Liquid discharge head and liquid discharge apparatus

Abstract

To provide a liquid discharge head which can position a nozzle plate and a passage member accurately.SOLUTION: A positioning pin 140 serves as a positioning member which is inserted into a main reference positioning hole 130a of a nozzle plate 101 and a positioning hole 131a of a lower housing 10b serving as a passage member to position the nozzle plate 101 on the lower housing 10b. The positioning pin is inserted, forming a predetermined gap, into the positioning hole 130a of the nozzle plate and a positioning hole 131a of the lower housing 10b. The positioning pin 140 is fixedly sandwiched between a fixture member 160a and an inner peripheral surface of the positioning hole 131a of the lower housing 10b in an attitude parallel to a Z direction.SELECTED DRAWING: Figure 7

Description

[Technical Field]

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

[0002] Conventionally, a liquid ejection head is known that includes a nozzle plate having nozzles, a flow path member having a flow path through which liquid ejected from the nozzles flows, and a positioning member that is inserted into a positioning hole in the nozzle plate and a positioning hole in the flow path member to position the nozzle plate on the flow path member, and the nozzle plate is joined to the flow path member.

[0003] Patent Document 1 describes a liquid ejection head in which a nozzle plate is joined to a housing in a state where the nozzle plate is positioned in the housing by inserting a positioning pin as a positioning member into a positioning hole in the housing as a flow path member and a positioning hole in the nozzle plate. The nozzle plate is joined to the housing by diffusion bonding, and a pressure of 20 MPa or more is applied to the interface between the housing and the nozzle plate, and a vacuum of 1.0 x 10 -4 After heating to 800°C to 1000°C, the temperature is maintained for 10 minutes to 1 hour to bond the materials. Summary of the Invention [Problem to be solved by the invention]

[0004] However, there is a problem with the accuracy of positioning the nozzle plate and the flow path member such as the housing. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, the present invention provides a liquid ejection head comprising a nozzle plate having nozzles, a flow path member having a flow path through which liquid ejected from the nozzles flows, and a positioning member that is inserted into a positioning hole in the nozzle plate and a positioning hole in the flow path member to position the nozzle plate on the flow path member, wherein the positioning member has a predetermined gap with respect to both the positioning hole in the nozzle plate and the positioning hole in the flow path member, and a fixing member is provided that pushes the positioning member from a direction perpendicular to the insertion direction of the positioning member into the positioning hole, abutting the outer surface of the positioning member against the inner surface of at least one of two positioning holes, thereby fixing the positioning member within the positioning hole in an attitude parallel to the insertion direction. [Effects of the Invention]

[0006] According to the present invention, the nozzle plate and the flow path member can be positioned with high precision. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a front view of the liquid ejection head according to the embodiment. [Figure 2] FIG. 2 is a perspective view of the liquid ejection head as viewed obliquely from below. [Figure 3] FIG. 2 is a front view of the liquid ejection head with the lower housing removed. [Figure 4] FIG. 4 is an enlarged perspective view of the lower end portion of the liquid ejection head with the lower housing removed. [Figure 5] FIG. 3 is a cross-sectional view of the liquid ejection head taken along a plane perpendicular to the X direction. [Figure 6] FIG. 4A is a cross-sectional view of the liquid ejection head taken along a line perpendicular to the Y direction, and FIG. 4B is a diagram showing the flow of liquid within a flow path. [Figure 7] 5A to 5C are diagrams illustrating a positioning structure between a nozzle plate and a lower housing in the first embodiment. [Figure 8] Diffusion bonding process flow diagram. [Figure 9] Schematic diagram of a diffusion bonding apparatus. [Figure 10]FIG. 10 is a diagram illustrating a conventional problem. [Figure 11] FIG. 10 is a bottom view of the nozzle plate in the second embodiment. [Figure 12] FIG. 10 is a schematic diagram showing the configuration of a third embodiment. [Figure 13] FIG. 10 is a schematic diagram showing the configuration of a fourth embodiment. [Figure 14] FIG. 10 is a schematic diagram showing the configuration of Comparative Example 2. [Figure 15] FIG. 10 is a schematic diagram showing the configuration of Comparative Example 3. [Figure 16] FIG. 1 is a schematic diagram illustrating the configuration of an inkjet printer as a device that ejects liquid. [Figure 17] FIG. 1 is a perspective view showing an example of the placement of an inkjet printer in a vehicle. [Figure 18] FIG. 1 is a diagram showing an example of an electrode manufacturing apparatus as a liquid ejection apparatus equipped with a liquid ejection head according to the present embodiment. 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 a front view of the liquid ejection head 1, and Fig. 2 is a perspective view of the liquid ejection head 1 as seen from diagonally below. In Figs. 1 and 2, the longitudinal direction of the liquid ejection head 1 (the direction in which the nozzles are arranged) is defined as the X direction, and the lateral direction of the liquid ejection head 1 is defined as the Y direction. The height direction of the liquid ejection head 1 (the direction in which liquid is ejected from the nozzles 111) is defined as the Z direction. These coordinate definitions will be the same in the subsequent figures unless otherwise specified.

[0010] The liquid ejection head 1 includes a housing 10 and a nozzle plate 101 on which a plurality of nozzles 111 are arranged. The housing 10 has an upper housing 10a and a lower housing 10b that serves as a flow path member in which a liquid flow path 112 (see FIG. 5) is formed. The upper housing 10a and the lower housing 10b can also be formed integrally. The upper housing 10a and the lower housing 10b are integrated by diffusion bonding.

[0011] The overall dimensions of the housing 10 can be, for example, 80 mm in length (X-axis direction), 25 mm in width (Y-axis direction), and 15 mm in thickness (Z-axis direction). The material of the housing 10 can be, for example, stainless steel (SUS430).

[0012] A cover 20 is attached to the top of the upper housing 10a. Electrical equipment is disposed inside this cover 20. A connector section 2 for the electrical equipment is provided at the top end of the cover 20.

[0013] A nozzle plate 101 made of a metal such as corrosion-resistant stainless steel (SUS430) is disposed on the underside of the lower housing 10b. A plurality of fine nozzles 111 for ejecting liquid are formed in the nozzle plate 101. The lower housing 10b and the nozzle plate 101 are also integrated by diffusion bonding. The surface roughness of the underside of the lower housing 10b to which the nozzle plate 101 is bonded is set to Ra 0.01 μm or less.

[0014] The nozzles 111 of the nozzle plate 101 are arranged in a staggered pattern in two rows. By arranging the nozzles in a staggered pattern in multiple rows, it is possible to achieve high image quality, a more compact device, and improved productivity by expanding the coating area, without having to position the nozzle plate 101 at an angle to the printing direction.

[0015] One end of the lower housing 10b in the X direction is provided with a supply port 11 that communicates with a flow path 112 (see FIG. 5) provided in the lower housing 10b and supplies liquid. Another end of the lower housing 10b in the X direction is provided with a recovery port 12 that communicates with the flow path 112 (see FIG. 5) and discharges liquid from the flow path.

[0016] As shown in Figure 1, the supply port 11 and the recovery port 12 are connected via a circulation passage L, and pressurized liquid pressurized by a pump P in the circulation passage L is supplied to the supply port 11. The pressurized liquid that is not discharged from the nozzle 111 is recovered from the recovery port 12 and then supplied again to the supply port 11 via the circulation passage L and the pump P.

[0017] In the liquid ejection head 1 of this embodiment, the liquid sending pressure of the supply port 11 is increased to several hundred kPa, so the peripheral edge of the nozzle plate 101 and the housing 10 are firmly joined by direct bonding such as diffusion bonding.

[0018] FIG. 3 is a front view of the liquid ejection head 1 with the lower housing 10b removed, and FIG. 4 is an enlarged perspective view of the lower end of the liquid ejection head with the lower housing 10b removed. As shown in Figures 3 and 4, when the lower housing 10b is removed, the tip of the needle valve 113, which is a shaft-shaped member and valve member, is exposed. The needle valve 113 is supported by a bearing 121 provided on the underside of the upper housing 10a so that it can move in the Z direction. The needle valve 113 is made of a corrosion-resistant metal such as stainless steel, and is very thin, with a diameter of 1 mm or less at its narrowest point and approximately 2 mm at its widest point. This thin needle valve 113 is exposed from the bearing 121 of the upper housing 10a by a length of, for example, 1 to 20 mm.

[0019] A valve element 113a serving as a tip member is attached to the tip of the needle valve 113. An elastic O-ring 113b serving as a sealing member and a washer 113c for fixing the O-ring 113b to the needle valve 113 are disposed above the valve element 113a. The outer peripheral surface of the O-ring 113b contacts the inner peripheral surface of a valve through-hole 132 provided in the lower housing 10b, thereby providing a seal between the flow path 112 and the space in the upper housing 10a that accommodates the piezoelectric element 114.

[0020] FIG. 5 is a cross-sectional view of the liquid ejection head 1 taken along a plane perpendicular to the X direction. 5, a needle valve 113 and a piezoelectric element 114, which is an actuator and driving means for driving the needle valve 113, are disposed in the upper housing 10a along the Z direction. The piezoelectric element 114 is held in a central space 115a of a holding member 115.

[0021] The holding member 115 is disposed in the upper housing 10a so that its position can be adjusted in the vertical direction (Z direction) in Fig. 5. A rear end portion 115c of the holding member 115 is positioned and fixed to the upper housing 10a by a fixing screw 124. A female threaded hole 115d is formed in the rear end portion 115c of the holding member 115 in a direction perpendicular to the Z direction, and the tip of the fixing screw 124 is screwed into this female threaded hole 115d.

[0022] An elongated hole 30 is formed in the Z direction at the top end of the upper housing 10a, and a fixing screw 124 is inserted into this elongated hole 30. When the fixing screw 124 is loosened, the holding member 115 becomes movable up and down.

[0023] 5, the fixing screw 124 is tightened and fixed to the elongated hole 30 at a position where a predetermined gap δ is formed between the valve body 113a and the nozzle 111. In this state, the liquid ejection head 1 is delivered as a product. On the other hand, when the liquid ejection head is to be used, the position of the holding member 115 is adjusted and tightened and fixed so that the valve body 113a abuts against the nozzle plate 101 with a predetermined pressure.

[0024] Springs are formed on both the upper and lower ends of the holding member 115, and the springs hold the piezoelectric element 114 in a compressed state in the Z direction. The rear end of the needle valve 113 is connected to the tip 115b of the holding member 115, with the piezoelectric element 114 and the needle valve 113 concentrically arranged.

[0025] When no voltage is applied to the piezoelectric element 114, the needle valve 113 closes the nozzle 111. Therefore, even if pressurized liquid is supplied to the flow path 112, the liquid is not ejected from the nozzle 111.

[0026] The piezoelectric element 114 is operated in a d31 mode in which it contracts when a voltage is applied by the voltage application means. When the piezoelectric element 114 contracts in the Z direction, the holding member 115 contracts in the Z direction due to the biasing force of the spring portion. This causes the needle valve 113 connected to the tip portion 115b of the holding member 115 to move in a direction away from the nozzle 111 (-Z direction), opening the nozzle 111.

[0027] It is also possible to configure the needle valve 113 to open the nozzle 111 when no voltage is applied to the piezoelectric element 114. In this case, the piezoelectric element 114 operates in d33 mode, in which it expands when voltage is applied, moving the needle valve 113 toward the nozzle 111 and closing the nozzle 111. The d33 mode of the piezoelectric element 114 has high responsiveness and a large displacement. Therefore, the d33 mode is suitable when it is desired to increase the responsiveness of the opening and closing operation of the needle valve 113 and reduce variations in the droplet speed and droplet volume of the liquid ejected from the nozzle 111.

[0028] In the above description, the needle valve 113 is driven by the piezoelectric element 114, but the needle valve may be driven by a solenoid, or may be driven by air pressure or hydraulic pressure.

[0029] 6(a) is a cross-sectional view of the liquid ejection head 1 taken along a line perpendicular to the Y direction, and FIG. 6(b) is a diagram showing the flow of liquid within a flow path 112. As shown in FIG. In this embodiment, as described above, eight nozzles 111 are arranged in a staggered pattern on the nozzle plate 101, forming two rows of nozzles. The nozzles 111 are formed by pressing, etching, or the like. Needle valves 113 are provided corresponding to each of these nozzles 111, and the nozzles 111 are opened and closed by valve bodies 113a at the tips of the needle valves. Note that 2a and 2b in FIG. 6(a) are lead wires of the connector portion 2.

[0030] As shown in Figure 6(b), a flow path 112 through which liquid flows is formed in the lower housing 10b, and one end in the X direction is connected to the supply port 11, and the other end in the X direction is connected to the recovery port 12. As shown by the arrows in Figure 6(b), the liquid in the flow path 112 flows from the supply port 11 to the recovery port 12.

[0031] The materials for the nozzle plate 101 and the housing 10 are not particularly limited and can be selected appropriately depending on the purpose, but a material that is corrosion-resistant to high-pressure liquid and has sufficient strength is preferred. Examples of materials that can be selected for the nozzle plate 101 and the housing 10 include stainless steel, Al, Bi, Cr, InSn, ITO, Nb, Nb2O5, NiCr, Si, SiO2, Sn, Ta2O5, Ti, W, ZAO (ZnO + Al2O3), and Zn. These may be used alone or in combination of two or more. Of these, stainless steel is preferred from the viewpoint of rust resistance.

[0032] Misalignment of the nozzle plate 101 relative to the housing 10 causes a misalignment between the axial center of the needle valve 113, which is held in the housing 10 via the bearing 121, and the center of the nozzle 111. Hereinafter, the misalignment between the axial center of the needle valve 113 and the center of the nozzle 111 will be referred to as concentricity misalignment. Misalignment of the needle valve 113 and the nozzle 111 can affect the sealing performance of the nozzle 111, such as by causing the nozzle to bend.

[0033] Therefore, in this embodiment, in order to suppress misalignment of the concentricity between the needle valve 113 and the nozzle 111, the nozzle plate 101 is accurately positioned in the lower housing 10b and diffusion-bonded to the housing 10. Hereinafter, the positioning structure for the nozzle plate 101 and the lower housing will be described as Examples 1 to 4.

[0034] [Example 1] 7A and 7B are diagrams illustrating the positioning structure between the nozzle plate 101 and the lower housing 10b in Example 1, and Fig. 7A is a cross-sectional view perpendicular to the Y direction of a laminated plate made up of the lower housing 10b and the nozzle plate 101 positioned in the lower housing 10b. Fig. 7B is a bottom view of the nozzle plate 101, and Fig. 7C is a bottom view of the lower housing 10b. Fig. 7D is a view seen from the direction of arrow D in Fig. 7A, and Fig. 8E is a schematic diagram showing the posture when the nozzle plate 101 is diffusion-bonded to the lower housing 10b.

[0035] The nozzle plate 101 in the first embodiment is a rectangular, flat plate, and both ends of the nozzle plate 101 in the arrangement direction of the nozzles 111 (X direction) are positioned in the lower housing 10b. Circular positioning holes 130a and 130b are formed at both ends of the nozzle plate 101 in the X direction. The positioning hole 130a on the left side in the figure is a primary positioning reference and is a circular hole with a diameter of 1.01 mm. Meanwhile, the positioning hole 130b on the right side in the figure is a secondary positioning reference and is a circular hole with a diameter of 1.05 mm, which is larger than the diameter of the primary positioning hole 130a. Here, both ends of the nozzle plate 101 in the nozzle 111 arrangement direction (X direction) refer to regions near both ends of the nozzle plate 101 in the X direction. For example, they may be near nozzles located at the ends of the nozzle 111 arrangement, or may be regions outside the nozzle 111 arrangement in the X direction.

[0036] The nozzle plate 101 of Example 1 is made of stainless steel (SUS430), and the overall dimensions of the nozzle plate 101 are 119 mm long x 21 mm wide x 0.5 mm thick, with a surface roughness of Ra 0.01 μm or less. The nozzle plate 101 shown in Figure 8(b) has eight nozzles 111, each 0.3 mm in diameter, arranged in a staggered pattern in two rows at equal intervals. The nozzles 111 are formed by pressing, etching, or the like.

[0037] Positioning holes 131a, 131b are also formed at both ends in the X direction of the lower housing 10b of Example 1. The positioning holes 131a, 131b are arranged in the same positions as the positioning holes 130a, 130b of the nozzle plate 101. The positioning holes 131a, 131b of the housing are round holes with a diameter of 1.01 mm and an effective depth of 2.3 mm.

[0038] Furthermore, one end of the lower housing in the X direction (the left end in the figure) has a female thread portion 150a, which serves as a through-hole extending in the X direction from a side surface of the lower housing 10b perpendicular to the X direction and communicating with the positioning hole 130a. In Example 1, the center position of the female thread portion 150a is located at the center of the shorter side (Y direction) of the lower housing 10b, and the female thread portion 150a is provided 1.5 mm in the -Z axis direction from the bottom surface of the lower housing. Note that the female thread portion 150a may be provided obliquely rather than perpendicularly to the side surface of the lower housing 10b. In Example 1, the female thread portion 150a is, for example, M1.6 with a pitch of 0.35 mm. The female thread portion 150a is obtained by forming a through-hole by drilling and then forming a thread groove on the inner peripheral surface by tapping. Note that the nominal diameter and position of the female thread portion 150a are not limited to those described above and may be appropriately set depending on the fixing member to be screwed into the female thread portion 150a.

[0039] The lower housing 10b is also provided with a plurality of valve through holes 132 through which the needle valves 113 pass. The diameter of the valve through holes 132 is 2.85 mm, and the valve through holes are formed by drilling.

[0040] The material of the lower housing 10b in Example 1 is the same type of stainless steel (SUS430) as that of the nozzle plate 101. The overall dimensions of the lower housing 10b are length 120 mm x width 22 mm x thickness 8.5 mm. The surface roughness of the joint surface with the nozzle plate 101 is Ra 0.01 μm or less.

[0041] By using the same type of stainless steel material (SUS430) for the lower housing 10b and the nozzle plate 101, it is possible to suppress the occurrence of distortion due to differences in thermal expansion coefficients when heated during diffusion bonding, which will be described later.

[0042] Positioning pins 140 serving as positioning members are inserted into the hole formed by nozzle positioning hole 130a and housing positioning hole 131a, and into the hole formed by nozzle positioning hole 130b and housing positioning hole 131b. In the first embodiment, the material of positioning pin 140 is the same type of stainless steel (SUS430) as that of lower housing 10b and nozzle plate 101. Note that the material of positioning pin 140 is not limited to the above, and may be, for example, a stainless steel other than SUS430.

[0043] The overall dimension of the positioning pin 140 is a length of 2.7 mm. The depth of the hole from the positioning holes 130a, 130b of the nozzle plate and the positioning holes 131a, 131b of the housing is 2.8 mm (thickness of the nozzle plate 101: 0.5 mm + effective depth of the positioning holes 131a, 131b of the housing: 2.3 mm). Therefore, the positioning pin 140 is located 0.1 mm away from the bottom surface of the nozzle plate 101, so that it does not interfere with the pressure plate during diffusion bonding, which will be described later.

[0044] In Example 1, the diameter of the positioning pin 140 is 0.995 mm, which is shorter than the positioning holes 131a and 131b (diameter: 1.01 mm) of the housing and the positioning holes 130a and 130b (diameter: 1.01 mm, diameter 1.05 mm) of the nozzle plate. As a result, the positioning pin 140 is a clearance fit into the positioning holes 131a and 131b of the housing, and a predetermined gap is maintained between the positioning pin 140 and the positioning holes of the housing.

[0045] A fixing member 160a having a male screw is screwed into the female screw portion 150a, and the positioning pin 140, which penetrates the female screw portion 150a and is inserted into the positioning hole 131a of the housing, is pressed toward the nozzle side (inward) in the X direction. By pressing the fixing member 160a, the positioning pin 140 is pressed against the inner peripheral surface of the positioning hole 131a on the nozzle side, and is fixed within the positioning hole 131a.

[0046] In the first embodiment, the fixing member 160a is a set screw made of stainless steel (SUS430) and has a diameter of M1.6, a pitch of 0.35 mm, and a length of 3 mm. The tip shape of the fixing member 160a that contacts the positioning pin 140 can be, for example, a concave tip, a flat tip, a pointed tip, a rod tip, or a hemispherical ball screw. The material and size of the fixing member 160a are not limited to those described above, and the material can be stainless steel other than SUS430, for example, and the set screw size can be selected to correspond to the nominal diameter of the female thread portion 150a.

[0047] Next, the diffusion bonding between the nozzle plate 101 and the lower housing 10b will be described. FIG. 8 is a process flow diagram of the diffusion bonding, and FIG. 9 is a schematic diagram of a diffusion bonding apparatus 200. As shown in FIG. Diffusion bonding is a method of bonding the nozzle plate 101 and the lower housing 10b under heat and pressure conditions without using an adhesive, using only atomic migration between the materials of the nozzle plate 101 and the lower housing 10b. When the nozzle plate 101 is bonded to the lower housing 10b with an adhesive, there is a risk that the nozzle plate 101 will be attached at an angle relative to the lower housing 10b due to variations in the thickness of the adhesive. This could affect the nozzle sealing performance of the needle valve 113 and the performance of discharging liquid from the nozzle 111. On the other hand, diffusion bonding can bond the nozzle plate 101 to the lower housing 10b without using an adhesive, and can prevent the nozzle plate 101 from being attached at an angle relative to the lower housing 10b.

[0048] As shown in FIG. 8, the diffusion bonding mainly comprises three steps: a surface treatment step, a stacked plate setting step in which a stacked plate made up of the lower housing 10b and the nozzle plate 101 is set, and a bonding step.

[0049] The surface treatment step is a step of degreasing the surfaces of the nozzle plate 101, the lower housing 10b, the positioning pins 140, and the fixing member 160a with acetone.

[0050] The stacked plate setting step includes an assembling step of assembling the nozzle plate 101 to the lower housing 10b, and a step of setting the stacked plate consisting of the assembled lower housing 10b and nozzle plate 101 in the diffusion bonding apparatus 200.

[0051] In the assembly process, first, the bottom surface of the lower housing 10b (the surface to which the nozzle plate 101 is joined) is placed facing up, and the positioning pins 140 are inserted into the positioning holes 131a, 131b of the lower housing 10b. As described above, in the first embodiment, the diameter of the positioning pin 140 is shorter than the diameter (inner diameter) of the positioning holes 131a, 131b of the housing. Therefore, the positioning pins 140 can be easily inserted into the positioning holes 131a, 131b of the housing.

[0052] Next, the positioning pins 140 inserted into the positioning holes 131a and 131b of the housing are inserted into the positioning holes 130a and 130b of the nozzle plate 101 to position the nozzle plate 101 in the lower housing 10b. As described above, the diameter of the positioning pins 140 is shorter than the diameter (inner diameter) of the positioning holes 130a and 130b of the nozzle plate, so the positioning pins 140 can be easily inserted into the positioning holes 130a and 130b of the nozzle plate 101.

[0053] Next, fixing member 160a is screwed into female thread portion 150a, and fixing member 160a is used to push positioning pin 140 inserted into main reference positioning hole 130a. As a result, positioning pin 140 abuts at least the inner circumferential surface of positioning hole 131b of the housing, and positioning pin 140 is clamped and fixed between fixing member 160a and the positioning hole of the housing in an attitude parallel to the Z direction, which is the insertion direction of the positioning pin.

[0054] In the first embodiment, the diameter of the positioning hole 131a in the housing is 1.001 mm, and the diameter of the positioning pin 140 is 0.995 mm. Therefore, the center of the positioning pin 140 fixed to the fixing member 160a is fixed with a deviation of 7.5 μm toward the center of the housing in the X direction relative to the center of the positioning hole 131a in the housing. Therefore, by abutting the center side (+X direction side) of the positioning hole 130a of the nozzle plate against the positioning pin 140 for positioning, the center of the positioning hole 131a in the housing and the center of the positioning hole in the nozzle plate can be aligned, and the nozzle plate can be attached to the housing without any positional deviation.

[0055] Furthermore, even if the nozzle plate is displaced in the +X direction relative to the housing, the amount of positional displacement is 15 μm, and the nozzle plate 101 is positioned relative to the lower housing 10b within a range of 0 to 15 μm in the X direction.

[0056] Meanwhile, the center position of the positioning hole 131b of the housing in the Y direction and the center position of the positioning pin 140 fixed to the fixing member 160a are approximately the same. Therefore, when the nozzle plate 101 is not misaligned with respect to the lower housing 10b, the gap in the Y direction between the positioning pin 140 fixed to the fixing member 160a and the main reference positioning hole 130a of the nozzle plate 101 is 7.5 μm. Therefore, the nozzle plate 101 is positioned with respect to the lower housing 10b within a range of 0 to 7.5 μm in the Y direction.

[0057] After the nozzle plate 101 is positioned in the lower housing 10b and the assembly process is completed, the laminated plate consisting of the lower housing 10b and the nozzle plate 101 is set in a predetermined position on the lower pressure plate 201a of the diffusion bonding apparatus 200. A vacuum hot press machine (FVHP-R-750 FRET-300) can be used as the diffusion bonding apparatus 200.

[0058] 9, the diffusion bonding apparatus 200 has a lower pressure plate 201a on which the stacked plates are set, and an upper pressure plate 201b fixed to an upper ram 202. The upper ram 202 is configured to be slidable in the vertical direction. The upper pressure plate 201b and the lower pressure plate 201a are made of ceramic members.

[0059] After the stacked plate consisting of the lower housing 10b and the nozzle plate 101 is set on the lower pressure plate 201a, the upper ram 202 is lowered. Then, as shown in Fig. 9, the stacked plate consisting of the lower housing 10b and the nozzle plate 101 is sandwiched and pressed between the upper pressure plate 201b and the lower pressure plate 201a.

[0060] In the first embodiment, as described above, the overall dimension of the positioning pin 140 is 2.7 mm in length. Meanwhile, the depth of the hole consisting of the positioning holes 130a and 130b in the nozzle plate and the positioning holes 131a and 131b in the housing is 2.8 mm (thickness of the nozzle plate 101: 0.5 mm + effective depth of the positioning holes 131a and 131b in the housing: 2.3 mm). As such, the positioning pin 140 is set back 0.1 mm from the nozzle surface of the nozzle plate 101. Therefore, the positioning pin 140 does not interfere with the upper pressure plate 201b, and the upper pressure plate 201b can pressurize the entire surface of the nozzle plate 101. The length of the positioning pin 140 does not need to protrude outward from the positioning holes 130a and 130b, and can be extended up to 2.8 mm. In this case, the tip of the positioning pin 140 is flush with the outer edge of the positioning holes 130a and 130b, but does not interfere with the upper pressure plate 201b during diffusion bonding.

[0061] In the bonding process using the diffusion bonding apparatus 200, a load of 53 kN or more is applied by a pair of pressure plates 201a and 201b, and a pressure of 20 MPa or more is applied to the stacked plate consisting of the lower housing 10b and the nozzle plate 101. With a pressure of 20 MPa or more applied to the stacked plate, a vacuum of 1.0×10 -4 After raising the temperature to 800°C to 1000°C under 1000 Pa, the temperature is maintained for 10 minutes to 1 hour. This allows the nozzle plate 101 to be diffusion bonded to the lower housing 10b. After the diffusion bonding, the nozzle plate 101 is cooled in a furnace or with Ar gas.

[0062] The positioning pins 140 may be removed after joining the nozzle plate 101 to the lower housing 10b, or may be left as they are. If they are left as they are, the positioning pins 140 inserted into the secondary positioning holes 130b of the nozzle plate 101 are not fixed, so they are fixed by pouring adhesive into the positioning holes 131b of the housing, for example.

[0063] The nozzle plate 101 and the lower housing 10b are made of the same type of stainless steel (SUS430), and the linear expansion coefficients of the nozzle plate 101 and the lower housing 10b are the same. However, because the thermal capacities of the nozzle plate 101 and the lower housing 10b are different, the temperature rise speed of the nozzle plate 101 and the temperature rise speed of the lower housing 10b differ from each other. Therefore, when the temperature rises during diffusion bonding, the speed of thermal expansion of the thinner nozzle plate 101 is faster than the speed of thermal expansion of the lower housing 10b. As a result, when the temperature rises to 800°C to 1000°C during diffusion bonding, the positioning pin 140 is pressed into the positioning hole of the nozzle plate 101 due to thermal expansion.

[0064] If the positioning pin 140 is not fixed to the positioning hole 131a of the housing and is configured to move freely within a predetermined range, as shown in Figure 10, when the positioning pin 140 is pushed in due to thermal expansion of the nozzle plate 101, the positioning pin 140 will tilt within the positioning hole 131a. This tilting will deteriorate the positioning accuracy of the nozzle plate 101 relative to the lower housing 10b. In particular, the positioning hole 130a, which serves as the main reference and has a small diameter and a narrow gap between it and the positioning pin, may come into contact with the positioning pin when the temperature rises during diffusion bonding, causing the positioning pin 140 to tilt.

[0065] For example, as in the embodiment, if the diameter of the positioning pin 140 is 0.995 mm and the diameter of each of the positioning holes 130a, 131a is 1.001 mm, tilting the positioning pin 140 will cause the nozzle plate 101 to be misaligned with respect to the lower housing 10b by 15 μm or more. This may result in the nozzle plate 101 being diffusion-bonded to the lower housing 10b in a misaligned state. As a result, the concentricity between the needle valve 113 and the nozzle 111 may fall outside the specified range, potentially preventing the desired sealing and ejection performance.

[0066] Furthermore, as shown in Figure 10, when the positioning pin 140 tilts, the positioning pin 140 comes into point contact with the edge of the positioning hole 130a in the nozzle plate 101 and the edge of the positioning hole 131a in the housing. During diffusion bonding, the positioning pin 140 is exposed to high temperatures, making it prone to deformation. Therefore, when the positioning pin 140 is further pressed by thermal expansion of the nozzle plate 101 from the state shown in Figure 10, stress may concentrate at the point contact portion, causing the positioning pin 140 to deform. As a result, there is a risk that the positioning pin 140 may become even more misaligned with respect to the lower housing 10b.

[0067] In contrast to this, in Example 1, the positioning pin 140 inserted into the main reference positioning hole 130a of the nozzle plate has its outer peripheral surface sandwiched between the inner peripheral surface of the positioning hole 131a of the housing and the fixing member 160a, and is fixed in an attitude parallel to the Z direction. As a result, even if the positioning pin 140 is pushed by the thermal expansion of the nozzle plate 101 when the temperature rises during diffusion bonding, the positioning pin 140 does not tilt, and can maintain an attitude parallel to the Z direction.

[0068] Furthermore, by fixing the positioning pin 140, the load acting on the positioning pin 140 due to thermal expansion of the nozzle plate 101 increases. However, because the positioning pin 140 does not tilt, the positioning pin 140 makes line contact or contacts over a certain area with the inner circumferential surface of the positioning hole 130a, which serves as the main reference in the nozzle plate. This prevents localized stress concentrations from occurring on the positioning pin 140. Therefore, even if the load acting on the positioning pin 140 due to thermal expansion of the nozzle plate 101 increases, deformation of the positioning pin 140 can be effectively suppressed. This prevents the positional deviation of the nozzle plate 101 relative to the lower housing 10b from worsening during diffusion bonding. This prevents the concentricity deviation between the needle valve 113 and the nozzle 111 from falling outside the specified range.

[0069] Note that the positioning pin 140 can also be fixed to the lower housing 10b in a position parallel to the Z direction by press-fitting the positioning pin 140 into the positioning hole 131a of the housing. However, fixing the positioning pin 140 into the positioning hole 131a of the housing by press-fitting has the following drawbacks. Specifically, when the positioning pin 140 is fixed into the positioning hole 131a of the housing by press-fitting, residual stress is generated in the positioning pin 140. As a result, the positioning pin 140 may be deformed due to the release of residual stress in the positioning pin 140 caused by heating during diffusion bonding. Furthermore, when the positioning pin 140 is fixed by press-fitting, the thermal expansion of the positioning pin 140 caused by heating during diffusion bonding and the deformation of the positioning pin 140 caused by the release of residual stress in the positioning pin 140 cannot be released within the positioning hole 131a. As a result, the positioning hole 131a of the housing itself may be deformed. If the positioning pins are fixed by press-fitting in this way, there is a risk that the positioning pins and the positioning holes 131a, 131b may be deformed, which may deteriorate the positioning accuracy and worsen the misalignment of the nozzle and the needle valve.

[0070] In contrast, in Example 1, a predetermined gap is formed between the positioning hole 131a of the housing and the positioning pin 140, and the positioning pin 140 is fixed to the positioning hole 131a of the housing by a fixing member 160a that is screwed into the female thread portion 150a. As such, since the positioning pin 140 is not fixed by press-fitting, almost no residual stress occurs in the positioning pin 140. As a result, the residual stress in the positioning pin 140 is released by heating during diffusion bonding, and deformation of the positioning pin 140 is effectively suppressed.

[0071] Furthermore, because there is a gap at least in the Y direction between the positioning hole 131a and the positioning pin 140, thermal expansion of the positioning pin 140 due to heating during diffusion bonding can be allowed to escape. This makes it possible to suppress deformation of the positioning hole 131a and the positioning pin, compared to press-fitting, which leaves no escape route for thermal expansion of the positioning pin 140 inside the positioning hole of the housing. This prevents deterioration of positioning accuracy and keeps the concentricity deviation between the nozzle and the needle valve within a specified range.

[0072] On the other hand, the secondary reference positioning hole 130b of the nozzle plate has a larger diameter than the primary reference positioning hole 130a, so that when the temperature rises during diffusion bonding, thermal expansion of the nozzle plate 101 prevents the secondary reference positioning hole 130b from coming into contact with the positioning pin 140.

[0073] Furthermore, the positioning pin 140 inserted into the secondary-reference positioning hole 130b of the nozzle plate 101 is not fixed to the positioning hole of the housing. Therefore, if the positioning pin 140 inserted into the secondary-reference positioning hole 130b of the nozzle plate 101 comes into contact with the positioning pin 140 due to thermal expansion of the nozzle plate during temperature rise during diffusion bonding, the positioning pin can be tilted in the X direction to release the thermal expansion of the nozzle plate. This makes it possible to suppress deformation of the nozzle plate 101, such as distortion, warping, or waviness. Note that even if the positioning pin 140 inserted into the secondary-reference positioning hole 130b of the nozzle plate 101 is tilted in the X direction, the positioning accuracy will not deteriorate because the position in the X direction is accurately determined by the positioning pin 140 inserted into the primary-reference positioning hole 130a.

[0074] When the temperature rises to 800°C to 1000°C during diffusion bonding, the nozzle plate 101 undergoes rapid thermal expansion, which worsens the misalignment of the nozzle 111 and the needle valve 113. However, the nozzle plate 101 and the lower housing 10b are made of the same material (SUS430) and have the same linear expansion coefficient. Therefore, after the nozzle plate 101 and the lower housing 10b are heated to the same temperature, the misalignment of the nozzle 111 and the needle valve 113 is eliminated, and the nozzle 111 and the needle valve 113 are diffusion bonded with the misalignment of the concentricity within a specified range.

[0075] The positioning pin 140 and the fixing member 160a are also made of the same material (SUS430) as the lower housing 10b, and have the same linear expansion coefficient as the lower housing 10b. This prevents stress from occurring between the fixing member and the lower housing, between the positioning pin and the fixing member, and between the positioning pin and the lower housing due to differences in thermal expansion after the temperature rises during diffusion bonding. This prevents deformation of the positioning pin, the fixing member, and the lower housing during diffusion bonding. As a result, misalignment of the nozzle 111 and the needle valve 113 can be prevented.

[0076] [Example 2] FIG. 11 is a bottom view of the nozzle plate 101 in the second embodiment. 11, the secondary reference positioning hole 130b of the nozzle plate is an elongated hole that is long in the X direction, and is otherwise the same as Example 1. The secondary reference positioning hole 130b of the nozzle plate has a length (length in the X direction) of 1.05 mm and a width (length in the Y direction) of 1.01 mm.

[0077] The positioning holes 130a of the nozzle plate as the main reference are the same as those in the first embodiment, and therefore, similarly to the first embodiment, the nozzle plate 101 is positioned with respect to the lower housing 10b with an accuracy of 0 to 15 μm.

[0078] On the other hand, on the secondary reference side, the positioning hole 130b of the secondary reference can narrow the gap with the positioning pin in the Y direction compared to a round hole with a diameter of 1.05 mm. This allows for higher positioning accuracy around the Z direction of the nozzle plate 101 relative to the lower housing 10b compared to Example 1.

[0079] The gap between the positioning hole 130b of the secondary reference and the positioning pin 140 in the X direction in the second embodiment is the same as in the first embodiment, and similarly to the first embodiment, it is possible to prevent the positioning hole 130b of the secondary reference from coming into contact with the positioning pin 140 due to thermal expansion in the X direction of the nozzle plate when the temperature rises during diffusion bonding. This makes it possible to prevent the positioning pin 140 inserted into the positioning hole 130b of the secondary reference from tilting, similarly to the first embodiment.

[0080] Furthermore, the length in the X direction of the positioning hole 130b of the secondary reference in Example 2 is the same as that of the positioning hole of the secondary reference in Example 1. Therefore, in Example 2 as well, as in Example 1, when the temperature rises during diffusion bonding, thermal expansion of the nozzle plate 101 in the X direction makes it difficult for the positioning hole 130b of the secondary reference to come into contact with the positioning pin 140. As a result, the thermal expansion of the nozzle plate in the X direction is not hindered by the positioning pin 140 inserted into the positioning hole 130b of the secondary reference, and distortion or deformation of the nozzle plate 101 can be suppressed.

[0081] Furthermore, the positioning pin 140 inserted into the positioning hole 130b of the secondary reference is not fixed. Therefore, even if the positioning hole 130b of the secondary reference abuts against the positioning pin 140, the positioning pin can move or tilt in the X direction, allowing for thermal expansion of the nozzle plate in the X direction. This effectively prevents distortion or deformation of the nozzle plate 101. Furthermore, because the positioning pin inserted into the positioning hole 130b of the secondary reference positions the nozzle plate around the Z direction, tilting the positioning pin in the X direction does not affect the positioning accuracy.

[0082] [Example 3] 12A and 12B are schematic diagrams showing the configuration of Example 3, in which FIG. 12A is a bottom view of the lower housing 10b, and FIG. 12B is a cross-sectional view of a stacked plate consisting of the lower housing 10b and a nozzle plate 101. In this third embodiment, a positioning pin 140 to be inserted into a positioning hole 130a of the main reference is clamped and fixed in two directions, that is, the X direction and the Y direction. Specifically, the following configuration is added to the configuration of Example 1. That is, a second female screw portion 150b serving as a second communicating hole that extends in the Y direction from a side surface of the lower housing 10b perpendicular to the Y direction and communicates with the positioning hole 131a, and a second fixing member 160b that is screwed into this second female screw portion 150b are provided.

[0083] The second female screw portion 150b, like the female screw portion 150a extending in the X direction, has a dimension of M1.6 and a pitch of 0.35 mm, and is obtained by forming a communicating hole by drilling and then forming a screw groove on the inner surface by tapping. The position of the second female screw portion 150b is 3 mm in the +X-axis direction from the end of the positioning hole 131a on the side surface of the lower housing perpendicular to the Y-direction, and 1.5 mm in the +Z-axis direction from the bottom surface of the housing.

[0084] Like the fixing member 160a, the second fixing member 160b is a set screw made of SUS430, measuring M1.6 x 0.35 mm and 3 mm long. The material and size of the second fixing member 160b are not limited to those mentioned above, and the material may be stainless steel other than SUS430, and the set screw size may be selected to correspond to the nominal diameter of the second female thread portion 150b. The tip of the second fixing member 160b may have a shape similar to that of the fixing member 160a, such as a pointed tip or a rod tip.

[0085] The second fixing member 160b is screwed into the second female thread portion 150b, and the positioning pin 140 inserted into the positioning hole 131a of the housing is pushed in the Y direction with its tip protruding from the second female thread portion 150b. By pushing the second fixing member 160b in this way, the positioning pin 140 is pressed against the inner circumferential surface of the positioning hole 131a on the side opposite to the second female thread portion. As a result, the positioning pin 140 is clamped and fixed in the Y direction between the second fixing member 160b and the inner circumferential surface of the positioning hole 131a.

[0086] Furthermore, the positioning pin 140 in the positioning hole 131a is pushed in the X direction by the fixing member 160a, as in Example 1. As a result, the positioning pin 140 is clamped and fixed in the X direction also between the fixing member 160a and the inner circumferential surface of the positioning hole 131a on the inside in the X direction.

[0087] In this way, in Example 3, the positioning pin is clamped and fixed in the X and Y directions, so that it is firmly fixed in the positioning hole 131a of the housing in an orientation parallel to the Z direction. This makes it possible to suppress tilting of the positioning pin due to thermal expansion of the nozzle plate when the temperature rises during diffusion bonding, compared to Example 1, and to maintain an orientation parallel to the Z direction.

[0088] On the other hand, Example 1 has more escape routes for the positioning pins when they thermally expand than Example 3, and therefore has the advantage of being able to suppress deformation of the positioning holes 131a and the positioning pins more than Example 3. Also, compared to Example 3, there is the advantage that the number of parts is smaller, which allows for cost reduction of the device.

[0089] [Example 4] Fig. 13 is a schematic diagram showing the configuration of Example 4, in which Fig. 13(a) is a bottom view of a stacked plate made up of a lower housing 10b and a nozzle plate 101, Fig. 13(b) is a cross-sectional view of the lower housing taken perpendicular to the Z direction, and Fig. 13(c) is a cross-sectional view of the stacked plate made up of a lower housing 10b and a nozzle plate 101 taken perpendicular to the Y direction.

[0090] In Example 4, the nozzle plate 101 is positioned on the lower housing at three locations: both ends in the X direction and the center. Positioning holes 130a and 130b at both ends of the nozzle plate in the X direction are secondary positioning references and are elongated holes with a length (X direction length) of 1.05 mm and a width (Y direction length) of 1.01 mm. Meanwhile, positioning hole 130c at the center in the X direction is the primary positioning reference and is a circular hole with a diameter of 1.01 mm. Here, the central portion in the X direction may be approximately near the center of the nozzle plate 101 in the X direction, for example, the region between the positioning holes at both ends in the X direction. Alternatively, the central portion may be the range in which the nozzles 111 are arranged in the X direction.

[0091] The positioning holes 130a, 130b at both ends in the X direction are formed in the center of the nozzle plate 101 in the Y direction, and the positioning holes 130a, 130b at the center in the X direction are formed at one end in the Y direction (the end on the +Y direction side).

[0092] 13(b), positioning holes 131a, 131b, and 131c are provided in the lower housing 10b at positions corresponding to the positioning holes 130a, 130b, and 130c of the nozzle plate 101. The positioning holes 131a and 131b at both ends of the housing in the X direction are round holes with a diameter of 1.05 mm, and the positioning hole 131c at the center of the housing in the X direction is a round hole with a diameter of 1.01 mm. The positioning pins inserted into each positioning hole have a diameter of 0.995 mm and are made of stainless steel (SUS430), as in Example 1.

[0093] Of the two side surfaces of the lower housing 10b perpendicular to the Y direction, a female screw portion 150a serving as a communicating hole is provided in the center in the X direction of the side surface facing the positioning hole 131c in the center in the X direction. This female screw portion 150a extends in the Y direction and communicates with the central positioning hole 130c. As in the first embodiment, the female screw portion 150a has a size of M1.6 × 0.35 mm and a length of 2.5 mm. After forming a communicating hole by drilling, the female screw portion 150a is formed by tapping the inner peripheral surface to form a thread groove. The center of the female screw portion 150a is located at the center of the lower housing 10b in the X direction, at a position 1.5 mm away from the bottom surface of the lower housing 10b in the −Z direction.

[0094] The fixing member 160a that is screwed into this female screw portion 150a is a set screw made of stainless steel (SUS430) with M1.6 and a pitch of 0.35 mm, as in the first embodiment. Fixing member 160a is screwed into female thread portion 150a, and the positioning pin 140 inserted into positioning hole 131c of the housing is pushed in the Y direction with its tip protruding from female thread portion 150a. By pushing fixing member 160a in this way, positioning pin 140 is pressed against the inner circumferential surface of positioning hole 131c, and positioning pin 140 is clamped and fixed in the Y direction between fixing member 160a and the inner circumferential surface of positioning hole 131c.

[0095] The diameter of the positioning hole 130c of the nozzle plate as the main reference and the diameter of the positioning pin 140 are the same as in the first embodiment, so in this fourth embodiment too, the nozzle plate can be positioned in the lower housing with the same positioning accuracy as in the first embodiment.

[0096] The positioning pin inserted into the primary reference positioning hole 130c is clamped and fixed between the fixed member and the inner peripheral surface of the positioning hole in the housing in a position parallel to the Z direction. Therefore, in Example 4 as well, tilting of the positioning pin 140 due to thermal expansion of the nozzle plate when the temperature rises during diffusion bonding can be prevented, and deterioration of positioning accuracy can be suppressed. This allows the concentricity deviation between the nozzle and the needle valve to be kept within a specified range.

[0097] Furthermore, in this fourth embodiment, the positioning holes 130a, 130b at both ends of the nozzle plate in the X direction serve as secondary references for positioning and are elongated holes that are long in the X direction. Thermal expansion of the nozzle plate in the X direction during temperature rise during diffusion bonding increases toward the ends in the X direction. Therefore, by using the positioning holes 130a, 130b at both ends of the nozzle plate in the X direction as secondary references for positioning and as elongated holes that are long in the X direction, thermal expansion of the nozzle plate in the X direction during temperature rise during diffusion bonding can be more effectively tolerated compared to when one end in the X direction is used as the primary reference for positioning. This effectively suppresses distortion of the nozzle plate 101.

[0098] Furthermore, by providing the main reference positioning hole in the nozzle plate in the central X-direction, where the thermal expansion of the nozzle plate in the X-direction is less than that at the X-direction ends during the temperature rise during diffusion bonding, the load in the X-direction applied to the positioning pin inserted in the main reference positioning hole due to the thermal expansion of the nozzle plate is reduced. This effectively prevents the positioning pin from tilting due to the thermal expansion of the nozzle plate during the temperature rise during diffusion bonding, and prevents a deterioration in positioning accuracy. This effectively keeps the concentricity deviation between the nozzle and the needle valve within a specified range.

[0099] The concentricity between the nozzle and the needle valve was evaluated for the above-mentioned Examples 1 to 4 and the below-mentioned Comparative Examples 1 to 3.

[0100] [Comparative Example 1] In Comparative Example 1, in Example 1, the fixing member 160a is removed and the positioning pin 140 is not fixed in the positioning hole of the housing.

[0101] Comparative Example 2 In Comparative Example 2, as shown in FIG. 14 , the positioning pin 140 inserted into the secondary positioning hole 131b of the nozzle plate 101 is also fixed by a fixing member 160c. Specifically, a female screw portion 150c extending in the X direction and communicating with the positioning hole 131b is provided on a side surface of the housing perpendicular to the X direction on the side of the positioning hole 131b. Then, a fixing member 160c is screwed into this female screw portion 150c, and the positioning pin 140 inserted into the positioning hole 131b is pushed inward in the X direction to be sandwiched and fixed between the fixing member 160c and the inner circumferential surface of the positioning hole 131c. The shapes and materials of the female screw portion 150c and the fixing member 160c are the same as those of the female screw portion 150a on the positioning hole 131a side and the fixing member 160a screwed into the female screw portion 150a.

[0102] Comparative Example 3 In Comparative Example 3, as shown in FIG. 15, the positioning pin is press-fitted into the positioning hole of the housing.

[0103] The concentricity deviation between the nozzle 111 and the needle valve 113 was evaluated by measuring the amount of misalignment between the lower housing 10b and the nozzle plate 101. The concentricity deviation between the needle valve 113 and the nozzle 111 is the sum of the joining accuracy (amount of misalignment) between the nozzle plate 101 and the lower housing 10b, the joining accuracy between the lower housing 10b and the upper housing 10a, and the assembly accuracy of the needle valve 113 to the upper housing 10a (accuracy of the bearing 121). If the joining accuracy between the lower housing 10b and the upper housing 10a and the assembly accuracy of the needle valve 113 to the upper housing 10a are within specified accuracy, the allowable range of the misalignment between the lower housing 10b and the nozzle plate 101 is determined. In this embodiment, if the amount of misalignment between the lower housing 10b and the nozzle plate 101 is 15 μm or less, the concentricity deviation was evaluated as "good." On the other hand, when the amount of misalignment between the lower housing 10b and the nozzle plate 101 was more than 15 μm and not more than 25 μm, the concentricity misalignment was evaluated as "passable." On the other hand, when the amount of misalignment between the lower housing 10b and the nozzle plate was more than 25 μm, the concentricity misalignment evaluation was evaluated as "fail."

[0104] The amount of misalignment between the nozzle plate 101 and the lower housing 10b was measured using a CNC image measuring device (QV-H302T1S-D) according to the following measurement procedure. (1) The assembly consisting of the nozzle plate 101 and the lower housing is set in a CNC image measuring device with the nozzle plate 101 facing upward. (2) Next, the center points of all the valve through-holes 132 and nozzles on the bottom surface of the lower housing are obtained using a CNC image measuring device. (3) Next, for all the valve through-holes 132, the amount of deviation between the center point of the valve through-hole 132 and the center point of the nozzle 111 at the same location is calculated. (4) The maximum amount of deviation from all the calculated amounts of deviation of the center points is determined as the amount of deviation between the nozzle plate 101 and the lower housing 10b.

[0105] Table 1 below shows the evaluation results of the misalignment of the concentricity between the nozzle 111 and the needle valve 113 in Examples 1 to 4 and Comparative Examples 1 to 3.

[0106] [Table 1]

[0107] As shown in Table 1, in Comparative Example 1, the amount of misalignment between the lower housing 10b and the nozzle plate 101 exceeded 25 μm, and the concentricity misalignment evaluation was "fail." In Comparative Example 1, when the positioning pin 140 inserted into the main reference positioning hole 130a of the nozzle plate 101 was checked after diffusion bonding, it was found that the positioning pin 140 was tilted. Deformation of the positioning pin 140 was also confirmed.

[0108] This is because, in Comparative Example 1, the positioning pin 140 inserted into the nozzle plate's main reference positioning hole 130a was not fixed. As a result, due to thermal expansion of the nozzle plate during temperature rise during diffusion bonding, the positioning pin 140 inserted into the nozzle plate's main reference positioning hole 130a was pushed into the nozzle plate 101 and tilted. Furthermore, as the positioning pin 140 tilted, the positioning pin 140 came into point contact with the edge of the positioning hole 130a in the nozzle plate 101 and the edge of the positioning hole 131a in the housing. As a result, a stress concentration area was generated in the positioning pin 140. This is thought to have caused the positioning pin 140 to deform due to the stress concentration area generated in the positioning pin 140, which was in a state where it was prone to deformation due to heating during diffusion bonding. As a result, the positioning pin 140 tilted and deformed, the misalignment between the lower housing 10b and the nozzle plate exceeded 25 μm, resulting in a "fail" concentricity misalignment evaluation.

[0109] In Comparative Example 2, the amount of misalignment between the lower housing 10b and the nozzle plate exceeded 25 μm, and the concentricity misalignment evaluation was “fail.” When the nozzle plate was inspected after diffusion bonding, wavy deformation in the X direction was confirmed.

[0110] This is because, in Comparative Example 2, the positioning pin 140 inserted into the positioning hole 130a of the secondary reference of the nozzle plate is also fixed to the fixing member. Furthermore, the positioning pin 140 inserted into the positioning hole 130a of the secondary reference of the nozzle plate is fixed toward the inside in the X direction. As a result, when the temperature of the nozzle plate rises during diffusion bonding, the inner end of the positioning hole of the secondary reference of the nozzle plate in the X direction abuts against the positioning pin, and the thermal expansion of the nozzle plate in the X direction is restricted by the positioning pins at both ends. This presumably resulted in no escape route for the thermal expansion of the nozzle plate in the X direction, and the nozzle plate, which is prone to deformation due to the heating during diffusion bonding, deformed in a wavy manner. As a result, the amount of misalignment between the lower housing 10b and the nozzle plate exceeded 25 μm, resulting in a "fail" concentricity misalignment evaluation.

[0111] In Comparative Example 3, the misalignment between the lower housing 10b and the nozzle plate exceeded 25 μm, and the concentricity misalignment evaluation was "fail." When the positioning pin inserted into the secondary positioning hole 130a of the nozzle plate after diffusion bonding was inspected, deformation was found in the positioning pin. Deformation was also found in the positioning hole 131a corresponding to the primary positioning hole 130a of the housing.

[0112] This is because, in Comparative Example 3, the positioning pins were fixed by press-fitting into the positioning holes of the housing, which generated residual stress in the positioning pins pressed into the housing. As a result, it is believed that the positioning pins deformed when the residual stress in the positioning pins was released by heating during diffusion bonding. Furthermore, because there was no gap between the positioning holes in the housing, there was no escape route for the positioning pins' thermal expansion due to heating during diffusion bonding. As a result, it is believed that the positioning holes, which were prone to deformation due to heating during diffusion bonding, were deformed by the pressure of the thermal expansion of the positioning pins. As a result, it is believed that the deformation of the positioning pins and the positioning holes in the housing caused the misalignment between the lower housing 10b and the nozzle plate to exceed 25 μm, resulting in a "fail" concentricity evaluation.

[0113] In contrast, in all of Examples 1 to 4, the amount of positional misalignment between the lower housing 10b and the nozzle plate was 25 μm or less, and good results were obtained in the concentricity misalignment evaluation. In Examples 1 to 4, the positioning pin 140 inserted into the main reference positioning hole 130a in the nozzle plate was fixed in an orientation parallel to the Z direction by a fixing member. Therefore, unlike Comparative Example 1, tilting of the positioning pin 140 inserted into the main reference positioning hole 130a in the nozzle plate was suppressed, and deterioration of positioning accuracy was suppressed.

[0114] Furthermore, in all of Examples 1 to 4, unlike Comparative Example 3, there is a clearance between the positioning pin and the positioning hole in the housing to allow for thermal expansion of the positioning pin, and no residual stress occurs in the positioning pin, which effectively prevents deformation of the positioning pin and the positioning hole in the housing.

[0115] Furthermore, in all of Examples 1 to 4, unlike Comparative Example 2, the positioning pins 140 inserted into the secondary positioning holes 130b of the nozzle plate are not fixed. Therefore, the thermal expansion of the nozzle plate in the X direction is not restricted by the positioning on both sides in the X direction. As a result, no wavy deformation occurs in the nozzle plate.

[0116] Therefore, it is believed that in all of Examples 1 to 4, the amount of misalignment between the lower housing 10b and the nozzle plate was 25 μm or less, and good results were obtained in the evaluation of concentricity misalignment.

[0117] In particular, in Example 3, in which the positioning pin 140 inserted into the main reference positioning hole of the nozzle plate was clamped and fixed in two directions, the X direction and the Y direction, the positioning pin could be firmly fixed in an attitude parallel to the Z direction, and tilt of the positioning pin 140 inserted into the main reference positioning hole was effectively suppressed. As a result, the amount of positional misalignment between the lower housing 10b and the nozzle plate was suppressed to 15 μm or less, and the concentricity misalignment evaluation was judged to be "good."

[0118] In addition, Example 4 also received a "good" evaluation for the concentricity deviation. In Example 4, the positioning holes 130a and 130b at both ends of the nozzle plate in the X direction are elongated holes in the X direction and serve as secondary references for positioning, while the positioning hole 130c at the center of the nozzle plate in the X direction is used as the primary reference for the positioning holes. The positioning pin inserted into the positioning hole 130c at the center of the nozzle plate in the X direction is fixed in a position parallel to the Z direction with a fixing member. By using the positioning holes 130a and 130b at both ends of the nozzle plate in the X direction as elongated holes in the X direction and as secondary references for positioning, it is believed that thermal expansion of the nozzle plate in the X direction during temperature rise during diffusion bonding was well tolerated. As a result, distortion of the nozzle plate 101 was well suppressed, and the amount of misalignment with the nozzle plate was kept to 15 μm or less. This is believed to be why the concentricity deviation was evaluated as "good."

[0119] The liquid ejection head 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 described above 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.

[0120] Next, an example of a liquid ejection device having the above-described liquid ejection head 1 will be described.

[0121] FIG. 16 is a schematic diagram of an inkjet printer as a device for ejecting liquid. The inkjet printer 1001 includes a liquid ejection unit 1002 equipped with a liquid ejection head, and a camera 1004 serving as an image capturing means disposed near the liquid ejection unit 1002. The inkjet printer 1001 also includes an XY table 1003 serving as a scanning movement mechanism that moves the liquid ejection unit 1002 and the camera 1004 in the X and Y directions.

[0122] The inkjet printer 1001 also includes a control unit 1009. The control unit 1009 operates the XY table 1003 based on image editing software that edits images captured by the camera 1004 and a preset control program to eject ink from the liquid ejection unit 1002 and control printing on a surface to be printed. The inkjet printer 1001 also includes a drive unit 1011 that positions the camera 1004 and liquid ejection unit 1002 at predetermined positions based on control from the control unit 1009 to perform image capturing and printing operations.

[0123] The liquid ejection unit 1002 is equipped with multiple liquid ejection heads that eject ink toward the surface of the workpiece M. 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 1003, and ink dots ejected from each nozzle are ejected in the Z direction, which is perpendicular to the XY plane.

[0124] The liquid ejection unit 1002 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 11 (see FIG. 1) of the liquid ejection head, and ink discharged from a recovery port 12 (see FIG. 1) of the liquid ejection head is recovered into the ink tank.

[0125] If the distance between the nozzle surface of the liquid ejection head and the print surface of the workpiece M is about 20 cm, ink dots can be ejected onto the print surface of the workpiece M without any problems.

[0126] The XY table 1003 includes a Y-axis rail 1005 formed with a linear movement mechanism, and an X-axis movement mechanism 1006 that moves the Y-axis rail 1005 in the X direction while holding the Y-axis rail 1005 with two arms.

[0127] A liquid discharge unit 1002 and a camera 1004 (described later) are attached to a slider held by a Y-axis rail 1005. A shaft 1007 is provided on the X-axis movement mechanism 1006, and this shaft 1007 is held by a robot arm 1008. This robot arm allows the liquid discharge unit 1002 to be freely positioned at a predetermined position on the workpiece M where printing is to be performed.

[0128] For example, if the object to be painted M is an automobile, the robot arm 1008 can position it in an upper position as shown in Fig. 17 or in a lateral position. The operation of the robot arm 1008 is controlled based on a program stored in advance in the control unit 1009.

[0129] The camera 1004 is mounted on a slider on a Y-axis rail 1005 near the liquid discharge unit 1002, and moves in the X and Y directions while capturing images of a predetermined range of the surface to be printed of the object M at constant, minute intervals. The camera 1004 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 camera 1004 captures the multiple sub-divided images of the surface to be printed continuously and automatically according to a program pre-installed in the control unit 1009.

[0130] The control unit 1009 includes a storage device that records and saves various programs, data on captured images, data on images to be printed, etc., and a central processing unit that executes various processes in accordance with the programs. The control unit 1009 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.

[0131] The inkjet printer 1001 further includes a monitor 1010, which displays information input to the control unit 1009, processing results by the control unit 1009, and the like. As will be described later, the control unit 1009 uses image processing software to process the multiple pieces of subdivided image data captured by the camera 1004, and generates a composite print surface by projecting the non-flat print surface of the object M to be coated onto a flat surface. The control unit 1009 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.

[0132] 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 1002. This makes it possible to print a print image with no gaps between it and an already printed print image. Note that the photographing of multiple subdivided images by the camera 1004 and the printing by ejecting ink from the nozzles of each liquid ejection head of the liquid ejection unit 1002 are performed by a drive unit 1011 whose operation is controlled by the control unit 1009.

[0133] FIG. 18 is a diagram showing an example of an electrode manufacturing apparatus 700 as an apparatus for discharging liquid, which is equipped with the liquid discharge head of this embodiment. The electrode manufacturing apparatus 700 includes a discharge process section 710 that includes a process of applying a liquid composition to a printing substrate 704 having an object to be discharged to form a liquid composition layer, and a heating process section 730 that includes a heating process of heating the liquid composition layer to obtain an electrode mixture layer.

[0134] The printing substrate 704 on which the liquid composition layer is formed is not particularly limited as long as it is an object on which a layer having an electrode material is to be formed, and can be appropriately selected depending on the purpose. For example, an electrode substrate (current collector), an active material layer, a layer having a solid electrode material, etc. can be mentioned.

[0135] Furthermore, the discharge process unit 710 may be configured to form a layer having an electrode material by directly discharging a liquid composition, as long as it is possible to form a layer having an electrode material on the printing substrate 704. Alternatively, the discharge process unit 710 may be configured to form a layer having an electrode material by indirectly discharging a liquid composition. The heating process section 730 is a process for heating the liquid composition that has been discharged onto the printing substrate 704 in the discharge process section 710. The liquid composition layer can be dried by heating.

[0136] The electrode manufacturing apparatus 700 includes a transport section 705 that transports the printing substrate 704, and the transport section 705 transports the printing substrate 704 at a preset speed through the discharge process section 710 and the heating process section 730 in that order. There are no particular limitations on the method for manufacturing the printing substrate 704 having a discharge target such as an active material layer, and any known method can be selected as appropriate. The discharge process section 710 includes a printing device 281a that includes the liquid discharge head 1 of this embodiment that discharges a liquid composition onto the printing substrate 704. The apparatus also includes a storage container 281b that stores the liquid composition, and a supply tube 281c that supplies the liquid composition stored in the storage container 281b to the printing device 281a.

[0137] The storage container 281b stores the liquid composition 707, and the discharge process unit 710 discharges the liquid composition 707 from the printing device 281a and applies the liquid composition 707 onto the printing substrate 704 to form a thin film of the liquid composition layer. The storage container 281b may be configured as an integral part of the manufacturing apparatus for the electrode mixture layer, or may be configured as a removable part from the manufacturing apparatus for the electrode mixture layer. Alternatively, the storage container 281b may be a container used for adding the liquid to a storage container integrated with the manufacturing apparatus for the electrode mixture layer or a storage container removable from the manufacturing apparatus for the electrode mixture layer. Furthermore, the storage container 281b and the supply tube 281c can be arbitrarily selected as long as they can stably store and supply the liquid composition 707.

[0138] The heating process section 730 has a heating device 703 and includes a solvent removal step of heating and drying and removing the solvent remaining in the liquid composition layer with the heating device 703. This allows the formation of an electrode mixture layer. The heating process section 730 may perform the solvent removal step under reduced pressure.

[0139] The heating device 703 is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a substrate heater, an IR heater, a hot air heater, etc., and these may be combined. The heating temperature and time can be appropriately selected depending on the boiling point of the solvent contained in the liquid composition 707 and the thickness of the formed film.

[0140] When the liquid ejection head 1 of this embodiment is used in the electrode manufacturing apparatus 700, the liquid composition can be ejected to a targeted location on an object to be ejected. The electrode mixture layer can be suitably used, for example, as part of the configuration of an electrochemical element. The components other than the electrode mixture layer in the electrochemical element are not particularly limited, and known components can be appropriately selected, such as a positive electrode, a negative electrode, and a separator.

[0141] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0142] In the above description, an embodiment has been described in which the drive control device applies a voltage to a driver such as a piezoelectric element to open and close the needle valve 113. However, the present invention is not limited to this, and the needle valve 113 may be opened and closed by air pressure or hydraulic pressure. In this case, the drive pulse generated by the drive control device is a drive waveform for driving the air- or hydraulic-based pressurizing mechanism at a set pressure.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] The scanning movement mechanism includes the guide member alone, and the supply mechanism includes the tube alone and the loading unit alone.

[0148] 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.

[0149] 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.

[0150] 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).

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] For example, the present invention can also be used in a case where the nozzle plate 101 and the lower housing 10b are bonded together using a thermosetting adhesive. When bonding the nozzle plate 101 and the lower housing 10b together using a thermosetting adhesive, the laminated plate made up of the nozzle plate 101 and the lower housing is heated to harden the thermosetting adhesive, thereby bonding the nozzle plate 101 and the lower housing 10b together. When the temperature rises during this process, the nozzle plate 101 expands thermally, pushing in the positioning pins, which can cause the positioning pins 140 to tilt. This can prevent this from happening by applying the present invention. This makes it possible to suppress deterioration in positioning accuracy.

[0158] The above description is merely an example, and each of the following aspects provides unique effects. (Aspect 1) In a liquid ejection head 1 comprising a nozzle plate 101 having nozzles 111, a flow path member such as a lower housing 10b having a flow path 112 through which liquid ejected from the nozzles 111 flows, and a positioning member such as a positioning pin 140 that is inserted into a positioning hole 130a in the nozzle plate 101 and a positioning hole 131a in the flow path member to position the nozzle plate 101 to the flow path member, the positioning member has a predetermined gap with respect to both the positioning hole 130a in the nozzle plate 101 and the positioning hole 131a in the flow path member, and a fixing member 160a is provided that pushes the positioning member from a direction perpendicular to the insertion direction of the positioning member into the positioning hole, abutting the outer surface of the positioning member against the inner surface of at least one of the two positioning holes, thereby fixing the positioning member within the positioning hole in an attitude parallel to the insertion direction. By configuring the positioning member to be inserted into both the positioning hole of the nozzle plate and the positioning hole of the flow path member with a predetermined gap, it is possible to release the thermal expansion of the positioning member due to heating during diffusion bonding, thereby preventing the positioning member or the positioning hole from deforming and thereby preventing deterioration in the positioning accuracy of the nozzle plate relative to the flow path member. However, the following problems have arisen when the positioning member is inserted into the positioning hole of the flow path member with a gap therebetween. That is, even if the nozzle plate and the flow path member are made of the same material, their different heat capacities result in different heating rates, and when the temperature rises to 800 to 1000°C during diffusion bonding, the thermal expansion of the nozzle plate and the flow path member differs. In a configuration in which the nozzle plate and the flow path member are inserted into both the positioning holes of the nozzle plate and the flow path member with a predetermined gap, the nozzle plate or the flow path member that has a faster heating rate is pressed by the inner circumferential surface of the positioning hole, causing the positioning member to tilt within the positioning hole. As a result, the positional deviation of the nozzle plate relative to the flow path member exceeds the gap between the positioning member and the positioning hole, resulting in a problem of poor positioning accuracy. This problem is not limited to diffusion bonding and can similarly occur when bonding a nozzle plate and a flow path member using heat, such as thermal bonding. In contrast, in aspect 1, the positioning member is pushed in by the fixing member from a direction perpendicular to the insertion direction, and the outer peripheral surface of the positioning member abuts against the inner peripheral surface of the positioning hole, and is clamped and fixed in a position parallel to the insertion direction, and then heated. In this way, since the positioning member is clamped and fixed in a position parallel to the insertion direction, tilting of the positioning member due to pushing in of a member whose temperature rises quickly during diffusion bonding can be suppressed compared to when the positioning member is not clamped and fixed. Therefore, deterioration of positioning accuracy due to tilting of the positioning member can be suppressed.

[0159] (Aspect 2) In the first embodiment, the nozzle plate 101 is joined to a flow path member such as the lower housing 10b by diffusion bonding. This prevents the nozzle plate 101 from being joined at an angle in the liquid ejection direction relative to the flow path member, compared to when the nozzle plate 101 is joined to the lower housing 10b using adhesive, as described in the embodiment.

[0160] (Aspect 3) In the first or second embodiment, the nozzle plate 101, the flow path members such as the lower housing 10b, the positioning members such as the positioning pins 140, and the fixing member 160a are made of the same material. This allows the nozzle plate 101, flow path members such as the lower housing 10b, positioning members such as the positioning pin 140, and fixing member 160a to have the same linear expansion coefficient, as described in Example 1. This makes it possible to suppress the generation of stress due to differences in thermal expansion during bonding using heat, such as diffusion bonding, and to suppress deformation of the members.

[0161] (Aspect 4) In the third embodiment, the nozzle plate 101, flow path members such as the lower housing 10b, positioning members such as the positioning pin 140, and the fixing member 160a are made of the same type of stainless steel material. According to this, as explained in the first embodiment, corrosion can be suppressed and the life can be extended.

[0162] (Aspect 5) In any of aspects 1 to 4, the flow path member such as the lower housing 10b extends in a direction perpendicular to the insertion direction of the positioning member such as the positioning pin 140 into the positioning hole 131a, and has a communicating hole such as the female screw portion 150a that connects the outer surface of the flow path member to the positioning hole 131a of the flow path member and into which the fixing member 160a is inserted. According to this, as described in Example 1, a positioning member such as the positioning pin 140 inserted into the positioning hole 131a of a flow path member such as the lower housing 10b can be pushed in from a direction perpendicular to the insertion direction of the positioning member into the positioning hole by the fixing member inserted into the communicating hole. Therefore, the outer peripheral surface of the positioning member can be abutted against the inner peripheral surface of the positioning hole 131a of the flow path member, and the positioning member can be fixed in the positioning hole 131a of the flow path member in an attitude parallel to the insertion direction (Z direction).

[0163] (Aspect 6) In the fifth aspect, the communication hole has a female thread portion, and the fixing member 160a has a male thread portion that is screwed into the female thread portion. According to this, as described in Example 1, by screwing the fixing member 160a into a communication hole such as the female screw portion 150a, a positioning member such as the positioning pin 140 can be pushed in from a direction perpendicular to the insertion direction of the positioning member into the positioning hole. This allows the positioning member to be clamped and fixed in a posture parallel to the insertion direction (Z direction) between the fixing member 160a and the outer circumferential surface of the positioning hole of a flow path member such as the lower housing 10b.

[0164] (Aspect 7) In any of the first to sixth aspects, the nozzle plate 101 has a nozzle row in which a plurality of nozzles 111 are arranged, and both ends of the nozzle plate 101 in the nozzle arrangement direction (X direction) are positioned to a flow path member such as a lower housing. As a result, as described in Example 1, the nozzle plate 101 can be positioned relative to a flow path member such as the lower housing 10b in the nozzle arrangement direction (X direction), the liquid ejection direction (Z direction), and a direction perpendicular to both the nozzle arrangement direction (Y direction), and around the liquid ejection direction (Z direction).

[0165] (Aspect 8) In embodiment 7, the positioning hole arranged at one end of the nozzle plate 101 in the nozzle arrangement direction is a round hole, and the positioning hole arranged at the other end of the nozzle plate 101 in the nozzle arrangement direction is a long hole that is long in the nozzle arrangement direction. As explained in Example 2, this allows for accurate positioning in the nozzle arrangement direction (X direction), the liquid ejection direction (Z direction), and the direction (Y direction) perpendicular to both the nozzle arrangement direction and the liquid ejection direction (Z direction) using the positioning holes arranged on one end side of the nozzle arrangement direction of the nozzle plate 101. Furthermore, accurate positioning around the Z direction is possible using the positioning holes arranged on the other end side of the nozzle arrangement direction of the nozzle plate 101. Furthermore, by making the positioning hole on the other end side an elongated hole that is long in the nozzle arrangement direction (X direction), it is possible to prevent the positioning hole on the other end side of the nozzle plate from coming into contact with a positioning member such as a positioning pin due to thermal expansion of the nozzle plate when the temperature rises during diffusion bonding. This prevents the other end side from being restricted by the positioning member in terms of thermal expansion in the nozzle arrangement direction, and prevents deformation such as warping or rippling of the nozzle plate.

[0166] (Aspect 9) In any of aspects 1 to 6, the nozzle plate 101 has a nozzle row in which a plurality of nozzles 111 are arranged, and the nozzle plate 101 is positioned in a flow path member such as the lower housing 10b at three locations: both ends of the nozzle plate 101 in the nozzle arrangement direction (X direction) and a central portion located between the both ends in the nozzle arrangement direction; the positioning holes 130a and 130b arranged at both ends of the nozzle plate 101 in the nozzle arrangement direction are elongated holes that are long in the nozzle arrangement direction (X direction), and the positioning hole 130c arranged in the central portion in the nozzle arrangement direction is a circular hole. As explained in the third embodiment, this allows for accurate positioning in the nozzle arrangement direction (X direction) and in the direction (Y direction) perpendicular to both the liquid ejection direction (Z direction) and the nozzle arrangement direction (X direction) by using the positioning hole 130c located at the center of the nozzle arrangement direction of the nozzle plate 101. Furthermore, accurate positioning around the Z direction is possible by using the elongated positioning holes 130a and 130b located at both ends of the nozzle arrangement direction (X direction) of the nozzle plate 101. Furthermore, by making the positioning holes at both ends long holes in the nozzle arrangement direction (X direction), it is possible to prevent the positioning holes 130a, 130b at both ends of the nozzle plate from coming into contact with positioning members such as positioning pins 140 due to thermal expansion of the nozzle plate when the temperature rises during diffusion bonding. This prevents both ends from being restricted by the positioning members in terms of thermal expansion in the nozzle arrangement direction, and it is possible to prevent deformation such as warping or rippling of the nozzle plate.

[0167] (Aspect 10) In the eighth or ninth embodiment, only the positioning member, such as a positioning pin, inserted into the circular positioning hole is fixed by the fixing member 160a. According to this, the circular positioning hole serving as the primary positioning reference is more likely to come into contact with the positioning member due to thermal expansion of the nozzle when the temperature rises during diffusion bonding than the oblong positioning hole serving as the secondary positioning reference. Therefore, by fixing the positioning member, such as the positioning pin 140 inserted into the circular positioning hole, with a fixing member, it is possible to prevent the positioning member from tilting due to thermal expansion of the nozzle plate 101 when the temperature rises during diffusion bonding. On the other hand, the positioning hole inserted into the positioning hole of the long hole of the positioning secondary reference is not fixed by a fixing member and can move freely. As a result, when the positioning hole of the secondary reference abuts against a positioning member such as positioning pin 140 due to thermal expansion of the nozzle plate during temperature rise during diffusion bonding, the positioning pin moves, allowing for thermal expansion of the nozzle plate. As a result, deformation such as warping or rippling of the nozzle plate is suppressed, unlike Comparative Example 2 in which the positioning member inserted into the positioning hole of the secondary reference is also fixed with a fixing member.

[0168] (Aspect 11) In any of aspects 1 to 10, a second fixing member such as second fixing member 160b is provided, which fixes the positioning pin in the positioning hole by pushing the positioning member such as positioning pin 140 of fixing member 160a from a direction different from the direction in which the positioning member is pushed, with the outer surface of the positioning member abutting the inner surface of the positioning hole. As a result, as described in Example 3, positioning members such as the positioning pin 140 can be firmly fixed in a position parallel to the insertion direction (Z direction), and tilting of the positioning member when pressed by thermal expansion of the nozzle plate during temperature rise during diffusion bonding can be further suppressed.

[0169] (Aspect 12) In any of aspects 1 to 11, the nozzle 111 is provided with a valve member such as a needle valve 113 that opens and closes the nozzle 111, and a moving means such as a piezoelectric element 114 that moves the valve member between a closed position that blocks the nozzle 111 and an open position that opens the nozzle 111. As a result, as described in Example 1, it is possible to effectively suppress concentricity deviation, which is the positional deviation between the center of the nozzle 111 and the axial center of a valve member such as the needle valve 113, and it is possible to effectively suppress discharge deflection and sealing failure.

[0170] (Aspect 13) The liquid ejection heads used in the liquid ejection device were any of the liquid ejection heads according to the first to twelfth embodiments. This allows the liquid to be ejected in a good manner. [Explanation of symbols]

[0171] 1: Liquid ejection head 2: Connector part 10: Housing 10a: Upper housing 10b: Lower housing (flow path member) 11: Supply port 12: Collection port 20: Cover 30: Long hole 101: Nozzle plate 111: Nozzle 112: Flow path 113: Needle valve (valve member) 113a: Valve body 113b: O-ring 113c: Washer 114: Piezoelectric element 115: Holding member 121: Bearing 130a: Positioning hole on one end of the nozzle plate in the X direction 130b: Positioning hole on the other end of the nozzle plate in the X direction 130c: Positioning hole in the center of the nozzle plate in the X direction 131a: Positioning hole on one end of the lower housing in the X direction 131b: Positioning hole on the other end of the lower housing in the X direction 131c: Positioning hole in the center of the lower housing in the X direction 132: Valve through hole 140: Locating pin 150a: Female thread 150b: Second female screw part 160a: fixing member 160b: Second fixing member 200: Diffusion bonding equipment 201a: Lower pressure plate 201b: Upper pressure plate 202: Upper Ram 700: Electrode manufacturing equipment 1001: Inkjet printer L: Circulation passage P: Pump [Prior art documents] [Patent documents]

[0172] [Patent Document 1] Japanese Patent Application Publication No. 2023-171244

Claims

1. a nozzle plate having nozzles; a flow path member having a flow path through which the liquid discharged from the nozzle flows; a liquid ejection head including a positioning member that is inserted into a positioning hole of the nozzle plate and a positioning hole of the flow path member, and that positions the nozzle plate relative to the flow path member; the positioning member has a predetermined gap with respect to both the positioning hole of the nozzle plate and the positioning hole of the flow path member, A liquid ejection head characterized by including a fixing member that fixes the positioning member within the positioning hole in a position parallel to the insertion direction by pushing the positioning member from a direction perpendicular to the insertion direction of the positioning member into the positioning hole and abutting the outer surface of the positioning member against the inner surface of at least one of the two positioning holes.

2. 2. The liquid ejection head according to claim 1, The liquid ejection head is characterized in that the nozzle plate is joined to the flow path member by diffusion bonding.

3. 2. The liquid ejection head according to claim 1, The liquid ejection head is characterized in that the nozzle plate, the flow path member, the positioning member, and the fixing member are made of the same material.

4. 4. The liquid ejection head according to claim 3, A liquid ejection head, wherein the nozzle plate, the flow path member, the positioning member and the fixing member are made of the same type of stainless steel material.

5. 2. The liquid ejection head according to claim 1, The flow path member extends in a direction perpendicular to the insertion direction of the positioning member into the positioning hole, connects the outer surface of the flow path member with the positioning hole of the flow path member, and has a communication hole into which the fixing member is inserted.

6. 6. The liquid ejection head according to claim 5, The liquid ejection head is characterized in that the communication hole has a female thread portion, and the fixing member has a male thread portion that is screwed into the female thread portion.

7. 2. The liquid ejection head according to claim 1, the nozzle plate has a nozzle row in which a plurality of nozzles are arranged, A liquid ejection head, characterized in that both ends of the nozzle plate in the nozzle arrangement direction are positioned by the flow path member.

8. 8. The liquid ejection head according to claim 7, A liquid ejection head characterized in that the positioning hole arranged on one end side of the nozzle plate in the nozzle arrangement direction is a round hole, and the positioning hole arranged on the other end side of the nozzle plate in the nozzle arrangement direction is a long hole that is long in the nozzle arrangement direction.

9. 2. The liquid ejection head according to claim 1, the nozzle plate has a nozzle row in which a plurality of nozzles are arranged, the nozzle plate is positioned relative to the flow path member at three locations: both end portions of the nozzle plate in a nozzle arrangement direction; and a central portion located between the both end portions in the nozzle arrangement direction; A liquid ejection head characterized in that the positioning holes arranged at both ends of the nozzle plate in the nozzle arrangement direction are elongated holes that are long in the nozzle arrangement direction, and the positioning hole arranged in the center in the nozzle arrangement direction is a round hole.

10. 10. The liquid ejection head according to claim 8, A liquid ejection head characterized in that only the positioning member inserted into the positioning hole of the round hole is fixed by the fixing member.

11. 2. The liquid ejection head according to claim 1, A liquid ejection head characterized by providing a second fixing member that fixes the positioning member within the positioning hole by pushing the positioning member from a direction different from the direction in which the positioning member of the fixing member is pushed, so that the outer surface of the positioning member abuts the inner surface of the positioning hole.

12. 2. The liquid ejection head according to claim 1, A liquid ejection head comprising: a valve member that opens and closes the nozzle; and a moving means that moves the valve member between a closed position that closes the nozzle and an open position that opens the nozzle.

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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