JP6729284B2 - Pin-through bond magnet, magnet structure, and method for manufacturing pin-through bond magnet - Google Patents

Description

The present invention relates to a pin penetration type bond magnet, a magnet structure using the pin penetration type bond magnet, and a manufacturing method for manufacturing the pin penetration type bond magnet.

In rotary motors, acoustic speakers, and the like that are equipped with permanent magnets, it is common to adhere and fix the permanent magnets to the housing using an adhesive (Patent Documents 1 and 2). For example, in a rotary motor, a plurality of segment-shaped (bow-shaped or semi-cylindrical) permanent magnets are fixed to the outer periphery of a stator core with an adhesive. The reason for using the adhesive in this way is that the permanent magnet is a functional member for generating a magnetic force, and is not a structural member that can be mechanically fastened with a screw, a holding plate or the like.

The adhesive strength of an adhesive depends on various factors such as the adhesive strength of the adhesive itself, the adhesive area, how to spread the adhesive, the distance between both adherends, the surface roughness of the adhesive surface, and the wettability. Change significantly. Therefore, in consideration of the variation in the adhesive force thus generated, for example, the adhesive area is assumed to be about 1/3 of the actual total contact area, or the safety factor is set to be three times or more higher.

Despite these measures, if the adhesive was not sufficiently cured or the adhesive changed over time, the adhesive was fixed due to the effects of magnetic repulsion and rotational centrifugal force. The permanent magnet may peel off and scatter.

Therefore, a method of fixing segment-shaped or ring-shaped permanent magnets without using an adhesive has been proposed (Patent Documents 3 and 4). In Patent Document 3, a permanent magnet holding member made of synthetic resin that is fixedly provided on the outer peripheral portion of the rotor body is used, and a permanent magnet is provided between adjacent rod-shaped claw portions extending in the axial direction of the permanent magnet holding member. Is inserted and both outer edge portions of the permanent magnet are held and fixed by the claw portions of the rod-shaped portion. In Patent Document 4, a disk-shaped yoke material having a shaft hole in the center is attached to both open end portions of a cylindrical body made of a composite magnet, and a shaft is inserted into the shaft hole to be integrally assembled.

JP, 2004-236366, A JP, 2002-58183, A JP, 2010-207075, A JP-A-3-124237

With the increase in magnetic force of permanent magnets, their shapes are becoming lighter, thinner and smaller. Therefore, in a thin segment-shaped permanent magnet, it is difficult to hold and fix only the outer edge portion other than the magnetic pole surface as described in Patent Document 3. This is because, in the case of holding and fixing only the outer edge portion, stress concentration such as bending and twisting occurs in the fixed permanent magnet, and the permanent magnet is damaged. In the configuration of Patent Document 4, since the composite magnet, the yoke material, and the shaft are integrally assembled and fixed, stress concentration such as bending or twisting occurs in the fixed composite magnet, as in Patent Document 3. The composite magnet will be damaged.

The present invention has been made in view of such circumstances, and can be firmly fixed even in a harsh environment, without using an adhesive, in spite of a light, thin, short, and small segment shape or a ring shape. An object of the present invention is to provide a pin-through bond magnet, a magnet structure using the pin-through bond magnet, and a manufacturing method for manufacturing the pin-through bond magnet.

The pin-penetrating bond magnet according to the present invention includes a segment-shaped or ring-shaped bond magnet main body, and a plurality of pins integrally penetrating the bond magnet main body in such a manner that both ends project from the bond magnet main body. It is characterized by including.

In the pin-through type bonded magnet of the present invention, a plurality of pins are integrally penetrated through a segment-shaped (for example, bow-shaped or semi-cylindrical) or ring-shaped bonded magnet body, and both ends of the pin are bonded. It projects from the magnet body. The fastening force between the bonded magnet body and the pin is evenly distributed over the entire magnet without stress concentration on the contact surfaces. Therefore, the bonded magnet body is not damaged. It is possible to obtain a desired fastening force by adjusting the thickness and the number of the penetrating pins.

The pin-through type bonded magnet according to the present invention is characterized in that the volume of the pin is 10% or less of the whole.

In the pin-through type bonded magnet of the present invention, the volume of the pin is 10% or less of the volume of the entire magnet. Therefore, the deterioration of the magnetic characteristics due to the provision of the pin can be suppressed.

The pin-penetrating bond magnet according to the present invention is characterized in that a recess is formed in the center of the pin.

In the pin-through type bonded magnet of the present invention, a recess is formed in the central portion in the longitudinal direction of the pin. Therefore, the pin is prevented from coming off the bonded magnet body.

The pin-through type bonded magnet according to the present invention is characterized in that the bonded magnet body contains a magnetic powder of an RTB-based alloy and a thermosetting resin.

In the pin-through type bonded magnet of the present invention, the bonded magnet body is made of a kneaded product of the magnetic powder of the RTB-based alloy and the thermosetting resin so as to be suitable for compression molding.

A magnet structure according to the present invention has a single or a plurality of pin-penetrating bond magnets as described above and a plurality of holes into which one end of each pin of the single or a plurality of pin-penetrating bond magnets is fitted. And a yoke body.

The magnet structure of the present invention is configured by fitting one end of each pin of the pin penetration type bond magnet into the hole of the corresponding yoke body. Therefore, the pin-penetrating bond magnet is mechanically and firmly fastened to the yoke body without using an adhesive.

The method for manufacturing a pin-through type bonded magnet according to the present invention uses a compression molding apparatus having an upper punch, a lower punch and a die to project both ends of a segment-shaped or ring-shaped bonded magnet main body to form a plurality of pins. A method of manufacturing a pin-penetrating bond magnet, which integrally penetrates a pin-penetrating bond magnet, wherein an upper punch hole for inserting a pin is provided in the upper punch, and a pin punch is formed in the lower punch. A lower punch concave portion for accommodating one end portion is provided, a step of preparing a kneaded product of magnetic powder and a thermosetting resin, a step of arranging a pin in the lower punch concave portion, and a step of lowering the lower punch. The step of forming a cavity between the die and the lower punch, the step of filling the formed kneaded product in the formed cavity, and the step of raising the pin to move the pin. And a step of inserting a part thereof into the upper punch hole, and a step of lowering the upper punch and/or raising the lower punch to compress the kneaded material filled in the cavity. Is characterized by.

In the method of manufacturing a pin-through type bonded magnet according to the present invention, after the pins are arranged in the recesses of the lower punch, the magnetic powder and the heat are introduced into the cavity between the die formed by lowering the lower punch and the lower punch. After filling the kneaded product with the curable resin and raising the pin to insert a part thereof into the upper punch hole, the upper punch is lowered and/or the lower punch is raised to compress the kneaded substance. Therefore, it is possible to accurately manufacture the above-described pin-penetrating bond magnet containing the thermosetting resin as the binder.

ADVANTAGE OF THE INVENTION According to the present invention, it can be firmly fixed without the use of an adhesive, and despite its light, thin, short, and small segment shape (bow shape or kamaboko shape) or ring shape, it is a pin penetration type that is difficult to peel off even in a harsh environment. A bond magnet can be provided.

Further, according to the present invention, it is possible to provide a magnet structure in which the bonded magnet and the yoke body are firmly fastened without using an adhesive.

Further, according to the present invention, it is possible to provide a method of manufacturing a pin-penetrating bond magnet that can accurately manufacture the above-described pin-penetrating bond magnet.

It is a perspective view showing the composition of the pin penetration type bond magnet concerning the present invention. It is a sectional view showing composition of a pin penetration type bond magnet concerning the present invention. It is a perspective view which shows the shape of a pin. It is a figure which shows the process of the manufacturing method of the pin penetration type|mold bond magnet by a compression molding method. It is a figure which shows the process of the manufacturing method of the pin penetration type|mold bond magnet by a compression molding method. It is a figure showing a manufacturing method of a pin penetration type bond magnet by an injection molding method. It is a perspective view showing an example of a magnet structure concerning the present invention. It is an exploded view showing an example of a magnet structure concerning the present invention. It is a perspective view which shows the other example of the magnet structure which concerns on this invention. It is an exploded view showing other examples of a magnet structure concerning the present invention. It is a perspective view which shows the further another example of the magnet structure which concerns on this invention. It is an exploded view showing further another example of a magnet structure concerning the present invention.

Hereinafter, the present invention will be described in detail with reference to the drawings showing an embodiment thereof.

1 and 2 are a perspective view and a cross-sectional view showing the structure of a pin-through type bonded magnet according to the present invention. The pin-through bond magnet 1 is composed of a bond magnet body 11 and two pins 12.

The bonded magnet body 11 has a light, thin, short, and small bow shape as a whole. For example, the thickness t thereof is 1.5 mm to 5 mm, and the circumferential length L thereof is 30 mm to 50 mm. Has a length of about 40 mm. The bonded magnet body 11 is formed by curing a kneaded material of magnetic powder and resin (binder). The details of the magnetic powder and the resin material used will be described later.

Two pins 12, 12 are integrally provided with the bond magnet main body 11 at positions symmetrical with respect to the circumferential direction of the bond magnet main body 11 so as to penetrate the bond magnet main body 11 in the longitudinal direction thereof. Both ends (one end 12 a, the other end 12 b) of each pin 12 project from the bonded magnet body 11.

FIG. 3 is a perspective view showing the shape of the pin 12. The pin 12 may be either a magnetic pin or a non-magnetic pin, but it is preferable to use non-magnetic hardened steel, for example, SUS420J2 which is stainless steel. By using hardened steel as the pin 12, the strength of the entire bonded magnet is increased. The pin 12 has a long columnar shape (diameter d: 0.5 mm to 2 mm, length L': about 50 mm). A recess 12c is formed in the central portion in the longitudinal direction of the pin 12 over the entire area or a partial area in the circumferential direction, so that the pin 12 in the pin-through bond magnet 1 is prevented from coming off. The contact surface of the pin 12 with the bond magnet body 11 may be subjected to processing such as knurling or blasting in order to increase the degree of coupling. Further, the shape of the contact surface of the pin 12 may be a polygonal column such as a square column or an elliptic column.

The magnetic powder used for the bonded magnet body 11 will be described. As the magnetic powder, an RTB-based alloy is used. R-T-B type alloy, compound phase R ₂ T ₁₄ B-type is an alloy which account for more than 50 vol% as the main phase. R is a rare earth element and contains at least one of Nd (neodymium) and Pr (praseodymium).

The content of R in the RTB-based alloy is preferably 23% by mass or more and 40% by mass or less, and more preferably 26% by mass or more and 34% by mass or less in mass%. If the content of R is less than 23% by mass, the coercive force of the R-T-B type alloy will decrease. On the other hand, when the content of R exceeds 40 mass %, the ratio of the main phase (R ₂ T ₁₄ B type compound phase) decreases, and the magnetization of the RTB-based alloy decreases.

T is an iron group element, and corresponds to Fe (iron), Co (cobalt), and Ni (nickel). In addition, when Co is added instead of Fe, the Curie point of the RTB-based alloy rises, the magnetic anisotropy of the RTB-based alloy is more easily obtained, and high magnetization is obtained. To be In addition, in order to suppress the decrease in the magnetization of the RTB-based alloy, the addition of Co is preferably 50 mass% or less of T. Further, when a small amount of Ni is added instead of Fe, the magnetic anisotropy of the RTB-based alloy is more easily obtained, and high magnetization is obtained. In addition, in order to suppress the decrease in the magnetization of the RTB-based alloy, the addition of Ni is preferably 5% by mass or less of T.

Further, the content of T in the R-T-B alloy is preferably 57% by mass or more and 76% by mass or less in mass%. When the content of T is less than 57% by mass, the ratio of the main phase is decreased and the magnetization is reduced. On the other hand, when the content of T exceeds 76 mass %, a magnetically soft phase is generated in the R-T-B type alloy, and the coercive force of the R-T-B type alloy decreases.

B (boron) may be partially or completely substituted with C (carbon). The content of B in the RTB-based alloy is preferably 0.6% by mass or more and 1.6% by mass or less in mass%. If the B content is less than 0.6% by mass, a magnetically soft phase is generated in the RTB-based alloy, and the coercive force of the RTB-based alloy is reduced. On the other hand, when the content of B exceeds 1.6 mass %, the ratio of the main phase decreases, and the magnetization of the RTB-based alloy becomes small.

Further, in order to improve magnetic anisotropy or coercive force, other elements may be added to the R-T-B type alloy as needed. Examples of the additive element effective in improving the magnetic anisotropy include Ga (gallium), Zr (zirconium) and Hf (hafnium). Moreover, Cu (copper), Al (aluminum), and the like are added elements effective in improving the coercive force. In addition, if necessary, Si (silicon), Ti (titanium), V (vanadium), Cr (chromium), Mn (manganese), Zn (zinc), Ge (germanium), Nb (niobium), In (Indium), Sn (tin), Ta (tantalum), W (tungsten), Pb (lead), etc. may be added to the RTB-based alloy.

The additive elements can be added alone or in combination of two or more. The additive amount of the additional element in the RTB-based alloy is preferably 7.6 mass% or less (or 5 at% or less) when added for the purpose of the above effect. When the amount of the additional element added to the RTB-based alloy exceeds 7.6 mass %, the ratio of the main phase decreases, and the magnetization of the RTB-based alloy decreases.

Next, the resin used as the binder (binder) that is used in the bonded magnet body 11 and solidifies the magnetic powder (RTB-based alloy) as described above will be described. The type of resin is appropriately selected according to the manufacturing method (compression molding method, injection molding method, extrusion molding method, sheet molding method) of the pin penetration type bond magnet 1.

That is, when the pin-through type bonded magnet 1 is manufactured by compression molding, a thermosetting resin such as an epoxy resin is used. At this time, the content of the thermosetting resin in the bonded magnet main body 11 is preferably 1% by mass or more in order to suppress the decrease in the degree of bonding between the RTB-based alloy and the pin. Further, in order to suppress the decrease in the magnetic energy of the pin penetration type bond magnet 1, the content of the thermosetting resin is preferably 2.5% by mass or less.

When manufacturing the pin penetration type bonded magnet 1 by injection molding, a thermoplastic resin such as a polyamide resin or a polyphenylene sulfide resin (PPS) is used. When the pin-penetrating bond magnet 1 is manufactured by extrusion molding, a thermoplastic resin such as polyamide resin or thermoplastic elastomer is used. When the pin penetration type bond magnet 1 is manufactured by sheet molding, a thermoplastic resin such as a thermoplastic elastomer is used. In order to suppress deterioration of magnetic properties, the content of the thermoplastic resin (in the case of injection molding, extrusion molding and sheet molding) in the bonded magnet body 11 is preferably 50% by mass or less. The content of the thermoplastic resin is preferably 40% by mass or more in order to suppress the decrease in the degree of bonding between the RTB-based alloy and the pin.

Hereinafter, a method of manufacturing the pin penetration type bonded magnet 1 will be described. First, an example of manufacturing the pin penetration type bonded magnet 1 by the compression molding method will be described.

First, magnetic powder for a bonded magnet is produced. After melting the RTB-based alloy having a predetermined composition, the RTB-based alloy is thinned by a super-quenching method (jet casting, strip casting, or the like). Then, the thinned RTB-based alloy is pulverized by a pulverizer so as to have a predetermined particle size. A heat treatment for determining the magnetic properties is performed to obtain a magnetic powder composed of an RTB-based alloy. The magnetic powder thus obtained is mixed with a thermosetting resin (e.g., epoxy resin) as a binder (binder) using a kneader to prepare a magnetic powder for a bonded magnet. The particle size of the magnetic powder for bonded magnets is preferably 50 μm to 200 μm, more preferably 50 μm to 150 μm in terms of 50% mass particle size determined by classification with a sieve. With the above-mentioned particle size of the magnetic powder for the bonded magnet, the plurality of pins can be filled in the cavity, which will be described later, in which a plurality of pins are arranged without being pushed down even if the pins are pushed by a feeder. Further, the magnetic powder for the bonded magnet does not get caught between the pin and the concave portion on the surface of the punch in the molding process. Furthermore, the pin and the bond magnet can be firmly connected by filling the pin surface (particularly the pin recess) without gaps during press molding.

Prepare pin 12. A non-magnetic wire material such as stainless steel is cut into a predetermined size to obtain two pins 12. A recess 12c is formed in the center of each pin 12 by polishing, acid treatment, or the like. In order to increase the degree of coupling between the bond magnet body 11 and the contact surface of the pin 12, the depth of the recess 12c is preferably 100 μm to 500 μm. Further, it is preferable that the contact surface of the pin 12 is subjected to processing such as knurling and blasting in order to increase the degree of bonding. Further, the shape of the contact surface of the pin 12 may be a polygonal column such as a square column or an elliptic column.

Prepare a compression molding device for use in the compression molding method. FIG. 4 and FIG. 5 are diagrams showing steps of a method of manufacturing the pin penetration type bonded magnet 1 by the compression molding method.

FIG. 4A shows the configuration of the compression molding apparatus, and the compression molding apparatus includes a cylindrical die 21, an upper punch 22, and a lower punch 23. On the molding surface of the upper punch 22, two upper punch holes 22a are formed which extend a proper length in the longitudinal direction. The pin 12 is inserted into the upper punch hole 22a as described later, and the length of the upper punch hole 22a is such that the pin 12 and the upper punch 22 do not interfere with each other during compression molding. The upper punch hole 22a is provided with a taper 22b so that the molding surface side expands. This taper angle is required to be 3 to 10 degrees with respect to the side surface of the upper punch hole 22a extending to the forming surface of the upper punch 22, but this depends on the die assembling accuracy of the compression forming apparatus. The ratio of the upper punch hole 22a to the upper punch forming surface is preferably 1% or more and 10% or less. When it exceeds 10%, the strength of the compression-molded bond magnet is increased due to the presence of the pin 12, but the occupancy of the non-magnetic pin 12 is increased, which may deteriorate the characteristics of the bond magnet.

On the other hand, on the molding surface of the lower punch 23, two lower punch recesses 23a having a predetermined depth are formed, and the end portions of the pins 12 are housed in the lower punch recesses 23a as described later. The bottom of the lower punch recess 23a can be raised and lowered independently of the lower punch 23.

As shown in FIG. 4B, one end of each of the two pins 12 is housed in the lower punch recess 23a of the lower punch 23, and the two pins 12 are arranged on the molding surface of the lower punch 23 of the compression molding apparatus. At this time, the position of the pin 12 is adjusted so that the pin 12 can be inserted into the upper punch hole 22a. As shown in FIG. 4C, the lower punch 23 is lowered to form a cavity 24 between the die 21 and the lower punch 23.

Next, as shown in FIG. 5A, the formed cavity 24 is filled with the prepared magnetic powder 25 for bonded magnet, which is a kneaded product of magnetic powder and thermosetting resin. The filling method is not particularly limited, but in order to perform uniform filling, the raw material powder is supplied to the feeder body that moves forward and backward with the opening on the lower surface and the raw material powder supply pipe connected to the upper or rear supply pipe connection opening. The feeder main body is advanced on the die to fill the raw material powder into the opening hole formed in the die, and then is retracted, which is a feeder in the powder molding apparatus (for example, Japanese Patent Laid-Open No. 9-327798). , JP-A-10-118794, JP-A-2010-240697, etc.) are preferably used. After the filling, as shown in FIG. 5B, only the pin 12 is raised to an appropriate length. As shown in FIGS. 5C and 5D, the upper punch 22 is lowered, and the pins 12 are inserted into the upper punch holes 22a to compress the bond magnet magnetic particles 25 to a predetermined density. Although the upper punch 22 is lowered to compress the bond magnet magnetic powder 25, the lower punch 23 may be raised to compress the bond magnet magnetic powder 25, or the upper punch 22 is lowered and lowered. The punch 23 may be moved up at the same time to compress the bonded magnet magnetic powder 25.

Next, the upper punch 22 and the lower punch 23 are raised while holding the pin-penetrating bond magnet 1 in which the pins 12 are integrated. The pin-penetrating bond magnet 1 is taken out to the surface of the die 21, the upper punch 22 is further raised, and then the manufactured pin-penetrating bond magnet 1 is taken out. The taken out pin-through bond magnet 1 is heat-treated. The heat treatment temperature is preferably in the range of 150° C. to 400° C., and the heat treatment time is preferably 1 minute to 4 hours.

Next, an example of manufacturing the pin penetration type bonded magnet 1 by the injection molding method will be described.

First, magnetic powder for a bonded magnet is produced. After melting the RTB-based alloy having a predetermined composition, the RTB-based alloy is thinned by a super-quenching method (jet casting, strip casting, or the like). Then, the thinned RTB-based alloy is pulverized by a pulverizer so as to have a predetermined particle size (preferably about 100 μm). A heat treatment for determining the magnetic properties is performed to obtain a magnetic powder composed of an RTB-based alloy. A pellet for a bonded magnet is produced by mixing the obtained magnetic powder and a thermoplastic resin (for example, polyamide resin) as a binder using a kneader.

Prepare pin 12. A non-magnetic wire material such as stainless steel is cut into a predetermined size to obtain two pins 12. A recess 12c is formed in the center of each pin 12 by polishing, acid treatment, or the like.

Prepare an injection molding device for use in injection molding. FIG. 6 is a diagram showing a method of manufacturing a pin penetration type bonded magnet by an injection molding method. The injection molding device includes a pair of manufactured split molds 31, 31 and a gate 32.

After opening one split mold 31 and installing the two pins 12, the split mold 31 is closed to form a cavity 33. The produced bond magnet pellet is melted by heat, and the melted raw material is poured into the cavity 33 through the gate 32. After flowing the raw material into the cavity 33, wait until the raw material cools and solidifies. In addition, the split mold 31 is heated or cooled as necessary in order to prevent sink marks of the molded body. After cutting the gate 32, both split molds 31 are opened, and the pin-penetrating bond magnet 1 in which the pins 12 are integrated is taken out.

Hereinafter, a magnet structure using the pin penetration type bond magnet 1 will be described. 7 and 8 are a perspective view and an exploded view showing an example of the magnet structure according to the present invention.

In this magnet structure 2, eight pin-penetrating bond magnets 1 each having a segment shape as described above are arranged in a circle, and one end 12a of each pin 12 has an annular yoke material. The pin 12 is fitted in the corresponding hole 42, and the other end 12b of each pin 12 is fitted in the corresponding hole 44 of the bottomed cylindrical container 43.

9 and 10 are a perspective view and an exploded view showing another example of the magnet structure according to the present invention. In this magnet structure 3, eight pin-penetrating bond magnets 1 each having a segment shape as described above are arranged in a circle, and one end 12a of each pin 12 has an upper annular shape. The yoke member 45 is fitted in the corresponding hole 46, and the other end 12b of each pin 12 is fitted in the corresponding hole 48 of the lower annular yoke member 47. In this example, the circular arrangement of a plurality of pin-penetrating bond magnets 1 is provided in only one stage, but the circular arrangement may be provided in a plurality of stages via the yoke material.

11 and 12 are a perspective view and an exploded view showing still another example of the magnet structure according to the present invention. This magnet structure 4 has a different number of holes from the examples of FIGS. 9 and 10, but one end of each pin 12 in one ring-shaped pin-penetrating bond magnet 1 having eight pins 12. The portion 12a is fitted in the corresponding hole 42 of the annular yoke material 41, and the other end 12b of each pin 12 is fitted in the corresponding hole 44 of the bottomed cylindrical container 43. Have Such a ring-shaped pin-penetrating bond magnet 1 is integrally molded in advance in a ring shape and is suitable for a relatively small motor using a bond magnet having a magnet inner diameter of 10 mm to 100 mm. Further, when the magnet is thick, a magnetic pin (for example, an iron pin) may be used as the pin 12 in consideration of the demagnetization of the magnet and the amount of magnetic flux.

Although illustration is omitted, similar to the example of FIGS. 9 and 10, although the number of holes is different, each pin 12 in one ring-shaped pin through bond magnet 1 having eight pins 12. One end 12a of the pin 12 is fitted into the corresponding hole 46 of the upper yoke material 45, and the other end 12b of each pin 12 is fitted into the corresponding hole 48 of the lower yoke material 47 of the lower ring. They may be fitted together to form a magnet structure.

In such a magnet structure 2, 3 or 4, an armature is arranged in an internal space surrounded by a plurality or a single pin-penetrating bond magnet 1 to form a magnet motor. On the contrary, an armature may be provided on the outer side of the annular arrangement of the plurality or the single pin penetration type bond magnets 1.

In the above-described embodiment, one segment-shaped pin-penetrating bond magnet 1 has two pins 12, and one ring-shaped pin-penetrating bond magnet 1 has eight pins 12. Although the structure having the above has been described, the number of pins 12 provided in one segment-shaped pin-through bond magnet 1 may be three or more, and one segment-shaped pin-through bond magnet 1 may be provided. The number of pins 12 that can be used may be other than eight.

Further, in the above-described embodiments, the configuration in which the bond magnet main body 11 has an arc shape as the segment shape has been described, but the bond magnet main body may have a semicylindrical shape. Further, as described above, the bond magnet body 11 may have a ring shape. The present invention is applicable to all bonded magnets having a light, thin, short, and small shape (segment shape or ring shape).

It should be understood that the disclosed embodiments are illustrative in all points and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include meanings equivalent to the claims and all modifications within the scope.

1-Pin Through Bond Magnet 2, 3, 4 Magnet Structure 11 Bond Magnet Main Body 12 Pin 12a One End 12b The Other End 12c Recess 21 Die 22 Upper Punch 22a Upper Punch Hole 23 Lower Punch 23a Lower Punch Recess 24 Cavity 25 Magnetic powder for bonded magnets 41, 45, 47 Yoke material 42, 46, 48 holes

Claims (6)

Segment-shaped or ring-shaped bonded magnet body,
A plurality of pins integrally penetrating the bond magnet main body in a manner that both ends thereof protrude from the bond magnet main body. The pin penetrating bond magnet according to claim 1, wherein the volume of the pin is 10% or less of the whole. The pin penetrating bond magnet according to claim 1 or 2, wherein a recess is formed in the center of the pin. The pin-penetrating bond magnet according to any one of claims 1 to 3, wherein the bonded magnet body contains a magnetic powder of an RTB-based alloy and a thermosetting resin. A single or a plurality of pin-penetrating bond magnets according to any one of claims 1 to 4,
And a yoke body having a plurality of holes into which one ends of the pins of the single or plurality of pin-penetrating bond magnets are fitted, respectively. Manufactures a pin-penetrating bond magnet in which a plurality of pins are integrally penetrated by projecting both ends of a segment-shaped or ring-shaped bonded magnet body using a compression molding device having an upper punch, a lower punch and a die. A method of manufacturing a pin-through bond magnet, comprising:
The upper punch is provided with an upper punch hole through which a pin is inserted, and the lower punch is provided with a lower punch recess for accommodating one end of the pin,
A step of producing a kneaded product of magnetic powder and thermosetting resin,
Disposing a pin in the lower punch recess,
Lowering the lower punch to form a cavity between the die and the lower punch,
In the formed cavity, a step of filling the prepared kneaded product,
Raising the pin to insert a part of the pin into the upper punch hole;
Compressing the kneaded material filled in the cavity by lowering the upper punch and/or raising the lower punch.

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