JP2021104668A - Ink jet printer - Google Patents

Abstract

To solve the problem that ink is hardly supplied to an ink head in a state of being precipitated inside an ink tank.SOLUTION: In a printer 100, an ink tank 71 and an ink head 41 are connected to each other by a first forward flow path 81a, a second forward flow path 81b, and a third forward flow path 81c. Further, the ink tank 71 and the second forward flow path 81b are connected to each other by a return flow path 83. A liquid feed pump 73 is connected to the first forward flow path 81a and the second forward flow path 81b. A negative-pressure open valve mechanism 171 is connected to the third forward flow path 81c and the ink head 41. The negative-pressure open valve mechanism 171 has a second negative- pressure open ink chamber 174. The negative-pressure open valve mechanism 171 is configured to be open when pressure inside the second negative-pressure open ink chamber 174 is a prescribed open pressure or lower.SELECTED DRAWING: Figure 4

Description

The present invention relates to an inkjet printer.

Conventionally, an inkjet printer including an ink head having a nozzle for ejecting ink and an ink tank in which ink to be supplied to the ink head is stored has been known (see Patent Document 1). In this type of inkjet printer, printing is performed on the medium by ejecting ink from the nozzle of the ink head toward the medium.

In the inkjet printer disclosed in Patent Document 1, the ink head and the ink tank are usually connected by a flow path. The normal flow path is provided with a damper that supplies ink supplied from the ink tank to the ink head while suppressing pressure fluctuations, and a feed pump. Further, the damper is provided with a discharge port, and a circulation flow path is connected to the discharge port and the normal flow path. As described above, in the inkjet printer disclosed in Patent Document 1, ink is circulated in the flow path between the ink tank and the ink head.

Japanese Unexamined Patent Publication No. 2014-94460

By the way, in the inkjet printer disclosed in Patent Document 1, as described above, ink is circulated in the flow path between the ink tank and the ink head. In this case, since the ink in the flow path circulates, it is possible to prevent the ink from settling in the flow path. However, the ink in the ink tank can settle. Therefore, the precipitated ink may be supplied from the ink tank to the ink head, which may deteriorate the print quality.

The present invention has been made in view of this point, and an object of the present invention is to provide an inkjet printer in which the ink in the ink tank is difficult to be supplied to the ink head in a precipitated state.

The inkjet printer according to the present invention includes an ink tank, an ink head, a first forward flow path, a liquid feed pump, a second forward flow path, a third forward flow path, a negative pressure release valve mechanism, and a return flow path. , Is equipped. The ink tank stores ink. The ink head has a nozzle for ejecting ink. One end of the first forward flow path is connected to the ink tank. The liquid feed pump is connected to the other end of the first forward flow path. One end of the second forward flow path is connected to the liquid feed pump. One end of the third forward flow path is connected to the other end of the second forward flow path. The negative pressure release valve mechanism is connected to the other end of the third forward flow path and communicates with the nozzle. One end of the return flow path is connected to the other end of the second forward flow path, and the other end is connected to the ink tank. The negative pressure release valve mechanism includes a first inflow path, a first negative pressure release ink chamber, a second negative pressure release ink chamber, a first outflow path, and a first valve body. One end of the first inflow path is connected to the other end of the third forward flow path. The first negative pressure release ink chamber is formed with a first inflow port to which the other end of the first inflow path is connected. The second negative pressure opening ink chamber communicates with the first negative pressure opening ink chamber through a communication port, and a first outlet is formed. One end of the first outflow path is connected to the first outlet, and the other end communicates with the nozzle. The first valve body is provided so that the communication port can be opened and closed, and opens the communication port when the pressure of the second negative pressure opening ink chamber is equal to or lower than a predetermined negative pressure opening pressure.

According to the inkjet printer, when the pressure in the second negative pressure release ink chamber is higher than the predetermined opening pressure, the negative pressure release valve mechanism is closed, so that the ink in the ink tank is driven by the liquid feed pump. It returns to the ink tank through the first forward flow path, the second forward flow path, and the return flow path. Therefore, when the pressure in the second negative pressure open ink chamber is higher than the open pressure, the ink circulates including the ink tank, so that the ink is agitated and the ink is less likely to settle. In this state, when ink is ejected from the nozzle of the ink head and the pressure in the second negative pressure release ink chamber becomes equal to or lower than the opening pressure, the negative pressure release valve mechanism is opened. Therefore, the agitated ink in the ink tank can be supplied to the ink head. Therefore, it is possible to make it difficult for the ink in the ink tank to be supplied to the ink head in a precipitated state.

According to the present invention, it is possible to provide an inkjet printer in which the ink in the ink tank is difficult to be supplied to the ink head in a precipitated state.

FIG. 1 is a front view showing an inkjet printer according to the first embodiment. FIG. 2 is a diagram schematically showing the configuration of the lower surface of the carriage. FIG. 3 is a block diagram showing the relationship between the ink head and the ink supply system. FIG. 4 is a schematic view showing the configuration of the ink supply system. FIG. 5 is a perspective view of the relief valve. FIG. 6 is a cross-sectional view of the relief valve in the VI-VI line of FIG. 5, and is a diagram showing a first state. FIG. 7 is a diagram corresponding to FIG. 6 showing the first state. FIG. 8 is a diagram corresponding to FIG. 6 showing the second state. FIG. 9 is a diagram corresponding to FIG. 6 showing the second state. FIG. 10 is a cross-sectional view of the relief valve, and is a view corresponding to FIG. 6 showing a state in which the button is moved upward. FIG. 11 is a perspective view of the damper. FIG. 12 is a front view of the damper. FIG. 13 is a cross-sectional view of the damper taken along the line XIII-XIII of FIG. 12, showing a state in which the negative pressure release valve mechanism is closed and the pressure release valve mechanism is open. FIG. 14 is a view corresponding to FIG. 13 showing a state in which the negative pressure release valve mechanism is open and the pressure release valve mechanism is closed. FIG. 15 is a view corresponding to FIG. 13 showing a state in which both the negative pressure release valve mechanism and the pressure release valve mechanism are closed. FIG. 16 is a front view of the cap unit. FIG. 17 is a front view of the wiper mechanism. FIG. 18 is a block diagram of the printer. FIG. 19 is a schematic view showing a state of the ink supply system during the printing operation. FIG. 20 is a schematic view showing a state of the ink supply system during the printing operation. FIG. 21 is a schematic view showing a state of the ink supply system during the first cleaning operation and the third cleaning operation. FIG. 22 is a schematic view showing a state of the ink supply system during the second cleaning operation and the third cleaning operation. FIG. 23 is a schematic view showing a state of the ink supply system during the wiping operation. FIG. 24 is a schematic view showing a state of the ink supply system during the circulation operation. FIG. 25 is a schematic view showing a state of the ink supply system during the circulation operation. FIG. 26 is a schematic view showing a state of the ink supply system during the maintenance operation. FIG. 27 is a front view of the damper according to the second embodiment, and is a view corresponding to FIG. FIG. 28 is a cross-sectional view of the damper in line XXVIII-XXVIII of FIG. FIG. 29 is a perspective view of the damper according to the third embodiment. FIG. 30 is an enlarged perspective view of the foreign matter removing mechanism of the damper according to the third embodiment. FIG. 31 is a partial cross-sectional view of the damper in the XXXI-XXXI line of FIG.

Hereinafter, embodiments of the inkjet printer according to the present invention will be described with reference to the drawings. It should be noted that the embodiments described here are, of course, not intended to particularly limit the present invention.

<First Embodiment>
FIG. 1 is a front view of an inkjet printer (hereinafter referred to as a printer) 100 according to the present embodiment. In the following description, the reference numerals F, Rr, L, R, U, and D in the drawings mean front, rear, left, right, top, and bottom when the printer 100 is viewed from the front. The reference numeral Y in the drawing indicates the main scanning direction, and the reference numeral X in the drawing (see FIG. 2) indicates the sub-scanning direction. In the present embodiment, the main scanning direction Y is the left-right direction. The sub-scanning direction X is a front-rear direction, which is orthogonal to the main scanning direction Y in a plan view. However, these directions are merely the directions defined for convenience of explanation, and do not limit the installation mode of the printer 100 at all, nor do they limit the present invention at all.

The printer 100 prints on the medium 5. In the present embodiment, the medium 5 is a roll-shaped recording paper, which is a so-called roll paper. However, the medium 5 is not limited to the roll-shaped recording paper. For example, the medium 5 may be a resin sheet or film such as polyvinyl chloride or polyester, a plate material, a cloth such as a woven cloth or a non-woven fabric, or other medium, in addition to papers such as plain paper and printing paper for inkjet. good.

As shown in FIG. 1, the printer 100 includes a printer main body 10, a platen 13, a transport mechanism 20, a guide rail 15, a carriage 17, a head moving mechanism 30, and ink heads 41 to 44 (see FIG. 2). It includes an ink supply system 61 to 68 (see FIG. 3), a cap unit 110 (see FIG. 16), a wiper mechanism (see FIG. 17), and a control device 200.

The printer main body 10 has a casing extending in the main scanning direction Y. The platen 13 supports the medium 5. A medium 5 is supported on the platen 13, and printing is performed on the platen 13. The platen 13 extends in the main scanning direction Y and the sub-scanning direction X.

The transport mechanism 20 transports the medium 5 supported by the platen 13 in the sub-scanning direction X. The configuration of the transport mechanism 20 is not particularly limited. In the present embodiment, the transport mechanism 20 includes a pinch roller 21, a grit roller 22, and a feed motor 23. The pinch roller 21 is arranged above the platen 13 and below the guide rail 15 and presses the medium 5 from above. The grit roller 22 is provided on the platen 13 with its upper portion exposed upward from the platen 13. The grit roller 22 faces the pinch roller 21. The installation positions and numbers of the pinch rollers 21 and the grit rollers 22 are not particularly limited. In the present embodiment, as shown in FIG. 1, the pinch roller 21 and the grit roller 22 are arranged at the left end portion and the right end portion of the platen 13, respectively.

Here, the feed motor 23 is connected to the grit roller 22. When the feed motor 23 is driven with the medium 5 sandwiched between the pinch roller 21 and the grit roller 22, the grit roller 22 rotates. As a result, the medium 5 is conveyed in the sub-scanning direction X.

The guide rail 15 is arranged above the platen 13. The guide rail 15 is arranged parallel to the platen 13 and extends in the main scanning direction Y. A carriage 17 is engaged with the guide rail 15. The carriage 17 is slidably provided on the guide rail 15.

The head moving mechanism 30 is a mechanism for moving the carriage 17 and the ink heads 41 to 44 (see FIG. 2) in the main scanning direction Y. The configuration of the head moving mechanism 30 is not particularly limited. In the present embodiment, the head moving mechanism 30 includes left and right pulleys 31a and 31b, a belt 32, and a carriage motor 33. The left pulley 31a is provided in the vicinity of the left end portion of the guide rail 15. The right pulley 31b is provided near the right end of the guide rail 15. The belt 32 has, for example, an endless shape, and is wound around a left pulley 31a and a right pulley 31b. A carriage 17 is attached and fixed to the belt 32.

A carriage motor 33 is connected to the right pulley 31b. When the carriage motor 33 is driven, the right pulley 31b rotates, and the belt 32 travels between the left and right pulleys 31a and 31b. As a result, the carriage 17 and the ink heads 41 to 44 move along the guide rail 15 in the main scanning direction Y.

FIG. 2 is a diagram schematically showing the configuration of the lower surface of the carriage 17. As shown in FIG. 2, the ink heads 41 to 44 are provided on the carriage 17. The ink heads 41 to 44 are supported by the carriage 17 so that the lower surface thereof is exposed below the carriage 17. The ink heads 41 to 44 eject ink. The number of ink heads 41 to 44 is not particularly limited, but is four in the present embodiment. The four ink heads 41 to 44 are arranged side by side in the main scanning direction Y. In the following description, the ink heads 41 to 44 may be appropriately referred to as the first to fourth ink heads 41 to 44, respectively.

In the present embodiment, the ink heads 41 to 44 each have a nozzle surface 45. The nozzle surface 45 constitutes the lower surface of the ink heads 41 to 44 and faces the platen 13 (see FIG. 1). A plurality of nozzles 51 are formed side by side in the sub-scanning direction X, and a plurality of nozzles 52 are formed side by side in the sub-scanning direction X on the nozzle surface 45 of the first ink head 41. Similarly, on the nozzle surface 45 of the second ink head 42, a plurality of nozzles 53 are formed side by side in the sub-scanning direction X, and a plurality of nozzles 54 are formed side by side in the sub-scanning direction X. On the nozzle surface 45 of the third ink head 43, a plurality of nozzles 55 are formed side by side in the sub-scanning direction X, and a plurality of nozzles 56 are formed side by side in the sub-scanning direction X. Further, on the nozzle surface 45 of the fourth ink head 44, a plurality of nozzles 57 are formed side by side in the sub-scanning direction X, and a plurality of nozzles 58 are formed side by side in the sub-scanning direction X.

Here, the rows of each of the plurality of nozzles 51 to 58 are referred to as nozzle rows 51a to 58a, respectively. Each ink head 41-44 has two nozzle rows. However, the number of nozzle rows of each ink head 41 to 44 is not limited to two, and may be one or three or more.

FIG. 3 is a block diagram showing the relationship between the ink heads 41 to 44 and the ink supply systems 61 to 68. As shown in FIG. 3, the ink supply systems 61 to 68 are systems that supply ink to the ink heads 41 to 44. The ink supply systems 61 to 68 are provided for each nozzle row 51a to 58a. In the present embodiment, since the number of nozzle rows is eight, the number of ink supply systems 61 to 68 is also eight. Ink supply systems 61 to 68 are connected to the nozzle rows 51a to 58a, respectively. However, the ink supply systems 61 to 68 according to the present embodiment may not be provided for each of the nozzle rows 51a to 58a, and one ink supply system may be provided for a plurality of nozzle rows. That is, the plurality of nozzle rows may share one ink tank 71 (see FIG. 4), which will be described later. Here, the ink supply systems 61 to 68 all have the same configuration. Therefore, in the following, the ink supply system 61 connected to the plurality of nozzles 51 constituting the nozzle row 51a of the first ink head 41 will be described, and the description of the other ink supply systems 62 to 68 will be omitted as appropriate. In the ink supply systems 61 to 68, the configuration of some ink supply systems may be different from the configurations of other ink supply systems.

FIG. 4 is a schematic view showing the configuration of the ink supply systems 61 to 68. As shown in FIG. 4, the ink supply system 61 includes an ink tank 71, an ink flow path 72, a liquid feed pump 73, a relief valve 74, and a damper 75.

The ink tank 71 is a container in which ink is stored. The ink tank 71 has a structure capable of replenishing ink. Therefore, in the present embodiment, when the amount of ink stored in the ink tank 71 becomes small, the ink tank 71 is not replaced, but the ink tank 71 is newly replenished with ink. Further, in the present embodiment, air exists together with the ink inside the ink tank 71, and the ink tank 71 has a gas-liquid interface in which the ink and the air come into contact with each other. Further, the ink tank 71 has a structure in which the inside can be opened to the atmosphere. However, the ink tank 71 may be in the shape of a pouch. The ink tank 71 does not have to have a structure that can be opened to the atmosphere.

The ink tank 71 is formed with a tank inflow port 71a and a tank outflow port 71b. Although detailed illustration is omitted, the tank inflow port 71a is formed on the upper wall forming the upper surface of the ink tank 71. The tank outlet 71b is formed on, for example, a bottom wall forming the bottom surface of the ink tank 71.

In this embodiment, one ink tank 71 is provided for each ink supply system 61 to 68. The color of the ink stored in the ink tank 71 is not particularly limited. One ink tank 71 stores, for example, process color inks such as cyan ink, magenta ink, yellow ink, and black ink, and one ink of special color inks such as clear ink and white ink. Further, the ink material is not limited in any way, and various materials conventionally used as ink materials for inkjet printers can be used. The ink may be, for example, a solvent-based (solvent-based) pigment ink or a water-based pigment ink. Alternatively, it may be a water-based dye ink, an ultraviolet curable pigment ink that cures by receiving ultraviolet rays, or the like.

The ink flow path 72 connects the ink tank 71 and the ink head 41. In the ink supply system 61, the ink in the ink tank 71 is supplied to the nozzles 51 forming the nozzle row 51a of the ink head 41 through the ink flow path 72. Further, in the ink supply system 61 according to the present embodiment, ink circulates including the ink tank 71. Therefore, a part of the ink flowing from the ink tank 71 to the ink flow path 72 returns to the ink tank 71.

In the present embodiment, the ink flow path 72 has a forward flow path 81 and a return flow path 83. The forward flow path 81 is a flow path that supplies a part of the ink in the ink tank 71 to the ink head 41 (specifically, a plurality of nozzles 51 constituting the nozzle row 51a). The configuration of the forward flow path 81 is not particularly limited. In the present embodiment, the forward flow path 81 has a first forward flow path 81a, a second forward flow path 81b, and a third forward flow path 81c.

One end of the first forward flow path 81a is connected to the ink tank 71. Specifically, one end of the first forward flow path 81a is connected to the tank outlet 71b formed on the bottom wall forming the bottom surface of the ink tank 71, and communicates with the inside of the ink tank 71. The other end of the first forward flow path 81a is connected to the liquid feed pump 73. The second forward flow path 81b is arranged closer to the ink head 41 than the first forward flow path 81a, in other words, is arranged downstream from the first forward flow path 81a. The ink in the first forward flow path 81a flows into the second forward flow path 81b. One end of the second forward flow path 81b is connected to the liquid feed pump 73. The other end of the second forward flow path 81b is connected to the third forward flow path 81c and the return flow path 83.

The third forward flow path 81c is arranged closer to the ink head 41 than the second forward flow path 81b, and is arranged downstream from the second forward flow path 81b. A part of the ink in the second forward flow path 81b flows to the third forward flow path 81c. One end of the third forward flow path 81c is connected to the other end of the second forward flow path 81b and the return flow path 83. The other end of the third forward flow path 81c is connected to the damper 75.

The return flow path 83 is a flow path for returning a part of the ink flowing out from the ink tank 71 to the ink tank 71. The return flow path 83 connects the intermediate portion of the forward flow path 81 with the ink tank 71. The configuration of the return flow path 83 is not particularly limited. In the present embodiment, the return flow path 83 has a first return flow path 83a and a second return flow path 83b.

A part of the ink in the second forward flow path 81b flows through the first return flow path 83a. One end of the first return flow path 83a is connected to the other end of the second forward flow path 81b and one end of the third forward flow path 81c. The first return flow path 83a, the second forward flow path 81b, and the third forward flow path 81 may be connected to each other via a so-called three-way valve (not shown). The other end of the first return flow path 83a is connected to the relief valve 74.

The second return flow path 83b is arranged closer to the ink tank 71 than the first return flow path 83a. The ink in the first return flow path 83a flows into the second return flow path 83b. One end of the second return flow path 83b is connected to the relief valve 74. The other end of the second return flow path 83b is connected to the ink tank 71. Specifically, the other end of the second return flow path 83b is connected to the tank inflow port 71a formed on the upper wall forming the upper surface of the ink tank 71, and communicates with the inside of the ink tank 71. Therefore, the ink in the first return flow path 83a is flowed into the ink tank 71 through the second return flow path 83b.

The material of the ink flow path 72, that is, the material of the forward flow path 81 and the return flow path 83 is not particularly limited. The forward flow path 81 and the return flow path 83 are formed of, for example, a flexible tube.

The liquid feed pump 73 is provided in the forward flow path 81. Here, the liquid feed pump 73 is arranged between the first forward flow path 81a and the second forward flow path 81b. The liquid feed pump 73 is connected to the other end of the first forward flow path 81a and one end of the second forward flow path 81b. By driving the liquid feed pump 73, a part of the ink stored in the ink tank 71 and flowing out from the ink tank 71 is supplied to the nozzles 51 constituting the nozzle row 51a of the ink head 41. .. Further, when the liquid feed pump 73 is driven, another part of the ink flowing out from the ink tank 71 flows into the return flow path 83. The type of the liquid feed pump 73 is not particularly limited. The liquid feed pump 73 is, for example, a diaphragm pump, a tube pump, or the like. Further, the liquid feed pump 73 is electronically controlled.

The relief valve 74 manages the pressure of the ink head 41. In other words, the relief valve 74 manages the pressure in the ink flow path 72. By opening and closing the relief valve 74, the pressure applied to the ink head 41 and the ink flow path 72 can be adjusted. The relief valve 74 is provided in the return flow path 83 so that the return flow path 83 can be opened and closed. Here, the relief valve 74 is arranged between the first return flow path 83a and the second return flow path 83b. The relief valve 74 is connected to the other end of the first return flow path 83a and one end of the second return flow path 83b.

The specific configuration of the relief valve 74 is not particularly limited. FIG. 5 is a perspective view of the relief valve 74. FIG. 6 is a cross-sectional view of the relief valve 74 in the VI-VI line of FIG. 7 to 9 are cross-sectional views of the relief valve 74, which is a view corresponding to FIG. 6 and 7 show the relief valve 74 in the first state S1. In FIG. 6, the relief valve 74 is open, and in FIG. 7, the relief valve 74 is closed. 8 and 9 show the relief valve 74 in the second state S2. In FIG. 8, the relief valve 74 is open, and in FIG. 9, the relief valve 74 is closed.

As shown in FIGS. 5 and 6, the relief valve 74 includes a valve body 151, a first valve ink chamber 152aa, a second valve ink chamber 152b, a valve valve body 153, a valve rod 154, and a solenoid 155. It has.

As shown in FIG. 6, the bulb main body 151 is provided with a first bulb ink chamber 152aa and a second bulb ink chamber 152b. In the present embodiment, a downwardly recessed space is formed in the upper part of the valve body 151. A cover 156 is provided on the upper part of the valve body 151 so as to cover the recessed space below the valve body 151. Therefore, a space 152a is formed between the valve body 151 and the cover 156. In the present embodiment, the space 152a includes a first valve ink chamber 152aa, a first operating chamber 152ab located above the first bulb ink chamber 152aa, and a second operating chamber 152ac located above the first operating chamber 152ab. It is divided into. Here, the first valve ink chamber 152aa and the first operating chamber 152ab are separated by the valve valve body 153. The first bulb ink chamber 152aa is an example of the bulb ink chamber.

In the present embodiment, the first bulb ink chamber 152aa is formed with a bulb inlet 157a and a bulb outlet 158a. The bulb inlet 157a is formed in the lower part of the side surface of the first bulb ink chamber 152aa. A horizontally extending valve inflow path 157 is connected to the valve inflow port 157a. The valve inflow path 157 is formed in the valve body 151. The valve inflow path 157 is a path through which ink flows into the relief valve 74. Here, one end of the valve inflow path 157 is connected to the other end of the first return flow path 83a (see FIG. 4) of the return flow path 83 of the ink flow path 72. The other end of the valve inflow path 157 is connected to the valve inflow port 157a.

The second bulb ink chamber 152b is provided below the first bulb ink chamber 152aa and below the bulb body 151. In the present embodiment, the second bulb ink chamber 152b is a space that is shorter in the vertical direction and longer in the lateral direction than the first bulb ink chamber 152aa. In the present embodiment, the portion forming the bottom surface of the second bulb ink chamber 152b is formed by the cover 156a. That is, the second bulb ink chamber 152b is a space surrounded by the bulb main body 151 and the cover 156a. The cover 156a is removable from the valve body 151.

In the present embodiment, the first bulb ink chamber 152aa and the second bulb ink chamber 152b communicate with each other. Specifically, a bulb outlet 158a is formed on the surface (here, the bottom surface) of the first bulb ink chamber 152aa on the side of the second bulb ink chamber 152b. A communication inlet 158b is formed on the surface (here, the upper surface) of the second bulb ink chamber 152b on the side of the first bulb ink chamber 152aa. The valve outlet 158a and the communication inlet 158b are connected to the communication passage 158. In this way, the first bulb ink chamber 152aa and the second bulb ink chamber 152b communicate with each other through the communication passage 158.

Further, a communication outlet 159a is formed in the second bulb ink chamber 152b. The communication outlet 159a is formed on the upper part of the side surface of the second bulb ink chamber 152b. A horizontally extending valve outflow passage 159 is formed at the communication outlet 159a. The valve outflow passage 159 is arranged below the valve inflow passage 157. The valve outflow path 159 is a path through which ink flows out from the relief valve 74. The valve outflow path 159 is formed in the valve body 151. Here, one end of the valve outflow path 159 is connected to the communication outlet 159a. The other end of the valve outflow path 159 is connected to one end of the second return flow path 83b (see FIG. 4) of the return flow path 83. In the present embodiment, the bulb outflow passage 159 is indirectly connected to the bulb outlet 158a via the second bulb ink chamber 152b and the communication passage 158.

The valve valve body 153 can open and close the valve outlet 158a by elastically deforming. However, the valve valve body 153 may be capable of opening and closing the valve inflow port 157a. The valve valve body 153 is arranged in the first valve ink chamber 152aa, and opens and closes the communication passage 158 by opening and closing the valve outlet 158a. In the present embodiment, the valve valve body 153 is supported in a state where the outer peripheral end of the valve valve body 153 is sandwiched between the valve body 151 and the cover 156. The material of the valve body 153 is not particularly limited. Here, the valve valve body 153 is made of rubber.

The valve rod 154 comes into contact with the valve valve body 153 and moves in the vertical direction to elastically deform the valve valve body 153. In the present embodiment, the valve rod 154 extends vertically, and a part of the valve rod 154 is arranged from the first operating chamber 152ab to the second operating chamber 152ac. The valve rod 154 penetrates the cover 156, and the upper portion of the valve rod 154 extends upward from the cover 156. The valve rod 154 is configured to be movable up and down with respect to the first operating chamber 152ab and the second operating chamber 152ac. Further, the valve rod 154 comes into contact with the valve valve body 153 as described above. The valve rod 154 pushes the valve valve body 153 downward, so that the valve valve body 153 closes the valve outlet 158a.

In this embodiment, the valve rod 154 has a guide 154a extending along the side surface of the second working chamber 152ac. The guide 154a allows the valve rod 154 to move up and down along the side surface of the second working chamber 152ac. In the present embodiment, the first operating chamber 152ab and the second operating chamber 152ac are separated by the guide 154a. Although not shown, a gap is formed between the guide 154a and the cover 156. The first operating chamber 152ab and the second operating chamber 152ac communicate with each other by the gap.

In the present embodiment, the first spring 161 is arranged in the second operating chamber 152ac. The first spring 161 is arranged so as to surround the valve rod 154. The first spring 161 applies an elastic force to the valve body 153 in the direction toward the valve outlet 158a (here, downward). In other words, the first spring 161 applies an elastic force in the direction (here, downward) of pressing the valve rod 154 against the valve valve body 153.

The solenoid 155 adjusts the pressure of the ink flow path 72 when the valve valve body 153 opens the valve outlet 158a by changing the load applied from the valve rod 154 on the valve valve body 153. The solenoid 155 is arranged above the valve body 151 and the valve rod 154.

In the present embodiment, the solenoid 155 has a solenoid main body 165 and a shaft core 166. The solenoid body 165 has a space that opens downward inside. The shaft core 166 is inserted through the solenoid main body 165 and can move up and down with respect to the solenoid main body 165. The shaft core 166 is in contact with the valve rod 154, and the shaft core 166 moves downward to come into contact with the valve rod 154. A flange 167 extending laterally is provided at the lower part of the shaft core 166.

In the present embodiment, the solenoid 155 is provided with a second spring 162. The second spring 162 is arranged so as to surround the shaft core 166. The second spring 162 is interposed between the solenoid main body 165 and the flange 167 of the shaft core 166. The second spring 162 applies a downward elastic force to the shaft core 166. The second spring 162 applies an elastic force to the shaft core 166 in a direction away from the solenoid main body 165.

In the present embodiment, the solenoid 155 is a so-called normally closed type solenoid. By turning the solenoid 155 ON or OFF, the state of the relief valve 74 can be changed to the first state S1 (see FIG. 6) or the second state S2 (see FIG. 8). Here, by turning the solenoid 155 ON or OFF, the vertical position of the shaft core 166 with respect to the solenoid main body 165 and the movement range of the shaft core 166 are changed. Here, turning on the solenoid 155 means a state in which the solenoid 155 is energized, and turning off the solenoid 155 means a state in which the solenoid 155 is not energized.

Here, as shown in FIGS. 6 and 7, when the solenoid 155 is ON, the relief valve 74 is in the first state S1. When the solenoid 155 is turned on, that is, the relief valve 74 is in the first state S1, the position of the shaft core 166 with respect to the solenoid body 165 is fixed. When the solenoid 155 is ON, the second spring 162 is in a contracted state, but the shaft core 166 does not move up and down due to the elastic force of the second spring 162.

As shown in FIGS. 8 and 9, when the solenoid 155 is OFF, the relief valve 74 is in the second state S2. When the solenoid 155 is turned off, that is, the relief valve 74 is in the second state S2, the shaft core 166 can move up and down with respect to the solenoid body 165. When the solenoid 155 is OFF and no upward force is applied to the shaft core 166, the shaft core 166 is in a state of being pushed downward by the second spring 162 as shown in FIG. At this time, the shaft core 166 is located below the position of the shaft core 166 (see FIG. 7) when the solenoid 155 is ON.

In the relief valve 74 according to the present embodiment, the pressure at which the valve valve body 153 opens the valve outlet 158a can be changed by turning the solenoid 155 ON or OFF. Here, as shown in FIGS. 6 and 7, when the relief valve 74 is in the first state S1 and the solenoid 155 is ON, the pressure in the valve inflow path 157 is equal to or higher than the first pressure P1 and the valve valve body 153 is a valve. The outlet 158a is opened. On the other hand, as shown in FIGS. 8 and 9, when the relief valve 74 is in the second state S2 and the solenoid 155 is OFF, the pressure in the valve inflow path 157 is the second pressure P2 or more, and the valve valve body 153 is in the valve flow. The exit 158a is opened. Here, the second pressure P2 is higher than the first pressure P1.

The specific numerical values of the first pressure P1 and the second pressure P2 are not particularly limited. The first pressure P1 is 20 kPa to 60 kPa, preferably 30 kPa to 50 kPa, for example, 40 kPa. The second pressure P2 is 120 kPa to 180 kPa, preferably 130 kPa to 170 kPa, for example 150 kPa.

As shown in FIG. 7, when the solenoid 155 is ON in the first state S1, the position of the shaft core 166 of the solenoid 155 is fixed, and the shaft core 166 and the valve rod 154 are separated from each other. .. When the solenoid 155 is ON, only the valve rod 154 can move up and down. Therefore, when the solenoid 155 is ON, the valve rod 154 presses the valve valve body 153 against the valve outlet 158a by the elastic force of the first spring 161 without being affected by the second spring 162, and the valve valve body 153 is connected. The passage 158 is closed. In such a state, when ink flows through the valve inflow path 157 and the pressure becomes the first pressure P1 or higher, the valve valve body 153 resists the elastic force of the first spring 161 as shown in FIG. It moves upward and the valve outlet 158a is opened.

As shown in FIG. 9, when the solenoid 155 is OFF in the second state S2, the position of the shaft core 166 of the solenoid 155 is not fixed, and the shaft core 166 can move up and down. At this time, the shaft core 166 and the valve rod 154 are in contact with each other, and the shaft core 166 and the valve rod 154 can be integrally moved up and down. Therefore, when the solenoid 155 is OFF, the valve rod 154 presses the valve valve body 153 against the valve outlet 158a with the total elastic force of both the first spring 161 and the second spring 162, and the valve valve body 153 communicates with the valve body 153. Close 158. As described above, in order for the valve valve body 153 to open the communication passage 158 when the solenoid 155 is OFF, a pressure resisting the total elastic force of the first spring 161 and the second spring 162 is required. In the present embodiment, when the solenoid 155 is OFF, ink flows through the valve inflow path 157, and when the pressure becomes the second pressure P2 or higher, which is higher than the first pressure P1, the first spring, as shown in FIG. The valve valve body 153 moves upward so as to resist the total elastic force of 161 and the second spring 162, and the valve outlet 158a is opened.

In the relief valve 74 according to the present embodiment, even if the solenoid 155 is ON in the first state S1 and the pressure in the valve inflow path 157 is less than the first pressure P1, the valve valve body 153 has a valve outlet 158a. Is configured to be open. FIG. 10 is a view corresponding to FIG. 6, which shows a state in which the button 168 is moved upward. Here, as shown in FIG. 10, the relief valve 74 includes a button 168. The button 168 can come into contact with the valve body 153 from below, and can push up the valve body 153.

In this embodiment, the button 168 has a shaft portion 168a extending from the second bulb ink chamber 152b toward the communication passage 158. The upper end of the shaft portion 168a can project from the communication passage 158 to the first bulb ink chamber 152aa. A gap is formed between the button 168 (specifically, the shaft portion 168a) and the communication passage 158. Through the gap, ink flows in the communication passage 158 from the valve outlet 158a toward the communication inlet 158b. The gap may be omitted. In that case, the shaft portion 168a may be provided with a notch extending in the axial direction of the shaft portion 168a. Ink flows through the passage 158 through the notch.

In this embodiment, the button 168 can be manually moved up and down. For example, the user may push up the button 168 with the cover 156a attached to the valve body 151 removed. When the button 168 moves upward and the button 168 pushes up the valve valve body 153, the valve valve body 153 moves upward and the valve outlet 158a opens. In this way, the valve outlet 158a can be opened even if the pressure in the valve inflow path 157 is less than the first pressure P1. The cover 156a may be formed of an elastic member such as rubber. In this case, with the cover 156a attached to the valve body 151, the user may push the cover 156a upward to move the button 168 upward. Further, the button 168 may be configured to be movable in the vertical direction by electronic control.

Here, the fact that the relief valve 74 is open means that the valve valve body 153 is in a state where the valve outlet 158a is open. When the relief valve 74 is closed, it means that the valve valve body 153 is in a state where the valve outlet 158a is closed.

The relief valve 74 has been described above. Next, the damper 75 shown in FIG. 4 will be described. The damper 75 keeps the pressure applied to the nozzle surface 45 of the ink head 41 constant and alleviates the pressure fluctuation of the ink to stabilize the ink ejection operation of the ink head 41. The damper 75 is connected to the forward flow path 81. Specifically, the damper 75 is connected to the other end of the third forward flow path 81c. Further, the damper 75 communicates with the nozzles 51 forming the nozzle row 51a of the ink head 41. Here, the damper 75 is provided above the ink head 41.

The configuration of the damper 75 is not particularly limited. FIG. 11 is a perspective view of the damper 75. FIG. 12 is a front view of the damper 75. FIG. 13 is a cross-sectional view of the damper 75 along line XIII-XIII of FIG. 14 and 15 are cross-sectional views of the damper 75, which is a view corresponding to FIG.

In the present embodiment, as shown in FIG. 12, the damper 75 has a damper main body 170, a negative pressure release valve mechanism 171 and a pressure release valve mechanism 181. Note that FIG. 13 shows a state in which the negative pressure release valve mechanism 171 is closed and the pressure release valve mechanism 181 is open. FIG. 14 shows a state in which the negative pressure release valve mechanism 171 is opened and the pressure release valve mechanism 181 is closed. FIG. 15 shows a state in which both the negative pressure release valve mechanism 171 and the pressure release valve mechanism 181 are closed.

As shown in FIG. 11, the damper main body 170 has, for example, a rectangular parallelepiped shape, but the shape of the damper main body 170 is not particularly limited. The damper body 170 is an example of the body of the present invention. As shown in FIG. 12, the damper main body 170 is provided with a negative pressure release valve mechanism 171 and a pressure release valve mechanism 181. As described above, in the present embodiment, the negative pressure release valve mechanism 171 and the pressure release valve mechanism 181 are provided in the same damper main body 170, that is, one damper main body 170, but are provided in different damper main bodies. May be good. Here, for example, when the negative pressure release valve mechanism 171 is provided in the first damper main body and the pressure release valve mechanism 181 is provided in the second damper main body, the first damper main body and the second damper main body are separated from each other. You may be doing it.

The negative pressure release valve mechanism 171 and the pressure release valve mechanism 181 are arranged side by side in the vertical direction. Here, the negative pressure release valve mechanism 171 is arranged above the pressure release valve mechanism 181. However, the negative pressure release valve mechanism 171 may be arranged below the pressure release valve mechanism 181. Further, the negative pressure release valve mechanism 171 and the pressure release valve mechanism 181 may be arranged horizontally side by side.

As shown in FIG. 14, the negative pressure release valve mechanism 171 is a mechanism that releases the ink head 41 (see FIG. 4) by reducing the pressure. In the present embodiment, the negative pressure release valve mechanism 171 opens and closes according to the ejection operation of the ink head 41. For example, the ink head 41 is depressurized by ejecting ink from a plurality of nozzles 51 of the ink head 41. As a result, the negative pressure release valve mechanism 171 is opened, and ink is supplied from the ink tank 71 (see FIG. 4) to the ink head 41 through the negative pressure release valve mechanism 171.

The configuration of the negative pressure release valve mechanism 171 is not particularly limited. In the present embodiment, as shown in FIG. 13, the negative pressure release valve mechanism 171 includes a first inflow path 172 (see FIG. 12), a first negative pressure release ink chamber 173, and a second negative pressure release ink chamber 174. It has an air opening chamber 174b, a valve membrane 175, a first valve body 176, a first valve seat 176a, and a first outflow passage 177 (see FIG. 12).

As shown in FIG. 12, the first inflow path 172 is provided in the damper main body 170. In the present embodiment, the damper main body 170 is formed with a damper inflow port 170a. The first inflow path 172 extends from the damper inflow port 170a toward the first negative pressure release ink chamber 173. Here, one end of the first inflow path 172 is connected to the other end of the third forward flow path 81c (see FIG. 4) via the damper inflow port 170a. The other end of the first inflow path 172 is connected to the first negative pressure release ink chamber 173.

As shown in FIG. 13, the first negative pressure release ink chamber 173 and the second negative pressure release ink chamber 174 are provided in the damper main body 170. Ink is temporarily stored in the first negative pressure release ink chamber 173 and the second negative pressure release ink chamber 174. A first inflow port 173a is formed in the first negative pressure opening ink chamber 173. As shown in FIG. 12, the other end of the first inflow path 172 is connected to the first inflow port 173a.

As shown in FIG. 13, the second negative pressure release ink chamber 174 is formed in the damper main body 170. The second negative pressure release ink chamber 174 is arranged side by side with the first negative pressure release ink chamber 173. A communication port 174a is formed in the second negative pressure opening ink chamber 174. The communication port 174a is formed on the surface of the second negative pressure opening ink chamber 174 on the side of the first negative pressure opening ink chamber 173. The second negative pressure release ink chamber 174 communicates with the first negative pressure release ink chamber 173 via the communication port 174a. However, the communication port 174a may be formed on the surface of the first negative pressure opening ink chamber 173. The communication port 174a is indirectly connected to the first inflow path 172 (see FIG. 12) via the first negative pressure opening ink chamber 173. Further, in the present embodiment, as shown in FIG. 12, a first outlet 174c is formed in the second negative pressure opening ink chamber 174.

The atmosphere opening chamber 174b is arranged side by side with the second negative pressure opening ink chamber 174. Here, the atmosphere opening chamber 174b is arranged on the side opposite to the first negative pressure opening ink chamber 173 with respect to the second negative pressure opening ink chamber 174. An atmosphere port 174d is formed in the atmosphere opening chamber 174b. The atmosphere port 174d communicates with the atmosphere, and the atmosphere opening chamber 174b is opened to the atmosphere through the atmosphere port 174d.

In the present embodiment, as shown in FIG. 13, the second negative pressure opening ink chamber 174 and the atmosphere opening chamber 174b are partitioned from each other by a valve membrane 175. The second negative pressure release ink chamber 174 is a space surrounded by the damper main body 170 and the valve membrane 175. The valve membrane 175 is configured to be elastically deformable. The valve membrane 175 is elastic on the outside or inside of the second negative pressure opening ink chamber 174, depending on the amount of ink in the second negative pressure opening ink chamber 174, in other words, based on the pressure of the second negative pressure opening ink chamber 174. change.

The valve membrane 175 indirectly contacts the first valve body 176 in the second negative pressure release ink chamber 174, and exerts a force on the first valve body 176 in the direction in which the first valve body 176 separates from the communication port 174a. It is configured to do. In the present embodiment, the valve membrane 175 is in contact with the first valve body 176 via the rod 178. However, the valve membrane 175 may be in direct contact with the first valve body 176. As described above, the "contact" includes both the case where the valve membrane 175 is in direct contact with the first valve body 176 and the case where the valve membrane 175 is indirectly in contact with the first valve body 176. ..

The material of the valve membrane 175 is not particularly limited. In this embodiment, the valve membrane 175 is made of rubber.

In the present embodiment, the first cover 170b is provided on the side of the valve membrane 175 opposite to the second negative pressure opening ink chamber 174. The material forming the first cover 170b is not particularly limited, but it may be, for example, a material having a light-shielding property. For example, the first cover 170b is made of aluminum.

The air opening chamber 174b is a space surrounded by the first cover 170b and the valve membrane 175. The atmosphere port 174d of the air opening chamber 174b is formed in the first cover 170b. The outer peripheral end of the valve membrane 175 is supported in a state of being sandwiched between the damper main body 170 and the first cover 170b.

The first valve body 176 opens and closes the communication port 174a. Here, the first valve body 176 can open and close the communication port 174a as the valve membrane 175 is elastically deformed. In the present embodiment, the first valve body 176 is arranged in the first negative pressure opening ink chamber 173, and opens and closes the communication port 174a from the first negative pressure opening ink chamber 173 side.

In the present embodiment, the first valve body 176 comes into contact with the first valve seat 176a when the communication port 174a is closed. The first valve seat 176a is formed on the surface of the first negative pressure opening ink chamber 173 on the side of the second negative pressure opening ink chamber 174. The first valve seat 176a extends in the vertical direction. Although not shown, a hole is formed in the first valve seat 176a, and the hole communicates with the communication port 174a.

In the present embodiment, the first valve body 176 is provided with a rod 178. The rod 178 is inserted into the communication port 174a and extends from the first valve body 176 toward the second negative pressure opening ink chamber 174. A gap is formed between the rod 178 and the communication port 174a. The tip of the rod 178 is in contact with the valve membrane 175. The rod 178 is configured to move in response to elastic deformation of the valve membrane 175. When the rod 178 moves in response to the elastic deformation of the valve membrane 175, the tip of the rod 178 does not have to be in contact with the valve membrane 175.

Further, in the present embodiment, the negative pressure release valve mechanism 171 has a first negative pressure release spring 179a and a second negative pressure release spring 179b. The first negative pressure release spring 179a applies an elastic force to the first valve body 176 so that the first valve body 176 closes the communication port 174a. In the present embodiment, the first negative pressure release spring 179a is arranged in the first negative pressure release ink chamber 173 in a contracted state. The second negative pressure release spring 179b applies an elastic force to the valve membrane 175 toward the outside of the second negative pressure release ink chamber 174 (to the left in FIG. 13). The second negative pressure release spring 179b is arranged in the second negative pressure release ink chamber 174 in a contracted state.

Here, as shown in FIGS. 13 and 14, the rod is elastically deformed toward the outside (left direction in FIG. 13) or the inside (right direction in FIG. 13) of the second negative pressure release ink chamber 174 in the valve membrane 175. The 178 moves in the axial direction of the rod 178. As the rod 178 moves, the first valve body 176 opens and closes the communication port 174a.

As shown in FIG. 12, the first outflow passage 177 is provided in the damper main body 170. In the present embodiment, the damper main body 170 is formed with a damper outlet 170c. The first outflow passage 177 extends from the damper outlet 170c toward the second negative pressure release ink chamber 174. Here, one end of the first outflow path 177 is connected to the first outflow port 174c formed in the second negative pressure release ink chamber 174. The other end of the first outflow path 177 is connected to the ink head 41 (see FIG. 4) via the damper outlet 170c and communicates with the nozzle 51 formed on the nozzle surface 45 of the ink head 41.

Here, the fact that the negative pressure release valve mechanism 171 is open means that the first valve body 176 is in a state where the communication port 174a is open. The fact that the negative pressure release valve mechanism 171 is closed means that the first valve body 176 closes the communication port 174a.

The pressure release valve mechanism 181 opens when the ink flow path 72 (see FIG. 4) is pressurized. The pressure release valve mechanism 181 is used when performing pressure cleaning, which will be described later.

The configuration of the pressure release valve mechanism 181 is not particularly limited. In the present embodiment, as shown in FIG. 13, the pressure release valve mechanism 181 includes a second inflow passage 182, a pressure release ink chamber 183, a second valve body 185, a second valve seat 185a, and a second. It has two outflow passages 186 (see FIG. 12).

As shown in FIG. 12, the second inflow path 182 is provided in the damper main body 170. The second inflow path 182 extends from the damper inflow port 170a formed in the damper main body 170 toward the pressurized release ink chamber 183. In the present embodiment, a part of the second inflow path 182 (specifically, the end on the damper inflow port 170a side) overlaps with a part of the first inflow path 172 (specifically, the end on the damper inflow port 170a side). ing. One end of the second inflow path 182 is connected to the other end of the third forward flow path 81c (see FIG. 4) via the damper inflow port 170a. As shown in FIG. 13, the other end of the second inflow path 182 is connected to the pressurized release ink chamber 183.

Ink is temporarily stored in the pressurized open ink chamber 183. The pressurized open ink chamber 183 is provided in the damper main body 170. In the present embodiment, a part of the outer surface of the damper main body 170 is recessed inside the damper main body 170. The recessed portion inside the damper body 170 is covered by the second cover 170d. The material forming the second cover 170d is not particularly limited, but it may be, for example, a material having a light-shielding property. For example, the second cover 170d is made of aluminum. Here, the space surrounded by the damper main body 170 and the second cover 170d is the pressurized open ink chamber 183.

A second inflow port 183a is formed in the pressurized open ink chamber 183. As shown in FIG. 12, the other end of the second inflow path 182 is connected to the second inflow port 183a. Further, a second outlet 183b is formed in the pressurized open ink chamber 183.

As shown in FIGS. 13 and 14, the second valve body 185 opens and closes the second inflow port 183a according to the pressure in the second inflow path 182. In the present embodiment, the second valve body 185 is arranged in the pressure-opening ink chamber 183, and opens and closes the second inflow port 183a from the pressure-opening ink chamber 183 side. Here, the end of the second valve body 185 is supported in a state of being sandwiched between the damper main body 170 and the second cover 170d.

In this embodiment, the second valve body 185 comes into contact with the second valve seat 185a when the second inflow port 183a is closed. The second valve seat 185a is formed on the surface of the pressurized open ink chamber 183 on the second inflow path 182 side. The second valve seat 185a extends in the vertical direction. In the present embodiment, the second valve seat 185a is formed with a second inflow port 183a.

In the present embodiment, the pressure release valve mechanism 181 has a pressure release spring 189. The pressure release spring 189 applies an elastic force to the second valve body 185 so that the second valve body 185 closes the second inflow port 183a. In the present embodiment, the pressure release spring 189 is arranged in the pressure release ink chamber 183 in a contracted state.

As shown in FIG. 12, the second outflow passage 186 is provided in the damper main body 170. The second outflow passage 186 extends from the damper outlet 170c formed in the damper main body 170 toward the pressurized release ink chamber 183. In the present embodiment, a part of the second outflow passage 186 (specifically, the end on the damper outlet 170c side) overlaps with a part of the first outflow passage 177 (specifically, the end on the damper outlet 170c side). ing. One end of the second outflow path 186 is connected to the second outflow port 183b of the pressurized open ink chamber 183. The other end of the second outflow path 186 is connected to the ink head 41 (see FIG. 4) via the damper outlet 170c.

In the present embodiment, as shown in FIG. 13, the central shaft L1 of the first valve seat 176a of the negative pressure release valve mechanism 171 and the central shaft L2 of the second valve seat 185a of the pressure release valve mechanism 181 are substantially abbreviated. It is parallel and almost horizontal. In addition to strict parallelism, substantially parallel includes those in which the central axis L1 and the central axis L2 are slightly tilted. Similarly, the substantially horizontal includes not only the exact horizontal but also the one slightly inclined with respect to the horizontal plane. Here, the central axes L1 and L2 both extend in the left-right direction of FIG.

Both the negative pressure release valve mechanism 171 and the pressure release valve mechanism 181 are configured so that ink flows from the right to the left in FIG. In the negative pressure release valve mechanism 171, the first inflow port 173a is arranged on one side (right side in FIG. 13) of the first valve seat 176a, and the first flow is on the other side (left side in FIG. 13) of the first valve seat 176a. The exit 174c is arranged. In the pressure release valve mechanism 181, the second inflow port 183a is arranged on one side of the second valve seat 185a, and the second outflow port 183b is arranged on the other side of the second valve seat 185a.

Here, the opening of the pressure release valve mechanism 181 means a state in which the second valve body 185 opens the second inflow port 183a. The fact that the pressure release valve mechanism 181 is closed means that the second valve body 185 is in a state where the second inflow port 183a is closed.

In the damper 75 according to the present embodiment, the negative pressure release valve mechanism 171 opens when the ink head 41 depressurizes (see FIG. 14), and the pressure release valve mechanism 181 opens when the ink flow path 72 pressurizes. Opens (see FIG. 13). Whether or not the negative pressure release valve mechanism 171 is opened depends on the closing force F1 which is the force acting in the direction in which the first valve body 176 closes the communication port (to the left in FIG. 13) and the first valve body. It is determined by the relationship with the opening force F2, which is the force acting on the 176 in the direction of opening the communication port (to the right in FIG. 13). In FIGS. 13 to 15, the lengths of the arrows indicating the closing force F1 and the opening force F2 indicate the relationship between the magnitudes of the forces.

Here, the closing force F1 is determined by the sum of the pressure in the first negative pressure opening ink chamber 173 and the elastic force applied to the first valve body 176 by the first negative pressure opening spring 179a. The opening force F2 is determined by the sum of the pressure in the second negative pressure opening ink chamber 174 and the elastic force applied to the valve membrane 175 by the second negative pressure opening spring 179b. Here, as shown in FIG. 13, when the closing force F1 is equal to or greater than the opening force F2, that is, when F1 ≧ F2, the negative pressure release valve mechanism 171 closes. On the other hand, as shown in FIG. 14, when the closing force F1 is less than the opening force F2, that is, F1 <F2, the negative pressure release valve mechanism 171 opens.

In the present embodiment, for example, when the pressure of the first negative pressure open ink chamber 173 is less than the first pressure P1, ink is not ejected from the ink head 41. Therefore, at this time, the pressure of the second negative pressure opening ink chamber 174 is equal to or higher than the predetermined opening pressure P10. The opening pressure P10 is a negative pressure, for example, −0.1 kPa. When the pressure of the first negative pressure opening ink chamber 173 is less than the first pressure P1, the pressure of the second negative pressure opening ink chamber 174 becomes near the atmospheric pressure. At this time, as shown in FIG. 13, since the closing force F1 is equal to or greater than the opening force F2, the negative pressure release valve mechanism 171 is closed.

On the other hand, when the ink flows into the first negative pressure open ink chamber 173 and the pressure in the first negative pressure open ink chamber 173 becomes equal to or higher than the first pressure P1, the ink is ejected from the ink head 41. As a result, the pressure in the second negative pressure open ink chamber 174 is reduced together with the pressure in the ink head 41, and becomes less than the above open pressure P10 (for example, about −0.2 kPa to −0.8 kPa). As a result, as shown in FIG. 14, the closing force F1 becomes less than the opening force F2, so that the negative pressure release valve mechanism 171 is opened. As a result, the ink in the first negative pressure opening ink chamber 173 flows into the second negative pressure opening ink chamber 174.

In the present embodiment, at the timing when the negative pressure release valve mechanism 171 is opened, ink is ejected from the ink head 41, the pressure in the second negative pressure release ink chamber 174 is reduced to less than the opening pressure P10, and the pressure is reduced. The elastic force of the first negative pressure release spring 179a and the elastic force of the second negative pressure release spring 179b are set so that the pressure of the 1 negative pressure release ink chamber 173 becomes the timing equal to or higher than the first pressure P1. There is.

In the present embodiment, for example, the liquid feed pump 73 (see FIG. 4) is driven to increase the amount of ink flowing through the ink flow path 72 per unit time, and the pressure of the ink flow path 72 becomes equal to or higher than the third pressure P3. Then, in the pressure release valve mechanism 181, the pressure of the second inflow passage 182 becomes equal to or higher than the third pressure P3. As a result, as shown in FIG. 13, the second valve body 185 opens the second inflow port 183a. The second valve body 185 closes the second inflow port 183a when the pressure in the second inflow path 182 is lower than the third pressure P3, and when the pressure in the second inflow path 182 is equal to or higher than the third pressure P3, the second valve body 185 is second. 2 It is configured to open the inflow port 183a.

In the present embodiment, the third pressure P3 is higher than the first pressure P1 and lower than the second pressure P2. The third pressure P3 is 80 kPa to 120 kPa, preferably 90 kPa to 110 kPa, for example 100 kPa.

When the pressure in the ink flow path 72 is equal to or higher than the third pressure P3, the ink in the ink flow path 72 flows to the ink head 41 through the pressure release valve mechanism 181. When the pressure of the ink flow path 72 becomes the third pressure P3 or more, the pressure of the first negative pressure opening ink chamber 173 in the negative pressure release valve mechanism 171 becomes the third pressure P3 or more. As shown, the first valve body 176 remains in a state where the communication port 174a is closed. Therefore, even when the pressure of the ink flow path 72 becomes the third pressure P3 or higher, the negative pressure release valve mechanism 171 is not opened.

The configuration of the ink supply system 61 has been described above. Next, the cap unit 110 and the wiper mechanism 140 will be described. FIG. 16 is a front view of the cap unit 110. FIG. 16 is a diagram showing a state in which the caps 111 to 114 are not attached to the nozzle surface 45, respectively.

In this embodiment, as shown in FIG. 16, the cap unit 110 includes caps 111 to 114, a capping mechanism 120, and suction pumps 131 to 134.

The caps 111 to 114 are configured to be mounted on the nozzle surface 45 of the ink heads 41 to 44, respectively. Here, "mounting" means a state in which the nozzles 51 to 58 are attached to the ink heads 41 to 44 so as to be covered with the caps 111 to 114. In "mounting", the caps 111 to 114 are fitted to the lower portions of the ink heads 41 to 44, respectively, and the end faces of the caps 111 to 114 (here) so that the caps 111 to 114 cover the nozzles 51 to 58. It is assumed that the upper end surface) is in contact with the nozzle surface 45 of the ink heads 41 to 44, respectively.

In this embodiment, the caps 111 to 114 are arranged side by side in the main scanning direction Y. The caps 111 to 114 have a box-like shape with an open top. The type of material forming the caps 111 to 114 is not particularly limited. At least the portions of the caps 111 to 114 that come into contact with the ink heads 41 to 44 are formed of, for example, rubber. Further, an absorber (not shown) such as a sponge is arranged inside the caps 111 to 114. The shape of the upper opening of the caps 111 to 114 corresponds to the shape of the outer peripheral portion of the ink heads 41 to 44.

The capping mechanism 120 is a mechanism for raising and lowering the caps 111 to 114 as shown by the arrows in FIG. The capping mechanism 120 is a mechanism for attaching or separating caps 111 to 114 from the nozzle surfaces 45 of the ink heads 41 to 44, respectively. In the present embodiment, the capping mechanism 120 is configured to raise and lower the caps 111 to 114 at the same time without changing the relative positions of the caps 111 to 114.

The specific configuration of the capping mechanism 120 is not particularly limited. In the present embodiment, the capping mechanism 120 includes a support member 121 and a capping motor 122. The support member 121 is a member that supports the caps 111 to 114. Here, the support member 121 is a plate-shaped member. The capping motor 122 is connected to the support member 121. By driving the capping motor 122, the support member 121 moves up and down. As the support member 121 moves up and down, the caps 111 to 114 move up and down at the same time.

The suction pumps 131 to 134 are connected to caps 111 to 114, respectively. The suction pumps 131 to 134 are members that suck ink, air, and the like in the caps 111 to 114, respectively. The types of suction pumps 131 to 134 are not particularly limited. The suction pumps 131 to 134 are, for example, vacuum pumps. The suction pumps 131 to 134 are connected to the bottom surfaces of the caps 111 to 114 via tubes or the like, respectively. For example, when the suction pumps 131 to 134 are driven with the caps 111 to 114 attached to the nozzle surfaces 45 of the ink heads 41 to 44, ink and the like are sucked out from the nozzles 51 to 58 of the ink heads 41 to 44. Is done. The ink or the like sucked by the suction pumps 131 to 134 is discarded in a waste liquid tank (not shown) via a tube or the like (not shown).

In the present embodiment, the caps 111 to 114 are arranged at the home position (not shown) located at the right end of the guide rail 15 (see FIG. 1). Therefore, the head moving mechanism 30 (see FIG. 1) moves the ink heads 41 to 44 in the main scanning direction Y, so that the relative positions of the ink heads 41 to 44 with respect to the caps 111 to 114 in the main scanning direction Y are changed. can do. By moving the ink heads 41 to 44 in the main scanning direction Y, the ink heads 41 to 44 can be arranged at positions where the nozzle surfaces 45 of the ink heads 41 to 44 overlap with the caps 111 to 114 in a plan view. .. Then, in a plan view, the nozzle surfaces 45 of the ink heads 41 to 44 overlap the caps 111 to 114, respectively, and the caps 111 to 114 are raised to cap the nozzle surfaces 45 of the ink heads 41 to 44, respectively. 111-114 can be attached.

FIG. 17 is a front view of the wiper mechanism 140. The wiper mechanism 140 is arranged in the vicinity of the caps 111 to 114, and is provided below the ink heads 41 to 44 as shown in FIG. The wiper mechanism 140 is a mechanism for wiping the nozzle surface 45 of the ink heads 41 to 44. The configuration of the wiper mechanism 140 is not particularly limited. In the present embodiment, the wiper mechanism 140 includes a wiper 141, a rotary shaft 142, a cleaning liquid tank 143, and a rotary motor 144.

The wiper 141 is a member that wipes the nozzle surface 45 of the ink heads 41 to 44. The wiper 141 is a flat plate-shaped member extending in the front-rear direction and the up-down direction. The length of the wiper 141 in the front-rear direction is longer than the length of the ink heads 41 to 44 in the front-rear direction. The wiper 141 is made of rubber, for example. One end of the wiper 141 is connected to the rotating shaft 142.

The wiper 141 is configured to be rotatable around a rotation shaft 142. The rotation shaft 142 extends in the front-rear direction. When the wiper 141 is arranged in a rotational position such that the end farther from the rotation shaft 142 is facing up, the end is located slightly higher than the nozzle surface 45 of the ink heads 41-44. .. Therefore, when the carriage 17 is driven while the wiper 141 is arranged at such a rotation position, the nozzle surface 45 of the ink heads 41 to 44 can be wiped by the wiper 141. On the other hand, when the wiper 141 is arranged at a rotation position such that the end farther from the rotation shaft 142 is facing down, the wiper 141 is immersed in the cleaning liquid in the cleaning liquid tank 143 installed below the rotation shaft 142. The wiper 141 is rotated by a rotary motor 144.

Next, the control device 200 shown in FIG. 1 will be described. The control device 200 is a device that controls printing and the like. The configuration of the control device 200 is not particularly limited. The control device 200 is, for example, a microcomputer. The hardware configuration of the microcomputer is not particularly limited, but for example, an interface (I / F) for receiving print data or the like from an external device such as a host computer, and a central processing unit (CPU: central) for executing control program instructions. A processing unit), a ROM (read only memory) that stores programs executed by the CPU, a RAM (random access memory) that is used as a working area for deploying programs, and a memory that stores the above programs and various data. It is equipped with a storage device. The control device 200 does not necessarily have to be provided inside the printer 100. For example, it may be a computer installed outside the printer 100 and connected to the printer 100 by wire or wirelessly so as to be able to communicate with the printer 100.

FIG. 18 is a block diagram of the printer 100. As shown in FIG. 18, the control device 200 is communicably connected to the feed motor 23 of the transport mechanism 20 and the carriage motor 33 of the head moving mechanism 30 to control the transport mechanism 20 and the head moving mechanism 30. The control device 200 is communicatively connected to the ink heads 41 to 44, and controls the timing of ink ejected from the nozzles 51 to 58 (see FIG. 2) of the ink heads 41 to 44. Further, the control device 200 is communicably connected to the liquid feed pump 73, and controls the drive of the liquid feed pump 73 to control the amount of ink flowing through the ink flow path 72. The control device 200 is communicably connected to the relief valve 74 and controls the opening and closing of the relief valve 74. Here, the control device 200 is communicably connected to the solenoid 155 and the button 168 of the relief valve 74. The control device 200 changes the vertical position and the moving range of the shaft core 166 by controlling the ON or OFF of the solenoid 155, and changes the state of the relief valve 74 to the first state S1 or the second state S2. do. Further, the control device 200 controls the position of the button 168 in the vertical direction.

In this embodiment, the control device 200 is communicably connected to the capping mechanism 120. The control device 200 controls the attachment / detachment of the caps 111 to 114 with respect to the nozzle surface 45 of the ink heads 41 to 44 by controlling the capping mechanism 120. The control device 200 is communicably connected to the suction pumps 131 to 134 and controls the drive of the suction pumps 131 to 134. Further, the control device 200 is communicably connected to the rotary motor 144 of the wiper mechanism 140, and controls the wiper 141 with respect to the nozzle surface 45 of the ink heads 41 to 44 by controlling the rotary motor 144.

In the present embodiment, the control device 200 includes a storage unit 201, a capping control unit 210, a cleaning suction pump control unit 211, a cleaning liquid feed pump control unit 213, a first cleaning pump control unit 215, and a second cleaning. It includes a pump control unit 216, a cleaning valve control unit 217, and a wiping control unit 219. Further, the control device 200 includes a print pump control unit 221, a print valve control unit 223, a first circulation control unit 225, a second circulation control unit 227, and a maintenance control unit 229. Each part of the control device 200 may be composed of software or hardware. Further, each part of the control device 200 may be performed by a processor or may be incorporated in a circuit. If done by a processor, the number of processors may be one or plural. The specific control of each part of the control device 200 described above will be described later.

The configuration of the printer 100 according to this embodiment has been described above. In the present embodiment, the operation of the printer 100 includes a printing operation, a first cleaning operation, a second cleaning operation, a third cleaning operation, a wiping operation, a circulation operation, and a maintenance operation. Depending on each operation, the operation of each member constituting the ink supply systems 61 to 68 may be different. Each operation will be described below.

The printing operation is an operation of printing by ejecting ink from nozzles 51 to 58 (see FIG. 2) of the ink heads 41 to 44 onto the medium 5 (see FIG. 1) supported by the platen 13. 19 and 20 are schematic views showing the states of the ink supply systems 61 to 68 during the printing operation. FIG. 19 shows when the pressure of the ink flow path 72 is higher than the first pressure P1. FIG. 20 shows the case where the pressure of the ink flow path 72 is equal to or less than the first pressure P1. In FIGS. 19 to 26, the arrows indicate the ink flow. Further, in FIGS. 19 to 26, when the liquid feed pump 73 and the suction pumps 131 to 134 are stopped, “x” is shown, and when they are driven, “x” is not shown. 19 to 26, when the relief valve 74, the negative pressure release valve mechanism 171 and the pressure release valve mechanism 181 are closed, “x” is shown, and when they are open, “x” is shown. do not have.

In the printing operation, as shown in FIGS. 19 and 20, a part of the ink stored in the ink tank 71 is supplied to the ink heads 41 to 44, and the other part of the ink is appropriately circulated. In the present embodiment, the control of the ink supply systems 61 to 68 in the printing operation is performed by the printing pump control unit 221 and the printing bulb control unit 223 shown in FIG.

In the printing operation, the printing pump control unit 221 controls the liquid feeding pump 73 so as to drive the liquid feeding pump 73, as shown in FIG. Then, the print valve control unit 223 controls the relief valve 74 so that the relief valve 74 is in the first state S1 (see FIG. 6). Specifically, the print valve control unit 223 turns on the solenoid 155 of the relief valve 74. Therefore, in the printing operation, as shown in FIG. 6, when the pressure of the ink flow path 72 (in other words, the pressure of the valve inflow path 157) becomes equal to or higher than the first pressure P1, the relief valve 74 opens.

In the printing operation, when ink is ejected from the ink heads 41 to 44, the ink in the second negative pressure release ink chamber 174 of the negative pressure release valve mechanism 171 of the damper 75 is supplied to the ink heads 41 to 44. Therefore, the amount of ink in the second negative pressure opening ink chamber 174 is reduced and the pressure is reduced, so that the valve membrane 175 is elastically deformed inside the second negative pressure opening ink chamber 174 as shown in FIG. When the pressure of the second negative pressure opening ink chamber 174 becomes less than the opening pressure P10 (for example, −0.1 kPa), the closing force F1 with respect to the first valve body 176 becomes less than the opening force F2. At this time, the first valve body 176 pushed by the elastic deformation of the second negative pressure opening ink chamber 174 in the valve membrane 175 opens the communication port 174a. As a result, as shown in FIG. 20, the negative pressure release valve mechanism 171 opens.

As a result, the ink in the ink tank 71 is supplied to the ink heads 41 to 44 through the forward flow path 81. By opening the negative pressure release valve mechanism 171 in this way, the pressure of the ink flow path 72 also becomes the first pressure P1 or less, but the ink is supplied from the ink tank 71 to the ink heads 41 to 44. The pressure of the ink flow path 72 returns to the first pressure P1 or higher. Therefore, the relief valve 74 may be closed at the timing when the ink is supplied to the ink heads 41 to 44.

In the present embodiment, when the pressure of the ink flow path 72 (specifically, the forward flow path 81 and the first return flow path 83a) becomes the first pressure P1 or higher, the relief valve 74 is in the first state S1, so that it is a valve valve. The body 153 opens the valve outlet 158a (see FIG. 6), and the relief valve 74 is in an open state. As shown in FIG. 19, when the pressure of the ink flow path 72 is equal to or higher than the first pressure P1, the negative pressure release valve mechanism 171 is in an open state, and the ink in the first negative pressure release ink chamber 173 is released. It flows to the second negative pressure release ink chamber 174. Therefore, the pressure of the second negative pressure opening ink chamber 174 becomes the opening pressure P10 or more, and as shown in FIG. 13, the closing force F1 with respect to the first valve body 176 becomes the opening force F2 or more, and the negative pressure opening valve mechanism 171 Will be in a closed state. Therefore, in the printing operation, when the pressure of the ink flow path 72 becomes equal to or higher than the first pressure P1, the ink flowing out from the ink tank 71 circulates in the first forward flow path 81a, the second forward flow path 81b, and the return flow path 83. become. As described above, in the printing operation, the supply of ink to the ink heads 41 to 44 and the circulation of the ink including the ink tank 71 are repeated with reference to the first pressure P1.

Next, the first to third cleaning operations will be described. Here, in the cleaning operation, as shown in FIG. 16, caps 111 to 114 are attached to the nozzle surfaces 45 of the ink heads 41 to 44, and the ink in the ink heads 41 to 44 is transferred to the caps 111 to 114. It refers to a cleaning operation for the ink heads 41 to 44 that eject the ink and suppress the ejection clogging of the nozzles 51 to 58. In the present embodiment, in the first to third cleaning operations, the controls for the liquid feed pump 73 and the suction pumps 131 to 134 are different.

FIG. 21 is a schematic view showing the states of the ink supply systems 61 to 68 during the first cleaning operation and the third cleaning operation. As shown in FIG. 21, in the first cleaning operation, the suction pumps 131 to 134 are driven and the liquid feed pump 73 is stopped to clean the ink heads 41 to 44. The control of the ink supply systems 61 to 68 in the first cleaning operation is performed by the capping control unit 210, the cleaning suction pump control unit 211, and the cleaning valve control unit 217 shown in FIG.

In the first cleaning operation, the capping control unit 210 first controls the head moving mechanism 30 so as to move the ink heads 41 to 44 to a home position (not shown). Here, the home position is a position where the ink heads 41 to 44 stand by during printing standby, and is, for example, a position to the right of the guide rail 15 (see FIG. 1). Further, a cap unit 110 is arranged in the vicinity of the home position. With the ink heads 41 to 44 arranged at the home position, the capping control unit 210 controls the capping mechanism 120 (detailedly, the capping motor 122 (see FIG. 16)) to control the nozzle surface of the ink heads 41 to 44. The caps 111 to 114 are attached to 45.

Next, in the first cleaning operation, as shown in FIG. 21, the cleaning suction pump control unit 211 has the suction pumps 131 to 134 with the caps 111 to 114 attached to the nozzle surfaces 45 of the ink heads 41 to 44. And stop the liquid feed pump 73. At this time, the cleaning suction pump control unit 211 can also drive only a part of the suction pumps 131 to 134. Further, in the first cleaning operation, the cleaning valve control unit 217 controls the relief valve 74 so that the relief valve 74 is in the second state S2 (see FIG. 8). Specifically, the cleaning valve control unit 217 turns off the solenoid 155 of the relief valve 74. As a result, the shaft core 166 of the solenoid 155 can move up and down together with the valve rod 154. Therefore, in the first cleaning operation, as shown in FIG. 8, when the pressure of the ink flow path 72 becomes the second pressure P2 or more, the relief valve 74 is opened.

In the first cleaning operation, since the liquid feed pump 73 is stopped, the ink in the ink tank 71 is not supplied to the ink heads 41 to 44. Therefore, when the liquid feed pump 73 is stopped, ink does not leak from the nozzles 51 to 58. Here, with the caps 111 to 114 attached to the nozzle surfaces 45 of the ink heads 41 to 44, the suction pumps 131 to 134 are driven to suck the ink in the ink heads 41 to 44, and the caps 111 to 11 It is discharged into 114. The ink in the caps 111 to 114 is further sucked by the suction pumps 131 to 134 and discharged to a waste liquid tank (not shown). In this way, the ink heads 41 to 44 are cleaned by the first cleaning operation.

During the first cleaning operation, the ink in the ink heads 41 to 44 is sucked, so that the ink heads 41 to 44 are depressurized. Therefore, as shown in FIG. 21, the second negative pressure opening ink chamber 174 becomes less than the opening pressure P10 together with the pressure of the ink heads 41 to 44. As a result, as shown in FIG. 14, the closing force F1 with respect to the first valve body 176 becomes less than the opening force F2, and the negative pressure opening valve mechanism 171 opens. During the first cleaning operation, the pressure release valve mechanism 181 is closed.

In the present embodiment, the second cleaning operation and the third cleaning operation are operations of performing so-called pressure cleaning on the ink heads 41 to 44. Here, the pressure cleaning is a cleaning in which ink is positively sent to the ink heads 41 to 44 while pressurizing the ink flow path 72. In this pressure cleaning, even when a plurality of nozzle rows 51a and 52a are present in the ink head 41 as in the present embodiment, for each nozzle row 51a and 52a (in other words, the ink supply system 61). , 62), the ink head 41 can be pressure-cleaned while pressurizing the ink flow path 72.

FIG. 22 is a schematic view showing the states of the ink supply systems 61 to 68 during the second cleaning operation and the third cleaning operation. In FIG. 22, the pressure of the ink flow path 72 is equal to or higher than the third pressure P3 and lower than the second pressure P2. In the second cleaning operation, as shown in FIG. 22, the liquid feed pump 73 is driven and the suction pumps 131 to 134 are stopped to perform pressure cleaning of the ink heads 41 to 44. The control of the ink supply systems 61 to 68 in the second cleaning operation is performed by the capping control unit 210, the cleaning liquid feed pump control unit 213, and the cleaning valve control unit 217 shown in FIG.

In the second cleaning operation, similarly to the first cleaning operation, the capping control unit 210 controls the capping mechanism 120 to attach the caps 111 to 114 to the nozzle surfaces 45 of the ink heads 41 to 44. Next, with the caps 111 to 114 attached to the nozzle surfaces 45 of the ink heads 41 to 44, the cleaning liquid feed pump control unit 213 drives the liquid feed pump 73 and stops the suction pumps 131 to 134. .. In the present embodiment, since the liquid feed pumps 73 are provided in each of the ink supply systems 61 to 68, there are a plurality of liquid feed pumps 73. The cleaning liquid feed pump control unit 213 may drive only the liquid feed pump 73 corresponding to the nozzles 51 to 58 to be cleaned among the plurality of liquid feed pumps 73.

Further, in the second cleaning operation, similarly to the first cleaning operation, the cleaning valve control unit 217 controls the relief valve 74 so that the relief valve 74 is in the second state S2 (see FIG. 8). Therefore, in the second cleaning operation, the relief valve 74 opens when the pressure in the ink flow path 72 becomes the second pressure P2 or higher.

In the second cleaning operation, as shown in FIG. 22, since the liquid feed pump 73 is driven, the ink in the ink tank 71 is supplied to the ink heads 41 to 44. At this time, the pressures of the ink flow path 72 and the ink heads 41 to 44 become high, and the pressure of the ink flow path 72 is, for example, a third pressure P3 or higher higher than the first pressure P1 and lower than the second pressure P2. It becomes. When the pressure of the ink flow path 72 becomes the third pressure P3 or higher, the negative pressure release valve mechanism 171 of the damper 75 is in a closed state, but the pressure release valve mechanism 181 is in an open state. Therefore, the ink in the ink tank 71 is supplied to the ink heads 41 to 44 through the pressure release valve mechanism 181, and the ink is ejected from the nozzles 51 to 58.

The ink discharged from the nozzles 51 to 58 is discharged to the caps 111 to 114. In the second cleaning operation, after the ink is discharged from the nozzles 51 to 58 to the caps 111 to 114, the suction pumps 131 to 134 are driven to discharge the ink in the caps 111 to 114 to the waste liquid tank. May be good.

In the second embodiment, when the pressure of the ink flow path 72 is in the vicinity of the third pressure P3 in the second cleaning operation, the relief valve 74 is in a closed state as shown in FIG. 22, so that the ink does not circulate. As described above, the ink heads 41 to 44 are pressure-cleaned by the second cleaning operation.

Although detailed illustration is omitted, the relief valve 74 opens when the ink flow path 72 is overpressurized and the pressure of the ink flow path 72 becomes the second pressure P2 or more during pressure cleaning. At this time, since the ink circulates including the ink tank 71, the ink flow path 72 can be depressurized. When the ink flow path 72 is depressurized and becomes lower than the second pressure P2, the relief valve 74 is closed.

In the third cleaning operation, the liquid feed pump 73 and the suction pumps 131 to 134 are appropriately driven to perform pressure cleaning of the ink heads 41 to 44. The control of the ink supply systems 61 to 68 in the third cleaning operation is performed by the capping control unit 210, the first cleaning pump control unit 215, the second cleaning pump control unit 216, and the cleaning valve control unit 217 shown in FIG. ..

In the third cleaning operation, the capping control unit 210 controls the capping mechanism 120 to attach the caps 111 to 114 to the nozzle surfaces 45 of the ink heads 41 to 44, as in the first cleaning operation. Next, as shown in FIG. 21, with the caps 111 to 114 attached to the nozzle surfaces 45 of the ink heads 41 to 44, the cleaning valve control unit 217 has the relief valve 74 as in the first cleaning operation. The relief valve 74 is controlled so as to be in the second state S2 (see FIG. 8). Therefore, in the third cleaning operation, the relief valve 74 opens when the pressure in the ink flow path 72 becomes equal to or higher than the second pressure P2.

Next, when the caps 111 to 114 are attached to the nozzle surfaces 45 of the ink heads 41 to 44 and the relief valve 74 is in the second state S2, the first cleaning pump control unit 215 is as shown in FIG. In addition, the suction pumps 131 to 134 are driven and the liquid feed pump 73 is stopped. By driving the suction pumps 131 to 134 in this way, the ink in the ink heads 41 to 44 is sucked and discharged from the nozzles 51 to 58 into the caps 111 to 114. By driving the suction pumps 131 to 134 in this way, the ink in the ink flow path 72 is sucked together with the ink in the ink heads 41 to 44. Therefore, the ink flow path 72 is depressurized.

In this way, the suction pumps 131 to 134 are driven by the first cleaning pump control unit 215 to reduce the pressure in the ink flow path 72, and then the second cleaning pump control unit 216 transfers the liquid feed pump as shown in FIG. While driving 73, the suction pumps 131 to 134 are stopped. By driving the liquid feed pump 73 while the ink flow path 72 is depressurized in this way, the amount of ink flowing through the ink flow path 72 per unit time increases, and the pressure in the ink flow path 72 increases rapidly. Will be expensive. When the pressure of the ink flow path 72 becomes the third pressure P3 or higher, the negative pressure release valve mechanism 171 of the damper 75 is in the closed state, but the pressure release valve mechanism 181 is in the open state. Therefore, the ink in the ink tank 71 is supplied to the ink heads 41 to 44 through the pressure release valve mechanism 181, and the ink is ejected from the nozzles 51 to 58. The ink discharged from the nozzles 51 to 58 is discharged to the caps 111 to 114.

In the third cleaning operation, after the ink is discharged from the nozzles 51 to 58 to the caps 111 to 114 by driving the liquid feeding pump 73, the suction pump is used to discharge the ink in the caps 111 to 114 to the waste liquid tank. 131-134 may be driven.

In the third cleaning operation, after the ink flow path 72 is depressurized, the liquid feed pump 73 is driven to perform pressure cleaning. Therefore, as compared with the second cleaning operation, the amount of ink ejected from the nozzles 51 to 58 per unit time is increased, so that the cleaning time can be shortened. As described above, the pressure cleaning of the ink heads 41 to 44 by the third cleaning operation is performed.

As shown in FIG. 17, the wiping operation is an operation of wiping the nozzle surfaces 45 of the ink heads 41 to 44. In the wiping operation, after cleaning the ink heads 41 to 44, the ink adhering to the nozzle surface 45 is wiped with a wiper. In the following description, the wiping operation performed after the pressure cleaning (specifically, the second cleaning operation and the third cleaning operation) will be described. The wiping control unit 219 shown in FIG. 18 controls the ink supply systems 61 to 68 in the wiping operation.

Since the wiping operation according to the present embodiment is performed after the pressure cleaning, the liquid feeding pump 73 is being driven as shown in FIG. 22. Therefore, the ink flow path 72 and the ink heads 41 to 44 are in a pressurized state, and the pressure of the ink flow path 72 is, for example, a third pressure P3 or higher. At the start of the wiping operation, ink is leaking from the nozzles 51 to 58 of the ink heads 41 to 44.

FIG. 23 is a schematic view showing the states of the ink supply systems 61 to 68 during the wiping operation. In the wiping operation, first, the wiping control unit 219 controls the capping mechanism 120 so that the caps 111 to 114 are separated from the nozzle surfaces 45 of the ink heads 41 to 44. After that, the wiping control unit 219 controls the head moving mechanism 30 so that the ink heads 41 to 44 are arranged above the wiper mechanism 140. Next, as shown in FIG. 23, the wiper control unit 219 drives the liquid feed pump 73, or while driving the liquid feed pump 73, with the pressure release valve mechanism 181 open, the nozzle The wiper mechanism 140 is controlled so that the surface 45 is wiped by the wiper 141.

Here, when wiping is performed after driving the liquid feeding pump 73, the wiping control unit 219 stops the liquid feeding pump 73, and after a predetermined time elapses, the wiper 141 wipes the nozzle surface 45. Controls the wiper mechanism 140. Although not shown here, when the liquid feed pump 73 is stopped, the pressure in the ink flow path 72 gradually decreases to less than the third pressure P3, so that the pressure release valve mechanism 181 is closed. At this time, the ink does not leak from the nozzles 51 to 58 of the ink heads 41 to 44. In the wiping operation according to the present embodiment, wiping is performed in a state where ink is leaking from the nozzles 51 to 58, in other words, in a state where the pressure release valve mechanism 181 is open. From the above, the above-mentioned predetermined time is preferably 0 or a time at which the pressure release valve mechanism 181 does not close. During the wiping operation, the negative pressure release valve mechanism 171 is in a closed state.

In the wiping operation according to the present embodiment, dust or the like is sucked from the nozzles 51 to 58 by wiping the nozzle surface 45 after driving the liquid feeding pump 73 or while driving the liquid feeding pump 73. Can be suppressed. Further, the ink leaking from the nozzles 51 to 58 can dissolve the ink solidified on the nozzle surface 45. Therefore, it is easy to wipe the ink solidified on the nozzle surface 45.

In the wiping operation, after wiping with the pressure release valve mechanism 181 open as described above, the wiper control unit 219 stops the liquid feed pump 73, and the pressure release valve mechanism 181 is activated. After closing, the wiper mechanism 140 may be controlled so as to wipe the nozzle surface 45 with the wiper 141 again. This makes it easier to remove the ink adhering to the nozzle surface 45. As described above, the wiping operation is performed.

In the circulation operation, the ink is circulated including the ink tank 71 during the printing standby, thereby suppressing the precipitation of the ink remaining in the ink flow path 72 and stirring the ink in the ink flow path 72. It is an operation to make it. Control of the ink supply systems 61 to 68 in the circulation operation is performed by the first circulation control unit 225 and the second circulation control unit 227 shown in FIG.

24 and 25 are schematic views showing the states of the ink supply systems 61 to 68 during the circulation operation. In addition, FIG. 24 and FIG. 25 show the time when the pressure of the ink flow path 72 is higher than the first pressure P1 and lower than the third pressure P3.

Caps 111 to 114 are attached to the ink heads 41 to 44 during printing standby. During printing standby, the liquid feed pump 73 is not driven, and the pressure in the ink flow path 72 is at least lower than the third pressure P3. Therefore, the pressure release valve mechanism 181 is closed during the printing standby. The negative pressure release valve mechanism 171 is also closed during the printing standby. Further, since the solenoid 155 of the relief valve 74 is turned off during the printing standby, the relief valve 74 is in the second state S2. Therefore, when the pressure of the ink flow path 72 becomes the second pressure P2 or more, the relief valve 74 is opened.

In the circulation operation, during the print standby, the first circulation control unit 225 first closes the relief valve 74 and pushes the liquid feed pump 73 in a state where the pressure release valve mechanism 181 is closed, as shown in FIG. 24. Drive. Here, closing the relief valve 74 means driving the liquid feed pump 73 to the extent that the relief valve 74 does not open. Here, the first circulation control unit 225 drives the liquid feed pump 73 so that the pressure in the ink flow path 72 does not exceed the second pressure P2. Further, in the present embodiment, the pressure release valve mechanism 181 is not opened during control by the first circulation control unit 225. Therefore, the first circulation control unit 225 drives the liquid feed pump 73 so that the pressure in the ink flow path 72 does not exceed the third pressure. Specifically, the first circulation control unit 225 may drive the liquid feed pump 73 so that the pressure in the ink flow path 72 is higher than the first pressure P1 and lower than the third pressure P3.

Next, the second circulation control unit 227 opens the relief valve 74 as shown in FIG. 25 after the control by the first circulation control unit 225. Specifically, the second circulation control unit 227 turns on the solenoid 155 of the relief valve 74 to switch from the second state S2 to the first state S1. As a result, the relief valve 74 is opened at the first pressure P1 or higher. Here, after the control by the first circulation control unit 225, the pressure of the ink flow path 72 is equal to or higher than the first pressure P1, so that the relief valve 74 is brought into the first state S1 by the second circulation control unit 227. As a result, the relief valve 74 is opened.

In this way, when the relief valve 74 is opened while the liquid feed pump 73 is driven by the second circulation control unit 227, the pressure in the ink flow path 72 is temporarily lowered. Therefore, as shown in FIG. 25, the ink flows back in the third forward flow path 81c of the ink flow path 72, that is, toward the return flow path 83. Therefore, the amount of ink circulating between the first forward flow path 81a, the second forward flow path 81b, and the return flow path 83 per unit time increases. Therefore, the time for circulating the ink can be shortened, and the ink can be agitated faster. As described above, the circulation operation is performed.

The maintenance operation is an operation performed during maintenance of the printer 100. Here, the maintenance of the printer 100 is an operation for confirming, for example, the state of the ink supply systems 61 to 68. The maintenance control unit 229 (see FIG. 18) controls the ink supply systems 61 to 68 in the maintenance operation.

FIG. 26 is a schematic view showing the states of the ink supply systems 61 to 68 during the maintenance operation. In the maintenance operation, the pressure of the ink flow path 72 is lowered to the head pressure of the ink tank 71. Therefore, first, as shown in FIG. 26, the maintenance control unit 229 stops the liquid feed pump 73 while the ink heads 41 to 44 are attached to the caps 111 to 114 during the printing standby. Further, the maintenance control unit 229 turns off the solenoid 155 of the relief valve 74 and sets the state of the relief valve 74 to the second state S2.

After that, as shown in FIG. 10, the user manually moves the button 168 of the relief valve 74 upward. Here, the user removes the cover 156b of the relief valve 74 from the valve body 151. As a result, the second bulb ink chamber 152b is opened downward. When the user manually pushes up the button 168, the button 168 pushes up the valve valve body 153. As a result, the valve valve body 153 opens the valve outlet 158a. Therefore, by moving the button 168 upward, the relief valve 74 is opened even when the pressure of the ink flow path 72 is lower than the first pressure P1. By opening the relief valve 74 by the button 168 in this way, the pressure in the ink flow path 72 is reduced to the head pressure of the ink tank 71. Then, the printer 100 is maintained with the pressure of the ink flow path 72 set to the water head pressure.

As described above, in the present embodiment, as shown in FIG. 4, one end of the first forward flow path 81a is connected to the ink tank 71 in which the ink is stored. The liquid feed pump 73 is connected to the other end of the first forward flow path 81a. One end of the second forward flow path 81b is connected to the liquid feed pump 73. One end of the third forward flow path 81c is connected to the other end of the second forward flow path 81b. One end of the return flow path 83 is connected to the other end of the second forward flow path 81b, and the other end is connected to the ink tank 71. The negative pressure release valve mechanism 171 is connected to the other end of the third forward flow path 81c and communicates with, for example, the nozzle 51 of the ink head 41. As shown in FIG. 13, the negative pressure release valve mechanism 171 provides a first inflow path 172 (see FIG. 12), a second negative pressure release ink chamber 174, a first valve body 176, and a first outflow path 177. Have. One end of the first inflow path 172 is connected to the other end of the third forward flow path 81c (see FIG. 4). In the second negative pressure release ink chamber 174, a communication port 174a to which the other end of the first inflow path 172 is connected is formed, and a first outlet 174c is formed. The first valve body 176 closes the communication port 174a when the pressure of the second negative pressure opening ink chamber 174 is higher than the first pressure P1, and the pressure of the second negative pressure opening ink chamber 174 is equal to or less than the first pressure P1. Sometimes the communication port 174a is opened. One end of the first outflow path 177 is connected to the first outflow port 174c, and the other end communicates with the nozzle 51.

In the present embodiment, when the pressure of the second negative pressure opening ink chamber 174 is higher than the opening pressure P10 and the closing force F1 with respect to the first valve body 176 is the opening force F2 or more, as shown in FIG. 13, the negative pressure is released. Since the valve mechanism 171 is closed, the ink in the ink tank 71 passes through the first forward flow path 81a, the second forward flow path 81b, and the return flow path 83 by driving the liquid feed pump 73, as shown in FIG. Return to the ink tank 71. Therefore, when the pressure of the second negative pressure opening ink chamber 174 is higher than the opening pressure P10, the ink circulates including the ink tank 71, so that the ink is agitated and the ink is less likely to settle. In this state, when ink is ejected from the nozzle 51 of the ink head 41 and the pressure of the second negative pressure opening ink chamber 174 becomes less than the opening pressure P10, as shown in FIG. 14, the closing force F1 with respect to the first valve body 176. Is less than the opening force F2, so that the negative pressure release valve mechanism 171 opens as shown in FIG. Therefore, the circulating and agitated ink in the ink tank 71 can be supplied to the nozzle 51 of the ink head 41. Therefore, it is possible to make it difficult to supply the ink in the ink tank 71 to the ink head 41 in a state where the ink in the ink tank 71 is precipitated.

In the present embodiment, as shown in FIG. 13, the negative pressure release valve mechanism 171 applies an elastic force to the first valve body 176 toward the side where the first valve body 176 closes the communication port 174a. It has a first negative pressure release spring 179a. Thereby, the magnitude of the closing force F1 can be adjusted according to the elastic force of the first negative pressure opening spring 179a. Therefore, the timing at which the negative pressure release valve mechanism 171 is released can be adjusted according to the elastic force of the first negative pressure release spring 179a.

In this embodiment, as shown in FIG. 13, the negative pressure release valve mechanism 171 has an atmosphere opening chamber 174b and a valve membrane 175. The atmosphere opening chamber 174b is arranged side by side with the second negative pressure opening ink chamber 174, and an atmosphere port 174d communicating with the atmosphere is formed. The valve membrane 175 partitions the second negative pressure opening ink chamber 174 and the atmosphere opening chamber 174b. The valve membrane 175 is formed of elastically deformable rubber based on the pressure of the second negative pressure opening ink chamber 174. As a result, the ink is ejected from the nozzle 51 of the ink head 41, so that the pressure of the second negative pressure opening ink chamber 174 becomes low and the valve film 175 becomes the second negative pressure opening ink chamber, as shown in FIG. It elastically deforms inside 174. As described above, by utilizing the property that the rubber forming the valve membrane 175 is elastically deformed, the valve membrane 175 can be easily deformed according to the pressure of the second negative pressure opening ink chamber 174. Further, in the present embodiment, since the air opening chamber 174b is open to the atmosphere, the valve membrane 175 is less likely to receive a force from the outside and is easily elastically deformed according to the pressure of the second negative pressure opening ink chamber 174.

Further, if the valve membrane 175 is a film, the film often has a multilayer structure, and there is a possibility that liquid pools may occur in the film. However, in the present embodiment, since the valve membrane 175 is formed of rubber, the rubber can have a single-layer structure. Therefore, the above-mentioned liquid pool is unlikely to occur. Further, since the valve membrane 175 is made of rubber, it is easy to realize a light-shielding property and the pressure resistance can be increased.

In the present embodiment, the valve membrane 175 is configured to come into contact with the first valve body 176 and force the first valve body 176 in a direction away from the communication port 174a with respect to the first valve body 176. There is. As a result, when the valve membrane 175 is elastically deformed according to the pressure of the second negative pressure opening ink chamber 174, the first valve body 176 can be easily moved according to the elastic deformation of the valve membrane 175.

In the present embodiment, the negative pressure release valve mechanism 171 has a second negative pressure release spring 179b that applies an elastic force to the valve membrane 175 so that the valve membrane 175 faces away from the communication port 174a. Thereby, the magnitude of the opening force F2 can be adjusted according to the elastic force of the second negative pressure opening spring 179b. Therefore, the timing at which the negative pressure release valve mechanism 171 is released can be adjusted according to the elastic force of the second negative pressure release spring 179b.

In the present embodiment, as shown in FIG. 4, the relief valve 74 is provided in the return flow path 83 so that the return flow path 83 can be opened and closed. As a result, the relief valve 74 may be opened when the ink is circulated, and the relief valve 74 may be closed when the ink is not circulated. Therefore, the circulation of ink including the ink tank 71 can be adjusted by opening and closing the relief valve 74.

In the present embodiment, as shown in FIG. 6, the relief valve 74 opens the return flow path 83 at the first pressure P1 or higher in the first state S1, and is in the first state as shown in FIG. In the second state S2, which is different from S1, the return flow path 83 is opened at a second pressure P2 or higher higher than the first pressure P1. In the present embodiment, the print valve control unit 223 controls the relief valve 74 so that the relief valve 74 is in the first state S1 at the time of printing, as shown in FIG. At the time of cleaning, the cleaning valve control unit 217 controls the relief valve 74 so that the relief valve 74 is in the second state S2, as shown in FIG. 22. The first pressure P1 is, for example, 30 kPa to 50 kPa. The second pressure P2 is 130 kPa to 170 kPa. In this way, in the relief valve 74, the return flow path 83 is opened by changing the state from the first state S1 to the second state S2 or from the second state S2 to the first state S1. You can change the timing.

In the present embodiment, the first pressure P1 of 30 kPa to 50 kPa is close to the pressure of the second negative pressure open ink chamber 174 after the ink is ejected at the time of printing. The negative pressure release valve mechanism 171 opens when the pressure in the second negative pressure release ink chamber 174 is equal to or lower than the first pressure P1. Therefore, during printing, as shown in FIGS. 19 and 20, the relief valve 74 is set to the first state S1 by the printing valve control unit 223, so that the relief valve 74 is linked with the opening and closing of the negative pressure release valve mechanism 171 to relieve the relief valve 74. The valve 74 can be opened and closed.

Further, for example, during pressure cleaning, the ink flow path 72 may be overpressurized. For example, in the ink flow path 72, the maximum pressure that can be appropriately used is 130 kPa to 170 kPa of the second pressure P2. Therefore, at the time of pressure cleaning, as shown in FIG. 22, the relief valve 74 is brought into the second state S2 by the cleaning valve control unit 217. As a result, when the pressure of the ink flow path 72 becomes equal to or higher than the second pressure P2 and the pressure of the ink flow path 72 becomes too high, the relief valve 74 is opened. When the relief valve 74 is opened, the ink flow path 72 is depressurized. Therefore, it is possible to prevent the pressure of the ink flow path 72 from becoming too high (in other words, the second pressure P2 or higher) during pressure cleaning.

In the present embodiment, as shown in FIG. 6, in the relief valve 74, in the first valve ink chamber 152aa, a valve inflow port 157a to which a valve inflow path 157 in which ink flows is connected and a valve outflow port 158a are provided. It is formed. The valve outflow path 159 from which ink flows out is connected to the valve outflow port 158a. The valve valve body 153 can open and close the valve outlet 158a. The first spring 161 applies an elastic force to the valve body 153 in the direction toward the valve outlet 158a. The valve rod 154 contacts the valve valve body 153 and opens and closes the valve valve body 153 with respect to the valve outlet 158a. The solenoid 155 has a solenoid main body 165 and a shaft core 166 that is movably inserted into the solenoid main body 165 with respect to the solenoid main body 165 and can come into contact with the valve rod 154. In this embodiment, the solenoid 155 is a so-called normally closed type. The second spring 162 applies an elastic force to the shaft core 166 in a direction away from the solenoid main body 165. When the solenoid 155 is ON, the position of the shaft core 166 is fixed at a position where the valve rod 154 and the shaft core 166 are separated from each other. When the solenoid 155 is OFF, the shaft core 166 is configured to be movable with respect to the solenoid main body 165 in a state where the valve rod 154 and the shaft core 166 are in contact with each other. The first state S1 shown in FIG. 6 is a state in which the solenoid 155 is ON and the position of the shaft core 166 is fixed at a position where the valve rod 154 and the shaft core 166 are separated from each other. Here, in the first state S1, since the valve rod 154 and the shaft core 166 are separated from each other, the shaft core 166 is not pushed up by the valve rod 154. Therefore, in the first state S1, the position of the shaft core 166 is fixed. In the second state S2 shown in FIG. 8, the solenoid 155 is OFF, the valve rod 154 and the shaft core 166 are in contact with each other, and the shaft core 166 is movable with respect to the solenoid body 165. .. Here, in the second state S2, the shaft core 166 is pushed up by the valve rod 154, so that the shaft core 166 can move with respect to the solenoid main body 165.

As a result, as shown in FIG. 7, when the relief valve 74 is in the first state S1 and the solenoid 155 is ON, the valve valve body 153 is pushed by the elastic force of the first spring 161. The outlet 158a is closed. Here, when the pressure of the valve inflow path 157 is equal to or higher than the first pressure P1, the valve body 153 opens the valve outlet 158a and opens the relief valve 74 against the elastic force of the first spring 161. be able to. On the other hand, as shown in FIG. 9, when the relief valve 74 is in the second state S2 and the solenoid 155 is OFF, the valve valve body 153 is the sum of the elastic forces of both the first spring 161 and the second spring 162. The valve outlet 158a is closed while being pushed by the elastic force. Here, when the pressure of the valve inflow path 157 is higher than the first pressure P1 and is equal to or higher than the second pressure P2, the valve valve body 153 resists the total elastic force of the first spring 161 and the second spring 162. The valve outlet 158a can be opened and the relief valve 74 can be opened. By configuring the relief valve 74 as in the present embodiment, the timing at which the return valve 83 is opened can be changed according to the pressure of the ink flow path 72.

As described above, in the present embodiment, the solenoid 155 is a so-called normally closed type. However, the solenoid 155 may be a so-called normally open type. When the solenoid 155 is a normally open type, the second spring 162 applies an elastic force to the shaft core 166 in a direction approaching the solenoid body 165 (for example, upward in FIG. 6). In this case, the second spring 162 is interposed between the solenoid main body 165 and the flange 167 of the shaft core 166, and is in an extended state when the solenoid 155 is ON. Then, when the solenoid 155 is OFF, the shaft core 166 moves upward due to the contracting force of the second spring 162. When the solenoid 155 is a normally open type, the position of the shaft core 166 is fixed at a position where the valve rod 154 and the shaft core 166 are separated from each other when the solenoid 155 is OFF. (See FIG. 6). When the solenoid 155 is ON, the shaft core 166 is configured to be movable with respect to the solenoid main body 165 in a state where the valve rod 154 and the shaft core 166 are in contact with each other, and the second state S2 (see, for example, FIG. 8) Become. As described above, even if the solenoid 155 is a normally open type, the same effect as that of the normally closed type can be obtained.

In the present embodiment, as shown in FIG. 4, the pressure release valve mechanism 181 is connected to the other end of the third forward flow path 81c and communicates with the nozzle 51. In the pressure release valve mechanism 181, one end of the second inflow path 182 is connected to the other end of the third forward flow path 81c. As shown in FIG. 12, in the pressurized open ink chamber 183, a second inflow port 183a to which the other end of the second inflow path 182 is connected is formed, and a second outflow port 183b is formed. The second valve body 185 closes the second inflow port 183a when the pressure in the second inflow path 182 is higher than the first pressure P1 and lower than the third pressure P3, which is lower than the second pressure P2, and the second. When the pressure in the inflow path 182 is equal to or higher than the third pressure P3, the second inflow port 183a is opened. One end of the second outflow path 186 is connected to the second outflow port 183b, and the other end of the second outflow path 186 communicates with the nozzle 51. In the pressure release valve mechanism 181, when the ink head 41 is pressure-cleaned, the second valve body 185 opens the second inflow port 183a (see FIG. 22), and the ink head 41 is not pressure-cleaned. , The second valve body 185 is configured to close the second inflow port 183a (see FIG. 19). In other words, the second valve body 185 is configured to open the second inflow port 183a when cleaning the ink head 41 and close the second inflow port 183a when not cleaning the ink head 41. ing.

As a result, during pressure cleaning, as shown in FIG. 22, when the liquid feed pump 73 is driven to pressurize the ink flow path 72 and the pressure of the ink flow path 72 becomes the third pressure P3 or higher. In addition, the pressure release valve mechanism 181 can be opened while the negative pressure release valve mechanism 171 is closed. Therefore, during pressure cleaning, the pressure of the ink flow path 72 is set to the third pressure P3 or higher, and the ink in the ink tank 71 is supplied to the ink head 41 through the pressure release valve mechanism 181 while cleaning the ink head 41. It can be performed. Further, for example, during printing other than pressure cleaning, the pressure of the ink flow path 72 is lower than the third pressure P3. Therefore, at times other than pressure cleaning, the pressure release valve mechanism 181 can be closed as shown in FIG.

In the present embodiment, as shown in FIG. 13, one damper main body 170 is provided with a negative pressure release valve mechanism 171 and a pressure release valve mechanism 181. At least a part of the second negative pressure release ink chamber 174 and at least a part of the pressure release ink chamber 183 are formed in the damper main body 170. As a result, the number of parts related to the damper 75 can be reduced.

In the present embodiment, the negative pressure release valve mechanism 171 and the pressure release valve mechanism 181 are arranged side by side in the vertical direction. Specifically, the negative pressure release valve mechanism 171 is arranged above the pressure release valve mechanism 181. As a result, the length of the damper 75 in the width direction can be shortened, so that it is possible to prevent the printer 100 from becoming larger in the horizontal direction.

In the present embodiment, the central axis L1 of the first valve body 176 of the negative pressure release valve mechanism 171 and the central axis L2 of the second valve body 185 of the pressure release valve mechanism 181 are substantially parallel and substantially parallel to each other. It is horizontal. As a result, the first valve body 176 and the second valve body 185 can be opened and closed by elastically deforming in the same direction and in the horizontal direction. Therefore, as compared with the case of opening and closing by elastically deforming in the vertical direction, for example, it is possible to make it less susceptible to the influence of gravity.

In the present embodiment, the negative pressure release valve mechanism 171 has a first valve seat 176a with which the first valve body 176 comes into contact when the first valve body 176 closes the communication port 174a. The pressure release valve mechanism 181 has a second valve seat 185a with which the second valve body 185 comes into contact when the second valve body 185 closes the second inflow port 183a. The first inflow port 173a is arranged on one side (right side in FIG. 13) of the first valve seat 176a, and the first outlet 174c is arranged on the other side (left side in FIG. 13) of the first valve seat 176a. There is. The second inflow port 183a is arranged on one side of the second valve seat 185a, and the second outlet 183b is arranged on the other side of the second valve seat 185a. As a result, in the negative pressure release valve mechanism 171 and the pressure release valve mechanism 181, ink flows from one side to the other side of the first valve seat 176a and the second valve seat 185a, respectively. Therefore, in the negative pressure release valve mechanism 171 and the pressure release valve mechanism 181, the ink flow direction can be the same, and a simple configuration can be obtained. Therefore, it is possible to prevent the configuration of the damper 75 from becoming complicated.

In the present embodiment, the ink head 41 has a nozzle surface 45 on which nozzles 51 and 52 are formed. As shown in FIG. 16, the printer 100 includes a cap 111 that can be attached to the nozzle surface 45 so as to cover the nozzles 51 and 52, and a suction pump 131 connected to the cap 111. When cleaning the ink head 41, the cleaning suction pump control unit 211 of the control device 200 drives the suction pump 131 and feeds the liquid with the cap 111 attached to the nozzle surface 45, as shown in FIG. Stop the pump 73. As a result, the ink in the ink head 41 is sucked by the drive of the suction pump 131, so that the ink in the ink head 41 can be discharged to the cap 111.

In the present embodiment, when cleaning the ink head 41, the cleaning liquid feed pump control unit 213 drives the liquid feed pump 73 with the cap 111 attached to the nozzle surface 45 as shown in FIG. 22. , Stop the suction pump 131. As a result, the ink head 41 can be cleaned while driving the liquid feed pump 73 to supply the ink in the ink tank 71 to the ink head 41. When the suction pump 131 is driven to perform the ink heads 41 to 44, the cleaning target is selectively determined for each ink head 41 to 44. In the cleaning in which the liquid feed pump 73 is driven, unlike the case in which the suction pump 131 is driven to clean the ink head 41, it is possible to selectively determine the cleaning target for each of the ink supply systems 61 to 68. can.

In the present embodiment, the first cleaning pump control unit 215 drives the suction pump 131 when the ink head 41 is cleaned, with the cap 111 attached to the nozzle surface 45, as shown in FIG. The second cleaning pump control unit 216 drives the liquid feed pump 73 as shown in FIG. 22 after the suction pump 131 is driven by the first cleaning pump control unit 215. By driving the suction pump 131 by the first cleaning pump control unit 215 in this way, the ink in the ink flow path 72 is sucked, so that the ink flow path 72 can be depressurized. By driving the liquid feed pump 73 by the second cleaning pump control unit 216 while the ink flow path 72 is depressurized in this way, the amount of ink flowing through the ink flow path 72 per unit time increases. Therefore, since the amount of ink ejected from the nozzle 51 per unit time increases, the cleaning time can be shortened.

In this embodiment, as shown in FIG. 17, the wiper mechanism 140 has a wiper 141 that wipes the nozzle surface 45. As shown in FIG. 23, the wiper control unit 219 has the nozzle surface after driving the liquid feed pump 73 or while driving the liquid feed pump 73 while the pressure release valve mechanism 181 is open. The wiper mechanism 140 is controlled so that the wiper 45 is wiped by the wiper 141. As a result, it is possible to prevent dust and the like from being sucked from the nozzle 51 by wiping the nozzle surface 45 after driving the liquid feeding pump 73 or while driving the liquid feeding pump 73. Further, by driving the liquid feeding pump 73, ink leaks from the nozzle 51. Therefore, the ink leaking from the nozzle 51 during wiping can dissolve the solidified ink on the nozzle surface 45. Therefore, it is easy to wipe the ink solidified on the nozzle surface 45.

In the present embodiment, as shown in FIG. 24, the first circulation control unit 225 closes the relief valve 74 and drives the liquid feed pump 73 in a state where the pressure release valve mechanism 181 is closed. The second circulation control unit 227 opens the relief valve 74 as shown in FIG. 25 after the control by the first circulation control unit 225. In this way, the pressure of the ink flow path 72 can be increased to such an extent that the pressure release valve mechanism 181 does not open by the control by the first circulation control unit 225. By opening the relief valve 74 in a state where the pressure of the ink flow path 72 is increased to such that the pressure release valve mechanism 181 does not open, the pressure of the ink flow path 72 is temporarily lowered. Therefore, the ink in the third forward flow path 81c of the ink flow path 72 flows in the reverse flow, that is, toward the return flow path 83. Therefore, the amount of ink circulating between the first forward flow path 81a, the second forward flow path 81b, and the return flow path 83 per unit time increases. Therefore, the time for circulating the ink can be shortened, and the ink can be agitated faster.

In the present embodiment, in the negative pressure release valve mechanism 171, the first valve body 176 opens and closes the communication port 174a. However, in the negative pressure release valve mechanism 171, the first valve body 176 may open and close the first outlet 174c (see FIG. 12).

In the pressure release valve mechanism 181 the second valve body 185 opened and closed the second inflow port 183a. However, in the pressurized release valve mechanism 181 the second valve body 185 may open and close the second outlet 183b (see FIG. 12).

The printer 100 according to the first embodiment has been described above. The inkjet printer proposed here is not limited to the printer 100 according to the first embodiment, and can be implemented in various other forms. Next, other embodiments will be briefly described. In the following description, the same reference numerals will be used for configurations similar to those already described, and the description thereof will be omitted.

<Second Embodiment>
Next, the printer according to the second embodiment will be described. FIG. 27 is a front view of the damper 75A according to the second embodiment. FIG. 28 is a cross-sectional view of the damper 75A on line XXVIII-XXVIII of FIG. As shown in FIG. 27, the printer according to this embodiment includes a damper 75A. Similar to the damper 75 of the first embodiment, the damper 75A has a damper main body 170, a negative pressure release valve mechanism 171 and a pressure release valve mechanism 181. As shown in FIG. 28, the negative pressure release valve mechanism 171 has a first negative pressure release ink chamber 173 and a second negative pressure release ink chamber 174.

In the present embodiment, in the negative pressure release valve mechanism 171, a part of the second negative pressure release ink chamber 174 is opened. Here, the opening is formed on the side of the second negative pressure opening ink chamber 174 opposite to the first negative pressure opening ink chamber 173 side. A valve membrane 175 is provided in the opened portion of the second negative pressure opening ink chamber 174. The valve membrane 175 covers the opened portion of the second negative pressure release ink chamber 174. The valve membrane 175 is formed of a flexible member, for example, rubber. However, in the present embodiment, the valve membrane 175 may be formed of a film.

The second negative pressure release ink chamber 174 is formed with a communication port 174a that communicates with the first negative pressure release ink chamber 173. When viewed from the opening direction of the second negative pressure release ink chamber 174, that is, the direction in which the valve membrane 175 is provided, the communication port 174a is the central portion (specifically, the center) of the second negative pressure release ink chamber 174. Is formed in. The ink flowing out from the first negative pressure opening ink chamber 173 flows into the communication port 174a. Ink flows into the second negative pressure open ink chamber 174 through the communication port 174a.

In the present embodiment, an inclined surface 274 is formed in the second negative pressure opening ink chamber 174. The inclined surface 274 is formed at a position facing the valve membrane 175, and more specifically, the inclined surface 274 is formed on a surface forming a second negative pressure release ink chamber 174 facing the valve membrane 175. Here, as shown in FIG. 27, the inclined surface 274 is an annular surface that surrounds the communication port 174a. As shown in FIG. 28, the inclined surface 274 is inclined so as to approach the valve membrane 175 as the distance from the communication port 174a increases.

The second negative pressure release ink chamber 174 is formed with a first outlet 174c through which the ink in the second negative pressure release ink chamber 174 flows out. Here, the first outlet 174c is formed on the inclined surface 274. In this embodiment, the damper 75A is installed in the orientation shown in FIG. 28. Therefore, in the state where the damper 75A is installed in the orientation shown in FIG. 28, the first outlet 174c is formed in the lower part of the second negative pressure opening ink chamber 174.

In the present embodiment, the flow path groove 275 is formed in the second negative pressure opening ink chamber 174. The flow path groove 275 is formed on the surface of the second negative pressure release ink chamber 174 facing the valve membrane 175. The flow path groove 275 is a groove connected to the first outlet 174c. The flow path groove 275 is connected to the first outlet 174a. As shown in FIG. 27, the flow path groove 275 is a groove extending from the first outlet 174c toward the communication port 174a. Here, the flow path groove 275 is not directly connected to the communication port 174a, but may be directly connected to the communication port 174a. That is, the flow path groove 275 may be a groove that directly connects the communication port 174a and the first outlet 174c. In the present embodiment, the flow path groove 275 is a linear groove, but at least a part thereof may be bent. The flow path groove 275 is configured so that when the valve membrane 175 bends inward of the second negative pressure release ink chamber 174, it is not blocked by the valve membrane 175.

In this embodiment, for example, the ink may be mixed with air bubbles. When air bubbles are mixed in the ink in this way, a higher negative pressure can be applied to the second negative pressure open ink chamber 174 in order to discharge the air bubbles from the second negative pressure open ink chamber 174 for cleaning or the like. possible. In this way, by applying a higher negative pressure to the second negative pressure opening ink chamber 174, the valve film 175 bends toward the inside of the second negative pressure opening ink chamber 174, and the second negative pressure opening ink chamber 174 As the volume becomes smaller, the ink mixed with air bubbles can be easily discharged from the first outlet 174c.

However, when a high negative pressure is applied to the second negative pressure opening ink chamber 174, the valve membrane 175 bends more in the second negative pressure opening ink chamber 174, and the valve membrane 175 becomes the surface of the second negative pressure opening ink chamber 174. May block the second outlet 174c. Even in such a case, the flow path groove 275 is not blocked by the greatly bent valve membrane 175. Therefore, the ink that has flowed into the second negative pressure open ink chamber 174 from the communication port 174a flows to the first outlet 174c through the flow path groove 275, and can be discharged from the first outlet 174c. Therefore, even when a high negative pressure is applied to the second negative pressure opening ink chamber 174 and the valve membrane 175 comes into contact with the surface forming the second negative pressure opening ink chamber 174, the communication port 174a is provided by the flow path groove 275. It is possible to secure a flow path from the first outlet to the first outlet 174c.

In the present embodiment, the valve membrane 175 is formed of elastically deformable rubber based on the pressure of the second negative pressure release ink chamber 174. Therefore, when a high negative pressure is applied to the second negative pressure release ink chamber 174, The valve membrane 175 easily comes into contact with the surface forming the second negative pressure release ink chamber 174. However, since the flow path groove 275 is formed in the second negative pressure opening ink chamber 174, even if the valve membrane is made of rubber 175, the flow from the communication port 174a to the first outlet 174c by the flow path groove 275 The road can be secured. Therefore, the flow path groove 275 is particularly useful in the rubber valve membrane 175.

In the present embodiment, the first outlet 174c is formed on the inclined surface 274 of the second negative pressure release ink chamber 174. Therefore, since the first outlet 174c is arranged at a position closer to the valve membrane 175 than the communication port 174a, when a high negative pressure is applied to the second negative pressure opening ink chamber 174, the valve membrane 175 comes into contact with the inclined surface 274. easy. However, since the flow path groove 275 is formed in the second negative pressure opening ink chamber 174, even when the first outlet 174c is formed on the inclined surface 274, the flow path groove 275 allows the communication port 174a to be formed. It is possible to secure a flow path toward the first outlet 174c. Therefore, the flow path groove 275 is particularly useful when the first outlet 174c is formed on the inclined surface 274.

In the present embodiment, as shown in FIG. 28, the first outlet 174c is formed in the lower part of the second negative pressure opening ink chamber 174. As a result, when the damper 75A is installed, when the ink in the second negative pressure release ink chamber 174 is settled, it is formed around the first outlet 174c formed in the lower part of the second negative pressure release ink chamber 174. Easy to settle. Therefore, the precipitated ink can be easily discharged from the first outlet 174c.

<Third Embodiment>
Next, the printer according to the third embodiment will be described. 29 and 30 are perspective views of the damper 75B according to the third embodiment. FIG. 30 is a perspective view seen from the rear side in FIG. 29, which is a partially enlarged view. FIG. 31 is a partial cross-sectional view of the damper 75B on the XXXI-XXXI line of FIG. As shown in FIG. 29, the printer according to this embodiment includes a damper 75B. Similar to the damper 75 of the first embodiment, the damper 75B has a damper main body 170, a negative pressure release valve mechanism 171 and a pressure release valve mechanism 181. The damper 75B further has a foreign matter removing mechanism 280, and the foreign matter removing mechanism 280 is provided in the printer according to the present embodiment.

For example, ink may be mixed with foreign matter such as dust. The foreign matter removing mechanism 280 is a mechanism for removing foreign matter contained in the ink in the damper 75B. In the present embodiment, the foreign matter removing mechanism 280 is provided on the damper main body 170 together with the negative pressure release valve mechanism 171 and the pressure release valve mechanism 181. The foreign matter removing mechanism 280 is provided on the upstream side of the negative pressure release valve mechanism 171 and the pressure release valve mechanism 181, and the ink that has passed through the foreign matter removal mechanism 280 is the negative pressure release valve mechanism 171 or the pressure release valve. It flows through any of the mechanisms 181. In the present embodiment, although detailed illustration is omitted, the foreign matter removing mechanism 280 includes a third forward flow path 81c (see FIG. 4) of the forward flow path 81 and a first inflow path 172 of the negative pressure release valve mechanism 171 (see FIG. 12). ), And the second inflow passage 182 (see FIG. 12) of the pressure release valve mechanism 181.

As shown in FIG. 31, the foreign matter removing mechanism 280 includes a foreign matter removing flow path 281, a foreign matter removing chamber 282, a removing inlet 283, a removing outlet 284, a trapping body 285, a film 286, and a reinforcing member 287. It has.

The removal flow path 281 is a flow path connecting the third forward flow path 81c (see FIG. 4) of the forward flow path 81 and the foreign matter removing chamber 282. Here, the removal flow path 281 is provided in the damper main body 170, and one end of the removal flow path 281 communicates with the damper inflow port 170a of the damper main body 170, and the third forward flow passes through the damper inflow port 170a. It is connected to road 81c (see FIG. 4). The other end of the removal flow path 281 is connected to the foreign matter removal chamber 282.

As shown in FIG. 31, the foreign matter removing chamber 282 has a predetermined space, and ink flows in and out. The foreign matter contained in the ink is removed in the foreign matter removing chamber 282. The foreign matter removing chamber 282 is smaller than the second negative pressure release ink chamber 174 (see FIG. 13), but may be larger. Further, the foreign matter removing chamber 282 may be smaller or larger than the first negative pressure release ink chamber 173 (see FIG. 13). In the present embodiment, the foreign matter removing chamber 282 is formed with a removing inlet 283 and a removing outlet 284.

The removal inflow port 283 is a portion where ink flows into the foreign matter removing chamber 282. In the present embodiment, the removal inflow port 283 is connected to the removal flow path 281 and is connected to the third forward flow path 81c (see FIG. 4) of the forward flow path 81 via the removal flow path 281. The ink that has flowed through the third forward flow path 81c flows into the foreign matter removing chamber 282 through the removal inflow port 283.

The removal outlet 284 is a portion where the ink flows out from the foreign matter removing chamber 282. In the present embodiment, the removal outlet 284 is connected to the first inflow passage 172 of the negative pressure release valve mechanism 171 and the second inflow passage 182 (see FIG. 12) of the pressure release valve mechanism 181. The ink flowing out from the removal outlet 284 flows into the first inflow path 172 or the second inflow path 182.

As shown in FIG. 31, the trapping body 285 is provided in the foreign matter removing chamber 282, and allows ink to pass through and captures foreign matter. The trap 285 is realized, for example, by a porous filter. The porous filter is realized, for example, in the form of a metal mesh. Ink passes through this porous filter, but foreign matter does not easily pass through. The trapping body 285 is not limited to the filter, and the material forming the trapping body 285 is not limited to the metal. The capture body 285 is arranged between the removal inlet 283 and the removal outlet 284, and divides the foreign matter removal chamber 282 into the removal inlet 283 side and the removal outlet 284 side.

Here, the portion of the foreign matter removing chamber 282 on the removal inflow port 283 side of the trapping body 285 is referred to as an inflow foreign matter removing chamber 282a. The portion of the foreign matter removing chamber 282 on the removal outlet 284 side of the trapping body 285 is referred to as an outflow foreign matter removing chamber 282b. The ink in the inflowing foreign matter removing chamber 282a passes through the trapping body 285 and flows into the outflowing foreign matter removing chamber 282b.

An opening 282c is formed in a part of the foreign matter removing chamber 282. In the present embodiment, the opening 282c is formed in the outflow foreign matter removing chamber 282b of the foreign matter removing chamber 282. The film 286 is provided in the damper main body 170 so as to cover the opening 282c of the foreign matter removing chamber 282. The film 286 is configured to bend inward or outward of the foreign matter removing chamber 282 in response to the pressure of the foreign matter removing chamber 282.

In the present embodiment, the reinforcing member 287 reinforces the film 286 and suppresses the bending of the film 286. The reinforcing member 287 is fixed to the film 286 inside the foreign matter removing chamber 282 rather than the film 286. Here, the reinforcing member 287 is arranged in the outflow foreign matter removing chamber 282b. The reinforcing member 287 has a shape that matches the opening 282c of the foreign matter removing chamber 282, and is fitted into the opening 282c. The material for forming the reinforcing member 287 is not particularly limited, but for example, the reinforcing member 287 is made of resin.

In the present embodiment, as shown in FIG. 30, the film 286 and the reinforcing member 287 are welded and fixed. Therefore, a welding mark 288 is formed between the film 286 and the reinforcing member 287. The number, shape and position of the welding marks 288 are not particularly limited. Here, there are six welding marks 288, which are linear marks. The six welding marks 288 extend radially from the center of the reinforcing member 287.

In the present embodiment, the film 286 and the damper body 170 are welded and fixed. Therefore, another welding mark 289 is formed between the film 286 and the damper main body 170. The other welding marks 289 are formed in the portion of the damper body 170 around the opening 282c along the shape of the opening 282c of the foreign matter removing chamber 282. However, the number, shape and position of the other welding marks 289 are not particularly limited.

In the present embodiment, the ink in the third forward flow path 81c (see FIG. 4) of the forward flow path 81 flows into the damper 75B. As shown in FIG. 31, in the damper 75B, the ink flows through the removal flow path 281 through the damper inflow port 170a, and flows from the removal inflow port 283 into the inflowing foreign matter removing chamber 282a of the foreign matter removing chamber 282. The ink in the inflowing foreign matter removing chamber 282a passes through the trapping body 285 and flows to the outflowing foreign matter removing chamber 282b. At this time, when the ink in the inflowing foreign matter removing chamber 282a is mixed with the foreign matter, the foreign matter does not pass through the trapping body 285 and is caught by the trapping body 285. Therefore, it is difficult for foreign matter to mix with the ink in the outflow foreign matter removing chamber 282b. The ink in the outflow foreign matter removing chamber 282b flows out from the removal outflow port 284, and is either the first inflow path 172 of the negative pressure release valve mechanism 171 or the second inflow path 182 of the pressure release valve mechanism 181 (see FIG. 12). Flow to.

For example, when the pressure of the foreign matter removing chamber 282 is high, the film 286 bends to the outside of the foreign matter removing chamber 282, and when the pressure of the foreign matter removing chamber 282 is low, the film 286 bends to the inside of the foreign matter removing chamber 282. By repeatedly bending the film 286 outward or inward in this way, the film 286 may be damaged. However, in the present embodiment, the reinforcing member 287 is fixed to the film 286. Therefore, the width of the deflection of the film 286 is limited by the reinforcing member 287, and the film 286 can be made difficult to bend. Therefore, it is possible to prevent the film 286 from being damaged even when a high pressure or a low pressure is repeatedly applied to the foreign matter removing chamber 282.

In the present embodiment, as shown in FIG. 30, a welding mark 288 is formed between the film 286 and the reinforcing member 287. As a result, since the film 286 and the reinforcing member 287 are welded and fixed, it is possible to make it difficult for the reinforcing member 287 to be removed from the film 286.

Similarly, another welding mark 289 is formed between the film 286 and the damper body 170. As a result, since the film 286 and the damper main body 170 are welded and fixed, it is possible to make it difficult for the film 286 to be removed from the damper main body 170.

In the ink flow path 72 (see FIG. 4) of the ink supply system provided with the dampers 75A and 75B in the second embodiment and the third embodiment, the return flow path 83 (see FIG. 4) may be omitted. That is, the ink flow path 72 connected to the dampers 75A and 75B is not limited to the one in which the ink circulates.

41-44 Ink head 45 Nozzle surface 51-58 Nozzle 71 Ink tank 73 Liquid feed pump 74 Relief valve 81a First forward flow path 81b Second forward flow path 81c Third forward flow path 83 Return flow path 100 Printer (inkjet printer)
152aa 1st bulb ink chamber (bulb ink chamber)
171 Negative pressure release valve mechanism 172 1st inflow path 174 2nd negative pressure release ink chamber (negative pressure release ink chamber)
174a 1st inflow port 174c 1st outflow port 175 Valve membrane 176 1st valve body 177 1st outflow passage 181 Pressurized release valve mechanism 200 Control device 211 Cleaning suction pump control unit 213 Cleaning liquid feed pump control unit 215 First cleaning pump control Unit 216 Second cleaning pump control unit 217 Cleaning valve control unit 219 Wiping control unit 221 Printing pump control unit 223 Printing valve control unit 225 First circulation control unit 227 Second circulation control unit

Claims (34)

Ink tank where ink is stored and
An ink head with a nozzle that ejects ink,
The first forward flow path, one end of which is connected to the ink tank,
With the liquid feed pump connected to the other end of the first forward flow path,
A second forward flow path, one end of which is connected to the liquid feed pump,
A third forward flow path whose one end is connected to the other end of the second forward flow path,
A negative pressure release valve mechanism that is connected to the other end of the third forward flow path and communicates with the nozzle.
A return flow path in which one end is connected to the other end of the second forward flow path and the other end is connected to the ink tank.
With
The negative pressure release valve mechanism is
A first inflow path whose one end is connected to the other end of the third forward flow path,
A first negative pressure open ink chamber formed with a first inflow port to which the other end of the first inflow path is connected, and
A second negative pressure open ink chamber communicating with the first negative pressure open ink chamber through a communication port and forming a first outlet, and a second negative pressure open ink chamber.
A first outflow path, one end of which is connected to the first outlet and the other end of which communicates with the nozzle.
A first valve body that is provided so that the communication port can be opened and closed and opens the communication port when the pressure of the second negative pressure opening ink chamber is equal to or lower than a predetermined opening pressure.
Has an inkjet printer. The negative pressure release valve mechanism has a first negative pressure release spring that applies an elastic force to the first valve body toward the side where the first valve body closes the communication port. Inkjet printer described in. The negative pressure release valve mechanism is
An atmospheric opening chamber, which is arranged side by side with the second negative pressure opening ink chamber and has an atmospheric port communicating with the atmosphere,
A valve membrane that separates the second negative pressure open ink chamber and the atmospheric open chamber,
Have,
The inkjet printer according to claim 1 or 2, wherein the valve membrane is formed of rubber that is elastically deformable based on the pressure of the second negative pressure opening ink chamber. The third aspect of the present invention, wherein the valve membrane abuts on the first valve body and exerts a force on the first valve body in a direction in which the first valve body separates from the communication port. Inkjet printer described. The negative pressure release valve mechanism according to claim 3 or 4, wherein the negative pressure release valve mechanism has a second negative pressure release spring that applies an elastic force to the valve membrane so that the valve membrane faces away from the communication port. Inkjet printer. The communication port is formed in the second negative pressure open ink chamber, and is formed.
A part of the second negative pressure release ink chamber is opened,
A valve membrane is provided in the opened portion of the second negative pressure release ink chamber.
The inkjet printer according to any one of claims 1 to 5, wherein a flow path groove connecting to the first outlet is formed in the second negative pressure release ink chamber. The inkjet printer according to claim 6, wherein the valve membrane is formed of rubber that is elastically deformable based on the pressure of the second negative pressure opening ink chamber. The inkjet printer according to claim 6 or 7, wherein the first outlet is formed in the lower part of the second negative pressure release ink chamber. The second negative pressure release ink chamber is formed at a position facing the valve membrane, and has an inclined surface that is inclined so as to approach the valve membrane as the distance from the communication port increases.
The inkjet printer according to any one of claims 6 to 8, wherein the first outlet is formed on the inclined surface. It is connected to one end of the first inflow path and is provided with a foreign matter removing mechanism for removing foreign matter contained in ink.
The foreign matter removing mechanism is
A foreign matter removal chamber with a partial opening and
A removal inlet formed in the foreign matter removing chamber and allowing ink to flow into the foreign matter removing chamber,
A removal outlet formed in the foreign matter removing chamber and allowing ink to flow out of the foreign matter removing chamber,
A catching body that divides the foreign matter removing chamber into the removing inlet side and the removing outlet side, and captures foreign matter as the ink passes through.
A film covering the opening of the foreign matter removing chamber and
A reinforcing member fixed to the film on the foreign matter removing chamber side of the film,
The inkjet printer according to any one of claims 1 to 9. The inkjet printer according to claim 10, wherein welding marks are formed between the film and the reinforcing member. The main body provided with the foreign matter removal chamber is provided.
The inkjet printer according to claim 10 or 11, wherein other welding marks are formed between the film and the main body. The inkjet printer according to any one of claims 1 to 12, further comprising a relief valve provided in the return flow path so that the return flow path can be opened and closed. The relief valve opens the return flow path at the first pressure or higher in the first state, and is higher than the first pressure in the second state different from the first state. The inkjet printer according to claim 13, which is configured to open the return flow path when the pressure is higher than the pressure. The relief valve is
The valve inflow path through which ink flows and
A valve inlet to which the valve inflow path is connected, a valve ink chamber in which a valve outlet is formed, and a valve ink chamber.
A valve outflow path connected to the valve outflow port and through which ink flows out,
A valve body that can open and close the valve outlet,
A first spring that applies an elastic force to the valve body in the direction toward the valve outlet,
A valve rod that comes into contact with the valve body and opens and closes the valve body with respect to the valve outlet.
Solenoid and
With
The solenoid is
Solenoid body and
A shaft core that can be movably inserted into the solenoid body with respect to the solenoid body and can come into contact with the valve rod.
Have,
A second spring that applies an elastic force to the shaft core in a direction away from the solenoid body is provided.
When the solenoid is ON, the position of the shaft core is fixed at a position where the valve rod and the shaft core are separated from each other.
The inkjet printer according to claim 14, wherein when the solenoid is OFF, the shaft core is configured to be movable with respect to the solenoid main body in a state where the valve rod and the shaft core are in contact with each other. The relief valve is
The valve inflow path through which ink flows and
A valve inlet to which the valve inflow path is connected, a valve ink chamber in which a valve outlet is formed, and a valve ink chamber.
A valve outflow path connected to the valve outflow port and through which ink flows out,
A valve body that can open and close the valve outlet,
A first spring that applies an elastic force to the valve body in the direction toward the valve outlet,
A valve rod that comes into contact with the valve body and opens and closes the valve body with respect to the valve outlet.
Solenoid and
With
The solenoid is
Solenoid body and
A shaft core that can be movably inserted into the solenoid body with respect to the solenoid body and can come into contact with the valve rod.
Have,
A second spring that applies an elastic force to the shaft core in a direction approaching the solenoid body is provided.
When the solenoid is OFF, the position of the shaft core is fixed at a position where the valve rod and the shaft core are separated from each other.
The inkjet printer according to claim 14, wherein when the solenoid is ON, the shaft core is configured to be movable with respect to the solenoid main body in a state where the valve rod and the shaft core are in contact with each other. The first state is a state in which the position of the shaft core is fixed at a position where the valve rod and the shaft core are separated from each other.
The inkjet printer according to claim 15 or 16, wherein the second state is a state in which the valve rod and the shaft core are in contact with each other and the shaft core is movable with respect to the solenoid body. The first pressure is 30 kPa to 50 kPa.
The inkjet printer according to any one of claims 14 to 17, wherein the second pressure is 130 kPa to 170 kPa. It is provided with a pressure release valve mechanism that is connected to the other end of the third forward flow path and communicates with the nozzle.
The pressure release valve mechanism is
A second inflow path whose one end is connected to the other end of the third forward flow path,
A pressure-open ink chamber in which a second inflow port to which the other end of the second inflow path is connected is formed and a second inflow port is formed, and a pressurized open ink chamber.
A second outflow path, one end of which is connected to the second outlet and the other end of which communicates with the nozzle.
When the pressure in the second inflow path is higher than the first pressure and lower than the third pressure lower than the second pressure, the second inflow port or the second outflow port is closed and the second inflow A second valve body that opens the second inlet or the second outlet when the road pressure is equal to or higher than the third pressure.
The inkjet printer according to any one of claims 13 to 18. In the pressure release valve mechanism, when the ink head is cleaned, the second valve body opens the second inflow port, and when the ink head is not cleaned, the second valve body is the second valve body. 2. The inkjet printer according to claim 19, which is configured to close the inlet. It is provided with a pressure release valve mechanism that is connected to the other end of the third forward flow path and communicates with the nozzle.
The pressure release valve mechanism is
A second inflow path whose one end is connected to the other end of the third forward flow path,
A pressure-open ink chamber in which a second inflow port to which the other end of the second inflow path is connected is formed and a second inflow port is formed, and a pressurized open ink chamber.
A second outflow path, one end of which is connected to the second outlet and the other end of which communicates with the nozzle.
A second valve body that opens the second inlet or the second outlet,
Have,
The second valve body opens the second inlet or the second outlet when the ink head is cleaned, and when the ink head is not cleaned, the second inlet or the second inlet is used. The inkjet printer according to any one of claims 13 to 18, which is configured to close the outlet. The inkjet printer according to any one of claims 19 to 21, further comprising one main body provided with the negative pressure release valve mechanism and the pressure release valve mechanism. The inkjet printer according to claim 22, wherein the central axis of the first valve body of the negative pressure release valve mechanism and the central axis of the second valve body of the pressure release valve mechanism are substantially parallel to each other. The inkjet according to claim 22 or 23, wherein the central axis of the first valve body of the negative pressure release valve mechanism and the central axis of the second valve body of the pressure release valve mechanism are substantially horizontal. Printer. The inkjet printer according to any one of claims 22 to 24, wherein the negative pressure release valve mechanism and the pressure release valve mechanism are arranged one above the other. The invention according to any one of claims 22 to 25, wherein at least a part of the second negative pressure release ink chamber and at least a part of the pressure release ink chamber are formed in the main body. Inkjet printer. The negative pressure release valve mechanism has a first valve seat with which the first valve body comes into contact when the first valve body closes the communication port.
The pressure release valve mechanism has a second valve seat with which the second valve body comes into contact when the second valve body closes the second inlet or the second outlet.
The first inflow port is arranged on one side of the first valve seat, and the first outlet is arranged on the other side of the first valve seat.
Any of claims 22 to 26, wherein the second inflow port is arranged on the one side of the second valve seat, and the second outlet is arranged on the other side of the second valve seat. The inkjet printer described in one. The ink head has a nozzle surface on which the nozzle is formed.
A cap that can be attached to the nozzle surface so as to cover the nozzle,
With the suction pump connected to the cap,
The inkjet printer according to any one of claims 19 to 27. Equipped with a control device
The control device includes a cleaning suction pump control unit that drives the suction pump and stops the liquid feed pump with the cap attached to the nozzle surface when cleaning the ink head. The inkjet printer according to claim 28. Equipped with a control device
The control device includes a cleaning liquid feed pump control unit that drives the liquid feed pump and stops the suction pump with the cap attached to the nozzle surface when cleaning the ink head. The inkjet printer according to claim 28 or 29. Equipped with a control device
The control device is
When cleaning the ink head, a first cleaning pump control unit that drives the suction pump with the cap attached to the nozzle surface, and
After the suction pump is driven by the first cleaning pump control unit, the second cleaning pump control unit that drives the liquid feed pump and the second cleaning pump control unit
The inkjet printer according to any one of claims 28 to 30, wherein the inkjet printer comprises the above. A wiper mechanism having a wiper that wipes the nozzle surface,
Control device and
With
The control device wipes the nozzle surface with the wiper after driving the liquid feed pump or while driving the liquid feed pump while the pressure release valve mechanism is open. The inkjet printer according to any one of claims 19 to 31, further comprising a wiping control unit for controlling the wiper mechanism. Equipped with a control device
The control device is
In a state where the pressure release valve mechanism is closed, the relief valve is closed, and the first circulation control unit that drives the liquid feed pump and the first circulation control unit.
After the control by the first circulation control unit, the second circulation control unit that opens the relief valve and
The inkjet printer according to any one of claims 19 to 32. Equipped with a control device
The control device is
A printing valve control unit that controls the relief valve so that the relief valve is in the first state during printing.
A cleaning valve control unit that controls the relief valve so that the relief valve is in the second state during cleaning.
The inkjet printer according to any one of claims 14 to 18.

Images