Liquid discharge head and liquid discharge device

Abstract

To provide a liquid discharge head which can attach a needle leading end member to a needle rear end member with high accuracy, and to provide a liquid discharge device.SOLUTION: A liquid discharge head includes: a needle valve which opens and closes nozzles; and moving means which moves the needle valve between a closed position where the needle valve closes the nozzles and an open position where the needle valve opens the nozzles. The needle valve comprises: a needle rear end member 171 coupled to the moving means; and a needle leading end member 172 attached to the needle rear end member 171. Further, the needle valve 17 has, separately from a screw part 180 serving as axial force generating means which generates an axial force for placing the needle leading end member 172 in contact with the needle rear end member 171, a spigot part 182 serving as a shaft center restriction part which restricts a position of a shaft center of the needle leading end member 172 relative to a shaft center of the needle rear end member 171; and an inclination restriction part 183 which restricts an inclination of the needle leading end member 172 relative to the needle rear end member 171.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a liquid ejection head and an apparatus. [Background technology]

[0002] Conventionally, a liquid ejection head has been known which includes a needle valve that opens and closes a nozzle, and a moving means that moves the needle valve between a closed position that closes the nozzle and an open position that opens the nozzle, the needle valve comprising a needle rear end member connected to the moving means and a needle tip member attached to the needle rear end member.

[0003] Patent Document 1 describes a liquid ejection head in which the needle valve has a threaded portion. The threaded portion is composed of a female threaded portion provided on the needle tip member and a male threaded portion provided on the needle rear end member. The female threaded portion provided on the needle tip member is screwed onto the male threaded portion, so that the upper end surface of the needle tip member engages with the bottom surface of the needle rear end member. Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is a problem in that the accuracy of attaching the needle tip member to the needle rear end member is poor. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, the present invention provides a liquid ejection head comprising a needle valve that opens and closes a nozzle, and a moving means that moves the needle valve between a closed position that closes the nozzle and an open position that opens the nozzle, wherein the needle valve has a needle rear end member connected to the moving means and a needle tip member attached to the needle rear end member, and the needle valve has an axial force generating means that generates an axial force that causes the needle tip member to abut against the needle rear end member, and the needle valve has, separate from the axial force generating means, an axial center regulating section that regulates the position of the axial center of the needle tip member relative to the axial center of the needle rear end member, and an inclination regulating section that regulates the inclination of the needle tip member relative to the needle rear end member. [Effects of the Invention]

[0006] According to the present invention, the needle front end member can be attached to the needle rear end member with high precision. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is an overall perspective view of a liquid ejection head. [Figure 2] FIG. 2 is a schematic configuration diagram showing a head unit. [Figure 3] FIG. 1 is a schematic cross-sectional view of a liquid ejection head. [Figure 4] FIG. 2 is a schematic diagram showing the basic configuration of a liquid ejection module. [Figure 5] 5A and 5B are diagrams illustrating replacement of a needle tip member and a nozzle plate. [Figure 6] FIG. 10 is a diagram showing an example of a needle tip member to be replaced. [Figure 7] (a) is a diagram explaining a malfunction that occurs when the axial center of the needle tip member is shifted in a direction perpendicular to the Z direction relative to the axial center of the needle rear end member, and (b) is a diagram explaining a malfunction that occurs when the needle tip member is attached at an angle relative to the needle rear end member. [Figure 8]FIG. 8(a) is a diagram explaining a malfunction that occurs when the axial center of the needle tip member is deviated from the center of the nozzle when the tip shape is concave, and FIG. 8(b) is a diagram explaining a malfunction that occurs when the axial center of the needle tip member is deviated from the center of the nozzle when the tip shape is conical. [Figure 9] FIG. 4 is a schematic diagram showing the vicinity of a connection point between a needle front end member and a needle rear end member. [Figure 10] FIG. 4 is a diagram illustrating an example of dimensions of a needle valve. [Figure 11] 10A and 10B are diagrams for explaining measurement of the positional deviation of the axial center of the needle front end member relative to the axial center of the needle rear end member and the inclination of the needle front end member relative to the needle rear end member. [Figure 12] FIG. 10 is a diagram showing another example of a means for generating an axial force. [Figure 13] FIG. 10 is a schematic diagram showing an example in which a diaphragm seal is used as a sealing member for sealing between a storage portion and a flow path. [Figure 14] FIG. 10 is a schematic configuration diagram showing a first modified example of the present embodiment. [Figure 15] FIG. 10 is a schematic configuration diagram showing a second modified example of the present embodiment. [Figure 16] FIG. 10 is a schematic configuration diagram showing a third modified example of the embodiment. [Figure 17] FIG. 10 is a schematic configuration diagram showing a fourth modified example of the present embodiment. [Figure 18] 10A and 10B are diagrams showing an example of a diaphragm clamping structure of a needle valve. [Figure 19] FIG. 10 is a schematic configuration diagram showing a fifth modified example of the present embodiment. [Figure 20] FIG. 10 is a schematic diagram of a needle valve according to a fifth modified example. [Figure 21] FIG. 1 is a schematic diagram illustrating the configuration of an inkjet printer. [Figure 22] FIG. 1 is a perspective view showing an example of the placement of an inkjet printer in a vehicle. [Figure 23] FIG. 1 is a schematic perspective view showing an example of an electrode manufacturing apparatus. [Figure 24] FIG. 10 is a schematic perspective view showing another 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] Fig. 1 is an overall perspective view of a liquid ejection head 10. In Fig. 1, the longitudinal direction of the liquid ejection head 10 (the direction in which the nozzles 14 are arranged) is defined as the X direction, and the lateral direction of the liquid ejection head 10 is defined as the Y direction. The height direction of the liquid ejection head 10 (the opening and closing direction of the needle valve 17, the movement direction of the needle valve 17, and the direction in which liquid is ejected from the nozzles 14) is defined as 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 has a housing 11 that serves as a case. The housing 11 is made of metal or resin. The housing 11 is composed of a nozzle housing 11b and a main housing 11a. The main housing 11a has a connector 29 at its top for communicating electrical signals. In addition, one end of the housing 11 in the X direction has a supply port 12 for supplying liquid such as ink into the head, and the other end in the X direction has a recovery port 13 for discharging liquid from the head.

[0011] 2 is a schematic configuration diagram showing the head unit 60, and is also a cross-sectional view of the liquid ejection head 10 taken along the line AA in FIG.

[0012] The liquid ejection head 10 has a nozzle plate 15. The nozzle plate 15 is joined to the nozzle housing 11b. The nozzle plate 15 has a plurality of nozzles 14 that eject liquid arranged in the longitudinal direction (X direction) of the liquid ejection head 10. The housing 11b is provided with a liquid chamber 16 in which the liquid flows. The liquid chamber 16 is a path that sends the liquid supplied from the supply port 12 over the nozzle plate 15 to the recovery port 13. The liquid is sent over the liquid chamber 16 in the directions indicated by arrows a1 to a3 in FIG. 2.

[0013] With the above configuration, supply port 12 takes in pressurized liquid from the outside, sends the liquid in the direction of arrow a1, and supplies the liquid to liquid chamber 16. Liquid chamber 16 sends the liquid from supply port 12 in the direction of arrow a2. Then, recovery port 13 discharges liquid that has not been ejected from nozzles 14 arranged along liquid chamber 16 in the direction of arrow a3.

[0014] A plurality of liquid ejection modules 70 are arranged between the supply port 12 and the recovery port 13. The number of liquid ejection modules 70 corresponds to the number of nozzles 14, and in this example, a configuration is shown in which eight liquid ejection modules 70 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 70 are not limited to those described above. For example, the number of nozzles 14 and liquid ejection modules 70 may be one instead of multiple. The number may also be eight or more or less. The nozzles 14 and liquid ejection modules 70 may also be arranged in multiple rows instead of a single row.

[0015] Each liquid ejection module 70 includes a needle valve 17 that opens and closes the nozzle 14, and a piezoelectric element 18 that serves as an actuator that drives the needle valve 17. By displacing the piezoelectric element 18, the needle valve 17 is opened and closed, and liquid is ejected from the nozzle 14.

[0016] The housing 11 is provided with a plurality of storage sections 110 (see FIG. 3) as moving means storage sections that store the moving mechanisms 58 (see FIG. 3) of the liquid discharging module 70. Each storage section 110 is provided with a piezoelectric element regulating member 19 that regulates the position of the piezoelectric element 18 in the Z direction.

[0017] A sealing member is provided as a sealing portion at the tip of the needle valve 17. When the sealing member of the needle valve 17 is pressed against the nozzle plate 15, the sealing member is compressed, thereby reliably closing the nozzle 14 with the needle valve 17.

[0018] When a voltage is applied to the piezoelectric element 18 by the drive control device 40, the piezoelectric element 18 is displaced in the Z direction, and the needle valve 17 is pulled up in a direction away from the nozzle 14 by a movement mechanism 58, which will be described later. This causes the needle valve 17 to move away from the nozzle 14, opening the nozzle 14. This causes the liquid supplied under pressure to the liquid chamber 16 to be ejected from the nozzle 14. Furthermore, when no voltage is applied to the piezoelectric element 18, the needle valve 17 closes the nozzle 14. In this state, even if liquid is supplied under pressure to the liquid chamber 16, the liquid will not be ejected from the nozzle 14.

[0019] The drive control device 40 has a waveform generation circuit 41, which is a drive pulse generation unit, and an amplifier circuit. The waveform generation circuit generates a drive pulse waveform, which will be described later, and the amplifier circuit amplifies the voltage value to the required value. The amplified voltage is then applied to the piezoelectric element 18. By applying this voltage, the drive control device 40 controls the opening and closing of the needle valve 17, thereby controlling the ejection of liquid from the liquid ejection head 10. However, if the waveform generation circuit can apply a sufficient voltage, the amplifier circuit may be omitted.

[0020] The waveform generating circuit 41 generates a drive pulse, which is a waveform that changes over time as the voltage applied to the piezoelectric element 18 changes. The waveform generating circuit receives print data from an external PC or an internal microcomputer of the device and generates a drive pulse based on this input data. The waveform generating circuit can change the voltage applied to the piezoelectric element 18 and generate multiple drive pulses. As described above, when the waveform generating circuit generates a drive pulse, the piezoelectric element 18 expands and contracts in accordance with the drive pulse, opening and closing the needle valve 17.

[0021] FIG. 3 is a schematic cross-sectional view of the liquid ejection head 10 taken along a plane perpendicular to the X direction. The nozzle housing 11b has a liquid chamber 16 and holds a nozzle plate 15. The main body housing 11a has a plurality of housing portions 110 that house the movement mechanisms 58 of the liquid ejection module .

[0022] A pin fitting hole 111a is formed in the top of the nozzle housing 11b, and a positioning pin 112 is fitted into the pin fitting hole 111a. A positioning hole 111b is formed in the underside of the main body housing 11a. The nozzle housing 11b is positioned relative to the main body housing 11a by inserting the positioning pin 112 fitted into the pin fitting hole 111a of the nozzle housing 11b into the positioning hole 111b of the main body housing 11a. The nozzle housing 11b is fastened to the main body housing 11a with screws.

[0023] The liquid ejection module 70 has a needle valve 17 that opens and closes the nozzle 14, as well as a movement mechanism 58 that serves as a movement means and includes a piezoelectric element 18. The piezoelectric element 18 is held by a holder 63.

[0024] A protrusion 63a is provided on the base end side of the holder 63, which is opposite to the nozzle 14 side, and this protrusion 63a is fitted into a recess in the piezoelectric element restricting member 19. The piezoelectric element restricting member 19 has a screw hole extending in the Y direction. A positioning screw 42 is screwed into this screw hole from outside the main body housing 11a.

[0025] The positioning screw 42 is inserted into a slot that is long in the Z direction and formed in the upper end of the main body housing 11a. Therefore, the positioning screw 42 can move a predetermined distance in the Z direction. The positioning screw 42 is tightened while positioning the piezoelectric element restricting member 19 in the Z direction. This fixes the upper part of the piezoelectric element 18 so that it cannot move.

[0026] The needle valve 17 is composed of two members: a needle tip member 172 that seals the nozzle 14, and a needle rear end member 171 whose upper end is fixed to the leaf spring member 30 of the movement mechanism 58. Two bearings 113 that support the needle rear end member 171 are provided at a predetermined distance in the Z direction (the up-down direction, which is also the liquid discharge direction) on the nozzle side of the accommodating section 110 of the main body housing 11a. The needle rear end member 171 is held by the two bearings 113 in an attitude parallel to the Z direction and is movable parallel to the Z direction. The needle tip member 172 holds an O-ring 22 that serves as a seal member for sealing between the accommodating portion 110 and the liquid chamber 16 .

[0027] FIG. 4 is a schematic diagram showing the basic configuration of the liquid ejection module 70. As shown in FIG. FIG. 4(a) is a schematic diagram showing the state in which the needle valve 17 closes the nozzle 14, and FIG. 4(b) is a schematic diagram showing the state in which the needle valve 17 opens the nozzle 14. The liquid ejection module 70 includes a needle valve 17 serving as a valve member for opening and closing the nozzle 14, and a movement mechanism 58. In addition to the piezoelectric element 18, the movement mechanism 58 includes a movement member 20, a pair of arm members 21, and a leaf spring member 30. One end of the movement member 20 is fixed to the piezoelectric element 18, and the pair of arm members 21 are rotatably attached to the other end, and are attached to a holder 63 that holds the piezoelectric element 18 so as to be movable in the Z direction. The pair of arm members 21 are rotatably supported by a support shaft 21a attached to the holder 63.

[0028] The leaf spring member 30 is formed by bending a stainless steel sheet metal to form a valve connection portion 31 connected to the needle valve 17, a pair of inclined portions 32 as elastic deformation portions, and a pair of arm connection portions 33. The needle valve 17 is bonded to the valve connection portion 31 with an adhesive, and the inclined portions 32 as elastic deformation portions extend diagonally upward in the figure from both ends of the valve connection portion 31. The arm connection portions 33 are attached to the arm member 21 by being fitted into slit portions provided in the arm member 21.

[0029] 4(a), when the needle valve 17 closes the nozzle 14 (when the needle valve 17 is in the closed position), the pair of inclined portions 32 of the leaf spring member 30 elastically deform as shown by the dashed lines in the figure, thereby generating an urging force that presses the needle valve 17 against the nozzle plate 15.

[0030] As shown by the black arrow in FIG. 4(b), the piezoelectric element 18 is displaced toward the nozzle 14, causing the moving member 20 to move toward the nozzle and push the pair of arm members 21 toward the nozzle. This causes the pair of arm members 21 to rotate around the support shaft 21a as a fulcrum. As the pair of arm members 21 rotate, both ends of the leaf spring member 30 move in directions away from each other. This lifts the needle valve 17, opening the nozzle 14 and causing liquid to be ejected from the nozzle 14 (this corresponds to a state in which the needle valve 17 is in the open position that opens the nozzle 14).

[0031] Because the needle valve 17 and nozzle plate 15 repeatedly come into contact with and separate from each other, the needle tip, which is the contact point between the needle tip member 172 and the nozzle plate 15, and the contact point between the nozzle plate 15 and the needle valve 17, become worn or dirty over repeated use. As a result, the discharge condition deteriorates or a seal failure occurs, causing liquid to ooze out of the nozzle 14. For this reason, the needle tip member 172 and the nozzle plate 15 need to be replaced periodically.

[0032] FIG. 5 is a diagram illustrating replacement of the needle tip member 172 and the nozzle plate 15. As shown in FIG. First, the nozzle housing 11b that holds the nozzle plate 15 fastened to the main body housing 11a with screws is removed to expose the needle tip member 172 of the needle valve 17. Next, the needle tip member 172 with a worn tip is removed from the needle rear end member 171 and replaced with a new needle tip member 172.

[0033] The O-ring 22, which serves as a seal between the accommodation portion 110 and the liquid chamber 16, slides against the inner wall surface of the nozzle housing 11b and wears when the needle valve 17 opens and closes. By holding the O-ring 22 on the needle tip member 172, the worn O-ring 22 can be replaced with a new one along with the needle tip member 172. This ensures a good seal between the accommodation portion 110 and the liquid chamber 16 over time, effectively preventing the liquid in the liquid chamber 16 from leaking into the accommodation portion 110.

[0034] After replacing with a new needle tip member 172, the nozzle housing 11b holding the new nozzle plate 15 is positioned in the main body housing 11a by the positioning pins 112. The nozzle plate 15 is then replaced by fastening it to the main body housing 11a with screws. The nozzle plate 15 may be configured to be removable from the nozzle housing 11b, for example, by fastening it to the nozzle housing 11b with screws, so that only the nozzle plate 15 is replaced.

[0035] Furthermore, the housing 11 may be configured as a single member having the liquid chamber 16 and the storage portion 110, and the nozzle plate 15 may be configured to be detachable from the housing. Specifically, after the positioning pins of the nozzle plate 15 are inserted into the positioning holes of the housing to position it, the nozzle plate 15 is fastened to the housing with screws.

[0036] Furthermore, the optimal tip shape and tip material of the needle valve 17 for achieving good sealing vary depending on the type and viscosity of the liquid to be discharged, the proportion of solids such as fillers contained in the liquid, the shape and size of the solids, and the like. The optimal tip shape of the needle valve 17 also varies depending on the discharge amount. In this embodiment, the needle valve 17 is made up of two components, a needle tip member 172 and a needle rear end member 171, and the needle tip member 172 is configured to be easily replaceable. This makes it easy to change to a needle tip member 172 with a different tip shape. By changing the needle tip member 172 depending on the type and viscosity of the liquid to be discharged, the proportion of solids such as fillers contained in the liquid, the shape and size of the solids, and the discharge amount, the nozzle 14 can be sealed well and the target discharge amount can be achieved.

[0037] FIG. 6 shows an example of a needle tip member 172 to be replaced. Fig. 6(a) shows a needle tip component 172 with a conical tip, and Fig. 6(b) shows a needle tip component 172 with a ball fitted into the tip. Fig. 6(c) shows a needle tip component 172 with a sealing member 173 made of an elastic material such as resin or rubber attached to the tip and with a flat tip shape (underside of sealing member 173). Fig. 6(d) shows a needle tip component 172 with a sealing member 173 made of an elastic material such as resin or rubber attached to the tip and with a concave tip shape.

[0038] A needle tip member 172 with a conical tip as shown in Fig. 6(a) or a needle tip member 172 with a spherical tip as shown in Fig. 6(b) contacts the edge or inner peripheral surface of the nozzle 14 to remove and seal solids contained in the liquid. A needle tip member 172 provided with a sealing member 173 made of an elastic material as shown in Fig. 6(c) or 6(d) elastically deforms the sealing member 173 to prevent non-contact areas caused by solids in the liquid that could not be removed from the sealed area between the nozzle 14 and the tip of the needle valve 17.

[0039] The user attaches to the needle rear end member 171 a needle tip member 172 with a tip shape and tip material that can adequately seal the nozzle 14, based on the type of liquid to be discharged, viscosity, solid content such as filler contained in the liquid, shape and size of the solid content, discharge amount, etc. This makes it possible to handle a variety of liquids.

[0040] Furthermore, depending on the type of liquid to be discharged, its viscosity, the proportion of solids such as fillers contained in the liquid, the shape and size of the solids, etc., it may be better to seal the nozzle 14 by closely fitting the tip of the needle valve 17 to the edge of the nozzle 14, as shown in Figure 6(a). Also, as shown in Figure 6(b), it may be better to seal the nozzle 14 by matching the shape of the needle valve side of the nozzle 14 to the shape of the tip of the needle valve 17 and closely fitting the tip of the needle valve 17 to the inner peripheral surface of the nozzle. There is also an optimal nozzle diameter depending on the discharge amount.

[0041] In this embodiment, the nozzle plate 15 is also replaceable, and a combination of the needle tip member 172 and the nozzle plate (nozzle) that can provide good sealing can be selected depending on the liquid to be ejected. This makes it possible to accommodate an even greater variety of liquids.

[0042] However, configuring the needle valve 17 from two members, the needle tip member 172 and the needle rear end member 171, and configuring the needle tip member 172 to be easily replaceable may result in the following problems: That is, there is a problem that, due to an attachment error, the needle tip member 172 may be attached to the needle rear end member 171 with a large deviation in the position perpendicular to the Z direction between the axial center position of the needle tip member 172 and the axial center position of the needle rear end member 171. There is also a problem that the needle tip member 172 may be attached at an angle relative to the needle rear end member 171.

[0043] Fig. 7(a) is a diagram illustrating a malfunction that occurs when the axial center of the needle tip member 172 is shifted in a direction perpendicular to the Z direction relative to the axial center of the needle rear end member 171. Fig. 7(b) is a diagram illustrating a malfunction that occurs when the needle tip member 172 is attached at an angle relative to the needle rear end member 171.

[0044] If the axial center of the needle tip member 172 shifts in a direction perpendicular to the Z direction relative to the axial center of the needle rear end member 171, there is a risk that the position of the axial center O2 of the needle tip member 172 will shift relative to the center O1 of the nozzle 14, as shown in Figure 7(a).

[0045] When the axial center O2 of the needle tip member 172 is misaligned with the center O1 of the nozzle 14, the distance from the nozzle 14 to the end of the needle tip becomes uneven, as shown by B1 and B2 in FIG. 7(a). This causes uneven fluid resistance immediately after the start of ejection or immediately before the end of ejection when the gap between the needle valve tip and the nozzle periphery is narrow. As a result, as shown in FIG. 7(a), there is a risk of the liquid ejected from the nozzle 14 becoming curved (discharge deflection). Another problem is poor liquid cutoff. Furthermore, when discharge deflection occurs, the pitch of the droplets varies during continuous liquid ejection, which can result in streaks or other issues in the image.

[0046] Furthermore, as shown in Figure 7(b), if the needle tip component 172 is attached at an angle relative to the needle rear end component 171, the gap between the needle valve tip and the periphery of the nozzle becomes uneven, as shown by G1 and G2. As a result, just as in Figure 7(a), when the gap between the needle valve tip and the periphery of the nozzle is narrow immediately after the start of discharge or just before the end of discharge, the fluid resistance becomes uneven. Therefore, even if the needle tip component 172 is attached at an angle relative to the needle rear end component 171, problems such as bent discharge and poor liquid cut-off occur.

[0047] 8(a), when the tip of the needle tip member 172 is concave, problems such as deflected discharge due to the difference in distance from the nozzle 14 to the end of the needle tip caused by a misalignment between the center O1 of the nozzle 14 and the axial center O2 of the needle tip member 172 are reduced. However, there is a risk of disturbances occurring in the discharge of liquid in the recessed portion of the needle tip when closing the needle valve 17. In addition, there is a risk that some of the liquid will remain in the recessed portion of the needle tip, causing the liquid to flow down from the nozzle 14 after the discharge operation is completed.

[0048] Also, as shown in FIG. 8(b), even when the tip of the needle tip member 172 is conical, if the position of the axial center O2 of the needle tip member 172 is misaligned with the center O1 of the nozzle 14, there is a risk of discharge bending occurring when closing.

[0049] 7, the concave shape shown in FIG. 8(a), or the conical shape shown in FIG. 8(b), if the needle tip member 172 is attached at an angle to the needle rear end member 171, there will be a location where the contact pressure between the needle tip and the nozzle 14 or the nozzle plate 15 is low. As a result, there is a risk of liquid leaking from the nozzle 14. Therefore, it is necessary to attach the needle tip member 172 to the needle rear end member 171 with high precision.

[0050] FIG. 9 is a schematic diagram showing the vicinity of the connection point between the needle front end member 172 and the needle rear end member 171. As shown in FIG. As shown in FIG. 9, the needle valve 17 has a threaded portion 180, which is an attachment portion for attaching the needle tip member 172 to the needle rear end member 171 and also serves as an axial force generating means for generating an axial force, a spigot portion 182, which is an axial center regulating portion, and an inclination regulating portion 183.

[0051] The threaded portion 180 is made up of a female threaded portion 180a provided on the needle rear end member 171 and a male threaded portion 180b provided on the needle tip member 172. The needle tip member 172 is attached to the needle rear end member 171 by fastening the male threaded portion 180b to the female threaded portion 180a.

[0052] The spigot portion 182 is composed of a cylindrical fitting hole 182a provided in the needle rear end member 171 and a columnar fitting portion 182b provided in the needle tip member 172. By fitting the needle tip member 172 into the fitting hole 182a of the needle rear end member 171, the axial center of the needle tip member 172 is precisely regulated with respect to the axial center of the needle rear end member 171.

[0053] The inclination regulating portion 183 is the lower end surface of the needle rear end member 171 and is composed of a first seating surface 183a perpendicular to the Z direction and a second seating surface 183b perpendicular to the Z direction that extends radially from the lower end of the fitting portion 182b of the needle tip member 172. By bringing the second seating surface 183b into close contact with the first seating surface 183a, the inclination of the needle tip member 172 relative to the needle rear end member 171 is regulated with high precision.

[0054] Figure 10 is a diagram illustrating an example of the dimensions of the needle valve 17, where Figure 10(a) is a schematic cross-sectional view of the entire needle valve 17, and Figure 10(b) is an enlarged view of the upper side of the needle tip member 172 (the rear end side of the needle tip member 172).

[0055] 10 has a diameter of 1.3 mm, and the screw portion 180 is a micro screw with a screw size of S0.8. The diameter of the needle valve 17 is the diameter when a valve jet type liquid ejection head having a nozzle array has a minimum mountable nozzle pitch of 2 mm.

[0056] If the inner diameter of the nozzle 14 on the needle valve side is 0.3 mm, the needle tip member shown in Figure 6(d) is used as the needle tip member, and the inner diameter of the tip recess is 0.5 mm, the deviation between the nozzle center and the axial center of the tip of the needle valve 17 must be kept to 50 μm or less.

[0057] In addition to the accuracy of attachment of the needle front end member 172 to the needle rear end member 171, the following factors can cause misalignment between the nozzle center and the center of the tip of the needle valve. These include the joining accuracy of the nozzle plate 15 to the nozzle housing 11b (30 μm) and the assembly accuracy of the needle rear end member 171 to the main body housing 11a (the restriction accuracy of the bearing portion 113 that receives the needle rear end member 171) (24.5 μm). In addition, there is a center misalignment error (19.8 μm) when forming the recess at the needle tip, and the positioning accuracy (19.6 μm) when attaching the nozzle housing 11b to the main body housing 11a. The cumulative tolerance (root sum of squares) of the misalignment between the nozzle center and the center of the tip of the needle valve 17 due to these factors is √(30 2 +24.5 2 +19.8 2 +19.6 2 ) = 47.7 (μm). Therefore, in order to make the deviation between the nozzle center and the center of the tip of the needle valve 17 50 μm or less, the deviation between the nozzle center and the center of the tip of the needle valve 17, which is caused by the accuracy of attachment of the needle tip member 172 to the needle rear end member 171, is 15 μm (√(50 2 -47.7 2 In this embodiment, by providing the spigot portion 182 and the tilt regulating portion 183, the misalignment between the nozzle center and the center of the tip of the needle valve 17, which is caused by the accuracy of attachment of the needle tip member 172 to the needle rear end member 171, can be reduced to 15 μm or less.

[0058] Specifically, the outer diameter of the fitting portion 182b of the spigot portion 182 is set to 0.9 mm, and the inner diameter of the fitting hole 182a of the spigot portion 182 is set to be approximately 1 to 5 μm larger than the outer diameter of the fitting portion 182b. As a result, the axial center of the needle front end member 172 is regulated with an accuracy of 5 μm or less relative to the axial center of the needle rear end member 171. The height (length in the Z direction) of the spigot portion 182 is 1 mm. The outer peripheral surface of the fitting portion 182b and the inner peripheral surface of the fitting hole 182a are simply arc surfaces, and the outer diameter of the fitting portion 182b and the inner diameter of the fitting hole can be easily machined with high accuracy by cutting. Therefore, the gap between the fitting hole 182a and the fitting portion 182b can be formed with an accuracy of 5 μm or less.

[0059] Furthermore, the perpendicularity of the first seating surface 183a and the second seating surface 183b of the tilt regulating portion 183 with respect to the Z direction is set to 2 μm or less. As a result, when the second seating surface 183b is in close contact with the first seating surface 183a, the tilt of the needle front end member 172 with respect to the needle rear end member 171 is regulated to 5 minutes (0.083°) or less. The first seating surface 183a and the second seating surface 183b are flat surfaces perpendicular to the Z direction. Therefore, the first seating surface 183a and the second seating surface 183b can be easily formed with a perpendicularity precision of 2 μm or less by cutting, polishing, or the like.

[0060] 10(a), in the case of the following dimensions, when the needle tip component 172 is tilted by 5 minutes (0.083°) or less with respect to the needle rear end component 171, the deviation between the center of the needle tip and the axial center of the needle rear end component is 10 μm or less. That is, when the length from the second seating surface 183b of the needle tip component 172 to the needle tip (the lower end of the needle main end component) is 7 mm, and the outer diameter of the needle tip is 1 mm.

[0061] When the axial center offset at the spigot portion 182 is adjusted, the maximum offset between the center of the needle tip and the axial center of the needle rear end member is 15 μm. This makes it possible to keep the offset between the center of the nozzle and the center of the tip of the needle valve 17 to 50 μm or less, thereby preventing deflection of the discharge or poor discharge completion due to the offset between the center of the nozzle and the center of the tip of the needle valve 17.

[0062] Incidentally, by making the inner diameter of the fitting hole 182a of the spigot portion 182 larger than the outer diameter of the fitting portion 182b by approximately 1 to 5 μm, the needle tip member 172 can move and tilt within a predetermined range relative to the needle rear end member 171. As a result, when the tilt is regulated by the tilt regulating portion 183, the needle tip member 172 moves relative to the needle rear end member 171 to correct the tilt, and the tilt of the needle tip member 172 relative to the needle rear end member 171 is precisely regulated by the tilt regulating portion 183.

[0063] By controlling the tightening torque of the threaded portion 180, which is a microscrew with a thread size of S0.8, to 0.9 to 1 cN·m, an axial force of approximately 50 to 60 N is generated. This allows the axial force generated by the threaded portion 180 to bring the second bearing surface 183b into good contact with the first bearing surface 183a of the tilt restricting portion 183. This allows the tilt restricting portion 183 to precisely restrict the tilt of the needle front end member 172 relative to the needle rear end member 171.

[0064] Here, the state in which the second seating surface 183b is in close contact with the first seating surface 183a refers to a stable state in which the surface roughness and minute irregularities of the seating surfaces 183a and 183b become smooth due to the axial force, and the seating surfaces are in contact with each other at at least three contact points. The friction between the seating surfaces generated by this axial force prevents the threaded portion 180 from loosening due to the load caused by the opening and closing operation of the needle valve. This prevents the axial force from decreasing, releasing the close contact between the first seating surface 183a and the second seating surface 183b, and preventing the inclination from being accurately regulated.

[0065] Furthermore, by using the tilt regulating unit 183 to restrict the tilt of the needle tip member 172 relative to the needle rear end member 171 to 5 minutes (0.083°) or less, the difference in height of the needle tip (difference in position in the Z direction) can be restricted to 2 μm or less when the diameter of the needle tip is 1 mm. As explained in FIG. 7(b), a height difference exceeding approximately 5 μm can cause deflected discharge or poor sealing due to unevenness in the gap between the needle valve tip and the nozzle periphery. Therefore, by restricting the tilt of the needle tip member 172 relative to the needle rear end member 171 to 5 minutes (0.083°) or less, the difference in height of the ends of the needle tip in the direction perpendicular to the Z direction can be restricted to 5 μm or less, effectively suppressing deflected discharge and poor sealing due to the height difference.

[0066] As described with reference to FIG. 8(a), a concave needle tip shape is less affected by the difference in distance from the nozzle 14 to the end of the needle tip, which is caused by a misalignment between the center O1 of the nozzle 14 and the axial center O2 of the needle tip member 172. Therefore, a misalignment of up to 15 μm between the center O1 of the nozzle 14 and the axial center O2 of the needle tip member 172 can be tolerated. However, as shown in FIG. 7(a), if the tip shape of the needle valve is such that a difference in distance from the nozzle 14 to the end of the needle tip, which is caused by a misalignment between the center O1 of the nozzle 14 and the axial center O2 of the needle tip member 172, is significantly affected, it is necessary to further reduce the misalignment. Furthermore, some needle valve tip shapes are less affected by the difference in distance from the nozzle 14 to the end of the needle tip than the tip shape shown in FIG. 8(a), and some can tolerate a greater degree of misalignment. Therefore, the squareness of the second seating surface 183b and the outer diameter of the fitting portion 182b (the gap with the fitting hole 182a) are set appropriately according to the shape of the tip of the needle valve 17.

[0067] FIG. 11 is a diagram illustrating measurement of the positional deviation of the axial center of the needle tip member 172 from the axial center of the needle rear end member 171 and the inclination of the needle tip member 172 with respect to the needle rear end member 171. In FIG. The contact point of the needle rear end member 171 with the bearing portion 113 is chucked, and the needle valve 17 is rotated around the axial center of the needle rear end member 171. Then, a microgauge is placed on the point indicated by arrow A1 in the figure to measure the runout of the second seating surface 183b. Then, the amount of positional deviation of the axial center of the needle tip member 172 from the axial center of the needle rear end member 171 can be calculated from the measured runout amount and rotation angle information.

[0068] The inclination of the needle tip member 172 relative to the needle rear end member 171 is measured by placing a microgauge on the second seating surface 183b indicated by arrow A1 in the figure and on the needle tip portion indicated by arrow A2 in the figure, and measuring the amount of runout. Then, the inclination of the needle tip member 172 relative to the needle rear end member 171 can be measured from the amount of runout and the rotation angle information.

[0069] The threaded portion 180, which is the axial force generating means, also has a certain degree of centering function by tightening the screw depending on the angle of the threads, and the axial center of the needle tip member can be aligned to a certain extent with the axial center of the needle rear end member. However, even with a high-grade, high-precision threaded portion 180, the effect is limited, and it is difficult to achieve positioning on the micron level. In addition, misalignment can occur due to the balance of friction generated when the bearing surfaces come into contact and the balance of force during tightening.

[0070] In this embodiment, in addition to the screw portion 180, there is provided a spigot portion 182 that regulates the axial center of the needle tip member 172 relative to the axial center of the needle rear end member 171, and an inclination regulation portion 183 that regulates the inclination of the needle tip member 172 relative to the needle rear end member 171.

[0071] The inner peripheral surface of the fitting hole 182a of the spigot portion 182 and the outer peripheral surface of the fitting portion 182b are both arcuate surfaces, and the inner diameter of the fitting hole 182a and the outer diameter of the fitting portion 182b can be formed with high precision by simple processing such as cutting. Furthermore, the seating surfaces 183a, 183b of the tilt regulating portion 183 are flat, and therefore can be formed with high precision by simple processing such as cutting. This allows for high-precision attachment with an inexpensive configuration. Furthermore, the thread intersection can be a standard thread intersection, allowing the needle tip member 172 to be easily attached to and detached from the needle rear end member 171, and the needle tip member 172 to be easily replaced.

[0072] Five samples were prepared for each of a needle valve according to the present embodiment and a comparative example having only the tilt restricting portion 183 without the spigot portion 182 in the needle valve having the dimensional relationship shown in FIG. 10 . The deviation between the center O1 of the nozzle 14 and the axial center O2 of the needle tip member 172 was measured three times for each sample (a total of 15 measurements). The average value ± standard deviation (3σ) of the deviation between the center O1 of the nozzle 14 and the axial center O2 of the needle tip member 172 in the comparative example was 60 ± 40 μm. On the other hand, the average value ± standard deviation (3σ) of the deviation between the center O1 of the nozzle 14 and the axial center O2 of the needle tip member 172 in the present embodiment was 4 ± 9 μm. In the comparative example without the inlay portion 182, the deviation between the center O1 of the nozzle 14 and the axial center O2 of the needle tip member 172 was approximately 100 μm at most (99.7% probability), whereas in this embodiment, the deviation was approximately 13 μm at most (99.7% probability), which was able to be kept to 15 μm or less.

[0073] Even in the comparative example without the spigot portion 182, the inclination of the needle tip member 172 relative to the needle rear end member 171 is restricted by the inclination restriction portion 183, and the inclination of the needle tip member 172 is restricted to the same extent as in this embodiment (5 minutes or less, 0.083° or less). Therefore, the deviation between the center of the needle tip and the center of the nozzle due to the inclination of the needle tip member 172 is 10 μm or less.

[0074] Meanwhile, in the comparative example, the axial center of the needle tip member 172 relative to the axial center of the needle rear end member 171 is regulated by the above-mentioned centering function of the threaded portion 180. However, the centering function of the threaded portion 180 makes it difficult to achieve positioning on the order of microns, and in the comparative example, the average value ± standard deviation (3σ) of the deviation between the center O1 of the nozzle 14 and the axial center O2 of the needle tip member 172 was 40 ± 60 μm.

[0075] On the other hand, in this embodiment, the fitting portion 182 has a spigot portion 182 with a gap of 5 μm or less between the fitting portion 182b and the fitting hole 182a. This enables positioning on the micron level, and the misalignment between the center O1 of the nozzle 14 and the axial center O2 of the needle tip member 172, which is caused by the misalignment of the axial center of the needle rear end member 171 with respect to the axial center of the needle tip member 172, can be kept to 5 μm or less. As a result, in this embodiment having the spigot portion 182, the average value ± standard deviation (3σ) of the misalignment between the center O1 of the nozzle 14 and the axial center O2 of the needle tip member 172 was 4 ± 9 μm, which was able to be kept to 15 μm or less.

[0076] Incidentally, by forming the spigot portion 182 with precision and configuring the fitting portion 182b to fit tightly into the fitting hole 182a, the spigot portion 182 can also precisely regulate the inclination of the needle tip member 172 relative to the needle rear end member 171. However, in order to precisely regulate the inclination with the spigot portion 182, it is necessary to lengthen the length of the spigot portion 182 in the Z direction to some extent so that the fitting portion 182b can be press-fitted into the fitting hole 182a. As a result, a large axial force is required to screw the needle tip member 172 to the needle rear end member 171 while press-fitting the fitting portion 182b into the fitting hole 182a. If the diameter of the needle valve 17 is small, it is difficult to generate a large axial force in the threaded portion 180, making installation difficult. Furthermore, repeated attachment and detachment causes the inner peripheral surface of the fitting hole 182a to wear and the diameter to expand, making it difficult to accurately regulate the inclination with the spigot portion 182 over time.

[0077] In this embodiment, by providing the tilt regulation portion 183 separately from the spigot portion 182, the fitting portion 182b can be loosely fitted into the fitting hole 182a, and the needle tip member 172 can be easily attached to the needle rear end member 171. In addition, the tilt of the needle tip member 172 relative to the needle rear end member 171 can be continuously and accurately regulated.

[0078] Furthermore, the axial force generating means for generating the axial force is not limited to the threaded portion 180. For example, as shown in FIG. 12(a), a configuration may be adopted in which the needle tip member is attached to the needle rear end member 171 using a heat-shrinkable tube 184 used for insulating and protecting electric wires. In the configuration shown in FIG. 12(a), the outer periphery of the rear end side (upper end side) of the needle tip member 172 and the outer periphery of the tip side (lower end side) of the needle rear end member 171 are tapered so that the outer diameter increases toward the end. These tapered structures are covered with a heat-shrinkable tube 184, and hot air is applied to the heat-shrinkable tube 184. This causes the heat-shrinkable tube 184 to shrink in the Z direction, generating an axial force that presses the needle tip member 172 against the needle rear end member 171. This allows the bearing surfaces of the tilt restriction portions 183 to be in close contact with each other.

[0079] Alternatively, as shown in FIG. 12(b), a configuration may be adopted in which an axial force is generated by magnetic force to attach the needle tip member 172 to the needle rear end member 171. As shown in FIG. 12(b), a magnet 185 is attached to a recess on the tip side (lower end side) of the needle rear end member 171, and the needle tip member 172, which is made of a magnetic material such as metal, is attracted by the magnetic force of the magnet 185. This generates an axial force that presses the needle tip member 172 against the needle rear end member 171, allowing the seating surfaces of the tilt regulating portion 183 to closely contact each other. Preferably, the magnet 185 is arranged so as not to come into contact with the rear end (upper end) of the needle tip member 172, and the magnet 185 regulates the position of the needle tip member 172 in the vertical direction (Z direction) to prevent the seating surfaces from not closely contacting each other. Alternatively, a configuration in which a magnet is provided on the needle tip member 172 may be adopted.

[0080] 12(c), the needle tip member 172 may be attached to the needle rear end member 171 by generating an axial force using a bayonet lock structure. The bayonet lock structure 186 has an engagement pin 186a provided on the needle rear end member 171 and a lock groove 186b provided on the needle rear end member 171. The lock groove 186b consists of a guide groove 186b1 extending straight in the Z direction from the rear end (upper end) of the needle tip member 172, and a cam groove 186b2 inclined with respect to the Z direction. The engagement pin 186a provided on the needle rear end member 171 is inserted to the lower end of the guide groove 186b1 of the lock groove 186b. Next, the needle tip member 172 is rotated while being pushed into the needle rear end member 171, and the engagement pin 186a is engaged with the cam groove 186b2. By engaging the engaging pin 186a with the cam groove 186b2, an axial force is generated that presses the needle tip member 172 against the needle rear end member 171, and the seating surfaces of the tilt regulating portion 183 can be brought into close contact with each other.

[0081] FIG. 13 is a schematic diagram showing an example in which a diaphragm seal 122 is used as a sealing member for sealing between the accommodating portion 110 and the liquid chamber 16. In FIG. The diaphragm seal 122 has a hole in the center through which the needle valve 17 passes, the edge of this hole is fixed to the needle valve 17, and the outer end is clamped and fixed between the main body housing 11a and the nozzle housing 11b to seal the space between the storage section 110 and the liquid chamber 16.

[0082] The diaphragm seal 122 may crack or break due to fatigue caused by repeated use as it elastically deforms in the vertical direction in response to the opening and closing movement of the needle valve 17. For this reason, the diaphragm seal 122 is also preferably configured to be held by the needle tip member 172 and replaced together with the needle tip member 172, as shown in Figure 13(b).

[0083] [Variation 1] FIG. 14 is a schematic diagram showing a first modified example of this embodiment. In this first modification, the fitting portion 182b of the needle tip member 172 has a two-stage configuration consisting of an introduction portion 182b1 and a final fitting portion 182b2 having a larger outer diameter than the introduction portion 182b1. In this modification 1, the outer diameter of the introduction portion 182b1 is made smaller than the inner diameter of the fitting hole 182a by about 5 to 10 μm, while the outer diameter of the final fitting portion 182b2 is larger than the inner diameter of the fitting hole 182a by about 1 to 2 μm.

[0084] The gap between introduction portion 182b1 and fitting hole 182a is 5 μm to 10 μm, which is larger than the gap (1 to 5 μm) between fitting portion 182b and fitting hole 182a in the present embodiment shown in Fig. 10. This makes it easier to insert fitting portion 182b into fitting hole 182a than in the embodiment, improving the workability of attaching needle tip member 172.

[0085] Furthermore, the outer diameter of the final fitting portion 182b2 is larger than the inner diameter of the fitting hole 182a by about 1 to 2 μm, and the final fitting portion 182b2 is lightly press-fitted into the fitting hole 182a. This allows the axial center of the needle rear end member 171 to be approximately aligned with the axial center of the needle front end member 172. Furthermore, the light press-fitting makes the threaded portion 180 less likely to loosen.

[0086] In this first modification, once the male thread portion 180b of the needle front end member 172 is threaded to a certain extent into the female thread portion 180a of the needle rear end member 171, the final fitting portion 182b2 of the fitting portion 182b is lightly press-fitted into the fitting hole 182a. The Z-direction length of the final fitting portion 182b2 is 100 to 150 μm, assuming that the inner diameter of the fitting hole 182a is 0.9 mm and the thread size of the threaded portion 180 is S0.8, which is a microscrew configuration. Immediately after the final fitting portion 182b2 of the fitting portion 182b is lightly press-fitted into the fitting hole 182a, the second seating surface 183b of the tilt restricting portion 183 immediately comes into close contact with the first seating surface 183a, completing the screw tightening. In this way, because the final fitting portion 182b2 is lightly press-fitted into the fitting hole 182a in the final stage of screw tightening, only force is required for screw tightening in the final stage of screw tightening. This makes it possible to easily attach the needle tip member 172 to the needle rear end member 171.

[0087] Furthermore, the final fitting portion 182b2 only slightly fits into the lower end of the fitting hole 182a, and this final fitting portion 182b2 alone cannot accurately regulate the inclination of the needle tip member 172 relative to the needle rear end member 171. Therefore, in the first modification, by providing an inclination regulation portion 183 in addition to the spigot portion 182, the inclination of the needle tip member 172 relative to the needle rear end member 171 can be accurately regulated.

[0088] [Variation 2] FIG. 15 is a schematic diagram showing a second modified example of this embodiment. 15, in this second modified example, the needle valve 17 has a threaded portion 180, which serves as both an attachment portion and an axial force generating means, and a tapered portion 181. The tapered portion 181 precisely regulates the axial center of the needle tip member 172 relative to the axial center of the needle rear end member 171, and also precisely regulates the inclination of the needle tip member 172 relative to the needle rear end member 171. In other words, the tapered portion 181 is configured to function as both an axial center regulating portion and an inclination regulating portion.

[0089] 15, the tapered portion 181 has a first tapered surface portion 181a provided on the needle rear end member 171 and a second tapered surface portion 181b provided on the needle tip member 172. The first tapered surface portion 181a has a generally mortar shape with an inner diameter that widens downward (toward the nozzle), and the second tapered surface portion 181b has a generally conical shape with an outer diameter that widens downward.

[0090] When the male screw portion 180b of the needle tip member 172 is screwed into the female screw portion 180a of the needle rear end member 171, the second tapered surface portion 181b comes into close contact with the first tapered surface portion 181a. By the second tapered surface portion 181b coming into close contact with the first tapered surface portion 181a, the axial center of the needle tip member 172 is precisely regulated with respect to the axial center of the needle rear end member 171. Furthermore, the inclination of the needle tip member 172 with respect to the needle rear end member 171 is precisely regulated.

[0091] In this modified example 2, compared to the configuration having the spigot portion 182 of the embodiment, the needle tip member 172 (the portion where the male thread portion 180b and the second tapered surface portion 181b are formed) can be easily inserted into the recess (the portion where the female thread portion 180a and the first tapered surface portion 181a are formed) provided on the tip side of the needle rear end member 171. The first tapered surface portion 181a can guide the male thread portion 180b into the female thread portion 180a. This makes it easy to attach the needle tip member 172 to the needle rear end member 171.

[0092] Furthermore, compared to the first modification in which the axial center of the needle tip member 172 is precisely regulated relative to the axial center of the needle rear end member 171 by light press-fitting, damage (wear and distortion) to the needle valve 17 can be suppressed. This makes it possible to suppress a decrease in regulation accuracy due to repeated attachment and detachment of the needle tip member 172. Furthermore, because each tapered surface portion 181a, 181b is a surface inclined with respect to the Z direction, dirt adhering to the tapered surface portions can easily fall off. Therefore, compared to a modification in which seating surfaces perpendicular to the Z direction are brought into close contact with each other to precisely regulate tilt, there are also advantages in that the precision of tilt regulation is less likely to be reduced due to the adhesion of dirt, and dirt can be easily removed by cleaning.

[0093] On the other hand, the configuration of the embodiment in which the spigot portion 182 and the tilt regulating portion 183 are provided has the advantage that high accuracy can be achieved with simpler processing than the tapered portion, and manufacturing costs can be reduced.

[0094] [Variation 3] FIG. 16 is a schematic diagram showing a third modified example of this embodiment. As shown in Fig. 16, in Modification 3, a seal portion 187b that seals between the storage portion 110 and the liquid chamber 16 and a seal portion 187a that seals the nozzle 14 are integrally molded on the needle tip member 172. The seal portion 187b of the needle tip member 172 shown in Fig. 16(a) is an O-ring type that abuts on the inner wall surface of the housing 11 and slides against the inner wall surface of the housing. On the other hand, the seal portion 187b in Fig. 16(b) is a diaphragm type whose end is sandwiched between the main body housing 11a and the nozzle housing 11b.

[0095] The seal portion 187b and the sealing portion 187a are molded integrally with the needle tip member by insert molding rubber and resin with the metal body of the needle tip member 172 as a core. By molding the seal portion 187b integrally with the body of the needle tip member 172, the center of the seal portion 187b can be aligned with the center of the needle tip member 172 with high precision, ensuring uniform contact pressure with the inner wall surface of the housing. This reduces variations in sliding resistance with the inner wall surface of the housing and variations in elastic deformation of the seal portion, allowing the needle valve to be opened and closed smoothly and ensuring good sealing between the needle valve and the inner wall surface of the housing.

[0096] 6(a) and 6(b), the seal portion 187b that seals between the storage portion 110 and the liquid chamber 16 may be integrally molded by insert molding into the main body of the needle tip member 172. Even in this case, it is possible to suppress variations in the sliding resistance with the inner wall surface of the housing and variations in the elastic deformation of the seal portion.

[0097] However, when the nozzle is sealed with the main body of the needle tip member made of metal, wear at the needle tip progresses more slowly than wear at the seal portion made of rubber or resin. Therefore, for needle tip members that do not have a seal portion made of rubber or resin at the needle tip, it is preferable to have a configuration that holds the O-ring 22 and diaphragm seal 122 so that only the O-ring 22 and diaphragm seal 122 can be replaced.

[0098] [Variation 4] FIG. 17 is a schematic diagram showing a fourth modified example of this embodiment. As shown in Figure 17, in this fourth modification, a diaphragm seal 122 that seals between the accommodating portion 110 and the liquid chamber 16 is attached to the lower end of the main body housing 11a. The edge of the hole in the diaphragm seal 122 through which the needle valve 17 passes is clamped and fixed between a needle tip member 172 and a needle rear end member 171. This allows the edge of the hole in the diaphragm seal 122 through which the needle valve 17 passes to be fixed to the needle valve when the needle tip member 172 is attached to the needle rear end member 171. This makes it easy to fix the diaphragm seal 122 to the needle valve 17.

[0099] 18(a) and 18(b) are diagrams showing an example of a diaphragm clamping structure of the needle valve 17. FIG. In FIG. 18(a), a ring-shaped notch 188a is provided at the end of the first seating surface 183a of the needle rear end member 171, and a ring-shaped protrusion 188b is provided at the end of the second seating surface 183b of the needle front end member 172.

[0100] The edge of the hole in the diaphragm seal 122 through which the needle valve 17 passes is positioned in the notch 188a at the end of the first seating surface 183a, thereby regulating the position of the hole through which the needle valve 17 passes in the diaphragm seal 122. Then, as shown in the right-hand drawing of Figure 18(a), when the needle tip member 172 is attached to the needle rear end member 171, the ring-shaped protrusion 188b crushes the edge of the hole in the diaphragm seal 122 through which the needle valve 17 passes. As a result, the edge of the hole in the diaphragm seal 122 through which the needle valve 17 passes is clamped and fixed between the needle tip member 172 and the needle rear end member 171, thereby providing a seal.

[0101] In Figure 18(b), a ring-shaped washer 188c is used to crush the edge of the hole in the diaphragm seal 122 through which the needle valve 17 passes, and the edge of the hole is clamped between the needle tip member 172 and the needle rear end member 171 via the washer 188c to seal it.

[0102] In the configuration shown in Figure 18(a), when the needle tip component 172 is attached to the needle rear end component 171 by screwing, the protrusion 188b rotates together with the needle tip component 172. As a result, a rotational force is applied to the diaphragm seal 122, which may cause the diaphragm seal 122 to twist. On the other hand, as shown in Figure 18(b), by using a washer 188c, it is possible to prevent the washer 188c from rotating together with the needle tip component 172 when the needle tip component 172 is screwed. This makes it possible to prevent the diaphragm seal 122 from twisting.

[0103] [Variation 5] FIG. 19 is a schematic diagram showing a fifth modified example of this embodiment. As shown in FIG. 19, in the fifth modification, the connection point between the needle tip member 172 and the needle rear end member 171 is positioned inside the liquid chamber 16. 19, the length of the needle tip member 172 can be shortened by configuring the connection point between the needle tip member 172 and the needle rear end member 171 to be located inside the liquid chamber 16. This makes it possible to suppress misalignment between the axial center of the needle tip and the center of the nozzle 14 when the needle tip member 172 is tilted relative to the needle rear end member 171.

[0104] FIG. 20 is a schematic diagram of the needle valve 17 in the configuration of the fifth modification. As shown in Figure 20, the needle rear end member 171 holds an O-ring 22 that seals the gap between the liquid chamber 16 and the storage portion 110. A ring-shaped notch is formed at the end of the second seating surface 183b of the needle tip member 172, and a valve connection seal member (O-ring) 189 is held in this notch. When the needle tip member 172 is attached (screwed) to the needle rear end member 171, the valve connection seal member 189 comes into contact with and is crushed against the first seating surface 183a of the needle rear end member 171. As a result, the connection point between the needle tip member 172 and the needle rear end member 171 is sealed by the valve connection seal member 189.

[0105] In this way, the connection point between the needle tip member 172 and the needle rear end member 171 is sealed by the valve connection seal member 189, thereby preventing the liquid in the liquid chamber 16 from entering the threaded portion 180, the spigot portion 182, and the tilt regulating portion 183. This makes it possible to suppress contamination of the threaded portion 180, the spigot portion 182, and the tilt regulating portion 183, and allows the needle tip member 172 to be easily attached to and detached from the needle rear end member 171.

[0106] 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.

[0107] An example of a liquid ejection device having the above-described liquid ejection head 10 will now be described.

[0108] FIG. 21 is a schematic diagram of an inkjet printer 810 as a device for discharging liquid, and FIG. 22 is a perspective view showing an example of the placement of the inkjet printer 810 relative to an automobile U1. 21, an inkjet printer 810 includes a liquid ejection unit 100 having a liquid ejection head, and a camera 812 serving as an image capturing means disposed near the liquid ejection unit 100. The inkjet printer 810 also includes an XY table 811 serving as a scanning movement mechanism that moves the liquid ejection unit 100 and the camera 812 in the X and Y directions.

[0109] The inkjet printer 810 also includes a control unit 600. The control unit 600 operates the XY table 811 based on image editing software S that edits images captured by the camera 812 and a preset control program to eject ink from the liquid ejection unit 100 and control printing on a surface to be printed. The inkjet printer 810 also includes a drive unit 620 that positions the camera 812 and the liquid ejection unit 100 at predetermined positions based on control from the control unit 600 and performs operations of capturing images and printing.

[0110] The liquid ejection unit 100 is equipped with multiple liquid ejection heads that eject ink toward the surface of an automobile U1 (see FIG. 22) that serves as the object to be coated. Note that "ink" here also includes "paint." The nozzle surfaces of the liquid ejection heads are parallel to the XY plane formed by the movement of the XY table 811, and ink dots ejected from each nozzle are ejected in the Z direction, which is perpendicular to the XY plane.

[0111] The liquid ejection unit 100 has a plurality of liquid ejection heads, each connected to an ink tank of a predetermined color, which is pressurized by a pressure device. Ink from the ink tank is supplied from a supply port 12 (see FIG. 1) of the liquid ejection head and discharged from a recovery port 13 (see FIG. 1) of the liquid ejection head. The ink discharged from the recovery port 13 is recovered into the ink tank.

[0112] If the distance between the nozzle surface of the liquid ejection head and the print surface of the car U1 is about 20 cm, ink dots can be ejected onto the print surface of the car U1 without any problems.

[0113] The XY table 811 is provided with a Y-axis rail 813 formed with a linear movement mechanism, and an X-axis movement mechanism 814 that moves the Y-axis rail 813 in the X direction while holding the Y-axis rail 813 with two arms.

[0114] The liquid discharge unit 100 and a camera 812, which will be described later, are attached to a slider held by a Y-axis rail 813. A shaft 815 is provided on the X-axis movement mechanism 814, and this shaft 815 is held by a robot arm 816. This robot arm allows the liquid discharge unit 100 to be freely positioned at a predetermined position on the automobile U1 where printing is to be performed.

[0115] For example, the robot arm 816 can be placed above the vehicle U1 as shown in Fig. 22(a) or to the side of the vehicle U1 as shown in Fig. 22(b). The operation of the robot arm 816 is controlled based on a program stored in advance in the control unit 600.

[0116] The camera 812 is mounted on a slider on a Y-axis rail 813 near the liquid discharge unit 100 and moves in the X and Y directions while capturing images of a predetermined range of the surface to be printed on the automobile U1 at constant, minute intervals. The camera 812 is a so-called digital camera, and as described above, the specifications of the lens, resolution, etc. that enable capturing multiple sub-divided images of the predetermined range of the surface to be printed are appropriately selected. The capturing of the multiple sub-divided images of the surface to be printed by the camera 812 is performed continuously and automatically according to a program pre-installed in the control unit 600.

[0117] The control unit 600 includes a storage device that records and saves various programs, data on captured images and data on images to be printed, and a central processing unit that executes various processes in accordance with the programs. The control unit 600 is also configured as a so-called microcomputer that includes input devices such as a keyboard and a mouse, and a DVD player, etc., if necessary.

[0118] In addition, the inkjet printer 810 further includes a monitor 610, which displays information input to the control unit 600, the results of processing by the control unit 600, and the like. As will be described later, the control unit 600 uses image processing software to process the multiple pieces of subdivided image data captured by the camera 812, and generates a composite print surface by projecting the non-flat print surface of the automobile U1 onto a flat surface. The control unit 600 also edits the image to be drawn as follows to generate the edited image to be drawn. That is, the image to be drawn, which is an image to be printed so as to be continuous with the image already printed on the print surface, is superimposed on the composite print surface, and the image to be drawn is edited so as to be continuous with the edge of the already printed image.

[0119] For example, an edited image to be drawn is generated by editing (deforming) the image to be drawn so that it fits into the composite print surface so that no non-print area is formed between adjacent images to be drawn. Then, based on this edited image to be drawn, printing is actually performed by the liquid ejection unit 100. This makes it possible to print a print image with no gaps between already printed print images. Note that the photographing of multiple subdivided images by the camera 812 and the printing by ejecting ink from the nozzles of each liquid ejection head of the liquid ejection unit 100 are performed by the drive unit 620, whose operation is controlled by the control unit 600.

[0120] Next, an electrode manufacturing apparatus will be described as another example of an apparatus for discharging liquid that includes the liquid discharge head of this embodiment.

[0121] FIG. 23 is a schematic perspective view showing an example of an electrode manufacturing apparatus 850. As shown in FIG. 23 is an apparatus for manufacturing negative electrodes used in electrochemical elements such as primary batteries, secondary batteries, capacitors, condensers, etc. The electrode manufacturing apparatus 850 is equipped with a liquid discharge unit 852 having the liquid discharge head 10 of this embodiment, and discharges liquid onto a negative electrode substrate U4 on a stage 851 using an inkjet method.

[0122] Liquid tank 853 contains liquid composition D 1 for forming negative electrode composite material layer 855 , and liquid composition D 1 is supplied from liquid tank 853 to liquid discharge unit 852 via tube 854 .

[0123] FIG. 24 is a schematic perspective view showing another example of an electrode manufacturing apparatus 850. As shown in FIG. 24, an electrode manufacturing apparatus 850 winds a strip-shaped negative electrode substrate U4 made of stainless steel, copper, or the like around a cylindrical core, and loads the electrode substrate U4 between a feed roller 857 and a take-up roller 859 with the surface on which the negative electrode composite layer 855 is to be formed facing upward. The feed roller 857 and the take-up roller 859 rotate counterclockwise, and the negative electrode substrate U4 moves from right to left in the drawing.

[0124] Liquid tank 853 contains liquid composition D1 for forming negative electrode composite layer 855, and supplies liquid composition D1 from liquid tank 853 to liquid discharge unit 852 via tube 854. Liquid discharge unit 852 is installed above negative electrode substrate U4 between delivery roller 857 and take-up roller 859. Furthermore, a plurality of liquid discharge units 852 may be installed in a direction substantially parallel to or substantially perpendicular to the transport direction of negative electrode substrate U4.

[0125] A delivery roller 857 and a take-up roller 859 transport the negative electrode substrate U4 carrying the liquid composition D1 to a drying device 858. As a result, the liquid composition D1 on the negative electrode substrate U4 is dried by the drying device 858 to form a negative electrode mixture layer 855, and a negative electrode 856 is formed in which the negative electrode mixture layer 855 is bonded to the negative electrode substrate serving as the negative electrode substrate U4. Thereafter, the negative electrode 856 is cut to a desired size by punching or the like.

[0126] The drying device 858 is not particularly limited as long as it does not come into direct contact with the liquid composition D1, and can be selected appropriately. Examples include a resistance heater, an infrared heater, and a fan heater. The drying device 858 may be installed either above or below the negative electrode substrate U4. Furthermore, multiple drying devices 858 may be installed.

[0127] While the above description has been given as an example of an apparatus for manufacturing a negative electrode for use in an electrochemical element, it is of course also applicable to an apparatus for manufacturing a positive electrode. When manufacturing a positive electrode, the electrode substrate for a negative electrode is replaced with an electrode substrate for a positive electrode, and liquid composition D1 for forming negative electrode composite layer 855 is replaced with a liquid composition for forming a positive electrode composite layer. Furthermore, the components other than the electrode composite 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.

[0128] Alternatively, an external tank may be provided and a valve may be controlled so that when the liquid composition D1 in the liquid tank 853 decreases, the liquid composition D1 is supplied from the external tank 860 to the liquid tank 853.

[0129] 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.

[0130] In the above description, an embodiment has been described in which the needle valve 17 is opened and closed by the piezoelectric element 18. However, the present invention is not limited to this, and the needle valve 17 may be opened and closed by air pressure or hydraulic pressure. In this case, the drive pulse generated by the drive control device 40 is a drive waveform for driving the air pressure or hydraulic pressure pressurizing mechanism at a set pressure.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] 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.

[0135] The scanning movement mechanism includes the guide member alone, and the supply mechanism includes the tube alone and the loading unit alone.

[0136] 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.

[0137] 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.

[0138] 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).

[0139] 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.

[0140] 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.

[0141] 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.

[0142] 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.

[0143] 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.

[0144] The above description is merely an example, and each of the following aspects provides unique effects. (Aspect 1) The needle valve 17 is provided with a needle valve that opens and closes the nozzle 14, and a moving means such as a moving mechanism 58 that moves the needle valve 17 between a closed position that closes the nozzle 14 and an open position that opens the nozzle 14. The needle valve 17 is a liquid ejection head consisting of a needle rear end member 171 connected to the moving means and a needle tip member 172 attached to the needle rear end member 171, and has an axial force generating means such as a screw portion 180 that generates an axial force that causes the needle tip member 172 to abut against the needle rear end member 171. In addition to the axial force generating means, the needle valve 17 has an axial center regulating portion such as a spigot portion 182 that regulates the position of the axial center of the needle tip member 172 relative to the axial center of the needle rear end member 171, and an inclination regulating portion 183 that regulates the inclination of the needle tip member 172 relative to the needle rear end member 171. By generating an axial force using an axial force generating means such as a threaded portion 180 to bring the needle tip member 172 into contact with the needle rear end member 171, the needle tip member 172 can be attached to the needle rear end member 171 without any play. For example, the threaded portion described in Patent Document 1 can be used as the axial force generating means, and the threaded portion can be tightened to generate an axial force, thereby attaching the needle tip member to the needle rear end member without any play. However, it is difficult to precisely machine the crest / valley shape and pitch of the threaded portion. As a result, the axial center of the needle tip member may be significantly misaligned in a direction perpendicular to the axial direction relative to the axial center of the needle rear end member, or the needle tip member may be tilted relative to the needle rear end member. As such, the screw portion, which serves as the axial force generating means, cannot accurately regulate the position of the axial center of the needle tip member relative to the axial center of the needle rear end member, or the inclination of the needle tip member relative to the needle rear end member, resulting in poor attachment accuracy of the needle tip member to the needle rear end member. In contrast, in aspect 1, an axial center restricting unit that restricts the position of the axial center of the needle tip member relative to the axial center of the needle rear end member and an inclination restricting unit that restricts the inclination of the needle tip member relative to the needle rear end member are provided separately from the axial force generating means. In this way, by providing these restricting units separately from the axial force generating means, which has a complex shape, such as a thread shape, that is difficult to achieve precision in order to generate axial force, the axial center restricting unit and the inclination restricting unit can be formed into shapes that are easy to achieve precision, such as arcuate or flat surfaces, and the position of the needle rear end member relative to the axial center and the inclination of the needle tip member relative to the needle rear end member can be precisely restricted during installation. This allows the needle tip member to be precisely installed on the needle rear end member.

[0145] (Aspect 2) In aspect 1, the tilt regulating portion 183 is provided on the needle rear end member 171 and comprises a first seating surface 183a that is perpendicular to the axial direction of the needle rear end member 171, and a second seating surface 183b that is provided on the needle tip member 172 and is perpendicular to the axial direction of the needle tip member 172, and the second seating surface 183b is brought into close contact with the first seating surface 183a by an axial force generated by an axial force generating means such as the threaded portion 180. As described in the embodiment, this allows the second seating surface 183b and the first seating surface 183a to be flat, and their perpendicularity to an axial direction such as the Z direction can be precisely achieved by cutting or the like. By closely fitting the second seating surface 183b to the first seating surface 183a, the inclination of the needle tip member 172 relative to the needle rear end member can be precisely restricted. This allows the needle tip member 172 to be attached while effectively suppressing inclination relative to the needle rear end member, and suppresses misalignment between the center of the needle valve tip and the center of the nozzle. This effectively suppresses sealing failures of bent discharge nozzles.

[0146] (Aspect 3) In the first or second embodiment, the axial center regulating portion such as the spigot portion 182 is composed of a fitting hole 182a provided in the needle rear end member 171 and a fitting portion 182b provided in the needle front end member 172 and fitted into the fitting hole 182a. According to this, as described in the embodiment, the inner diameter dimension of the fitting hole 182a and the outer diameter dimension of the fitting portion can be easily formed with high precision by cutting work, etc. As a result, by fitting the fitting portion 182b into the fitting hole 182a, the axial center of the needle front end member can be precisely regulated with respect to the axial center of the needle rear end member.

[0147] (Aspect 4) In the third aspect, the fitting portion 182b has an introduction portion 182b1 whose outer diameter is smaller than the inner diameter of the fitting hole 182a, and a final fitting portion 182b2 whose outer diameter is larger than the inner diameter of the fitting hole 182a. As described in variant example 1, by having the introduction portion 182b1 whose outer diameter is shorter than the inner diameter of the fitting hole 182a, it becomes easier to fit the fitting portion 182b into the fitting hole 182a, thereby improving the ease of attaching the needle tip member 172 to the needle rear end member 171. Furthermore, by having a final fitting portion 182b2 whose outer diameter is longer than the inner diameter of the fitting hole 182a, the final fitting portion 182b2 is press-fitted into the fitting hole 182a. This allows the axial center of the needle tip member to be precisely aligned with the axial center of the needle rear end member. Furthermore, because only the final press-fitting is performed, deterioration in the workability of attaching the needle tip member 172 to the needle rear end member 171 can be suppressed.

[0148] (Aspect 5) In aspect 1, the needle rear end member 171 and the needle tip member 172 have tapered surface portions 181a, 181b that serve as both an axial center regulating portion and an inclination regulating portion, which widen as they approach the nozzle side in a cross section parallel to the axial direction of the needle valve 17, and the axial force generated by an axial force generating means such as the screw portion 180 causes tapered surface portions such as the second tapered surface portion 181b of the needle tip member 172 to adhere to tapered surface portions such as the first tapered surface portion 181a of the needle rear end member 171. As a result, as described in variant example 2, by closely adhering a tapered surface portion such as the second tapered surface portion 181b of the needle tip member 172 to a tapered surface portion such as the first tapered surface portion 181a of the needle rear end member 171, the inclination of the needle tip member and the axial center of the needle tip member can be precisely regulated.

[0149] (Aspect 6) In any of aspects 1 to 5, the needle tip member 172 holds a sealing member such as an O-ring 22 that seals between the liquid chamber 16 that contains the liquid to be ejected from the nozzle 14 and a moving means housing section such as the housing section 110 that houses a moving means such as the moving mechanism 58. As a result, as described in the embodiment, when the needle valve 17 opens and closes, sealing members such as the O-ring 22 that have worn out due to sliding against the inner surface of the housing or other enclosure can be replaced together with the needle tip member 172.

[0150] (Aspect 7) In the sixth embodiment, the sealing member such as the O-ring 22 is held closer to the tip of the needle valve 17 than the axial center restricting portion such as the spigot portion 182 and the tilt restricting portion 183 . This prevents the liquid in the liquid chamber from entering the axial center regulating portion such as the spigot portion 182 and the tilt regulating portion 183, thereby preventing a decrease in accuracy due to contamination by the liquid. It also prevents adhesion due to the liquid, making it easy to remove the needle front end member from the needle rear end member.

[0151] (Aspect 8) In any of aspects 1 to 7, a sealing portion that seals between the liquid chamber 16 that contains the liquid to be ejected from the nozzle 14 and a moving means accommodating portion such as the accommodating portion 110 that accommodates a moving means such as the moving mechanism 58 is integrally molded into the main body of the needle tip member 172. This allows the center of the needle tip member body and the center of the seal to be aligned with high precision, as explained in Modification 3, and makes the contact pressure of the seal with the housing uniform, thereby reducing sliding resistance between the seal and the housing and variations in deformation of the seal member.

[0152] (Aspect 9) In any of aspects 1 to 5, the end is fixed to a housing such as the housing 11, has a through hole through which the needle valve 17 passes, the edge of the through hole is fixed to the needle valve 17, and is provided with a diaphragm seal 122 that seals between the liquid chamber 16 and a moving means accommodating section such as the accommodating section 110 that accommodates a moving means such as the moving mechanism 58, and the edge of the through hole of the diaphragm seal 122 is clamped and fixed between the needle tip member 172 and the needle rear end member 171. As a result, as described in variant example 4, when attaching the needle tip member 172 to the needle rear end member 171, the edge of the hole in the diaphragm seal 122 through which the needle valve 17 passes can be fixed to the needle valve 17, making it easy to fix the diaphragm seal 122 to the needle valve 17. Furthermore, the edge of the through hole of the diaphragm seal 122 can be clamped and fixed with a simple structure as shown in FIGS. 18(a) and 18(b).

[0153] (Aspect 10) In any of aspects 1 to 5, the connection between the needle tip member 172 and the needle rear end member 171 is located within the liquid chamber 16 that contains the liquid to be ejected from the nozzle 14, and a sealing member such as a valve connection seal member 189 that seals the connection is provided. This allows the length of the needle valve in the axial direction (Z direction) of the needle tip member 172 to be shorter than when the connection portion between the needle tip member 172 and the needle rear end member 171 is located in a moving means housing portion such as the housing portion 110 that houses a moving means such as the moving mechanism 58, as described in Modification 5. This makes it possible to suppress misalignment between the axial center of the needle tip and the center of the nozzle due to the inclination of the needle tip member relative to the needle rear end member. Furthermore, sealing members such as valve connection sealing member 189 can prevent liquid from entering attachment parts such as threaded portion 180, axial center restricting parts such as spigot portion 182, and tilt restricting part 183, thereby preventing a decrease in accuracy due to contamination by liquid. Also, adhesion due to liquid can be prevented, and the needle front end member can be easily removed from the needle rear end member.

[0154] (Aspect 11) In any of aspects 1 to 10, the member equipped with the nozzle 14 (in this embodiment, composed of the nozzle plate 15 and the nozzle housing 11b) is configured to be detachable from the main body casing such as the main body housing 11a. As described in the embodiment, by removing the component equipped with the nozzle 14 (in this embodiment, consisting of the nozzle plate 15 and the nozzle housing 11b) from the main body housing 11a, the needle tip component is exposed, making it easy to replace the needle tip component. Furthermore, depending on the liquid to be discharged, it is possible to combine the needle tip member 172, which is capable of providing good sealing, with a member (nozzle) that is equipped with a nozzle, thereby making it possible to handle a variety of liquids.

[0155] (Aspect 12) In any of the first to eleventh embodiments, the axial force generating means is a screw structure, a magnet, a shrink tube, or a bayonet structure. This allows for the generation of axial force as described in the embodiment.

[0156] (Aspect 13) In a liquid ejection device equipped with a liquid ejection head 10, the liquid ejection head according to any one of the embodiments 1 to 13 was used as the liquid ejection head 10. This allows the nozzle to be sealed well over time and is compatible with a variety of liquids. [Explanation of symbols]

[0157] 10: Liquid ejection head 11: Housing 11a: Main body housing 11b: Nozzle housing 12: Supply port 13: Collection port 14: Nozzle 15: Nozzle plate 16:Liquid chamber 17: Needle valve 18: Piezoelectric element 19: Piezoelectric element control member 20: Moving member 21: Arm member 21a: Support shaft 22: O-ring 29: Connector 30: Leaf spring material 31: Valve connection part 32: Inclined part 33: Arm connection part 40: Drive control device 41: Waveform generating circuit 42: Positioning screw 58: Movement mechanism 60: Head unit 63: Holder 63a:Protrusion 70: Liquid dispensing module 100: Liquid discharge unit 110: Storage unit 111a: Pin fitting hole 111b: Positioning hole 112: Locating pin 113: Bearing part 122: Diaphragm seal 128a: Fitting hole 171: Needle rear end member 172: Needle tip member 173: Sealing member 180: Threaded part 180a: Female thread 180b: Male thread part 181: Tapered section 181a: First tapered surface portion 181b: Second tapered surface portion 182: Inlay part 182a: Fitting hole 182b: Fitting part 182b1 :Introduction 182b2:Final mating part 183: Tilt control part 183b:Second seat 184: Heat shrink tubing 185: Magnet 186: Mounting part 186a: Engagement pin 186b: Lock groove 186b1: Guide groove 186b2: Cam groove 187a: Sealing part 187b: Seal part 188a: Notch 188b:Protrusion 188c: Washer 189: Valve connection seal member 810: Inkjet printer 850: Electrode manufacturing equipment O1: Center of nozzle O2: Center of the needle valve tip axis [Prior art documents] [Patent documents]

[0158] [Patent Document 1] Patent No. 3247123

Claims

1. a needle valve for opening and closing the nozzle; a moving means for moving the needle valve between a closed position for closing the nozzle and an open position for opening the nozzle; the needle valve is a liquid ejection head including a needle rear end member connected to the moving means and a needle front end member attached to the needle rear end member, an axial force generating means for generating an axial force that causes the needle front end member to abut against the needle rear end member; The liquid ejection head is characterized in that the needle valve has, in addition to the axial force generating means, an axial center regulating section that regulates the position of the axial center of the needle tip member relative to the axial center of the needle rear end member, and an inclination regulating section that regulates the inclination of the needle tip member relative to the needle rear end member.

2. 2. The liquid ejection head according to claim 1, the inclination regulating portion is provided on the needle rear end member and includes a first seating surface perpendicular to the axial direction of the needle rear end member, and a second seating surface is provided on the needle front end member and perpendicular to the axial direction of the needle front end member, The liquid ejection head is characterized in that the second seating surface is brought into close contact with the first seating surface by the axial force generated by the axial force generating means.

3. 2. The liquid ejection head according to claim 1, The liquid ejection head is characterized in that the axial center regulating portion comprises a fitting hole provided in the needle rear end member, and a fitting portion provided in the needle front end member that fits into the fitting hole.

4. 4. The liquid ejection head according to claim 3, The liquid ejection head is characterized in that the fitting portion has an introduction portion having an outer diameter smaller than the inner diameter of the fitting hole, and a final fitting portion having an outer diameter larger than the inner diameter of the fitting hole.

5. 2. The liquid ejection head according to claim 1, the needle rear end member and the needle front end member have tapered surface portions that function as both the axial center restricting portion and the inclination restricting portion, the tapered surface portions widening toward the nozzle in a cross section parallel to the axial direction of the needle valve; a liquid ejection head configured to cause the tapered surface of the needle tip member to come into close contact with the tapered surface of the needle rear end member by the axial force generated by the axial force generating means;

6. 2. The liquid ejection head according to claim 1, The liquid ejection head is characterized in that the needle tip member holds a seal member that seals between a liquid chamber that contains the liquid to be ejected from the nozzle and a moving means housing portion that houses the moving means.

7. 7. The liquid ejection head according to claim 6, The liquid ejection head is characterized in that the seal member is held on the tip side of the needle valve relative to the axis center regulating portion and the tilt regulating portion.

8. 2. The liquid ejection head according to claim 1, A liquid ejection head characterized in that a sealing member that seals between a liquid chamber that contains the liquid to be ejected from the nozzle and a moving means housing that houses the moving means is integrally molded into the main body of the needle tip member.

9. 2. The liquid ejection head according to claim 1, a diaphragm seal having an end fixed to a housing, a through hole through which the needle valve passes, an edge of the through hole fixed to the needle valve, and providing a seal between a liquid chamber that contains the liquid to be ejected from the nozzle and a moving means housing that houses the moving means; The liquid ejection head according to claim 1, wherein the edge of the through hole of the diaphragm seal is clamped and fixed between the needle front end member and the needle rear end member.

10. 2. The liquid ejection head according to claim 1, a connecting portion between the needle front end member and the needle rear end member is located within a liquid chamber that contains the liquid to be ejected from the nozzle; The liquid ejection head further comprises a seal member for sealing the connection portion.

11. 2. The liquid ejection head according to claim 1, A liquid ejection head characterized in that a member having the nozzle is configured to be detachable from a main body housing.

12. 2. The liquid ejection head according to claim 1, The liquid ejection head is characterized in that the axial force generating means is a screw structure, a magnet, a shrink tube, or a bayonet structure.

13. 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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