Cleaning device

Abstract

To provide a cleaning device that can remove dust and other magnetic foreign matter adhering to the surface of rod-shaped objects such as magnetic bars, and effectively suppress the release of the removed dust into the surrounding environment. [Solution] A cleaning ring having a through hole into which a rod-shaped object to be cleaned is inserted from the upstream side toward the downstream side, wherein the surface of the through hole is provided with nozzles for ejecting a pressurized gas in the ejection direction containing a component directed toward the downstream side of the through hole, and a stepped portion is provided adjacent to the ejection nozzles, wherein the cross-sectional area perpendicular to the center line of the through hole expands toward the downstream side.

Description

Technical Field

[0001] The present invention relates to a cleaning device for removing dust adhering to the surface of a rod-shaped body having a substantially uniform cross-sectional shape. Background Art

[0002] In the process of manufacturing resins, foods, medicines, feeds, fertilizers and the like supplied in the form of powder, granules, liquid, fluid, etc., processing is often performed using cutters made of iron-based materials such as screw feeders, mixers, cutters, and shredders, and it is unavoidable that broken iron pieces generated due to damage of such cutters are mixed into products. In contrast, in order to ensure the safety of various products as described above, it is a common practice to provide various magnetic means on the path through which products are conveyed, so as to adsorb magnetic foreign matter mixed in the products and separate it from the products.

[0003] For example, Patent Document 1 describes an iron removal device in which a plurality of magnetic bars are arranged in an iron removal chamber to remove magnetic foreign matter from raw materials flowing down through the iron removal chamber by adsorbing the foreign matter with the magnetic bars. In addition, Patent Document 2 describes a technique of using a magnetic bar having a predetermined cross-sectional shape for a magnetic bar that adsorbs and removes magnetic foreign matter from raw materials. Furthermore, Patent Document 3, Patent Document 4, Patent Document 5, etc. also describe techniques for adsorbing and separating magnetic foreign matter mixed in products using predetermined magnetic bars.

[0004] As described above, by using a magnet bar capable of attracting magnetic foreign matter and bringing various products into contact with the surface of the magnet bar, it is possible to effectively separate magnetic foreign matter mixed into the products. On the other hand, when separating magnetic foreign matter from these various products, magnetic foreign matter accumulates on the surface of the magnet bar, increasing its volume and reducing its ability to attract new magnetic foreign matter. Furthermore, problems arise such as magnetic foreign matter that has been attracted to the magnet bar falling off and re-contaminating the products. Therefore, it is necessary to periodically remove the magnetic foreign matter accumulated on the surface of the magnet bar to maintain the magnet bar's ability to attract magnetic foreign matter.

[0005] Regarding the removal of magnetic foreign matter accumulated on the surface of the magnet bar, Patent Document 3 describes providing an air nozzle that sprays air toward the magnet bar for the purpose of removing the magnetic foreign matter accumulated on the magnet bar, and providing a means for spraying air from the air nozzle. Furthermore, Patent Document 5 describes a technique for mechanically removing magnetic foreign matter accumulated on the surface of the magnet bar by removing the magnet from a cylindrical body that constitutes the surface of the magnet bar and providing a ring that slides on the surface of the cylindrical body, thereby removing the magnetic field affecting the magnetic foreign matter. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2014-161787 [Patent Document 2] Japanese Patent Publication No. 2007-21348 [Patent Document 3] Japanese Patent Publication No. 2003-211022 [Patent Document 4] Japanese Patent Application Publication No. 8-10642 [Patent Document 5] Japanese Patent Application Publication No. 11-17633 [Overview of the project] [Problems that the invention aims to solve]

[0007] By removing magnetic foreign matter accumulated on the surface of the magnet bar using the means described in Patent Documents 3, 5, etc., the magnet bar's ability to attract magnetic foreign matter is restored, making it possible to continue the process of attracting and removing magnetic foreign matter from the product.

[0008] However, when magnetic foreign matter accumulated on the surface of a magnet bar is removed in the processing chamber using the methods described in Patent Documents 3 and 5, the removed magnetic foreign matter is re-released into the surrounding processing chamber. This necessitates a subsequent step of cleaning the processing chamber by other means to recover the re-released magnetic foreign matter, inevitably leading to a longer downtime for the equipment.

[0009] Therefore, depending on the type of product from which magnetic foreign matter is to be removed and the required level of cleanliness, it may be difficult to use methods that involve the re-release of magnetic foreign matter into the processing chamber, as described in Patent Documents 3, 5, etc., and it may be necessary for an operator to manually wipe off the magnetic foreign matter accumulated on the surface of the magnet bar using a cloth or the like.

[0010] The present invention aims to provide a cleaning device that can resolve the above-mentioned issues and remove dust such as magnetic foreign matter adhering to the surface of a rod-shaped object such as a magnet bar, while effectively suppressing the release of the removed dust into the surrounding environment. [Means for solving the problem]

[0011] To solve the above problems, the present invention provides the following means. (1) A cleaning ring having a through hole into which a rod-shaped object to be cleaned is inserted from the upstream side toward the downstream side, wherein the surface of the through hole is provided with nozzles for ejecting a pressurized gas in the ejection direction containing a component directed toward the downstream side of the through hole, and a stepped portion is provided adjacent to the nozzles for ejecting the gas, the step portion having a cross-sectional area perpendicular to the center line of the through hole that expands toward the downstream side. (2) The cleaning ring wherein, in a plane including the center line of the through hole and the outlet of the spray nozzle, the angle that the spray direction makes with respect to the center line of the through hole is in the range of 1 to 80 degrees. (3) The cleaning ring is provided with a centering means in the through hole to ensure airflow between the through hole and the rod-shaped object by preventing the rod-shaped object inserted into the through hole from coming into contact with the surface of the through hole. (4) The stepped portion is formed by a tapered surface that sequentially increases in cross-sectional area perpendicular to the center line of the through hole toward the downstream side, and the spray nozzle is provided protruding from the tapered surface. (5) The spray nozzle is the cleaning ring formed inside the rib formed on the tapered surface. (6) The cleaning ring provided with an annular magnetic material surrounding at least a portion of the through hole. (7) A cleaning device including the cleaning ring described above. (8) The cleaning device having a depressurization means for reducing the pressure inside the through hole toward the downstream side. [Effects of the Invention]

[0012] According to the cleaning ring of the present invention, it is possible to remove dust such as magnetic foreign matter adhering to the surface of a rod-shaped object such as a magnet bar while suppressing its re-release into the surrounding environment. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram showing an example of how to use a cleaning device including the cleaning ring 10 according to the present invention. [Figure 2] This is a schematic diagram showing an example of the cleaning ring 10 according to the present invention. [Figure 3] This is a schematic diagram illustrating the function of the stepped portion of the cleaning ring 10 according to the present invention. [Figure 4] This is a schematic diagram showing the shape of the stepped portion of the cleaning ring 10 according to the present invention. [Figure 5] This is a schematic diagram showing the shape of the stepped portion of the cleaning ring 10 according to the present invention. [Figure 6] It is a schematic diagram showing another example of the cleaning ring 10 according to the present invention. [Figure 7] It is a schematic diagram showing an example of centering means used in the cleaning ring 10 according to the present invention. [Figure 8] It is a schematic diagram showing another example of the cleaning ring 10 according to the present invention. [Figure 9] It is a schematic diagram showing an example of an embodiment of the cleaning ring 10 according to the present invention. [Figure 10] It is a schematic diagram showing another embodiment of the cleaning ring 10 according to the present invention. [Figure 11] It is a schematic diagram showing another example of the cleaning ring 10 according to the present invention. [Figure 12] It is a schematic diagram showing another embodiment of the cleaning ring 10 according to the present invention. [Figure 13] It is a schematic diagram showing the form of the cleaning ring 10 used in examples of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] In order to remove and collect dust adhering to the surface of a rod-shaped body such as a magnet bar while suppressing re-release of the dust to the surroundings, it is desired, for example, to remove the dust by suction using an appropriate suction means. On the other hand, particularly magnetic foreign matter adhering to the surface of a magnet bar is magnetically attracted strongly to the magnet bar, so it is difficult to detach and collect the magnetic foreign matter from the magnet bar by suction with a general vacuum cleaner or the like. When efficiently detaching magnetic foreign matter, it is desirable to employ, for example, blowing of air or the like as described in Patent Document 3 and the like. On the other hand, as described above, when air or the like is simply blown onto magnetic foreign matter adhering to the surface of a magnet bar, there arises a problem that the magnetic foreign matter is re-released into the environment.

[0015] The inventors of this invention conducted various studies on the aforementioned problem and discovered that by blowing air or the like onto the surface of a magnet bar to which magnetic foreign matter is attached under predetermined conditions, the magnetic foreign matter can be efficiently detached from the magnet bar by the pressure of the air or the like, and the re-release of the detached magnetic foreign matter into the environment can be suppressed, leading to the present invention. While the cleaning ring 10 according to the present invention is preferably used to detach and remove magnetic foreign matter 25 from a magnet bar capable of magnetically attracting such foreign matter 25, the use of the cleaning ring 10 according to the present invention is not limited to this, and it can be widely used to clean rod-shaped objects to which foreign matter has adhered.

[0016] Figure 1 schematically shows an example of a configuration in which a cleaning device including the cleaning ring 10 according to the present invention is used. The cleaning device according to the present invention can be preferably used for rod-shaped objects 20 such as magnet bars that have a rod-shaped outer shape because they have a substantially uniform cross-sectional shape. Magnet bars can attract magnetic foreign matter to their surface by having a permanent magnet inside, and by coming into contact with various objects to be processed, they can attract and remove magnetic foreign matter 25 contained in the objects to be processed.

[0017] As shown in Figure 1, the cleaning ring 10 according to the present invention can be preferably used as a means to clean the surface of a rod-shaped object 20 such as a magnet bar by spraying a pressurized gas 9 such as compressed air from a nozzle 1 to detach magnetic foreign matter 25 and the like that has been adsorbed onto the rod-shaped object 20.

[0018] Figure 2 schematically shows an example of the configuration of the cleaning ring 10 according to the present invention. The cleaning ring 10 according to the present invention has a through hole 4 into which a rod-shaped object 20 such as a magnetic bar can be inserted, and the through hole 4 has two openings, and the rod-shaped object 20 is formed to be inserted from the upstream opening 8 and to protrude from the downstream opening 9.

[0019] Furthermore, it is desirable that a shielding means 11 is connected by appropriate means to the downstream opening 9 of the cleaning ring 10 to prevent magnetic foreign matter 25 and the like from detaching from the rod-shaped object 20 and being released into the outside space, thereby preventing magnetic foreign matter 25 and the like that detached from the rod-shaped object 20 from being released back into the environment when the rod-shaped object 20 is cleaned.

[0020] The shape and size of the cross-section of the through-hole 4 can be appropriately determined according to the cross-sectional shape of the rod-shaped object to be cleaned. However, in order to efficiently remove the magnetic foreign matter 25 with the pressurized gas 13 blown from the ejection nozzle 1 described later, it is preferable that the cross-section of the through-hole 4 be approximately similar to that of the rod-shaped object 20 to be cleaned. This creates a gap of approximately uniform intervals between the inner surface of the through-hole 4 and the surface of the rod-shaped object 20 in the circumferential direction of the rod-shaped object 20 when the rod-shaped object is inserted along the center line of the through-hole 4.

[0021] Regarding the cross-sectional shape of the through-hole 4, for example, in a cleaning ring 10 used for cleaning a rod-shaped object 20 having a circular cross-section, the shape of the part of the through-hole 4 with the smallest cross-sectional area is made into a circle with a radius approximately 0.2 to 10 mm larger than the cross-section of the rod-shaped object 20, and the nozzle of the spray nozzle 1 is provided near the part of the through-hole 4 with the smallest cross-sectional area. This allows the rod-shaped object 20 to be easily inserted into the through-hole 4, and the nozzle of the spray nozzle 1 is positioned near the rod-shaped object 20, enabling effective cleaning of the surface of the rod-shaped object 20.

[0022] Furthermore, even when the cross-sectional shape of the rod-shaped object 20 to be cleaned is rectangular, oval, or oval, the shape of the point where the cross-sectional area of ​​the through-hole 4 is smallest is made to be approximately similar to the cross-sectional shape of the rod-shaped object 20, and when the rod-shaped object 20 is inserted along the center line of the through-hole 4, the average gap between the rod-shaped object 20 and the upstream opening 8 is approximately 0.1 to 10 mm. By providing the nozzle of the spray nozzle 1 near the point where the cross-sectional area of ​​the through-hole 4 is smallest, it becomes possible to clean the surface of the rod-shaped object 20 effectively.

[0023] It is preferable that the cleaning ring 10 is provided with a communication path 5 for supplying pressurized gas to the ejection nozzles 1, and a supply path 6 for supplying pressurized gas to the communication path 5, thereby enabling the pressurized gas 13 to be released from each ejection nozzle 1. The external shape of the cleaning ring 10 is not particularly limited, and it can be shaped appropriately to avoid items that are present around the rod-shaped object 20 to be cleaned and would obstruct the use of the cleaning ring 10, or to take into consideration the need to hold the cleaning ring 10 in the cleaning device.

[0024] The cleaning ring 10 used for cleaning the above-mentioned magnet bar is mainly made of a non-magnetic material such as metal, resin, or ceramics that does not attract to magnets, so that it does not come into contact with the magnet bar when cleaning, making cleaning easier. On the other hand, when cleaning the magnet bar, it is possible to make at least a part of the cleaning ring 10 a magnetic material that attracts to magnets, depending on the purpose, such as adjusting the distribution of magnetic field lines emitted from the magnet bar.

[0025] The cleaning ring 10 according to the present invention cleans a rod-shaped object 20 by ejecting a pressurized gas 13, such as compressed air, from a plurality of ejection nozzles 1 provided on the inner surface of its through-hole 4, and removing magnetic foreign matter 25 and the like that adsorbed on the surface of the rod-shaped object 20 that has been inserted into the through-hole 4 by the flow of the pressurized gas 13.

[0026] In the cleaning ring 10 according to the present invention, the ejection nozzle 1 is provided such that, within a cross-section including the center line of the through hole 4, the ejection direction of the pressurized gas 13 from the ejection nozzle 1 forms an angle θ of less than 90 degrees with respect to the center line. By setting this angle to less than 90 degrees, the flow of the pressurized gas 13 released from the ejection nozzle 1 has a velocity component in the direction from the upstream opening 8 to the downstream opening 9 of the through hole 4. This flow accelerates the gas inside the through hole 4 toward the downstream opening 9, thereby inducing a gas flow inside the through hole 4 from the upstream opening 8 to the downstream opening 9.

[0027] As a result of the gas flow induced inside the through-hole 4 from the upstream opening 8 to the downstream opening 9, the pressure inside the through-hole 4 decreases compared to the outside of the upstream opening 8, according to Bernoulli's theorem, and it becomes possible to induce an airflow from the upstream opening 8 into the through-hole 4. This airflow allows magnetic foreign matter 25 and the like that detached from the surface of the rod-shaped object 20 to be transported to the downstream opening 9, making it possible to clean the rod-shaped object 20 while preventing the magnetic foreign matter 25 and the like from being released back into the surrounding environment.

[0028] In the plane containing the centerlines of the ejection nozzle 1 and the through-hole 4, the angle θ formed by the centerline of the through-hole 4 and the direction of ejection of pressurized gas from the ejection nozzle 1 can be in the range of 1 to 85 degrees. In this invention, when referring to the direction of ejection of pressurized gas from the ejection nozzle 1, it means the direction toward the interior of the through-hole 4 along the centerline of the ejection nozzle 1. As the angle θ decreases and the direction of pressurized gas ejection approaches parallel to the center line of the through-hole 4, the flow velocity of the gas induced inside the through-hole 4 toward the downstream opening 9 increases, even when the pressurized gas is ejected under the same conditions. This effectively prevents magnetic foreign matter 25 detached from the surface of the rod-shaped object 20 from flowing back into the upstream opening 8. On the other hand, by increasing the angle θ, it is possible to increase the flow velocity of the pressurized gas blown onto the magnetic foreign matter 25 when inserting a rod-shaped object into the through-hole 4 to remove it, thereby improving the removal capacity of the magnetic foreign matter 25.

[0029] When using the cleaning ring 10 according to the present invention to remove magnetic foreign matter 25 etc. that is magnetically attracted to a magnet bar that generates a strong magnetic field, setting the angle θ to 1 to 70 degrees makes it possible to remove the magnetic foreign matter 25 etc. effectively. On the other hand, when cleaning a rod-shaped body to which dust has adhered due to machining or various handling, the dust can be removed relatively easily, so setting the angle θ to 30 to 60 degrees increases the flow velocity of the gas inside the through hole 4, making it possible to prevent backflow towards the upstream opening 8 more effectively.

[0030] In this invention, when referring to the center line of the through hole 4, it means the line connecting the centroids of the smallest area cross-sections (hereinafter sometimes referred to as "minimum area cross-sections") within the cross-section of the through hole 4 that includes any point inside the through hole 4. For example, if each minimum area cross-section of the through hole 4 is circular, it means the line connecting the centers of each of those circles. Furthermore, the following description will focus on the case where the center line is a straight line, but the present invention is not limited thereto. For example, in a cleaning ring 10 used to clean a rod-shaped object with a constant curvature arc, the arc can be the center line of the through hole 4.

[0031] It is desirable that the multiple injection nozzles 1 described above be arranged on the surface of the through-hole 4 in such a manner that pressurized gas is uniformly injected onto the rod-shaped object inserted into the through-hole 4, and a uniform gas flow is induced inside the through-hole 4, for example, by arranging them at a uniform density on the circumference where a circle perpendicular to the center line of the through-hole 4 intersects with the surface of the through-hole 4. Furthermore, since the pressure of the pressurized gas blown onto the surface of the rod-shaped object increases as the nozzle outlet of the injection nozzle 1 approaches the surface of the rod-shaped object into which it is inserted, it is preferable to place the nozzle outlet of the injection nozzle 1 near the point where the cross-sectional area of ​​the through-hole 4, which is provided to be approximately similar in shape to the cross-sectional shape of the rod-shaped object, is smallest, as described above.

[0032] When the rod-shaped object 20 is inserted along the center line of the through-hole 4, by setting the average distance between the surface of the rod-shaped object and the nozzle of the injection nozzle 1 to approximately 0.1 mm or more, the pressurized gas injected from the injection nozzle 1 can flow smoothly between the through-hole and the rod-shaped object. Furthermore, by setting the average distance between the surface of the rod-shaped object and the nozzle of the injection nozzle 1 to approximately 0.1 to 2 mm, a large volume of pressurized gas can flow between the through-hole and the rod-shaped object, enabling effective transport and removal of magnetic foreign matter 25 and the like that detached from the rod-shaped object.

[0033] The direction of discharge of pressurized gas from the multiple discharge nozzles 1 provided in the cleaning ring 10 does not necessarily have to be the same with respect to the center line of the through hole 4. Within the range where the angle θ with respect to the discharge direction from each discharge nozzle 1 is less than 90, it is possible to discharge pressurized gas from each discharge nozzle 1 in mutually different discharge directions. By keeping the average angle within the above range, it is possible to effectively detach magnetic foreign matter 25 etc. from the rod-shaped object 20 and prevent backflow of the detached magnetic foreign matter 25 etc. towards the upstream opening 8.

[0034] Furthermore, the direction of the pressurized gas ejected from each ejection nozzle 1 does not necessarily have to be directed towards the center line of the through hole. By making the ejection direction have a component in the circumferential direction of the through hole, it is possible to form a vortex flow inside the through hole 4, which is an effective means of reducing the flow resistance of air and other materials inside the through hole 4. Furthermore, the injection nozzle 1 is not necessarily limited to mutually independent holes; for example, by making it a slit shape that opens with a predetermined width from the communication path 5 toward the through hole 4, the amount of pressurized gas ejected can be easily adjusted by adjusting the width of the slit.

[0035] In the cleaning ring 10 according to the present invention, a stepped portion 3 can be provided in the direction from the upstream opening 8 to the downstream opening 9 of the through hole 4, such that the cross-sectional area of ​​the through hole 4 increases. Furthermore, it is desirable that the stepped portion 3 be provided in close proximity to the spray nozzle 1. In this invention, when it is stated that the stepped portion 3 and the spray nozzle 1 are in close proximity, it means that at least a portion of the opening of the spray nozzle 1 overlaps with the stepped portion. As shown in Figure 2, when the stepped portion 3 is provided in a tapered shape, by positioning the injection nozzle 1 at a location where the cross-sectional area of ​​the through-hole 4 begins to increase due to the tapered portion, the opening of the injection nozzle 1 approaches the rod-shaped object into which it is inserted, thereby achieving a high ability to remove magnetic foreign matter 25 and the like. Furthermore, by positioning the injection nozzle 1 inside the tapered portion, it becomes possible to effectively suppress the release of pressurized gas from the upstream opening 8, as described below.

[0036] Figure 3 shows a schematic comparison of two cases: one where the stepped portion 3 is not provided on the surface of the through-hole 4 and the injection nozzle 1 is provided on the surface of the through-hole 4 parallel to its centerline (Figure 3(A)), and another where the stepped portion 3 is provided close to the injection nozzle 1 (Figure 3(B)). As described above, the through-hole 4 of the cleaning ring 10 according to the present invention is formed such that when a rod-shaped object 20 to be cleaned is inserted along its centerline, a gap of about 0.2 to 10 mm is created between the surface of the through-hole 4 and the surface of the rod-shaped object 20, allowing pressurized gas to flow smoothly between the through-hole 4 and the rod-shaped object 20. Furthermore, since the direction of ejection of the pressurized gas ejected from the injection nozzle 1 has a component directed toward the downstream opening 9 as described above, a gas flow 12 is formed inside the through-hole 4 from the upstream opening 8 toward the downstream opening 9 (states A-1 and B-1 in Figure 3), making it possible to transport magnetic foreign matter 25 detached from the rod-shaped object 20 toward the downstream opening 9.

[0037] On the other hand, as shown in (A) in Figure 3, if a spray nozzle 1 is provided on the surface of the through-hole 4 parallel to its center line, for example, when an operator holds either the through-hole 4 or the rod-shaped object 20 and inserts the rod-shaped object 20 into the through-hole 4, pressurized gas ejected from the spray nozzle 1 is released from the upstream opening 8, and as a result of the release of the pressurized gas, magnetic foreign matter 25 and the like that detached from the rod-shaped object 20 are released to the outside of the cleaning ring 10.

[0038] As described above, it is presumed that the reason why the pressurized gas ejected from the nozzle 1 is released from the upstream opening 8 is due to the mechanism shown in A-2 of Figure 3. In other words, when the injection nozzle 1 is provided on the surface of the through-hole 4 parallel to the center line of the through-hole 4, when the through-hole 4 and the surface of the rod-shaped object 20 come into close proximity, the space around the nozzle of the predetermined injection nozzle 1 narrows. As a result, the pressurized gas ejected from the injection nozzle 1 increases the pressure around the nozzle, and this pressure forms a gas flow 12' toward the upstream opening 8, causing the pressurized gas to be released from the upstream opening 8.

[0039] As a means to prevent the release of pressurized gas from the upstream opening 8 as described above, a stepped portion 3 is provided adjacent to the injection nozzle 1 in a direction that widens the space on the downstream opening 9 side (B-1). This ensures that even when a rod-shaped object 20 approaches the surface of the through hole 4, a path is secured for the pressurized gas ejected from the injection nozzle 1 to flow toward the downstream opening 9, preventing a pressure increase near the nozzle of the injection nozzle 1, and allowing the inflow of air from the upstream opening 8 to continue due to the flow toward the downstream opening 9 (B-2).

[0040] The stepped portion 3 provided on the surface of the through-hole 4 is not particularly limited in shape, as long as it widens the cross-sectional area of ​​the through-hole 4 on the downstream opening 9 side of the cleaning ring 10. Figure 4 schematically shows the form of the stepped portion 3 provided on the surface of the through-hole 4. As shown in Figure 4(a), by forming the stepped portion 3 with a tapered shape that widens the cross-sectional area of ​​the through-hole 4 at a predetermined angle α, it is possible to ensure a flow path for the pressurized gas ejected from the ejection nozzle 1 while preventing stagnation in the gas flow inside the through-hole 4. Furthermore, as shown in Figure 4(b), by forming the stepped portion 3 with a surface substantially perpendicular to the center line of the through-hole 4 and including at least a part of the outlet of the ejection nozzle 1 on this surface, it is possible to reliably ensure a flow path for the pressurized gas ejected from the ejection nozzle 1 even when a rod-shaped object to be cleaned comes into contact with the surface of the through-hole 4.

[0041] Furthermore, as shown in Figure 4(c), within the stepped portion 3 provided on the surface of the through-hole 4, it is possible to provide a nozzle 101 with a different angle and opening position from the nozzle 1, which is provided in a cross section containing the same or different centerlines of the through-hole 4, in relation to the nozzle 1 provided in a cross section containing the centerline of a predetermined through-hole 4. As shown in the nozzle 1 in Figure 4(c), by providing the nozzle outlet at the position where the increase in the cross-sectional area of ​​the through-hole 4 due to the stepped portion 3 begins, the nozzle outlet can be positioned near the rod-shaped object, thereby increasing the ability to remove magnetic foreign matter 25 and the like adsorbed on the surface of the rod-shaped object. On the other hand, by positioning the opening of the nozzle 1 away from the surface of the rod-shaped object, it is possible to effectively prevent pressurized gas from flowing out of the upstream opening 8 due to changes in the position of the rod-shaped object.

[0042] Furthermore, as shown in Figure 4(d), by utilizing the stepped portion 3, a discharge nozzle 102 that releases pressurized gas in a direction substantially parallel to the center line of the through-hole 4 can be provided together with the discharge nozzle 1, thereby strengthening the flow of gas inside the through-hole 4 toward the downstream opening 9.

[0043] Figure 5 schematically shows another configuration of the arrangement of the ejection nozzle 1 with respect to the stepped portion 3 provided on the surface of the through hole 4. Figure 5(a) is a schematic cross-section including the center line of the through hole 4 and the ejection nozzle 1, and Figure 5(b) shows the cross-section connecting the ejection nozzle 1 (cross-section aa in Figure 5(a)). In the configuration shown in Figure 5, the stepped portion 3 is made up of a tapered surface, and the ejection nozzle 1 is provided protruding from the tapered surface, so that its nozzle is positioned near the rod-shaped object that penetrates the through hole 4, making it possible to maintain a high ability to remove magnetic foreign matter 25 and the like adsorbed on the rod-shaped object.

[0044] The form in which the ejection nozzle 1 protrudes from the tapered surface is not particularly limited. For example, the metal tube constituting the ejection nozzle may be made to protrude from the tapered surface. Alternatively, as shown in Figure 5, a groove 30 may be formed between the ejection ports of a plurality of ejection nozzles 1 provided on the surface of the through hole 4 (Figure 5(b)), and as a result, the ejection nozzle 1 may be provided inside the ribs separating the groove 30. In the configuration shown in Figure 5(b), the depth of the groove 30 increases toward the downstream side, increasing the cross-sectional area of ​​the through hole 4 and forming part of the stepped portion 3. Furthermore, even when a rod-shaped object approaches and comes into contact with the nozzle of the ejection nozzle 1, the pressurized gas released from the nozzle flows into the groove 30 and flows toward the downstream opening 9, effectively preventing the pressurized gas from being released from the upstream opening 8.

[0045] Figure 6 schematically shows another embodiment of the cleaning ring 10 according to the present invention. The cleaning ring 10 shown in Figure 6 is provided with a centering means 15 to prevent the center line of the rod-shaped body 20 that penetrates into the through hole 4 from deviating significantly from the center line of the through hole 4.

[0046] As described above, in the cleaning ring 10 according to the present invention, foreign matter attached to the rod-shaped body 20 is removed by blowing pressurized gas onto the rod-shaped body 20 to be cleaned, and the flux of the pressurized gas creates a flow of gas (air) inside the through hole 14 of the cleaning ring 10, which then transports and collects the removed foreign matter. On the other hand, as shown in Figure 3, etc., when the pressurized gas nozzle and the rod-shaped body are too close together, the ejected pressurized gas accumulates, resulting in the problem of the pressurized gas flowing out of the upstream opening 8 of the cleaning ring 10 along with the foreign matter.

[0047] The centering means 15 prevents the center line of the rod-shaped body 20, which is inserted into the through hole 4, from deviating excessively from the center line of the through hole 4, thereby maintaining the distance between the nozzle of the ejection nozzle 1 provided on the surface of the through hole 4 and the surface of the rod-shaped body 20, and effectively preventing backflow of pressurized gas. The centering means 15 is preferably provided on the upstream and downstream sides of the stepped portion 3 as shown in Figure 5, but is not limited to this, and can be provided on either side. It is also possible to provide the centering means 15 on the stepped portion 3 to the extent that it does not obstruct the ejection of pressurized gas from the ejection nozzle 1.

[0048] The centering means 15 can have an appropriate structure within a range that can properly regulate the position of the rod-shaped body 20 inserted into the through hole 4. Figure 7 schematically shows an example of the structure of the centering means 15. The centering means 15 shown in Figure 7 is preferably used for a rod-shaped body 20 having a circular cross-section, and by providing a plurality of ribs 16 inside the centering means 15 to define a circular penetration space 17 into which the rod-shaped body 20 can penetrate, it is possible to properly regulate the position of the rod-shaped body 20 within a range that does not obstruct the flow of gas through the centering means 15.

[0049] The shape and size of the penetration space 17 shown in Figure 7 can be appropriately determined according to the cross-sectional shape of the rod-shaped object to be cleaned. In particular, it is preferable to make the space approximately similar in shape to the cross-sectional shape of the rod-shaped object 20 to be cleaned, and to make it a small space that allows the rod-shaped object 20 to be easily penetrated. For example, by providing the penetration space 17 such that the distance between the rod-shaped object 20 and the rib 16 is about 0.1 to 1 mm, the through hole 4 and the center line of the rod-shaped object 20 can be substantially aligned. It is also possible to use the rib provided between the grooves 30 in the configuration shown in Figure 5 as a centering means.

[0050] Furthermore, by adjusting the shape and number of ribs 16, the proportion of the area not blocked by the ribs 16 within the area obtained by subtracting the area of ​​the penetration space 17 from the area demarcated by the centering means 15 can be set to 30% or more, preferably 50% or more, or 80% or more. This ensures ventilation when the rod-shaped object 20 is penetrated through the centering means 15, and suppresses a decrease in ventilation inside the through hole 4 caused by the centering means 15.

[0051] Figure 8 schematically shows another embodiment of the cleaning ring 10 according to the present invention. The ejection nozzle 1 provided in the cleaning ring 10 is provided near the upstream opening 8, and for the purpose of improving the cleaning ability of the rod-shaped object 20 and improving the flow flux of gas (atmosphere) inside the through hole 4, for example, a second ejection nozzle 1' or a third ejection nozzle 1'' can be provided downstream of the stepped portion.

[0052] By ejecting pressurized gas containing a directional component toward the downstream opening 9 from the second ejection nozzle 1' and the third ejection nozzle 1'', the ejection can promote the detachment of magnetic foreign matter 25 and the like adsorbed on the rod-shaped object 20, and the flux of gas (atmosphere) inside the through hole 4 toward the downstream opening 9 can be improved, thereby suppressing the ejection of pressurized gas from the upstream opening 8.

[0053] Furthermore, by providing the second ejection nozzle 1' etc. at the tip of the rib 16 provided as the centering means 15, pressurized gas can be injected from near the rod-shaped object 20, and even if the rod-shaped object 20 comes into contact with the rib 16 or the ejection nozzle's outlet is blocked, the pressurized gas will flow in the circumferential direction of the through hole 4, making it less likely for pressurized gas to be ejected from the upstream opening 8.

[0054] Figure 9 schematically shows another embodiment of the cleaning ring 10 according to the present invention. As shown in Figure 9, by providing a depressurization means 18 such as a vacuum cleaner or vacuum pump that depressurizes the inside of the through hole or the shielding means 11 connected to the cleaning ring, the inflow of air from the upstream opening 8 can be promoted, thereby making it less likely for pressurized gas to be ejected from the upstream opening 8.

[0055] Within a range where the pressure inside the through-hole can be reduced to promote the inflow of air from the upstream opening 8, the structure of the pressure reduction means is not particularly limited. For example, as shown in Figure 9(a), the pressure inside the through-hole can be reduced by a vacuum pump or the like, or as shown in Figure 9(b), the pressure inside the through-hole can be reduced by providing an injection nozzle 103 that injects pressurized gas having a flux directed downstream of the gas flow path, thereby promoting the flow of gas downstream.

[0056] When using the cleaning ring 10 according to the present invention in the form shown in Figure 1 to remove magnetic foreign matter 25 and the like that adsorbed to a rod-shaped object 20, it is preferable to position the nozzle of the ejection nozzle 1 very close to the end face of the upstream opening 8 so that the nozzle can reach the vicinity of the rod-shaped object holding means 21. On the other hand, by increasing the distance between the nozzle outlet of the nozzle 1 and the upstream opening 8, even if a localized flow toward the upstream opening 8 occurs near the nozzle outlet of the nozzle 1, the surrounding gas flux toward the downstream opening 9 will eliminate the flow toward the upstream opening 8, and the ejection of pressurized gas from the upstream opening 8 will be suppressed. Therefore, it is desirable to increase the distance between the nozzle outlet and the upstream opening 8 to the extent that it does not interfere with the cleaning of rod-shaped objects.

[0057] For example, it is desirable to position the ejection nozzle 1 closest to the upstream opening 8 at a distance of approximately 5 to 10 mm, more preferably 15 mm or more, from the upstream opening 8. This effectively suppresses the localized flow towards the upstream opening 8 from reaching the upstream opening 8.

[0058] Furthermore, by providing a predetermined shape of irregularities on the surface of the through-hole 4 between the upstream opening 8 and the nozzle of the ejection nozzle 1, the effective flow path of the gas between the surface of the through-hole 4 and the rod-shaped object being inserted can be extended. Additionally, by providing a means to suppress backflow of gas that creates flow resistance, it is possible to suppress the flow toward the upstream opening 8 that is locally generated by the surrounding gas flux toward the downstream opening 9.

[0059] As a means of suppressing backflow, for example, a spiral groove can be formed on the surface of the through-hole 4 to extend the flow path of the gas flowing between the surface of the through-hole 4 and the rod-shaped object until it reaches the upstream opening 8, or an irregularity can be provided on the surface of the through-hole 4 to increase the frictional force applied to the gas flowing between the surface of the through-hole 4 and the rod-shaped object. In addition, a centering means can be provided between the upstream opening 8 and the nozzle of the ejection nozzle 1, in which the ribs 16 constituting the centering means 15 are not parallel to the center line of the through-hole 4, thereby suppressing backflow that occurs locally toward the upstream opening 8.

[0060] Figure 10 schematically shows another embodiment of the cleaning ring 10 according to the present invention. In the embodiment shown in Figure 10, a dust cover 7 is provided around the cleaning ring 10. As shown in Figure 10(a), by providing the dust cover 7 so that its end protrudes further upstream than the upstream opening 8 of the cleaning ring 10, even when pressurized gas ejected from the ejection nozzle 1 and impacting the rod-shaped object 20 flows out from the upstream opening 8, it is possible to suppress the release of magnetic foreign matter 25 and the like detached from the rod-shaped object 20 into the environment by the flow of gas 12 into the dust cover 7.

[0061] Furthermore, by attaching the dust cover 7 to the cleaning ring 10 in a manner that allows it to slide in the direction of the center line of the through hole 4, and by biasing the end of the dust cover 7 with a spring or the like so that it protrudes upstream of the upstream opening 8, the dust cover 7 can be retracted relative to the cleaning ring 10, as shown in Figure 4(b). This makes it possible to penetrate the rod-shaped object 20 deeply without the dust cover 7.

[0062] Furthermore, by allowing gas to flow between the cleaning ring 10 and the dust cover 7, even when the end of the dust cover 7 comes into contact with the holding means 21 of the rod-shaped object 20, the airflow 12 between the cleaning ring 10 and the dust cover 7 can maintain the airflow within the through hole 4. In Figure 10, the dust cover 7 can be slid relative to the cleaning ring 10.

[0063] While an example of fixing it in place is shown, the present invention is not limited thereto. By shielding the area around the cleaning ring 10 with a dust cover 7 held by appropriate means, it is possible to suppress the release of magnetic foreign matter 25 and the like detached from the rod-shaped object 20 into the air.

[0064] Figure 11 schematically shows another embodiment of the cleaning ring 10 according to the present invention. In the embodiment shown in Figure 11, an annular magnetic body 19 is provided so as to surround the through hole 4. In a magnet bar from which magnetic foreign matter adsorbed on its surface is removed by a cleaning ring according to the present invention, N poles and S poles exist on the surface of the magnet bar, and the magnetic foreign matter is adsorbed to the surface of the magnet bar by the interaction between the magnetic field lines present between these magnetic poles and the magnetic foreign matter. Since the distribution of these magnetic field lines changes depending on the magnetic material present around the magnetic poles, the distribution and density of magnetic field lines near the surface of the magnet bar are changed by arranging an annular magnetic material 19 so as to surround the through hole 4, thereby changing the detachability of magnetic foreign matter adsorbed on the magnet bar.

[0065] The annular magnetic body 19, which is positioned to surround the through-hole 4, is preferably large enough to encompass both the north and south poles present in the magnet bar. This increases the density of magnetic field lines passing through the magnetic body, thereby changing the distribution of magnetic field lines near magnetic foreign matter attracted to the magnet bar.

[0066] Figure 12 schematically shows another embodiment of the cleaning ring 10 according to the present invention. By using multiple cleaning rings 10 according to the present invention and fixing them to predetermined positions relative to each other by shielding means 11, etc., a cleaning device capable of simultaneously cleaning multiple rod-shaped objects 20 can be constructed.

[0067] In this process, by reducing the pressure inside the shielding means 11 using a depressurizing means 18 such as a vacuum pump, an airflow is formed inside the through-hole 4 of the cleaning ring 10, directed towards the inside of the shielding means 11, thereby suppressing the release of magnetic foreign matter 25 and the like generated by the injection of pressurized gas from the cleaning ring 10 into the external environment. The present invention will be described in more detail below with reference to examples, but the present invention should not be interpreted as being limited to these examples. [Examples]

[0068] A magnet bar (25 mm in diameter, 200 mm in length) was used, consisting of a Fe-Nd rare earth magnet and a yoke material housed inside a Sus304 sheath. With the magnet bar fixed perpendicular to a Sus304 wall, approximately 1 g of iron powder was adsorbed onto the surface of the magnet bar (a rod-shaped object). Using this sample, the removal of the iron powder was attempted using the cleaning rings described in the following examples.

[0069] Figure 13 schematically shows the cleaning ring used for evaluation. Table 1 summarizes the diameter (a) of the upstream opening 8 of the cleaning ring in Figure 13, the diameter (b) downstream of the stepped portion 3, and whether or not the centering means 15 was used.

[0070] In each cleaning ring, the diameter of the spray nozzle 1 was set to φ1.5 mm, and 20 spray nozzles were uniformly arranged on the circumference of a circle 15 mm (dimension c) from the upstream opening 8. The angle (θ) between the spray direction of the spray nozzle 1 and the center line of the through hole 4 was set to 45 degrees. In Examples 1 to 3, the stepped portion 3 was composed of a tapered portion consisting of a conical surface with an angle (α) of approximately 15 degrees with respect to the center line of the through hole 4. In Examples 1 and 2, the spray nozzles were positioned to be included on the side of the upstream opening 8 of the tapered portion. In Example 3, grooves (see Figure 5) forming part of the conical surface were provided between each spray nozzle, so that each spray nozzle protruded from the tapered portion.

[0071] Each cleaning ring is made of a non-magnetic material that does not attract magnets, and the length between the upstream opening 8 and the downstream opening 9 is set to 220 mm. In addition, the centering means 15 is provided with eight ribs in the form shown in Figure 6, so that the diameter of the penetration space 17 is 25.5 mm, thereby suppressing the misalignment between the through hole 4 and the center line of the magnet bar.

[0072] [Table 1]

[0073] The evaluation is based on 8 kgf / cm² for each cleaning ring. 2 The cleaning was performed by connecting compressed air from the nozzle and spraying compressed air from the nozzle, while the operator held the cleaning ring by hand, penetrating a magnet bar to which a predetermined amount of iron powder had adhered, and cleaning by moving back and forth five times. The degree of compressed air ejection (backflow) from the upstream opening 8 and the amount of iron powder remaining on the surface of the magnet bar afterward were evaluated.

[0074] As shown in Table 1, when the diameter of the through hole was kept constant at 25.5 mm (comparative example), it was observed that air was well drawn in from the upstream opening 8 when the magnet bar was not inserted, while compressed air was ejected from the upstream opening 8 during the process of inserting the magnet bar. Furthermore, it was inferred that iron powder remained on the surface of the magnet bar after cleaning, and that the blowing of compressed air and the transport of detached iron powder were not being carried out properly.

[0075] On the other hand, when a stepped portion 3 was provided inside the through-hole 4 (Example 1), it was observed that the pressure of compressed air ejected from the upstream opening 8 decreased when penetrating and cleaning the magnet bar compared to the case without the stepped portion (Comparative Example). Furthermore, the amount of residual iron powder on the magnet bar surface after cleaning decreased, suggesting that the iron powder adsorbed by the compressed air blown by the cleaning ring was detached, and that the iron powder was transported to the downstream opening by the gas flow formed by the compressed air.

[0076] Furthermore, when a centering means was provided downstream of the stepped portion 3 inside the through hole 4 (Example 2), compressed air hardly ejected from the upstream opening 8 during cleaning, and it was inferred that the centering means effectively formed a gas flow inside the through hole 4 toward the downstream opening. Furthermore, when grooves were provided between the spray nozzles, and each spray nozzle was positioned to protrude from the tapered section (Example 3), it was observed that the amount of residual iron powder on the magnet bar surface after cleaning decreased compared to Example 2. This was presumed to be because providing grooves between the spray nozzles widened the space around the nozzle outlets, reducing the frequency with which iron powder detached from the magnet bar was reattached to the magnet bar, and also resulting in the iron powder being transported to the downstream opening. [Explanation of symbols]

[0077] 1. Discharge nozzle 3 Stepped section 4 through holes 5 Connecting Routes 6 Supply route 7. Dust cover 8 Upstream opening 9 Downstream opening 10 Cleaning Rings 11 Shielding means 13. Pressurized gas (compressed air) 15 Centering means 16 Ribs 17. Airway 18. Depressurization means 19 Magnetic material 20 rod-shaped bodies 21 Holding means 25 Magnetic foreign matter

Claims

1. A cleaning ring having a through hole into which a rod-shaped object to be cleaned is inserted from the upstream side toward the downstream side, The surface of the through-hole is provided with multiple nozzle outlets that eject pressurized gas in the injection direction, which contains components directed downstream of the through-hole, A cleaning ring characterized by having a stepped portion adjacent to the nozzle outlet of the spray nozzle, where the cross-sectional area perpendicular to the center line of the through hole expands toward the downstream side.

2. The cleaning ring according to claim 1, characterized in that, in a plane including the center line of the through hole and the nozzle outlet of the spray nozzle, the angle formed by the spray direction with respect to the center line of the through hole is in the range of 1 to 80 degrees.

3. The cleaning ring according to claim 1, characterized in that the through hole is provided with a centering means for ensuring ventilation between the through hole and the rod-shaped object by preventing the rod-shaped object inserted into the through hole from coming into contact with the surface of the through hole.

4. The cleaning ring according to claim 1, characterized in that the stepped portion is formed by a tapered surface that sequentially increases the cross-sectional area perpendicular to the center line of the through hole toward the downstream side, and the spray nozzle is provided protruding from the tapered surface.

5. The cleaning ring according to claim 4, characterized in that the spray nozzle is formed inside the rib formed on the tapered surface.

6. The cleaning ring according to claim 1, characterized in that an annular magnetic material is provided surrounding at least a portion of the through hole.

7. A cleaning device characterized by including a cleaning ring according to any one of claims 1 to 6.

8. The cleaning device according to claim 7, characterized in that it has a depressurization means for reducing the pressure inside the through hole toward the downstream side.

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