Liquid discharge head and liquid discharge device

Abstract

To provide a liquid discharge head and a liquid discharge device which can suppress variation in an amount and speed of droplets to be discharged from a nozzle.SOLUTION: A liquid discharge head includes a nozzle plate 15 where a nozzle 14 is formed, and a needle valve 31 as a valve member for opening / closing the nozzle. The liquid discharge head includes a sealing member 34 which is brought into contact with a housing as a housing and the needle valve 31, and seals between a liquid chamber 17 and a piezoelectric element storage part 3330 as a moving means storage part. The sealing member 34 is held on a holding groove 44 provided on the housing so as to be immovable in the moving direction of the needle valve.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head and a device for ejecting liquid. [Background technology]

[0002] Conventionally, a liquid ejection head is known that includes a nozzle plate having nozzles formed therein, a valve member that opens and closes the nozzles, a moving means that moves the valve member between an open position that opens the nozzles and a closed position that closes the nozzles, a housing that has a liquid chamber that contains liquid to be ejected from the nozzles and a moving means housing portion that houses the moving means, and a sealing member that abuts against the housing and the valve member and seals between the liquid chamber and the moving means housing portion.

[0003] Patent Document 1 describes a liquid ejection head in which a valve member has an annular holding groove for holding an O-ring serving as a sealing member. Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is a risk that the amount and speed of droplets ejected from the nozzles may vary. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, the present invention provides a liquid ejection head comprising a nozzle plate having nozzles formed therein, a valve member for opening and closing the nozzles, a moving means for moving the valve member between an open position for opening the nozzles and a closed position for blocking the nozzles, a housing having a liquid chamber for containing liquid to be ejected from the nozzles and a moving means accommodating section for accommodating the moving means, and a sealing member that abuts the housing and the valve member and seals the space between the liquid chamber and the moving means accommodating section, wherein the sealing member is held immovable in the housing in the direction of movement of the valve member. [Effects of the Invention]

[0006] According to the present invention, it is possible to suppress variations in the amount and speed of droplets ejected from the nozzles. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is an explanatory diagram illustrating the appearance of a liquid ejection head according to an embodiment of the present invention. [Figure 2] FIG. 2 is an overall cross-sectional view of the liquid ejection head. [Figure 3] 5A and 5B are diagrams illustrating the arrangement of a heater provided in the first housing. [Figure 4] FIG. 2 is a schematic diagram showing the basic configuration of a liquid ejection module. [Figure 5] FIG. 10 is an enlarged view of the periphery of a valve through-hole of a liquid ejection head according to a comparative example. [Figure 6] FIG. 4 is an enlarged view of the periphery of a valve through-hole of the liquid ejection head of the present embodiment. [Figure 7] 10A and 10B are diagrams illustrating the movement of the needle valve from a nozzle-closing position to a nozzle-opening position. [Figure 8] 5A and 5B are diagrams illustrating a parting line of a sealing member. [Figure 9] FIG. 10 is a schematic diagram showing an embodiment in which the holding groove is a triangular groove. [Figure 10] FIG. 10 is a schematic diagram illustrating the configuration of a liquid ejection head including a liquid ejection module according to a modified example. [Figure 11] FIG. 10 is a schematic diagram showing another modified example of the liquid ejection module. [Figure 12] FIG. 1 is a schematic perspective view of a device for discharging liquid. [Figure 13] FIG. 1 is a diagram showing an example of a supply device that supplies paint to a plurality of liquid ejection heads included in a device that ejects liquid. [Figure 14] FIG. 1 is a diagram showing an example of an electrode manufacturing apparatus. DETAILED DESCRIPTION OF THE INVENTION

[0008] The best mode for carrying out the present invention will be described below with reference to the drawings. Note that a person skilled in the art can easily modify or alter the present invention within the scope of the claims to create other embodiments, and these modifications and alterations are included within the scope of the claims. The following description is an example of the best mode for carrying out the present invention and does not limit the scope of the claims.

[0009] 1A and 1B are explanatory diagrams showing the appearance of a liquid ejection head 10 according to an embodiment of the present invention, in which Fig. 1A is an overall perspective view of the liquid ejection head 10, and Fig. 1B is an overall side view of the same head. 1, the longitudinal direction of the liquid ejection head 10 (the direction in which the nozzles 14 are arranged) is the X direction, and the lateral direction of the liquid ejection head 10 is the Y direction. The height direction of the liquid ejection head 10 (the opening and closing direction of the needle valve 31, the movement direction of the needle valve 31, and the direction in which liquid is ejected from the nozzles 14) is the Z direction. The definitions of these coordinates will be the same in the subsequent figures unless otherwise specified.

[0010] The liquid ejection head 10 includes a housing 11 serving as a case. The housing 11 is composed of a first housing 11a and a second housing 11b. The second housing 11b is laminated and joined to the first housing 11a. The first housing 11a is made of a material such as metal that has high thermal conductivity and high resistance to liquids such as ink, and the second housing 11b is made of the same material as the first housing 11a. In this embodiment, the first housing 11a and the second housing 11b are made of stainless steel (SUS). However, if the device does not use a heater to heat the liquid, a material with low thermal conductivity such as resin may be used.

[0011] The first housing 11a is provided with heaters 12 as heating means on its front and back surfaces. The heaters 12 are temperature-controllable and heat the first housing 11a. The second housing 11b is provided with a connector 13 on its top for communicating electrical signals.

[0012] FIG. 2 is an overall cross-sectional view of the liquid ejection head 10, taken along the line AA in FIG. 1(a). The first housing 11a holds a nozzle plate 15. The nozzle plate 15 is provided with a plurality of nozzles 14 that eject liquid. The plurality of nozzles 14 are arranged in the longitudinal direction (X direction) of the liquid ejection head 10.

[0013] A supply port 16 for supplying liquid such as ink into the head is provided at one end in the X direction of the second housing 11b, and a recovery port 18 for discharging the liquid from the head is provided at the other end in the X direction.

[0014] The first housing 11a includes a liquid chamber 17 that contains liquid. The supply port 16 is connected to one end of the liquid chamber in the X direction, and the recovery port 18 is connected to the other end of the liquid chamber 17 in the X direction. As indicated by arrow a1 in the figure, liquid supplied from the supply port 16 to one end of the liquid chamber in the X direction moves within the liquid chamber 17 toward the other end in the X direction, as indicated by arrow a2 in the figure. Then, as shown by the arrow a3 in the figure, it moves inside the recovery port 18 and is discharged from the head.

[0015] A plurality of liquid ejection modules 30 are arranged between the supply port 16 and the recovery port 18. The number of liquid ejection modules 30 corresponds to the number of nozzles 14, and in this example, a configuration is shown in which eight liquid ejection modules 30 corresponding to the eight nozzles 14 arranged in a row are provided. Note that the number and arrangement of the nozzles 14 and liquid ejection modules 30 are not limited to those described above. For example, the number of nozzles 14 and liquid ejection modules 30 may be one instead of multiple. Also, the number may be eight or more or less. The nozzles 14 and liquid ejection modules 30 may be arranged in multiple rows instead of a single row.

[0016] Each liquid ejection module 30 includes a needle valve 31, which is a valve member that opens and closes the nozzle 14, and a piezoelectric element 32, which is a moving means for moving the needle valve 31. The piezoelectric element 32 is connected to a drive control device via a connector 13. When a voltage is applied to the piezoelectric element 32 by the drive control device, the piezoelectric element 32 contracts in the Z direction, causing the needle valve 31 to rise and open the nozzle 14, thereby ejecting liquid from the nozzle 14. When no voltage is applied to the piezoelectric element 32, the needle valve 31 closes the nozzle 14. In this state, liquid is not ejected from the nozzle 14. A solenoid may be used as a moving means for moving the needle valve 31.

[0017] A restricting member 20 is provided on the top of the liquid discharging module 30 to restrict upward movement of the liquid discharging module 30. Housing seal members 19 are provided at the joint between the first housing 11a and the second housing 11b at the supply port 16 and at the joint between the first housing 11a and the second housing 11b at the recovery port 18. In this example, O-rings are used as the housing seal members, and the O-rings prevent liquid from leaking from the joint between the first housing 11a and the second housing 11b.

[0018] 3 is a diagram illustrating the arrangement of the heaters 12 provided in the first housing 11a. As indicated by the dashed lines in FIG. 3, the heaters 12 provided on the front and back surfaces of the first housing 11a are provided near the nozzles 14 so as to cross the nozzles 14.

[0019] FIG. 4 is a schematic diagram showing the basic configuration of the liquid ejection module 30. As shown in FIG. In addition to the needle valve 31 and piezoelectric element 32 described above, the liquid discharging module 30 mainly includes a fixing member 33, a holder 35, and a plug 36. The holder 35 has a driver housing portion 35a therein, and the driver housing portion 35a houses and holds the piezoelectric element 32. The holder 35 is made of a metal such as stainless steel, for example, SUS304 or SUS316L. The holder 35 is a frame in which a plurality of elongated members extending in the longitudinal direction are arranged around the piezoelectric element 32 (for example, four members arranged at 90° intervals), and the piezoelectric element 32 is inserted into the holder 35 through the spaces between the elongated members that make up the holder 35.

[0020] A needle valve 31 is connected to the tip of the holder 35 on the nozzle 14 side. In addition, a bellows portion 35b is formed on the nozzle 14 side of the holder 35, and is elastically expandable and contractible in the longitudinal direction of the piezoelectric element 32. The bellows portion 35b is used to cause the nozzle-side tip of the holder 35 to expand and contract in the Z direction in the same way as the piezoelectric element 32 when the piezoelectric element 32 expands and contracts.

[0021] A fixing member 33 is connected to the base end of the holder 35, which is opposite to the nozzle 14 side. In other words, the fixing member 33 is housed in the upper end of the second housing 11b. The fixing member 33 has a through-hole 33a extending in the radial direction. A positioning screw 60 is screwed into the through-hole 33a from outside the second housing 11b. The positioning screw 60 is inserted into a longitudinally elongated hole 11b1 formed in the upper end of the second housing 11b. Therefore, the positioning screw 60 can move a predetermined distance in the Z direction. The positioning screw 60 is tightened while positioning the fixing member 33 in the Z direction.

[0022] A female screw hole 11b2 is formed in the upper end opening of the second housing 11b. A plug 36 that abuts against the restricting member 20 of Fig. 2 is screwed into this female screw hole 11b2. The plug 36 abuts against the upper end of the fixing member 33 that has been positioned in the longitudinal direction by the positioning screw 60, thereby finally fixing the fixing member 33 in place.

[0023] A compression spring 37 is disposed at the bottom end of the second housing 11b. The compression spring 37 biases the piezoelectric element 32, the holder 35 that holds the piezoelectric element 32, and the like upward.

[0024] The needle valve 31 is made of a metal material such as stainless steel (SUS), and an elastic member 40 made of rubber or the like is provided at the tip of the needle valve 31 on the nozzle 14 side. When the elastic member 40 of the needle valve 31 is pressed against the nozzle plate 15, the elastic member 40 is compressed, thereby reliably closing the nozzle 14 with the needle valve 31.

[0025] The first housing 11a is provided with a valve through-hole 41 through which the needle valve 31 passes. An annular sealing member 34 such as an O-ring is provided inside the valve through-hole 41 to seal the liquid in the liquid chamber 17 so as not to leak and to prevent the liquid from entering the piezoelectric element accommodating portion 330.

[0026] FIG. 5 is an enlarged view of the periphery of a valve through-hole 41 of a liquid ejection head of a comparative example. 5, in the liquid ejection head of the comparative example, an annular holding groove 31a that holds an annular sealing member 34 is provided in the needle valve 31. The groove width (length in the Z direction) of this holding groove 31a is wider than the wire diameter (thickness) of the sealing member 34, and the sealing member 34 is held within the holding groove 31a so as to be movable within a predetermined range in the Z direction.

[0027] Therefore, depending on the difference between the sliding resistance between the sealing member 34 and the inner circumferential surface of the valve through-hole 41 and the sliding resistance between the sealing member 34 and the bottom surface of the retaining groove 31a, when the needle valve 31 opens or closes, the sealing member 34 moves in the Z direction along with the needle valve 31 and slides against the inner circumferential surface of the valve through-hole 41, or stays in place and slides against the bottom surface of the groove. Furthermore, if the sliding resistance in the circumferential direction is not constant, the sealing member 34 may tilt or twist in the Y direction in the figure. As a result, the movement resistance during the opening and closing of the needle valve 31 varies between liquid ejection modules 30, resulting in variations in the movement amount and movement speed of the needle valve 31. The variation in the movement amount of the needle valve 31 affects the variation in the distance between the nozzle 14 and the needle valve 31 when the nozzle 14 is opened, and this variation results in variations in the fluid resistance when the liquid in the liquid chamber 17 flows into the nozzle 14. Such variations result in variations in the ejection speed of the liquid ejected from the nozzle 14 and the amount of liquid ejected per unit time. Furthermore, variations in the movement speed of the needle valve 31 affect the variations in the time the needle valve 31 is open, which in turn affects the size of the ejected droplets when the needle valve 31 is opened and closed at a high frequency. As a result, there is a risk that variations in the ejection performance will occur between the nozzles.

[0028] Therefore, in this embodiment, the sealing member 34 is held immovable in the moving direction (Z direction) of the needle valve 31. The characteristic features of this embodiment will be described below with reference to the drawings.

[0029] FIG. 6 is an enlarged view of the periphery of the valve through-hole 41 of the liquid ejection head 10 of this embodiment. 6, in this embodiment, the upper end of the valve through-hole 41 in the first housing 11a is cut away to form an annular retaining groove 44 that holds the annular sealing member 34 between the second housing 11b and the first housing 11a. The groove width W (length in the Z direction) of the retaining groove 44 is narrower than the length of the sealing member 34 in the Z direction in an uncompressed state. Therefore, the sealing member 34 in the retaining groove 44 is sandwiched and held between the first housing 11a and the second housing 11b in the Z direction, which is the movement direction of the needle valve 31. As a result, the sealing member 34 is held in the retaining groove 44 so as to be unable to move in the Z direction.

[0030] In this embodiment, the sealing member 34 may be an O-ring, D-ring, X-ring, T-ring, or the like, as long as it abuts against the outer circumferential surface of the needle valve 31 and the retaining groove 44 with a predetermined abutment pressure to seal the liquid in the liquid chamber 17 so as to prevent leakage. The O-ring has a circular or elliptical cross-sectional shape in the cross section of FIG. 6, the D-ring has a cross-sectional shape resembling the letter "D" with a portion of a circle cut away by a straight line, and the X-ring and T-ring have grooves or ribs so that the cross-sectional shape resembles the letter "X" or "T." In this embodiment, the sealing member 34 is shaped intermediate between an O-ring and a D-ring.

[0031] Furthermore, elastic materials such as rubber, resin, and elastomer are preferred as the material for the sealing member 34, but other materials may also be used as long as they are capable of sealing in the ink. Furthermore, the material for the sealing member 34 must have properties such as chemical resistance and solvent resistance, and examples of materials for the sealing member include perfluoroelastomer (4275B, manufactured by Morisei Chemical Industry Co., Ltd.). The length (thickness in the Z direction) of the sealing member 34 in the Z direction (needle valve movement direction) is preferably 1 mm or more. The inner diameter of the sealing member 34 is at least 1 mm, and the outer diameter is about 3 mm.

[0032] The sealing between the sealing member 34 and the housing 11 is achieved by sandwiching it between the first housing 11a and the second housing 11b. Specifically, the groove width W of the retaining groove 44 is set shorter than the thickness of the sealing member 34 (in an uncompressed state) in the Z direction so that the crushing ratio of the sealing member 34 in the Z direction is 15±10%. If the crushing ratio is less than 5%, the seal with the housing is insufficient, and leakage may occur due to the liquid pressure in the liquid chamber. On the other hand, if the crushing ratio exceeds 25%, permanent deformation of the sealing member may occur.

[0033] The crushing ratio can be calculated by (W0-W) / W0×100(%), where W0 is the thickness in the Z direction of the sealing member 34 in an uncompressed state and W is the thickness in the Z direction in a compressed, i.e., crushed, state.

[0034] In addition, in this configuration, it is preferable that the inner diameter d of the bottom surface of the annular retaining groove 44 is equal to or greater than the outer diameter of the uncompressed sealing member 34. This eliminates the need to reduce the diameter of the sealing member 34 before assembling it into the retaining groove 44, making it easier to assemble the sealing member 34 into the retaining groove 44.

[0035] The sealing member 34 seals the needle valve 31 by expanding the outer diameter D of the sliding portion of the needle valve 31 with the sealing member 34, making it larger than the inner diameter of the sealing member 34 in an uncompressed state (the inner diameter of the sealing member in an unexpanded state < the outer diameter D of the sliding portion of the needle valve 31). The elongation rate of the sealing member 34 can be set to an optimal range depending on the material and shape of the sealing member 34. For example, by setting the elongation rate of the sealing member to half or less of the elongation rate at break, the sliding portion of the sealing member 34 with the needle valve 31 can be effectively sealed. Furthermore, the elongation rate of the sealing member 34 is preferably set to 5% or more and 25% or less. Setting the elongation rate of the sealing member 34 to 5% or more and 25% or less reduces the sliding resistance between the sealing member 34 and the needle valve 31, while preventing the liquid in the liquid chamber 17 from leaking into the driver housing portion 35a due to the pressure applied to the liquid.

[0036] The elongation rate can be calculated by (D1-D0) / D0 x 100(%), where D0 is the inner diameter of the sealing member 34 in its non-expanded state and D1 is the inner diameter of the sealing member 34 in its expanded state. The inner diameter D1 of the sealing member 34 in its expanded state is equal to the outer diameter D of the sliding portion of the needle valve 31. Therefore, the elongation rate can also be calculated by (D-D0) / D1 x 100(%).

[0037] The sealing member 34 may be compressed in the Z direction by the first housing 11a and the second housing 11b, causing the sealing member 34 to collapse and reduce its inner diameter, thereby coming into contact with the needle valve 31 and sealing the needle valve 31. In this configuration, the inner diameter of the sealing member in an uncompressed state can be made greater than the outer diameter D of the needle valve, making it easier to assemble the sealing member 34 and the needle valve 31.

[0038] Furthermore, it is preferable to use the sealing member 34 whose surface has been coated with a low-friction material such as fluorine or silicone and whose surface has been subjected to a low-friction treatment. Here, the low-friction material is a material that reduces the frictional resistance of the member before coating. An example of a sealing member whose surface is coated with a low-friction material is an SP-treated O-ring (NOK Corporation). By using the sealing member 34 whose surface has been coated with a low-friction material and subjected to a surface low-friction treatment, it is possible to reduce the sliding resistance with the needle valve 31. Furthermore, it becomes easier to insert the needle valve 31 into the sealing member 34, and the assembly work of the sealing member 34 and the needle valve 31 can be simplified.

[0039] Furthermore, the contact points of the needle valve 31 with the sealing member 34 may be coated with a low-friction material such as fluorine or silicone to reduce friction. Examples of the coating material that may be used to coat the contact points of the needle valve with the sealing member 34 include Baycoat (Yoshida SKT Co., Ltd.). By performing this low-friction treatment on the contact points of the needle valve 31 with the sealing member 34, it is possible to reduce the sliding resistance with the sealing member 34. This also makes it easier to insert the needle valve 31 into the sealing member 34, which in turn facilitates the assembly of the sealing member 34 and the needle valve 31.

[0040] Furthermore, the contact point of the needle valve 31 with the sealing member 34 may be mirror-polished to an arithmetic mean roughness Ra of 0.1 μm or less to reduce friction. Furthermore, after mirror-polishing to an arithmetic mean roughness Ra of 0.1 μm or less, further low-friction surface treatment such as DLC (Diamond-Like Carbon) coating can be preferably performed to reduce the sliding resistance with the sealing member. Furthermore, the contact point of the needle valve 31 with the sealing member 34 may be surface-coated to an arithmetic mean roughness Ra of 0.1 μm or less.

[0041] The above-described low-friction treatment may be performed on the surface of either the sealing member 34 or the needle valve 31, or on both the sealing member 34 and the needle valve 31. Such low-friction treatment can reduce the sliding resistance that occurs between the needle valve 31 and the sealing member 34 when the needle valve 31 moves. By reducing the absolute value of the sliding resistance, the variation in sliding resistance itself can be reduced. This can reduce the variation in liquid ejection performance.

[0042] Figure 7 shows the state in which the needle valve 31 is moved from the nozzle closing position to the nozzle opening position, where Figure 7(a) shows the state in which the needle valve 31 is positioned at the nozzle closing position, and Figure 7(b) shows the state in which the needle valve 31 is positioned at the nozzle opening position. In this embodiment, the sealing member 34 is clamped by the side surfaces of the holding groove 44, and is held in the holding groove 44 so as to be unable to move in the Z direction, which is the movement direction of the needle valve 31. As a result, the sealing member 34 slides only on the outer peripheral surface of the needle valve 31 when the needle valve 31 moves. Therefore, the sealing member 34 does not slide in the Z direction against the inner wall of the valve through-hole 41. Therefore, in all liquid ejection modules 30, the sealing member 34 slides only on the needle valve 31, and variation in movement resistance during the opening and closing operation of the needle valve 31 between the liquid ejection modules 30 is suppressed. As a result, variation in the movement amount and movement speed of the needle valve 31 is suppressed, and variation in ejection performance between the nozzles can also be suppressed.

[0043] Figure 8 is a diagram illustrating the parting line 34a of the sealing member 34, where Figure 8(a) shows the parting line 34a of the sealing member 34 of this embodiment, and Figure 8(b) shows the parting line 34a of the sealing member 34 of a comparative example. The parting line 34a of the sealing member 34 is a protruding portion (also called a burr line) that is formed when burrs are removed after molding with a metal mold. 8(b), the parting line 34a of the sealing member 34 is generally formed in the center in the central axis direction (Z direction in the figure) of the annular sealing member 34. However, in such a configuration, the parting line 34a of the sealing member 34 abuts against the outer peripheral surface of the needle valve 31. Because the height of the parting line 34a is non-uniform, when the parting line 34a abuts against the needle valve 31, the contact pressure between the needle valve 31 and the sealing member 34 becomes non-uniform in the circumferential direction, which may result in localized leakage.

[0044] 8(a), the mold structure is devised so that the parting line 34a is formed at a position that does not contact the side surface (surface perpendicular to the Z direction) of the retaining groove 44 that seals the housing and the needle valve 31. This makes it possible to prevent the contact pressure between the needle valve 31 and the sealing member 34 from becoming uneven in the circumferential direction, and the contact pressure with the side surface of the retaining groove 44 from becoming uneven in the circumferential direction, thereby preventing localized leakage.

[0045] In this embodiment, the parting line 34a of the sealing member 34 is not in contact with the housing 11 and the needle valve 31, but the parting line 34a may be in light contact with them as long as the contact pressure at the sealed portion is not affected. In other words, the parting line 34a may be in contact with the needle valve 31 or the housing 11 at a contact pressure that is sufficiently lower than the contact pressure at the sealed portion.

[0046] FIG. 9 is a schematic diagram showing an embodiment in which the holding groove 44 is a triangular groove. As shown in FIG. 9 , by forming the retaining groove 44 as a triangular groove, outward collapse of the sealing member 34 (collapse away from the needle valve 31) due to compression in the Z direction by the first housing 11a and the second housing 11b is suppressed. As a result, the sealing member 34 collapses in a direction that further reduces the inner diameter, increasing the contact pressure of the sealing member 34 with the needle valve 31 and more reliably sealing between the sealing member 34 and the needle valve 31. Note that the triangular groove here refers to a groove having no bottom, and at least one of the two side surfaces (wall surfaces perpendicular to the Z direction) of the retaining groove 44 that come into contact with the sealing member 34 is inclined in the movement direction (Z direction) of the needle valve 31 (the Z direction position of one end of the side surface is inclined so that the Z direction position of the other end is different from each other). Both side surfaces of the retaining groove 44 may be inclined, or either one of them may be inclined. Furthermore, the groove is not limited to a triangular groove, and any shape may be used as long as at least one of the two side surfaces is inclined in the Z direction so that the groove width W (distance between the side surfaces) of the retaining groove 44 gradually narrows as it moves away from the needle valve 31.For example, the groove may have a trapezoidal cross-sectional shape parallel to the Z direction.

[0047] Although the retaining groove 44 may be provided in either the first housing 11a or the second housing 11b, it is preferable that the retaining groove 44 be formed in both the first housing 11a and the second housing 11b. By forming the retaining groove 44 in both the first housing 11a and the second housing 11b, the sealing member 34 can also seal between the first housing 11a and the second housing 11b. Furthermore, after the sealing member 34 is assembled into a notch formed in either the first housing 11a or the second housing 11b, the second housing 11b can be assembled to the first housing 11a, compressing the sealing member 34 in the Z direction. This eliminates the need to press the sealing member 34 into the retaining groove 44 to assemble it, making it easier to assemble the sealing member 34.

[0048] FIG. 10 is a schematic diagram of a liquid ejection head including a liquid ejection module 30A according to a modified example. As shown in FIG. 10, a liquid ejection module 30A of this modified example has an arm member 55, and the arm member 55 amplifies the displacement of the piezoelectric element 32, thereby increasing the movement amount of the needle valve 31.

[0049] The liquid discharge modules 30A are arranged alternately in the X direction in two rows in the piezoelectric element accommodating portion 330 of the second housing 11b with the needle valves 31 facing each other. The liquid discharge modules 30A are also arranged so that the arm members 55 partially overlap when viewed from the X direction.

[0050] Here, staggered arrangement of the liquid ejection modules 30 can also be said to mean that a liquid ejection module in which the actuator 2 is located on one side of the nozzle array and a liquid ejection module in which the actuator 2 is located on the other side of the nozzle array are arranged facing each other, and are arranged along the nozzle array direction (X direction) so that portions of the arm members 3 overlap each other when viewed from the nozzle array direction (X direction).

[0051] The arm member 55 is rotatably supported by a support shaft 55a, one end of which is adhesively fixed to the holder 35 that holds the piezoelectric element 32, and the other end of which is in contact with an arm receiving portion 54 that is fixed to the needle valve 31. A contact portion 55d at the other end of the arm member 55 that comes into contact with the arm receiving portion 54 is hemispherical and protrudes toward the arm receiving portion 54, or is crescent-shaped when viewed from the X direction, so that the arm member 55 smoothly contacts the arm receiving portion 54 when it rotates.

[0052] Furthermore, an escape hole 55b through which the needle valve 31 passes is formed at the other end of the arm member 55. The inner diameter of the escape hole 55b is larger than the outer diameter of the needle valve 31, so that the needle valve 31 does not come into contact with the arm member 55 when the arm member 55 rotates.

[0053] The end of the needle valve 31 opposite to the nozzle plate side passes through a spring receiving plate 52. A compression spring 53 serving as a biasing means is provided between an arm receiving portion 54 fixed to the needle valve 31 and the spring receiving plate 52, and biases the needle valve 31 toward the nozzle plate 15 via the arm receiving portion 54.

[0054] The compression spring 53 biases the needle valve 31 toward the nozzle plate 15, thereby stabilizing the movement of the needle valve 31 between an open position where it opens the nozzle 14 and a closed position where it closes the nozzle 14. The spring support plate 52 is attached to a fixed member 51 fixed to the second housing 11b.

[0055] By providing the arm member 55, the piezoelectric element 32, which is the largest component of the liquid ejection module 30A, can be disposed at the Y-direction end of the piezoelectric element accommodating section 330. This allows the fixing member 51 to be disposed in the center of the Y-direction of the piezoelectric element accommodating section 330, and the spring receiving plate 52 can be fixed with one fixing member 51. This allows the liquid ejection head 10 to be made smaller.

[0056] Furthermore, in this modified example, the liquid ejection modules 30A are arranged alternately in the X direction so that the arm members 55 partially overlap when viewed from the X direction. This allows the liquid ejection head to be made smaller in the Y direction compared to a configuration in which the arm members do not overlap.

[0057] When the fixed portion 55c is displaced in the Z direction together with the piezoelectric element 32 due to the displacement of the piezoelectric element 32, the arm member 55 rotates around the support shaft 55a as a fulcrum. When the arm member 55 rotates due to the displacement of the piezoelectric element 32, the contact portion 55d of the arm member 55 lifts the arm receiving portion 54 against the biasing force of the compression spring 53. As a result, the needle valve 31 lifts together with the arm receiving portion 54, opening the nozzle 14, and droplets are ejected from the nozzle 14 due to the pressure applied to the liquid in the liquid chamber 17.

[0058] Before the arm member 55 rotates, the top of the contact portion 55d is in contact with the arm receiving portion 54. However, as the arm member 55 rotates due to the displacement of the piezoelectric element 32, the contact position of the contact portion 55d with the arm receiving portion 54 shifts to the left side in FIG. 10 (toward the other end of the arm member). As described above, the contact surface of the contact portion 55d with the arm receiving portion 54 has an arc shape when viewed from the X direction, so the contact position of the contact portion 55d with the arm receiving portion 54 can be smoothly shifted. This allows the arm member 55 to rotate smoothly, and the needle valve 31 to be displaced stably. This makes it possible to suppress variations in droplets.

[0059] Furthermore, the support shaft 55a supporting the arm member 55 is located closer to the fixed portion 55c than the center of the arm member 55 in the longitudinal direction (Y direction). This makes the rotation radius of the contact portion 55d longer than the rotation radius of the fixed portion 55c, and the Z-direction displacement of the contact portion 55d is greater than the Z-direction displacement of the fixed portion 55c. This causes the displacement of the contact portion 55d lifting the arm support portion 54 to be greater than the Z-direction displacement of the piezoelectric element 32. As a result, the displacement of the piezoelectric element 32 is amplified by the arm member 55, increasing the movement of the needle valve 31. This increases the gap between the nozzle 14 and the tip of the needle valve 31 when the needle valve 31 is in the open position, making it easier for liquid to flow into the nozzle 14 and increasing the size of droplets ejected from the nozzle 14. This improves printing efficiency and shortens printing time. Furthermore, it is possible to use a piezoelectric element 32 with a small amount of displacement, which allows the piezoelectric element 32 to be made smaller, and the liquid ejection head 10 to be made smaller effectively.

[0060] Figure 11 is a schematic diagram showing another modified example of the liquid ejection module, in which Figure 11(a) is a schematic diagram showing a state in which the needle valve 31 closes the nozzle 14, and Figure 11(b) is a schematic diagram showing a state in which the needle valve 31 opens the nozzle 14. 11 includes a needle valve 31, a piezoelectric element 32, a moving member 61, a pair of arm members 62, and a leaf spring member 63. One end of the moving member 61 is fixed to the piezoelectric element 32, and the pair of arm members 62 are rotatably attached to the other end, and the moving member 61 is attached to a holder 35 that holds the piezoelectric element 32 so as to be movable in the Z direction. The pair of arm members 62 are rotatably supported by a support shaft 62a attached to the holder 35.

[0061] The leaf spring member 63 is formed by bending a stainless steel (SUS) sheet metal, and includes a valve connection portion 63a connected to the needle valve, a pair of inclined portions 63b as elastic deformation portions, and a pair of arm connection portions 63c. The needle valve 31 is bonded to the valve connection portion 63a with an adhesive, and the inclined portions 63b extend diagonally upward in the figure from both ends of the valve connection portion 63a. The arm connection portions 63c are fitted into slits provided in the arm member 62 and attached to the arm member 62.

[0062] 11(a), when the needle valve 31 closes the nozzle 14 (when the needle valve 31 is in the closed position), the pair of inclined portions 63b of the leaf spring member 63 elastically deform as shown by the dashed lines in the figure, thereby generating an urging force that presses the needle valve 31 against the nozzle plate 15.

[0063] As shown by the black arrow in FIG. 11(b), the piezoelectric element 32 is displaced toward the nozzle 14, causing the moving member 61 to move toward the nozzle and push the pair of arm members 62 toward the nozzle. This causes the pair of arm members 62 to rotate around the support shaft 62a as a fulcrum. As the pair of arm members 62 rotate, both ends of the leaf spring member 63 move in directions away from each other. This lifts the needle valve 31, opening the nozzle 14 and causing liquid to be ejected from the nozzle 14 (this corresponds to a state in which the needle valve 31 is in the open position that opens the nozzle 14).

[0064] The liquid ejection head 10 described above is a valve jet type, and can eject highly viscous liquids and large droplets (diameters of tens to hundreds of μm) toward a target object located at a distance (tens of mm away). Furthermore, the nozzle diameter can be increased, and liquids containing large particle diameter materials can also be ejected effectively. Because the liquid ejection head 10 can eject highly viscous liquids, it is suitable for painting car and truck bodies, aircraft fuselages, building walls, road surfaces, and the like, as well as for printing images. It can also be used favorably for forming electrodes for lithium-ion batteries and the like installed in vehicle bodies.

[0065] Next, an example of a liquid ejection device having the above-described liquid ejection head 10 will be described.

[0066] FIG. 12 is a schematic perspective view of a device 100 for discharging liquid. The liquid discharging device 100 includes a movable frame unit 120 that is installed facing an object 200 to be discharged. The frame unit 120 includes a Y-axis rail 101 extending horizontally, a plurality of X-axis rails 102 extending vertically and provided at predetermined intervals, and a Z-axis rail 103 intersecting the X-axis rail 102 and the Y-axis rail 101.

[0067] Each X-axis rail 102 holds a Y-axis rail 101 extending horizontally so that the Y-axis rail 101 can move in the X direction (the direction in which the nozzles of the liquid ejection head are arranged, which is the vertical direction). Furthermore, the Y-axis rail 101 holds a Z-axis rail 103 so that the Z-axis rail 103 can move in the Y direction. The Z-axis rail 103 holds the carriage 110 so that the carriage 110 can move in the Z direction.

[0068] The carriage 110 is equipped with a head holder 130. The head holder 130 holds, for example, liquid ejection heads of different colors. For example, it holds a C-color liquid ejection head that ejects cyan paint, an M-color liquid ejection head that ejects magenta paint, a Y-color liquid ejection head that ejects yellow paint, and a K-color liquid ejection head that ejects black paint. It may also hold a W-color liquid ejection head that ejects white paint. It may also hold a liquid ejection head that ejects clear (transparent) coating paint, so that coating can be applied simultaneously with printing.

[0069] The carriage 110 also includes a first Z-direction driver 140a that moves the carriage 110 in the Z direction (the liquid ejection direction, which is the direction toward and away from the ejection target 200) along the Z-rail 103. The carriage 110 also includes a Y-direction driver 150 that moves the Z-rail 103 in the Y direction (the horizontal direction, which is perpendicular to both the liquid ejection direction and the nozzle arrangement direction of the liquid ejection head) along the Y-rail 101. The carriage 110 also includes an X-direction driver 160 that moves the Y-rail 101 in the X direction (the nozzle arrangement direction of the liquid ejection head, which is the vertical direction) along the X-rail 102. The Y-rails 101 are supported by the X-direction drivers 160 that are held by each Y-rail 101. The carriage 110 also includes a second Z-direction driver 140b that moves the head holder 130 in the Z direction relative to the carriage 110.

[0070] The liquid ejection device 100 ejects paint, an example of which is a liquid, from a liquid ejection head provided on a head holder 130 while moving a carriage 110 in the X-axis, Y-axis, and Z-axis directions, to draw on an object 200 onto which the liquid is to be ejected. Here, the movement of the carriage 110 and head holder 130 in the Z direction does not need to be parallel to the Z direction, and may be oblique movement as long as it includes at least a component in the Z direction. Furthermore, if the liquid ejection head has a single nozzle row, the liquid ejection head may be held on the carriage 110 so as to be tiltable with respect to the X-axis direction, making the nozzle pitch variable.

[0071] FIG. 13 is a diagram showing an example of a supply device 170 that supplies paint liquid to a plurality of liquid ejection heads 10 included in a device 100 that ejects liquid. The supply device 170 includes tanks 172a to 172d as sealed containers that contain paints 171a to 171d to be ejected from the liquid ejection heads 10a to 10d held by the head holder .

[0072] The tank 172 and the supply port 16 (see FIG. 1) of the liquid ejection head 10 are connected via a tube 173. Meanwhile, the tank 172 is connected to a compressor 176 via a pipe 175 including an air regulator 174. The compressor 176 supplies pressurized air to the tank 172. This puts the paint inside the liquid ejection head 10 into a pressurized state, and by opening the needle valve 8 described above, the paint is ejected from the nozzle 14.

[0073] In Figure 13, the surface shape of the object 200 onto which the liquid is to be ejected is shown as a flat surface, but the surface shape of the object 200 onto which the liquid is to be ejected may also be a nearly vertical surface, such as the body of a car or truck, or the body of an airplane, or a surface with a large radius of curvature.

[0074] FIG. 14 is a diagram showing an example of an electrode manufacturing apparatus 700 as an apparatus for discharging liquid, which is equipped with the liquid discharge head of this embodiment. The electrode manufacturing apparatus 700 includes a discharge process section 710 that includes a process of applying a liquid composition to a printing substrate 704 having an object to be discharged to form a liquid composition layer, and a heating process section 730 that includes a heating process of heating the liquid composition layer to obtain an electrode mixture layer.

[0075] The printing substrate 704 on which the liquid composition layer is formed is not particularly limited as long as it is an object on which a layer having an electrode material is to be formed, and can be appropriately selected depending on the purpose. For example, an electrode substrate (current collector), an active material layer, a layer having a solid electrode material, etc. can be mentioned.

[0076] Furthermore, the discharge process unit 710 may be configured to form a layer having an electrode material by directly discharging a liquid composition, as long as it is possible to form a layer having an electrode material on the printing substrate 704. Alternatively, the discharge process unit 710 may be configured to form a layer having an electrode material by indirectly discharging a liquid composition. The heating process section 730 is a process for heating the liquid composition that has been discharged onto the printing substrate 704 in the discharge process section 710. The liquid composition layer can be dried by heating.

[0077] The electrode manufacturing apparatus 700 includes a conveying section 705 that conveys the printing substrate 704, and the conveying section 705 conveys the printing substrate 704 at a preset speed through the ejection process section 710 and the heating process section 730 in that order. There are no particular limitations on the method for manufacturing the printing substrate 704 having an object to be ejected, such as an active material layer, and any known method can be selected as appropriate. The ejection process section 710 includes a printing device 281a that includes the liquid ejection head 10 of this embodiment that ejects a liquid composition onto the printing substrate 704. The apparatus also includes a storage container 281b that stores the liquid composition, and a supply tube 281c that supplies the liquid composition stored in the storage container 281b to the printing device 281a.

[0078] The storage container 281b stores the liquid composition 707, and the discharge process unit 710 discharges the liquid composition 707 from the printing device 281a and applies the liquid composition 707 onto the printing substrate 704 to form a thin film of the liquid composition layer. The storage container 281b may be configured as an integral part of the manufacturing apparatus for the electrode mixture layer, or may be configured as a removable part from the manufacturing apparatus for the electrode mixture layer. Alternatively, the storage container 281b may be a container used for adding the liquid to a storage container integrated with the manufacturing apparatus for the electrode mixture layer or a storage container removable from the manufacturing apparatus for the electrode mixture layer. Furthermore, the storage container 281b and the supply tube 281c can be arbitrarily selected as long as they can stably store and supply the liquid composition 707.

[0079] The heating process section 730 has a heating device 703 and includes a solvent removal step of heating and drying and removing the solvent remaining in the liquid composition layer with the heating device 703. This allows the formation of an electrode mixture layer. The heating process section 730 may perform the solvent removal step under reduced pressure.

[0080] The heating device 703 is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a substrate heater, an IR heater, a hot air heater, etc., and these may be combined. The heating temperature and time can be appropriately selected depending on the boiling point of the solvent contained in the liquid composition 707 and the thickness of the formed film.

[0081] When the liquid ejection head 10 of this embodiment is used in the electrode manufacturing apparatus 700, the liquid composition can be ejected to a targeted location on an object to be ejected. The electrode mixture layer can be suitably used, for example, as part of the configuration of an electrochemical element. The components other than the electrode mixture layer in the electrochemical element are not particularly limited, and known components can be appropriately selected, such as a positive electrode, a negative electrode, and a separator.

[0082] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0083] In the above description, an embodiment has been described in which the needle valve 31 is opened and closed by applying a voltage to a driver such as the piezoelectric element 32. However, the present invention is not limited to this, and the needle valve 31 may be opened and closed by air pressure or hydraulic pressure. In this case, the drive pulse generated by the drive control device is a drive waveform for driving the air- or hydraulic-based pressurizing mechanism at a set pressure.

[0084] In this application, a "liquid ejection device" refers to a device that includes a liquid ejection head or a liquid ejection unit in which functional components and mechanisms are integrated with the liquid ejection head, and that ejects liquid by driving the liquid ejection head. The above-mentioned integration includes, for example, a device in which the liquid ejection head and the functional components or mechanisms are fixed to each other by fastening, bonding, engaging, etc., or a device in which one is held movably relative to the other. The liquid ejection head and the functional components or mechanisms may also be detachable from each other.

[0085] There are liquid ejection units in which the liquid ejection head and head tank are integrated, and in which the two are integrated by being connected to each other by a tube, etc. Here, it is also possible to add a unit including a filter between the liquid ejection head and head tank of these liquid ejection units.

[0086] There are liquid ejection units in which the liquid ejection head and carriage are integrated, and liquid ejection units in which the liquid ejection head, carriage, and scanning movement mechanism are integrated, and there are liquid ejection units in which the liquid ejection head is movably held by a guide member that constitutes part of the scanning movement mechanism, and the liquid ejection head and scanning movement mechanism are integrated.

[0087] Some liquid ejection units integrate the liquid ejection head, carriage, and maintenance and recovery mechanism by fixing a cap member, which is part of the maintenance and recovery mechanism, to a carriage on which the liquid ejection head is attached. Other liquid ejection units integrate the liquid ejection head and supply mechanism by connecting a tube to the liquid ejection head, which is equipped with a head tank or flow path components. Liquid from a liquid storage source is supplied to the liquid ejection head via this tube.

[0088] The scanning movement mechanism includes the guide member alone, and the supply mechanism includes the tube alone and the loading unit alone.

[0089] The term "device for ejecting liquid" includes not only a device that can eject liquid onto an object onto which the liquid can adhere, but also a device that ejects liquid into air or liquid.

[0090] This "liquid ejection device" can also include means for feeding, transporting, and discharging items onto which liquid can be attached, as well as pre-processing devices and post-processing devices.

[0091] For example, examples of "liquid ejecting devices" include image forming devices that eject ink to form images on paper, and three-dimensional modeling devices (three-dimensional modeling devices) that eject modeling liquid onto a powder layer formed from layers of powder in order to create a three-dimensional object (a three-dimensional model).

[0092] Furthermore, the term "liquid ejection device" is not limited to devices that use ejected liquid to visualize meaningful images such as letters and figures. For example, it also includes devices that form patterns that have no meaning in themselves, and devices that create three-dimensional images.

[0093] The above-mentioned "object onto which liquid can adhere" refers to the aforementioned object onto which liquid is ejected, and means an object onto which liquid can adhere at least temporarily, an object onto which the liquid adheres and sticks, an object onto which the liquid adheres and penetrates, etc. Specific examples include media such as paper, recording paper, film, and cloth, electronic circuit boards, electronic components such as piezoelectric elements, powder layers, organ models, and test cells, and unless otherwise specified, includes all objects onto which liquid can adhere.

[0094] The material of the "substance to which a liquid can adhere" may be any material to which a liquid can adhere, even temporarily, such as paper, thread, fiber, fabric, leather, metal, plastic, glass, wood, or ceramics.

[0095] Furthermore, the "liquid ejection device" may be a device in which a head unit and an object onto which the liquid can be attached move relatively, but is not limited to this. Specific examples include a serial type device in which the head unit moves, and a line type device in which the head unit does not move.

[0096] Other examples of "liquid ejecting devices" include treatment liquid application devices that eject treatment liquid onto paper to apply the treatment liquid to the surface of the paper for purposes such as modifying the surface of the paper, and spray granulation devices that spray a composition liquid in which raw materials are dispersed through a nozzle hole to granulate fine particles of the raw materials.

[0097] Although the preferred embodiments of the present invention have been described above, the present invention is not limited to such specific embodiments, and unless otherwise specifically limited in the above description, various modifications and variations are possible within the spirit and scope of the present invention as set forth in the claims.

[0098] The above description is merely an example, and each of the following aspects provides unique effects. (Aspect 1) In a liquid ejection head 10 comprising a nozzle plate 15 in which nozzles 14 are formed, a valve member such as a needle valve 31 that opens and closes the nozzle 14, a moving means such as a piezoelectric element 32 that moves the valve member between an open position that opens the nozzle 14 and a closed position that blocks the nozzle, a casing such as a housing 11 that has a liquid chamber 17 that contains liquid to be ejected from the nozzle 14 and a moving means accommodating section such as a piezoelectric element accommodating section 330 that accommodates the moving means, and a sealing member 34 that abuts against the casing and the valve member and seals the space between the liquid chamber 17 and the moving means accommodating section, the sealing member 34 is held in the casing so as not to be able to move in the movement direction of the valve member. In Patent Document 1, the length of the retaining groove provided in the valve member in the direction of valve member movement is longer than the length of the sealing member in the direction of movement, allowing the sealing member to move within the retaining groove within a predetermined range in the movement direction. Therefore, the sealing member is slidable against both the outer circumferential surface of the valve member and the inner wall surface of the housing. Therefore, when the valve member moves to open or close, the sealing member may move together with the valve member and slide against the inner wall surface of the housing, or the valve member may move alone and slide against the sealing member, potentially changing the object against which the sealing member slides. As a result, the movement resistance of the valve member when opening or closing varies, causing variations in the amount and speed of the valve member's movement, which may result in variations in the amount and speed of droplets ejected from the nozzle. In contrast, in Aspect 1, the sealing member is held in the housing so as to be immovable in the direction of movement of the valve member, so that when the valve member moves to open or close, the sealing member slides only on the outer circumferential surface of the valve member. This makes it possible to suppress fluctuations in the movement resistance when the valve member moves to open or close, and to suppress variations in the amount and speed of movement of the valve member. This makes it possible to suppress variations in the amount and speed of droplets ejected from the nozzle.

[0099] (Aspect 2) In the first embodiment, the sealing member 34 is an elastic member, and is held by a casing such as the housing 11 at a compression ratio of 5 to 25%. This allows for good sealing, as explained in the embodiment, and also makes it possible to suppress permanent deformation of the sealing member 34.

[0100] (Aspect 3) In embodiment 1 or 2, the sealing member 34 is a molded member, and the parting line 34a of the sealing member 34 is not in contact with the valve member such as the needle valve 31 or the casing such as the housing 11, or the contact pressure of the parting line 34a with the valve member or the casing is lower than the contact pressure of the sealing portion of the sealing member 34 with the valve member and the sealing portion with the casing. As a result, as described with reference to FIG. 8, the parting line 34a of the sealing member 34 can prevent the occurrence of areas where the contact pressure between the sealing member and the mating member is low, thereby preventing localized liquid leakage.

[0101] (Aspect 4) In any of aspects 1 to 3, the sealing member 34 is annular, and a housing such as the housing 11 has an annular retaining groove 44 that holds the sealing member 34, the sealing member 34 is compressed in the movement direction (Z direction) by a pair of side surfaces of the retaining groove 44, and the inner diameter d of the bottom surface of the retaining groove 44 is equal to or greater than the outer diameter of the sealing member 34 in an uncompressed state. As a result, as described in the embodiment, the sealing member 34 can be assembled into the holding groove 44 without reducing its diameter, facilitating assembly of the sealing member 34 into the holding groove 44. Furthermore, the sealing member 34 is compressed in the movement direction (Z direction) by the side surfaces of the holding groove 44, so that the sealing member 34 abuts against the side surfaces of the holding groove 44 with a predetermined abutment pressure, thereby achieving good sealing between the sealing member 34 and the housing.

[0102] (Aspect 5) In the fourth embodiment, the outer diameter D of the valve member such as the needle valve 31 at the contact point with the sealing member 34 is shorter than the inner diameter of the sealing member in an uncompressed state. As described in the embodiment, this facilitates insertion of a valve member such as the needle valve 31 into the sealing member 34, facilitating assembly of the valve member and the sealing member. Furthermore, the sealing member 34 is compressed in the movement direction (Z direction) by the side surfaces of the retaining groove 44, and is crushed in a direction that shortens the inner diameter of the sealing member, so that the sealing member 34 can be brought into contact with the valve member to seal the gap between the valve member and the sealing member.

[0103] (Aspect 6) In any of aspects 1 to 5, a housing such as the housing 11 has a retaining groove that holds the sealing member 34, and the sealing member 34 is compressed in the movement direction by a pair of side surfaces of the retaining groove, and at least one of the pair of side surfaces of the retaining groove is inclined toward the movement direction in a cross section parallel to the movement direction. According to this, the sealing member 34 is compressed by the side surface of the retaining groove so as to collapse toward the valve member such as a needle valve, and the contact pressure with the valve member can be increased, thereby achieving good sealing.

[0104] (Aspect 7) In any of the first to sixth embodiments, at least one of the surface of the sealing member 34 and the sliding portion of the valve member such as the needle valve 31 with the sealing member 34 is coated with a low-friction material. This reduces the sliding resistance between the valve member, such as a needle valve, and the sealing member when the valve member moves.

[0105] (Aspect 8) In any one of the first to seventh aspects, the arithmetic mean roughness Ra of the housing of a valve member such as a needle valve at a sliding portion with the sealing member is 0.1 μm or less. This reduces the sliding resistance between the sealing member and the valve member when the valve member, such as a needle valve, moves.

[0106] (Aspect 9) In any of the aspects 1 to 8, the sealing member 34 is sandwiched between two members (first housing 11a and second housing 11b) that constitute a casing such as the housing 11 in the movement direction (Z direction). This allows sealing between the two components of the housing to be performed by the sealing member 34. Furthermore, after the sealing member 34 is assembled into a notch formed in one of the two components that make up the fusing, the other component can be assembled to the one component, and the sealing member 34 can be compressed in the Z direction within the holding groove 44. This eliminates the need to press the sealing member 34 into the holding groove 44 to assemble it there, making assembly of the sealing member 34 easier.

[0107] (Aspect 10) In a liquid ejection device equipped with a liquid ejection head, the liquid ejection head according to any one of the first to ninth embodiments was used as the liquid ejection head. This allows stable ejection of liquid. [Explanation of symbols]

[0108] 2: Actuator 3: Arm member 8: Needle valve 10: Liquid ejection head 11: Housing 11a: First Housing 11b: Second housing 13: Connector 14: Nozzle 15: Nozzle plate 16: Supply port 17:Liquid chamber 18: Collection port 20: Regulating member 30: Liquid dispensing module 31: Needle valve 31a: Retaining groove 32: Piezoelectric element 34: Sealing member 34a: Parting line 35: Holding body 40: Elastic member 41: Valve through hole 44: Retaining groove 53: Compression spring 54: Arm support 55: Arm member 55a: Support shaft 55b: Relief hole 55c: Fixed part 55d: Contact part 61: Moving parts 62: Arm member 62a: Support shaft 63: Leaf spring component 63a: Valve connection part 63b: Inclined part 63c: Arm connection part 100: Liquid discharging device 101: Y-axis rail 102: X-axis rail 103: Z-axis rail 110: Carriage 120: Frame unit 130: Head holder 140a: First Z-direction driving unit 140b: Second Z-direction drive unit 150: Y-direction drive unit 160: X-direction drive unit 170: Feeding device 172: Tank 173: Tube 174: Air regulator 175: Pipe 176: Compressor 200: Discharge target 330: Piezoelectric element housing 700: Electrode manufacturing equipment 703: Heating device 704: Printing base material 705: Transport unit 707 :Liquid composition 710:Discharge process section 730: Heating process section D: Outer diameter of needle valve H: Depth of the retaining groove W: Width of the retaining groove d: Inner diameter of the bottom of the retaining groove [Prior art documents] [Patent documents]

[0109] [Patent Document 1] Patent No. 7310404

Claims

1. a nozzle plate in which nozzles are formed; a valve member for opening and closing the nozzle; a moving means for moving the valve member between an open position that opens the nozzle and a closed position that closes the nozzle; a housing having a liquid chamber for accommodating the liquid to be ejected from the nozzle and a moving means accommodating section for accommodating the moving means; a sealing member that contacts the housing and the valve member and seals a gap between the liquid chamber and the moving means housing, The liquid ejection head is characterized in that the sealing member is held by the housing so as not to move in the movement direction of the valve member.

2. 2. The liquid ejection head according to claim 1, the sealing member is an elastic member, The liquid ejection head is held by the housing at a crushing ratio of 5 to 25%.

3. 2. The liquid ejection head according to claim 1, the sealing member is a molding member, A liquid ejection head characterized in that the parting line of the sealing member is not in contact with the valve member and the housing, or the contact pressure of the parting line with the valve member or the housing is lower than the contact pressure of the sealing portion of the sealing member with the valve member and the sealing portion with the housing.

4. 2. The liquid ejection head according to claim 1, the sealing member is annular, the housing has an annular holding groove for holding the sealing member, the sealing member is compressed in the movement direction by a pair of side surfaces of the holding groove; A liquid ejection head, characterized in that the inner diameter of the bottom surface of the holding groove is equal to or larger than the outer diameter of the sealing member in an uncompressed state.

5. 5. The liquid ejection head according to claim 4, A liquid ejection head, wherein the outer diameter of the valve member at the contact point with the sealing member is smaller than the inner diameter of the sealing member in an uncompressed state.

6. 2. The liquid ejection head according to claim 1, the housing has a holding groove for holding the sealing member, the sealing member is crushed in the movement direction by a pair of side surfaces of the holding groove, A liquid ejection head, wherein at least one of the pair of side surfaces of the holding groove is inclined toward the movement direction in a cross section parallel to the movement direction.

7. 2. The liquid ejection head according to claim 1, A liquid ejection head, characterized in that at least one of the surface of the sealing member and the sliding portion of the valve member with respect to the sealing member is coated with a low-friction material.

8. 2. The liquid ejection head according to claim 1, A liquid ejection head characterized in that the arithmetic mean roughness Ra of the sliding portion of the valve member against the sealing member is 0.1 μm or less.

9. 2. The liquid ejection head according to claim 1, The liquid ejection head is characterized in that the sealing member is sandwiched and held in the movement direction between two members constituting the housing.

10. In a liquid ejection device equipped with a liquid ejection head, 10. A liquid ejection device, comprising: a liquid ejection head according to claim 1;

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