Blast Nozzle

Abstract

To provide a blast nozzle which can easily perform blast processing to a processed surface in a narrow part while inhibiting reduction of its use life.SOLUTION: A blast nozzle 10 has: a nozzle body 11 including a first passage 11b for circulating a blast medium BM; and a head part 12 provided at a downstream side tip of the nozzle body 11 and including a second passage 12b in which one end communicates with the downstream side of the first passage 11b and the other end serves as a jet port 12a which jets the blast medium BM to the outside. The nozzle body 11 has a straight tube shape in which an internal space extending linearly forms the first passage 11b. The head part 12 has a curve surface part 12c, where at least a part of the second passage 12b forms a curved passage so that an opening direction D2 of the jet port 12a is different from an extension direction D1 of the first passage 11b, therein. Further, a thickness T2a of at least a part of a wall part of the head part 12 is larger than a thickness T1a of at least a part of a wall part of the nozzle body 11.SELECTED DRAWING: Figure 3

Description

[Technical Field]

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

[0002] Conventionally, there is a blasting device that performs blasting on a workpiece. The blasting device includes a blast gun that uses compressed air to spray blasting media such as abrasive grains onto the workpiece. Patent Document 1 discloses technology related to a blast gun that includes a conduit that introduces compressed air into the main body, a blasting material supply tube that introduces blasting material (blasting media) into the main body, and a spray nozzle. Here, the extension directions of the compressed air conduit and the spray nozzle are aligned in a straight line along the extension direction of the main body. Meanwhile, the blasting material supply tube is connected to the side of the main body so that the extension direction of the blasting material supply tube is perpendicular to the extension direction of the main body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-187069 Summary of the Invention [Problem to be solved by the invention]

[0004] In the blast gun disclosed in Patent Document 1, the extension direction of the compressed air conduit is the same as the extension direction of the main body, but the extension direction of the blast material supply tube is different from the extension direction of the main body. Furthermore, the injection nozzle is a straight tube, and the length from the main body to the tip of the injection nozzle is set to be relatively short. Therefore, for example, if the surface to be processed is in a narrowed portion of the workpiece, at least one of the compressed air conduit or the blast material supply tube may interfere with the workpiece, preventing the operator from reaching the injection nozzle to the desired position near the surface to be processed.

[0005] To address this issue, a possible solution is to use a curved nozzle, instead of the injection nozzle disclosed in Patent Document 1, as a blast nozzle for cases where the workpiece surface is located in a constricted area. Using a blast gun with a curved nozzle connected to it allows the operator to perform blast injection while inserting the curved nozzle into the constricted area of ​​the workpiece, which may enable blast processing of the workpiece surface located in the constricted area. However, when using a curved nozzle, the curved surface inside the curved nozzle is prone to wear because the blast media sucked in by compressed air inside the blast gun body is sprayed with great force. This may result in a shortened nozzle life.

[0006] Therefore, an object of the present disclosure is to provide a blast nozzle that can easily perform blast processing on a work surface located in a narrowed section while suppressing a decrease in service life. [Means for solving the problem]

[0007] One aspect of the present disclosure is a blast nozzle connected to a blast gun body, comprising: a nozzle body including a first flow path through which blasting media introduced from the blast gun body flows; and a head portion including a second flow path provided at the downstream tip of the nozzle body, one end of which communicates with the downstream side of the first flow path and the other end of which is an ejection port for ejecting the blasting media to the outside. Yes death, The nozzle body and head are integrally molded. The nozzle body has an internal space extending linearly as a first flow path. The thickness of the wall portion forming the first flow path is constant. straight pipe shape The part that becomes the head portion has a curved surface portion therein that makes at least a part of the second flow path a curved flow path so that the opening direction of the injection port is a direction different from the extension direction of the first flow path, the thickness of an outer wall portion constituting a curved surface portion located on an extension of the extension direction of the first flow path, which is at least a part of the wall portion of the head portion, is thicker than the thickness of a wall portion forming the first flow path, which is at least a part of the wall portion of the nozzle body; Outer wall meat The thickness is The wall of the head portion faces the outer wall portion. Inner wall meat Thicker than thick.

[0008] In the above blast nozzle, Small At least a part of the curved surface portion that abuts against the extending direction of the first flow path may be coated with a hard coating. Small At least one ceramic chip is provided that is exposed on a part of the curved surface portion that abuts against the extension direction of the first flow path. The head portion may have a tip mounting hole that penetrates between the outside and the curved surface portion so as to be open to the outside in the direction opposite to the opening direction of the injection port, and that allows a tip to be attached and detached freely. the nozzle body includes a third flow path that is parallel to at least a portion of the first flow path and through which compressed air flows, an upstream end of the third flow path that is open to the outside from an outer circumferential surface of the nozzle body, A connecting pipe section for connecting a supply hose for supplying compressed air from the outside, The downstream end of the third flow path is The compressed air is directed toward the nozzle along the curved surface of the outer wall. Open to the second flow path It may also be an air inlet. The nozzle body and the head portion may be made of metal. Alternatively, the nozzle body and the head portion may be made of ceramic. The nozzle body and the head portion may be integrally molded by three-dimensional additive manufacturing. Furthermore, the nozzle body and the head portion may be made of the same material as the workpiece onto which the blasting media is sprayed. [Effects of the Invention]

[0009] According to the present disclosure, it is possible to provide a blast nozzle that can easily perform blast processing on a work surface located in a narrowed section while suppressing a decrease in service life. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a side view of a blast gun including a blast nozzle according to a first embodiment. FIG. [Figure 2] FIG. 1 is a perspective view of a blast nozzle according to a first embodiment. [Figure 3] FIG. 2 is a cross-sectional view of the blast nozzle according to the first embodiment. [Figure 4] FIG. 10 is a cross-sectional view of a blast nozzle according to a second embodiment. [Figure 5] FIG. 10 is a first perspective view of a blast nozzle according to a third embodiment. [Figure 6] FIG. 10 is a second perspective view of the blast nozzle according to the third embodiment. [Figure 7] FIG. 10 is a cross-sectional view of a blast nozzle according to a third embodiment. [Figure 8] FIG. 10 is a perspective view of a blast nozzle according to a fourth embodiment. [Figure 9]FIG. 10 is a cross-sectional view of a blast nozzle according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, several exemplary embodiments will be described with reference to the drawings. Hereinafter, the dimensions, materials, and other specific numerical values ​​shown in each embodiment are merely examples and do not limit the present disclosure unless otherwise specified. Furthermore, elements having substantially the same functions and configurations are assigned the same reference numerals to avoid redundant explanation, and elements not directly related to the present disclosure are not shown.

[0012] (First embodiment) FIG. 1 is a side view of a blast gun 1 including a blast nozzle 10 according to a first embodiment. The blast gun 1 is provided in a blasting device that performs blast processing on a workpiece 100 and sprays blast media BM, such as abrasive grains, onto the workpiece 100 using compressed air CA. The blast gun 1 includes a blast gun main body 2 and a blast nozzle 10 that is removably connected to the blast gun main body 2. The blasting device that employs the blast gun 1 may be either a direct pressure type or a suction type. The blast gun main body 2 may be a type used in a general blasting device, and therefore a detailed description thereof will be omitted below. The components of the blasting device other than the blast gun 1 may also be a type used in a general blasting device, and therefore will not be illustrated or described in detail.

[0013] FIG. 1 illustrates, as an example, a cross section of a workpiece 100 having a narrowed portion 101. The narrowed portion 101 includes an opening 101a facing the outside of the workpiece 100, forming a narrow spatial region within the workpiece 100. In this embodiment, the target portion to which the blasting media BM is sprayed is a workpiece surface 101b located in a portion of the narrowed portion 101. During blasting, an operator holds the blast gun 1 in one hand and inserts the blast nozzle 10 into the narrowed portion 101 so that the nozzle 12a faces the workpiece surface 101b. The operator then operates the blasting device to spray the blasting media BM from the nozzle 12a. Alternatively, the blast gun 1 may be held by, for example, a robot equipped with multiple movable arms, which automatically moves and sprays the blasting media BM.

[0014] Fig. 2 is a perspective view of the blast nozzle 10 as seen from a position where the injection port 12a can be seen. Fig. 3 is a cross-sectional view of the blast nozzle 10. The cross section in Fig. 3 is along a plane including the extension direction (axial direction) of each of the first flow path 11b and the second flow path 12b described below. The blast nozzle 10 has a nozzle body 11 and a head portion 12.

[0015] The nozzle body 11 has a straight pipe shape with a linearly extending internal space as the first flow path 11b. The first flow path 11b circulates the blasting media BM accompanied by compressed air CA introduced from the blast gun body 2 through the inlet 11a. Hereinafter, the direction in which the first flow path 11b extends is defined as the extension direction D1. The length of the first flow path 11b is defined as the flow path length L1. The cross section of the first flow path 11b is a circle defined by the flow path diameter d1.

[0016] Here, the ratio (L1 / d1) of the flow path length L1 to the flow path diameter d1 may be in the range of 5 to 50. For example, if the flow path diameter d1 is 10 mm, the flow path length L1 can be set to 50 mm (L1 / d1=5), or the flow path length L1 can be set to 100 mm (L1 / d1=10). This ratio range makes it possible to ensure the overall length of the blast nozzle 10 while maintaining the injection force of the blasting media BM sufficient to perform normal blasting.

[0017] Furthermore, the thickness T1a of the wall of the first flow path 11b is approximately constant along the extension direction D1. However, the nozzle body 11 may have a base portion 11c on the side connected to the blast gun body 2. In this case, the thickness T1b of the base portion 11c may be thicker than the thickness T1a. The specific shape of the base portion 11c is set to match the shape of the nozzle attachment port pre-installed in the blast gun body 2. The base portion 11c may have a tapered portion 11d therein that gradually narrows the flow path diameter from the inlet 11a to the flow path portion with a flow path diameter d1, in order to make it easier to guide the blast media BM from the blast gun body 2 to the first flow path 11b.

[0018] The head portion 12 is provided at the downstream tip of the nozzle body 11 and includes a second flow path 12b therein. One end of the second flow path 12b communicates with the downstream side of the first flow path 11b. The other end of the second flow path 12b is an ejection port 12a that ejects the blasting medium BM to the outside. The cross section of the second flow path 12b is a circular cross section defined by a flow path diameter d2. In this embodiment, the flow path diameter d2 is approximately the same as the flow path diameter d1 of the first flow path 11b. The head portion 12 also has a curved portion 12c therein that makes at least a portion of the second flow path 12b a curved flow path so that the opening direction D2 of the ejection port 12a is different from the extension direction D1 of the first flow path 11b.

[0019] Here, the thickness of at least a portion of the wall of the head portion 12 is thicker than the thickness of at least a portion of the wall of the nozzle body 11. For example, the comparison here is assumed to be the thickness T1a of the wall of the nozzle body 11. In contrast, at least a portion of the wall of the head portion 12 is assumed to be the outer wall portion 12d located outside the curved portion 12c. In this case, the thickness T2a of the outer wall portion 12d is thicker than the thickness T1a of the wall of the nozzle body 11. In other words, at least a portion of the head portion 12 has a stronger structure than the nozzle body 11.

[0020] 2 and 3, the angle θ formed by the opening direction D2 of the ejection port 12a with respect to the extension direction D1 of the first flow path 11b is set to approximately 45°. However, in this embodiment, the angle θ is not limited to such an angle value and may be set to an angle value in the range of 1° to 135°. In other words, the angle θ may be appropriately set based on the shape of the narrowed portion 101 to an angle that makes it easy for the blast nozzle 10 to enter through the opening 101a and makes it easy for the blasting media BM ejected from the ejection port 12a to reach the workpiece surface 101b.

[0021] Furthermore, when the nozzle body 11 has a base portion 11c, the maximum cross-section of the head portion 12 is smaller than the maximum cross-section of the base portion 11c when compared in a plane perpendicular to the extension direction D1 of the first flow path 11b. For example, the maximum cross-section of the base portion 11c on a plane perpendicular to the extension direction D1 is a circular cross-section defined by the maximum outer diameter d3 (see FIG. 3). In this case, the maximum cross-section of the head portion 12 on a plane perpendicular to the extension direction D1 fits within the circular area defined by the maximum outer diameter d3. In other words, the outer shape of the head portion 12 is compact and does not protrude significantly in a direction different from other parts constituting the blast nozzle 10. Therefore, even when the opening shape of the opening 101a of the narrowed portion 101 is relatively small or the internal shape of the narrowed portion 101 is relatively complex, the blast nozzle 10 entering the narrowed portion 101 is unlikely to interfere with the surface forming the narrowed portion 101.

[0022] Next, the operation and effect of the blast nozzle 10 will be described.

[0023] As shown in FIG. 1, the blast nozzle 10 connected to the blast gun body 2 has a nozzle body 11 including a first flow path 11b through which the blasting medium BM introduced from the blast gun body 2 flows (see FIG. 3). The blast nozzle 10 also has a head portion 12 provided at the downstream tip of the nozzle body 11 and including a second flow path 12b, one end of which communicates with the downstream side of the first flow path 11b and the other end of which is an ejection port 12a for ejecting the blasting medium BM to the outside. The nozzle body 11 has a straight pipe shape with the first flow path 11b being an internal space that extends linearly. The head portion 12 has a curved surface portion 12c inside, which makes at least a portion of the second flow path 12b a curved flow path so that the opening direction D2 of the ejection port 12a is different from the extension direction D1 of the first flow path 11b. Furthermore, the thickness of at least a portion of the wall of the head portion 12 (for example, thickness T2a) is greater than the thickness of at least a portion of the wall of the nozzle body 11 (for example, thickness T1a).

[0024] First, in the blast nozzle 10, the nozzle body 11 has a straight pipe shape. The head portion 12 is provided at the downstream tip of the nozzle body 11. Therefore, as shown in FIG. 1, even if the workpiece surface 101b is in a narrowed portion 101 of the workpiece 100, the blast nozzle 10 as a whole is less likely to interfere with the surface on which the narrowed portion 101 is formed, and is more likely to penetrate into the narrowed portion 101. Furthermore, the head portion 12 having the injection port 12a can more easily reach a desired position near the workpiece surface 101b.

[0025] The head portion 12 also includes a second flow path 12b, at least a portion of which is a curved flow path, and the opening direction D2 of the injection port 12a is different from the extending direction D1 of the first flow path 11b. Therefore, even if the workpiece surface 101b is located in a particularly complicated part of the narrowed portion 101, it is easy to face the injection port 12a to the workpiece surface 101b, and as a result, it is easy to perform blast processing on the workpiece surface 101b.

[0026] Furthermore, in general, in blast nozzles that use compressed air to deliver blast media, if there is a curved surface in the flow path leading to the nozzle, the curved surface may be damaged by the impact of the blast media, which is accelerated by the compressed air. In conventional curved nozzles or combinations of straight and curved nozzles, the wall thickness is generally uniform overall, making damage particularly likely to be caused by the blast media. In contrast, in the blast nozzle 10 according to the present embodiment, the head portion 12 has a curved surface 12c as part of the second flow path 12b, and at least a portion of the wall is thicker than at least a portion of the wall of the nozzle body 11. Therefore, at least a portion of the wall of the head portion 12 is structurally stronger than the other wall portions, thereby reducing damage. Furthermore, even if the curved surface 12c is worn due to the impact of the blast media BM, the thicker wall portion can extend the service life of the blast nozzle 10.

[0027] As described above, according to this embodiment, it is possible to provide a blast nozzle 10 that can easily perform blast processing on the surface 101b to be processed in the narrowed portion 101 while suppressing a decrease in the service life.

[0028] In the blast nozzle 10, the thickness T2a of the outer wall portion 12d of the curved surface portion 12c of the head portion 12 may be thicker than the thickness T2b of the inner wall portion 12e of the curved surface portion 12c.

[0029] Here, the blasting media BM that has flowed through the first flow path 11b of the nozzle body 11 is particularly likely to collide with the outer wall portion 12d, which is located on the extension of the extension direction D1 of the first flow path 11b, among the wall portions that constitute the curved surface portion 12c in the head portion 12. Therefore, with this blast nozzle 10, by setting the thickness T2a of the outer wall portion 12d to be thicker than the thickness T2b of the inner wall portion 12e, it is possible to particularly reinforce the portions that are prone to damage and wear.

[0030] In addition, in the blast nozzle 10, the nozzle body 11 and the head portion 12 may be made of metal.

[0031] Such a blast nozzle 10 can be manufactured at low cost.

[0032] On the other hand, in the blast nozzle 10, the nozzle body 11 and the head portion 12 may be made of ceramics.

[0033] Such a blast nozzle 10 can have improved wear resistance compared to a blast nozzle 10 made of metal.

[0034] In addition, in the blast nozzle 10, the nozzle body 11 and the head portion 12 may be integrally molded by three-dimensional additive manufacturing.

[0035] For example, when attempting to mass-produce the blast nozzle 10 at low cost, it is desirable to manufacture the blast nozzle 10 as a single unit, but due to the configuration or shape of the blast nozzle 10, it may be difficult to manufacture it using conventional cutting processes, etc. In contrast, such a blast nozzle 10 is molded as a single unit using a three-dimensional layered manufacturing device as an additive manufacturing device, which is advantageous in terms of cost reduction and mass production.

[0036] In this embodiment, the nozzle body 11 and the head portion 12 are integral with each other. However, if manufacturing permits, the blast nozzle 10 of the present disclosure may be manufactured by conventional cutting or the like. Alternatively, the nozzle body 11 and the head portion 12 may be manufactured separately in advance, and then joined together by welding or the like to manufacture the blast nozzle 10.

[0037] The nozzle body 11 and the head portion 12 may also be formed by three-dimensional metal additive manufacturing using metal powder. The metal powder used in this case may be any of various metal powders commonly used in three-dimensional metal additive manufacturing technology, and may be, for example, titanium (Ti)-based powder or nickel (Ni)-based powder.

[0038] Alternatively, the nozzle body 11 and the head portion 12 may be formed by three-dimensional additive manufacturing using ceramic powder. The ceramic powder used in this case may be any of various ceramic powders commonly used in three-dimensional additive manufacturing techniques, and may be, for example, alumina (Al2O3) ceramic powder.

[0039] Furthermore, in the blast nozzle 10, when the nozzle body 11 and the head portion 12 are integrally molded by three-dimensional additive manufacturing, the material of the nozzle body 11 and the head portion 12 may be the same as the material of the workpiece 100 onto which the blast media BM is sprayed.

[0040] For example, when the workpiece 100 is manufactured by three-dimensional metal additive manufacturing using titanium-based powder and then pre-sintered, the pre-sintered powder may adhere (remain) to the workpiece 100. In this case, the pre-sintered powder adhering to the workpiece 100 can be removed using a blast gun 1 equipped with a blast nozzle 10. Here, the blast media BM may be a titanium-based abrasive similar to the titanium, which is the material of the workpiece 100. The blast nozzle 10 used to remove the pre-sintered powder may also be manufactured by three-dimensional metal additive manufacturing using titanium-based powder similar to the titanium, which is the material of the workpiece 100. With such a blast nozzle 10, even if the curved surface 12c is worn due to the collision of the blast media BM, the powder that is scraped off from the curved surface 12c and sprayed onto the workpiece 100 with the flow of the blast media BM is of the same quality as the workpiece 100. Therefore, concerns about contamination, such as changes in the physical properties of the workpiece 100 after sintering due to the influence of different powders, can be avoided in advance.

[0041] Note that, when the blast nozzle 10 and the workpiece 100 are manufactured by three-dimensional metal additive manufacturing using metal powders of the same quality as in the above example, they may be manufactured simultaneously in a single manufacturing process. Such a blast nozzle 10 is manufactured in conjunction with the manufacturing process of the workpiece 100, which has the advantage of eliminating the manufacturing process for manufacturing only the blast nozzle 10 and preventing the inventory of more blast nozzles 10 than necessary.

[0042] (Second embodiment) 4 is a cross-sectional view of a blast nozzle 20 according to the second embodiment. The blast nozzle 20 differs from the blast nozzle 10 according to the first embodiment in that a hard coating 21 is applied to at least a portion of the curved surface portion 12c that abuts against the extension direction D1 of the first flow path 11b. Note that the components of the blast nozzle 20 other than the hard coating 21 are the same as the components of the blast nozzle 10 according to the first embodiment, and therefore are denoted by the same reference numerals and will not be described again.

[0043] Here, the blast nozzle 20 is formed by integrally molding the nozzle body 11 and the head portion 12 using three-dimensional metal additive manufacturing. In other words, from the viewpoint of the material used for manufacturing, the blast nozzle 20 has inferior wear resistance compared to a case where it is made of ceramic. Therefore, in this embodiment, a hardened coating 21 is applied to at least a portion of the curved surface portion 12c in the head portion 12. The hardened coating 21 may be any coating that improves the surface hardness (strength) of the curved surface portion 12c. For example, the hardened coating 21 may be a TiN (titanium nitride) film formed by PVD (physical vapor deposition) coating.

[0044] Furthermore, the blasting media BM passing through the first flow path 11b of the nozzle body 11 is particularly likely to collide with the outer wall portion 12d, which is located on the extension of the extension direction D1, among the wall portions constituting the curved portion 12c in the head portion 12. Therefore, it is desirable to apply the hardened coating 21 to the surface of the outer wall portion 12d of the curved portion 12c, as shown in Figure 4. However, the hardened coating 21 may also be applied to the entire wall portion of the curved portion 12c or the entire inner wall of the second flow path 12b.

[0045] This blast nozzle 20 achieves the same effects as the blast nozzle 10 according to the first embodiment. In particular, the blast nozzle 20 is manufactured by three-dimensional metal additive manufacturing, which reduces manufacturing costs, and the hardened coating 21 protects the portions of the second flow path 12b that are likely to be hit by the blast media BM, which is advantageous in terms of reducing a decrease in service life. Note that this hardened coating 21 is not necessarily applicable only to blast nozzles 20 manufactured by three-dimensional metal additive manufacturing, but can also be applied to blast nozzles manufactured by conventional cutting processes, for example, to improve wear resistance.

[0046] (Third embodiment) Fig. 5 is a perspective view of the blast nozzle 30 according to the third embodiment, seen from a position where the ejection port 32a can be seen. Fig. 6 is a perspective view of the blast nozzle 30, seen from a position where the opposite side of the ejection port 32a in the head portion 32 can be seen. Fig. 7 is a cross-sectional view of the blast nozzle 30. The cut surface in Fig. 7 is along a plane including the extension direction (axial direction) of each of the first flow path 31b and the second flow path 32b.

[0047] Like the blast nozzle 10 according to the first embodiment, the blast nozzle 30 has a nozzle body 31 and a head portion 32. The blast nozzle 30 differs from the blast nozzle 10 according to the first embodiment in that the head portion 32 has a ceramic tip 34 exposed at least in a part of the curved surface portion 32c against which the extension direction D1 of the first flow path 31b abuts.

[0048] The inlet 31a, first flow path 31b, and base 31c included in the nozzle body 31 correspond to the inlet 11a, first flow path 11b, and base 11c included in the nozzle body 11 of the first embodiment. Therefore, detailed description will be omitted below. The extension direction D1 of the first flow path 31b is also the same as the extension direction D1 described in the first embodiment.

[0049] Furthermore, the nozzle 32a, second flow path 32b, curved surface 32c, outer wall 32d, and inner wall 32e included in the head portion 32 correspond to the nozzle 12a, second flow path 12b, curved surface 12c, outer wall 12d, and inner wall 12e included in the head portion 12 of the first embodiment. Therefore, detailed description will be omitted below. The opening direction D2 of the nozzle 32a is also the same as the opening direction D2 described in the first embodiment.

[0050] Here, in the blast nozzle 30, the nozzle body 31 and the head portion 32 are integrally formed by three-dimensional metal additive manufacturing. In other words, in terms of the material used for manufacturing, the blast nozzle 30 has inferior wear resistance compared to a blast nozzle made of ceramic. Therefore, in this embodiment, the head portion 32 further has a tip mounting hole 32f in the outer wall portion 32d, and is equipped with a tip 34 that is attached to the tip mounting hole 32f.

[0051] Tip attachment hole 32f penetrates between the outside and curved surface portion 32c, allowing tip 34 to be attached and detached. One opening of tip attachment hole 32f is open to the outside from the side opposite jet nozzle 32a in head portion 32, and is the opening through which tip 34 is attached or detached. The other opening of tip attachment hole 32f is open from at least a part of curved surface portion 32c that abuts in extension direction D1 of first flow path 31b.

[0052] The head portion 32 may also have a threaded hole 32g that penetrates between the outside and the tip mounting hole 32f and is used to hold the tip 34 in the tip mounting hole 32f. In this case, the head portion 32 may also have a set screw 35 that engages with the threaded hole 32g. The set screw 35 may simply press the tip 34 inserted into the tip mounting hole 32f from one direction. Alternatively, as shown in FIG. 6, the set screw 35 may engage with an engagement hole 34a that is pre-formed in the tip 34. This configuration can prevent the tip 34 from falling out of the tip mounting hole 32f during blasting.

[0053] 7, when the chip 34 is attached to the chip attachment hole 32f, a part of the flat surface 34b of the chip 34 is exposed to at least a part of the curved surface portion 32c against which the extension direction D1 of the first flow path 31b abuts.

[0054] 6, part of the outer shape of the tip 34 may be matched to the outer shape of the head portion 32. When the tip 34 is attached to the head portion 32, it does not protrude outward from the outer peripheral surface of the head portion 32, so that it is possible to prevent the protruding part of the tip 34 from interfering with the workpiece 100 during blasting.

[0055] As described above, the blasting media BM passing through the first flow path 11b of the nozzle body 11 is particularly likely to collide with the outer wall portion 12d, which is located on an extension of the extension direction D1, among the wall portions constituting the curved surface portion 12c in the head portion 12. In contrast, in the blast nozzle 30, a portion of the tip 34 is exposed to a portion of the curved surface portion 32c with which the blasting media BM is likely to collide, i.e., the curved surface portion 32c formed by the outer wall portion 32d. Therefore, the blasting media BM passing through the first flow path 31b is more likely to collide with the flat surface 34b of the tip 34, which is a ceramic portion with higher wear resistance, than the metal portion formed by three-dimensional metal additive manufacturing.

[0056] Such a blast nozzle 30 provides the same effects as the blast nozzle 10 according to the first embodiment. In particular, the blast nozzle 30 can be manufactured by, for example, three-dimensional metal additive manufacturing, thereby reducing manufacturing costs, and the tip 34 protects the portions of the second flow path 32b that are likely to be hit by the blast media BM, which is advantageous in terms of preventing a decrease in service life.

[0057] Furthermore, if the tip 34 becomes significantly worn due to the collision of the blasting media BM, the worker can release the retention of the tip 34 by the retaining screw 35 and replace the used tip 34 with a new tip 34, thereby further extending the service life of the blasting nozzle 30.

[0058] (Fourth embodiment) Fig. 8 is a perspective view of the blast nozzle 40 according to the fourth embodiment, seen from a position where the ejection port 42a can be seen. Fig. 9 is a perspective view of the blast nozzle 40, seen from a position where the opposite side of the ejection port 42a in the head portion 42 can be seen. Fig. 9 is a cross-sectional view of the blast nozzle 40. The cut surface in Fig. 9 is along a plane including the extension directions (axial directions) of the first flow path 41b and the second flow path 42b.

[0059] Similar to the blast nozzle 10 according to the first embodiment, the blast nozzle 40 has a nozzle body 41 and a head portion 42. The blast nozzle 40 differs from the blast nozzle 10 according to the first embodiment in that compressed air CA is supplied from the curved surface portion 42c of the head portion 42 toward the second flow path 42b through a third flow path 41e different from the first flow path 41b of the nozzle body 41.

[0060] The inlet 41a, first flow path 41b, and base 41c included in the nozzle body 41 correspond to the inlet 11a, first flow path 11b, and base 11c included in the nozzle body 11 of the first embodiment. Therefore, detailed description will be omitted below. The extension direction D1 of the first flow path 41b is also the same as the extension direction D1 described in the first embodiment.

[0061] Furthermore, the nozzle 42a, second flow path 42b, curved surface 42c, outer wall 42d, and inner wall 42e included in the head portion 42 correspond to the nozzle 12a, second flow path 12b, curved surface 12c, outer wall 12d, and inner wall 12e included in the head portion 12 of the first embodiment. Therefore, detailed description will be omitted below. The opening direction D2 of the nozzle 42a is also the same as the opening direction D2 described in the first embodiment.

[0062] Here, in the blast nozzle 40, the nozzle body 41 and the head portion 42 are integrally formed by three-dimensional metal additive manufacturing. In other words, in terms of the material used for manufacturing, the blast nozzle 40 has inferior wear resistance compared to a case where it is made of ceramic. Therefore, in this embodiment, the nozzle body 41 further includes a third flow path 41e that is parallel to at least a portion of the first flow path 41b and through which compressed air CA flows.

[0063] First, the upstream end of the third flow path 41e opens to the outside from the outer circumferential surface of the nozzle body 41. In this embodiment, the nozzle body 41 has a connecting pipe portion 41f, which serves as the upstream end of the third flow path 41e, to which a supply hose for supplying compressed air CA from the outside is connected. The connecting pipe portion 41f may be shaped as a whole in the form of a so-called hose nipple. Furthermore, an internal flow path 41g of the connecting pipe portion 41f is continuous with the upstream side of the third flow path 41e.

[0064] Meanwhile, the downstream end of the third flow path 41e serves as an air inlet 41h, which opens from the curved surface portion 42c of the head portion 42 to the second flow path 42b in accordance with the opening direction D2 of the jet nozzle 42a. In other words, the jet nozzle 42a exists on an extension of the air inlet 41h.

[0065] Note that, because the third flow path 41e is a flow path through which compressed air CA flows, the flow path diameter of the third flow path 41e may be smaller than the flow path diameter of the first flow path 41b. Furthermore, the cross-sectional shape of the third flow path 41e does not necessarily have to be circular, and may be elliptical or the like. For example, if the cross-sectional shape of the first flow path 41b is circular, the cross-sectional shape of the third flow path 41e may be crescent-shaped and the third flow path 41e may be positioned so that the concave side of the crescent faces the first flow path 41b, thereby making the cross-sectional shape of the nozzle main body 41 more compact.

[0066] As described above, the blasting media BM passing through the first flow passage 11b of the nozzle body 11 is particularly likely to collide with the outer wall portion 12d, which is located on an extension of the extension direction D1, among the wall portions constituting the curved portion 12c in the head portion 12. In contrast, in the blast nozzle 40, compressed air CA is introduced from the air inlet 41h to a portion of the curved portion 42c with which the blasting media BM is likely to collide, i.e., the curved portion 42c formed by the outer wall portion 42d. The introduced compressed air CA flows toward the ejection port 42a in accordance with the opening direction D2 of the ejection port 42a, i.e., along the surface shape of the curved portion 42c. Therefore, the airflow containing the blasting media BM that has passed through the first flow passage 11b toward the portion of the curved portion 42c that abuts against the extension direction D1 of the first flow passage 31b is forcibly bent toward the ejection port 42a by the compressed air CA flowing in from the air inlet 41h. That is, the impact force when the blasting media BM hits the curved surface portion 42c is weaker than when the compressed air CA is not flowed in through the air inlet 41h, and as a result, wear on the curved surface portion 42c is suppressed.

[0067] Such a blast nozzle 40 provides the same effects as the blast nozzle 10 according to the first embodiment. In particular, the blast nozzle 40 is manufactured by, for example, three-dimensional metal additive manufacturing, which reduces manufacturing costs, and the action of the compressed air CA flowing in from the air inlet 41h reduces wear on the curved surface portion 42c, making it more advantageous in terms of preventing a decrease in service life.

[0068] Furthermore, even if the third flow path 41e is provided in the nozzle body 41, the shape of the third flow path 41e allows the cross-sectional shape of the nozzle body 41 to be made compact. Therefore, even if the workpiece surface 101b is in the narrowed portion 101 of the workpiece 100, the blast nozzle 40 can be made less likely to interfere with the workpiece 100.

[0069] Although several embodiments have been described, the embodiments can be modified or varied based on the above disclosure. All components of the above embodiments and all features described in the claims may be individually extracted and combined, unless they contradict each other. [Explanation of symbols]

[0070] 10, 20, 30, 40 Blast Nozzle 11, 31, 41 Nozzle body 11b, 31b, 41b First flow path 12, 32, 42 Head 12a,32a,42a Nozzle 12b, 32b, 42b Second flow path 12c,32c,42c curved part 12d,32d,42d Outer wall 12e,32e,42e Inner wall 21 Hard coating 32f Tip mounting hole 34 chips 41e Third Stream 41f Connection pipe section 41h Air inlet BM Blast Media D1: Extension direction of the first flow path D2 Orifice opening direction T1a Nozzle body wall thickness T2a: Thickness of outer wall of head T2b: Thickness of the inner wall of the head

Claims

1. A blast nozzle connected to a blast gun body, a nozzle body including a first flow path through which the blasting medium introduced from the blast gun body flows; a head portion including a second flow path provided at a downstream tip of the nozzle body, one end of which communicates with the downstream side of the first flow path and the other end of which is an ejection port for ejecting the blasting medium to the outside; The nozzle body and the head portion are integrally molded, the nozzle body has an internal space that extends linearly as the first flow path, and a portion that has a straight pipe shape in which a wall portion that forms the first flow path has a constant thickness, the head portion has a curved surface portion therein that makes at least a part of the second flow path a curved flow path so that an opening direction of the injection port is a direction different from an extension direction of the first flow path, a thickness of an outer wall portion constituting the curved surface portion, which is at least a part of a wall portion of the head portion and is located on an extension of the first flow path in the extension direction, that is thicker than a thickness of a wall portion forming the first flow path, which is at least a part of a wall portion of the nozzle body, A blast nozzle, wherein the thickness of the outer wall portion is greater than the thickness of an inner wall portion of the wall portion of the head portion that faces the outer wall portion.

2. The blast nozzle according to claim 1 , wherein at least a portion of the curved surface portion that abuts against the extending direction of the first flow path is coated with a hard coating.

3. a ceramic tip exposed at least in a part of the curved surface portion that abuts against the extension direction of the first flow path; 2. The blast nozzle according to claim 1, wherein the head portion has a tip mounting hole that penetrates between the outside and the curved portion so as to be open to the outside along a direction opposite to the opening direction of the injection port, and allows the tip to be attached and detached freely.

4. the nozzle body includes a third flow path that is parallel to at least a portion of the first flow path and through which compressed air flows; an upstream end of the third flow path is a connecting pipe portion that is open to the outside from an outer circumferential surface of the nozzle body and that connects a supply hose that supplies the compressed air from the outside; 2. The blast nozzle according to claim 1, wherein a downstream end of the third flow path is an air inlet that opens to the second flow path so that the introduced compressed air is directed toward the jet port along a surface shape of the curved portion of the outer wall portion.

5. The blast nozzle according to any one of claims 1 to 4, wherein the nozzle body and the head portion are made of a metal.

6. The blast nozzle according to any one of claims 1 to 4, wherein the nozzle body and the head portion are made of ceramics.

7. The blast nozzle according to any one of claims 1 to 6, wherein the nozzle body and the head portion are integrally molded by three-dimensional additive manufacturing.

8. The blast nozzle according to claim 7 , wherein the nozzle body and the head portion are made of the same material as the workpiece onto which the blasting medium is sprayed.

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