports the locking portion 641, is positioned above the upper plate portion 504 and is a member that moves linearly relative to the housing 600 in the front-rear direction. A second tension spring 643 is provided on the side of the movable member 642. One end of this second tension spring 643 is fixed to the upper plate portion 504, while the other end is fixed to the movable member 642. The second tension spring 643 constantly applies a biasing force toward the movable member 642.

[0104] The rear surface of the housing 600 has second through holes 600b (shown in Figure 18, etc.) formed on both the left and right sides. The rear end of the movable member 642 is provided with a projection 642a that is inserted into the second through hole 600b. When the movable member 642 is positioned to the rear due to the biasing force of the second tension spring 643, the projection 642a protrudes from the second through hole 600b to the rear by a predetermined dimension or more (shown in Figure 27). On the other hand, when a forward pressing force is applied to the projection 642a that protrudes to the rear from the second through hole 600b, the movable member 642 moves forward against the biasing force of the second tension spring 643 (shown in Figure 28).

[0105] A locking portion 641 is attached to the movable member 642, and the locking portion 641 moves in conjunction with the movable member 642. The locking portion 641 is biased to the right by a biasing member 645. As shown in Figure 28, when the movable member 642 moves forward, the locking portion 641 also moves forward and separates from the claw portion 640. This is the unlocking process. When the cleaning unit 400 is attached to the print head 22, the protruding portion 642a protruding from the second through hole 600b is pushed forward by the release surface 230b (shown in Figure 14), which is part of the front end surface of the upper cover 230. As the protruding portion 642a is pushed by the release surface 230b, the movable member 642 and the claw portion 640 move forward as shown in Figure 28. This enables the rotation of the drive gear 611, i.e., the rotation of the operating portion 602.

[0106] When the cleaning unit 400 moves below the release surface 230b and reaches the correct mounting position, the protruding portion 642a and the release surface 230b become separated in the vertical direction, so the movable member 642 moves to the rear as shown in Figure 29, and the locking portion 641 also moves to the rear as a result. In the preceding stage, that is, at the moment of transition from the state shown in Figure 27 to the state shown in Figure 28, the locking portion 641 moves to the right of the claw portion 640 due to the biasing force of the biasing member 645. Therefore, even though the locking portion 641 moves to the rear as shown in Figure 29, it does not engage with the claw portion 640 and remains in the unlocked state.

[0107] When the user rotates the operating unit 602, causing the drive gear 611 to rotate, the pawl portion 640 also rotates. While the pawl portion 640 is rotating, the locking portion 641 slides along the upper outer surface of the drive gear 611. Eventually, when the rotation angle of the operating unit 602 approaches 360°, as shown in Figure 30, the pawl portion 640 contacts and locks against the locking portion 641, preventing the operating unit 602 from rotating more than one full turn. This ensures that anyone performing the cleaning can always use the required amount of the wiping material 400A to perform the same cleaning operation, eliminating reliance on individual expertise and preventing wasteful use of the wiping material 400A.

[0108] When removing the cleaning unit 400 from the print head 22, the protruding portion 642a protruding from the second through-hole 600b comes into contact with the release surface 230b, which is part of the front end surface of the upper cover 230, and is pushed forward, releasing the lock as shown in Figure 28. Therefore, when using the cleaning unit 400 again, the operating section 602 can be rotated.

[0109] As shown in Figures 31 and 32, the housing 600 includes a third locking mechanism 600E that restricts the cleaning unit 400 from detaching from the front end surface of the print head 22 until the cleaning unit 400 is attached to the front end surface of the print head 22 and has completed a predetermined cleaning operation. The third locking mechanism 600E includes a locking cam plate 660 and a locking pin 661. The locking cam plate 660 is positioned above the upper plate portion 504 and is fixed to the lower part of the operating portion 602. The locking cam plate 660 is made of a plate material extending in a direction perpendicular to the axis F and rotates in synchronization with the operating portion 602. Because the operating portion 602 can only be rotated once by the second locking mechanism 600D, the locking cam plate 660 also rotates only once.

[0110] A locking cam groove 660a is formed on the upper surface of the locking cam plate 660 so as to surround the shaft F. The locking cam groove 660a is annular in shape and has a portion that is close to the shaft F and a portion that is far from the shaft F.

[0111] A third through-hole 600c is formed in the rear surface of the housing 600 in the middle of the left-right direction. The lock pin 661 is positioned above the locking cam plate 660. The rear portion of the lock pin 661 is positioned above the upper plate portion 504 and is provided so as to be able to protrude rearward from the third through-hole 600c, and moves linearly relative to the housing 600 in the front-rear direction. The front portion of the lock pin 661 is formed so as to protrude downward, into which a driven portion 661a is inserted into the locking cam groove 660a. When the operating portion 602 is rotated to rotate the locking cam plate 660, a force corresponding to the shape of the locking cam groove 660a is applied to the driven portion 661a inserted into the locking cam groove 660a. Because the locking cam groove 660a has a portion that is close to the axis F and a portion that is far from the axis F, a force in the front-rear direction is applied to the driven portion 661a. This allows the lock pin 661 to move in the front-to-back direction, switching between a locked position where the rear portion of the lock pin 661 protrudes significantly from the third through-hole 600c, as shown in Figure 32, and an unlocked position where the rear portion of the lock pin 661 hardly protrudes from the third through-hole 600c, as shown in Figure 31. The timing of the switch to the unlocked position coincides with the completion of a predetermined cleaning operation and is synchronized with the second lock mechanism 600D.

[0112] As shown in Figures 14 and 15, an insertion hole 22f is formed on the front end surface of the print head 22 into which the rear portion of the lock pin 661 is inserted. The position of the insertion hole 22f coincides with the position of the third through hole 600c of the cleaning unit 400 when it is attached to the print head 22. Therefore, as shown in Figure 32, when the lock pin 661 is switched to the locked position, the rear portion of the lock pin 661 is inserted into the insertion hole 22f, preventing the cleaning unit 400 from moving upward, and thus preventing the cleaning unit 400 from being removed. On the other hand, when the lock pin 661 is switched to the unlocked position, the rear portion of the lock pin 661 comes out of the insertion hole 22f, allowing the cleaning unit 400 to move upward, and thus the cleaning unit 400 can be removed. In other words, the cleaning unit 400 cannot be removed until the operating unit 602 is rotated one full turn, so the cleaning unit 400 will not be accidentally removed during cleaning.

[0113] As shown in Figure 20, the cleaning unit 400 incorporates a magnet 670 that is linked to the operating unit 602. The magnet 670 is fixed to the upper cam plate 627 and moves from a position close to the rear surface of the housing 600 to a position further away from the rear surface of the housing 600, and then moves from a position further away from the rear surface of the housing 600 to a position close to the rear surface of the housing 600, as the upper cam plate 627 rotates.

[0114] As shown in Figures 14 and 15, a Hall element (detection unit) 22e is provided near the front end surface of the print head 22 to detect the state of the cleaning unit 400 based on the magnetic force of the magnet 670. If the Hall element 22e detects a magnetic force above a predetermined level, it is determined that the cleaning unit 400 is properly attached to the print head 22. On the other hand, if the Hall element 22e does not detect a magnetic force above a predetermined level, it is determined that the cleaning unit 400 is abnormal. This determination unit may be composed of the control unit 40 of the controller 4, or it may be built into the drawing machine body 25. If it is determined that the cleaning unit 400 is abnormal, the user can be notified. Furthermore, it is also possible to determine whether cleaning is in progress based on the detection result of the Hall element 22e.

[0115] As shown in Figure 11, etc., the housing 600 is provided with a dial 680 for removing slack from the wiping member 400A. A portion of the dial 680 in the circumferential direction is exposed from the front surface of the housing 600, and this portion of the dial 680 in the circumferential direction can be operated by the user from outside the housing 600.

[0116] The dial 680 is fixed to the upper part of the driven shaft 501. If the wiping member 400A is loose, the user can rotate the dial 680 from the outside, which will rotate the driven shaft 501 in the winding direction of the wiping member 400A and remove the slack in the wiping member 400A.

[0117] The positioning of the wiping member 400A relative to the nozzle group 22a will be described in detail. The housing 600 of the cleaning unit 400 has a wiping surface in which the wiping member 400A is exposed, at least when pushed out by the contact mechanism. The wiping surface is provided with a rail portion 401, a movable member 642, and a reciprocating member 631. The user holds the housing 600 of the cleaning unit 400 by hand and brings the wiping surface of the housing 600 into contact with the front surface 201 of the print head 22. The cleaning unit 400 is configured such that the wiping member 400A is positioned and held at least in the front-rear direction relative to the wiping surface. Therefore, when the wiping surface of the housing 600 is in contact with the front surface 201 of the print head 22, the wiping member 400A is positioned at least in the front-rear direction relative to the nozzle group 22a formed on the front surface 201. In this way, by designing the cleaning unit 400 in a way that allows for mechanical positioning in the front-to-back direction, the user can manually clean the nozzle group 22a precisely without misjudging the amount of force to apply when pressing the wiping member 400A against the nozzle group 22a.

[0118] The embodiments described above are merely illustrative in all respects and should not be interpreted restrictively. Furthermore, any modifications or changes that fall within the equivalent scope of the claims are all within the scope of the present invention. [Industrial applicability]

[0119] As described above, this disclosure can be used to remove deposits adhering to a group of nozzles. [Explanation of Symbols]

[0120] 2 drawing machine 20a Ink Tank 22 printheads 22a Nozzle group 22e Hall element 27 Purge Control Unit 240 absorbent 245 trays 400 Cleaning Units 400A Wiping Member 602 Operation section 600A Mobile Mechanism 600B Contact mechanism 600C First Locking Mechanism 600D Second Locking Mechanism 600E Third Locking Mechanism 621 Elastic material 670 Magnets

Claims

1. A drawing machine that ejects ink for drawing information onto an object to be drawn on, which is transported by a conveyor, An ink tank that holds the ink, A print head for ejecting ink supplied from the aforementioned ink tank toward an object being transported, A group of nozzles consisting of multiple nozzles arranged in a row on one end face of the print head, A purge control unit that performs a purging process to release ink remaining in the flow path from the ink tank to the nozzle group to the outside via the nozzle group, A drawing machine comprising: a cleaning unit having a wiping member for wiping off deposits adhering to the nozzle group by the purging process, and positioning the wiping member relative to the nozzle group while in contact with one end surface of the print head.

2. In the drawing machine described in claim 1, The cleaning unit is A drawing machine that positions the wiping member relative to the nozzle group while in contact with one end face of the print head via manual operation by the user.

3. In the drawing machine according to claim 2, The cleaning unit is A drawing machine that is detachably attached to the print head via manual operation by the user, and which contacts one end face of the print head when attached to the print head.

4. In the drawing machine according to claim 1, The cleaning unit is A contact mechanism, while attached to the print head, moves the wiping member toward the nozzle group and brings it into contact with the nozzle group, A drawing machine comprising: a moving mechanism that, while the wiping member is in contact with the nozzle group by the contact mechanism, moves the wiping member in a direction perpendicular to the direction in which the plurality of nozzles are aligned, thereby wiping off any deposits adhering to the nozzle group.

5. In the drawing machine according to claim 1, An elastic material that presses the wiping member from the opposite side of the nozzle group, A drawing machine comprising a contact mechanism that moves the wiping member toward the nozzle group and brings it into contact with the nozzle group while it is attached to the print head.

6. In the drawing machine according to claim 2, The cleaning unit comprises a housing that accommodates the contact mechanism, The wiping member is positioned at a predetermined standby position relative to the housing, The contact mechanism is a drawing machine that moves the wiping member by a predetermined amount from the standby position toward the nozzle group and brings it into contact with the nozzle group, and moves the wiping member that has come into contact with the nozzle group by the predetermined amount toward away from the nozzle group and returns it to the standby position.

7. In the drawing machine according to claim 6, The housing is provided with an operating unit for feeding the wiping member, A drawing machine in which at least one of the contact mechanism and the moving mechanism is configured to operate in conjunction with the operation of the control unit.

8. In the drawing machine according to claim 7, A drawing machine comprising a first locking mechanism that restricts the operation of the operating section until the cleaning unit is attached to one end face of the print head.

9. In the drawing machine according to claim 7, A drawing machine comprising a second locking mechanism that restricts the operation of the control unit when a predetermined cleaning operation is completed with the cleaning unit attached to one end face of the print head.

10. In the drawing machine according to claim 7, A drawing machine comprising a third locking mechanism that restricts the cleaning unit from detaching from one end face of the print head until a predetermined cleaning operation is completed while the cleaning unit is attached to one end face of the print head.

11. In the drawing machine according to claim 1, An absorbent body for absorbing ink leaked from the nozzle group due to the purging process, A tray is provided below the nozzle group to guide the ink leaked from the nozzle group to the absorbent, A drawing machine equipped with the following features.

12. In the drawing machine according to claim 1, A sliding portion is formed on one end face of the print head, extending in the direction of the arrangement of the nozzle group. The cleaning unit is mounted to the print head so as to slide against the sliding portion of the print head in the direction of the alignment of the nozzle group, in a drawing machine.

13. In the drawing machine according to claim 7, The cleaning unit incorporates a magnet that is linked to the operating unit, A drawing machine comprising a detection unit that detects the state of the cleaning unit based on the magnetic force of the aforementioned magnet.

14. A cleaning unit that is detachably attached to a drawing machine comprising: an ink tank for containing ink; a print head for ejecting ink supplied from the ink tank toward an object to be drawn while being transported; a nozzle group consisting of a plurality of nozzles arranged in a line on one end face of the print head; and a purge control unit that performs a purge process to leak ink remaining in the flow path from the ink tank to the nozzle group to the outside through the nozzle group, A wiping member for wiping off deposits adhering to the nozzle group by the purging process, A cleaning unit comprising a mounting portion that is detachably attached to one end face of the print head on which the nozzle group is arranged, and for positioning the wiping member relative to the nozzle group.

15. In the cleaning unit according to claim 14, A contact mechanism, while attached to the print head, moves the wiping member toward the nozzle group and brings it into contact with the nozzle group, A cleaning unit comprising: a moving mechanism that, while the wiping member is in contact with the nozzle group by the contact mechanism, moves the wiping member in a direction perpendicular to the direction in which the plurality of nozzles are aligned, thereby wiping off any deposits adhering to the nozzle group.

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