Patent Publication Number: US-10773526-B2

Title: Liquid ejecting apparatus and maintenance method of liquid ejecting apparatus

Description:
The present application is based on, and claims priority from JP Application Ser. No. 2018-179824, filed Sept. 26, 2018, the disclosure of which is hereby incorporated by reference herein in its entirety. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to, for example, a liquid ejecting apparatus including a pressure adjustment section that adjusts a supply pressure of a liquid supplied to a liquid ejecting head, and a method of maintaining a liquid ejecting apparatus. 
     2. Related Art 
     A liquid ejecting head is configured to receive supply of a liquid from a liquid supply member and to eject the liquid from a nozzle by driving an actuator such as a piezoelectric element. The liquid ejecting apparatus provided with the liquid ejecting head includes a pressure adjustment mechanism that includes a liquid chamber having an introduction port through which a liquid from the liquid supply member flows in and an outlet communicating with a liquid ejecting head side in an intermediate of a flow path from the liquid supply member to the nozzle of the liquid ejecting head, an air chamber into which air is capable of flowing, a flexible member that separates the liquid chamber from the air chamber. The pressure adjustment mechanism pressurizes the air chamber by sending air into the air chamber and deforms the flexible member toward the liquid chamber to send out the liquid in the liquid chamber from the outlet to the liquid ejecting head side (see, for example, JP-A-2015-189201). According to the configuration of JP-A-2015-189201, it is possible to perform pressure cleaning, which is a maintenance operation for forcibly discharging the liquid or air bubbles from the nozzle of the liquid ejecting head, using the pressure adjustment section. 
     In the pressure adjustment section of JP-A-2015-189201, a total amount (hereinafter simply referred to as a discharge amount) of the liquid discharged from each nozzle at the time of the pressure cleaning is determined in accordance with a deformation amount of the flexible member, but it is difficult to adjust the deformation amount of the flexible member. Therefore, for example, it has been difficult to perform a plurality of pressure cleanings with different discharge amounts of the liquid with a simple configuration without using a pressure sensor or the like. 
     SUMMARY 
     According to an aspect of the present disclosure, there is provided a liquid ejecting apparatus including: a liquid ejecting unit ejecting a liquid from a nozzle; and a pressure adjustment section adjusting a pressure of the liquid to be supplied to the liquid ejecting unit, in which the pressure adjustment section includes a liquid chamber communicating with the liquid ejecting unit and storing the liquid to be supplied to the liquid ejecting unit, a fluid chamber into which a fluid is capable of flowing, a flexible member that includes an elastically deformable film and a first seal portion provided in the film, the flexible member being interposed between the liquid chamber and the fluid chamber to separate the liquid chamber and the fluid chamber from each other, and a pressurizing section that supplies the fluid to the fluid chamber and pressurizes the flexible member toward the liquid chamber with the fluid, the fluid chamber includes a first contact portion configured to come into contact with the first seal portion, and the fluid chamber is configured such that the first contact portion and the first seal portion come into contact with each other so as to be partitioned into a first fluid chamber having an introduction port through which the fluid flows in and a second fluid chamber, and the pressurizing section converts, by supplying the fluid to the fluid chamber, a state of the fluid chamber into a first state in which the first contact portion and the first seal portion are in contact with each other, or a second state in which the contact between the first contact portion and the first seal portion is released so that the first fluid chamber and the second fluid chamber communicate with each other. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view for explaining a configuration of an embodiment of a liquid ejecting apparatus. 
         FIG. 2  is a sectional view for explaining a configuration of an embodiment of a liquid ejecting head. 
         FIG. 3  is a sectional view for explaining a configuration of an embodiment of the liquid ejecting unit. 
         FIG. 4  is a sectional view for explaining a configuration of a pressure adjustment section. 
         FIG. 5  is a plan view for explaining a configuration of a fluid chamber side in the pressure adjustment section. 
         FIG. 6  is a plan view for explaining a configuration of a liquid chamber side in the pressure adjustment section. 
         FIG. 7  is a sectional view of the pressure adjustment section illustrating a state in which first pressure cleaning is performed. 
         FIG. 8  is a sectional view of the pressure adjustment section illustrating a state in which second pressure cleaning is performed. 
         FIG. 9  is a graph for explaining a relationship between a driving time of an air pump and a discharge amount of ink in pressure cleaning. 
         FIG. 10  is a plan view for explaining a configuration of a fluid chamber side in a pressure adjustment section in a second embodiment. 
         FIG. 11  is a plan view for explaining a configuration of a liquid chamber side in the pressure adjustment section according to the second embodiment. 
         FIG. 12  is a sectional view of a pressure adjustment section illustrating a state in which first pressure cleaning is performed in a third embodiment. 
         FIG. 13  is a sectional view of a pressure adjustment section illustrating a state in which second pressure cleaning is performed in the third embodiment. 
         FIG. 14  is a sectional view of a pressure adjustment section illustrating a state in which third pressure cleaning is performed in the third embodiment. 
         FIG. 15  is a sectional view of a pressure adjustment section illustrating a state in which first pressure cleaning is performed in a fourth embodiment. 
         FIG. 16  is a sectional view of the pressure adjustment section illustrating a state in which second pressure cleaning is performed in the fourth embodiment. 
         FIG. 17  is a sectional view of the pressure adjustment section illustrating a state in which third pressure cleaning is performed in the fourth embodiment. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     Hereinafter, embodiments for executing the present disclosure will be described with reference to the attached drawings. In the embodiments described below, various limitations are given as preferable specific examples of the present disclosure, but the scope of the present disclosure is not limited to these embodiments unless specifically stated in the following description to limit the present disclosure. Further, the following description will be made by taking an ink jet printer (hereinafter, printer)  1  as a liquid ejecting apparatus equipped with an ink jet recording head (hereinafter, recording head)  10  which is a type of the liquid ejecting head. 
       FIG. 1  is a plan view illustrating a configuration of an embodiment of the printer  1 . The printer  1  in the present embodiment is an apparatus that ejects liquid ink (a type of the liquid in the present disclosure) from the recording head  10  onto a surface of a recording medium such as a recording sheet, cloth, or a resin film to record an image, a text, or the like. The printer  1  includes a frame  2  and a platen  3  disposed in the frame  2 , and the recording medium is transported onto the platen  3  by a transport mechanism (not illustrated). Further, in the frame  2 , a guide rod  4  is provided in parallel with the platen  3 , and a carriage  5  accommodating the recording head  10  is slidably supported by the guide rod  4 . The carriage  5  is configured to reciprocate in a main scanning direction orthogonal to a paper feeding direction along the guide rod  4  by a carriage moving mechanism. The carriage moving mechanism includes a pulse motor  6 , a drive pulley  7  which is rotated by driving of the pulse motor  6 , an idle pulley  8  provided on an opposite side to the drive pulley  7  in the frame  2 , and a timing belt  9  provided between the drive pulley  7  and the idle pulley  8 . The printer  1  in the embodiment ejects ink from a nozzle  30  (see  FIG. 3  or the like) of the recording head  10  while causing the carriage  5  to reciprocate relative to the recording medium, and performs a recording operation, that is, a liquid ejecting operation. 
     A cartridge holder  14  for detachably mounting an ink cartridge  13  which is a type of a liquid supply member is provided on one side of the frame  2 . The ink cartridge  13  is coupled to an air pump  16  via an air tube  15 , and air from the air pump  16  is supplied into each ink cartridge  13 . An ink pack (not illustrated) disposed in the ink cartridge  13  is pressurized by the pressurized air, so that the ink in the ink pack is supplied to the recording head  10  side through the ink supply tube  17 . The air pump  16  is configured to be capable of selectively executing a pressurizing operation that feeds air into a flow path or a space coupled to the air pump  16 , and a depressurizing operation that sucks the air from the flow path or the like in accordance with an instruction from the control section (not illustrated) of the printer  1 . The air pump  16  is configured to be capable of switching the coupling to a capping mechanism  11  described later and gas flow paths  59  and  64  of a flow path unit  21  described later, in addition to the ink cartridge  13 . That is, the air pump  16  functions as a pressurizing section that pressurizes a fluid chamber  58  of a pressure adjustment section  54  through the gas flow path  59  of the flow path unit  21 . 
     The ink sent from the ink supply tube  17  from the ink cartridge  13  is first introduced into the flow path unit  21  of the recording head  10  mounted on the carriage  5 . The ink introduced into the flow path unit  21  is supplied to an ink flow path inside the liquid ejecting unit  23  via a self-sealing unit  22 , a flow path opening/closing section  55 , and the pressure adjustment section  54 , which are described later. In addition, as the liquid supply member, it is not limited to the illustrated one, and various structures such as a cartridge type, a pack type, a tank type can be adopted. The ink supply tube  17  is, for example, a flexible hollow member made of a synthetic resin, and an ink flow path corresponding to each ink cartridge  13  is formed inside the ink supply tube  17 . In addition, an flexible flat cable (FFC)  18  for transmitting a drive signal or the like from the control section (not illustrated) on a main body side of the printer  1  to the recording head  10  side is wired between the main body side of the printer  1  and the recording head  10  side. 
     The capping mechanism  11  for sealing a nozzle formation surface of the recording head  10  and a wiping mechanism  12  for wiping the nozzle formation surface of the recording head  10  are disposed in parallel at a home position provided on one side (cartridge holder  14  side) in a movement range of the recording head  10  inside the frame  2 . The capping mechanism  11  seals a surface on which the nozzle  30  of the recording head  10  in a standby state at the home position is formed, and suppresses the evaporation of a solvent of the ink from the nozzle  30 . In addition, the capping mechanism  11  functions as a receptacle for the ink or the like discharged from the nozzle  30  of the recording head  10  in pressure cleaning which is a maintenance operation described later. The wiping mechanism  12  is a mechanism that performs a wiping operation that wipes off the ink or the like attached to the nozzle forming surface by relatively moving in a state of being in contact with the nozzle forming surface. 
       FIG. 2  is a sectional view for explaining a configuration of the recording head  10 . The recording head  10  in the present embodiment is formed as one unit combining the flow path unit  21  in which self-sealing units  22   a  and  22   b  to which two colors of ink are supplied and four types of flow paths corresponding to respective colors corresponding to four colors of ink, for example, black (K), cyan (C), magenta (M), and yellow (Y), and the liquid ejecting unit  23  (a type of liquid ejecting unit in the present disclosure). 
       FIG. 3  is a sectional view for explaining an example of the configuration of the liquid ejecting unit  23 . The liquid ejecting unit  23  in the present embodiment is formed by stacking a plurality of constituent members such as a nozzle plate  24 , a communication plate  25 , an actuator substrate  26 , a compliance substrate  27 , and a case  28 , and joining them with an adhesive or the like. 
     The actuator substrate  26  in the present embodiment includes a plurality of pressure chambers  33  respectively communicating with a plurality of nozzles  30  formed on the nozzle plate  24 , and a plurality of piezoelectric elements  31  which are actuators that generate pressure fluctuation in the ink in each pressure chamber  33 . A vibration plate  36  is provided between the pressure chamber  33  and the piezoelectric element  31 , and an upper opening of the pressure chamber  33  is sealed by the vibration plate  36  to partition a part of the pressure chamber  33 . The vibration plate  36  is made of, for example, an elastic film formed of silicon dioxide (SiO 2 ) and an insulator film formed of zirconium oxide (ZrO 2 ) formed on the elastic film. The piezoelectric elements  31  are respectively stacked in regions corresponding to the respective pressure chambers  33  on the vibration plate  36 . The piezoelectric element  31  in the present embodiment is, for example, formed by sequentially stacking a lower electrode layer, a piezoelectric layer, and an upper electrode layer (all are not illustrated) on the vibration plate  36 . The piezoelectric element  31  configured in this manner is bent and deformed when an electric field corresponding to a potential difference of both electrodes between the lower electrode layer and the upper electrode layer is applied. 
     The communication plate  25  having a larger area than that of the actuator substrate  26  in a plan view seen from the substrate stacking direction is joined to the lower surface of the actuator substrate  26 . In the communication plate  25  in the present embodiment, a nozzle communication port  34  causing the pressure chamber  33  to communicate with the nozzle  30 , a common liquid chamber  37  provided in common to respective pressure chambers  33 , and an individual communication port  35  causing the common liquid chamber  37  to communicate with the pressure chamber  33  are formed. The common liquid chamber  37  is an empty portion extending in a direction in which the nozzles  30  are provided in parallel. In the present embodiment, two common liquid chambers  37  are formed corresponding to each row of two nozzles  30  provided in the nozzle plate  24 . A plurality of individual communication ports  35  are formed corresponding to the respective pressure chambers  33  in a nozzle row direction. The individual communication port  35  communicates with an end portion of the pressure chamber  33  on a side opposite to a portion communicating with the nozzle communication port  34 . 
     The nozzle plate  24  in which the plurality of nozzles  30  are formed is joined to a substantially central portion of a lower surface of the communication plate  25 . The nozzle plate  24  in the present embodiment is a plate member having an outer shape smaller than the communication plate  25  in a plan view. The nozzle plate  24  is located at a position deviated from an opening of the common liquid chamber  37  on the lower surface of the communication plate  25 , and is joined to a region where the nozzle communication port  34  is open in a state in which the nozzle communication ports  34  and the plurality of nozzles  30  communicate with each other. In the nozzle plate  24  in the present embodiment, a total of two nozzle rows in which the plurality of nozzles  30  are provided in parallel is formed. Further, the compliance substrate  27  is joined at a position deviated from the nozzle plate  24  on the lower surface of the communication plate  25 . The compliance substrate  27  seals the opening of the common liquid chamber  37  on the lower surface of the communication plate  25  in a state of being positioned and joined to the lower surface of the communication plate  25 . The compliance substrate  27  has a function of alleviating pressure fluctuation in the ink flow path, particularly in the common liquid chamber  37 . 
     The actuator substrate  26  and the communication plate  25  are fixed to the case  28 . In the inside of the case  28 , introduction liquid chambers  42  communicating with the common liquid chambers  37  of the communication plate  25  are formed on both sides with the actuator substrate  26  interposed therebetween. Further, an inlet  43  communicating with each introduction liquid chamber  42  is open on an upper surface of the case  28 . The inlet  43  communicates with a third flow path  68  of the flow path unit  21  described later. Therefore, the ink sent from the flow path unit  21  is introduced into the inlet  43 , the introduction liquid chamber  42 , and the common liquid chamber  37 , and is supplied from the common liquid chamber  37  to each pressure chambers  33  through the individual communication ports  35 . In the liquid ejecting unit  23  configured as described above, the piezoelectric element  31  is driven in a state in which the inside of the flow path from the introduction liquid chamber  42  to the nozzle  30  through the common liquid chamber  37  and the pressure chamber  33  is filled with ink. Therefore, pressure fluctuation occurs in the ink in the pressure chamber  33 , and the ink is ejected from a predetermined nozzle  30  by the pressure fluctuation (in other words, pressure vibration). The recording head  10  is not limited to the illustrated configuration, and various known configurations can be adopted. For example, a liquid ejecting head configured to circulate ink with the liquid supply member can be adopted. Also, it is also possible to adopt a so-called line type liquid ejecting head which has a unit head group in which a plurality of unit heads are arranged in a direction intersecting a transport direction of the recording medium, and in which an entire length of the nozzle group formed by the unit head group corresponds to a maximum recording width of the recording medium. 
     The self-sealing unit  22  is a unit that receives the ink, which is sent from the ink cartridge  13  side through the ink supply tube  17 , from the supply port  44  and regulates the supply of the ink to the liquid ejecting unit  23  side of the ink. In the self-sealing unit  22 , when a negative pressure in the pressure adjustment chamber (not illustrated) exceeds a predetermined value as the ink is ejected from the liquid ejecting unit  23 , a closed liquid flow path is opened. Therefore, the ink is supplied to the liquid ejecting unit  23  side. 
     The flow path unit  21  includes a first flow path substrate  45 , a second flow path substrate  46 , a third flow path substrate  47 , a fourth flow path substrate  48 , a fifth flow path substrate  49 , a flexible member  51 , and a flow path opening/closing film  52  which are stacked. Further, the flow path unit  21  has the pressure adjustment section  54  and a flow path opening/closing section  55 . The pressure adjustment section  54  is provided in a middle of the liquid flow path between the self-sealing unit  22  and the liquid ejecting unit  23 , and has a function of adjusting the pressure in the liquid flow path by changing a volume of the liquid flow path. In addition, the flow path opening/closing section  55  is located in the middle of the liquid flow path between the self-sealing unit  22  and the pressure adjustment section  54 , and has a function of opening and closing the liquid flow path. 
     In the flow path unit  21 , a liquid chamber  57  (a type of the liquid chamber in the present disclosure) is formed on the lower surface of the fourth flow path substrate  48  on the fifth flow path substrate  49  side. A fluid chamber  58  (a type of the fluid chamber in the present disclosure) corresponding to the liquid chamber  57  is formed on the upper surface of the fifth flow path substrate  49  on the fourth flow path substrate  48  side. A flexible member  51  (a type of the flexible member in the present disclosure) formed of an elastic material such as rubber is interposed between the liquid chamber  57  and the fluid chamber  58 . Therefore, the liquid chamber  57  and the fluid chamber  58  are partitioned, that is, separated by the flexible member  51 . As described later, the volume of the liquid chamber  57  can be changed by the deformation of the flexible member  51  in a stacking direction of the flow path substrate. The flexible member  51  functions as a pressure adjustment film. The liquid chamber  57  in the present embodiment can be said to be an ink chamber. Similarly, the fluid chamber  58  in the present embodiment can be said to be a gas chamber. 
     The gas flow path  59  opened on the upper surface of the first flow path substrate  45  penetrates the flow path substrates  45 ,  46 ,  47 , and  48  to reach the lower surface of the fifth flow path substrate  49 , and further, communicates with the fluid chamber  58  from the lower surface side through a vent  59   a  (see  FIG. 4  or the like). The gas supply port  60  provided on the upper surface of the first flow path substrate  45  and the fluid chamber  58  communicate with each other by the gas flow path  59 . Therefore, a deformation amount of the flexible member  51  can be adjusted by adjusting an amount of gas (that is, air or the like) which is a type of the fluid supplied from the air pump  16  through the gas supply port  60 . As described later, the liquid chamber  57  communicates with the third flow path  68 , which is an ink flow path, through the ink outlet  68   a  (see  FIG. 4 ). That is, the liquid chamber  57 , the fluid chamber  58 , and the flexible member  51  form the pressure adjustment section  54  that adjusts the pressure in the ink flow path. Such a pressure adjustment section  54  is provided for each type of ink (for example, for each color of ink). Details of the pressure adjustment section  54  will be described later. 
     A first recess portion  62  is formed on the upper surface of the third flow path substrate  47 , and a second recess portion  63  corresponding to the first recess portion  62  is formed on the lower surface of the second flow path substrate  46 . The flow path opening/closing film  52  formed of an elastic material similar to the flexible member  51  is interposed between the first recess portion  62  and the second recess portion  63 . Therefore, the first recess portion  62  and the second recess portion  63  are partitioned by the flow path opening/closing film  52 . The flow path can be closed or opened by the deformation of the flow path opening/closing film  52  in the substrate stacking direction. That is, the flow path opening/closing film  52  is deformed so as to bend toward the first recess portion  62 , and the flow path is closed by coming into contact with and sealing a bottom surface of the first recess portion  62 . Further, the flow path opening/closing film  52  is deformed so as to bend toward the second recess portion  63 , and the seal between the flow path opening/closing film  52  and the bottom surface of the first recess portion  62  is released, so that the flow path is opened. The gas flow path  64  opened on the upper surface of the first flow path substrate  45  penetrates the first flow path substrate  45  to reach the upper surface of the second flow path substrate  46 . A horizontal flow path  64   a  is formed on the upper surface of the second flow path substrate  46 , and the gas flow path  64  communicates with the second recess portion  63  via the horizontal flow path  64   a . Therefore, the gas flow path  64  from the gas supply port  65  provided on the upper surface of the first flow path substrate  45  to the second recess portion  63  is communicated. Therefore, when the gas is supplied from the air pump  16  through the gas supply port  65 , the flow path opening/closing film  52  can be deformed to open/close the flow path. The first recess portion  62  communicates with the first flow path  66  which is an ink flow path. That is, the first recess portion  62 , the second recess portion  63 , and the flow path opening/closing film  52  form the flow path opening/closing section  55  that opens and closes the ink flow path. Similar to the pressure adjustment section  54 , such a flow path opening/closing section  55  is provided for each ink type (for example, for each ink color). 
     In the flow path unit  21 , a first flow path  66 , a second flow path  67 , and a third flow path  68  are formed as ink flow paths. The first flow path  66  is an ink flow path for introducing the ink supplied from one of the self-sealing units  22  into the first recess portion  62 . The second flow path  67  is an ink flow path communicating with the first recess portion  62  and the liquid chamber  57 . The third flow path  68  is an ink flow path communicating with the liquid chamber  57  and the inlet  43  of the liquid ejecting unit  23 . That is, the third flow path  68  liquid-tightly communicates with the inlet  43  of the liquid ejecting unit  23  on the lower surface of the fifth flow path substrate  49 . 
     In such a flow path unit  21 , the flow path opening/closing section  55  is disposed between the first flow path  66  and the second flow path  67  in the ink flow path from the self-sealing unit  22  to the liquid ejecting unit  23 . The pressure adjustment section  54  is disposed between the second flow path  67  and the third flow path  68 . The flow path unit  21  adjusts the pressure of the ink in the ink flow path with the pressure adjustment section  54 , and opens and closes a space between the pressure adjustment section  54  and the self-sealing unit  22  with the flow path opening/closing section  55 . In addition, the pressure adjustment section  54  causes the gas from the air pump  16  to flow into the fluid chamber  58  and deforms the flexible member  51  so as to bend to the liquid chamber  57  side. Therefore, it is possible to perform pressure cleaning in which the ink in the liquid chamber  57  is extruded to be sent to the liquid ejecting unit  23  side and the ink, bubbles, or the like in the liquid ejecting unit  23  is forcibly discharged from each nozzles  30  of the liquid ejecting unit  23 . In this case, prior to pressurization by the pressure adjustment section  54 , the flow path is closed by the flow path opening/closing section  55 . 
     Here, in order to perform the pressure cleaning more efficiently, that is, in order to suppress waste of an amount of ink consumed in the pressure cleaning, it is desirable that the cleaning operation of a plurality of patterns having different discharge amounts of the ink discharged from the recording head  10  can be selectively performed by the pressure cleaning according to the state and purpose of the printer  1  and the recording head  10 . For example, in the cleaning operation for the purpose of removing foreign matter such as paper dust adhering to the vicinity of the nozzle  30  on the nozzle formation surface, the consumption amount of the ink can be reduced by executing the cleaning operation with a relatively small discharge amount. Further, for example, in the cleaning operation for the purpose of discharging air bubbles, thickened ink, or the like at a position relatively close to the nozzles  30  in the flow path inside the liquid ejecting unit  23 , it is necessary to further increase the discharge amount. Furthermore, for example, in the cleaning operation for the purpose of discharging air bubbles or the like in the flow path from the pressure adjustment section  54  to the liquid ejecting unit  23 , it is necessary to further increase the discharge amount. Therefore, when it is only possible to execute pressure cleaning with a constant discharge amount of ink, the discharge amount may be excessive or insufficient depending on the state and purpose of the printer  1  and the recording head  10 , which is not efficient. 
     Therefore, for example, it is also conceivable to control the discharge amount of the ink in the pressure cleaning by detecting the deformation amount of the flexible member  51  in the liquid chamber  57  in the pressure adjustment section  54  by a photosensor. However, the photosensor can only detect a specific deformation amount, and it is necessary to provide a plurality of photosensors in order to detect a plurality of deformation amounts, resulting in a problem that the configuration is complicated and the cost is also increased. Similarly, it is also conceivable to control the discharge amount of ink at the time of the pressure cleaning by adjusting a pressure inside the fluid chamber  58  using a pressure sensor or the like capable of detecting the pressure inside the fluid chamber  58 . However, provision of a pressure sensor capable of always detecting the pressure inside the fluid chamber  58  leads to an increase in cost. 
     Further, for example, it is also conceivable to adjust the discharge amount at the time of the pressure cleaning by controlling a driving time of the air pump  16  for feeding the gas into the fluid chamber  58 , that is, a driving time of the pressurizing section without providing various sensors as described above. However, when the discharge amount is changed by the driving time of the pressurizing section in the configuration or the related art, there is a problem that it is easily affected by dimensional error, temperature, or the like of the structure, and an error easily occurs as compared with a case where the discharge amount is adjusted using a sensor. In view of such a problem, in the printer  1  according to the present disclosure, a plurality of pressure cleanings with different discharge amounts of the ink can be performed more accurately by controlling the driving time of the air pump  16 , that is, the driving time of the pressurizing section. Hereinafter, this point will be described. 
       FIG. 4  is a sectional view for explaining a configuration of the pressure adjustment section  54 ,  FIG. 5  is a plan view for explaining a configuration of the fluid chamber  58  side (that is, a portion corresponding to the fluid chamber  58  on the upper surface of the fifth flow path substrate) in the pressure adjustment section  54 , and  FIG. 6  is a plan view for explaining a configuration of the liquid chamber  57  side (that is, a portion corresponding to the liquid chamber  57  on the lower surface of the fourth flow path substrate) in the pressure adjustment section  54 . A normal state in which the pressure cleaning is not performed, a state in which the pressure inside the fluid chamber  58  and the pressure inside the liquid chamber  57  are balanced, or a state in which the pressure inside the fluid chamber  58  is lower than that of the state is illustrated in  FIG. 4 . 
     In the present embodiment, the fluid chamber  58  formed in the fifth flow path substrate  49  is a recess portion having a circular shape in a plan view as viewed in the stacking direction of the flow path substrate, and is open to the liquid chamber  57  side of the fourth flow path substrate  48 . The opening of the fluid chamber  58  is sealed by the flexible member  51 . The vent  59   a  (a type of the introduction port in the present disclosure) communicating with the gas flow path  59  is open at a center portion of the bottom of the fluid chamber  58 . Therefore, the inside of the fluid chamber  58  can be depressurized or pressurized by the gas flowing out or flowing into the fluid chamber  58  through the gas flow path  59  and the vent  59   a  by driving the air pump  16 . Therefore, the flexible member  51  sealing the opening of the fluid chamber  58  is deformed to bend in the stacking direction of the flow path substrate. Although the fluid chamber  58  in the present embodiment is configured as a space into which the gas that is a type of the fluid, that is, air flows, it can be a fluid chamber into which a liquid as a type of the fluid flows. That is, a configuration can be adopted in which the flexible member is pressurized by a fluid such as a liquid flowing into the fluid chamber. 
     A rib-like support member  77  for supporting the flexible member  51  is erected on the bottom surface of the fluid chamber  58  toward the liquid chamber  57  in a state of surrounding a periphery of the vent  59   a . The support member  77  comes into contact with the seal portion  76  of the flexible member  51  described later to partition the fluid chamber  58  into a first fluid chamber  70  (corresponding to the first fluid chamber in the present disclosure) having the vent  59   a  and a second fluid chamber  71  (corresponding to the second fluid chamber in the present disclosure). The support member  77  in the present embodiment has an annular shape centering on the vent  59   a  in a plan view. A top surface (surface facing the liquid chamber  57 ) of the support member  77  functions as a first contact portion capable of coming into contact with the seal portion  76  of the flexible member  51 . 
     The liquid chamber  57  in the present embodiment is configured by concentrically forming a first liquid chamber  72  and a second liquid chamber  73 , which are cylindrical recess portions having different depths and inner diameters. Specifically, the second liquid chamber  73  is a liquid chamber of which the inner diameter is substantially equal to an opening diameter of the fluid chamber  58  and of which the depth is set to be relatively shallow. On the other hand, the first liquid chamber  72  is a liquid chamber of which the inner diameter is set smaller than that the second liquid chamber  73  and of which the depth is set deeper than that of the second liquid chamber  73 . Therefore, a step is generated between the first liquid chamber  72  and the second liquid chamber  73 , and the stepped portion functions as a ceiling surface  73   a  of the second liquid chamber  73 . A regulation member  78  is provided on the ceiling surface  73   a  of the second liquid chamber  73  so as to protrude toward the fluid chamber  58 . 
     The regulation member  78  in the present embodiment has an annular shape in a plan view corresponding to the support member  77  of the fluid chamber  58 , and the seal portion  76  of the flexible member  51  is pinched between a lower surface of the regulation member  78  on the support member  77  side and a top surface of the support member  77 . The regulation member  78  is provided on the liquid chamber  57  side to regulate the deformation of the seal portion  76  of the flexible member  51  to the liquid chamber  57  side. That is, the regulation member  78  functions as a bias member that biases the seal portion  76  of the flexible member  51  toward the support member  77 . A communication portion  74  penetrating in a wall thickness direction is formed on the ceiling surface  73   a  side of the regulation member  78 , and the first liquid chamber  72  and the second liquid chamber  73  communicate with each other through the communication portion  74 . A set of the support member  77 , the seal portion  76 , and the regulation member  78  in the present embodiment constitutes a partition structure  69  that partitions the fluid chamber  58  into the first fluid chamber  70  and the second fluid chamber  71 . Although the regulation member  78  in the present embodiment is configured to be supported by the ceiling surface  73   a  of the second liquid chamber  73 , the present disclosure is not limited thereto. For example it is also possible to adopt a configuration supported by a support member in a form of a beam from a side wall of the liquid chamber  57 . 
     An ink inlet  67   a  communicating with the second flow path  67  and an ink outlet  68   a  communicating with the third flow path  68  are open on the ceiling surface  72   a  of the first liquid chamber  72 . In a state in which the flow path opening/closing section  55  is opened, the ink from the self-sealing unit  22  side is introduced into the liquid chamber  57  through the ink inlet  67   a  via the flow path opening/closing section  55 . Further, in a state in which the flow path opening/closing section  55  is closed, when air is fed into the fluid chamber  58  by driving of the air pump  16  so that the flexible member  51  is pressurized toward the liquid chamber  57  by the air and is deformed to bend, the ink in the liquid chamber  57  is drawn out from the ink outlet  68   a  to the liquid ejecting unit  23  side through the third flow path  68 . 
     As described above, the flexible member  51  is a flexible film-like member made of an elastic material. In the flexible member  51  of the present embodiment, a portion being in contact with the support member  77  is the seal portion  76  (a type of the first seal portion in the present disclosure), and the other portion is the film  75  (a type of the film in the present disclosure). A thickness of the seal portion  76  is set to be equal to or greater than a distance (in other words, an interval) between the lower surface (regulation surface) of the regulation member  78  on the support member  77  side and the top surface of the support member  77  in a state in which the seal portion  76  does not come into contact with any of the support member  77  and the regulation member  78 . Therefore, in a first state described below, the seal portion  76  is in a crushed state between the lower surface (regulation surface) of the regulation member  78  on the support member  77  side and the top surface of the support member  77 , and adhesion is increased, so that the first fluid chamber  70  and the second fluid chamber  71  can be more reliably shut off. 
     In the pressure adjustment section  54  having such a configuration, it is configured to be convertible to the first state in which the support member  77  of the fluid chamber  58  and the seal portion  76  of the flexible member  51  come into contact with each other to be sealed, and the first fluid chamber  70  and the second fluid chamber  71  do not communicate with each other in the fluid chamber  58 , and a state in which the support member  77  and the seal portion  76  come into contact with each other, that is, the second state in which the sealed state is released, and the first fluid chamber  70  and the second fluid chamber  71  communicate with each other. Therefore, as described below, it is possible to be switched to the first state in which the ink in the liquid chamber  57  is pressurized only by the film  75  of the portion corresponding to the first fluid chamber  70 , and the second state in which the ink in the liquid chamber  57  is pressurized by the film  75  of the portions corresponding to the first fluid chamber  70  and the second fluid chamber  71 . It is configured to be capable of executing a plurality of pressure cleanings with different discharge amounts of the ink. Although the flexible member  51  is illustrated as being parallel to the opening surface of the fluid chamber  58  as a whole in  FIG. 4 , the film  75  in the flexible member  51  may be slightly bent to the fluid chamber  58  side. 
     Hereinafter, a maintenance operation (in other words, pressure cleaning) for forcibly discharging ink and air bubbles from the nozzles  30  of the recording head  10  using the pressure adjustment section  54  will be described. 
       FIG. 7  is a sectional view of the pressure adjustment section  54  illustrating a state in which first pressure cleaning is performed, and  FIG. 8  is a sectional view of the pressure adjustment section  54  illustrating a state in which second pressure cleaning is performed. The pressure adjustment section  54  according to the present disclosure controls the amount of gas flowing into the fluid chamber  58 , that is, controls the driving time of the air pump  16 , so that pressure cleaning of a plurality of patterns, in which the discharge amount of the ink from the nozzle  30  is different, can be selectively performed. That is, it is possible to execute the first pressure cleaning of pressurizing the flexible member  51  by the gas flowing into the first fluid chamber  70  in the first state, and the second pressure cleaning of pressurizing the flexible member  51  by the gas flowing into the first fluid chamber  70  and the second fluid chamber  71  in the second state. When such pressure cleaning is performed, the recording head  10  is positioned at the home position, and control is performed such that ink or the like is discharged from each nozzle  30  toward the capping mechanism  11 . Further, prior to the pressure cleaning, the flow path opening/closing section  55  is closed. Therefore, in the pressure cleaning, the ink in the liquid chamber  57  is prevented from flowing backward to the flow path opening/closing section  55  side. 
     In the first pressure cleaning, when the air pump  16  is driven in the above-described normal state to cause the gas to flow from the vent  59   a  into the first fluid chamber  70  of the fluid chamber  58 , and the pressure inside the first fluid chamber  70  increases, the seal portion  76  of the flexible member  51  is regulated from being deformed toward the liquid chamber  57  by the regulation member  78 . Therefore, as illustrated in  FIG. 7 , the film  75  of a portion inside the sealed portion, in which the seal portion  76  comes into contact with the support member  77 , that is, a portion corresponding to the first fluid chamber  70  is bent and deformed toward the liquid chamber  57 . Therefore, a volume of the liquid chamber  57  is reduced to pressurize the ink inside thereof, and the ink in the liquid chamber  57  is sent from the ink outlet  68   a  to the liquid ejecting unit  23  side through the third flow path  68 . Therefore, ink or the like in the flow path inside thereof is discharged from each nozzle  30  of the liquid ejecting unit  23  toward the capping mechanism  11 . In the first pressure cleaning, the first state, in which the first fluid chamber  70  and the second fluid chamber  71  in the fluid chamber  58  do not communicate with each other, is maintained. As described above, in the first pressure cleaning, the discharge amount of the ink from each nozzle  30  of the recording head  10  becomes a first amount corresponding to a variation of the volume of the liquid chamber  57  due to the deformation of only the film  75  corresponding to the first fluid chamber  70 . The first pressure cleaning is executed, for example, for the purpose of removing the foreign matter such as paper dust adhering to the vicinity of the nozzle  30  on the nozzle formation surface. 
     In the second pressure cleaning, the driving time of the air pump  16  is set longer than that in the first pressure cleaning. When the driving of the air pump  16  is continued exceeding the driving time of the air pump  16  at the time of the first pressure cleaning from the state in which the film  75  of the portion corresponding to the first fluid chamber  70  is pressurized and bent to the liquid chamber  57  side, the pressure inside the first fluid chamber  70  is further increased, and the flexible member  51  is pulled toward the liquid chamber  57  as a whole. Therefore, a film thickness of the seal portion  76  being pressed to the regulation member  78  side gradually decreases. When the pressure inside the fluid chamber  58  exceeds a predetermined threshold, as illustrated in  FIG. 8 , a gap G is generated between the seal portion  76  and the support member  77 . Therefore, the first fluid chamber  70  and the second fluid chamber  71  communicate with each other through the gap G in the second state. In the second state, since the gas from the vent  59   a  also flows into the second fluid chamber  71 , the film  75  of the flexible member  51  is pressurized by both the first fluid chamber  70  and the second fluid chamber  71 , and the ink in the liquid chamber  57  is in the pressurized state by the deformation of the film  75 . That is, the film  75  in the portions corresponding to the first fluid chamber  70  and the film  75  in the portion corresponding to the second fluid chamber  71  are bent and deformed toward the liquid chamber  57 . As described above, the volume of the liquid chamber  57  is further reduced and the ink inside the liquid chamber  57  is pressurized by the deformation of the film  75  of the portion corresponding to the first fluid chamber  70  and the deformation of the film  75  of the portion corresponding to the second fluid chamber  71 . More ink is sent from the ink outlet  68   a  to the liquid ejecting unit  23  side, and the ink is discharged from each nozzle  30  of the liquid ejecting unit  23 . In the second pressure cleaning, the discharge amount of the ink from each nozzle  30  of the recording head  10  becomes a second amount (&gt;first amount) corresponding a sum of a volume fluctuation of the liquid chamber  57  due to the deformation of the film  75  corresponding to the first fluid chamber  70  and a volume fluctuation of the liquid chamber  57  due to the deformation of the film  75  corresponding to the second fluid chamber  71 . The second pressure cleaning is executed, for example, for the purpose of removing thickened ink and air bubbles in the flow path inside the recording head  10 . 
     With respect to a maximum value of the discharge amount in the pressure cleaning, for example, the top portion of the film  75  deformed toward the liquid chamber  57  comes into contact with the ceiling surface or the like of the liquid chamber  57  to regulate the deformation of the film  75 , and thereby the adjustment may be performed. Further, for example, the adjustment may be performed by a sensor for detecting the deformation of the film  75  in the liquid chamber  57 , a sensor for detecting the pressure in the fluid chamber  58 , or the like. 
       FIG. 9  is a schematic graph for explaining a relationship between the driving time of the air pump  16  and the discharge amount of the ink from the nozzle  30  in pressure cleaning, and in which a horizontal axis represents the driving time of the air pump  16 , and a vertical axis represents the discharge amount, respectively. As illustrated in the drawing, when the driving of the air pump  16  is started in the first state (time point t 0 ), the film  75  corresponding to the first fluid chamber  70  in the flexible member  51  is deformed to the liquid chamber  57  side and the ink is sent from the liquid chamber  57  to the recording head  10  side by pressurization of the inside of the first fluid chamber  70 . Therefore, the ink is discharged from each nozzle  30 . As the driving of the air pump  16  is continued, the discharge amount of the ink increases at a substantially constant rate, but when the film  75  of the portion described above is deformed to a certain extent, it becomes difficult to deform any more. Therefore, after the time point ta, the increase rate in the discharge amount temporarily decreases. 
     After that, the driving of the air pump  16  is continued, and at time point tc after time point tb, as described above, the pressure inside the first fluid chamber  70  exceeds the threshold, and a gap is generated between the first seal portion  76  and the support member  77  in the fluid chamber  58 . The first fluid chamber  70  and the second fluid chamber  71  communicate with each other through the gap in the second state. Therefore, the flexible member  51  is pressurized by both the film  75  corresponding to the first fluid chamber  70  and the film  75  corresponding to the second fluid chamber  71  in the flexible member  51 , and the ink in the liquid chamber  57  is pressurized, so that the discharge amount of the ink increases again at a constant rate as the driving of the air pump  16  is continued. Thereafter, when the film  75  corresponding to the second fluid chamber  71  is deformed to a certain extent, it becomes difficult to deform any more, so that the discharge amount is hardly increased even if the air pump  16  is continuously driven after time point td. In the present embodiment, the driving time of the air pump  16  in the first pressure cleaning is set to a time T 1  from time point t 0  to time point tb between time point ta and time point tc. Further, the driving time of the air pump  16  in the second pressure cleaning is set to a time T 2  from the time point t 0  to the time point td. As described above, a region from the time point ta to the time point tc when the increase rate of the discharge amount decreases in the middle of the region where the discharge amount increases at a predetermined rate is generated. Therefore, some error is allowed in setting of the execution time of the first pressure cleaning, that is, the driving time T 1  of the air pump  16 . Further, in the flexible member  51 , for example, the deformation amount of the film  75  may fluctuate according to a temperature change, but in the present embodiment, the area of the film  75  contributing to the pressurization in the first state is smaller than that in the configuration of the related art. Therefore, it is possible to reduce the error in the deformation amount due to the temperature change. 
     As described above, in the printer  1  according to the present disclosure, two types of pressure cleanings of the first pressure cleaning and the second pressure cleaning in which the discharge amounts of ink are different depending on the driving time of the air pump  16 , that is, the supply time of the gas can be executed with a simpler configuration without requiring complicated mechanism, sensor, or the like. Therefore, excess and deficiency of the discharge amount of the ink in the pressure cleaning can be further reduced. In the present embodiment, the seal portion  76  is biased to the support member  77  side by the regulation member  78  which is a type of the bias member, so the sealability between the first seal portion  76  and the support member  77  in the first state can be enhanced. Therefore, the discharge amount of the ink in the pressure cleaning can be adjusted with higher accuracy. In addition, since the first state is converted to the second state when the pressure inside the first fluid chamber  70  exceeds the threshold, switching control of the pressure cleaning with different discharge amounts becomes easy. 
     In the present embodiment, a configuration, in which the liquid chamber is partitioned by the partition structure  69  into a total of two liquid chambers of the first fluid chamber  70  and the second fluid chamber  71 , is illustrated. However, a configuration, in which a third fluid chamber not in direct communication with the first fluid chamber  70  is formed outside the second fluid chamber  71 , can also be adopted by providing a plurality of partition structures  69 . Therefore, the liquid chamber is partitioned into a total of three or more fluid chambers, and it is possible to execute a plurality of pressure cleanings with different discharge amounts according to the number of the liquid chambers obtained by partitioning. A configuration in which the third fluid chamber is provided will be described later in a fourth embodiment. 
       FIGS. 10 and 11  are plan views illustrating the configuration of the pressure adjustment section  54  according to the second embodiment of the present disclosure, in which  FIG. 10  is a plan view for explaining the configuration of the pressure adjustment section  54  on the fluid chamber  58  side, and  FIG. 11  is a plan view for explaining the configuration of the pressure adjustment section  54  on the liquid chamber  57  side. The same reference numerals are given to the same portions as in the first embodiment, and the description thereof will be omitted as appropriate. In addition, since the cross section of the pressure adjustment section  54  in the present embodiment is substantially the same as those illustrated in  FIGS. 4, 7, and 8 . 
     In the first embodiment, the configuration, in which the fluid chamber  58  and the liquid chamber  57  in a plan view have circular shapes, is illustrated, but the configuration is not limited thereto, and a configuration having a rectangular shape in a plan view can also be adopted as in this embodiment. A flexible member  51  is also formed in a rectangular shape in accordance with the shapes of the fluid chamber  58  and the liquid chamber  57 . In the present embodiment, in the fluid chamber  58 , seal portions  76   a  and  76   b  as a first seal portion of the flexible member  51  respectively come into contact with two support members  77   a  and  77   b  provided in parallel at intervals on both sides of the vent  59   a  to seal the fluid chamber  58 . Therefore, the fluid chambers  58  is configured to be partitioned into three fluid chambers of the first fluid chamber  70  having the vent  59   a  and a total of two second fluid chambers  71   a  and  71   b  provided on both sides thereof. Further, in the liquid chamber  57 , two regulation members  78   a  and  78   b  are provided corresponding to the seal portions  76   a  and  76   b  of the flexible member  51 , and are urged toward the fluid chamber  58  by the urging members  79   a  and  79   b , respectively. Therefore, the seal portions  76   a  and  76   b  are respectively pressed, that is, biased to the support members  77   a  and  77   b  of the fluid chamber  58 . As described above, in the present embodiment, a total of two sets of partition structures formed of the urging member  79 , the seal portion  76 , and the support member  77  is provided at different positions. Partitioning provides a plurality of second fluid chambers  71 , that is, two second fluid chambers. Details of the urging members  79   a  and  79   b  will be described in a third embodiment. 
     Similar to the first embodiment, in the second embodiment, as long as the respective partition structures have the same configuration, two patterns of the pressure cleaning, in which the discharge amount of the ink from the nozzle  30  is different, can be performed by controlling the driving time of the air pump  16 . That is, the first pressure cleaning of pressurizing the flexible member  51  by the gas flowing into the first fluid chamber  70  in the first state, and the second pressure cleaning of pressurizing the flexible member  51  by the gas flowing into the first fluid chamber  70  and the second fluid chamber  71   a  and  71   b  in the second state can be executed. Further, three pressure cleanings can also be performed with different discharge amounts of ink from the nozzle  30  by making timing, at which the seal between the seal portion  76  and the support member  77  is released, different by changing the configuration of each partition structure. That is, a plurality of pressure cleanings can be executed according to the number of fluid chambers obtained by partitioning by the partition structure. 
     For example, the timing, at which the seal between the seal portion  76  and the support member  77  is released, can be different for each partition structure by making a thickness of the seal portions  76   a  and  76   b  different for each partition structure. Specifically, a distance between the regulation member  78  and the support member  77  is constant in each partition structure, and a thickness of the seal portion  76   a  is thinner than a thickness of the seal portion  76   b . Therefore, when the flexible member  51  is pressurized, a gap is more likely to be generated in the seal portion between the seal portion  76   a  and the support member  77   a , than that in the seal portion between the seal portion  76   b  and the support member  77   b . As described above, the timing, at which the seal between the support member  77  and the seal portion  76  is released, can be made different for each partition structure depending on the thickness of the seal portion  76 . Further, assuming that the thickness of the seal portion  76  is constant in each partition structure, timing for releasing the seal between the seal portion  76  and the support member  77  can be different for each partition structure by making the distance between the regulation member  78  and the support member  77  different each partition structure. That is, for example, when the flexible member  51  is pressurized by making the distance between the regulation member  78   a  and the support member  77   a  larger than the distance between the regulation member  78   b  and the support member  77   b , a gap is more likely to be generated in the seal portion between the seal portion  76   a  and the support member  77   a  than that in the seal portion between the seal portion  76   b  and the support member  77   b . Also, in these configurations, it is desirable that the thickness of the seal portion  76  is equal to or greater than the distance between the regulation member  78  and the support member  77  in a state of not coming into contact with any of the support member  77  and the regulation member  78 . 
       FIGS. 12 to 14  are sectional views for explaining a configuration of a pressure adjustment section  54  in a third embodiment of the present disclosure, in which  FIG. 12  illustrates a state in which first pressure cleaning is performed,  FIG. 13  illustrates a state in which second pressure cleaning is performed, and  FIG. 14  illustrates a state in which third pressure cleaning is performed. The same reference numerals are given to the same portions as in the first and second embodiments, and the description thereof will be omitted as appropriate. In the present embodiment, shapes of a fluid chamber  58  and a liquid chamber  57  in a plan view are rectangular as those in the second embodiment. A thickness of a seal portion  76  of a flexible member  51  in the present embodiment is set thicker than a thickness of a film  75 , so that the rigidity of the seal portion  76  is higher than the rigidity of the film  75 . The seal portion  76  is integrally formed with a main body (film  75 ) of the flexible member  51 , and is configured by partially increasing the thickness of the flexible member  51 . For the seal portion  76 , a plurality of films of the same material as the flexible member  51  may be stacked, so that the thickness thereof is thicker than the thickness of the film  75 , or the thickness thereof may be thicker than the thickness of the film  75  by joining a material (for example, a material having a rigidity higher than that of a material of the flexible member  51 , or the like) different from that of the flexible member  51  or bonding with an adhesive or the like. The flexible member  51  in the present embodiment is provided with two seal portions  76   a  and  76   b  at different positions. 
     Further, the support member  77  in the first embodiment is not provided in the fluid chamber  58  in the present embodiment, and a bottom surface of the fluid chamber  58  is formed flat. The seal portions  76   a  and  76   b  of the flexible member  51  are in direct contact with the bottom surface of the fluid chamber  58  to seal the fluid chamber  58 , so that the fluid chamber  58  is configured to be partitioned into a first fluid chamber  70  and two second fluid chambers  71   a  and  71   b . Therefore, in the present embodiment, portions in the bottom surface of the fluid chamber  58  coming into contact with the seal portions  76   a  and  76   b  are the support portions  80   a  and  80   b , respectively, and the support portions  80   a  and  80   b  are the first contact portion in the present disclosure. 
     Further, in the liquid chamber  57  in the present embodiment, an urging member  79  (a type of the elastic member in the present disclosure) such as a spring of which one end is fixed to the ceiling surface  57   a  is provided as a bias member. As the spring, those of various configurations such as a coil spring, a leaf spring, and an S-shaped spring can be adopted. In the present embodiment, two urging members  79   a  and  79   b  are provided corresponding to the seal portions  76   a  and  76   b  of the flexible member  51 . The seal portions  76   a  and  76   b  are urged toward the fluid chamber  58  by the urging members  79   a  and  79   b . Therefore, the seal portions  76   a  and  76   b  are biased to the fluid chamber  58  side, and respectively come into contact with the support portions  80   a  and  80   b  on the bottom surface of the fluid chamber  58  in the first state to seal the fluid chamber  58 . Therefore, in the first state, the fluid chamber  58  is configured to be partitioned into three fluid chambers of the first fluid chamber  70  having the vent  59   a  and the two second fluid chambers  71   a  and  71   b  provided on both sides thereof. That is, the set of the urging member  79   a , the seal portion  76   a , and the support portion  80   a , and the set of the urging member  79   b , the seal portion  76   b , and the support portion  80   b  in the present embodiment respectively configure the partition structures  69   a  and  69   b.    
     In the present embodiment, the timing, at which the seal between the seal portion  76  and the support portion  80  in each partition structure is released, is made different by changing the configuration of each partition structure  69   a  and  69   b , and it is possible to perform three pressure cleanings of different discharge amounts of the ink from the nozzle  30 . More specifically, the timing, at which the seal between the seal portion  76  and the support member  77  is released, is made different for each partition structure by making spring constants of the urging members  79   a  and  79   b  of the partition structures  69   a  and  69   b  different. That is, when the flexible member  51  is pressurized, a gap is more likely to be generated in the seal portion between the seal portion  76   a  and the support member  77   a  than that in the seal portion between the seal portion  76   b  and the support member  77   b  by making the spring constant of the urging member  79   a  in the partition structure  69   a  smaller than the spring constant of the urging member  79   b  in the partition structure  69   b.    
     Also, in the present embodiment, it is possible to perform pressure cleaning of a plurality of patterns, in which the discharge amount of the ink from the nozzle  30  is different, by controlling the driving time of the air pump  16 . That is, it is possible to execute the first pressure cleaning of pressurizing the flexible member  51  by the gas flowing into the first fluid chamber  70 , the second pressure cleaning of pressurizing the flexible member  51  by the gas flowing into the first fluid chamber  70  and the second fluid chamber  71   a , and the third pressure cleaning of pressurizing the flexible member  51  by the gas flowing into the first fluid chamber  70 , the second fluid chamber  71   a , and the second fluid chamber  71   b.    
     In the first pressure cleaning, when the air pump  16  is driven to cause the gas to flow from the vent  59   a  into the first fluid chamber  70  and the pressure inside the first fluid chamber  70  to increase, as illustrated in  FIG. 12 , the film  75  corresponding to the first fluid chamber  70  is deformed so as to bend toward the liquid chamber  57 . Therefore, a volume of the liquid chamber  57  is reduced to pressurize the ink inside thereof, and the ink in the liquid chamber  57  is sent from the ink outlet  68   a  to the liquid ejecting unit  23  side through the third flow path  68 . Therefore, the ink is discharged from the nozzle  30 . 
     When the driving of the air pump  16  is continued exceeding the driving time of the air pump  16  set at the time of the first pressure cleaning from a state in which the film  75  corresponding to the first fluid chamber  70  is pressurized and bent toward the liquid chamber  57 , the pressure inside the first fluid chamber  70  is further increased, and the seal portions  76   a  and  76   b  in the partition structures  69   a  and  69   b  are gradually displaced to the liquid chamber  57  side while resisting against a urging force of the urging member  79 a. In the present embodiment, as described above, since the spring constant of the urging member  79   a  is smaller than the spring constant of the urging member  79   b , when the pressure inside the fluid chamber  58  exceeds a first predetermined threshold, as illustrated in  FIG. 13 , a gap G is previously generated between the seal portion  76   a  and the support portion  80   a  in the partition structure  69   a . Therefore, the first fluid chamber  70  and the second fluid chamber  71   a  communicate with each other through the gap G in is the second state. In this second state, the gas from the vent  59   a  also flows into the second fluid chamber  71   a , so the flexible member  51  is pressurized by both the first fluid chamber  70  and the second fluid chamber  71   a  to create a state in which the ink in the liquid chamber  57  is pressurized. Therefore, the second pressure cleaning, in which the discharge amount of the ink is larger than that of the first pressure cleaning, can be performed. 
     When the driving of the air pump  16  is continued exceeding the driving time of the air pump  16  set at the time of the second pressure cleaning from a state in which the film  75  corresponding to the first fluid chamber  70  and the second fluid chamber  71   a  is pressurized and bent toward the liquid chamber  57 , the pressure inside the fluid chamber  58  is further increased, and when the pressure inside the fluid chamber  58  exceeds a second predetermined threshold, as illustrated in  FIG. 14 , a gap G is generated between the seal portion  76   b  and the support portion  80   b  in the partition structure  69   b . Therefore, the first fluid chamber  70 , the second fluid chamber  71   a , and the second fluid chamber  71   b  communicate with each other through the gap G in the third state. In the third state, the gas from the vent  59   a  also flows into the second fluid chamber  71   b , so that the flexible member  51  is pressurized by the three fluid chambers of the first fluid chamber  70 , the second fluid chamber  71   a , and the second fluid chamber  71   b  to create a state in which the ink inside the liquid chamber  57  is pressurized. Therefore, the third pressure cleaning, in which the discharge amount of the ink is larger than that in the second pressure cleaning, can be performed. 
     In the present embodiment, since the rigidity of the seal portion  76  is higher than the rigidity of the film  75 , when the seal portion  76  ( 76   a  and  76   b ) and the support portion  80  ( 80   a  and  80   b ) come in contact with each other, the sealability between the first fluid chamber  70  and the second fluid chambers  71   a  and  71   b  is enhanced. Therefore, the discharge amount of the ink in the pressure cleaning can be adjusted with higher accuracy. Further, in the present embodiment, since the seal portion  76  and the support portion  80  are sealed by the urging force of the urging member  79 , the timing, at which the seal between the seal portion  76  and the support portion  80  in each partition structure  69   a  and  69   b  is released, can be arbitrarily adjusted by changing the spring constant of the urging member  79 . The elastic member in the present disclosure is not limited to the urging member such as a spring, and may be made of, for example, an elastic member such as rubber. In this case, the timing, at which the seal between the seal portion  76  and the support portion  80  in each partition structure is released in each partition structure, is different by changing the elastic modulus of the elastic member for each partition structure, and a plurality of pressure cleanings, in which the discharge amount of the ink from the nozzle  30  is different, can be performed. 
       FIGS. 15 to 17  are sectional views for explaining a configuration of a pressure adjustment section  54  in a fourth embodiment of the present disclosure, in which  FIG. 15  illustrates a state in which first pressure cleaning is performed.  FIG. 16  illustrates a state in which second pressure cleaning is performed, and  FIG. 17  illustrates a state in which third pressure cleaning is performed. The same reference numerals are given to the same portions as in each of the embodiments described above, and the description thereof will be omitted as appropriate. A flexible member  51  in the present embodiment is provided with a first seal portion  76   a  and a second seal portion  76   b  at a position different from the first seal portion  76   a , and they are respectively urged by urging members  79   a  and  79   b . Therefore, the seal portions  76   a  and  76   b  are biased to the fluid chamber  58  side, and respectively come into contact with the support portions  80   a  and  80   b  on the bottom surface of the fluid chamber  58  in the first state to seal the fluid chamber  58 . 
     In the present embodiment, a vent  59   a  is open on a side surface of a fluid chamber  58 . Therefore, in the state in which the seal portions  76   a  and  76   b  come into contact with the support portions  80   a  and  80   b  and are sealed (that is, in a first state), it is partitioned into three fluid chambers of a first fluid chamber  70  having the vent  59   a , a second fluid chamber  71  adjacent to the first fluid chamber  70  via a partition structure  69   a , and a third fluid chamber  84  (corresponding to the third fluid chamber in the present disclosure) adjacent to the second fluid chamber  71  via a partition structure  69   b  in order from the left in  FIG. 15 . The third fluid chamber  84  is a fluid chamber not directly adjacent to the first fluid chamber  70 . The second seal portion  76   b  in the present embodiment is a type of the second seal portion in the present disclosure, and the corresponding support portion  80   b  is a type of the second contact portion in the present disclosure. The set of the urging member  79   a , the seal portion  76   a , and the support portion  80   a , and the set of the urging member  79   b , the seal portion  76   b , and the support portion  80   b  in the present embodiment respectively configure the partition structures  69   a  and  69   b.    
     Also, in the present embodiment, it is possible to perform pressure cleaning of a plurality of patterns, in which the discharge amount of the ink from the nozzle  30  is different, by controlling the driving time of the air pump  16 . That is, it is possible to execute the first pressure cleaning of pressurizing the flexible member  51  by the gas flowing into the first fluid chamber  70 , the second pressure cleaning of pressurizing the flexible member  51  by the gas flowing into the first fluid chamber  70  and the second fluid chamber  71 , and the third pressure cleaning of pressurizing the flexible member  51  by the gas flowing into the first fluid chamber  70 , the second fluid chamber  71 , and the third fluid chamber  84 . 
     In the first pressure cleaning, the air pump  16  is driven to cause the gas to flow from the vent  59   a  opened on the side surface of the fluid chamber  58  into the first fluid chamber  70 . When the pressure inside the first fluid chamber  70  increases, as illustrated in  FIG. 15 , the film  75  corresponding to the first fluid chamber  70  is bent and deformed toward the liquid chamber  57 . Therefore, a volume of the liquid chamber  57  is reduced to pressurize the ink inside thereof, and the ink in the liquid chamber  57  is sent from the ink outlet  68   a  to the liquid ejecting unit  23  side through the third flow path  68 . Therefore, the ink is discharged from the nozzle  30 . 
     When the driving of the air pump  16  is continued exceeding the driving time of the air pump  16  set at the time of the first pressure cleaning from a state in which the film  75  corresponding to the first fluid chamber  70  is pressurized and bent toward the liquid chamber  57 , the pressure inside the first fluid chamber  70  is further increased, and the seal portion  76   a  in the partition structure  69   a  is gradually displaced to the liquid chamber  57  side while resisting against the urging force of the urging member  79   a . When the pressure inside the fluid chamber  58  exceeds a predetermined first threshold, as illustrated in  FIG. 16 , a gap G is generated between the seal portion  76   a  and the support portion  80   a  in the partition structure  69   a . Therefore, the first fluid chamber  70  and the second fluid chamber  71  communicate with each other through the gap G in the second state. In the second state, since the gas from the vent  59   a  also flows into the second fluid chamber  71 , the flexible member  51  is pressurized by both the first fluid chamber  70  and the second fluid chamber  71 , and the ink inside the liquid chamber  57  is in the pressurized state. Therefore, the second pressure cleaning, in which the discharge amount of the ink is larger than that of the first pressure cleaning, can be performed. 
     When the driving of the air pump  16  is continued exceeding the driving time of the air pump  16  set at the time of the second pressure cleaning from a state in which the film  75  corresponding to the first fluid chamber  70  and the second fluid chamber  71  is pressurized and bent toward the liquid chamber  57 , the pressure inside the fluid chamber  58  is further increased, and exceeds a second threshold, as illustrated in  FIG. 17 , a gap G is generated between the seal portion  76   b  and the support portion  80   b  in the partition structure  69   b . Therefore, the first fluid chamber  70 , the second fluid chamber  71 , and the third fluid chamber  84  communicate with each other through the gap G in the third state. In the third state, the gas from the vent  59   a  also flows into the third fluid chamber  84 , so that the pressure member  51  is pressurized by the three fluid chambers of the first fluid chamber  70 , the second fluid chamber  71 , and the third fluid chamber  84  to create a state in which the ink inside the liquid chamber  57  is pressurized. Therefore, the third pressure cleaning, in which the discharge amount of the ink is larger than that in the second pressure cleaning, can be performed. 
     The spring constants of the urging members  79  and  89   b  in the present embodiment may be the same or different. In any case, the seal between the seal portion  76   a  and the support portion  80   a  in the partition structure  69   a  may be released first, and then the seal between the seal portion  76   b  and the support portion  80   b  in the partition structure  69   b  may be released later. In the present embodiment, the configuration, in which only one third fluid chamber  84  is obtained by partitioning, is exemplified, but, for example, the third fluid chamber  84  can be partitioned into two or more by further increasing the partitioning structure. Therefore, it possible to execute pressure cleanings of more patterns with different discharge amounts. 
     Although the structure, in which the bias member, that is, the regulation member  78  and the urging member  79  are provided, is illustrated in each embodiment, if the seal can be taken between the seal portion  76  and the support member  77 , or between the seal portion  76  and the support portion  80 , the bias member is not an essential part. Further, the bias member is not limited to the regulation member  78  and the urging member  79  exemplified in each embodiment, but it is also possible to adopt, for example, a bias member that biases the seal portion to the contact portion of the fluid chamber by a magnetic force. That is, a configuration, in which magnets having mutually different polarities are provided in the seal portion and the contact portion, can be adopted. Alternatively, it is also possible to adopt a configuration in which a magnet is provided in either the seal portion or the contact portion, and a magnetic material capable of being adsorbed to the magnet is provided on the other side. In this case, the timing, at which the seal between the seal portion and the contact portion is released, can be arbitrarily adjusted by changing the magnetic force for each of a plurality of partition structures. 
     Also, for example, a configuration can be provided, in which a plurality of films  75  with different thicknesses (or different in rigidity) are provided in the flexible member  51 , the flexible member  51  is in a state (most thereof may come into contact therewith and also includes partially separated) of entirely coming into contact with the bottom surface of the fluid chamber  58  in the first state, and when the gas is supplied to the fluid chamber  58  to pressurize the inside thereof in the pressure cleaning, the film  75  with low rigidity is first deformed, and then the film  75  with high rigidity starts to deform. Therefore, it is possible to execute a plurality of pressure cleanings with different discharge amounts of liquid. 
     Although the ink jet recording head  10  which is a type of the liquid injection head is explained as an example above, the present disclosure can also be applied to another liquid ejecting head which has a pressure adjustment part, and a liquid ejecting apparatus provided with the liquid ejecting head. For example, the present disclosure can be applied to a color material ejecting head used for manufacturing a color filter such as a liquid crystal display, an electrode material ejecting head used to form an electrode such as an organic electro luminescence (EL) display or a surface emitting display (FED), and a liquid ejecting head provided with a plurality of bio-organic matter ejecting heads or the like used for manufacturing a biochip (biochemical element), and a liquid ejecting apparatus provided with the same. 
     In the following, technical ideas and their operational effects which are grasped from the above-described embodiments and modification examples will be described. 
     The liquid ejecting apparatus according to the present disclosure is proposed to achieve the above object, and includes a liquid ejecting unit ejecting a liquid from a nozzle; and a pressure adjustment section that adjusts a pressure of the liquid supplied to the liquid ejecting unit. The pressure adjustment section includes a liquid chamber communicating with the liquid ejecting unit and storing the liquid to be supplied to a liquid ejecting unit side, a fluid chamber into which a fluid is capable of flowing, a flexible member that includes an elastically deformable film and a first seal portion provided in the film, the flexible member being interposed between the liquid chamber and the fluid chamber to separate the liquid chamber and the fluid chamber, and a pressurizing section that supplies the fluid to the fluid chamber and pressurizes the flexible member toward the liquid chamber with the fluid. The fluid chamber includes a first contact portion configured to come into contact with the first seal portion, and the fluid chamber is configured such that the first contact portion and the first seal portion come in contact with each other so as to be partitioned into a first fluid chamber having an introduction port through which the fluid flows in and a second fluid chamber. The pressurizing section converts, by the supply of the fluid to the fluid chamber, a state of the fluid chamber into a first state in which the first contact portion and the first seal portion are in contact with each other, or a second state in which the contact between the first contact portion and the first seal portion is released so that the first fluid chamber and the second fluid chamber communicate with each other (first configuration). 
     According to the liquid ejecting apparatus of the present disclosure, it is possible to execute a plurality of pressure cleanings with different discharge amounts of the liquid from each nozzle with a simpler configuration, according to the driving time of the pressurizing section, that is, the supply time of the gas. 
     In the first configuration, it is possible to adopt a configuration in which the rigidity of the first seal portion is higher than the rigidity of the film (second configuration). 
     According to the configuration, since the rigidity of the first seal portion is higher than the rigidity of the film, it is possible to enhance the sealability when coming into contact with the first contact portion. Therefore, the discharge amount of the liquid in the pressure cleaning can be adjusted with higher accuracy. 
     In the first configuration, it is desirable that when a pressure in the first fluid chamber exceeds a threshold, the first state is converted into the second state (third configuration). 
     According to the configuration, when the pressure in the first fluid chamber exceeds the threshold, the first state is converted into the second state, so that switching control of pressure cleanings with different discharge amounts is easily performed. 
     Further, in the first configuration, it is desirable to adopt a configuration in which the liquid ejecting apparatus further includes a bias member biasing the first seal portion toward the first contact portion (fourth configuration). 
     According to the configuration, since the first seal portion is biased toward the first contact portion by the bias member, the sealability when the first seal portion comes into contact with the first contact portion can be enhanced. Therefore, the discharge amount of the liquid in the pressure cleaning can be adjusted with higher accuracy. 
     Furthermore, in the fourth configuration, it is desirable to adopt a configuration in which the bias member is a regulation member which is provided in the liquid chamber and regulates deformation of the first seal portion toward the liquid chamber, in the first state, the first seal portion comes into contact with the regulation member and the first contact portion so that the first fluid chamber and the second fluid chamber do not communicate with each other, and in the second state, the first seal portion is pressed toward the regulation member, and a gap is generated between the first seal portion and the first contact portion, so that the first fluid chamber and the second fluid chamber communicate with each other through the gap (fifth configuration). 
     According to the configuration, it is possible to switch between the first state in which the liquid in the liquid chamber is pressurized only by the film in the portion corresponding to the first fluid chamber, and the second state in which the liquid in the liquid chamber is pressurized by the film in the portions corresponding to the first fluid chamber and the second fluid chamber. Therefore, it is possible to perform a plurality of pressure cleanings with different discharge amounts of liquid. 
     In the fifth configuration, it is desirable to adopt a configuration in which in a state in which the contact between the first contact portion and the regulation member is released, a thickness of the first seal portion is equal to or more than a distance between the regulation member and the first contact portion (sixth configuration). 
     According to the configuration, the seal portion is in a crushed state between the first contact portion and the regulation member in the first state, and the first fluid chamber and the second fluid chamber can be more reliably blocked. 
     In the fifth configuration, it is possible to adopt a configuration in which a plurality of sets of partition structures formed of the first contact portion, the first seal portion, and the regulation member are provided at different positions, and the second fluid chamber is partitioned into a plurality of chambers by the plurality of sets of the partition structures (seventh configuration). 
     According to the configuration, it is possible to execute a plurality of pressure cleanings with different discharge amounts of liquid according to the number of fluid chambers obtained by partitioning. 
     Furthermore, in the seventh configuration, it is possible to adopt a configuration in which a thickness of the first seal portion is different for each partition structure (eighth configuration). 
     According to the configuration, the timing, at which the seal between the first contact portion and the first seal portion is released, can be made different for each partition structure according to the thickness of the first seal portion. 
     Further, in the seventh configuration, it is possible to adopt a configuration in which a distance between the regulation member and the first contact portion is different for each partition structure (ninth configuration). 
     According to the configuration, the timing, at which the seal between the first contact portion and the first seal portion is released, can be made different for each partition structure according to the distance between the regulation member and the first contact portion. 
     Furthermore, in the fourth configuration, it is desirable to adopt a configuration in which the bias member is formed of an elastic member that presses the first seal portion toward the first contact portion, in the first state, the elastic member causes the first seal portion and the first contact portion to come into contact with each other, so that the first fluid chamber and the second fluid chamber do not communicate with each other, and in the second state, the first seal portion is moved in a direction to resist an elastic force of the elastic member to create a gap between the first seal portion and the first contact portion, so that the first fluid chamber and the second fluid chamber communicate with each other through the gap (tenth configuration). 
     According to the configuration, it is possible to switch between the first state in which the liquid in the liquid chamber is pressurized only by the film in the portion corresponding to the first fluid chamber, and the second state in which the liquid in the liquid chamber is pressurized by the film in the portions corresponding to the first fluid chamber and the second fluid chamber. Therefore, it is possible to perform a plurality of pressure cleanings with different discharge amounts of liquid. 
     In the tenth configuration, it is possible to adopt a configuration in which a plurality of sets of partition structures formed of the first contact portion, the first seal portion, and the elastic member are provided at different positions, and the second fluid chamber is partitioned into a plurality of chambers by the plurality of sets of the partition structures (eleventh configuration). 
     According to the configuration, it is possible to execute a plurality of pressure cleanings with different discharge amounts of liquid according to the number of fluid chambers obtained by partitioning. 
     In the eleventh configuration, it is possible to adopt a configuration in which a plurality of elastic members are each constituted by a spring, and a spring constant of the spring is different for each partition structure (twelfth configuration). 
     According to the configuration, the timing, at which the seal between the first contact portion and the first seal portion is released, can be made different for each partition structure according to the spring constant of the spring which is the elastic member. 
     Alternatively, in the eleventh configuration, it is possible to adopt a configuration in which the plurality of elastic members are made of rubber, and an elastic modulus of the rubber is different for each partition structure (thirteenth configuration). 
     According to the configuration, the timing, at which the seal between the first contact portion and the first seal portion is released, can be made different for each partition structure according to the elastic modulus of the rubber which is the elastic member. 
     Alternatively, in the first configuration, it is possible to adopt a configuration in which the flexible member includes a second seal portion provided at a position different from the first seal portion, the fluid chamber includes a second contact portion configured to come into contact with the second seal portion, and the fluid chamber is configured to be partitioned by the contact between the second contact portion and the second seal portion to obtain a third fluid chamber, the second state is a state in which the second contact portion and the second seal portion come into contact with each other, and the pressurizing section releases the contact between the second contact portion and the second seal portion by the supplying the fluid to the fluid chamber, and converts the second state into a third state in which the second fluid chamber and the third fluid chamber communicate with each other (fourteenth configuration). 
     According to the configuration, it is possible to switch between the first state in which the liquid in the liquid chamber is pressurized only by the film in the portion corresponding to the first fluid chamber, the second state in which the liquid in the liquid chamber is pressurized by the film in the portions corresponding to the first fluid chamber and the second fluid chamber, and the third state in which the liquid in the liquid chamber is pressurized by the film in the portions corresponding to the first fluid chamber, the second fluid chamber, and the third fluid chamber. Therefore, it is possible to perform a plurality of pressure cleanings with different discharge amounts of liquid. 
     A maintenance method of the liquid ejecting apparatus of the present disclosure is a maintenance method of the liquid ejecting apparatus including the first configuration, the method including: first pressure cleaning of pressurizing the flexible member by the fluid flowing into the first fluid chamber in the first state; and second pressure cleaning of pressurizing the flexible member by the fluid flowing into the first fluid chamber and the second fluid chamber in the second state, in which the first pressure cleaning and the second pressure cleaning are switched in accordance with a supply time of the fluid by the pressurizing section. 
     According to the maintenance method, it is possible to execute a plurality of pressure cleanings with different discharge amounts of the liquid from each nozzle with a simpler configuration, according to the driving time of the pressurizing section, that is, the supply time of the gas. 
     A maintenance method of the liquid ejecting apparatus of the present disclosure is a maintenance method of the liquid ejecting apparatus including the fourteenth configuration, the method including: first pressure cleaning of pressurizing the flexible member by the fluid flowing into the first fluid chamber in the first state; second pressure cleaning of pressurizing the flexible member by the fluid flowing into the first fluid chamber and the second fluid chamber in the second state; and third pressure cleaning of pressurizing the flexible member by the fluid flowing into the first fluid chamber, the second fluid chamber, and the third fluid chamber in the third state, in which the first pressure cleaning, the second pressure cleaning, and the third pressure cleaning are switched in accordance with a supply time of the fluid by the pressurizing section. 
     According to the maintenance method, it is possible to execute a plurality of pressure cleanings with different discharge amounts of the liquid from each nozzle with a simpler configuration, according to the driving time of the pressurizing section, that is, the supply time of the gas. 
     In the second configuration, it is desirable to adopt a configuration in which when a pressure in the first fluid chamber exceeds a threshold, the first state is converted into the second state (seventeenth configuration). 
     According to the configuration, when the pressure in the first fluid chamber exceeds the threshold, the first state is converted into the second state, so that switching control of pressure cleanings with different discharge amounts is easily performed. 
     Further, in the second configuration, it is desirable to adopt a configuration in which the liquid ejecting apparatus further includes a bias member biasing the first seal portion toward the first contact portion (eighteenth configuration). 
     According to the configuration, since the first seal portion is biased toward the first contact portion by the bias member, the sealability when the first seal portion comes into contact with the first contact portion can be enhanced. Therefore, the discharge amount of the liquid in the pressure cleaning can be adjusted with higher accuracy. 
     Further, in the third configuration, it is desirable to adopt a configuration in which the liquid ejecting apparatus further includes a bias member biasing the first seal portion toward the first contact portion (nineteenth configuration). 
     According to the configuration, since the first seal portion is biased toward the first contact portion by the bias member, the sealability when the first seal portion comes into contact with the first contact portion can be enhanced. Therefore, the discharge amount of the liquid in the pressure cleaning can be adjusted with higher accuracy. 
     Further, in the seventeenth configuration, it is desirable to adopt a configuration in which the liquid ejecting apparatus further includes a bias member biasing the first seal portion toward the first contact portion (twentieth configuration). 
     According to the configuration, since the first seal portion is biased toward the first contact portion by the bias member, the sealability when the first seal portion comes into contact with the first contact portion can be enhanced. Therefore, the discharge amount of the liquid in the pressure cleaning can be adjusted with higher accuracy.