Nozzle and nozzle unit

Abstract

To facilitate manufacturing of an elongated shaped nozzle from which a fluid is discharged, and provide a nozzle which can apply a fluid even onto a narrow area such as a space between electronic components.SOLUTION: A nozzle includes a base part mainly containing ceramic, and a through hole. The base part has a first part, a second part, and a third part. The first part has a columnar first outer wall surface. The second part has a conical second outer wall surface which is connected to the first outer wall surface and has a first outer diameter which decreases with distance from a first end surface. The third part has a columnar third outer wall surface which is connected to the second outer wall surface. The through hole has a first hole part, a second hole part, and a third hole part. The first hole part has a first hole diameter and is positioned in the first part. The second hole part has a second hole diameter and is positioned from the first part to the second part. The third hole part has a third hole diameter and is positioned from the second part to the third part. The second hole diameter decreases with distance from the first part. The third hole diameter is constant.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a nozzle and a nozzle unit. [Background technology]

[0002] In recent years, electronic devices have come to be equipped with a great number of electronic components. In addition, the size of electronic components has become smaller and finer, and the adhesive to be applied to the mounting board is very small. In addition, it is necessary to apply the adhesive etc. accurately in a narrow area. The invention described in Patent Document 1 is known as a nozzle for applying adhesive used when adhering the above-mentioned electronic components to a mounting board or the like (see Patent Document 1). The invention described in Patent Document 1 describes a nozzle made of a ceramic material, which is composed of a cylindrical portion (12 in Patent Document 1) and a tapered portion (13 in Patent Document 1) (see, for example, FIG. 2 in Patent Document 1, etc.). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-58886 A Summary of the Invention

[0004] In one embodiment of the present disclosure (1), the nozzle includes a base portion mainly made of ceramic and a through hole. The base portion has a first end face and a second end face located on the opposite side to the first end face. The through hole penetrates from the first end face to the second end face and has a central axis extending in a first direction. The base portion further includes a first portion, a second portion, and a third portion. The first portion has a first end face and a cylindrical first outer wall surface connected to the first end face and at least a portion of which is press-fitted into the fixing member. The second portion has a conical second outer wall surface connected to the first outer wall surface and having a first outer diameter that decreases as it moves away from the first end face in the first direction. The third portion has a second end face and a cylindrical third outer wall surface connected to the second outer wall surface and the second end face and having a second outer diameter equal to or smaller than the first outer diameter. The through hole further includes a first hole portion, a second hole portion, and a third hole portion. The first hole portion has a first hole diameter and is located in the first portion. The second hole portion has a second hole diameter and is located from the first portion to the second portion. The third hole portion has a third hole diameter and is located from the second portion to the third portion. The second hole diameter decreases with increasing distance from the first portion in the first direction. The third hole diameter is constant in the first direction.

[0005] (2) In the nozzle of (1) above, the first hole diameter is constant in the first direction.

[0006] (3) In the nozzle of (1) or (2) above, the first hole portion has a first inner wall surface connected to the first end surface. The second hole portion has a second inner wall surface connected to the first inner wall surface. The third hole portion has a third inner wall surface connected to the second inner wall surface. The second inner wall surface has a first end portion connected to the first inner wall surface and a second end portion connected to the third inner wall surface. In a cross-sectional view passing through the central axis and parallel to the first direction, when a straight line connecting the first end portion and the second end portion is defined as a first virtual line, the inclination θ1 of the second outer wall surface with respect to the central axis is equal to or greater than the inclination θ2 of the first virtual line with respect to the central axis.

[0007] (4) In the nozzle of (3) above, the surface roughness Ra1 of the second inner wall surface is greater than the surface roughness Ra2 of the third inner wall surface.

[0008] (5) In the nozzles of (1) to (4) above, the base portion is made mainly of zirconia.

[0009] (6) In the nozzles of (3) to (5) above, the second inner wall surface has an arc shape in a cross section passing through the central axis and parallel to the first direction.

[0010] (7) In the nozzles of (3) to (6) above, in a cross section passing through the central axis and parallel to the first direction, the inclination θ3 of the second inner wall surface with respect to the central axis is 10 to 20 degrees.

[0011] (8) In the nozzles of (3) to (7) above, in a cross-sectional view passing through the central axis and parallel to the first direction, the second outer wall surface and the third outer wall surface are connected via a first connection portion having an arc shape.

[0012] (9) In the nozzles of (1) to (8) above, when the dimension of the third portion in the first direction is L1, the third hole diameter is D3, and the second outer diameter is D13, L1≦378×[D13 3 -(D3 4 / D13).

[0013] (10) In the nozzles of (1) to (9) above, the base further has a fourth portion connected to the second end face. The fourth portion has a cylindrical fourth outer wall surface having a third outer diameter smaller than the second outer diameter. The third hole further extends from the third portion to the fourth portion.

[0014] (11) In the nozzle of (10) above, in a cross-sectional view passing through the central axis and parallel to the first direction, the third outer wall surface and the fourth outer wall surface are connected via a second connection portion having an arc shape.

[0015] (12) In the nozzle of (10) or (11) above, the dimension of the fourth portion in the first direction is equal to or less than half the combined dimension of the fourth portion and the third portion in the first direction.

[0016] (13) In the nozzles of (10) to (12) above, when the dimension of the fourth portion in the first direction is L2, the third hole diameter is D3, and the third outer diameter is D14, L2≦378×[D14 3 -(D3 4 / D14).

[0017] (14) In the nozzle of (13) above, when the combined dimension of the fourth and third parts in the first direction is L12 and the second outer diameter is D13, L12≦378×[D13 3 -(D3 4 / D13).

[0018] (15) A nozzle unit according to an embodiment of the present disclosure includes the nozzle according to any one of (1) to (14) above, and a fixing member. The fixing member has a first opening. At least a part of the first part of the nozzle is press-fitted into the first opening. [Brief description of the drawings]

[0019] [Figure 1] FIG. 1 is a perspective view of a nozzle according to an embodiment of the present disclosure. [Diagram 2] FIG. 2 is a plan view of a nozzle according to an embodiment of the present disclosure. [Diagram 3] FIG. 2 is a cross-sectional view of the nozzle shown in FIG. [Figure 4] FIG. 4 is an enlarged view of a main part A shown in FIG. [Diagram 5] 5 is an enlarged view of a main part B shown in FIG. [Figure 6] FIG. 2 is an exploded cross-sectional view of a nozzle and a nozzle unit according to an embodiment of the present disclosure. [Figure 7] FIG. 13 is a perspective view of a nozzle according to another embodiment of the present disclosure. [Figure 8] FIG. 8 is a cross-sectional view of the nozzle shown in FIG. 7 taken along line II-II. [Figure 9] 9 is an enlarged view of a main part C shown in FIG. 8. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] <Nozzle configuration> Hereinafter, some exemplary embodiments of the present disclosure will be described with reference to the drawings. Although any direction of the nozzle may be upward or downward, for convenience, a Cartesian coordinate system xyz is defined, and the negative side of the z direction is downward. In addition, in the following, the first direction refers to, for example, the z direction in the drawings. In addition, in this disclosure, plan view is a concept that includes planar perspective.

[0021] A nozzle 3 according to an embodiment of the present disclosure will be described with reference to Figures 1 to 5. The nozzle 3 includes a base 1 made mainly of ceramic, and a through hole 2.

[0022] As shown in Fig. 1 and Fig. 2, the base 1 has a first end surface 1a and a second end surface 1b located on the opposite side to the first end surface 1a. As the material of the base 1, for example, ceramic materials such as aluminum oxide sintered body, mullite sintered body, silicon carbide sintered body, aluminum nitride sintered body, silicon nitride sintered body, or glass ceramic materials can be used. The size of the base 1 in the z direction is, for example, 5 mm to 50 mm. Ceramic materials and glass ceramic materials are easier to process than general metal materials, and therefore the nozzle 3 can be easily manufactured.

[0023] The base 1 further has a first portion 11, a second portion 12, and a third portion 13. The first portion 11 has a first end face 1a and a first outer wall surface 111. The first outer wall surface 11 is a cylindrical surface that is connected to the first end face 1a and at least a portion of which is press-fitted into the fixing member 4. The size of the first portion 11 in the z direction is, for example, 0.5 mm to 10 mm.

[0024] The second portion 12 has a second outer wall surface 122. The second outer wall surface 122 is connected to the first outer wall surface 111 and is a conical surface having a first outer diameter D12 that decreases with increasing distance from the first end face 1a in the z direction (first direction). The size of the second portion 12 in the z direction is, for example, 1 mm to 45 mm. The size of the first outer diameter D12 is, for example, 0.1 mm to 5 mm. As shown in FIG. 2 and FIG. 3, in one embodiment, the first outer diameter D12 decreases at a constant rate with increasing distance from the first end face 1a in the z direction (first direction).

[0025] The third portion 13 has a second end surface 1b and a third outer wall surface 133. The third outer wall surface 133 is connected to the second outer wall surface 122 and the second end surface 1b, and is a cylindrical surface having a second outer diameter D13 that is equal to or smaller than the first outer diameter D12. The size of the third portion 13 in the z direction is, for example, 0.1 mm to 3 mm. The size of the second outer diameter D13 is, for example, 0.01 mm to 2 mm.

[0026] The through hole 2 penetrates from the first end face 1a to the second end face 1b and has a central axis C1 extending in the z direction (first direction). The through hole 2 may be manufactured by injection molding of a ceramic material or the like, or may be manufactured by punching a ceramic material formed in the outer shape of the nozzle 3. When a fluid such as an adhesive is applied using the nozzle 3, the fluid flows through the through hole 2 in the positive direction of the z axis. By pressurizing the fluid from the first end face 1a side, the fluid can pass through the first hole portion 21, the second hole portion 22, and the third hole portion 23 in this order and be discharged from the second end face 1b side. Here, examples of the fluid include conductive adhesives such as epoxy adhesives, acrylic adhesives, and silver paste, and cream solder. In this disclosure, the fluid is a concept that includes paste-like substances.

[0027] The through hole 2 further has a first hole portion 21, a second hole portion 22, and a third hole portion 23. The first hole portion 21 has a first hole diameter D1 and is located in the first portion 11. The size of the first hole diameter D1 is, for example, 0.5 mm to 4 mm.

[0028] The second hole portion 22 has a second hole diameter D2 and is located from the first portion 11 to the second portion 12. The second hole diameter D2 becomes smaller as it moves away from the first portion 11 in the z direction. The size of the second hole diameter D2 is, for example, 0.5 mm to 4 mm.

[0029] The third hole portion 23 has a third hole diameter D3 and is located from the second portion 12 to the third portion 13. The third hole diameter D3 is constant in the z direction. This improves the linearity of the fluid passing through the third hole portion 23 compared to when the third hole portion 23 has a tapered shape (the third hole diameter varies). The size of the third hole diameter D3 is, for example, 0.005 mm to 3 mm. In other words, the length of the third hole portion in the z direction is longer than the length of the third portion 13 in the z direction. Here, "constant" may include manufacturing errors.

[0030] The longer the third hole portion 23 is, the more the flow resistance to the fluid in the third hole portion 23 can be increased. When the flow resistance to the fluid increases, pressure is required to discharge the fluid. Therefore, by adjusting the length of the third hole portion 23, the flow resistance can be adjusted and the possibility that the fluid will unintentionally drip from the second end surface 1b of the nozzle 3 can be reduced. In addition, by adjusting the pressure on the fluid, the fluid such as an adhesive can be applied with high precision to a desired position using the nozzle 3. Here, when the viscosity of the fluid is, for example, 100,000 cP to 500,000 cP, the above-mentioned effect can be more effectively achieved.

[0031] Since the third hole portion 23 of the nozzle 3 is located from the second portion 12 to the third portion 13, it is easy to manufacture a nozzle 3 in which the length of the third portion 13 in the z direction is long while keeping the second outer diameter D13 of the third portion 13 small. For example, when manufacturing the nozzle 3 by a manufacturing method described below, the second outer wall surface 122 can be cut and polished to easily adjust the length of the third portion 13 in the z direction.

[0032] Furthermore, since the third portion 13 of the nozzle 3 has a long length in the z direction, when the nozzle 3 is used to apply adhesive to an electronic component and a mounting board, a fluid such as an adhesive flowing in the positive direction of the z axis of the through hole 2 can be applied precisely to the desired position.

[0033] As shown in Fig. 3, the first hole diameter D1 may be constant in the z direction. With this configuration, the length by which the nozzle 3 press-fitted into the fixing member 4 described below protrudes in the z direction (see Fig. 6) can be adjusted by cutting and polishing the first end face a1 to match the second opening diameter D42 of the second opening 42. This makes it easy to manufacture various nozzles 3 according to user needs.

[0034] 3, the first hole 21 and the second hole 22 may be continuous and flush with each other. Furthermore, in this case, when a second inner wall surface 222 described later is a straight line inclined with respect to the central axis C1 in a cross-sectional view (e.g., an xz plane or a yz plane) passing through the central axis C1 and parallel to the z direction, the inclination of the second inner wall surface 222 with respect to the central axis C1 may be the same as that of the first inner wall surface 211.

[0035] As shown in FIG. 3, the first hole 21 has a first inner wall surface 211 connected to the first end surface 1a. The second hole 22 has a second inner wall surface 222 connected to the first inner wall surface 211. The third hole 23 has a third inner wall surface 233 connected to the second inner wall surface 222. The second inner wall surface 222 has a first end 222a connected to the first inner wall surface 211 and a second end 222b connected to the third inner wall surface 233. In a cross-sectional view (for example, an xy plane) passing through the central axis C1 and parallel to the z direction, when a straight line connecting the first end 222a and the second end 222b is defined as a first virtual line T1, the inclination θ1 of the second outer wall surface 122 with respect to the central axis C1 may be equal to or greater than the inclination θ2 of the first virtual line T1 with respect to the central axis C1. That is, the thickness (the distance between the second inner wall surface 222 and the second outer wall surface 122) of at least a part of the second portion 12 of the nozzle 3 does not have to be constant. With the above-mentioned configuration, it is possible to reduce the possibility of the nozzle 3 being damaged when the second portion 12 (second outer wall surface 122) is gripped and the nozzle 3 is press-fitted into the first opening 41 of the fixing member 4 described below.

[0036] Moreover, the surface roughness Ra1 of the second inner wall surface 222 may be larger than the surface roughness Ra2 of the third inner wall surface 233. When the surface roughness Ra1 of the second inner wall surface 222 is the same as the surface roughness Ra2 of the third inner wall surface 233, the third hole diameter D3 is equal to or smaller than the second hole diameter D2, so that the third hole portion 23 has a larger flow resistance to the fluid than the second hole portion 22. Therefore, by making the surface roughness Ra1 of the second inner wall surface 222 larger than the surface roughness Ra2 of the third inner wall surface 233, the flow resistance of the fluid in the third hole portion 23 can be made closer to the flow resistance in the second hole portion 22. This can reduce the possibility that the timing of the fluid being discharged when pressure is applied to the fluid is shifted. Therefore, it can reduce the possibility that the application diameter of the fluid discharged from the second end surface 1b will vary. With this configuration, it can reduce the possibility that the fluid flowing through the through hole 2 will unintentionally drip from the second end surface 1b of the nozzle 3.

[0037] The base 1 may be mainly composed of zirconia. Here, the term "main component" in the present disclosure refers to at least the component with the highest content, for example, a component with a content of 90% or more. Since zirconia has a higher strength than aluminum oxide, etc., as shown in FIG. 5, the length of the third portion 13 in the z direction can be increased while the second outer diameter D13 is reduced. In addition, the thickness of the third portion 13 of the nozzle 3 (the distance between the third inner wall surface 233 and the third outer wall surface 133) can be reduced. Furthermore, since zirconia has superior wear resistance and chemical resistance compared to aluminum oxide, etc., the possibility of the nozzle 3 being worn or damaged can be reduced.

[0038] As shown in FIG. 3, the second inner wall surface 222 may have an arc shape in a cross section passing through the central axis C1 and parallel to the z direction. In one embodiment, the second inner wall surface 222 has an arc shape that is convex toward the central axis C1. This configuration can reduce the flow resistance of the fluid passing through the second hole portion 22. This can reduce the possibility that the timing of the fluid being discharged will be shifted when pressure is applied to the fluid. Therefore, it can reduce the possibility that the application diameter of the fluid discharged from the second end surface 1b will vary.

[0039] 3, in a cross-sectional view passing through the central axis C1 and parallel to the z direction, the inclination θ3 of the second inner wall surface 222 with respect to the central axis C1 may be 10 to 20 degrees. With this configuration, when manufacturing the nozzle 3 by the manufacturing method described later, it is possible to easily remove the injection-molded body of the nozzle 3 from the molding die.

[0040] 4, in a cross-sectional view passing through the central axis C1 and parallel to the z direction, the second outer wall surface 122 and the third outer wall surface 133 may be connected via a first connecting portion 123 having an arc shape. With this configuration, it is possible to reduce the possibility that stress will be concentrated on the first connecting portion 123 and the nozzle 3 will be damaged.

[0041] 4 and 5, when the dimension in the z direction of the third part 13 is L1 [mm], the second outer diameter is D13 [mm], and the third hole diameter is D3 [mm], the following formula (1) may be satisfied. With this configuration, the possibility that the third part 13 will break from the second part 12 can be further reduced.

[0042] In this case, the thickness of the third portion 13 (i.e., D13-D3) may be 0.04 mm or more. With this configuration, it is possible to reduce the possibility that the third portion 13 will be damaged when the nozzle 3 is processed or manufactured. L1≦378×[D13 3 -(D3 4 / D13)] ···(1)

[0043] (Other embodiments) A nozzle 3 according to another embodiment of the present disclosure will be described with reference to Figures 7 to 9. In the following, only configurations of the other embodiment that differ from the configuration of the previously described embodiment will be described, and other configurations will be denoted by the same reference numerals as the previously described embodiment and description thereof will be omitted.

[0044] In one embodiment, the base 1 may further have a fourth portion 14 connected to the second end surface 1b. The fourth portion 14 may have a cylindrical fourth outer wall surface 144 having a third outer diameter D14 smaller than the second outer diameter D13. The third hole portion 23 further extends from the third portion 13 to the fourth portion 14. That is, the fourth portion 14 having a smaller outer diameter may be connected to the tip of the third portion 13. With this configuration, even if the tip of the nozzle 3 is elongated while the diameter (third outer diameter D14) of the tip of the nozzle 3 is reduced, the possibility of the tip of the nozzle 3 (here, the part including the third portion 13 and the fourth portion 14) being damaged can be reduced. Such a nozzle 3 can enable application of a fluid to a narrower area.

[0045] In one embodiment, as shown in FIG. 9, the third hole diameter D3 of the third hole portion 23 in the fourth portion 14 may be the same as or different from the third hole diameter D3 of the third hole portion 23 in the third portion.

[0046] As shown in FIG. 9, in a cross-sectional view (for example, an xz plane or a yz plane) passing through the central axis C1 and parallel to the z direction, the third outer wall surface 133 and the fourth outer wall surface 144 may be connected via a second connecting portion 134 having an arc shape. With this configuration, it is possible to reduce a sudden change in dimension from the second outer diameter D13 to the third outer diameter D14, so that the strength of the fourth part 14 can be improved. In addition, even if an obstacle hits the fourth part 14 from the outside, it is possible to reduce the possibility that the fourth part 14 will break from the third part 13. Furthermore, when a fluid is poured into the nozzle 3, it is possible to reduce the possibility that the third part 13 and the fourth part 14 will be damaged by the pressure of the fluid. In the case of the above configuration, the second connecting portion 134 may coincide with the second end surface 1b.

[0047] More specifically, when the dimension of the fourth portion 14 in the z direction is L2 [mm], the third hole diameter D3 is D3 [mm], and the third outer diameter D14 is D14 [mm], the following formula (2) may be satisfied. In this case, the thickness of the fourth portion 14 (i.e., D14-D3) may be 0.04 [mm] or more. L2≦378×[D14 3 -(D3 4 / D14)] ···(2)

[0048] Furthermore, when the combined dimension in the z direction of the fourth portion 14 and the third portion 13 is L12 [mm] and the second outer diameter D13 is D13 [mm], the following formula (3) may be satisfied. In this case, the thickness of the third portion 13 (i.e., D13-D3) may be 0.04 [mm] or more. L12≦378×[D13 3 -(D3 4 / D13)] ···(3)

[0049] <Nozzle manufacturing method> Here, an example of a manufacturing method of the nozzle 3 will be described. In this example, a ceramic containing zirconia as a main component (zirconia-based ceramic) will be used as a constituent material of the nozzle 3. Note that the present disclosure is not limited to the following embodiment.

[0050] (1) First, a molding material for forming a molded body that is a prototype of the nozzle 3 is prepared. Specifically, the molding material is prepared by thoroughly mixing and pulverizing a mixed powder of zirconium oxide powder and yttrium oxide powder using a ball mill or the like, and then adding a binder to the pulverized material and mixing it. The mixed powder may be a mixture of 85-99 mass% zirconium oxide powder and 1-15 mass% yttrium oxide powder, particularly a mixture of 90-98 mass% zirconium oxide powder and 2-10 mass% yttrium oxide powder. The zirconium oxide powder may have a purity of 95% or more, particularly 98% or more.

[0051] (2) Next, the prepared molding material is used to obtain a molded body having a through hole 2. Specifically, the molding material is filled into a cavity of a molding die having a cavity including a structure for forming the through hole 2, and a molded body is obtained by injection molding at a predetermined pressure. Note that the method for obtaining the molded body is not limited to the above-mentioned injection molding, and methods such as press molding, cast molding, cold isostatic molding, and extrusion molding may also be used.

[0052] (3) Next, the obtained green body is fired to obtain a sintered body. Specifically, the obtained green body is degreased by being placed in a degreasing furnace at 500 to 600°C for 2 to 10 hours, and then the degreased green body is fired in an oxygen atmosphere at 1300 to 1500°C for 0.5 to 3 hours to obtain a sintered body.

[0053] (4) Next, the inner circumferential surface of the through hole 2 of the obtained sintered body is subjected to polishing or the like to form a third inner wall surface 233. Specifically, the nozzle 3 is rotated about the central axis C1 as the rotation axis, and an abrasive is pressed against the through hole 2 to form the third inner wall surface 233. Similarly to the third inner wall surface 233, the first inner wall surface 211 and the second inner wall surface 222 may also be subjected to polishing or the like. At this time, by using a grinding oil, it is possible to perform polishing while suppressing an increase in surface roughness.

[0054] (5) Next, the outer shape of the obtained sintered body is subjected to cutting, polishing, and the like to form a first outer wall surface 111, a second outer wall surface 122, and a third outer wall surface 133. In this manner, the nozzle 3 can be manufactured.

[0055] <Nozzle unit configuration> 6, the nozzle unit 5 includes a nozzle 3 and a fixed member 4. The fixed member 4 has a first opening 41. At least a part of the first portion 11 of the nozzle 3 is press-fitted into the first opening 41.

[0056] The material of the fixing member 4 may be, for example, a metal material. The first opening 41 may have a first opening diameter D41. The fixing member 4 may have a second opening 42 connected to the first opening 41. The second opening 42 has a second opening diameter D42. In this case, the second opening diameter D42 may be equal to or smaller than the first opening diameter D41. With this configuration, the second opening 42 serves as a guide, and the nozzle 3 press-fitted into the first opening 41 is fixed at a desired position. The second opening diameter D42 may be the same as the first hole diameter D1 of the nozzle 3.

[0057] When a fluid such as a conductive adhesive is applied to an object to be coated using the nozzle unit 5, the fluid is pressurized inside a pressurizing device (not shown) to which the fixing member 4 is attached, and this pressure pushes the fluid into the through hole 2 of the nozzle 3 via the second opening 42. The fluid is discharged from the second end surface 1b of the nozzle 3 via the through hole 2, and is applied to the object to be coated.

[0058] With this configuration, it is possible to easily manufacture a nozzle in which the portion from which the fluid is ejected has an elongated shape. Furthermore, with this configuration, it is possible to provide a nozzle that is capable of applying fluid to narrow areas such as between electronic components.

[0059] It should be noted that the various combinations of the characteristic parts in one embodiment are not limited to the examples of the above-mentioned embodiment, and the embodiments may be combined with each other. [Explanation of symbols]

[0060] 1 base 1a 1st end surface 1b 2nd end face 11 Part 1 111 First exterior wall 12 Part 2 122 Second outer wall 123 First Connection 13 Part 3 133 Third exterior wall 134 Second Connection 14 Part 4 144 4th exterior wall 2 Through holes 21 1st hole 211 First inner wall 22 2nd hole 222 Second inner wall 222a First end 222b Second end 23 3rd hole 233 Third Inner Wall C1 center axis T1 First virtual line D1 First hole diameter D2 Second hole diameter D3 3rd hole diameter D12 1st outer diameter D13 Second outer diameter D14 3rd outer diameter D41 1st opening diameter D42 Second opening diameter L1 Dimension of part 3 in the first direction L2 Dimension of part 4 in the first direction L12 Dimension in the first direction of part 4 and part 3 combined θ1 Inclination of the first virtual line θ2 Inclination of the second outer wall surface θ3 Inclination of the second inner wall surface 3 Nozzles 4 Fixing member 41 First opening 42 Second Opening 5 Nozzle unit

Claims

1. a base portion having a first end surface and a second end surface opposite to the first end surface, the base portion being mainly made of ceramic; a through hole extending from the first end surface to the second end surface and having a central axis extending in a first direction; The base portion is a first portion having the first end surface and a cylindrical first outer wall surface connected to the first end surface and at least a portion of which is press-fitted into a fixing member; a second portion having a conical second outer wall surface connected to the first outer wall surface and having a first outer diameter that decreases as it moves away from the first end surface in the first direction; a third portion including the second end surface and a cylindrical third outer wall surface connected to the second outer wall surface and the second end surface and having a second outer diameter equal to or smaller than the first outer diameter, The through hole is a first hole portion having a first hole diameter and located in the first portion; a second hole portion having a second hole diameter and located from the first portion to the second portion; a third hole portion having a third hole diameter and located from the second portion to the third portion, the second hole diameter decreases as the second hole diameter increases in the first direction away from the first portion, The nozzle, wherein the third hole diameter is constant in the first direction.

2. The nozzle of claim 1 , wherein the first hole diameter is constant in the first direction.

3. the first hole portion has a first inner wall surface connected to the first end surface, the second hole portion has a second inner wall surface connected to the first inner wall surface, the third hole portion has a third inner wall surface connected to the second inner wall surface, the second inner wall surface has a first end connected to the first inner wall surface and a second end connected to the third inner wall surface, In a cross-sectional view passing through the central axis and parallel to the first direction, When a straight line connecting the first end portion and the second end portion is defined as a first virtual line, The nozzle according to claim 1 , wherein an inclination θ1 of the first virtual line with respect to the central axis and an inclination θ2 of the second outer wall surface with respect to the central axis are equal to or less than the above.

4. The nozzle according to claim 3 , wherein a surface roughness Ra1 of the second inner wall surface is greater than a surface roughness Ra2 of the third inner wall surface.

5. The nozzle according to any one of claims 1 to 4, wherein the base portion is mainly composed of zirconia.

6. The nozzle according to claim 3 , wherein the second inner wall surface has an arc shape in a cross section passing through the central axis and parallel to the first direction.

7. 7. The nozzle according to claim 3, wherein in a cross-sectional view passing through the central axis and parallel to the first direction, an inclination θ3 of the second inner wall surface with respect to the central axis is 10 to 20 degrees.

8. 8. The nozzle according to claim 1, wherein, in a cross-sectional view passing through the central axis and parallel to the first direction, the second outer wall surface and the third outer wall surface are connected via a first connection portion having an arc shape.

9. The dimension of the third portion in the first direction is L1. The third hole diameter is D3, When the second outer diameter is D13, L1≦378×[D14 ３ - (D3 ４ / D14)].

10. The base portion further includes a fourth portion connected to the second end surface, The fourth portion has a cylindrical fourth outer wall surface having a third outer diameter smaller than the second outer diameter, The nozzle according to any one of claims 1 to 9, wherein the third hole portion further extends from the third portion to the fourth portion.

11. The nozzle according to claim 10 , wherein in a cross-sectional view passing through the central axis and parallel to the first direction, the third outer wall surface and the fourth outer wall surface are connected via a second connection portion having an arc shape.

12. The nozzle according to claim 10 or 11, wherein a dimension of the fourth portion in the first direction is equal to or less than half a combined dimension of the fourth portion and the third portion in the first direction.

13. The dimension of the fourth portion in the first direction is L2. The third hole diameter is D3, When the third outer diameter is D14, L2≦378×[D14 ３ - (D3 ４ / D14)].

14. The combined dimension of the fourth portion and the third portion in the first direction is L12, When the second outer diameter is D13, L12≦378×[D13 ３ - (D3 ４ / D13)].

15. A nozzle according to any one of claims 1 to 14; a fixing member having a first opening into which the first portion is press-fitted.

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