JP2014193555A - Switching valve unit for backwash, liquid jet head and liquid jet device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a switching valve unit for backwash capable of performing the backwash of a filter disposed in a channel of a recording head in a state that the recording head is mounted on a recording device.SOLUTION: A switching valve unit for backwash has: a channel 17 for circulating ink discharged from a liquid jet head toward a switching chamber 16; a channel 28 for ejecting a cleaning solvent from the switching chamber 16 when performing the backwash; a channel 29 for circulating the ink from the switching chamber 16 toward a channel of the liquid jet head and circulating the cleaning solvent introduced from the channel of the liquid jet head toward the switching chamber 16; and valve bodies 20 and 21 that respectively open/close between the channel 17 and the switching chamber 16 and between the channel 28 and the switching chamber 16, and that are operated so that one of valve bodies is opened when the other is closed.

Description

  The present invention relates to a backwashing switching valve unit, a liquid ejecting head, and a liquid ejecting apparatus, and is particularly useful when applied to cleaning a liquid ejecting head having a foreign matter capturing filter in the middle of a liquid flow path.

  2. Description of the Related Art Conventionally, ink jet recording apparatuses (hereinafter also referred to as “recording apparatuses”) are widely known as liquid ejecting apparatuses that eject liquid onto a target. In this type of recording apparatus, an ink jet liquid ejecting head (hereinafter also referred to as “recording head”) is mounted on a carriage that reciprocates, and an ink cartridge (liquid storage unit) that is mounted on the recording head at a predetermined location. Printing is performed by supplying ink (liquid) from the body and ejecting the ink from a nozzle formed on the nozzle formation surface of the recording head to a recording medium as a target.

  For this reason, in this type of recording apparatus, a valve unit (liquid supply apparatus) having a liquid supply path for supplying ink from the ink cartridge to the recording head is provided on the carriage, and is located in the middle of the liquid supply path in the valve unit. Is provided with a pressure chamber (liquid storage part) capable of temporarily storing ink (see, for example, Patent Document 1). In this valve unit, a filter is interposed in the middle of the liquid supply path on the ink cartridge side (upstream side) from the pressure chamber. In other words, even if foreign matter is contained in the ink flowing from the ink cartridge side into the pressure generating chamber, the filter prevents the foreign matter from flowing into the pressure generating chamber.

In some cases, the filter member is thermally welded to an ink introduction port through which ink supplied from the valve unit side flows into the recording head (see, for example, Patent Document 2).
The recording head used for printing or the like for a certain period of time captures with a filter, and in order to remove the accumulated foreign matter, the cleaning liquid is applied to the recording head in the direction opposite to the flow direction of the ink when discharging from the nozzle side. Some of them are subjected to backwashing (also called backwashing) for cleaning and removing foreign substances accumulated in the filter.

JP 200595861 A JP 2005-199555 A

However, the conventional backwashing of the filter of the recording head has been performed by removing the recording head from the recording apparatus, which requires work such as removing the recording head. So backwashing was a cumbersome task requiring a lot of work time.
Such a problem exists not only in the ink jet recording head but also in a liquid ejecting head that ejects liquid other than ink.

  An object of the present invention is to provide a backwashing switching valve unit, a liquid ejecting head, and a liquid ejecting apparatus that enable easy backwashing of a filter.

An aspect of the present invention that solves the above-described problems includes a first flow path for flowing the liquid discharged from the liquid jet head toward the switching chamber, and a second flow for discharging the cleaning liquid at the time of backwashing from the switching chamber. A third flow path for flowing the liquid from the switching chamber toward the flow path of the liquid ejecting head and for allowing the cleaning liquid introduced from the flow path of the liquid ejecting head to flow toward the switching chamber. Opening and closing between the first flow path and the switching chamber and between the second flow path and the switching chamber, respectively, and operating so that when the one is opened, the other is closed A switching valve unit for backwashing, characterized in that it has a valve body.
According to this aspect, it is possible to easily switch and select between the normal mode (printing mode) and the backwash mode only by moving the valve body in one direction or the opposite direction. Note that the valve body is not limited to one in which one is open but the other is always closed, and includes one in which both are temporarily open during the switching operation.

  Here, the valve body is integrally connected via a rod, and at the same time the first flow path and the switching chamber are communicated with each other by a spring force acting via one valve body. The valve body is opened and closed so that the space between the second flow path and the switching chamber is closed, while the valve body is integrated by pushing the rod against the spring force during backwashing. The valve body is opened and closed so that the second flow path and the switching chamber communicate with each other to be closed, and at the same time, the first flow path and the switching chamber are closed. Can be configured. In this case, it is possible to change or select the backwash mode by applying an external force to the rod and pushing the rod. Furthermore, the operation of pushing the rod can be easily automated as will be described later.

  Further, the valve body is integrally connected through a rod, and at the same time the first flow path and the switching chamber are communicated with each other by a spring force acting through one valve body, While the valve body is opened and closed so that the space between the second flow path and the switching chamber is closed, the difference between the negative pressure of the pump acting on the second flow path and the atmospheric pressure during backwashing By pushing the rod against the spring force with an external force based on the above, the valve body is moved integrally to communicate between the second flow path and the switching chamber, and at the same time, the first flow The valve element can be configured to be opened and closed by closing a path between the passage and the switching chamber. In this case, it is possible to automatically enter the backwash mode simply by driving the pump for sucking the cleaning liquid along with the backwash process.

  Furthermore, it has two valve bodies which are disposed in the switching chamber so as to be movable between the first flow path side and the second flow path side, and the distance between the two is extendable and connected by a spring. In the state where the switching chamber is filled with the liquid, each of the valve bodies moves to the first flow path side and the second flow path side by the spring force of the spring, and the first flow path And between the switching chamber and between the second flow path and the switching chamber, and in a state where the communication state between the second flow path and the switching chamber is blocked, When the liquid is discharged from the switching chamber to the outside through the third flow path, the switching chamber becomes negative pressure, thereby moving the valve body on the first flow path side to the second flow path side. The first flow path and the switching chamber communicate with each other to allow the liquid to be supplied to the switching chamber. Sometimes, the amount of displacement of the rod on the second channel side in the direction from the first channel to the second channel based on the difference between the negative pressure of the pump acting on the second channel and the atmospheric pressure The tip of the rod is moved in the second flow direction by making the displacement larger than the displacement amount of the other rod in the direction on the first flow path side based on the difference between the negative pressure and the atmospheric pressure in the switching chamber. Close the flow path between the first flow path and the switching chamber by moving the valve body toward the first flow path side by contacting the valve body on the road side, and the second flow path It can also comprise so that the flow path between the said switching chambers may be opened. In this case, a so-called self-sealing function during normal printing is ensured. In addition, it is possible to automatically enter the backwash mode only by driving the pump for sucking the cleaning liquid in accordance with the backwash process.

According to another aspect of the invention, there is provided a liquid ejecting head including the backwash switching valve unit.
According to this aspect, the back washing process can be performed without disassembling the liquid jet head.

Another aspect of the invention is a liquid ejecting apparatus including the liquid ejecting head.
According to this aspect, the backwashing cleaning process can be performed without disassembling the liquid jet head, so that the time required for the backwashing process can be dramatically shortened. As a result, it is possible to improve the throughput of the original processing of the liquid ejecting apparatus such as printing.

  Here, when the liquid ejecting head is moved in the non-printing area during the back washing process, the rod is pushed against the spring force by the tip of the rod coming into contact with the fixing portion on the apparatus main body side. Can be configured to gain power. In this case, the preparation for the backwash process is completed simply by moving the liquid jet head to the non-printing area.

  In addition, when the liquid ejecting head is moved to a non-printing area during the backwashing process, the lowering of the nozzle surface is relatively utilized when the liquid ejecting head is attached to the flushing cap. It is also possible to obtain a force for pushing the rod against the spring force by pushing the rod whose tip is in contact with the convex portion upward. In this case, the preparation for the backwash process is completed simply by moving the liquid jet head to the non-printing area.

1 is a schematic perspective view of a recording apparatus according to an embodiment of the present invention. It is sectional drawing of the switching valve unit for backwashing concerning the 1st Embodiment of this invention. It is sectional drawing of the switching valve unit for backwashing concerning the 2nd Embodiment of this invention. It is sectional drawing of the switching valve unit for backwashing concerning the 3rd Embodiment of this invention. It is sectional drawing of the switching valve unit for backwashing based on the 4th Embodiment of this invention. It is sectional drawing of the switching valve unit for backwashing based on the 4th Embodiment of this invention. It is sectional drawing of the switching valve unit for backwashing based on the 4th Embodiment of this invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a schematic perspective view of an ink jet recording apparatus (hereinafter also simply referred to as a recording apparatus) which is an example of a liquid ejecting apparatus according to an embodiment of the present invention. As shown in the figure, an ink jet recording apparatus I according to this embodiment has an ink jet recording head (hereinafter also simply referred to as a recording head) 1, and further includes supply means for supplying ink to the recording head 1. The constituting ink cartridge 2 is detachably provided. A carriage 3 on which the recording head 1 is mounted is provided on a carriage shaft 5 attached to the apparatus main body 4 so as to be movable in the axial direction. The recording head 1 ejects a black ink composition and a color ink composition, respectively. That is, ink, for example, pigment ink, which is a dispersion liquid in which solid particles are dispersed in a liquid, is ejected from a nozzle.

  A drive motor 6 is provided near one end of the carriage shaft 5, and a first pulley 6 a having a groove on the outer periphery is provided at the tip of the shaft of the drive motor 6. Further, a second pulley 6b corresponding to the first pulley 6a of the drive motor 6 is rotatably provided in the vicinity of the other end of the carriage shaft 5, and the first pulley 6a and the second pulley are provided. A timing belt 7 made of an elastic member such as rubber is hung between the belt 6b.

  Then, the driving force of the driving motor 6 is transmitted to the carriage 3 via the timing belt 7, so that the carriage 3 on which the recording head 1 is mounted is moved along the carriage shaft 5 in the main scanning direction. On the other hand, the apparatus body 4 is provided with a platen 8 along the carriage 3. The platen 8 can be rotated by a driving force of a paper feed motor (not shown). A recording sheet S, which is a recording medium such as paper fed by a paper feed roller, is wound around the platen 8 and is sub-scanned. It is transported in the direction.

  A maintenance area for performing maintenance (cleaning) of the nozzle formation surface of the recording head 1 is formed at a home position (HP) provided at a position outside the area where the recording sheet S is conveyed in the apparatus main body 4. In this embodiment, the backwash area 10 is disposed. The backwashing of the filter to be described in detail later is performed in the backwashing area 10.

  Although not shown in FIG. 1, there is a discharge tube for discharging waste liquid generated by backwashing the filter from the recording head 1 in the recording apparatus I of this embodiment to the backwashing area 10. Next, a specific configuration of the backwash switching valve unit will be described in detail as first to fourth embodiments based on the drawings. In the following, the term “negative pressure” is used to mean that the pressure is lower than normal.

<First Embodiment>
FIG. 2 is a cross-sectional view of the backwash switching valve unit according to the first embodiment. FIG. 4A shows an aspect when supplying ink, and FIG. 5B shows an aspect when backwashing. As shown in both figures, the backwashing switching valve unit 11 according to this embodiment has three types of openings, an ink supply port 13, a backwashing port 14, and a connection port 15, formed in the main body 12. . A switching chamber 16, which is a space, is formed at the center of the main body 12. The switching chamber 16 has a flow path 17 communicating with the ink supply port 13, a flow path 28 communicating with the backwash port 14, and a flow path 29 connecting the connection port 15. Yes.

  The switching chamber 16 includes a valve chamber 16A provided on the ink supply port 13 side of the main body 12, a valve chamber 16B provided on the backwash port 14 side, and a communication chamber 16C communicating the valve chambers 16A and 16B. In the valve chambers 16A and 16B, the left and right openings in the figure are closed by film members 18 and 19, which are flexible members. The valve bodies 20 and 21 are connected via a rod 22 and disposed in the valve chambers 16a and 16b, respectively. A spring 23 is interposed at the end of the rod 22 on the valve chamber 16B side. The spring 23 applies a spring force from the valve chamber 16 </ b> B toward the valve chamber 16 </ b> A, and has one end in contact with the valve body 21 and the other end in contact with the film member 19. Therefore, the rod 22 is normally biased toward the valve chamber 16 </ b> A by the spring force of the spring 23.

  Accordingly, during normal operation (when ink is supplied), as shown in FIG. 2A, the valve body 20 moves to the left side in the drawing to open the space between the valve chamber 16A and the communication chamber 16C, and The body 21 integrally moves to the left in the figure to close the space between the valve chamber 16B and the communication chamber 16C. At this time, the tip of the rod 22 penetrates the film member 18 and protrudes greatly to the outside. This is the ink supply mode, in which the valve body 20 is opened and the valve body 21 is closed.

  On the other hand, when the tip of the rod 22 comes into contact with something and the rod 22 moves toward the valve chamber 16B against the spring force of the spring 23, as shown in FIG. The valve chamber 16B and the communication chamber 16C are opened by moving to the right side in the drawing, and the valve body 20 is integrally moved to the right side in the drawing to close the space between the valve chamber 16A and the communication chamber 16C. To do. This is the backwash mode, in which the valve body 20 is closed and the valve body 21 is opened. Here, when the recording head 1 is transferred to the backwash area 10 together with the carriage 3 during backwashing in FIG. 1, the force for pressing the rod 22 toward the valve chamber 16B is reversed as shown in FIG. What is necessary is just to comprise so that the front-end | tip of the rod 22 may contact | abut to protrusion 10A of the washing area 10. FIG.

  In this embodiment, the backwashing switching valve unit 11 is set to the state shown in FIG. 2A at the normal time when ink is supplied to the recording head 1 (see FIG. 1; the same applies hereinafter). In this case, the ink from the ink cartridge 2 flows through the ink supply port 13 as indicated by the arrow A1 in FIG. 2A, and is supplied to the recording head 1 communicating with the connection port 15. Is done.

  On the other hand, when the filter is backwashed, the backwashing switching valve unit 11 is set to the state shown in FIG. 2B so that the nozzles of the recording head 1 are immersed in the cleaning liquid. In this case, the cleaning liquid drawn in from the nozzles of the recording head 1 and back-filtered by drawing the cleaning liquid with the pump 100 in the backwash area 10 is indicated by an arrow A2 in FIG. By flowing as shown, the cleaning solution for cleaning the filter is discharged to the backwash area 10 via the backwash port 14 and the discharge tube, and a predetermined backwash process is performed.

<Second Embodiment>
FIG. 3 is a cross-sectional view of the switching valve unit for backwashing according to the second embodiment. FIG. 4A shows an aspect when supplying ink, and FIG. 5B shows an aspect when backwashing. As shown in both figures, the backwashing switching valve unit 31 according to this embodiment has three types of openings, an ink supply port 33, a backwashing port 34, and a connection port 35, formed in the main body 32. . A switching chamber 36 that is a space is formed in the center of the main body 32. A flow path 37 communicating with the ink supply port 33 and a flow path 38 communicating with the backwashing port 34 are opened in the switching chamber 36, and a valve is formed between each flow path 37, 38. The body 40, 41 is configured to open and close. 3A, the valve body 40 is open and the valve body 41 is closed. In FIG. 3B, the valve body 40 is closed and the valve body 41 is open.

  The leaf spring 48 formed of a flexible plate material has a proximal end portion fixed to the main body 32 in the vicinity of the connection port 35 and a valve body 41 fixed to the distal end portion. The lower end of the rod 42 is fixed to the central portion of the film member 49 that is a flexible member that is formed and closes the lower end opening of the switching chamber 36 via the valve body 40. The upper end of the rod 42 is fixed halfway between the base end portion and the tip end portion of the leaf spring 48. As a result, in the state of FIG. 3A, the valve element 41 is pressed in the same direction by the spring force of the leaf spring 48 toward the lower side in the drawing, and the space between the flow path 38 is closed. At the same time, the valve element 40 is pressed in the same direction by the spring force of the leaf spring 48 through the rod 42 and downward in the figure to open the passage 37. This is a normal state in which ink is supplied from the ink cartridge 2 to the recording head 1.

  On the other hand, when the rod 42 is pushed upward in the drawing against the spring force of the leaf spring 48 and the valve body 40 is closed by contacting the main body 32, it is fixed to the tip of the leaf spring 48 pushed up by the rod 42 at the same time. The valve body 41 thus moved also moves upward in the figure to open a space between the flow path 38. This is a state of backwashing in which the filter 44 is washed with the washing liquid sucked from the recording head 1 by driving the pump 100 and then discharged to the outside through the flow path 38 and the backwashing port 34. Here, the flow path 38 extends horizontally from the main body 32 in the direction of the back side of the page, and further communicates with the backwash port 34 by changing the direction upward.

  The backwash switching valve unit 31 is integrated with the head main body 1 </ b> A via the flow path member 1 </ b> B of the recording head 1. Here, the flow path 45 of the flow path member 1B in which the filter 44 to be backwashed is disposed communicates with the inside of the recording head main body 1A. The flow path 45 communicates with the switching chamber 36 via the connection port 35.

  The recording head 1 is attached to the cap 43 for flushing during maintenance (a head cleaning method for forcibly ejecting ink from the recording head 1 via the nozzle 1AA). In this embodiment, the recording head 1 is attached to the cap 43. Backwashing was also performed with the recording head 1 mounted. Therefore, the cap 43 is formed with a convex portion 43A whose upper end is in contact with the rod 42 via the film member 49. In FIG. 3A, the convex portion 43A that is not in contact with the film member 49 is formed. When the recording head 1 is pushed into and attached to the cap 43, the tip of the convex portion 43A comes into contact with the lower surface of the film member 49 as shown in FIG. This pushes the rod 42 upward in the figure. Thus, the backwash mode shown in FIG.

  In this embodiment, at the normal time when ink is supplied to the recording head 1, the backwash switching valve unit 31 is set to the state shown in FIG. In this case, the ink from the ink cartridge 2 flows through the ink supply port 33 as shown by the arrow B1 in FIG. 3A, thereby supplying the recording head 1 communicating with the connection port 35. Is done.

  On the other hand, when the filter 44 is backwashed, the backwashing switching valve unit 31 is set to the state shown in FIG. 3B so that the nozzle 1AA of the recording head 1 is immersed in the cleaning liquid. In this case, the cleaning liquid drawn in from the nozzles of the recording head 1 and back cleaned by drawing the cleaning liquid with the pump 100 in the backwash area 10 is indicated by the arrow B2 in FIG. By flowing as shown, the cleaning liquid for cleaning the filter is discharged to the backwash area 10 via the backwash port 34 and the discharge tube, and a predetermined backwash process is performed.

<Third Embodiment>
FIG. 4 is a cross-sectional view of the switching valve unit for backwashing according to the third embodiment. FIG. 4A shows an aspect when supplying ink, and FIG. 5B shows an aspect when backwashing. As shown in both figures, the backwashing switching valve unit 51 according to the present embodiment has three types of openings, an ink supply port 53, a backwashing port 54, and a connection port 55, formed in the main body 52. . A switching chamber 56 that is a space is formed in the center of the main body 52. In the case of this embodiment, the switching chamber 56 includes a central space 56A that is a large space formed in the central portion of the main body 52, and communication chambers 56B and 56C that are symmetrically disposed on both sides of the central space 56A. Here, a flow path 57 communicating with the ink supply port 53 is opened in the communication chamber 56B, and a flow path 68 communicating with the backwashing port 54 is opened in the communication chamber 56C. The outer peripheral side is closed by film members 58 and 59 which are flexible members. The left and right ends of the rod 62 are fixed to the inner surfaces of the film members 58 and 59. The rod 62 is disposed through the communication chamber 56B, the central space 56A, and the communication chamber 56C, and the valve body 60 is fixed in the central space 56A. An opening / closing pad 60A for opening / closing the communication chamber 56B and an opening / closing pad 60B for opening / closing the communication chamber 56C are fixed to both left and right ends of the valve body 60. A spring 63 through which the rod 62 passes is interposed between the end face of the valve body 60 on the communication chamber 56B side and the main body 52. That is, one end of the spring 63 is in contact with the end surface of the valve body 60 on the communication chamber 56 </ b> B side, and the other end is in contact with the main body 52. In this state, the spring 63 presses the valve body 60 and the rod 62 toward the communication chamber 56C. As a result, at the normal time shown in FIG. 4A, the valve body 60 is pressed toward the communication chamber 56C by the spring force of the spring 63, so that the opening / closing pad 60B closes the space between the central space 56A and the communication chamber 56C. . Here, the central space 56 </ b> A and the connection port 55 are communicated with each other through a flow path 69, and the backwash switching valve unit 51 can be communicated with the recording head 1 via the flow path 69.

  On the other hand, when pressure is applied to the film member 59 from the outside, the valve body 60 is moved to the communication chamber 56B side via the rod 62 against the spring force of the spring 63. As a result, the opening / closing pad 60B is separated from the main body 52, and the space between the central space 56A and the communication chamber 56C is opened. At the same time, since the opening / closing pad 60A is in contact with the main body 52, the space between the central space 56A and the communication chamber 56B is closed. That is, the state shown in FIG. This is the state during backwashing. In the case of this embodiment, the external force that presses the film member 59 during backwashing uses atmospheric pressure that acts by driving the pump 100 to make the communication chamber 56C a negative pressure.

  In this embodiment, at the normal time of supplying ink to the recording head 1, the backwash switching valve unit 51 is set to the state shown in FIG. In this case, ink from the ink cartridge 2 flows through the ink supply port 53 as shown by an arrow C1 in FIG. 4A, and is supplied to the recording head 1 communicating with the connection port 55. Is done.

  On the other hand, at the time of backwashing of the filter, as described above, the communication chamber 56C becomes negative pressure, and the backwashing switching valve unit 51 is brought into the state of FIG. In this state, when the cleaning liquid is further drawn by the pump 100, the cleaning liquid sucked from the nozzles of the recording head 1 and back-washed the filter flows from the connection port 55 as shown by an arrow C2 in FIG. Thus, the cleaning liquid that has cleaned the filter is discharged to the backwash area 10 via the backwash port 54 and the discharge tube, and a predetermined backwash process is performed.

  As described above, according to the present embodiment, unlike the first and second embodiments, if the pump 100 is driven and a predetermined negative pressure is generated without causing physical contact, the backwash state is switched. be able to.

  In this embodiment, the valve body 60 may of course be formed by fixing two plate members to the rod 62 at a predetermined interval.

<Fourth embodiment>
5-7 is sectional drawing of the switching valve unit for backwashing based on 4th Embodiment. FIG. 5 shows a mode before ejection after ink is supplied to the inkjet head, FIG. 6 shows a mode immediately after ink ejection, and FIG. 7 shows a mode during backwashing. As shown in each drawing, the backwashing switching valve unit 71 according to this embodiment has three types of openings, an ink supply port 73, a backwashing port 74, and a connection port 75, formed in the main body 72. .

  A switching chamber 76 that is a space is formed inside the main body 72. The switching chamber 76 includes three sections: a central portion 76A and communication chambers 76B and 76C formed symmetrically with respect to the central portion 76A. The communication chamber 76B is connected to the central portion 76A by a flow passage 77 that is partitioned by a flange portion 72A that protrudes from the inner peripheral surface of the main body 72 to the central portion and communicates with the ink supply port 73. The communication chamber 76 </ b> C communicates with the central portion 76 </ b> A with a flow path 88 that is partitioned by a flange portion 72 </ b> B protruding from the inner peripheral surface of the main body 72 to the central portion and communicates with the backwash port 74.

  The valve bodies 80 and 81 are made of opposing plate materials and are disposed on both sides of the spring 84 with the spring 84 interposed therebetween. Here, the valve bodies 80 and 81 are biased so as to move in a direction away from each other (the valve body 80 is in the left direction and the valve body 81 is in the right direction). The valve bodies 80 and 81 and the spring 84 are integrated so as to be slidable in the horizontal direction on the slide member 85 while closing the space between the slide member 85 and the main body 72.

  Thus, before the ink is discharged as shown in FIG. 5, the valve bodies 80 and 81 abut against the end surfaces of the flange portions 72A and 72B by the spring force of the spring 84, respectively, thereby closing the space between the central portion 76A and the communication chambers 76B and 76C. doing.

  On the other hand, immediately after the ink is discharged as shown in FIG. 6, the central portion 76A is under negative pressure, so that the film member 78 is deflected due to atmospheric pressure, and the rod 82 is pushed toward the communication chamber 76C. Is moved in the same direction (right direction in the figure), the space between the communication chamber 76B and the central portion 76A is opened. As a result, as indicated by the arrow D1 in the drawing, the ink is filled in the central portion 76A from the ink cartridge 2 through the flow path 77 and the communication chamber 76B. At this time, since the valve body 81 closes the passage leading to the communication chamber 76C, the negative pressure acting on the central portion 76A does not act on the communication chamber 76C, and the film member 79 and the rod 83 are in the state shown in FIG. Is maintained. When the ink filling is completed and the central portion 76A recovers to the atmospheric pressure, the film member 78 and the rod 82 also return to the state shown in FIG.

  At the time of backwashing shown in FIG. 7, the pump 100 of the backwashing switching valve unit 71 in the state of FIG. 5 is driven, and the cleaning liquid is drawn through the nozzles of the recording head 1. As a result, the communication chamber 76C has a negative pressure and the atmospheric pressure acts, whereby the film member 79 is bent inward (the communication chamber 76C side). As a result, the rod 83 and the valve body 81 move to the communication chamber 76B side (left side in the figure), and the space between the communication chamber 76C and the central portion 76A is opened. After that, the cleaning liquid is drawn through the nozzles of the recording head 1 by driving the pump 100. When the cleaning liquid is drawn through the nozzles of the recording head 1, the negative pressure acts on the central portion 76 </ b> A, so that the film member 78 tends to bend inward (to the central portion 76 </ b> A). As a result, the rod 82 tries to move to the communication chamber 76C side (right side in the figure). At this time, by adjusting the force applied to the rod 83 to be larger than the force applied to the rod 82, the valve body 80 is pressed against the end surface of the flange portion 72A, and the valve body 81 is moved to communicate with the central portion 76A. The chamber 76C can be opened to allow both to communicate with each other. Thus, since the space between the central portion 76A and the communication chamber 76C can be opened with the flow path from the central portion 76A to the communication chamber 76B closed, as shown by the arrow D2 in the figure, the backwash port The cleaning liquid that has flowed into the flow path 89 through 74 is discharged into the backwash area 10 through the backwash port 74 and the discharge tube only through the flow path 88.

  As shown in FIG. 7, various configurations for making the force applied to the rod 83 larger than the force applied to the rod 82 are conceivable. For example, the rod 83 is displaced more than the fixing position of the film member 78 of the rod 82. It is conceivable that the film member 79 is fixed to the central portion of the film member 79 in a larger amount. Alternatively, the area of the film member 79 may be larger than the area of the film member 78.

  In this embodiment, since the backwashing switching valve unit 71 also has a self-sealing function, the backwashing switching valve unit 71 is kept in the state shown in FIG. By discharging ink in this state, the space between the central portion 76A, the communication chamber 76B and the flow path 77 is opened by the negative pressure acting on the central portion 76A, and the state shown in FIG. A predetermined amount is supplied to the recording head 1 by flowing as indicated by an arrow D1 in FIG.

  On the other hand, when the filter is backwashed, the cleaning liquid is drawn in by the pump 100, so that the state shown in FIG. 7 is obtained and the cleaning liquid sucked from the nozzle of the recording head 1 and backwashed the filter is as shown by an arrow D2 in FIG. By flowing, the cleaning liquid for cleaning the filter is discharged to the outside, and a predetermined backwashing process is performed.

<Other embodiments>
The backwash switching valve units 11, 31, 51, 71 according to the present invention can be built into the recording head 1 from the beginning or can be mounted later.
Further, the following modifications may be combined, and the structure of the backwash switching valve unit is not limited to the above example, and other structures may be used.

  In the ink jet recording apparatus I described above, the ink jet recording head 1 is mounted on the carriage 3 and moves in the main scanning direction. However, the present invention is not particularly limited thereto. The present invention can also be applied to a so-called line type recording apparatus that is fixed to the apparatus main body 4 and performs printing only by moving a recording sheet S such as paper in the sub-scanning direction.

  Further, in the ink jet recording apparatus I described above, the pump 100 is in the backwash area 10 and the cleaning liquid after the cleaning is also discharged to the backwash area 10, but this is not a limitation. For example, the discharge destination of the pump 100 and the cleaning liquid after cleaning may be on the carriage 3, or may be in a different place from the backwash area 10 outside the carriage 3.

  Further, for example, in the first embodiment, the valve bodies 20 and 21 have high elasticity on the communication chamber 16C side, and the valve body 20 closes the flow path when the rod 22 is pushed. 21 may open the flow path. In other embodiments as well, the other channel may be released after one channel is closed.

  In the above-described example, the ink jet recording head 1 is described as an example of the liquid ejecting head, and the ink jet recording apparatus I is illustrated as an example of the liquid ejecting apparatus. The present invention is intended for the entire apparatus, and can of course be applied to a liquid ejecting head and a liquid ejecting apparatus that eject liquid other than ink. Other liquid ejecting heads include, for example, various recording heads used in image recording apparatuses such as printers, color material ejecting heads used in the manufacture of color filters such as liquid crystal displays, organic EL displays, and FEDs (field emission displays). Examples thereof include an electrode material ejection head used for electrode formation, a bio-organic matter ejection head used for biochip production, and the like, and can also be applied to a liquid ejection apparatus provided with such a liquid ejection head.

  I Inkjet recording device (recording device), 1 Inkjet recording head (recording head), 11, 31, 51, 71 Backwash switching valve unit, 12, 32, 52, 72 Main body, 13, 33, 53, 73 Ink supply port, 14, 34, 54, 74 Backwash port, 15, 35, 55, 75 Connection port, 16, 36, 56, 76 Switching chamber, 17, 28, 29, 37, 38, 45, 57, 68, 69, 77, 88, 89 flow path, 20, 21, 40, 41, 60, 80, 81 valve body, 100 pump

Claims (8)

A first flow path for allowing the liquid ejected from the liquid ejecting head to flow toward the switching chamber; a second flow path for discharging the cleaning liquid during backwashing from the switching chamber; and the liquid ejecting head from the switching chamber. A third flow path for flowing the liquid toward the flow path and flowing the cleaning liquid introduced from the flow path of the liquid jet head toward the switching chamber;
Open and close between the first flow path and the switching chamber and between the second flow path and the switching chamber, and operate so that when one is opened, the other is closed A switching valve unit for backwashing comprising a valve body. In the switching valve unit for backwashing according to claim 1,
The valve body is integrally connected via a rod, and the first flow path and the switching chamber are normally communicated with each other by a spring force acting via one valve body, and at the same time, the first While the valve body is opened and closed so as to block between the flow path of 2 and the switching chamber,
At the time of backwashing, the valve body is integrally moved by pushing the rod against the spring force so that the second flow path and the switching chamber communicate with each other, and the first The switching valve unit for backwashing characterized in that the valve element is opened and closed so that the space between the flow path and the switching chamber is closed. In the switching valve unit for backwashing according to claim 1,
The valve body is integrally connected via a rod, and the first flow path and the switching chamber are normally communicated with each other by a spring force acting via one valve body, and at the same time, the first While the valve body is opened and closed so as to block between the flow path of 2 and the switching chamber,
At the time of backwashing, the valve body is moved integrally by pushing the rod against the spring force with an external force based on the difference between the negative pressure of the pump acting on the second flow path and the atmospheric pressure. The valve body is opened and closed so that the second channel and the switching chamber communicate with each other, and the first channel and the switching chamber are closed. Switching valve unit for backwashing. In the switching valve unit for backwashing according to claim 1,
Two valve bodies are disposed in the switching chamber so as to be movable between the first flow path side and the second flow path side, and the distance between the two is connected by a spring so as to expand and contract,
In a state where the switching chamber is filled with liquid, each of the valve bodies moves to the first flow path side and the second flow path side by the spring force of the spring, and the first flow path and Blocking between the switching chamber and between the second flow path and the switching chamber,
The switching chamber has a negative pressure when the liquid is discharged from the switching chamber to the outside through the third channel in a state where the communication state between the second channel and the switching chamber is blocked. As a result, the valve body on the first flow path side is moved to the second flow path side, so that the liquid can be supplied to the switching chamber by communicating between the first flow path and the switching chamber. While
At the time of backwashing, the rod on the second flow path side based on the difference between the negative pressure of the pump acting on the second flow path and the atmospheric pressure is in the direction from the first flow path to the second flow path. The tip end of the rod is made to be larger than the displacement amount in the direction of the other rod on the first flow path side based on the difference between the negative pressure and the atmospheric pressure in the switching chamber. The flow path between the first flow path and the switching chamber is closed by bringing the valve body into contact with the flow path side valve body and moving the valve body toward the first flow path side. A switching valve unit for backwashing characterized in that a flow path between a path and the switching chamber is opened.   A liquid jet head comprising the backwash switching valve unit according to any one of claims 1 to 4.   A liquid ejecting apparatus comprising the liquid ejecting head according to claim 5. In a liquid jet recording apparatus equipped with a liquid jet recording head having the backwashing switching valve unit according to claim 2,
When the liquid ejecting head is moved in a non-printing area during backwashing, the rod tip is brought into contact with a fixing portion on the apparatus main body side, thereby obtaining a force for pushing the rod against the spring force. A liquid ejecting apparatus configured as described above. In a liquid jet recording apparatus equipped with a liquid jet recording head having the backwashing switching valve unit according to claim 2,
When the liquid ejecting head is moved to a non-printing area during backwashing processing, a convex portion on the apparatus main body side is utilized by using a reduction amount in which the nozzle surface is relatively lowered when the liquid ejecting head is attached to the flushing cap. A liquid ejecting apparatus configured to obtain a force to push the rod against the spring force by pushing the rod having a tip abutted on the top upward.

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