Two fluid nozzle, inner nozzle component, and outer nozzle component

Abstract

To provide a two fluid nozzle in which variation in spray characteristics is suppressed.SOLUTION: The two fluid nozzle 1 includes the guide portion 6 in which the inner nozzle 10 and the outer nozzle 70 can be relatively displaced in the first direction 101 by the sliding between the inner nozzle 10 and the outer nozzle 70 and the relative displacement between the inner nozzle 10 and the outer nozzle 70 is restrained in the second direction 102 orthogonal to the first direction 101, and the holding portion 9 in which the relative position between the inner nozzle 10 and the outer nozzle 70 can be restrained in the first direction 101.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a two-fluid nozzle, an inner nozzle component, and an outer nozzle component, and more particularly to a nozzle for spray drying a slurry containing ceramic powder. [Background technology]

[0002] Externally mixed two-fluid nozzles are known as nozzles for spraying powders and the like. For example, Patent Document 1 discloses a vortex atomizing nozzle including a nozzle body, a liquid feed pipe, and a joint member. In this vortex atomizing nozzle, gas is supplied from a second fluid supply port of the nozzle body. Liquid is supplied from a liquid supply port. The liquid supply port is formed between the nozzle body and a core member. The supplied gas and liquid are externally mixed in front of the nozzle. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-244997 Summary of the Invention [Problem to be solved by the invention]

[0004] The two-fluid nozzle of Patent Document 1 includes an inner nozzle and an outer nozzle. In the two-fluid nozzle shown in Patent Document 1, the nozzle body corresponds to the outer nozzle, and the core member corresponds to the inner nozzle.

[0005] In conventional two-fluid nozzles, the inner nozzle and outer nozzle are connected by screws. Therefore, the coaxiality between the inner nozzle and the outer nozzle changes depending on the machining accuracy when threading the inner nozzle and the outer nozzle. When the coaxiality between the inner nozzle and the outer nozzle changes, the spray characteristics change. Conventional two-fluid nozzles have the problem of being prone to variations in spray characteristics.

[0006] An object of the present invention is to provide a two-fluid nozzle in which variations in spray characteristics are suppressed. [Means for solving the problem]

[0007] The two-fluid nozzle of the present invention comprises a cylindrical inner nozzle extending in a first direction and having a first fluid path therein through which a first fluid flows, and a cylindrical outer nozzle extending in the first direction and surrounding the exterior of the inner nozzle and having a second fluid path between the exterior and interior of the inner nozzle through which a second fluid flows, wherein the inner nozzle and the outer nozzle can be displaced relative to each other in the first direction by sliding between the inner nozzle and the outer nozzle, and the nozzle has a guide portion that restricts relative displacement between the inner nozzle and the outer nozzle in a second direction perpendicular to the first direction, and a holding portion that can restrict the relative position of the inner nozzle and the outer nozzle in the first direction. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a two-fluid nozzle in which variations in spray characteristics are suppressed. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view of a two-fluid nozzle according to an embodiment of the present invention. [Figure 2] FIG. 2 is a perspective view of the inner nozzle according to the embodiment of the present invention. [Figure 3] FIG. 3 is a perspective view of the outer nozzle according to the embodiment of the present invention. [Figure 4] FIG. 4 is a perspective view of a holding member according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] (Outline of two-fluid nozzle) A two-fluid nozzle according to an embodiment of the present invention will be described with reference to the drawings. Fig. 1 is a cross-sectional view of a two-fluid nozzle 1 according to an embodiment of the present invention. As shown in Fig. 1, the two-fluid nozzle 1 includes an inner nozzle 10, an outer nozzle 70, and a holding member 50. The two-fluid nozzle 1 is configured by inserting the inner nozzle 10 into the outer nozzle 70.

[0011] (inner nozzle) FIG. 2 is a perspective view of the inner nozzle 10. As shown in FIGS. 1 and 2, the inner nozzle 10 has a substantially cylindrical shape. The space surrounded by the interior 19 of the inner nozzle 10 functions as a first fluid path 14. The first fluid path 14 is a flow path through which the first fluid flows. The direction in which the first fluid path 14 extends is referred to as a first direction 101.

[0012] The inner nozzle 10 has an inner opening 4. The inner opening 4 injects the first fluid flowing through the first fluid path 14 to the outside of the inner nozzle 10. The inner opening 4 is provided at one end of the inner nozzle 10 in the first direction 101.

[0013] (Front and rear direction) In the first direction 101, the direction toward the inner opening 4 is called a leading end direction 105. The direction opposite to the leading end direction 105 is called a trailing end direction .

[0014] (outer nozzle) 3 is a perspective view of the outer nozzle 70. As shown in FIGS. 1 and 3, the outer nozzle 70 has a substantially cylindrical shape. The outer nozzle 70 is disposed so as to surround the exterior 20 of the inner nozzle 10. The space between the interior 72 of the outer nozzle 70 and the exterior 20 of the inner nozzle 10 is called a second fluid path 82. A second fluid flows through the second fluid path 82.

[0015] The outer nozzle 70 has an outer opening 86. The outer opening 86 ejects the second fluid flowing through the second fluid path 82 to the outside of the inner nozzle 10. The outer opening 86 is provided at one end of the outer nozzle 70 in the first direction 101. The outer opening 86 surrounds the inner opening 4.

[0016] The inner nozzle 10 and the outer nozzle 70 have a guide portion 6 and a holding portion 9 .

[0017] (Information Department) The guide portion 6 is a portion that allows the inner nozzle 10 and the outer nozzle 70 to be displaced relative to each other in a first direction 101 due to sliding between the inner nozzle 10 and the outer nozzle 70. The guide portion 6 is also a portion that restricts the relative displacement between the inner nozzle 10 and the outer nozzle 70 in a second direction 102. The second direction 102 is a direction perpendicular to the first direction 101.

[0018] (holding member) FIG. 4 is a perspective view of the holding member 50. As shown in FIGS. 1 and 4, the holding member 50 has a substantially cylindrical shape. A second screw 24 is provided on the outside of the holding member 50. The second screw 24 is a screw that mates with the first screw 76. The first screw 76 is a screw that is provided on the interior 72 of the outer nozzle 70. The holding member 50 abuts against the inner nozzle 10. The holding member 50 is a member that can relatively displace the inner nozzle 10 and the outer nozzle 70 in a first direction 101.

[0019] (holding part) The holding portion 9 is a portion that can restrict the relative positions of the inner nozzle 10 and the outer nozzle 70 in the first direction 101.

[0020] Restraint by the retaining portion 9 is achieved by the engagement between the second screw 24 and the first screw 76, the abutment between the retaining member 50 and the inner nozzle 10, and the abutment between the retaining member 50 and the positioning portion 8. The retaining member 50 is a member that abuts against the inner nozzle 10 and can displace the inner nozzle 10 and the outer nozzle 70 relative to each other in the first direction 101. The positioning portion 8 is a portion that restrains the inner nozzle 10 and the outer nozzle 70 at a predetermined position in the first direction 101.

[0021] (1st fluid) As shown in FIG. 1 , a flow path is formed in the interior 52 of the holding member 50. This flow path is referred to as the third fluid path 15. The opening of the third fluid path 15 in the rear end direction 106 is referred to as the rear end opening 30. The direction in which the first fluid path 14 extends is the same as the direction in which the third fluid path 15 extends. The third fluid path 15 and the first fluid path 14 are linearly connected. A first fluid is supplied to the first fluid path 14 from the rear end opening 30 via the third fluid path 15. The first fluid may be, for example, a liquid. The first fluid passes through the first fluid path 14 and is ejected from the inner opening 4. However, the third fluid path 15 does not necessarily have to be formed directly on the surface of the interior 52 of the holding member 50. For example, a tubular member having the third fluid path 15 therein may be connected to the first fluid path 14 via the interior 52 of the holding member 50.

[0022] (Second fluid) 1 and 3, the outer nozzle 70 is provided with a second fluid supply port 80. A second fluid is supplied to a second fluid path 82 via the second fluid supply port 80. The second fluid may be a gas such as air. The second fluid passes through the second fluid path 82 and is ejected from an outer opening 86.

[0023] (Notches and openings) 2, an inner sliding surface 26 is provided on the rear end direction 106 side of the inner tip portion 22. An inner tip portion 22 is provided at the end of the inner tip portion 22 in the tip direction 105. A notch 28 is formed in the inner tip portion 22.

[0024] (Opening) 3, the end portion of the outer nozzle 70 on the side of the tip direction 105 is called an outer tip portion 74. An outer opening portion 86 is provided in the outer tip portion 74.

[0025] 1, the outer tip portion 74 and the inner tip portion 22 abut on the tip direction 105 side of the two-fluid nozzle 1. A part of the notch portion is covered by the outer tip portion 74.

[0026] (spout) The outlet of the two-fluid nozzle 1 is called the outlet 3. The outlet 3 is mainly composed of an inner opening 4 and an outer opening 86. The first fluid is ejected from the inner opening 4. The second fluid is ejected from a notch 28 that opens in the outer opening 86. The first fluid and the second fluid are mixed externally in front of the outlet 3.

[0027] (Assembly of inner and outer nozzles) 1, when the inner nozzle 10 and the outer nozzle 70 are assembled, the inner nozzle 10 and the outer nozzle 70 abut mainly at the guide portion 6 and the holding portion 9. The relative position of the inner nozzle 10 and the outer nozzle 70 in the first direction 101 is restrained mainly by the holding portion 9. The relative displacement of the inner nozzle 10 and the outer nozzle 70 in the second direction 102 is restrained mainly by the guide portion 6.

[0028] (Restraint of the relative position between the inner nozzle and the outer nozzle in the first direction) The following describes how the holding portion 9 restricts the relative positions of the inner nozzle 10 and the outer nozzle 70 in the first direction. First, the position stopper 8 included in the holding portion 9 will be described.

[0029] (position stopper) At the position stopper 8, the inner nozzle 10 and the outer nozzle 70 abut in the first direction 101. More specifically, the exterior 20 of the inner nozzle 10 abuts on the interior 72 of the outer nozzle 70. The position stopper 8 includes an inner tip portion 22 and an outer tip portion 74. The inner tip portion 22 and the outer tip portion 74 abut on the tip direction 105 side of the two-fluid nozzle 1.

[0030] Specifically, the outer tip portion 74 of the outer nozzle 70 and / or the conical tip inner surface 73 of the outer opening 86 come into contact with the inner tip portion 22 of the inner nozzle 10 and / or the conical tip outer surface 23 of the inner opening 4. This restrains the positions of the outer nozzle 70 and the inner nozzle 10 in the first direction 101. Note that the tip outer surface 23 comes into contact with the inner tip portion 22 and / or the tip outer surface 23 in a portion where the notch 28 is not formed.

[0031] When the outer tip portion 74 and / or tip inner surface 73 abuts against the inner tip portion 22 and / or tip outer surface 23, the relative positions of the inner nozzle 10 and the outer nozzle 70 in the first direction 101 are restricted.

[0032] The position stopper 8 is not limited to the inner tip portion 22 and the outer tip portion 74. The position stopper 8 can be provided at any position where the inner nozzle 10 and the outer nozzle 70 abut in the first direction 101.

[0033] When the inner nozzle 10 and the outer nozzle 70 abut on a surface, the abutting surface does not need to be perpendicular to the first direction 101. The abutting surface between the inner nozzle 10 and the outer nozzle 70 only needs to be parallel to the first direction 101.

[0034] (First screw and retaining member) The first screw 76 and the holding member 50 included in the holding portion 9 will now be described. The second screw 24 of the holding member 50 engages with the first screw 76. This engagement allows the inner nozzle 10 and the outer nozzle 70 to be displaced relative to each other in the first direction 101 and to be held at a predetermined displacement.

[0035] (Restraint of relative displacement between the inner nozzle and the outer nozzle in the second direction) The following describes how the guide portion 6 restricts relative displacement between the inner nozzle 10 and the outer nozzle 70 in the second direction. As shown in FIG. 1, the guide portion 6 includes an inner sliding surface 26 and an outer sliding surface 78. The outer sliding surface 78 is provided inside 72 of the outer nozzle 70. The inner sliding surface 26 and the outer sliding surface 78 can slide in the first direction while in contact with each other. The inner sliding surface 26 and the outer sliding surface 78 are substantially smooth surfaces.

[0036] (Runout tolerance) The runout tolerance of the guide portion 6 will now be described. The runout tolerance of the guide portion 6 is smaller than the runout tolerance of the first screw 76 and the retaining member 50. In more detail, the runout tolerance of the inner sliding surface 26 and the outer sliding surface 78 is smaller than the runout tolerance of the first screw 76 and the second screw 24.

[0037] The runout tolerance of the guide portion 6 can be expressed, for example, as follows, based on JIS B 0401-1 and JIS B 0401-2. In a commonly used hole reference fit, it is preferable that the tolerance class of the outer sliding surface 78 of the outer nozzle 70 (as a hole) be the reference hole tolerance class H7, and the tolerance class of the inner sliding surface 26 of the inner nozzle 10 (as a shaft) be the shaft tolerance class g6. This results in a fit that corresponds to a "sliding fit" type of "clearance fit." The combination of hole tolerance class and shaft tolerance class is not limited to the above-mentioned H7g6, but may also be, for example, H7h6, H6 and h5, H8 and h7, H8 and h8, H9 and h9, etc.

[0038] In contrast, the rattle caused by the gap between the first screw 76 and the holding member 50 is approximately 60 μm on one side of the first screw 76 according to JIS B 0205, which is larger than the gap between the guide portion 6 and the outer sliding surface 78.

[0039] (surface roughness) The surface roughness of the guide portion 6 will now be described. The surface roughness values ​​of the inner sliding surface 26 and the outer sliding surface 78 of the guide portion 6 are smaller than the surface roughness value of the inner portion 72 of the outer nozzle 70 other than the outer sliding surface 78. The surface roughness value is the arithmetic mean roughness (Ra) value specified in JIS B 0601 and JIS B 0031. For example, the surface roughness of the inner sliding surface 26 and the outer sliding surface 78 is preferably in the range of Ra 1.0 to 10 μm, more preferably 1.0 to 5.0 μm, and most preferably 1.0 to 2.0 μm. In this embodiment, Ra is set to 1.6 μm. The surface roughness of the inner portion 72 of the outer nozzle 70 other than the outer sliding surface 78 is equal to or greater than the outer sliding surface 78 of the outer nozzle 70, and Ra can be set to 10 μm or more, for example, 10 to 20 μm.

[0040] (roundness) The roundness of the guide portion 6 will now be described. Assume that the inner sliding surface 26 and the outer sliding surface 78 of the guide portion 6 are cylindrical. The roundness values ​​of the inner sliding surface 26 and the outer sliding surface 78 are smaller than the roundness value of the interior of the outer nozzle 70 other than the outer sliding surface 78. The roundness value is the roundness value specified in JIS B 0621. For example, the roundness values ​​of the inner sliding surface 26 and the outer sliding surface 78 can be 0.001 to 0.030, more preferably 0.005 or less, and the roundness value of the interior 72 of the outer nozzle 70 other than the outer sliding surface 78 can be 0.003 or more.

[0041] (diameter and length of sliding surface) The diameter and length of the sliding surface of the guide portion 6 will be described. Assume that the inner nozzle 10 and the outer nozzle 70 are restrained at a predetermined position in the first direction 101 by the positioning stopper 8. Assume that the inner sliding surface 26 and the outer sliding surface 78 of the guide portion 6 are cylindrical. As shown in FIG. 1 , the portion where the inner sliding surface 26 and the outer sliding surface 78 face each other is referred to as the sliding surface facing portion 61. The length of the sliding surface facing portion 61 in the first direction 101 is referred to as length L. The inner diameter of the outer sliding surface 78 at the sliding surface facing portion 61 is referred to as diameter D. The length L is 0.2 times or more, preferably 0.5 times or more, and more preferably 0.8 times or more, of the diameter D. The diameter D can be, for example, 18 mm. The length L can be, for example, 15 mm.

[0042] If the guide portion 6 satisfies the above-mentioned requirements, the axes of the outer nozzle 70 and the inner nozzle 10 can be aligned accurately.

[0043] Furthermore, in the two-fluid nozzle 1, the inner sliding surface 26 that constitutes part of the guide portion 6 and the second screw 24 that constitutes part of the holding portion 9 are provided on different components. The inner sliding surface 26 is provided on the inner nozzle 10. The second screw 24 is provided on the holding member 50. This can improve the coaxiality between the inner nozzle 10 and the outer nozzle 70. This is because separate components can restrain the relative position of the inner nozzle 10 and the outer nozzle 70 in the first direction 101 and restrain the relative displacement in the second direction 102.

[0044] (axial force) When the holding member 50 is fastened to the outer nozzle 70, a force can be applied to the inner nozzle 10 toward the nozzle 3 parallel to the first direction 101. This force is called the axial force. By controlling the axial force according to the fastening state of the holding member 50, the clearance state or stress deformation between the inner tip portion 22 and the outer tip portion 74 can be maintained within an appropriate range. This has the effect of allowing the fastening of the holding member 50 to be adjusted, thereby controlling the clearance state between the inner nozzle 10 and the outer nozzle 70, which has a large impact on the variation in spray characteristics, within an appropriate range by adjusting the axial force of the holding member 50.

[0045] Stabilizing the contact state between the inner tip portion 22 and the outer tip portion 74 reduces variations in the cross-sectional area of ​​the notch 28 that opens at the outer opening 86. The notch 28 is a passage for a second fluid, such as compressed air. With the two-fluid nozzle 1 of this embodiment, the clearance of the passage for the second fluid can be stabilized even when multiple two-fluid nozzles 1 are produced or when they are repeatedly assembled. This reduces variations in the spray characteristics of each two-fluid nozzle 1.

[0046] Although the present invention has been described above as an embodiment, it is not limited to the above-described embodiment, and various changes, modifications, and combinations are possible.

[0047] (Variation 2) A modified example of the two-fluid nozzle 1 will now be described. In the two-fluid nozzle 1 of the modified example 2, the retaining portion 9 has a first screw 76 provided on the interior 72 of the outer nozzle 70 so that the inner nozzle 10 and the outer nozzle 70 can be displaced relative to each other in the first direction 101, a second screw 24 that engages with the first screw 76 provided on the exterior 20 of the inner nozzle 10, and a nut member having a third screw provided therein that engages with the second screw 24 that clamps and restrains the inner nozzle 10 and the outer nozzle 70 in the first direction 101 with the positioning portion 8. In the two-fluid nozzle 1 of the modified example 2, the torsional force in restraining the inner nozzle and the outer nozzle is suppressed, making the relative position of the inner nozzle and the outer nozzle more accurate.

[0048] (Variation 3) A third variation of the two-fluid nozzle 1 will now be described. The two-fluid nozzle 1 of the third variation does not include a retaining member 50. In the two-fluid nozzle 1 of the third variation, the outer nozzle 70 does not include a first screw 76. A slit extending in the first direction is formed at the end of the outer nozzle 70 in the rear end direction 106. A tightening member is provided on the outside of the portion of the outer nozzle 70 where the slit is formed, so that the diameter of the outer nozzle 70 can be reduced. By tightening the tightening member to reduce the diameter of the outer nozzle 70, the relative positions of the outer nozzle 70 and the inner nozzle 10 in the first direction 101 are constrained. In the two-fluid nozzle 1 of the third variation, the elastic stress caused by the slit further strengthens the constraining of the inner nozzle and the outer nozzle.

[0049] <1> a cylindrical inner nozzle extending in a first direction and having a first fluid path therein through which a first fluid flows; and a cylindrical outer nozzle extending in the first direction and surrounding the exterior of the inner nozzle and having a second fluid path between the exterior and interior of the inner nozzle through which a second fluid flows, wherein the inner nozzle and the outer nozzle can be displaced relative to each other in the first direction by sliding between the inner nozzle and the outer nozzle, and the nozzle has a guide section that restricts relative displacement between the inner nozzle and the outer nozzle in a second direction perpendicular to the first direction, and a holding section that can restrict the relative position of the inner nozzle and the outer nozzle in the first direction.

[0050] <2> the inner nozzle is provided at one end in the first direction and includes an inner opening portion that ejects the first fluid flowing through the first fluid path, the outer nozzle includes an outer opening that is provided at one end in the first direction, surrounds the inner opening, and ejects the second fluid flowing through the second fluid path to the outside of the inner nozzle. <1> The two-fluid nozzle according to claim 1.

[0051] <3> The holding portion is a first screw provided inside the outer nozzle; a holding member having a second screw provided on the outside thereof and engaging with the first screw, the holding member contacting the inner nozzle and displacing the inner nozzle and the outer nozzle relative to each other in the first direction; a position stopper that restrains the inner nozzle and the outer nozzle at a predetermined position in the first direction, <1> or <2> The two-fluid nozzle according to claim 1.

[0052] <4> a runout tolerance value due to the guide portion is smaller than a runout tolerance value due to the first screw and the holding member; <3> The two-fluid nozzle according to claim 1.

[0053] <5> the conical inner surface of the tip end and / or opening of the outer nozzle and the conical outer surface of the tip end and / or opening of the inner nozzle come into contact with each other to restrain the inner nozzle at a position in the first direction; <1> from <4> 10. The two-fluid nozzle according to claim 9, wherein the nozzle is a nozzle having a diameter of 100 mm or less.

[0054] <6> a runout tolerance value due to the inner sliding surface and the outer sliding surface of the guide portion is smaller than a runout tolerance value due to the outer nozzle and the pressing member; <1> from <5> 10. The two-fluid nozzle according to claim 9, wherein the nozzle is a nozzle having a diameter of 100 mm or less.

[0055] <7> the surface roughness values ​​of the inner sliding surface and the outer sliding surface of the guide portion are smaller than the surface roughness value of the inside of the outer nozzle other than the outer sliding surface; <1> from <6> 10. The two-fluid nozzle according to claim 9, wherein the nozzle is a nozzle having a diameter of 100 mm or less.

[0056] <8> an inner sliding surface and an outer sliding surface of the guide portion are cylindrical, and the values ​​of roundness of the inner sliding surface and the outer sliding surface are smaller than the value of roundness of the inside of the outer nozzle other than the outer sliding surface; <1> from <7> 10. The two-fluid nozzle according to claim 9, wherein the nozzle is a nozzle having a diameter of 100 mm or less.

[0057] <9> In a state in which the inner nozzle and the outer nozzle are restrained at predetermined positions in the first direction by the position stopper, the inner sliding surface and the outer sliding surface of the guide portion are cylindrical, and the opposing cylindrical sliding surfaces have a diameter D and a length L, where the length L is 0.2 times or more the diameter D. <3> The two-fluid nozzle according to claim 1.

[0058] <10> The holding portion is a first screw provided inside the outer nozzle so that the inner nozzle and the outer nozzle can be displaced relative to each other in the first direction; a second screw provided on the outside of the inner nozzle and engaging with the first screw; a nut member having a third screw provided therein that engages with the second screw that clamps and restrains the inner nozzle and the outer nozzle in the first direction using a position stopper portion, <1> from <9> 10. The two-fluid nozzle according to claim 9, wherein the nozzle is a nozzle having a diameter of 100 mm or less. [Explanation of symbols]

[0059] 1 fluid nozzle 3 spout 4 Inner opening 6 Information Department 8 Position stop 9 Holding part 10 Inner nozzle 14 First fluid path 15 Third fluid path 19 Inside 20 External 22 Inner tip 23 Tip outer surface 24 Second screw 26 Inner sliding surface 28 Notch 30 Rear end opening 50 holding member 52 Inside 61 sliding surface opposing part 70 outer nozzle 72 Internal 73 Tip inner surface 74 outer tip 76 First screw 78 Outer sliding surface 80 2nd fluid supply port 82 Second fluid path 86 outer opening 101 1st direction 102 Second direction 105 Tip direction 106 Rear end direction

Claims

1. a cylindrical inner nozzle extending in a first direction and having a first fluid path therein through which a first fluid flows; a cylindrical outer nozzle extending in the first direction and surrounding the outside of the inner nozzle, the outer nozzle having a second fluid path between the outside and the inside of the inner nozzle through which a second fluid flows; The inner nozzle and the outer nozzle are a guide portion that allows the inner nozzle and the outer nozzle to be displaced relative to each other in the first direction by sliding between the inner nozzle and the outer nozzle, and that restricts relative displacement between the inner nozzle and the outer nozzle in a second direction perpendicular to the first direction; a holding portion that can restrain the relative position of the inner nozzle and the outer nozzle in the first direction.

2. the inner nozzle is provided at one end in the first direction and includes an inner opening portion that ejects the first fluid flowing through the first fluid path; 2. The two-fluid nozzle according to claim 1, wherein the outer nozzle includes an outer opening provided at one end in the first direction, surrounding the inner opening, and ejecting the second fluid flowing through the second fluid path outside the inner nozzle.

3. The holding portion is a first screw provided inside the outer nozzle; a holding member having a second screw provided on the outside thereof and engaging with the first screw, the holding member contacting the inner nozzle and displacing the inner nozzle and the outer nozzle relative to each other in the first direction; The two-fluid nozzle according to claim 1 , further comprising a position stopper that restrains the inner nozzle and the outer nozzle at predetermined positions in the first direction.

4. The two-fluid nozzle according to claim 3 , wherein a value of the runout tolerance of the guide portion is smaller than a value of the runout tolerance of the first screw and the holding member.

5. 3. The two-fluid nozzle according to claim 1, wherein the conical inner surface of the tip and / or opening of the outer nozzle abuts against the conical outer surface of the tip and / or opening of the inner nozzle, thereby restraining the nozzle in a position in the first direction.

6. 3. The two-fluid nozzle according to claim 1, wherein a runout tolerance between the inner sliding surface and the outer sliding surface of the guide portion is smaller than a runout tolerance between the outer nozzle and the pressing member.

7. 3. The two-fluid nozzle according to claim 1, wherein the surface roughness values ​​of the inner sliding surface and the outer sliding surface of the guide portion are smaller than the surface roughness value of the inside of the outer nozzle other than the outer sliding surface.

8. 3. The two-fluid nozzle according to claim 1, wherein the inner sliding surface and the outer sliding surface of the guide portion are cylindrical, and the circularity values ​​of the inner sliding surface and the outer sliding surface are smaller than the circularity value of the interior of the outer nozzle other than the outer sliding surface.

9. 4. The two-fluid nozzle according to claim 3, wherein, when the position stop portion restrains the inner nozzle and the outer nozzle at a predetermined position in the first direction, the inner sliding surface and the outer sliding surface of the guide portion are cylindrical, and the opposing cylindrical sliding surfaces have a diameter D and a length L, where the length L is 0.2 times or more the diameter D.

10. The holding portion is a first screw provided inside the outer nozzle so that the inner nozzle and the outer nozzle can be displaced relative to each other in the first direction; a second screw provided on the exterior of the inner nozzle and engaging with the first screw; 3. The two-fluid nozzle according to claim 1, further comprising: a nut member having a third screw provided therein that engages with the second screw that clamps and restrains the inner nozzle and the outer nozzle in the first direction using a position stop portion.

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