JP2012192304A - Rod-shaped magnet having inclined yoke arrangement structure and magnetic separator using the rod-shaped magnet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rod-shaped magnet that can eliminate or reduce a dead angle, allowing straight-through passage of magnetic foreign matter without magnetically attracting it, to obtain high magnetic attraction efficiency, requires an installation space at the same level as conventional ones, and can smoothly remove magnetic foreign matter attracted to the rod-shaped magnet.SOLUTION: In the rod-shaped magnet that includes magnet units and plate yokes alternately arranged in the longitudinal direction, the end surfaces of at least a part of the yokes in the longitudinal direction are inclined to a cross section perpendicular to the longitudinal direction.

Description

  The present invention relates to a bar magnet used for magnetically removing iron-based magnetic foreign matters mixed in various raw materials such as powders, granules, liquids, gases, fluids, products, and intermediate products. And a magnetic separation device provided with the rod-shaped magnet.

  In production lines for products such as resins, pigments, foods, medicines, spices, seasonings, feeds, fertilizers, etc., the raw materials used contain magnetic foreign substances such as iron powder, and screws used in the production lines Metal dust from equipment such as feeders and rotary valves, and magnetic foreign objects such as broken iron pieces are mixed into products and intermediate products.

Conventionally, it has been extremely important to prevent such magnetic foreign matters from being mixed and to ensure the safety of products and intermediate products, and the production line is provided with various magnets for magnetically removing magnetic foreign matters. .

  As such a magnetic foreign matter removing magnet, for example, Patent Document 1 (Japanese Patent Laid-Open No. 8-10642) discloses a short columnar magnet unit 82 and an electrode plate (plate yoke) as shown in FIGS. ) 83 are alternately arranged, and the center portion thereof is fixed by a connecting shaft 85 and the rod-shaped magnet 8 having a circular cross section enclosed by a tube 87 is described.

Further, as described in Patent Document 2 (Utility Model Registration No. 3164152) and as shown in FIGS. 9 and 10, a short column magnet 92 and a pole plate having a cross-sectional shape (pear shape) or teardrop type as shown in FIGS. The plate-shaped yokes 93 are alternately arranged, and the center portion thereof is fixed by a connecting shaft 95, and the teardrop-shaped rod-shaped magnet 9 encapsulated by a tube 97 is described.

This kind of bar magnets 8 and 9 is widely used in production lines for powdery products and intermediate products containing magnetic foreign matters, and for example, horizontally in a dropping path where a powdery workpiece is naturally dropped. It is expected to be removed by magnetic adhesion so that no magnetic foreign matter is left behind from the powder being dropped.

However, this kind of electrode plates (plate-shaped yokes) 83 and 93 are arranged in a direction perpendicular to the longitudinal axis of the bar-shaped magnets 8 and 9, and as shown in FIG. The magnetic force distribution along the longitudinal direction is the strongest at the portions of the plate-like yokes 83, 93, and the middle portion of the short cylindrical magnets 82, 92 sandwiched between the two plate-like yokes 83, 93 is the most. It is weak. Therefore, the following problems (a) and (b) became clear.
(A) The foreign matter adsorption width along the longitudinal direction of the rod-shaped magnets 8 and 9 is a narrow range of the plate-shaped yokes 83 and 93, and the magnetic foreign matter Q dropped on the intermediate portion having a weak magnetic force is shown in FIG. As shown, there is a problem that it moves downward along the intermediate part where the magnetic force is weak, and does not encounter the portions of the plate-like yokes 83 and 93 where the magnetic force is strong and may pass without being magnetized. is there.
(A) In this kind of rod-shaped magnets 8 and 9, when the magnetic foreign matter Q held magnetically is squeezed by sliding the foreign matter removing tool whose tip is perpendicular to the longitudinal axis to the outer peripheral surface, Since the magnetic foreign matter Q exists on the outer periphery of the plate-shaped yokes 83 and 93 which are strong portions, the driving force for moving the foreign matter removing tool is not constant, and a phenomenon such as stick-slip and vibrations accompanying it occur. There is also a problem that it may be difficult to smoothly remove the magnetic foreign matter Q.

  In addition, when the rod-shaped magnet 8 having a circular cross section shown in FIG. 7 is installed and used on the moving path of the powdery workpiece to be dropped due to gravity as shown in FIG. 8, the processing is continued. Then, the powdery object to be processed accumulates in a mountain shape on the upper surface side of the bar-shaped magnet, and the magnetic foreign matter Q contained in the subsequent object to be processed is separated from the slope of the mountain-shaped deposit without any magnetic force to the bar-shaped magnet 8 side. There is also a problem that it passes without being magnetized. However, it has been clarified by the present inventor that this problem can be solved by using the cross-sectional teardrop-shaped bar magnet shown in FIGS.

In order to solve the unsolved problems in these bar-shaped magnets 8 and 9, the present inventor has intensively studied, and regarding the problem (a), the bar-shaped magnets 8 and 9 are made of a powder-like workpiece. It has been found that the problem can be solved by providing an inclination in the falling path of natural falling. That is, when the bar-shaped magnets 8 and 9 are installed at an inclination, the magnetic foreign matter Q that has fallen on the intermediate portion having a weak magnetic force drops and moves on the outer peripheral surface in the direction of gravity. Therefore, the magnetic foreign matter Q can be prevented from passing through without being magnetized.

However, with the solution means in which the bar magnets 8 and 9 are installed at an inclination, the problem (A) cannot be solved. In addition, since this solution requires a larger processing space than when the bar magnets 8 and 9 are provided horizontally, it is difficult to apply to an existing magnetic foreign matter removing apparatus having no processing space. There is also a point. Furthermore, since a long bar-shaped magnet is required compared with the case where it is installed horizontally, there is a problem that the cost is increased.

Further, regarding the problem (a), the fluctuation of the driving force for sliding and moving the foreign substance removing tool is reduced by inclining the tip of the foreign substance removing tool with respect to the longitudinal axis, and there is a possibility that it can be solved. It was done. However, when the tip of the foreign material removing tool is inclined with respect to the longitudinal axis, on the other hand, a problem is required to completely remove the magnetic foreign material magnetically held on both ends of the bar magnets 8 and 9. It was also clear that dots would arise.

Japanese Patent Laid-Open No. 8-10642 Utility Model Registration No.3164152

The present invention is intended to solve the above-mentioned unsolved problems of the prior art, can widen the foreign matter adsorption width, and eliminates any blind spot through which magnetic foreign matters are not magnetized. Or, at least, the blind spot is reduced to increase the efficiency of magnetizing, and the installation space can be the same as that of the conventional one. Moreover, the magnetic foreign matter magnetized on the rod-shaped magnet can be removed smoothly. It is an object to provide a bar magnet.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that in a bar-shaped magnet including magnets and plate-shaped yokes alternately arranged in the longitudinal direction, at least some of the yokes in the longitudinal direction. It has been found that the above-mentioned problem can be solved by making the end surface an inclined surface inclined with respect to the cross section perpendicular to the longitudinal direction.

That is, the features of the present invention are as follows.
(1) A bar-shaped magnet including magnets and plate-shaped yokes alternately arranged in the longitudinal direction, and at least a part of the yoke end surfaces in the longitudinal direction are cross sections perpendicular to the longitudinal direction (hereinafter, A bar-shaped magnet having an inclined yoke arrangement structure characterized in that the inclined surface is inclined with respect to “a cross section perpendicular to the axis”.
(2) The inclined angle α of the inclined surface of the yoke with respect to the cross section perpendicular to the axis is within the range represented by the following formula (C). A bar-shaped magnet to play.
3M / 8L ≦ tan α ≦ 5M / 4L (C)
(However, L is a longitudinal section perpendicular to both the axis-perpendicular section and the inclined surface and includes a center of gravity of the section perpendicular to the axis (hereinafter, sometimes referred to as “longitudinal-axis section”). Represents the diameter of the rod-shaped magnet at, and M represents the length of the magnet alone excluding the magnet alone at both ends of the rod-shaped magnet.)
(3) The bar-shaped magnet having the inclined yoke arrangement structure according to (1) or (2), wherein the bar-shaped magnet has a symmetric shape with a cross section of the longitudinal axis as a symmetry plane.
(4) The yoke arrangement structure according to any one of (1) to (3), wherein all the yokes sandwiched between the magnets are inclined with respect to the cross section perpendicular to the axis. A bar-shaped magnet to play.
(5) The above-mentioned (1) to (4), wherein the cross-sectional shape perpendicular to the longitudinal axis of the bar-shaped magnet is a circle, an ellipse, a polygon, or a teardrop shape having the longitudinal axis cross-section as a symmetry plane. A bar-shaped magnet having the inclined yoke arrangement structure according to any one of the above.
(6) The magnet unit and the yoke are formed by screwing a male screw portion formed at an end portion of a connecting shaft that passes through a hole in the center portion of the magnet and a female screw of a tapped yoke or an end member. A bar magnet comprising the inclined yoke arrangement structure according to any one of (1) to (5) above, wherein the magnet is tightened.
(7) A magnetic separation apparatus in which a bar-shaped magnet having the inclined yoke arrangement structure according to any one of (1) to (6) is installed, and magnetically separates a magnetic body in a workpiece, The bar-shaped magnet is installed so that its longitudinal axis is substantially perpendicular to the moving direction of the workpiece and the longitudinal axis cross section is substantially parallel to the moving direction of the workpiece. Separation device.
(8) The rod-shaped magnet is of a teardrop-shaped cross section, and is installed on the moving path of the object to be processed while dropping due to gravity so that the arc portion of the teardrop-shaped cross section is vertically downward. The magnetic separator according to (7), characterized in that it is characterized in that

By having the above-described features, the present invention exhibits remarkable effects as described in the following (F) to (C).
(F) Since the rod-shaped magnet having the inclined yoke arrangement structure of the present invention can take a wide foreign matter adsorption width, there is no blind spot where a magnetic substance such as a magnetic foreign matter is not magnetically attached, or is as small as possible. It is possible to greatly improve the magnetic deposition efficiency.
(G) Since the bar-shaped magnet having the inclined yoke arrangement structure of the present invention can be installed in a direction perpendicular to the moving direction of the object to be processed, like the conventional bar-shaped magnet, the bar-shaped magnet is moved in the moving direction of the object to be processed. There is no need to increase the installation space as in the case of being provided with an inclination. Therefore, it is possible to greatly improve the magnetizing efficiency without significantly modifying an existing magnetic foreign matter removing apparatus.
(G) Since the length of the bar-shaped magnet can be shortened compared to the case where the bar-shaped magnet is provided to be inclined with respect to the moving direction of the workpiece, the manufacturing resources of the bar-shaped magnet can be saved.
(K) In the rod-shaped magnet having the inclined yoke arrangement structure of the present invention, since the plate-shaped yoke is inclined with respect to the longitudinal axis, the surface area of the plate-shaped yoke is increased, and the amount of adsorbed foreign matter is larger than that of the conventional rod-shaped magnet. Can be increased. Therefore, it is possible to reduce the number of operations for removing the magnetic foreign material that is intermittently performed on the bar magnet on which the magnetic foreign material is magnetically attached. In addition, the magnetic foreign matter held magnetically does not easily obstruct the flow of the workpiece, and the amount of the workpiece to be held in the magnetic foreign matter held magnetically can be significantly reduced. Furthermore, the magnetic foreign matter magnetically attached to the rod-shaped magnet can be removed smoothly. Therefore, coupled with the improvement of the magnetic adhesion efficiency as described above, the magnetic foreign matter removal efficiency and reliability can be greatly improved when used in the magnetic foreign matter removing apparatus.
(E) If the cross-section of the bar-shaped magnet having the inclined yoke arrangement structure of the present invention is a teardrop type, even if it is installed in the moving path of the powdery workpiece to be dropped due to gravity, The object to be processed hardly accumulates on the upper surface side, and the magnetic adhesion removal of the magnetic foreign matter is not hindered by the mountain-shaped powder having no magnetic force. Also, the magnetic force distribution on the outer peripheral surface along the yoke is weak at the top (mountain tip), strong at the bottom cylindrical portion, and medium at the mountain slope, so there is no magnetic field at the top or slope. The attached magnetic foreign matter is moved further downward from the lower slope portion, and most of the magnetic foreign matter is finally magnetically held on the cylindrical portion below the teardrop-shaped bar magnet. For this reason, there is almost no obstacle to the powder from which the magnetic foreign matter magnetically held on the rod-shaped magnet falls, and more magnetic foreign matter can be magnetically held, and it can be held in the magnetic foreign matter held magnetically. The amount of workpieces to be loaded can be further reduced.

It is drawing (sectional drawing in the plane containing the axis | shaft of a longitudinal direction) which shows the cross-section circular rod-shaped magnet which comprises the inclined yoke arrangement | sequence structure of 1st Example of this invention. It is drawing (sectional drawing in the plane containing the axis | shaft of a longitudinal direction) which shows the inclination of the inclination yoke in the rod-shaped magnet of 1st Example of this invention, and both ends of a magnet single-piece | unit. It is drawing which shows notionally the behavior of the magnetic foreign material in the outer peripheral surface of the rod-shaped magnet of 1st Example of this invention. It is drawing (sectional drawing in the plane containing the axis | shaft of a longitudinal direction) which shows the cross-sectional teardrop type | mold bar-shaped magnet which comprises the inclined yoke arrangement | sequence structure of 2nd Example of this invention. It is drawing which shows the outline shape of the cross section orthogonal to the axis | shaft of the cross-sectional teardrop type | mold bar-shaped magnet of 2nd Example of this invention. The drawing which shows the end part clamping structure of the bar-shaped magnet which comprises the inclination yoke arrangement | sequence structure of 3rd Example of this invention. (I) is a fragmentary sectional view in the plane containing the axis of a longitudinal direction, and (II) is an AA sectional view in (I). It is drawing (sectional drawing in the plane containing the axis | shaft of a longitudinal direction) which shows the conventional cross-section circular rod-shaped magnet. In the cross-sectional view perpendicular to the axis of a conventional circular rod-shaped magnet, it is a drawing conceptually showing the behavior of a magnetic foreign substance in a falling powdery workpiece. It is drawing (sectional drawing in the plane containing the axis | shaft of a longitudinal direction) which shows the conventional cross-sectional teardrop type | mold stick-shaped magnet. It is a cross-sectional view perpendicular to the axis of a conventional cross-sectional teardrop-shaped bar magnet. It is drawing which shows notionally the behavior of the magnetic foreign material in the outer peripheral surface of the conventional bar-shaped magnet.

The bar-shaped magnet having the inclined yoke arrangement structure of the present invention includes magnets and plate-like yokes arranged alternately in the longitudinal direction, and at least a part of the yoke end faces in the longitudinal direction. The inclined yoke is inclined with respect to a perpendicular plane (a cross section perpendicular to the axis).

  Even if some of the yokes are inclined, the foreign matter adsorption width can be widened partially, and the dead angle through which a magnetic substance such as a magnetic foreign matter is not magnetically attached can be partially reduced. Technically meaningful. Such an arrangement mode of the inclined yokes is not limited, but includes, for example, alternately arranging yokes perpendicular to the longitudinal direction (hereinafter, also referred to as “right angle yokes”) and inclined yokes. If all the yokes sandwiched between magnets are tilted yokes out of all the yokes of the bar magnet, the dead angle is such that a magnetic substance such as a magnetic foreign object passes through almost the entire length in the longitudinal direction of the bar magnet. It is most preferable because it can be eliminated or made as small as possible.

  The single magnet adjacent to the inclined yoke can be in close contact with the yoke with the end surface on the yoke side as an inclined surface having the same angle as the yoke. If a single magnet having inclined surfaces of the same angle on both sides is connected together with the inclined yoke, both end portions become inclined surfaces. When such a magnet and tilted yoke are integrated with a connecting shaft that communicates with the hole at the center thereof, a magnet with a trapezoidal or right-angled triangle cross section at both ends, or a trapezoidal or right-angled triangle end at the end By using the member, it is possible to make both ends easy to fix by making the surfaces perpendicular to the longitudinal direction. In the case where a single magnet having a trapezoidal cross section or a right triangle is used at both ends, a right angle yoke can be further disposed at both ends.

The inclination angle α with respect to the cross section perpendicular to the axis of the inclined yoke or the end face of the magnet is effectively expressed by the following formula (A) in order to effectively reduce the dead angle at which the magnetic foreign matter passes through without being magnetically attached. It is preferable (refer to the sectional view of the magnet unit 23 and the inclined yoke 31 in FIG. 2).
M / 4L ≦ tanα (A)
In the above formula, L represents a diameter of a rod-shaped magnet in a cross section (longitudinal axis cross section) in a longitudinal direction perpendicular to both the axis perpendicular cross section and the inclined surface, and including the center of gravity of the axis orthogonal cross section, M represents the length in the longitudinal direction of a single magnet excluding the single magnet at both ends of the bar-shaped magnet.
The length in the longitudinal direction of the intermediate magnet sandwiched between the magnets at both ends of the rod-shaped magnet is preferably uniform, but if the length is different, the length M in the longitudinal direction of the magnet alone is an average. Value. In addition, when the longitudinal axis section is a trapezoidal or triangular magnet alone, the length in the longitudinal direction of each magnet alone when obtaining the average value is the maximum value (the length of the base of the trapezoid or triangle) and the minimum value ( The length of the upper side of the trapezoid, which is the average of 0) for the triangle.

Even if the inclination angle α is increased by a predetermined value or more, the effect of eliminating the blind spot does not change so much, and if it is increased too much, it becomes difficult to manufacture the magnet alone. It is preferable to be represented by
tanα ≦ 3M / 2L (B)
A more preferable range and a more preferable range of the inclination angle α for eliminating or reducing the dead angle through which the magnetic foreign matter is not magnetized and making it as easy as possible and stopping the manufacture of the magnet alone are as follows: (C) and (D).
3M / 8L ≦ tan α ≦ 5M / 4L (C)
M / 2L ≦ tan α ≦ M / L (D)

  In order to make the foreign matter adsorption performance of the bar magnet uniform on both sides of the longitudinal axis cross section, the bar magnet is most preferably symmetrical with the longitudinal axis cross section as a symmetry plane. Even when the longitudinal cross section and the symmetry plane do not coincide with each other, if the angle between the longitudinal cross section and the longitudinal symmetry plane is within about ± 10 degrees (preferably within about ± 5 degrees), a certain degree of uniformity is obtained. Can hold. Further, such an angle range is preferable because the manufacture of the magnet alone is relatively easy.

Although a magnet single-piece | unit is not limited, For example, it consists of various permanent magnets, such as rare earth magnets, such as neodymium and samarium cobalt, a ferrite magnet, and an alnico magnet. The yoke is not limited, but can be formed from, for example, a SUS400 stainless steel plate. Further, the non-magnet end member is not limited, but can be formed of stainless steel such as SUS304, SUS316, or the like.

  The cross-sectional shape perpendicular to the axis of the rod-shaped magnet of the present invention is not limited, but may be, for example, a circle or a regular polygon (regular triangle, regular square, regular pentagon, regular hexagon, etc.), Alternatively, it may be an ellipse or a deformed polygon obtained by deforming a regular polygon in the horizontal direction or the vertical direction, or may be a composite shape formed by an arc portion and a straight portion.

When a rod-shaped magnet is installed in the middle of the fall of the workpiece containing magnetic foreign matter, the upper surface side has a mountain shape from the beginning when the cross section is a pair shape (pear shape) or teardrop type as described in Patent Document 2. Therefore, even if processing is continued, the processing object such as powder is hardly deposited on the upper surface side, and the magnetic adhesion removal of the magnetic foreign matter is not disturbed by the mountain-shaped powder having no magnetic force. Therefore, it is preferable.

Such a teardrop-shaped cross-sectional shape has two arcs and two arcs extending from the two ends of the arc in a substantially tangential direction and intersecting at an intersection on or near the axis of symmetry of the arc. And an inclined portion that substantially coincides with the straight line.

The arc portion is most preferably a part of an exact circle, but it may be a part of an ellipse, or a smooth uneven shape (exact The deviation from the circular arc may be, for example, within 20%, preferably within 10%, more preferably within 5% of the radius of the arc portion.

It is most desirable that the two inclined portions extending from both ends of the arc portion are linear straight portions. However, the entire inclined portion may have a mountain shape, and each inclined portion may have a concave shape with a slight deviation from the straight line. A convex shape, an uneven shape, or the like may be used. In that case, the depth of the concave or the like and the height of the convex or the like are acceptable, for example, within 20% (preferably within 10%, more preferably within 5%) of the radius of the arc portion.

The apex where the two inclined portions come into contact may be pointed as the intersection, but it is preferable to have an appropriate chamfered shape in the magnet manufacturing process. As the chamfered shape, although it depends on the size of the bar-shaped magnet, it is desirable to have a rounded chamfer of about 1 to 10 mm (preferably 2 to 5 mm).

Although the rod-shaped magnet having the inclined yoke arrangement structure of the present invention can be used without being encapsulated with a tube, it is desirable to encapsulate with a tube in order to prevent magnet powder from falling off or chipping of a magnet alone.

The application of the bar-shaped magnet having the inclined yoke arrangement structure is not limited, but is in the form of powder, granules, liquid, gas such as resin, pigment, food, medicine, spice, seasoning, feed, fertilizer, etc. In addition to various raw materials, products, intermediate products, etc., which can be used to remove magnetic adhesion of iron-based magnetic foreign matters mixed in the target, various liquids, powders, gases It can also be used for magnetic separation of fine magnetic products mixed in fluids.
The rod-shaped magnet having the inclined yoke arrangement structure of the present invention is most preferably installed at a right angle to the moving direction of the object to be processed in terms of installation space, but is inclined with respect to the horizontal (for example, about ± 20 degrees). Within about 10 degrees, preferably within about 10 degrees, and more preferably within about 5 degrees).
Further, in order to make the magnetic action uniform on both sides having the longitudinal cross section as a symmetrical plane, it is most preferable to provide the longitudinal cross section parallel to the moving direction of the object to be processed. It may be allowed to be installed inclined in the moving direction (for example, within about ± 20 degrees, preferably within about ± 10 degrees, more preferably within about ± 5 degrees).

  Hereinafter, the present invention will be described in more detail based on examples of the present invention with reference to the drawings. However, the present invention is not limited to these examples, and can be appropriately changed in design without departing from the gist of the present invention. Needless to say.

(First embodiment)
FIG. 1 shows a bar magnet 1 having a tilt yoke arrangement structure according to a first embodiment of the present invention. FIG. 1 is a longitudinal sectional view of the bar magnet. The cross section perpendicular to the axis of the bar-shaped magnet 1 has a circular shape similar to that of the conventional bar-shaped magnet shown in FIG.

  The bar magnet 1 includes magnets 2 and yokes 3 arranged alternately in the longitudinal direction. The individual magnets 2 are arranged so that the magnetic poles at the ends thereof are the same magnetic poles as the ends of adjacent magnets 2 with the plate-like yoke 3 interposed therebetween.

In this embodiment, all the yokes 3 except for the yokes 3 at both ends (that is, all the yokes 3 sandwiched between the magnets 2) are perpendicular to the longitudinal cross section and inclined with respect to the cross section perpendicular to the axis. The magnet unit 23 sandwiched between the inclined yokes 31 has inclined surfaces whose longitudinal end surfaces are inclined at the same angle (that is, opposite inclined sides of parallelograms in the longitudinal axis section). ). The single magnets 2 at both ends of the rod-shaped magnet 1 have a trapezoidal shape in which the cross-sectional shape in the plane of the longitudinal axis has one side perpendicular to the bottom side, but can also be a right triangle. Instead of using the right-angled yokes 31 and the trapezoidal magnet unit 25 at both ends, the end member 4 can also have a trapezoidal or triangular shape in the longitudinal axis cross-sectional shape.

The single magnet 2 and the plate-like yoke 3 are integrally assembled together with the end members 4 at both ends, and formed into the bar-like magnet 1. The means for such integration is not limited, but, for example, as shown in the embodiment of FIG. 1, the connecting shaft 5 that penetrates the hole in the center of the magnet unit 2 and the plate-like yoke 3. In addition, the connecting shaft 5 can be constituted by a female screw portion of the end member 4 that is screwed into a male screw portion 51 provided at both ends of the connecting shaft 5.

(Function)
The cross-sectional circular bar-shaped magnet 1 having the inclined yoke arrangement structure of the first embodiment of the present invention is perpendicular to the moving direction of the object to be processed on the moving path of the object to be processed including the magnetic foreign matter, and the inclined yoke. The operation in the case of configuring a magnetic foreign matter removing apparatus that installs a longitudinal cross section perpendicular to the moving direction in parallel to the moving direction and removes magnetic foreign matter in the workpiece will be described below with reference to FIG.

In the bar-shaped magnet 1 of the present invention, the longitudinal magnetic force distribution is the strongest at the yoke 3 portion as in the conventional bar-shaped magnet 8, and the longitudinal intermediate portion of the magnet unit 23 sandwiched between the two yokes 3. Is the weakest. However, in the rod-shaped magnet 1 of the present invention, the yoke 3 sandwiched between the magnets alone 2 (that is, the plate-like yokes 3 other than both ends) are all inclined yokes 31, so that the conventional rod-shaped magnet is used. 8, the region on the outer periphery of the bar-shaped magnet that has the strongest magnetic force in the longitudinal direction is shifted in the longitudinal direction along the inclination of the inclined yoke 31 as the workpiece moves in the moving direction. It intersects with the movement path of the foreign object Q. For this reason, even if the magnetic foreign matter Q dropped from above comes into contact with a portion having a weak magnetic force distribution in the longitudinal direction on the upstream side of the rod-shaped magnet 1 and tries to move without being magnetized, the magnetic force distribution in the longitudinal direction is strong during the movement. A part is encountered and magnetized, and the blind spot through which the magnetic foreign material is not magnetized can be eliminated. That is, the width of the foreign matter removal in the longitudinal direction based on one yoke of the conventional bar-shaped magnets 8 and 9 is approximately the same as the length K in the longitudinal direction of the yoke, whereas in one yoke of the bar-shaped magnet 1 of the present invention, The width of the foreign matter removal in the longitudinal direction can be as wide as about K + Ltanα (where L represents the diameter of the cross-sectional circular bar magnet, and α represents the angle of the inclined yoke with respect to the cross section perpendicular to the axis).
Further, since the magnetic foreign matter Q is magnetically held along the outer periphery of the yoke 3 having a strong magnetic force (that is, inclined with respect to the cross section perpendicular to the axis), the magnetic foreign matter Q is flown through the workpiece. It is unlikely to be an obstacle that stops even a part. Therefore, it is also clear that the bar-shaped magnet 1 of the present invention has an unexpected effect that the amount of workpieces to be held in the magnetic foreign matter Q held magnetically is significantly reduced as compared with the conventional bar-shaped magnet 8. became.

When the magnetic foreign matter Q magnetically held on the outer peripheral surface of the bar-shaped magnet 1 exceeds a predetermined amount, the foreign-matter removal operation for the workpiece is interrupted, and the foreign-matter removing tool is brought into sliding contact with the outer peripheral surface of the bar-shaped magnet 1. The magnetic foreign matter on the outer peripheral surface is removed with squeeze. At this time, since the magnetic foreign matter Q is magnetically held while being inclined with respect to the cross section perpendicular to the axis, when the foreign matter removing tool whose tip is perpendicular to the longitudinal axis is brought into sliding contact with the outer peripheral surface of the rod-shaped magnet, the tip There are one or two portions on the outer periphery of the bar-shaped magnet where the surface abuts at a time, and the contact portion moves in the circumferential direction of the outer periphery of the bar-shaped magnet in accordance with the sliding movement. Therefore, the driving force required to slidably contact the foreign matter removing tool and squeeze out the magnetic foreign matter does not fluctuate so much, and the foreign matter can be removed smoothly and efficiently without causing stick-slip phenomenon or vibration. .

(Second embodiment)
4 and 5 show a cross-sectional teardrop-shaped bar magnet 1 having an inclined yoke arrangement structure according to a second embodiment of the present invention. FIG. 4 is a longitudinal sectional view of the bar-shaped magnet, and FIG. 5 is a diagram showing the contour shape of the bar-shaped perpendicular section of the bar-shaped magnet.

The bar-shaped magnet 1 has a teardrop shape whose cross-sectional profile is as shown in FIG. 5, and the magnet unit 2, the yoke 3, and the end member 4 connected in the longitudinal direction also have a cross section perpendicular to the axis. The projection surface is teardrop-shaped. The single magnet 2, the yoke 3, and the end member 4 are arranged so that their cross-sectional teardrop shapes are aligned, and are tightened and integrated by appropriate integration means. In this embodiment, a male screw part 51 is provided at one end of the connecting shaft 5 penetrating through the central hole of the magnet 2 and the plate-like yoke 3 and screwed into the female screw part of one end member 4, With the other end of the connecting shaft 5 fitted in the hole of the other end member 4, the other end of the connecting shaft 5 and the hole of the other end member 4 are integrated into a welded portion W by welding. Yes.

In order to align the teardrop-shaped outer shape of the magnet alone 2, the plate-like yoke 3, and the other end member 4, the inner surface of the hole and the outer surface of the connecting shaft can be configured to be aligned. As such an alignment structure, various known modes such as a polygonal cross-sectional shape such as a hexagon and a key groove into which an alignment key can be inserted can be applied. If the flat portion is formed on the lower surface of the shaft portion 53 of the magnet 5, the volume of the magnet below the magnet unit 23 can be increased, and the magnetic force of the portion increases. Therefore, a more preferable magnetic force distribution along the outer periphery of the yoke Can be obtained.

In the second embodiment, the magnet single body 2, the plate-like yoke 3, and the end member 4 integrated by the connecting shaft 5 or the like are a protective tube 7 that prevents the magnet powder from dropping off or the magnet single piece from being chipped. Encapsulated with. The tube 7 can be formed from, for example, a metal sheet such as a stainless steel sheet or titanium sheet of SUS304 having a thickness of about 0.3 to 0.8 mm, a resin sheet, or the like.

Specifically, the contour shape of the cross-section perpendicular to the axis of the teardrop-shaped rod-shaped magnet of the second embodiment extends from the arc portion 12a and the two ends 12d of the arc portion 12a in substantially tangential directions, And a straight line portion 13a on two straight lines intersecting at an intersection 14a on or near the axis of symmetry 12c of the arc portion (see FIG. 5).

The straight line portion 13a extending from the end 12d of the contoured arc portion is most preferably in the tangential direction of the arc portion, but the angle of the straight line portion with respect to the tangential direction is ± 10 degrees, preferably ± 5 degrees. It can also be within the range. The angle β between the two straight portions is 20 to 80 degrees (preferably 30 to 70 degrees, more preferably 40 to 60 degrees), and the angle γ of the arc portion is 200 to 260 degrees (preferably 210 degrees). -250 degrees, more preferably 220-240 degrees). The two straight portions 13a are most preferably symmetric with respect to the symmetry axis 12c of the arc portion, but a slight deviation (for example, the distance from the intersection 14a to the symmetry axis 12c is the radius of the arc portion 12a). Within 10%, preferably within 5%). The intersection of the two straight portions is rounded or flattened to form a vertex 14b of the top portion 14. (When the top is chamfered flat, the point closest to the symmetry axis 12c in the flat portion is defined as the apex 14b.)

In the cross-sectional teardrop-shaped rod-shaped magnet 1 of the second embodiment, the magnetic force distribution along the yoke 3 on the outer peripheral surface is the weakest at the top portion 14 and gradually increases as the inclined surface portion 13 moves to the cylindrical portion 12 side. Since the cylindrical portion 12 is the strongest, the magnetic foreign matter magnetically attached in the middle of dropping continues to fall along the plate-like yoke 3 and accumulates in the cylindrical portion 12, particularly in the lower portion of the cylindrical portion 12. The attached magnetic foreign matter Q is magnetically held without being significantly affected by the flow of the workpiece.

(Function)
4 and 5, the teardrop-shaped rod-shaped magnet 1 of the second embodiment of the present invention is placed horizontally on the moving path of the powder-like workpiece to be dropped by gravity, and the top is vertically upward. The operation of the magnetic foreign matter removing apparatus configured to remove the magnetic foreign matter in the object to be processed will be described below with reference to FIG. 3 (in the second embodiment, the yoke 3 is the tube 7). 3 is slightly different from the first embodiment of FIG. 3 in that it is encapsulated in the case and is not exposed, and the inclination angle α of the yoke 3 is larger.

The cross-sectional teardrop-shaped bar-shaped magnet 1 of the second embodiment of the present invention, like the conventional cross-sectional teardrop-shaped bar-shaped magnet 9, has an upper surface formed in a mountain shape from the beginning, so that even if processing is continued, An object to be processed such as a body is hardly deposited on the upper surface side. Further, by setting the inclination angle of the mountain-shaped slope to be larger than the repose angle, powder accumulation can be prevented more reliably. Therefore, similarly to the conventional teardrop-shaped rod-shaped magnet 9, the removal of the magnetic foreign matter is not hindered by the mountain-shaped powder having no magnetic force.

The cross-sectional teardrop-shaped bar magnet 1 of the second embodiment has the strongest magnetic force distribution in the longitudinal direction at the portion of the plate-shaped yoke 3 as with the conventional cross-sectional teardrop-shaped bar magnet 9. 3, the intermediate part in the longitudinal direction of the short columnar magnet unit 23 sandwiched between 3 is the weakest. In addition, the magnetic force at the top is smaller than that of the cross-sectional circular bar magnet before the workpiece is deposited in a mountain shape on the upper surface side. However, in the cross-sectional teardrop-type bar magnet 1 of the second embodiment, since both longitudinal end surfaces of the magnet unit 23 are inclined surfaces and the plate-like yoke 3 is also inclined, a conventional cross-sectional teardrop-type bar magnet is provided. 9, the region on the outer periphery of the bar-shaped magnet, which has the strongest magnetic force in the longitudinal direction, shifts in the longitudinal direction along the inclination angle as it shifts from the top to the bottom, It is designed to intersect. For this reason, even if the magnetic foreign matter Q that has dropped from above falls to a portion where the magnetic force distribution in the longitudinal direction of the rod-shaped magnet top portion 14 is weak and attempts to slide down the peripheral surface of the rod-shaped magnet 1 without being magnetized, A portion where the magnetic force distribution in the direction is strong is encountered and magnetized. That is, the width of the foreign matter removal in the longitudinal direction based on one yoke in the conventional teardrop-shaped bar magnet is about the same as the longitudinal length K of the yoke, whereas the teardrop-shaped bar magnet 1 of the second embodiment. The width of the foreign matter removal in the longitudinal direction based on one yoke can be as wide as about K + Ltanα, and overlaps with the adjacent foreign matter removal width so that there is no blind spot through which the magnetic foreign matter is not magnetized. Further, the magnetic force distribution along the plate-like yoke 3 in the bar-shaped magnet 1 is the weakest at the top portion 14 as in the conventional teardrop-shaped bar-shaped magnet 9, and gradually increases as the inclined surface portion 13 moves to the cylindrical portion 12 side. Since the cylindrical portion 12 is the strongest, the magnetic foreign matter magnetized in the middle of dropping continues to fall along the plate-shaped yoke 3 and accumulates a lot in the cylindrical portion 12, particularly in the lower portion of the cylindrical portion 12, The magnetic foreign matter Q that has been magnetized is magnetically held without being significantly affected by the flow of the workpiece. Therefore, the amount of the object to be held in the magnetic foreign matter Q held magnetically is significantly reduced as compared with the conventional bar magnets 8 and 9, and compared with the cross-section circular bar magnet of the first embodiment. However, it is further reduced. Moreover, since the plate-shaped yoke is inclined with respect to the longitudinal axis, the surface area of the plate-shaped yoke is increased, and the amount of adsorbed foreign matter can be further increased as compared with the conventional teardrop-shaped type.

When the magnetic foreign matter Q magnetically held on the outer peripheral surface of the bar-shaped magnet 1 exceeds a predetermined amount, the foreign-matter removal operation for the workpiece is interrupted, and the foreign-matter removing tool is brought into sliding contact with the outer peripheral surface of the bar-shaped magnet 1. The magnetic foreign matter on the outer peripheral surface is removed with squeeze. The foreign matter removal operation from the outer peripheral surface at that time can be performed smoothly and efficiently as in the first embodiment.

In the above operation, the case where the cross-sectional teardrop-shaped bar magnet of the second embodiment is installed horizontally and the top portion is directed vertically upward with respect to the powder-like object to be naturally dropped has been described. It is not limited to such a to-be-processed object and an installation form. For example, when magnetically separating a magnetic substance contained therein from a liquid flowing in a flow path, the cross-sectional teardrop-shaped bar magnet of the present invention is perpendicular to the flow of the liquid and the top is upstream of the flow. By installing so that the cylindrical part is on the downstream side of the flow, the flow resistance can be reduced and, similarly to the above-mentioned action, the dead angle through which the magnetic foreign matter is not magnetized is eliminated or minimized. Can do.

(Third embodiment)
FIG. 6 shows an end clamping structure of a cross-sectional teardrop-shaped bar magnet having the inclined yoke arrangement structure of the third embodiment of the present invention. (I) is a fragmentary sectional view in the plane containing the axis of a longitudinal direction, and (II) is an AA sectional view in (I).

  In the first and second embodiments, in order to integrally tighten the magnet alone 2, the plate-like yoke 3, etc., the connecting shaft 5 penetrating through the central hole of the magnet alone 2, the plate-like yoke 3, and the connecting shaft 5 In the third embodiment, the end member 4 provided with a female screw part that is screwed into the male screw part 51 provided at the end of the end part is used. However, in the third embodiment, a tap is provided instead of the end member 4 provided with a female screw part. A yoke 33 is used.

In this kind of rod-shaped magnet 1, the magnetic poles at the longitudinal ends of each magnet unit 2 are arranged so as to be the same magnetic poles as the ends of adjacent magnet units 2 across the plate-like yoke 3 (FIG. 1). 4, 7, and 9), adjacent magnets 2 are subjected to forces in directions away from each other. In order to match the outer contours of the magnets 23 and 25, the yokes 31 and 32, and the like whose tear planes are projected onto the cross section perpendicular to the axis under the action of such a separating force, this third In the embodiment, the magnets 23 and 25 and the yokes 31 and 32 are alternately inserted into the tube 7 having the same inner surface shape as the outer contour. Since the single magnets 23 and 25 and the yokes 31 and 32 inserted alternately in the tube 7 are in a state in which the outer contours are aligned by the insertion, in this state, the connecting shaft that penetrates the hole in the center portion thereof. The male screw portion 51 of 5 and the female screw of the tapped yoke 33 are screwed together, and the tapped yoke 33 is tightened and integrated by rotating in the screwing direction. The tapped yoke 33 is provided with two rotation engagement holes 331 that engage with two protruding rods (not shown) of the rotation jig in order to perform the rotation. May not pass through the tapped yoke 33, or may be provided at three or more circumferentially at equal intervals, and a plurality of grooves extending in the radial direction may be formed instead of holes. May be. In short, any structure can be adopted as long as it can engage with the rotation jig and rotate the tapped yoke 33.

Such a tightening structure by the male screw portion 51 and the tapped yoke 33 is provided only at one end portion of the bar-shaped magnet 1, and the other end portion is, for example, a connecting shaft 5 as shown in FIG. Although it is good also as a fixed structure by the welding part W of the edge part of this and the hole part of the end member 4, when it provides in the both ends of a rod-shaped magnet, the freedom degree of a clamp | tightening integration work increases and it is preferable. Further, by providing the tapped yoke 33 at both ends separately from the right-angle yoke 32, it is possible to better prevent the magnetic force from escaping in an unfavorable direction, and the magnetic force on the outer surface of the rod-shaped magnet can be further increased. Is also preferable.

An end member 4 having a hole into which the distal end of the male screw 51 is inserted is attached to the end of the tube 7 at the longitudinal ends of the single magnets 23 and 25 and the yokes 31, 32, and 33 that are fastened and integrated in the tube 7. The end member 4 is inserted into the end portion, and the end member 4 is positioned at W (welded portion) in FIG. 6 (I) (that is, a contact portion between the outer peripheral portion of the end member 4 and the end portion of the tube 7, and At the contact portion or the proximity portion between the hole of the end member 4 and the outer periphery of the male screw portion 51, the tube 7 and the male screw portion 51 are joined by welding.

As described above, the rod-shaped magnet 1 having the inclined yoke arrangement structure of the third embodiment is firmly integrated by both screwing and welding using the tapped yoke 33, so that it can be used for a long time. In addition, it is possible to prevent a destruction accident due to the separation force between the magnets 2.
In the third embodiment, the tightening structure of the end portion of the bar-shaped magnet has been described by taking the cross-sectional teardrop-shaped bar-shaped magnet as an example, but the same applies to other cross-sectional shapes such as a circle, an ellipse, and a polygon. can do.

A magnetic separation device such as a bar magnet having the inclined yoke arrangement structure of the present invention or a magnetic foreign material removal device provided with the bar magnet is applied to any object that requires magnetic adhesion removal of the magnetic foreign material. It can also be applied to objects that require magnetic separation of magnetic products. Examples of such objects include powders, granules, liquids, gases, gas-liquid mixtures, suspensions, viscous fluids and the like containing magnetic foreign substances and magnetic products.

DESCRIPTION OF SYMBOLS 1 Bar magnet 12 which has inclined yoke arrangement | sequence structure Cylindrical part 12a (in axial orthogonal cross-sectional outline shape) Arc part 12b Arc point intermediate point 12c Arc part symmetrical axis 12d Arc part end 13 Slope part 13a (Axis right angle cross section Straight line part (inclined part)
14 vertex 14a intersection 14b vertex of extension line of two straight line parts

2 Magnet unit 21 Longitudinal end face (inclined face)
22 Longitudinal end face (Axial perpendicular face)
23 Magnet alone with both end faces inclined 25 Cross-section trapezoidal magnet alone

3 Yoke 31 Inclined yoke 32 Right angle yoke 33 Tapped yoke 331 Rotating engagement hole 4 End member 5 Connection shaft 51 Male thread portion 52 Fixed head portion 53 Shaft portion 7 Tube

8 Sectional bar magnet (conventional example)
82 Short cylindrical magnet unit 83 Plate-shaped yoke 84 End member 85 Connection shaft 87 Tube

9 Cross-section teardrop-shaped bar magnet (conventional example)
912 Cylindrical part 913 Slope part 914 Top part 92 Cross section teardrop type short column magnet simple substance 93 Plate-like yoke 94 End member 95 Connection shaft 97 Tube

α Angle of inclination of the yoke end surface with respect to the cross section perpendicular to the axis β Angle between the straight portions γ of the cross section of the cross section perpendicular to the axis K Angle of the arc section of the cross section of the cross section perpendicular to the axis K Length in the longitudinal direction of the yoke L Length of the bar magnet Diameter M in the shaft cross section Length P in the longitudinal direction of the magnet alone Powder object Q Magnetic foreign matter W Welded part

Claims (8)

  A bar-shaped magnet including magnets and plate-shaped yokes alternately arranged in the longitudinal direction, wherein at least a part of the yoke end surfaces in the longitudinal direction have a cross section perpendicular to the longitudinal direction (hereinafter referred to as “axis perpendicular”). A bar-shaped magnet having an inclined yoke arrangement structure characterized in that the inclined surface is inclined with respect to the cross section. 2. The bar-shaped magnet having the inclined yoke arrangement structure according to claim 1, wherein an inclination angle α of the inclined surface of the yoke with respect to a cross section perpendicular to the axis is within a range represented by the following expression (C).
3M / 8L ≦ tan α ≦ 5M / 4L (C)
(However, L is a longitudinal section perpendicular to both the axis-perpendicular section and the inclined surface and includes a bar-shaped magnet in a section including the center of gravity of the section perpendicular to the axis (hereinafter referred to as “longitudinal section”). M represents the length in the longitudinal direction of the single magnet excluding the single magnet at both ends of the rod-shaped magnet.)   The bar-shaped magnet having the inclined yoke arrangement structure according to claim 1 or 2, wherein the bar-shaped magnet has a symmetric shape with a cross section of the longitudinal axis as a symmetry plane. The bar-shaped magnet having the inclined yoke arrangement structure according to any one of claims 1 to 3, wherein all yokes sandwiched between the magnets are inclined with respect to a cross section perpendicular to the axis.   5. The cross-sectional shape perpendicular to the longitudinal axis of the rod-shaped magnet is a circle, an ellipse, a polygon, or a teardrop shape having the longitudinal cross-section as a symmetry plane. 6. A bar-shaped magnet comprising the inclined yoke arrangement structure described in 1.   The magnet alone and the yoke are tightened by screwing a male screw portion formed at an end portion of a connecting shaft passing through a hole in the center portion thereof and a tapped yoke or a female screw of an end member. A bar-shaped magnet comprising the inclined yoke arrangement structure according to any one of claims 1 to 5. A magnetic separator having magnetic poles in a workpiece to be magnetically separated, wherein the bar-shaped magnet having the inclined yoke arrangement structure according to any one of claims 1 to 6 is installed. A magnetic separation apparatus, characterized in that the longitudinal axis is set substantially at right angles to the moving direction of the workpiece, and the longitudinal axis cross section is substantially parallel to the moving direction of the workpiece. The bar-shaped magnet is of a teardrop-shaped cross section, and is installed in a moving path of an object to be processed in the middle of dropping due to gravity so that the arc portion of the cross-sectional teardrop type is vertically downward. The magnetic separator according to claim 7.