JP2003303714A - Bar magnet and magnetic material removing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bar magnet and a magnetic material removing device capable of removing fine foreign materials more surely. <P>SOLUTION: A bar magnet 10 includes a cylindrical vessel 12. In the container 12, a plurality of permanent magnets 14 comprising rare-earth magnets and yokes 16 are alternately arranged. The vessel 12 comprises a titanium alloy having a thickness of 0.1 mm to 0.5 mm, and the adjacent permanent magnets 14 are arranged in such a manner that the same poles face each other. The ratio of the thickness of the yoke 16 to that of the permanent magnet 14 is set at 1:20 to 6:20. A magnetic material removing device 20 is obtained by using a plurality of bar magnets 10. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bar magnet and a magnetic material removing device, and more particularly to food, rice grains, feed,
The present invention relates to a bar magnet and a magnetic substance removing device used to remove foreign substances made of metal such as iron powder from baits, residues, pharmaceuticals, chemicals, synthetic resins, and crushed waste.

[0002]

2. Description of the Related Art Conventionally, various techniques have been proposed for removing foreign substances made of metal such as iron powder from foods and the like. As an example, Japanese Utility Model Registration No. 3063633 discloses a foreign matter removing device. This foreign matter removing device has a round bar-shaped magnetic attraction tool installed transversely in a fluid transfer passage. The magnetic attraction device includes a plurality of disc-shaped magnets having magnetic poles at the ends in the axial direction, adjacent magnets are arranged so that the same poles face each other, and a plurality of magnets are provided between adjacent magnets and outside the end magnets. Interpose a piece of yoke. The magnet and the yoke in this state are loaded into a stainless steel circular pipe, and by welding stainless steel end plates to both ends of the circular pipe, the circular pipe is sealed and a magnetic attraction tool is formed. The thickness of the magnet used here is 5 m
m to 15 mm, and the yoke has a thickness of 1 to 3 mm.

[0003]

In recent years, it has been desired to remove foreign substances such as fine iron powder from raw materials such as foods and products, but in the above-mentioned prior art, the surface magnetic flux density of the magnetic attraction device is small and the foreign substances are small. Due to the weak magnetic force for sucking, it was not possible to sufficiently remove fine foreign matter. Therefore, a main object of the present invention is to provide a bar magnet and a magnetic substance removing device that can remove fine foreign matter more reliably.

[0004]

In order to achieve the above-mentioned object, a bar magnet according to claim 1 has a cylindrical container, a plurality of rare earth magnets housed in the container, and a container housed in and adjacent to each other. A yoke is inserted between matching rare earth magnets, the container is made of a titanium alloy having a wall thickness of 0.1 mm or more and 0.5 mm or less, and adjacent rare earth magnets are arranged so that the same poles face each other. And the rare earth magnet has a thickness ratio of 1:20 to 6:20. A bar magnet according to a second aspect is the bar magnet according to the first aspect, wherein the rare earth magnet is not provided with a corrosion resistant coating.

A magnetic substance removing device according to a third aspect includes a plurality of bar magnets according to the first or second aspect. A magnetic substance removing device according to a fourth aspect is the magnetic substance removing device according to the third aspect, wherein a plurality of bar magnets are arranged in parallel, and in adjacent bar magnets, a yoke included in one bar magnet and the other bar. It is characterized in that the yokes included in the magnet are arranged so that different poles face each other. According to a fifth aspect of the present invention, in the magnetic substance removing apparatus according to the third aspect, a plurality of bar magnets are arranged in parallel, and adjacent bar magnets include a yoke included in one bar magnet and the other bar. The yoke included in the magnet is characterized in that it is arranged so as not to partially overlap with each other in the direction orthogonal to the longitudinal direction of the bar magnet.

A magnetic substance removing apparatus according to a sixth aspect of the present invention includes a cylindrical container, a plurality of rare earth magnets mounted in the container, and a yoke mounted in the container and interposed between adjacent rare earth magnets. A plurality of bar magnets are provided, and in adjacent bar magnets, the yoke included in one bar magnet and the yoke included in the other bar magnet are arranged so that different poles face each other. The magnetic material removing device according to claim 7 is a bar magnet including a cylindrical container, a plurality of rare earth magnets that are installed in the container, and a yoke that is installed in the container and interposed between adjacent rare earth magnets. In a plurality of adjacent bar magnets, the yoke included in one bar magnet and the yoke included in the other bar magnet are arranged so as not to partially overlap with each other in the direction orthogonal to the longitudinal direction of the bar magnet. It is characterized by being done.

In the bar magnet according to the first aspect, the wall thickness of the container can be made as thin as 0.1 mm or more and 0.5 mm or less by using the titanium alloy for the container, and the rare earth magnet housed in the container is provided outside the bar magnet. Can be brought close to the surface. Therefore, the surface magnetic flux density of the bar magnet can be increased. Further, the attraction portion of the bar magnet is mainly near the yoke equivalent position, but if the thickness ratio of the yoke and the rare earth magnet is less than 1:20, that is, less than 0.05, even if the attraction force of the foreign matter is large, it will be commensurate with it. It is not possible to secure the attraction part of the above on the surface of the bar magnet. On the other hand, the thickness ratio of both is 6:
If it is larger than 20, that is, 0.3, the surface magnetic flux density of the bar magnet becomes small and the attraction force of the foreign matter becomes small. The thickness ratio of the yoke and the rare earth magnet is 1: 20-
By setting the ratio to 6:20, it is possible to secure a sufficiently large attracting portion on the surface of the bar magnet and to obtain a bar magnet having a desired surface magnetic flux density and thus a strong attractive force. Therefore, according to the bar magnet of the first aspect, it is possible to more reliably remove fine foreign matter.

In the rod magnet according to the second aspect, since the rare earth magnet is not provided with the corrosion resistant coating, the surface of the rare earth magnet can be brought closer to the surface of the rod magnet, and the surface magnetic flux density and attractive force of the rod magnet can be further improved. Can be made bigger. Claim 3
As described above, by using a plurality of bar magnets as described above, it is possible to obtain a magnetic body removing device that has a large attraction force and can remove fine foreign matter more reliably.

In the magnetic substance removing device according to the present invention, the yokes included in one of the bar magnets and the yokes included in the other bar magnet of adjacent bar magnets have different polarities. Since they are arranged, a large suction force is generated between both yokes. Therefore, the surface magnetic flux density near the yoke equivalent position of the bar magnet becomes larger. In the magnetic substance removing device according to claim 5 or 7, in the adjacent bar magnets, the yoke included in one bar magnet and the yoke included in the other bar magnet are in a direction orthogonal to the longitudinal direction of the bar magnets. Since they are arranged so that they do not partially overlap with each other, it is possible to create a wider area around the bar magnet that has a high spatial magnetic flux density above a certain level without creating an area with extremely low spatial magnetic flux density. .

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. Referring to FIG. 1, a bar magnet 10 according to an embodiment of the present invention includes a cylindrical container 12 having openings at both ends. For the container 12, it is preferable to use a non-magnetic material such as a titanium alloy and having high strength,
The wall thickness of the container 12 is set to 0.1 mm or more and 0.5 mm or less. If a titanium alloy is used for the container 12, even if foreign matter such as iron powder is attracted by a strong attraction force and adheres to the bar magnet 10 when removing the foreign matter, the deformation of the vessel 12 can be prevented. Also,
For example, in the case of stainless steel, it is difficult to reduce the wall thickness of the container due to manufacturing problems. However, by using a titanium alloy having excellent wear resistance, the wall thickness of the container 12 is 0.1 mm or more and 0.5 mm or less (as described above). In this embodiment, 0.
It can be made as thin as 3 mm. As a result, the permanent magnet 14 (described later) can be brought closer to the outer surface of the bar magnet 10, and the surface magnetic flux density of the bar magnet 10 can be increased.
In the container 12, a plurality of permanent magnets 14 and yokes 16 made of a magnetic material are alternately arranged to form a rod shape. Adjacent permanent magnets 14 are provided so that the same poles face each other and repel each other. The permanent magnet 14 has a coercive force of about 8
A magnet of 00 kA / m or more is used, and for example, an Nd-Fe-B-based rare earth magnet such as NEOMAX48BH manufactured by Sumitomo Special Metals Co., Ltd. is used. In addition, the permanent magnet 14 has N
It is desirable that a corrosion resistant coating such as i plating or Al coating is not formed. The outer diameter (diameter) of the permanent magnet 14 and the yoke 16 is 15 mm or more and 50 mm or less.

The thickness ratio of the yoke 16 to the permanent magnet 14 is set within the range of 1:20 to 6:20 (0.05 to 0.3). If the thickness ratio of the yoke 16 and the permanent magnet 14 is 1:20, that is, less than 0.05, the surface of the bar magnet 10 has a suction portion (area) corresponding to the strong suction force of the foreign matter. Can not do it. On the other hand, if the thickness ratio of both exceeds 6:20, that is, 0.3, the desired surface magnetic flux density cannot be obtained in the bar magnet 10. The thickness ratio of the yoke 16 to the permanent magnet 14 is 1:20 to 6:
By setting it within the range of 20 (0.05 to 0.3), it is possible to secure a sufficiently large attracting portion on the surface of the bar magnet 10 and also to obtain a desired surface magnetic flux density and thus a strong attracting force. It is possible to remove fine foreign matter more reliably.

Further, when the corrosion-resistant coating is not formed on the permanent magnet 14, the surface of the permanent magnet 14 can be brought closer to the surface of the bar magnet 10, and the surface magnetic flux density and the attractive force of the bar magnet 10 can be further increased. Further, in order to enclose the permanent magnet 14 and the yoke 16 in the container 12, sealing members 18 are attached to both ends of the container 12, respectively. The same material as the container 12 is used for the sealing member 18. This is because it is preferable to use a material having the same melting point and the same mechanical characteristics as the container 12 for the sealing member 18 in order to secure the bonding strength. The container 12 and the sealing member 18 are welded by TIG welding, for example.

A plurality of such bar magnets 10 are used to obtain a lattice type magnetic substance removing device 20 as shown in FIG. The magnetic substance removing device 20 includes, for example, a substantially square frame 22, and a plurality of bar magnets 10 are arranged in parallel in the frame 22.
At this time, for example, as shown in FIG. 9 described later, in adjacent bar magnets 10, the permanent magnets 14 included in one bar magnet 10 and the permanent magnets 14 included in the other bar magnet 10 are adjacent to each other.
And are arranged so that the opposite poles face each other. In this case, in adjacent bar magnets 10, the yokes 16 included in one bar magnet 10 and the yokes 16 included in the other bar magnet 10 are arranged so that their different poles face each other. Frame 2
2 and both ends of each bar magnet 10 are welded, for example, and both are integrated. Here, disposing the yokes 16 so that the different poles face each other means that the yokes 16 having different poles in the direction orthogonal to the longitudinal direction of the bar magnet 10 at least partially overlap each other. Say. In this way, the magnetic substance removing device 20 having a simple structure and being inexpensive and requiring no running cost can be obtained. The magnetic substance removing device 20 can more reliably remove fine foreign substances such as fine metal powder.

Next, an experimental example regarding the bar magnet 10 will be described. Here, a bar magnet 10 using a container 12 made of titanium alloy as shown in FIG. 3A and a bar magnet 10 using a container 12a made of stainless steel as shown in FIG. 3B.
With respect to a, the surface magnetic flux density distribution at the position corresponding to the yoke of the bar magnet was obtained when the thickness Lm of the permanent magnet 14 was kept constant and the thickness t of the yoke 16 was changed. The thickness Lm of the permanent magnet 14 is 10 mm, 15 mm, 2
The test was performed for each of 0 mm, 25 mm, and 30 mm, and the results shown in FIGS. 4 to 8 were obtained.

Here, the container 12 had a wall thickness of 0.3 mm and an outer diameter (diameter) of 24.1 mm, and the container 12a had a wall thickness of 0.75 mm and an outer diameter (diameter) of 25.0 mm. .
4 to 8, the surface magnetic flux density B at Lg = 0.3 mm is the surface magnetic flux density at a position 0.3 mm from the surface of the yoke 16 of the bar magnet 10, that is, at a position corresponding to the yoke on the outer surface of the bar magnet 10 (container 12). Represents Lg = 0.75 mm
The surface magnetic flux density B of the bar magnet 10a is 0.75 mm from the surface of the yoke 16 of the bar magnet 10a, that is, the bar magnet 10a (container 12
a) The surface magnetic flux density at the position corresponding to the yoke on the outer surface. Other experimental conditions include permanent magnet 14 with NEO.
MAX48BH, SS400 (JIS standard) is used for the yoke 16, and the outer diameter (diameter) of the permanent magnet 14 and the yoke 16 is set to 23.5 mm.

As shown in FIGS. 4 to 8, a bar magnet 10a (Lg = 0.75 m) using a stainless container 12a is used.
m), the surface magnetic flux density B is larger in the case of the bar magnet 10 (Lg = 0.3 mm) using the titanium alloy container 12, and the bar magnet 10 using the titanium alloy container 12 is larger. In this case, a surface magnetic flux density of 1.4T or higher could be obtained.

As another experimental example, a bar magnet 10 using a titanium alloy container 12 and a stainless steel container 12 are used.
The attraction force acting on the cubic iron powder having a size of 500 μm at a position 0.1 mm away from the surface of the bar magnet (container) was calculated by the finite element method for the bar magnet 10a using a. As the experimental conditions, in the case of the bar magnet 10, the thickness Lm of the permanent magnet 14 = 20 mm, the thickness t of the yoke 16 = 1.6 mm,
Outer diameter (diameter) of permanent magnet 14 and yoke 16 = 23.
It was 5 mm. In the case of the bar magnet 10a, the thickness Lm of the permanent magnet 14 = 20 mm, the thickness t of the yoke 16 = 2 mm, the outer diameter (diameter) of the permanent magnet 14 and the yoke 16 = 23.5.
It was mm.

As a result, the attraction force of the bar magnet 10a was 12 gr and the attraction force of the bar magnet 10 was 21 gr, and the attraction force of the bar magnet 10 using the titanium alloy container 12 was 1.75 times larger. Was obtained. From the above experimental results, the bar magnet 10 using the container 12 made of titanium alloy
According to the above, it is possible to obtain a surface magnetic flux density of 1.4 T or more, and it is possible to increase the suction force of foreign matter. Therefore,
For example, chips such as SUS304 and SUS316 and other fine metal powder having low magnetism can be collected, and the collection rate of foreign matters can be improved.

Further, another experimental example will be described. First, as shown in FIG. 9, the bar magnets 10 are arranged in parallel, and the yokes 16 included in one bar magnet 10 and the yokes 16 included in the other bar magnet 10 in the adjacent bar magnets 10 are arranged.
10 are arranged so that the different poles face each other, and the spatial magnetic flux density Bg distribution at that time is shown in FIG. Here, the position P1 shown in FIG. 9 is the origin of the X-axis in FIG. 10, and the direction that is intermediate between the adjacent bar magnets 10 and is parallel to the bar magnets 10 is shown in FIG.
It is 0 in the X-axis direction. Therefore, FIG. 10 shows the spatial magnetic flux density Bg distribution at the intermediate position between the adjacent bar magnets 10.

As an experimental condition, the permanent magnet 14 has a thickness L
NEOMAX48BH of m = 20 mm, yoke 16 is SS400 (JIS standard) of thickness t = 1.6 mm, container 1
2 is made of a titanium alloy having a thickness of 0.3 mm, the outer diameter (diameter) of the container 12 is 24.1 mm, the distance between the central axes of the adjacent bar magnets 50 is 50 mm, and the adjacent bar magnets 10 from the central axis of the bar magnets 10 are arranged. The distance to the intermediate position was 25 mm. The experimental conditions are the same in the experimental examples shown in FIGS. 11 and 12 described later.

In this experimental example, in adjacent bar magnets 10, the yokes 16 included in one bar magnet 10 and the yokes 16 included in the other bar magnet 10 are arranged so that their different poles face each other. A large suction force is generated between the opposing yokes 16. Therefore, the surface magnetic flux density in the vicinity of the yoke equivalent position of the bar magnet 10 increases. as a result,
As can be seen from FIGS. 9 and 10, the spatial magnetic flux density Bg
The absolute value of becomes maximum at the position corresponding to the yoke 16.

Next, as shown in FIG. 11, the bar magnet 10
Are arranged in parallel, and the yokes 16 included in one bar magnet 10 and the yokes 16 included in the other bar magnet 10 in the adjacent bar magnets 10 are arranged in a staggered arrangement, that is, with respect to the longitudinal direction of the bar magnets 10. They are arranged so that they do not partially overlap in the orthogonal direction, and the spatial magnetic flux density Bg at that time
The distribution is shown in FIG. Here, the position P2 shown in FIG. 11 is the origin of the X axis in FIG. As can be seen from FIGS. 11 and 12, the absolute value of the spatial magnetic flux density Bg corresponds to the portion where the yoke 16 included in one bar magnet 10 and the yoke 16 included in the other bar magnet 10 have opposite polarities. Maximum at position.

The spatial magnetic flux density B in the case where the yokes 16 are arranged so that the different poles face each other as shown in FIG. 10 is more than in the case where the yokes 16 are arranged in the zigzag arrangement shown in FIG.
The maximum value of g is increased, and the magnetic attraction force can be increased.
In the case shown in FIG. 12, the magnetic field attracting force is smaller than that in the case shown in FIG. 10, but a part having a spatial magnetic flux density Bg higher than a certain level is made wider without creating a part having an extremely low spatial magnetic flux density Bg. You can In addition, as shown in FIG. 13, the bar magnets 10 are arranged in parallel, and the yokes 1 included in one of the bar magnets 10 adjacent to each other are included.
6 and the yoke 16 included in the other bar magnet 10 may be arranged so that the same poles face each other.

The magnetic substance removing device 20 having the bar magnet 10 as described above can be applied to a food production line 30 as shown in FIG. 14, for example. The food production line 30 includes a hopper 32 in which food serving as raw material powder is stored. Hopper 3
2 is connected to a casing 36 via a pipe 34. The magnetic material removing device 20 is provided in the casing 36 in the horizontal direction, and a box 38 for performing the next process is provided at the outlet of the casing 36. Therefore, the hopper 3
The food in 2 is supplied to the casing 36 through the pipe 34, and after the magnetic substance removing device 20 removes metallic foreign matters such as iron powder in the casing 36, the food is supplied to the box 38. In this way, the fine magnetic substance can be removed from the food. The raw material powder capable of removing foreign substances such as iron powder by the magnetic substance removing device 20 is not only food but also rice grains, feed, feed, residues, pharmaceuticals, chemicals, synthetic resins, crushed waste, and the like. May be.

According to the magnetic substance removing device 20, the surface magnetic flux density of 1.4 T or more can be obtained, so that not only magnetic foreign substances such as iron powder but also foreign substances having low magnetism such as austenitic stainless steel can be removed. it can. Here, the magnetic material in the present invention includes a material having low magnetism such as austenitic stainless steel. The average particle size is about 100.
It is possible to remove magnetic foreign matter such as iron powder having an average particle size of approximately 50 μm or more and 500 μm or less, which has heretofore been difficult to remove from the raw material powder of μm or more and 3000 μm or less.

[0026]

According to the present invention, it is possible to obtain a bar magnet and a magnetic substance removing device which can remove fine foreign matter more reliably.

[Brief description of drawings]

FIG. 1 is a sectional view showing a bar magnet according to an embodiment of the present invention.

FIG. 2 is a perspective view showing a magnetic body removing device according to an embodiment of the present invention.

FIG. 3A is an illustrative view showing a bar magnet using a titanium alloy container, and FIG. 3B is an illustrative view showing a bar magnet using a stainless steel container.

FIG. 4A is a table showing an example of an experimental result when a permanent magnet having a thickness of 10 mm is used, and FIG. 4B is a graph thereof.

FIG. 5A is a table showing an example of an experimental result when a permanent magnet having a thickness of 15 mm is used, and FIG. 5B is a graph thereof.

FIG. 6A is a table showing an example of an experimental result when a permanent magnet having a thickness of 20 mm is used, and FIG. 6B is a graph thereof.

FIG. 7A is a table showing an example of an experimental result when a permanent magnet having a thickness of 25 mm is used, and FIG. 7B is a graph thereof.

FIG. 8A is a table showing an example of experimental results when a permanent magnet having a thickness of 30 mm is used, and FIG. 8B is a graph thereof.

FIG. 9 shows a state in which bar magnets are arranged in parallel, and in adjacent bar magnets, a yoke included in one bar magnet and a yoke included in the other bar magnet are arranged so that different poles face each other. It is an illustration figure.

10 is a graph showing a spatial magnetic flux density distribution when the yoke is arranged as shown in FIG.

FIG. 11 is a view in which bar magnets are arranged in parallel, and in adjacent bar magnets, a yoke included in one bar magnet and a yoke included in the other bar magnet are partially arranged in a direction orthogonal to a longitudinal direction of the bar magnets. It is an illustration figure which shows the state arrange | positioned so that it may not overlap.

FIG. 12 is a graph showing a spatial magnetic flux density distribution when the yoke is arranged as shown in FIG.

FIG. 13 shows a state in which bar magnets are arranged in parallel, and in adjacent bar magnets, a yoke included in one bar magnet and a yoke included in the other bar magnet are arranged so that the same poles face each other. It is an illustration figure.

FIG. 14 is an illustrative view showing an application example of a magnetic substance removing apparatus.

[Explanation of symbols] 10, 10a bar magnet 12, 12a container 14 permanent magnet 16 York 18 Sealing member 20 Magnetic substance removing device 30 food production line Lm Permanent magnet thickness t Yoke thickness

Continuation of front page (51) Int.Cl. ⁷ identification code FI theme code (reference) B03C 1/28 B01D 35/06 A (72) Inventor Junichi Sugaya 1-3-1 Kishibe, Suita, Osaka Inside Engineering Co., Ltd. (72) Inventor Tetsuro Dozaki 1-3-1 Kishibe, Suita City, Osaka Prefecture Sumitomo Engineering Co., Ltd.

Claims (7)

[Claims] 1. A cylindrical container, a plurality of rare earth magnets mounted in the container, and a yoke inserted in the container and interposed between the adjacent rare earth magnets, wherein the container is 0.1 mm or more 0 It is made of a titanium alloy having a thickness of 0.5 mm or less, and the rare earth magnets adjacent to each other are arranged so that the same poles face each other, and the thickness ratio of the yoke and the rare earth magnet is 1:20.
A bar magnet set at ~ 6: 20. 2. The bar magnet according to claim 1, wherein a corrosion resistant coating is not formed on the rare earth magnet. 3. A magnetic material removing device comprising a plurality of bar magnets according to claim 1. 4. The plurality of bar magnets are arranged in parallel, and in the adjacent bar magnets, the yokes included in one bar magnet and the yokes included in the other bar magnet have different polarities facing each other. The magnetic substance removing device according to claim 3, wherein the magnetic substance removing device is disposed in the. 5. The plurality of bar magnets are arranged in parallel, and in the adjacent bar magnets, the yoke included in one bar magnet and the yoke included in the other bar magnet are arranged in a longitudinal direction of the bar magnets. The magnetic substance removing device according to claim 3, wherein the magnetic substance removing device is arranged so as not to partially overlap with each other in a direction orthogonal to the magnetic substance removing device. 6. A plurality of bar magnets, each of which has a cylindrical container, a plurality of rare earth magnets mounted in the container, and a yoke which is mounted in the container and is interposed between the adjacent rare earth magnets, The magnetic substance removing device, wherein the yokes included in one of the bar magnets and the yokes included in the other bar magnet of the matching bar magnets are arranged so that their opposite poles face each other. 7. A plurality of bar magnets comprising: a cylindrical container; a plurality of rare earth magnets mounted in the container; and a yoke mounted in the container and interposed between the adjacent rare earth magnets, a plurality of bar magnets being provided. In the matching bar magnets, the yoke included in one bar magnet and the yoke included in the other bar magnet are arranged so as not to partially overlap with each other in a direction orthogonal to the longitudinal direction of the bar magnet. A magnetic substance removing device.