Nozzle

Abstract: A nozzle (20) which has a cylindrical nozzle main body (21). A nozzle tip (22) comprises a plurality of members formed by dividing an approximately cylindrical member in the axial direction thereof and is accommodated in the interior of the nozzle main body (21). A spring (23) is provided between a spring receiving section (34) of the nozzle tip and a wall positioned on a forward side of the nozzle main body (21). At least one of a peripheral surface of a discharge section (33) of the nozzle tip and an inner surface of a tip engaging opening (27) of the nozzle main body (21) is tapered. When a self-cleaning operation is performed with an atomization pressure reduced, the spring (23) urges the nozzle tip (22) toward a backward side of the nozzle main body (21).

Description: The present invention relates to a nozzle and more particularly, to a nozzle having a self-cleaning operation of automatically discharging foreign matter which has collected in a fluid path of the nozzle. The nozzle is preferably used to clean a paper making machine because many solid bodies penetrate in liquid or fluid used for cleaning. The nozzle is also used as an acid wash nozzle for an iron manufacturing machine. Description of the Related art Conventionally, there is proposed a self-cleaning nozzle of this kind as shown in Fig. 28 which automatically discharges foreign matter which has collected in the interior thereof by reducing atomization pressure during a self-cleaning operation. According to the above-described self-cleaning nozzle, a spray button 3 having a groove 2 formed thereon is fixed to the leading end portion of a nozzle main body 1, a piston 5 slidably provided in the main body 1 is urged by a spring 4 in the direction opposite to the spray button 3, and the end portion of the piston 5 opposite to the spray button 3 is sealed with a diaphragm 6 having flexibility. In atomizing operation, the piston 5 is pressed against the spray button 3 against the resilience of the spring 4 by the atomization pressure of liquid or fluid which has been introduced into the nozzle in the direction shown by an arrow (A) (axial direction of nozzle) of Fig. 29 and an injection opening 7 consisting of a slit-shaped orifice is formed by the groove 2 and the leading end of the piston 5 so as to spray liquid or fluid in the direction shown by the arrow (B) approximately perpendicular to the direction shown by the arrow (A). If foreign matter has collected in the above nozzle and liquid or fluid is prevented from flowing, the atomization pressure is reduced so that the piston 5 is moved backward or to the original position by the spring 4 so as to return the state of the nozzle to the original state as shown in Fig. 28. Thus, the injection opening 7 is opened and as a result, the foreign matter is discharged. However, according to the above self-cleaning nozzle 11, the injection opening 7 consists of a thin slit-shaped orifice, i.e., the diameter of the path for flowing liquid or fluid is small. Therefore, compared with other fan-shaped nozzles, foreign matter is likely to collect in the injection opening 7 when a spray operation is performed. According to the nozzle 11, the liquid introducing direction (direction shown by the arrow (A)) is approximately perpendicular to the atomization direction (direction shown by the arrow (B)). When the nozzle 11 is used by mounting it on a pipe 10 as shown in Fig. 30, the following problems occur: That is, when the injection opening 7 mounted on the pipe 10 looks down vertically as shown in Figs. 31 and 32, the atomization distribution 12 and the atomization region 13 are symmetrical with respect to the nozzle 11 as shown in Fig. 33. But when the injection opening 7 does not look down vertically as shown in Figs. 34 and 35, the atomization region 13 is dislocated as shown in Fig. 36 and the atomization distribution 12 is not bisymmetrical with respect to the nozzle 12. In addition, when a plurality of the nozzles 11 are mounted on the pipe 10 with regular intervals spaced from each other to spray liquid to cover a long distance as shown in Fig. 37, atomization patterns 14 of the adjacent nozzles 11 overlap with each other, with the result that atomized liquid interfere with each other as denoted by reference symbol 15. Since the atomization distribution 12 and the atomization region 13 are not bisymmetrical with respect to the nozzle 12 and the interference 15 of the atomization pattern is likely to occur, it is necessary that the nozzle 11 is positioned accurately. Therefore, as shown in Fig. 30, a parallel thread 16 is provided on the periphery of the nozzle 11 so as to mount the nozzle 11 on the pipe 10 by tightening the parallel screw 16 into a screw mounted on the surface 10a of the pipe 10. The mounting mechanism requires a lock nut 17 for an accurate positioning and an O-ring 18 for preventing a liquid leakage. Further, it is necessary to flatten the mounting surface 10a by flattening the nozzle mounting position of the pipe 10. As described above, according to the conventional nozzle, the number of parts and piping processes increases and moreover, labor for mounting parts on the pipe increases. GB-A-987 723 discloses a nozzle according to the pre-characterizing portion of claim 1. In this construction, every time liquid flow ceases the segments of the orifice forming member are pulled back and thereby prevent any substances in the liquid to collect in or upon the surface of the jet orifice. Nevertheless, this nozzle has a drawback in that it can only operate if it is mounted up-ride so that the crovitation pulls back the segments. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a nozzle which prevents foreign matter from collecting in a fluid path and reliably discharges it owing to the drop of atomization pressure while a self-cleaning operation is performed if the foreign matter collects therein by providing a large diameter fluid path communicating with an injection opening. It is another object of the present invention to provide a nozzle which prevents fluid from being atomized non-bisymmetrically with respect to the nozzle by making the direction in which the nozzle is mounted on a fluid supplying pipe coincide with the atomization direction of the nozzle irrespective of the nozzle mounting direction and which prevents fluid atomized from a plurality of nozzles from interfering with each other when the nozzles are mounted on the pipe with intervals provided therebetween. It is still another object of the present invention to provide a nozzle which eliminates the use of a lock nut for placing the nozzle in position and an O-ring for preventing a fluid leakage and the process for flattening the nozzle mounting surface and which reduces the number of parts, processes, and installing operations. In accomplishing these and other objects, there is provided a nozzle according to the present invention comprising: a nozzle main body which is cylindrical and has a fluid inlet provided on the backward side thereof and a tip engaging opening provided on the forward side thereof; a nozzle tip comprising: a plurality of members formed by dividing an approximately cylindrical member in the axial direction thereof; and a discharge section having an injection opening in the forward end of said cylindrical member; said nozzle tip being accomodated in the interior of said nozzle main body with said discharge section slidably engaging said tip engaging opening so that fluid flowing from a fluid inlet is atomized from said injection opening through a fluid path extending along the axis of said nozzle main body; and wherein at least one of the peripherial surface of said discharge section of said nozzle tip and the inner peripheral surface of said tip engaging opening of said nozzle main body is tapered; and a part of said discharge section of said nozzle tip is engaged by a part of said tip engaging opening during an atomisation operation and during the self-cleaning operation in which said nozzle tip moves backward and said members of said nozzle tip move away from each other so as to discharge foreign matter which has penetrated into said fluid path, characterized by a spring receiving section projecting from the periphery of the backward side of said nozzle tip; and by a spring, provided between the spring receiving section of said nozzle tip and the wall positioned on the forward side of said nozzle main body, for urging said nozzle tip toward the backward side when a self-cleaning operations is performed with the atomization pressure reduced. In the above construction, at least one of the peripheral surface of the discharge section of the nozzle tip and the inner peripheral surface of the tip engaging opening of the nozzle main body is tapered; and a part of the discharge section of the nozzle tip is engaged by a part of the tip engaging opening during an atomization operation and during the self-cleaning operation in which the nozzle tip moves backward and the members of the nozzle tip move away from each other so as to discharge foreign matter which has penetrated into the fluid path. The nozzle tip is axially divided into a plurality of members such that each member includes fluid paths. According to another preferred embodiment, the axis of the nozzle main body coincides with the axis of the fluid path and the injection opening both extending along the axis of the approximately cylindrical nozzle tip accommodated in the interior of the nozzle main body; and a thread for mounting the nozzle main body on a fluid supply pipe is formed in the periphery of the nozzle main body in such a manner that the thread is positioned on the backward side of the nozzle main body and the axis of the thread coincides with that of the nozzle main body. According to still another preferred embodiment, the periphery of the discharge section of the spring receiving section is tapered to forcibly open the discharge section when the nozzle tip is moved backward by the resilience of the spring during the self-cleaning operation. Preferably, the thread-formed portion of the nozzle main is tapered. More specifically, the nozzle tip comprises two members formed by dividing an approximately cylindrical member in the axial direction thereof. On the discharge section side of the spring receiving section, the semispherical section of the pair of the members is tapered from the periphery thereof to the flat section as an inclined surface which forms a certain angle with the flat surface. Preferably, the peripheral surface of the discharge side and the inner peripheral surface of the tip engaging opening are tapered so that the forward end of the discharge side projects from the nozzle main body when an atomizing operation or a self-cleaning operation is performed. It is preferable to form a spring inserting opening in the spring receiving section and the nozzle main body so that each end of the spring is nonrotatable and elastic. A sectionally U-shaped groove is formed in the opening of the nozzle main body into which the retaining ring consisting of an elastic material is inserted so that the nozzle tip urged to move backward by the spring is prevented from falling off the nozzle main body. Preferably, a sectionally U-shaped packing mounting section is provided on the forward side of the spring receiving section so that a packing mounted around the packing mounting section seals the periphery of the nozzle tip. According to the nozzle of the above construction, the atomization pressure of fluid which has been introduced from the fluid inlet is greater than the resilience of the spring. Therefore, the discharge section projects from the tip engaging opening and fluid is sprayed from the injection opening in the axial direction of the nozzle. Upon reduction of the atomization pressure when foreign matter has collected in the fluid path of the nozzle tip, the nozzle tip consisting of a plurality of members move away from each other from the discharge section by the fluid pressure in the fluid path while the nozzle tip is moving backward by the spring. As a result, the foreign matter is discharged outside from the opened injection opening via the nozzle opening. The nozzle tip consisting of a plurality of members smoothly move away from each other from the discharge section by inclining the spring receiving surface from the periphery to the center thereof. The nozzle tip can be prevented from rotating with respect to the nozzle main body by inserting each end of the spring into the nozzle main body and the spring inserting opening of the spring surface. Since the axis of the nozzle main body coincides with the axis of the fluid path and the injection opening and the thread is formed on the periphery of the nozzle main body with the axis of the thread coinciding with that of the above axes, the axial direction of the thread and the injection direction of fluid coincide with each other. Even though the nozzle is not placed accurately on the pipe on the pipe, the fluid atomizing performance is not greatly affected. BRIEF DESCRIPTION OF THE INVENTION These and other objects and features of the present invention will become apparent from the following description taken in conjunction with preferred embodiments thereof with reference to the accompanying drawings, throughout which like parts are designated by like reference numerals, and in which: Fig. 1 is a sectional view showing a nozzle according to a first embodiment of the present invention; Fig. 2 is a plan view showing the nozzle shown in Fig. 1; Fig. 3 is a sectional view showing the nozzle shown in Fig. 1 which is performing a self-cleaning; Fig. 4 is a front view showing a member of a nozzle tip; Fig. 5 is a rear elevation showing the member of the nozzle tip shown in Fig. 4; Fig. 6 is a side elevation viewed from the right side of the member of the nozzle tip shown in Fig. 4; Fig. 7 is a perspective view showing the nozzle tip; Fig. 8 is a sectional view showing the condition in which foreign matter has penetrated into the nozzle; Fig. 9 is a sectional view showing the condition in which the nozzle of Fig. 1 is mounted on a pipe; Fig. 10 is a bottom view showing the condition in which the nozzle of Fig. 1 is mounted on the pipe at a predetermined angle; Fig. 11 is a schematic view showing the atomization distribution, atomization region, and atomization pattern obtained by the nozzle when it is mounted on the pipe as shown in Fig. 10; Fig. 12 is a schematic bottom view showing the condition in which a plurality of nozzles of Fig. 1 are mounted on the pipe; Fig. 13 is a schematic view showing the atomization condition in which the nozzle of Fig. 1 is mounted on the pipe as shown in Fig. 12; Fig. 14 is a sectional view showing a nozzle according to a second embodiment of the present invention; Fig. 15 is a plan view showing the nozzle of Fig. 14; Fig. 16 is a sectional view showing the nozzle of Fig. 14 performing a self-cleaning operation; Fig. 17 is a sectional view showing a nozzle according to a third embodiment of the present invention; Fig. 18 is a plan view showing the nozzle of Fig. 17; Fig. 19 is a sectional view showing the nozzle of Fig. 17 performing a self-cleaning operation; Figs. 20 and 27 are schematic sectional views showing modifications of the present invention; Figs. 28 and 29 are sectional views showing conventional nozzles; Fig. 30 is a sectional view showing the nozzle of Fig. 28 mounted on a pipe; Figs. 31 and 32 are schematic views showing the condition in which the injection opening of the nozzle of Fig. 28 looks down vertically; Fig. 33 is a schematic view showing atomization distribution and atomization region when the nozzle is mounted on a pipe as shown in Fig. 31; Figs. 34 and 35 are schematic views showing the condition in which the nozzle of Fig. 28 is mounted on the pipe with the injection opening of the nozzle inclined; Fig. 36 is a schematic view showing atomization distribution and atomization region when the nozzle is mounted on the pipe as shown in Fig. 32; and Fig. 37 is a schematic view showing the condition in which a plurality of nozzles of Fig. 28 mounted on the pipe performs an atomizing operation. DETAILED DESCRIPTION OF THE INVENTION Before the description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout the accompanying drawings. Referring to Figs. 1 through 3, a self-cleaning nozzle 20 according to a first embodiment of the present invention comprises a nozzle main body 21, a nozzle tip 22, a spring 23, a packing 24, and a retaining ring 25. The nozzle main body 21 is cylindrical with its forward end serving as the closed section 21a and its other end serving as a fluid inlet 21b. The inner diameter of the interior 21c of the nozzle main body 21 is uniform along an axis ℓ₂. The interior 21c accommodates the nozzle tip 22 and the spring 23. There is provided, in the center of the closed section 21a positioned on the forward end side of the nozzle main body 21, a tip engaging opening 27 tapered from the interior 21c of the main body 21 toward the exterior thereof. The cone angle ϑ₁ of the opening 27 and the diameter d₁ of the opening 27 on the forward end side of the nozzle main body 21 are set in correspondence with the cone angle ϑ₂ of the discharge section 33 of the nozzle tip 22 and its diameter d₂ on the forward end side thereof which will be described later. Thus, the discharge section 33 can be fixedly inserted into the opening section 27 such that the discharge section 33 projects from the opening 27. The interior 21c of the closed section 21a serves as a spring carrying section 28 in which one end of the spring 23 is retained. A spring inserting opening (not shown) is formed in the spring carrying section 28 so that one end of the spring 23 is fixedly inserted into the spring inserting opening. The periphery of the nozzle main body 21 is tapered on the fluid inlet 21b side thereof and a tapered thread 26 is formed thereon. A nut section 29 consisting of a hexagon nut is formed on the nozzle main body 21 such that the nut section 21 is positioned on the closed section 21a side of the nozzle main body 21. A sectionally U-shaped groove 30 for accommodating the retaining ring 25 is formed on the nozzle main body 21 such that the groove 30 is positioned on the fluid inlet 21b side of the nozzle main body 21. The approximately cylindrical nozzle tip 22 comprises a pair of semicylindrical members 31A and 31B in contact with each other as shown in Figs. 4 through 7. The forward end of the cylindrical section 32 of the nozzle tip 22 is tapered, thus serving as the discharge section 33 and the cone angle thereof is ϑ. A cylindrical spring receiving section 34 is formed in the periphery of the backward end of the cylindrical section 32. As shown in Fig. 5, in the nozzle tip 22, a first semispherical groove 35 and a second semispherical groove 36 which is smaller than the first semispherical groove 35 are formed on a flat section 40 of the pair of members 31A and 31B in contact with each other. As shown in Fig. 1, in the interior of the cylindrical section 32 of the nozzle tip 22, a first fluid path 37 and a second fluid path 38 smaller than the first fluid path 37 in diameter are continuously formed from the backward end of the nozzle main body 21 to the forward end of the discharge section 33 when the pair of members 31A and 31B are brought in contact with each other. That is, the nozzle tip 22 of the first embodiment is divided into the members 31A and 31B along the axis of the nozzle tip 22 so that each member 31A and 31B includes both the first and second fluid paths 37 and 38. In the discharge section 33, as shown in Figs. 6 and 7, when the pair of the members 31A and 31B are brought in contact with each other, a notch 41 is formed in the forward end portion of the flat surface 40 of the members 31A and 31B so as to form a V-shaped injection opening 42 in which the depth is (t) and the cone angle is ϑ₃ with ℓ₂ being the center line. On the discharge section 33 side of the spring receiving section 34, as shown in Fig. 6, the semispherical section 44 of the pair of the members 31A and 31B is tapered from the periphery thereof to the flat section 40 as an inclined surface 46 which forms an angle of ϑ₄ with the flat surface 40. Therefore, on the discharge section 33 side of the spring receiving section 34, a sectionally V-shaped spring receiving surface 47 is formed when the pair of the members 31A and 31B are brought in contact with each other. A spring inserting opening 46a for inserting one end of the spring 23 thereinto is provided on the inclined surface 46 of either the member 31A or the member 31B (the member 31B in this embodiment). A sectionally U-shaped packing mounting section 55 is provided below the spring receiving section 34. An annular packing 24 is mounted around the packing mounting section 55 so that the periphery of the nozzle tip 22 is sealed by the packing 24. Thus, fluid flows into the first fluid path 37 of the nozzle tip 22 via the fluid inlet 21b of the nozzle main body 21. The spring 23 and the nozzle tip 22 are accommodated in the interior 21c of the nozzle main body 21. The spring 24 is interposed between the spring carrying section 28 of the nozzle main body 21 and the spring receiving surface 47 of the nozzle tip 22. As described previously, since each end of the spring 23 is inserted into the spring fixing opening (not shown) of the spring carrying section 28 and the spring fixing opening 46a of the spring receiving surface 47, the spring 23 is incapable of rotating. Therefore, the nozzle tip 22 does not rotate in the nozzle main body 21, thus maintaining the same angular position, namely, the atomizing direction. The retaining ring 25 consisting of an elastic material is inserted into the groove 30 of the nozzle main body 21. The retaining ring 25 locks the spring receiving section 34 of the nozzle tip 22, thus preventing the nozzle tip 22 urged to move backward by the spring 23 from falling off the fluid inlet 21b of the nozzle main body 21. The operation of the self-cleaning nozzle 20 of the above construction is described below. In atomizing operation, fluid is introduced from the fluid inlet 21b of the nozzle main body 21 to the first fluid path 37 and the second fluid path 38 of the nozzle tip 22 in the direction shown by the arrow (C) of Fig. 1 (the axis ℓ₂ of the nozzle 20). As a result, the nozzle tip 22 is pressed toward the direction shown by the arrow (C) of Fig. 1 against the urging force of the spring 23. Consequently, the discharge section 33 of the nozzle tip 22 is inserted into the opening 27 of the nozzle main body 21 in such a condition that the forward end of the nozzle tip 22 projects from the tapered opening 27 as shown in Fig. 1. Thus, fluid is atomized in the direction coinciding with the axis ℓ₂ of the nozzle 20, namely, the axial direction of the tapered thread 26. As described previously, since the injection opening 42 is V-shaped with the cone angle thereof being ϑ₃ and the depth thereof being (t), the atomization pattern is similar to the configuration of the injection opening 42 as shown by the two-dot chain line of Fig. 2. As shown in Fig. 8, the nozzle 20 has the following self-cleaning operation if, as shown in Fig. 8, the atomizing performance is degraded, i.e., if the flow of the fluid is prevented as a result of the penetration of foreign matter into the first fluid path 37 or the second fluid path 38 and consequently, the foreign matter collects in the first fluid path 37 or the second fluid path 38. That is, the atomization pressure is reduced below the resilience of the spring 23. As a result, the nozzle tip 22 is moved backward, or toward the fluid inlet 21b by the spring 23 and as shown in Fig. 3, the pair of the members 31A and 31B is separated from each other from the discharge section 33 by the fluid pressure existing in the fluid paths 37 and 38 while the discharge section 33 is moving toward the fluid inlet 21b. At this time, the backward side of the nozzle tip 22 is locked by the retaining ring 25, and the forward end of the pair of the members 31A and 31B is fixedly inserted into the opening 27. Therefore, the foreign matter 57 which has collected in the fluid paths 37 and 38 flows outside from the opened discharge section 33 via the opening 27 of the nozzle main body 21. As described previously, according to the first embodiment, since the upper surface of the spring receiving surface 47 of the spring receiving section 34 makes a certain angle with the flat section 40 or sectionally V-shaped, the members 31A and 31B moves away from each other from the forward end thereof by the urging force of the spring 23 as shown in Fig. 3. As a result, the injection opening 42 is opened, thereby reliably discharging the foreign matter 57 outside. Upon increase of the atomization pressure after the foreign matter 57 is discharged outside, the nozzle tip 22 is pressed by the pressure again in the direction shown by the arrow (C). As described previously, since one end of the discharge section 33 is fixedly inserted into the opening 27, the nozzle tip 22 slides along the inner peripheral surface of the tapered opening 27, thus projecting from the tapered opening 27, with the result that the pair of the members 31A and 31B are brought into contact with each other and the nozzle 20 returns to the original state as shown in Fig. 1. Thus, the atomising operation is resumed. Since the foreign matter 57 is discharged outside, the nozzle 20 is capable of continuing the atomising operation without degrading the atomizing performance by repeating the above-described self-cleaning operation as necessary or periodically. The operation of the nozzle 20 which is described below relates to the use of the nozzle 20 by mounting a plurality of the nozzles 20 on a long fluid supplying pipe by spacing them from each other at a certain interval. In order to mount the nozzle 20 on a pipe 60, as shown in Fig. 9, the tapered thread 26 provided in the periphery of the nozzle main body 21 is tightened into a tapered thread opening 60a formed on the pipe 60. Since the nozzle 20 is mounted on the pipe 60 with the tapered thread 26, it is unnecessary to use an O-ring to prevent a fluid leakage. As shown by a solid line in Fig. 10, when the nozzle 20 is mounted on the pipe 60 so that the axis ℓ₃ of the pipe 60 coincides with the center line ℓ₁ of the fan-shaped injection opening 42 in the longitudinal direction thereof, the atomization distribution 65 and the atomization region 67 are bisymmetrical with respect to the nozzle 20 as shown in Fig. 11. As described previously, according to the first embodiment, fluid is atomized from the nozzle 20 in the direction coinciding with the axis ℓ₂ (the axis of mounting thread 26) thereof. Therefore, when the nozzle 20 makes an angle of, for example, ϑ₅ = 45° with the axis of the pipe 60 as shown in Fig. 10, the atomization pattern 66' makes an angle of ϑ₅ = 45° with the atomization pattern 66 of the above case, and the atomization distribution 65' is also bisymmetrical with respect to the nozzle 20 as shown in Fig. 11, and the atomization region 67' does not change greatly compared with the above-described case. That is, according to the first embodiment, it is unnecessary to mount the nozzle 20 with a high positioning accuracy or the use of a lock nut is not required. When a plurality of the nozzles 20 is mounted on the pipe 60 so that each nozzle 20 makes an angle of ϑ₆ with the axis ℓ₃ of the pipe 60 as shown in Fig. 12, the minor axes of approximate elliptical atomization patterns 66 are adjacent to each other as shown in Fig. 13. Thus, fluid atomized from each nozzle 20 does not interfere with each other. A second embodiment of the present invention is described below with reference to Fig. 14 through 16. A notch is not formed in the forward end of the discharge section 33, i.e., no members are provided between the injection opening 42 and the second fluid path 38. Therefore, the atomization pattern of the second embodiment is circular as shown by a two-dot chain line in Fig. 15 and fluid is atomized in the form of a circular bar. A third embodiment of the present invention is described below with reference to Fig. 17 through 19. Similarly to the second embodiment, a notch is not formed in the forward end of the discharge section 33, i.e., no members are provided between the injection opening 42 and the second fluid path 38. But in the discharge section 33, a pair of inclined walls 68 narrowed forward, or in the atomization direction is formed. Therefore, the atomization pattern of the third embodiment is as shown by a two-dot chain line in Fig. 18. The construction of other sections and operation of the second and third embodiments are similar to those of the first embodiment. Therefore, descriptions thereof are omitted. Various modifications of the present invention are apparent from the above description. For example, the nozzle tip 22 consists of a pair of members 31A and 31B in the above embodiments, but may consist of three members provided that the nozzle tip 22 is axially divided. Further, the opening 27 and the nozzle tip 22 provided in the closed section 21a of the nozzle main body 21 are both tapered in the above embodiments, but either the opening 27 or the nozzle tip 22 may tapered. That is, the discharge section 33 is tapered and the opening 27 is straight as shown in Fig. 20 or the opening 27 is tapered and the discharge section 33 is straight as shown in Fig. 21. The spring receiving surface 47 of the spring receiving section 34 may be flat. As shown in Figs. 22 and 23, the notch 41 constituting the injection opening 42 may be formed on the semicylindrical member 31A of the nozzle tip 22 and in opposition to the notch 41, a flat surface 69 parallel with the axis ℓ₂ may be formed on the other semicylindrical member 31B. Further, as shown in Figs. 24 through 26, a sleeve 71 may be interposed between the spring receiving section 34 and the spring 23. That is, the construction of the above embodiment is that the semispherical section 44 of the semicylindrical members 31A and 31B is perpendicular, on the discharge section side thereof, to the axis ℓ₂ and cut-outs 72 and 72 formed in the periphery of the nozzle tip 22 engage a pair of opposed projections 73 and 73 formed in the lower end portion of the sleeve 71 into which the cylindrical section 32 is slidably inserted. Accordingly, as shown in Fig. 27, in a self-cleaning operation, the projections 73 and 73 of the sleeve 71 urged by the spring 23 urge the semicylindrical members 31A and 31B, respectively constituting the nozzle tip 22. Consequently, the forward end of the nozzle tip 22 is opened. The engagement between the cut-out 72 and the projection 73 prevents the nozzle tip 22 from rotating about the axis ℓ₂ and returns the self-cleaning condition to the atomizing condition. Further, the spring receiving section 34 of the nozzle tip 22 is urged through the sleeve 71, the type of the spring 23 is not limited. As described above, the diameter of the fluid path according to the self-cleaning nozzle of the present invention is greater than the diameter of the fluid path of the conventional nozzle. Therefore, foreign matter does not collect in the fluid path as much as the conventional nozzle and can be reliably discharged outside by dropping the atomization pressure below the resilience of the spring. Further, fluid is atomized in the axial direction of the nozzle, namely, the axial direction of the thread for mounting the nozzle on a pipe. Accordingly, the atomization distribution and atomization region do not change greatly even though the nozzle is mounted on the pipe in a different direction and as such, it is unnecessary to position the nozzle with a high accuracy and further, the nozzle can be easily mounted on the pipe with the tapered thread. This construction eliminates the use of parts such as a lock nut for improving the nozzle positioning accuracy and an O-ring for preventing a fluid leakage and an operation for flattening the portion on which the nozzle is mounted. As such, the nozzle of the present invention can be mounted on the pipe with the use of a fewer number of parts, which simplifies the operation for mounting the nozzle on the pipe. In atomizing fluid a long distance by mounting a plurality of nozzles on the pipe, atomized fluid does not interfere with each other by mounting each nozzle on the pipe so that each nozzle makes a certain angle with the axis of the pipe. Further, according to the present invention, fluid can be atomized in various patterns or configurations by changing the configuration of the injection opening of the nozzle tip. Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention as defined by the appended claims unless they depart therefrom.

Claims: A nozzle comprising: a nozzle main body (21) which is cylindrical and has a fluid inlet (21b) provided on the backward side thereof and a tip engaging opening (27) provided on the forward side thereof; a nozzle tip (22) comprising: a plurality of members formed by dividing an approximately cylindrical member (31A, 31B) in the axial direction thereof; and a discharge section (33) having an injection opening in the forward end of said cylindrical member (31A, 31B); said nozzle tip (22) being accomodated in the interior of said nozzle main body (21) with said discharge section (33) slidably engaging said tip engaging opening (27) so that fluid flowing from a fluid inlet is atomized from said injection opening (42) through a fluid path (37, 38) extending along the axis of said nozzle main body (21); and wherein at least one of the peripherial surfaces of said discharge section (33) of said nozzle tip (22) and the inner peripheral surface of said tip engaging opening (27) of said nozzle main body (21) is tapered; and a part of said discharge section (33) of said nozzle tip (22) is engaged by a part of said tip engaging opening (27) during an atomization operation and during the self-cleaning operation in which said nozzle tip (22) moves backward said members (31A, 31B) of said nozzle tip (22) move away from each other so as to discharge foreign matter which has penetrated into said fluid path, characterized by a spring receiving section (28) projecting from the periphery of the backward side of said nozzle tip (22); and by a spring (23) provided between the spring receiving section (28) of said nozzle tip (22) and a wall positioned on the forward side of said nozzle main body (21), for urging said nozzle tip (22) toward the backward side when a self-cleaning operation is performed with the atomization pressure reduced. A nozzle as claimed in claim 1, wherein the axis of said nozzle main body (21) coincides with the axis of said fluid path (37, 38) and said injection opening (27) both extending along the axis of said approximately cylindrical nozzle tip (22) accomodated in the interior of said nozzle main body (21); and a thread for mounting said nozzle main body (21) on a fluid supply pipe is formed in the periphery of said nozzle main body (21) in such a manner that said thread is positioned on the backward side of said nozzle main body (21) and the axis of said thread coincides with that of said nozzle main body (21). A nozzle as claimed in claim 2, wherein the periphery of said nozzle main body (21) corresponding to the thread-formed portion is tapered. A nozzle as claimed in claim 1, wherein the periphery of said discharge section (33) of said spring receiving section (28) is tapered to forcibly open said discharge section (33) when said nozzle tip (22) is moved backward by the resilience of said spring (23) during the self-cleaning operation. A nozzle as claimed in claim 1, wherein the inner peripheral surface of said tip engaging opening (27) of said nozzle main body (21) and the peripheral surface of said discharge section (33) of said nozzle tip (22) are tapered so that said discharge section (33) of said nozzle tip (22) engages said tip engaging opening (27) in close contact therewith and the forward end of said discharge section (33) projects from the forward end surface of said nozzle main body (21). A nozzle as claimed in claim 1, wherein each end of said spring (23) is fixed to said spring receiving section (28) of said nozzle tip (22) and said nozzle main body (21) so that said spring (23) is nonrotatable and elastic.

Inventors: IWAMURA YOSHINARI, OKIMOTO KATSUNORI, SHIMIZU AKIO, IWAMURA, YOSHINARI, OKIMOTO, KATSUNORI, SHIMIZU, AKIO
Applicants: IKEUCHI KK, H. IKEUCHI & CO., LTD.
Application year: 1991
Main classification: B05B15
IPC codes: B05B1, B05B15, B08B3