JP2016147468A - Liquid jet device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid jet device capable of suppressing deposition of a liquid component on a valve body.SOLUTION: A liquid jet device comprises: a pressure adjustment valve comprising a primary chamber coupled to liquid storage means 8 via a supply channel, a secondary chamber communicated with the primary chamber via a communication channel on which a valve body is provided, and a pressure reception film body for opening and closing the valve body in atmosphere reference; and a head body for jetting the liquid supplied from the secondary chamber. The liquid jet device further comprises; opening and closing means 131 disposed between the liquid storage means 8 and the primary chamber, and opening and closing the supply channel; and volume expansion means 132 for increasing a volume of the channel, between the channels between the opening and closing means 131 and the primary chamber. The liquid jet device comprises a first mode in which the valve body closes the communication channel, a second mode in which the valve body opens the communication channel, and a third mode in which the opening and closing means 131 closes the supply channel, and the volume expansion means 132 expands a volume of the channel, and after liquid jet by the head body, the mode is switched to the third mode from the first mode.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a liquid ejecting apparatus including a pressure adjusting valve that is provided in the middle of a flow path to open and close the flow path, and a head body that ejects liquid.

  As a liquid ejecting apparatus that ejects a liquid onto an ejected medium, for example, an ink jet recording apparatus that ejects ink as a liquid and performs printing on a paper, a recording sheet, or the like as an ejected medium is known.

  In such an ink jet recording apparatus, ink is supplied from a liquid storage means such as an ink tank to an ink jet recording head via a supply pipe such as a tube, and the ink supplied from the ink tank is used as a nozzle of the ink jet recording head. Some ejected as ink droplets from the opening. Further, there has been proposed an apparatus in which a pressure adjusting valve is provided in the middle of the flow path so that ink supplied from the liquid storage means is supplied to the ink jet recording head at a predetermined pressure (for example, Patent Document 1). And 2).

  The pressure regulating valve includes a valve seat and a valve body, and closes the flow path when the valve body comes into contact with the valve seat, and opens the flow path when the valve body is separated from the valve seat. It is like that. Such opening and closing of the valve seat and the valve body is performed by the pressure in the downstream flow path.

JP 2010-208048 A JP2013-132894A

  However, when the valve body and the valve seat of the pressure regulating valve repeatedly come into contact with each other, a component contained in the liquid accumulates, and the problem of blockage due to poor contact between the valve body and the valve seat due to the deposit occurs. is there.

  In particular, in the liquid ejecting head, when the pressure regulating valve is closed badly, the liquid leaks to cause liquid dripping from the nozzle opening, which contaminates the ejected medium or the liquid ejecting apparatus. is there.

  Such a problem is not limited to the ink jet recording apparatus, and similarly exists in a liquid ejecting apparatus that ejects liquid other than ink.

  SUMMARY An advantage of some aspects of the invention is that it provides a liquid ejecting apparatus capable of suppressing liquid leakage by suppressing deposition of liquid components.

An aspect of the present invention that solves the above problems includes a primary chamber that is connected to a liquid storage unit that stores a liquid via a supply path, a secondary chamber that is separated from the primary chamber by a partition, and the partition A surface that opens on the primary chamber side of the partition wall as a valve seat, and opens and closes the communication channel by contacting and separating from the valve seat And a pressure regulating valve that seals the opening of the secondary chamber and opens and closes the valve body with reference to atmospheric pressure, and from the secondary chamber of the pressure regulating valve A liquid ejecting apparatus comprising: a head main body that ejects the supplied liquid from a nozzle opening and is provided between the liquid storage unit and the primary chamber; An opening / closing means for opening and closing, and the opening / closing means and the first chamber between the primary chamber A first mode in which the valve body is in contact with the valve seat and closes the communication flow path, and is provided in a flow path including a chamber and increases the volume of the flow path. And the second mode in which the valve body is separated from the valve seat to open the communication flow path, the supply path is closed by the opening / closing means, and the volume of the flow path is expanded by the volume expansion means. A control unit capable of switching between the first mode and the third mode, wherein the control unit switches from the first mode to the third mode after the liquid is ejected by the head body. In the device.
In such an aspect, by performing the third mode, the state in which the valve body and the valve seat in the first mode contact each other with high pressure is shortened, and the valve body and the valve seat in the second mode are compared. It is possible to make a contact state with a relatively low pressure. Therefore, accumulation due to liquid aggregation can be suppressed. Moreover, since the pressure which a valve body and a valve seat contact can be reduced, without reducing the urging | biasing force of the urging means which urges | biases a valve body, it can suppress that a reactivity falls. At the same time, liquid leakage can be suppressed.

  Here, the volume expanding means comprises a pressure adjusting chamber separated by the flow path and the adjusting wall, and a pressure feeding means connected to the pressure adjusting chamber and pumping fluid to the pressure adjusting chamber, The adjustment wall is movably provided in the pressure adjustment chamber, and the adjustment wall is urged by an urging means in a direction to increase the volume of the flow path in the pressure adjustment chamber, and the volume expansion Preferably, the means stops the pumping of the fluid to the pressure adjusting chamber by the pumping means, so that the volume of the flow path is increased by the biasing force of the biasing means. According to this, the volume of the flow path can be easily expanded by the volume expanding means.

  Further, the control means includes a clock means for measuring an elapsed time after the ejection of the liquid from the head body is completed, and the control means performs the first operation based on the elapsed time measured by the clock means. It is preferable to switch from the first mode to the third mode. According to this, when the printing stop time is short, it is possible to shift directly from the first mode to the second mode, and it is possible to start printing in a short time.

1 is a plan view of a recording apparatus according to Embodiment 1 of the invention. It is a block diagram which shows the ink supply system which concerns on Embodiment 1 of this invention. FIG. 3 is a cross-sectional view of the recording head according to the first embodiment of the invention. It is sectional drawing of the head main body which concerns on Embodiment 1 of this invention. It is principal part sectional drawing of the pressure control valve which concerns on Embodiment 1 of this invention. It is principal part sectional drawing of the pressure control valve which concerns on Embodiment 1 of this invention. It is sectional drawing which shows the volume expansion means based on Embodiment 1 of this invention. It is principal part sectional drawing of the pressure control valve which concerns on Embodiment 1 of this invention. FIG. 3 is a block diagram illustrating a control configuration of the recording apparatus according to the first embodiment of the invention. It is principal part sectional drawing of the volume expansion means which concerns on other embodiment of this invention.

Hereinafter, the present invention will be described in detail based on embodiments.
(Embodiment 1)
FIG. 1 is a plan view of an ink jet recording apparatus which is an example of a liquid ejecting apparatus according to Embodiment 1 of the present invention, and FIG. 2 is a diagram illustrating an ink supply system of the ink jet recording apparatus.

  As shown in FIG. 1, an ink jet recording apparatus 1 includes a main body frame 2 that is a main body of the present embodiment having a rectangular shape in plan view. In the main body frame 2, a medium support member 3 that supports an ejected medium (not shown) extends along a first direction X that is a main scanning direction. A medium to be ejected such as paper is fed onto the medium support member 3 along a second direction Y orthogonal to the first direction X, which is the sub-scanning direction, by a paper feed mechanism (not shown). Yes. A rod-shaped guide shaft 4 extending in parallel with the first direction X of the medium support member 3 is installed above the medium support member 3 in the main body frame 2.

  A carriage 5 is supported on the guide shaft 4 so as to be capable of reciprocating in the first direction X along the guide shaft 4. The carriage 5 is connected to a carriage motor 7 provided on the main body frame 2 via an endless timing belt 6 that is hung between a pair of pulleys 6 a provided on the main body frame 2. Thus, the carriage 5 is reciprocated along the guide shaft 4 by driving the carriage motor 7.

  The carriage 5 holds an ink jet recording head 15 (hereinafter also simply referred to as a recording head 15), which is an example of the liquid ejecting head of the present embodiment. The recording head 15 of the present embodiment includes a head main body 20 and a pressure adjusting valve 50 that supplies ink from the ink tank 8 serving as a liquid storage unit to the head main body 20.

  As will be described in detail later, a plurality of nozzle openings are provided on the surface of the recording head 15 facing the medium support member 3, and by driving a pressure generating means (not shown) provided in the recording head 15. The ink droplets are ejected from the nozzle openings onto the ejection target medium fed onto the medium support member 3 so that the dots are landed by the ink droplets, that is, printing is performed.

  A tank holder 9 is provided on one end side of the main body frame 2 in the first direction X, and an ink tank 8 which is a liquid storage means is detachably attached to the tank holder 9. In the present embodiment, one ink tank 8 is provided. Of course, the number of ink tanks 8 is not particularly limited, and two or more ink tanks 8 may be provided.

  The ink tank 8 attached to the tank holder 9 is connected to the pressure regulating valve 50 of this embodiment via a supply pipe 10 such as a tube having a supply path provided therein. The pressure adjustment valve 50 temporarily stores ink supplied from the ink tank 8 via the supply pipes 10, and the temporarily stored ink is supplied to the head body 20. In the present embodiment, although not particularly illustrated, a pumping unit that pumps the ink in the ink tank 8 toward the recording head 15 is provided in the middle of the tank holder 9 or the supply pipe 10. Examples of the pressure feeding unit include a pressing unit that presses the ink tank 8 from the outside, a pressure pump, and the like. As the pressure feeding means, a water head pressure difference generated by adjusting the vertical relative position between the recording head 15 and the ink tank 8 may be used.

  A maintenance unit 11 for performing maintenance such as cleaning of the head main body 20 is provided in a position near one end in the first direction X in the main body frame 2 and in the home position area of the carriage 5. The maintenance unit 11 includes a cap 12 for contacting the head body 20 so as to surround each nozzle opening of the head body 20 and receiving ink discharged from each nozzle opening by flushing. A suction pump (not shown) capable of suction.

  Then, with the cap 12 in contact with the head main body 20 so as to surround each nozzle opening of the head main body 20, the inside of the cap 12 is sucked by a suction pump (not shown), thereby increasing the viscosity of the ink from each nozzle opening. So-called cleaning is performed in which bubbles or the like are forcibly discharged into the cap 12.

  As shown in FIGS. 1 and 2, an opening / closing valve 131, which is an opening / closing means, is provided in the middle of the supply pipe 10 that supplies the ink in the ink tank 8 to the recording head 15 as a volume expansion unit 13 of this embodiment. The volume expanding means 132 is provided.

  Further, as shown in FIG. 1, the main body frame 2 is provided with a control device 14 which is a control means of this embodiment. The control device 14 controls printing based on a print signal input from the outside. The control device 14 controls the volume expansion unit 13, that is, the on-off valve 131 and the volume expansion means 132.

  Here, the recording head 15 mounted on the ink jet recording apparatus 1 will be described with reference to FIGS. 3 is a cross-sectional view of an ink jet recording head that is an example of the liquid jet head according to the first embodiment of the present invention, and FIG. 4 is a cross-sectional view of the main part of the head body.

  As shown in FIG. 3, the head body 20 constituting the recording head 15 of the present embodiment includes a discharge unit 30 that ejects ink droplets and a flow path member 40 that supplies ink to the discharge unit 30.

  As shown in FIG. 4, the discharge unit 30 includes an actuator unit 31, a case 32 that can accommodate the actuator unit 31 therein, a flow path unit 33 joined to one surface of the case 32, and the other surface of the case 32. And a wiring board 34 fixed to the board.

  In the actuator unit 31 of the present embodiment, a piezoelectric actuator forming member 311 in which a plurality of piezoelectric actuators 310 are arranged in parallel along the direction in which the nozzle openings 334 are arranged, and the tip (one end) side of the piezoelectric actuator forming member 311 are free. The base plate (the other end) side has a fixed plate 312 joined as a fixed end so as to be an end.

  The piezoelectric actuator forming member 311 is formed by laminating the piezoelectric material 313 and the electrode forming materials 314 and 315 alternately.

  In the piezoelectric actuator forming member 311, a plurality of slits 316 are formed by, for example, a wire saw or the like, and the piezoelectric actuator 310 is arranged in parallel by cutting the tip end side into a comb-like shape. In the present embodiment, the direction in which the piezoelectric actuators 310 are juxtaposed is the direction in which the nozzle openings 334 are juxtaposed, and is arranged so as to be in the first direction X when mounted in the ink jet recording apparatus 1 described above. The Therefore, hereinafter, the direction in which the nozzle openings 334 are arranged side by side is referred to as a first direction X, and the direction orthogonal to the first direction X is referred to as a second direction Y as in the ink jet recording apparatus 1. Of course, when the head body 20 is mounted on the ink jet recording apparatus 1, the direction in which the nozzle openings 334 are arranged in parallel does not have to coincide with the first direction X, and is not particularly limited. In the present embodiment, a direction orthogonal to both the first direction X and the second direction Y is referred to as a third direction Z.

  Here, the region joined to the fixed plate 312 of the piezoelectric actuator 310 is an inactive region that does not contribute to vibration, and when a voltage is applied between the electrode forming materials 314 and 315 constituting the piezoelectric actuator 310, the fixed plate Only the region on the tip side that is not joined to 312 vibrates. And the front end surface of the piezoelectric actuator 310 is fixed to the diaphragm 331 mentioned later.

  Each piezoelectric actuator 310 of the actuator unit 31 is connected to a circuit board 318 such as a COF on which a drive circuit 317 such as a drive IC for driving the piezoelectric actuator 310 is mounted.

  The flow path unit 33 includes a flow path forming substrate 330, a vibration plate 331, and a nozzle plate 332.

  A plurality of pressure generation chambers 333 are arranged in parallel on the flow path forming substrate 330, and a nozzle plate 332 having a nozzle opening 334 corresponding to each pressure generation chamber 333 and a vibration plate 331 on both sides of the flow path forming substrate 330. And is sealed. The flow path forming substrate 330 is formed with a manifold 336 that communicates with each pressure generation chamber 333 via an ink supply path 335 and serves as a common ink chamber for the plurality of pressure generation chambers 333 for each column. .

  In addition, the tip of the piezoelectric actuator 310 is fixed to a region of the diaphragm of the flow path forming substrate 330 facing each pressure generation chamber 333.

  A compliance portion 337 is provided in a region corresponding to the manifold 336 of the vibration plate 331. The compliance portion 337 plays a role of absorbing the pressure change when the pressure change occurs in the manifold 336 and deforming the compliance portion 337 to keep the pressure in the manifold 336 constant.

  The case 32 is joined to the flow path unit 33 and provided with an ink introduction path 321 for supplying ink from the pressure regulating valve 50 connected to the ink tank 8 to the manifold 336. In the present embodiment, a total of two ink introduction paths 321 are provided, one for each manifold 336. The ink supplied from the ink tank 8 to the ink introduction path 321 via the pressure adjustment valve 50 is supplied to the manifold 336 and distributed to each pressure generation chamber 333 via the ink supply path 335.

  The case 32 is provided with an accommodating portion 322 corresponding to the pressure generating chamber 333. The actuator unit 31 is fixed in the housing portion 322.

  Further, a wiring board 34 is provided on the opposite side of the case 32 from the flow path unit 33, and the other end of the circuit board 318 having one end connected to the actuator unit 31 is connected to the wiring board 34. .

  In such a discharge unit 30, the volume of each pressure generation chamber 333 is changed by deformation of the piezoelectric actuator 310 and the vibration plate 331, and ink droplets are discharged from a predetermined nozzle opening 334.

  In addition, as shown in FIG. 3, the flow path member 40 has a pressure regulating valve 50 fixed on one side and supplies ink from the pressure regulating valve 50 to the ejection unit 30 fixed on the other side. .

  Specifically, the flow path member 40 is provided with an ink communication path 41, and a filter 42 that removes foreign matters such as dust and bubbles contained in the ink is formed on one surface where the ink communication path 41 opens. A supply needle 43 provided on the filter 42 is provided.

  The supply needle 43 is inserted into a pressure adjusting valve 50 described later in detail. Ink from the pressure adjusting valve 50 passes through the inside of the supply needle 43 and is removed from the foreign matter by the filter 42, and then supplied to the ejection unit 30 via the ink communication path 41.

  The pressure regulating valve 50 connected to the flow path member 40 and supplying ink from the ink tank to the recording head will be further described with reference to FIGS. 5 and 6 are enlarged cross-sectional views of the main part of the pressure regulating valve.

  In the present embodiment, as shown in FIG. 3, since one type of ink is supplied to one head main body 20, one pressure adjusting valve 50 is fixed to the flow path member 40. In the present embodiment, each direction of the flow path member 40 is based on the direction when the ink jet recording apparatus 1 is mounted, that is, the first direction X, the second direction Y, and the third direction Z. I will explain. Of course, the arrangement of the flow path member 40 in the ink jet recording apparatus 1 is not limited to the following.

  As shown in FIGS. 3, 5, and 6, each pressure regulating valve 50 is a valve that is provided in the middle of a flow path for ink to open and close the flow path. Specifically, the pressure regulating valve 50 of this embodiment includes a housing 51 and a valve body 55 provided in the housing 51.

  The housing 51 communicates with an ink tank 8 serving as a liquid storage unit via a supply pipe 10 and a primary chamber 511 to which ink is supplied from the ink tank 8 and an ink communication path 41 of the head body 20. A secondary chamber 512 is provided. The primary chamber 511 and the secondary chamber 512 are separated by a partition wall 513. The primary chamber 511 and the secondary chamber 512 communicate with each other via a communication channel 514 provided through the partition wall 513.

  The primary chamber 511 is formed by sealing a recess formed on one surface of the housing 51 with a lid member 515. In addition, one end of an inflow passage 516 is provided in the primary chamber 511 so as to communicate therewith. The ink tank 8 is connected to the other end of the inflow path 516 through the supply pipe 10.

  The secondary chamber 512 has a concave shape that opens on the side surface of the housing 51 opposite to the primary chamber 511. In addition, a film 517 that is a pressure-receiving film body is attached to a surface of the housing 51 where the secondary chamber 512 opens, and the opening of the secondary chamber 512 is sealed with the film 517. Further, one end of the outflow passage 518 communicates with the secondary chamber 512, and a seal member 519 is provided at the other end of the outflow passage 518 opposite to the one end communicating with the secondary chamber 512. Yes. The supply needle 43 of the flow path member 40 is inserted into the seal member 519 and connected to the outflow path 518.

  Here, the film 517 which is a pressure receiving film body can use a flexible material having resistance to the liquid (ink) supplied to the secondary chamber 512. In addition, as the film 517, it is preferable to use a material having low moisture permeability and gas permeability such as oxygen and nitrogen. Examples of the material of the film 517 include a configuration in which a nylon film coated with vinylidene chloride (saran) is bonded and laminated to a high-density polyethylene film or a polypropylene (PP) film. Moreover, you may use a polyethylene terephthalate (PET) etc. as another material. The bonding method of the film 517 is not particularly limited, and heat welding, vibration welding, adhesion with an adhesive, or the like can be used.

  The part which comprises a part of wall surface of the secondary chamber 512 of such a film 517 becomes the diaphragm 517a. A pressure receiving plate 520 is provided on the surface of the diaphragm 517a on the secondary chamber 512 side. The pressure receiving plate 520 of the present embodiment has a disk shape having an outer shape smaller than that of the diaphragm 517a. Such a pressure receiving plate 520 is provided in order to prevent the valve body 55 that opens and closes the communication flow path 514 from directly contacting the film 517, and is made of a material having higher rigidity than the film 517, such as resin or Metal or the like can be used. In this embodiment, the pressure receiving plate 520 has an outer shape smaller than that of the diaphragm 517 a, but is not particularly limited thereto, and one end of the pressure receiving plate 520 is fixed between the film 517 and the housing 51 outside the secondary chamber 512. May be.

  The secondary chamber 512 penetrates in the bottom surface of the secondary chamber 512, that is, in the partition wall 513 facing the diaphragm 517 a of the housing 51 in the thickness direction that is the direction in which the primary chamber 511 and the secondary chamber 512 are partitioned. A communication channel 514 that communicates with the primary chamber 511 is provided. Ink from the primary chamber 511 flows into the secondary chamber 512 via the communication channel 514.

  Since the housing 51 has a complicated shape including the primary chamber 511, the secondary chamber 512, the communication channel 514, and the like, the resin material can be easily formed at low cost by molding. Of course, the material of the housing 51 is not limited to a resin material, and for example, a metal material, a ceramic material, or the like can be used. The housing 51 is formed of a material having higher rigidity than the film 517. Incidentally, if the rigidity of the housing 51 is low, for example, the shape of the secondary chamber 512 is not stable, the pressure difference between the ink pressure in the secondary chamber 512 and the atmospheric pressure outside the film 517 is not stable, and the valve body There is a possibility that the opening and closing operation of the communication channel 514 by 55 cannot be performed stably. Further, the shape of the communication channel 514 may not be stable, and the communication channel 514 may not be normally closed. Therefore, the housing 51 is preferably formed of a material having a certain degree of rigidity.

  The periphery of the opening on the primary chamber 511 side of the partition wall 513 provided with the communication channel 514 of the housing 51 is a valve seat with which the valve body 55 abuts.

  Further, the valve body 55 is inserted through the communication flow path 514 of the housing 51. The valve body 55 includes a shaft body 551 inserted into the communication channel 514 and a valve body main body 550 having a flange portion 552 provided at an end portion in the primary chamber 511 of the shaft section 551, and a flange of the valve body main body 550. A contact member 560 fixed to the portion 552.

  The shaft portion 551 of the valve body 550 has an outer diameter slightly smaller than the communication channel 514 of the housing 51, and one end portion in the secondary chamber 512 abuts on the central portion of the pressure receiving plate 520. Further, the other end of the shaft portion 551 opposite to the one end that contacts the pressure receiving plate 520 is disposed in the primary chamber 511, and the flange portion 552 is disposed at the other end in the primary chamber 511. Are integrally formed. Such a valve body 550 is movable along the first direction X, which is the axial direction of the shaft portion 551. That is, the moving direction of the valve body 55 is the first direction X.

  The flange portion 552 is made of a circular plate member. A contact member 560 is fixed to the flange portion 552. The contact member 560 is made of an elastic material such as rubber or elastomer, and has an annular shape provided continuously around the periphery of the shaft portion 551. Further, the contact member 560 has a shape in which a tip protrudes toward the valve seat. Specifically, the contact member 560 is continuously provided on the valve seat side surface of the flange portion 552 over the periphery of the shaft portion 551, and the thickness of the contact member 560 in the radial direction of the shaft portion 551. The blade has a shape that gradually decreases toward the valve seat side. That is, the radial cross-sectional shape of the contact member 560 has a substantially triangular shape, and the apex of the triangular shape is provided opposite to the valve seat.

  In this embodiment, the contact member 560 is fixed to the flange portion 552. However, the present invention is not limited to this. For example, the contact member 560 is formed in a shape that covers the flange portion 552, and the flange You may make it fit in the part 552. FIG. Further, the valve body 550 and the contact member 560 may be integrated by, for example, integral molding. Thus, by integrating the valve body main body 550 and the contact member 560 by integral molding, it is possible to attach the contact member 560 in a state of being displaced or biased when the contact member 560 is attached to the valve body main body 550. While being able to suppress, the position shift by the contact member 560 contact | abutting repeatedly to a valve seat can be suppressed. Accordingly, the contact member 560 and the valve seat can be stably contacted to improve the sealing performance.

  Further, a coil spring 56 is interposed between the flange portion 552 of the valve body 55 and the lid member 515 that defines the primary chamber 511, and the valve body 55 is pivoted by the biasing force of the coil spring 56. The axial direction of the portion 551 is biased toward the secondary chamber 512 with the moving axis direction as the moving axis direction. That is, the flange portion 552 functions as a spring receiver with which one end of the coil spring 56 abuts.

  Here, the force acting on the valve body 55 includes the reaction force of the film 517, the force acting on the pressure receiving plate 520 and the diaphragm 517a upon receiving the ink pressure in the secondary chamber 512, the biasing force of the coil spring 56, and the supply of ink. There is a force acting on the valve body 55 under pressure.

  The reaction force of the film 517 is a force that the diaphragm 517a that has been bent and deformed tries to restore the original shape. The reaction force of the film 517 increases as the deformation amount of the diaphragm 517a, that is, the deflection amount increases. Such reaction force of the film 517 is transmitted to the shaft portion 551 through the pressure receiving plate 520.

  The force acting on the pressure receiving plate 520 and the diaphragm 517a upon receiving the ink pressure in the secondary chamber 512 is expressed by the product of the pressure receiving area of the pressure receiving plate 520 and the diaphragm 517a receiving the ink pressure and the ink pressure. When the liquid in the secondary chamber 512 is caused to flow downstream from the outflow passage 518 and the ink in the secondary chamber 512 decreases, the differential pressure between the ink pressure and the atmospheric pressure increases, and the pressure receiving plate 520 and the diaphragm 517a The power to work increases. The force acting on the pressure receiving plate 520 and the diaphragm 517a acts as a force in the valve opening direction on the valve body 55 via the shaft portion 551.

  The biasing force of the coil spring 56 is a force that biases the valve body 55 in the valve closing direction. As described above, in this embodiment, the valve body 55 applies a force to the pressure receiving plate 520 opposite to the force acting on the pressure receiving plate 520 and the diaphragm 517 a by the coil spring 56 due to the pressure of the ink in the secondary chamber 512. In order to displace the pressure receiving plate 520 until the valve body 55 reaches the valve opening position, it is necessary to reduce the ink in the secondary chamber 512 to a lower pressure by an amount corresponding to the urging force of the coil spring 56 ( Operating pressure).

  In such a pressure regulating valve 50, as shown in FIG. 5, the ink in the secondary chamber 512 is caused to flow downstream, and the inside of the secondary chamber 512 is reduced to a negative pressure rather than the atmospheric pressure, whereby the diaphragm 517a. Is moved to the bottom surface side of the secondary chamber 512, and the pressure receiving plate 520 presses the valve body 55 against the urging force of the coil spring 56, so that the contact member 560 of the valve body 55 is between the contact member 560 and the contact member 560. A gap is generated, and the communication channel 514 opens, that is, opens (second mode).

  Further, when ink is supplied from the primary chamber 511 to the secondary chamber 512 by this valve opening, and the decompression in the secondary chamber 512 is eliminated, the diaphragm 517a is moved to the coil spring 56 as shown in FIG. The urging force returns to the original position, and the communication flow path 514 is closed by the valve body 55 (first mode).

  Here, the pigment particles contained in the ink accumulate in a minute space formed when the valve body 55 and the valve seat come into contact with each other, and are aggregated by compression and dehydration. Adheres to and accumulates on the valve seat. When the agglomerated ink accumulates on the valve body 55 and the valve seat in this manner, the valve is not reliably closed and ink leakage occurs. Such ink agglomeration often occurs when the contact pressure between the valve body 55 and the valve seat is high. However, if the urging force of the coil spring 56 is weakened, the open / close reactivity decreases and the valve closes. However, the ink may leak.

  Therefore, in this embodiment, the ink jet recording apparatus 1 is provided with the volume expanding unit 13 to expand the volume of the flow path communicating with the primary chamber 511 of the pressure regulating valve 50 to increase the pressure of the ink in the primary chamber 511. The contact pressure between the valve body 55 and the valve seat is reduced.

  Here, the volume expansion unit 13 of this embodiment will be described with reference to FIGS. In addition, FIG. 7 is sectional drawing which shows the outline | summary of the volume expansion means based on Embodiment 1 of this invention.

  As shown in FIG. 2, the volume expansion unit 13 of this embodiment includes an opening / closing valve 131 that is provided in the supply pipe 10 and that opens and closes the supply path, and a volume expansion means 132.

  The on-off valve 131 is provided in the middle of the supply pipe 10 and between the volume expanding means 132 and the ink tank 8, and opens and closes the flow path in the supply pipe 10.

  As shown in FIG. 2, the volume expanding means 132 is provided between the on-off valve 131 and the primary chamber 511 of the pressure regulating valve 50. As shown in FIG. 7, the volume expanding means 132 of this embodiment includes a flow path 133 communicating with the flow path in the supply pipe 10, a pressure adjustment chamber 135 separated by the flow path 133 and the adjustment wall 134, An urging means 136 that is provided in the passage 133 and urges the adjustment wall 134 in the direction in which the volume of the communication flow path expands, and is connected to the pressure adjustment chamber 135 to pump the fluid into the pressure adjustment chamber 135. And a pressure-feeding means 137 such as a pressure pump, and an open / close valve 138 for opening the atmosphere to communicate with the pressure adjusting chamber 135 and the outside.

  The adjustment wall 134 is movably provided in the pressure adjustment chamber 135, and increases and decreases the volume of the flow path 133 by moving the adjustment wall 134. In the present embodiment, the adjustment wall 134 is made of, for example, an elastic material such as rubber or elastomer, or a deformable material such as a film, and can be moved in the pressure adjustment chamber 135 by deformation of the adjustment wall 134. ing. Of course, the adjustment wall 134 is not limited to this. For example, the adjustment wall 134 may be slid and moved in the pressure adjustment chamber 135 by using a plate-like member that hardly elastically deforms as the adjustment wall 134.

  The adjustment wall 134 is urged in a direction in which the volume of the flow path 133 is increased by the urging means 136 provided in the flow path 133. In the present embodiment, a compression coil spring is used as the urging means 136, and one end of the compression coil spring is brought into contact with the inner surface opposite to the adjustment wall 134 of the flow path 133 and the other end is brought into contact with the adjustment wall 134. The urging means 136 urges the adjustment wall 134 in the direction in which the volume of the flow path 133 increases. Of course, the urging means 136 is not limited to this. For example, a tension coil spring may be provided in the pressure adjustment chamber 135 to urge the adjustment wall 134 in the direction in which the volume of the flow path 133 increases. Of course, the biasing means 136 is not limited to a coil spring, and may be a leaf spring or the like.

  The pressure feeding means 137 is for feeding a fluid such as a gas or a liquid into the pressure adjusting chamber 135 and includes a pressurizing pump or the like. By feeding the fluid from the pressure feeding unit 137 into the pressure regulation chamber 135, the regulation wall 134 can be moved in a direction in which the volume of the flow path 133 decreases against the biasing force of the biasing unit 136.

  The open / close valve 138 for opening the atmosphere is a valve device that opens and closes the connection between the pressure adjustment chamber 135 and the outside, and opens the pressure adjustment chamber 135 to the atmosphere by communicating the pressure adjustment chamber 135 with the outside.

  As shown in FIG. 7A, such a volume expanding means 132 feeds fluid into the pressure regulation chamber 135 by the pressure feeding means 137 with the open / close valve 138 for opening the atmosphere closed, thereby adjusting the wall 134. Is moved against the urging force of the urging means 136 to reduce the volume of the flow path 133.

  Further, as shown in FIG. 7 (b), the pumping of the fluid by the pumping means 137 is stopped, and the pressure adjusting chamber 135 is opened to the atmosphere by the opening / closing valve 138 for opening the atmosphere, so that the adjusting wall 134 of the biasing means 136 is removed. The volume of the flow path 133 is increased by moving toward the pressure adjustment chamber 135 by the urging force.

  Such volume expanding means 132 reduces the volume of the flow path 133 in advance as shown in FIG. 7A, and the volume of the flow path 133 as shown in FIG. 7B at a desired timing. Increase. Further, when increasing the volume of the flow path 133 in this way, the supply pipe 10 is closed by the on-off valve 131. Thereby, the pressure of the ink in the primary chamber 511 of the pressure regulating valve 50 of the recording head 15 can be reduced by the negative pressure generated by expanding the volume of the flow path 133.

  That is, the volume expansion of the flow path 133 communicating with the primary chamber 511 by the volume expansion unit 13 is performed after the ink ejection by the recording head 15 is completed, that is, the ink from the ink tank 8 to the recording head 15. This is done after the supply is stopped. That is, when the supply of ink from the ink tank 8 to the recording head 15 is stopped, the pressure adjustment valve 50 is closed as shown in FIG. The volume expansion unit 13 expands the volume of the flow path upstream of the pressure adjustment valve 50. As a result, as shown in FIG. 8, the pressure of the ink in the primary chamber 511 is made lower than that in the first mode, so that the contact pressure between the valve body 55 and the valve seat is lower than that in the first mode. Can also be reduced (third mode). Therefore, it is possible to suppress ink aggregation in the region where the valve body 55 and the valve seat abut. That is, by performing the third mode after the first mode, the time in which the valve body 55 and the valve seat in the first mode contact with high pressure is shortened, and the valve body with the relatively weak pressure in the third mode. The time for which 55 and the valve seat abut against each other can be lengthened. Therefore, it is possible to suppress the accumulation due to the aggregation of the ink and to prevent the ink from leaking due to the generation of a gap when the valve body 55 and the valve seat come into contact with each other due to the deposit. In the present embodiment, the contact pressure between the valve element 55 and the valve seat in the third mode can be reduced by the volume expansion unit 13 without weakening the biasing force of the coil spring 56. It is possible to suppress the decrease in reactivity due to the decrease in ink and the occurrence of ink leakage. In addition, since the valve body 55 and the valve seat are in the third mode after changing from the second mode to the first mode, the valve body 55 and the valve seat are reliably in contact with each other in the first mode. Even in the third mode, ink leakage hardly occurs. The volume of the flow path 133 by the volume expansion unit 13 needs to be increased to the extent that the valve body 55 does not open the communication flow path 514. That is, if the volume of the flow path 133 is excessively increased, the pressure in the primary chamber 511 is excessively decreased, and the valve body 55 may be separated from the valve seat.

  The volume expansion by the volume expansion unit 13 is controlled by the control device 14 mounted on the ink jet recording apparatus 1. Here, the control device 14 which is a control means mounted on the recording apparatus of the present embodiment will be described. FIG. 9 is a block diagram showing a control configuration of the recording apparatus.

  As shown in FIG. 9, the control device 14 includes a print control circuit 141, a recording head drive circuit 142, a print position control circuit 143, and a volume expansion control circuit 144.

  The print control circuit 141 supplies a drive pulse to the print head 15 via the print head drive circuit 142 based on a print signal input from the outside, and controls ejection of ink from the print head 15.

  The print position control circuit 143 controls the relative positions of the recording head 15 in the first direction X and the second direction Y by controlling the carriage motor 7 and a paper feed mechanism (not shown in FIG. 1). To do.

  The volume expansion control circuit 144 controls the operation of the volume expansion unit 13, that is, the on-off valve 131 and the volume expansion means 132, and expands the volume of the flow path 133 that is the flow path on the upstream side of the recording head 15, so The pressure in the primary chamber 511 of the 15 pressure regulating valves 50 is reduced and controlled to the third mode. The control of the volume expansion unit 13 by the volume expansion control circuit 144 is performed when printing by the print control circuit 141 is stopped. Note that the control device 14 further includes, for example, a clock unit that measures an elapsed time after the ejection of ink from the recording head 15 is completed, for example, and the volume expansion control circuit 144 includes a time measured by the clock unit. The volume expansion unit 13 may be controlled based on time to switch from the first mode to the third mode. That is, the time from the first mode to the second mode to supply the ink of the recording head 15 as compared to the time from the third mode to the second mode to supply the ink to the recording head 15. If the printing stop time is short, the mode is directly shifted from the first mode to the second mode if the first mode is switched to the third mode only when the elapsed time is longer. And printing can be started in a short time.

  Further, the volume expansion control circuit 144 may shift from the first mode to the third mode when the recording head 15 moves to the home position area, for example. In order to detect the movement to the home position area, for example, it may be based on the control of the printing position control circuit 143, and it is pressed by moving the recording head 15 or the carriage 5 to the home position area. A switch or the like may be used.

(Other embodiments)
As mentioned above, although one Embodiment of this invention was described, the basic composition of this invention is not limited to what was mentioned above.

  For example, in the first embodiment described above, the on-off valve 131 and the volume expanding unit 132 are provided as the volume expanding unit 13, but the volume expanding unit 132 is not limited to the above. Here, another example of the volume expanding means is shown in FIG. In addition, FIG. 10 is sectional drawing of the volume expansion means based on other embodiment of this invention.

  As shown in FIG. 10, the volume enlarging means 132 </ b> A includes a flow path 133 and a pressure adjustment chamber 135 connected to the ink tank 8, an adjustment wall 134 that separates the flow path 133 and the pressure adjustment chamber 135, and an adjustment wall 134. And a suction means 139 connected to the pressure adjustment chamber 135. Note that the on-off valve 131 of the first embodiment described above is provided between the ink tank 8 and the flow path 133 and the pressure adjustment chamber 135.

  The flow path 133 is connected to the primary chamber 511 of the pressure adjustment valve 50 of the recording head 15, and supplies ink from the ink tank 8 to the recording head 15.

  The pressure adjustment chamber 135 has one end connected to the ink tank 8 and the other end connected to the suction unit 139. Examples of the suction unit 139 include a suction pump. The suction unit 139 may be, for example, a suction pump provided in the maintenance unit 11 and connected to the cap 12.

  The adjustment wall 134 is formed of, for example, an elastic material such as rubber or elastomer, or a deformable material such as a film, and can be moved in the pressure adjustment chamber 135 by the deformation of the adjustment wall 134.

  The urging means 136 urges the adjustment wall 134 toward the flow path 133, and a compression coil spring is used in this embodiment.

  In the volume expanding means 132A having such a configuration, as shown in FIG. 10A, the ink in the pressure adjusting chamber 135 is not sucked by the suction means 139 during printing. Thereby, the adjustment wall 134 moves to the flow path 133 side by the urging force of the urging means 136. When the printing is stopped, as shown in FIG. 10B, the adjustment wall 134 is resisted against the urging force of the urging means 136 by sucking the ink in the pressure adjusting chamber 135 by the suction means 139. Then, it is moved into the pressure adjusting chamber 135 to enlarge the volume of the flow path 133. As a result, the pressure of the ink in the primary chamber 511 of the pressure regulating valve 50 communicating with the flow path 133 is reduced, the pressure of contact between the valve body 55 and the valve seat is reduced, and the ink is condensed and accumulated. Can be suppressed. Although not particularly illustrated, as shown in FIG. 10B, when the volume of the flow path 133 is expanded, the flow path 133 and the upstream of the pressure adjustment chamber 135 are the same as in the first embodiment. In this case, the on-off valve 131 may be closed so that the supply of ink from the ink tank 8 is stopped.

  In the example described above, the volume expanding means 132 and 132A are provided in the middle of the supply pipe 10. However, the present invention is not limited to this. For example, the volume expanding means 132 and 132A are integrated with the pressure regulating valve 50. It may be provided. That is, the flow path 133 of the volume expanding means 132 may be the primary chamber 511.

  Further, although not particularly mentioned in the above-described first embodiment, a region where the contact member 560 and the valve seat contact each other may be subjected to a liquid repellent treatment. Thereby, the deposit in the area | region where the contact member 560 and a valve seat contact | abut mutually can be suppressed.

  In the first embodiment described above, the piezoelectric actuator 310 that extends and contracts in the axial direction by alternately stacking the piezoelectric materials 313 and the electrode forming materials 314 and 315 as pressure generating means for causing a pressure change in the pressure generating chamber 333 is provided. As described above, the pressure generating means is not particularly limited. For example, the pressure generating means is formed by a method of forming a thin film type in which an electrode and a piezoelectric material are laminated by a lithography method and attaching a green sheet. A flexural vibration type piezoelectric actuator such as a thick film type can be used. Also, as a pressure generating means, a heating element is arranged in the pressure generating chamber, and droplets are discharged from the nozzle opening by bubbles generated by the heat generated by the heating element, or static electricity is generated between the diaphragm and the electrode. Thus, a so-called electrostatic actuator that discharges liquid droplets from the nozzle openings by deforming the diaphragm by electrostatic force can be used.

  In the ink jet recording apparatus 1 described above, the recording head 15 is mounted on the carriage 5 and moves in the first direction X. However, the present invention is not particularly limited thereto, and for example, the recording head 15 is fixed. Thus, the present invention can also be applied to a so-called line type recording apparatus that performs printing only by moving the ejection target medium in the second direction Y.

  In the above-described example, the ink jet recording apparatus 1 has a configuration in which the ink tank 8 which is a liquid storage unit is mounted on the tank holder 9 of the main body frame 2, but is not particularly limited thereto. A certain ink cartridge may be mounted on the carriage 5. The pressure adjustment valve 50 is not limited to the one mounted on the carriage 5, and the pressure adjustment valve 50 and the recording head 15 may be connected via a supply pipe such as a tube.

  Furthermore, the present invention is intended for a wide range of liquid ejecting apparatuses having a wide liquid ejecting head. For example, recording heads such as various ink jet recording heads used in image recording apparatuses such as printers, liquid crystal displays, and the like Liquid comprising a color material ejecting head used for manufacturing a color filter, an electrode material ejecting head used for forming an electrode such as an organic EL display and an FED (field emission display), a bioorganic matter ejecting head used for biochip manufacturing, etc. It can be used for an injection device.

  DESCRIPTION OF SYMBOLS 1 Inkjet recording apparatus (liquid ejecting apparatus), 2 Main body frame (apparatus main body), 3 Medium support member, 4 Guide shaft, 5 Carriage, 6 Timing belt, 7 Carriage motor, 8 Ink tank (liquid storage means), 9 Tank Holder, 10 Supply pipe, 11 Maintenance unit, 12 Cap, 13 Volume expansion unit, 14 Control device, 15 Inkjet recording head (liquid ejecting head), 20 Head body, 30 Discharge unit, 31 Actuator unit, 32 Case, 33 Flow Path unit, 34 wiring board, 40 flow path member, 50 pressure regulating valve, 51 housing, 55 valve body, 56 coil spring, 131 on-off valve (open / close means), 132, 132A volume expanding means, 133 flow path, 13 Adjusting wall, 135 pressure adjusting chamber, 136 biasing means, 137 pressure feeding means, 138 open / close valve for opening to atmosphere, 139 suction means, 310 piezoelectric actuator (pressure generating means), 321 ink introduction path, 331 diaphragm, 332 nozzle plate, 333 Pressure generating chamber, 334 Nozzle opening, 335 Ink supply path, 336 Manifold, 511 Primary chamber, 512 Secondary chamber, 513 Partition, 514 Communication channel, 515 Cover member, 516 Inflow path, 517 Film (pressure receiving film body) , 517a Diaphragm, 518 Outflow passage, 519 Seal member, 520 Pressure receiving plate, 550 Valve body, 551 Shaft, 552 Flange, 560 Contact member

Claims (3)

A primary chamber connected to a liquid storage means storing a liquid via a supply path; a secondary chamber separated from the primary chamber by a partition; and a communication channel provided through the partition; A valve body that opens and closes the communication flow path in contact with and away from the valve seat, with a surface on the primary chamber side of the partition wall where the communication flow path opens as a valve seat; and an opening of the secondary chamber And a pressure receiving valve body that opens and closes the valve body on the basis of atmospheric pressure, and a liquid is supplied from the secondary chamber of the pressure adjusting valve and the supplied liquid A liquid ejecting apparatus comprising: a head body that ejects from a nozzle opening; and an opening / closing means that is provided between the liquid storage means and the primary chamber, and that opens and closes the supply path, and the opening / closing means And in the flow path including the primary chamber between the primary chamber and the primary chamber, Comprising the volume increasing means for increasing the volume of the road, and
A first mode in which the valve body is in contact with the valve seat and the communication channel is closed;
A second mode in which the valve body is separated from the valve seat to open the communication channel;
Control means capable of switching between a third mode in which the opening and closing means closes the supply path and the volume expanding means expands the volume of the flow path,
The liquid ejecting apparatus according to claim 1, wherein the control unit switches from the first mode to the third mode after the liquid is ejected by the head body. The volume expanding means is
A pressure adjusting chamber separated by the flow path and the adjusting wall;
Pressure feeding means connected to the pressure regulation chamber and feeding fluid to the pressure regulation chamber,
The adjustment wall is movably provided in the pressure adjustment chamber,
The adjustment wall is urged by an urging means in a direction to increase the volume of the flow path in the pressure adjustment chamber,
2. The volume expansion means increases the volume of the flow path by the urging force of the urging means by stopping the pressure feeding of the fluid to the pressure adjusting chamber by the pressure feeding means. The liquid ejecting apparatus described. The control means includes a clock means for measuring an elapsed time after the ejection of liquid from the head body is completed,
The liquid ejecting apparatus according to claim 1, wherein the control unit switches from the first mode to the third mode based on an elapsed time measured by the clock unit.

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