JP7290491B2 - BOND MAGNET MANUFACTURING DEVICE AND BOND MAGNET MANUFACTURING METHOD - Google Patents

Description

The present invention relates to a bonded magnet manufacturing apparatus and a bonded magnet manufacturing method.

When manufacturing a bond magnet, after filling the cavity with magnetic powder, compression molding is performed between an upper punch and a lower punch to produce a compact. In such a manufacturing method, when filling the magnetic powder into the cavity, a sliding jig (filling head) holding the magnetic powder is slid along the sliding surface of the base on which the cavity opens upward, and a certain amount of the magnetic powder is filled. The cavity is filled with magnetic powder (see Patent Document 1).

JP-A-2005-5686

For the purpose of increasing the density of a bonded magnet, the inventors of the present application have studied warm molding in which magnet powder coated with a thermosetting resin is filled into a cavity and then compression molded while being heated. In addition, we are studying to increase the density of the bonded magnet by performing warm molding at a high temperature that shortens the gelling time of the thermosetting resin. However, when the filling head slides along the sliding surface of the base and the magnetic powder is filled in the cavity and the temperature inside the cavity is set high, the heat of the base is transmitted to the filling head and held by the filling head. The temperature of the magnetic powder rises. As a result, the thermosetting resin coated on the magnetic particles gels, causing the magnetic particles to adhere to each other, making it impossible to properly fill the cavities with the magnetic particles from the filling head.

In view of the above problems, an object of the present invention is to provide a bonded magnet manufacturing apparatus and a bonded magnet manufacturing method suitable for warm molding of bonded magnets.

In order to solve the above problems, one aspect of the present invention provides a bonded magnet manufacturing apparatus that includes a base having a sliding surface with a cavity opening upward, a magnetic powder outlet opening downward, and a thermosetting magnet. A standby position in which magnetic particles coated with resin are held inside and moved relative to the base along the sliding surface so that the magnetic particle discharge port is closed by the sliding surface and the magnetic powder discharge port are separated from each other by the sliding surface. A filling head that repeatedly moves to a filling position that overlaps a cavity, a punch that compresses and molds the magnetic powder filled in the cavity, a heating device that heats the inside of the cavity, and the magnetic powder held by the filling head. and a cooling device for cooling.

Another aspect of the present invention is a method for manufacturing a bonded magnet, in which a base having a sliding surface with an upwardly opening cavity and a downwardly opening magnetic powder discharge port are coated with a thermosetting resin. A standby position where the magnetic particle discharge port is closed by the sliding surface by relatively moving with respect to the base along the sliding surface while being held inside, and a filling position where the magnetic particle discharge port overlaps with the cavity. a punch for compression molding the magnetic powder filled in the cavity; a heating device for heating the inside of the cavity; and a cooling device for cooling the magnetic powder held by the filling head. It is provided in a bonded magnet manufacturing apparatus, and after the magnetic powder is filled into the cavity from the filling head moved to the filling position, the magnetic powder is compression-molded by the punch while the magnetic powder in the cavity is heated. do.

In the present invention, after the filling head slides on the slide surface of the base to move from the standby position to the filling position and fills the cavity with the magnetic powder, the filling head slides on the slide surface of the base to move from the filling position to the standby position. While moving, the magnetic powder in the cavity is compression-molded by the punch while being heated by the heating device. At that time, heat is transferred to the filling head from the sliding surface of the base, but the magnetic powder held on the filling head is cooled by the cooling device. For this reason, it is possible to suppress gelation of the thermosetting resin coated on the magnetic particles held by the filling head, so that it is possible to suppress the magnetic particles held by the filling head from adhering to each other. . Therefore, even if the operation of filling the cavity with the magnetic powder from the filling head is repeated, the magnetic powder can be appropriately filled into the cavity from the filling head. Therefore, the density of the bonded magnet can be increased by increasing the temperature for heating the magnetic powder in the cavity, making it suitable for warm molding of the bonded magnet.

In the present invention, it is possible to employ an aspect in which the filling head linearly reciprocates between the standby position and the filling position.

In the present invention, the heating device may heat the inside of the cavity from the side of the base opposite to the standby position with respect to the cavity. According to this aspect, it is possible to further suppress the temperature rise of the filling head.

In the present invention, the sliding surface is a continuous plane, and the cooling device cools the magnetic powder held in the filling head via the sliding surface from a position below the sliding surface. can do. According to this aspect, it is possible to suppress wear of the filling head due to sliding of the filling head on the sliding surface.

In the present invention, the cooling device may employ a refrigerant system in which a refrigerant flows through a channel.

In the present invention, it is possible to employ an aspect in which the base is provided with a heat insulating member between the cooling device and the cavity. According to this aspect, even when the cooling device is provided on the base side, the inside of the cavity can be properly heated.

In the present invention, after the filling head slides on the slide surface of the base to move from the standby position to the filling position and fills the cavity with the magnetic powder, the filling head slides on the slide surface of the base to move from the filling position to the standby position. While moving, the magnetic powder in the cavity is compression-molded by the punch while being heated by the heating device. At that time, heat is transferred to the filling head from the sliding surface of the base, but the magnetic powder held on the filling head is cooled by the cooling device. For this reason, it is possible to suppress gelation of the thermosetting resin coated on the magnetic particles held by the filling head, so that it is possible to suppress the magnetic particles held by the filling head from adhering to each other. . Therefore, even if the operation of filling the cavity with the magnetic powder from the filling head is repeated, the magnetic powder can be appropriately filled into the cavity from the filling head. Therefore, the density of the bonded magnet can be increased by increasing the temperature for heating the magnetic powder in the cavity, making it suitable for warm molding of the bonded magnet.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory diagram schematically showing a planar configuration of a bonded magnet manufacturing apparatus to which the present invention is applied; FIG. 2 is an explanatory view schematically showing a cross-sectional configuration of the bonded magnet manufacturing apparatus shown in FIG. 1; Explanatory drawing which shows the manufacturing method of the bond magnet to which this invention is applied.

A bond magnet manufacturing apparatus 1 to which the present invention is applied and a manufacturing method thereof will be described below with reference to the drawings.

(Overall Configuration of Bonded Magnet Manufacturing Apparatus 1)
FIG. 1 is an explanatory diagram schematically showing a planar configuration of a bonded magnet manufacturing apparatus 1 to which the present invention is applied. FIG. 2 is an explanatory diagram schematically showing a cross-sectional configuration of the bonded magnet manufacturing apparatus 1 shown in FIG. 1 and 2 show three spatial axes orthogonal to each other, the X-axis, the Y-axis, and the Z-axis. The X-axis direction (direction along the X-axis) is the sliding direction of the filling head 20, the Z-axis direction (direction along the Z-axis) is the vertical direction, and the X-axis direction (direction along the X-axis) is the width direction. is.

The bonded magnet manufacturing apparatus 1 shown in FIGS. 1 and 2 includes a base 10 having a sliding surface 12 with a cavity 11 opening upward, and a filling head 20 holding magnetic powder M coated with a thermosetting resin. and two punches (a lower punch 17 and an upper punch 16) for compression-molding the magnetic powder M filled in the cavity 11. As shown in FIG. The base 10 includes a metal plate 13 forming a sliding surface 12 and guide rails 15 fixed to both sides of the plate 13 in the Y-axis direction with bolts 14 . The bond magnet manufacturing apparatus 1 has a heating device 30 that heats the inside of the cavity 11 and a thermocouple 35 that detects the temperature on the side of the cavity 11, and warm forming is performed in the bond magnet manufacturing apparatus 1. . Magnetic powder M is, for example, magnetic powder M for manufacturing rare earth magnets such as neodymium magnets. The thermosetting resin is an epoxy resin or the like, which, for example, begins to melt when heated to a temperature of 50°C to 60°C, and hardens when heated to a temperature of 150°C to 230°C. For example, the bonded magnet manufacturing apparatus 1 of the present embodiment compresses the magnetic powder M into the shape of the bonded magnet by warm molding at a temperature of 55° C. to 60° C., and the obtained compact W is heated to 150° C. or higher in another apparatus. The thermosetting resin is cured by heating at a temperature of , and then magnetized.

In this embodiment, since a cylindrical bonded magnet is manufactured, the cavity 11 is a through hole with a circular cross section. The lower punch 17 has a cylindrical portion 171 having an outer diameter substantially equal to the inner diameter of the cavity 11 and a shaft portion 172 projecting upward from the upper end of the cylindrical portion 171 . The upper punch 16 has a cylindrical portion 161 having an outer shape substantially the same as the inner diameter of the cavity 11, and is coaxial with the lower punch 17 in the Z-axis direction.

The filling head 20 is a substantially rectangular parallelepiped metal box 24 with a magnetic powder outlet 25 opening downward. ) is connected. The filling head 20 moves relative to the base 10 along the sliding surface 12 while holding the magnetic particles M inside, and moves between the standby position P1 where the magnetic particle discharge port 25 is closed by the sliding surface 12 and the magnetic powder discharge port 25. repeatedly moves to the cavity 11 and the overlapping filling position P2. At that time, the lower end of the front wall 22 or the rear wall 23 slides on the sliding surface 12 to scrape off the magnetic particles M. As shown in FIG.

In this embodiment, the base 10 is fixed in the X-axis direction, and the filling head 20 linearly reciprocates in the X-axis direction between the standby position P1 and the filling position P2. More specifically, the filling position P2 is set on one side X1 of the standby position P1 in the X-axis direction, and the standby position P1 is located on the other side X2 of the cavity 11 in the X-axis direction.

In this embodiment, the heating device 30 is two cartridge heaters 31 arranged at positions spaced apart in the Y-axis direction. Here, the heating device 30 heats the inside of the cavity 11 from the side of the base 10 opposite to the standby position P1 with respect to the cavity 11 . More specifically, the heating device 30 is arranged inside the base 10 on the opposite side (one side X1 in the X-axis direction) of the cavity 11 from the standby position P1. heats the inside of the cavity 11 from the .

(Configuration of cooling device 40, etc.)
The bonded magnet manufacturing apparatus 1 is provided with a cooling device 40 for cooling the magnetic powder M held inside the filling head 20 . In this embodiment, the cooling device 40 is provided on the standby position P1 side of the cavity 11 in the base 10 . More specifically, the cooling device 40 is provided in the base 10 so as to extend from between the cavity 11 and the standby position P1 to a position overlapping the standby position P1. A cooling portion is formed by the cooling device 40 from the interval to the position slightly passing the standby position P1 on the other side X2 in the X-axis direction.

The cooling device 40 is provided inside the base 10 and is not exposed to the running surface 12 . Therefore, the cooling device 40 cools the magnetic particles M held inside the filling head 20 via the sliding surface 12 from below the sliding surface 12 . Therefore, the sliding surface 12 is cooled by the cooling device 40 from between the cavity 11 and the standby position P1 to a position slightly passing the standby position P1. In addition, the sliding surface 12 is a continuous flat surface without steps or the like caused by the cooling device 40 .

The cooling device 40 is of a refrigerant type in which a refrigerant flows through a channel 41 . More specifically, a channel 41 is formed inside the base 10 , and the coolant flows through the channel 41 inside the base 10 . In this embodiment, the cooling device 40 is of a water cooling type, and cooling water as a coolant flows through the flow path 41 . Here, a chiller is connected to the flow path 41 , and cooling water whose water temperature is controlled to 25° C., for example, flows through the flow path 41 . In addition, the cooling water may not be cooled by the chiller. Further, the cooling device 40 may adopt an air cooling system or a cooling system using a Peltier element or the like instead of the water cooling system.

A heat insulating member 50 is provided in the base 10 between the cooling device 40 and the cavity 11 . In this embodiment, between the cooling device 40 and the cavity 11, there is provided a plate-shaped heat insulating member 50 made of a laminate obtained by impregnating a base material such as paper, cotton cloth, or glass cloth with phenolic resin or the like and then curing the same. It is The heat insulating member 50 is provided inside the base 10 and is not exposed on the sliding surface 12 . For this reason, the sliding surface 12 is a continuous flat surface without steps or the like caused by the heat insulating member 50 .

(Manufacturing method of bonded magnet)
Next, a method for manufacturing a bonded magnet will be described. FIG. 3 is an explanatory view showing a method of manufacturing a bonded magnet to which the present invention is applied, and is a process cross-sectional view showing a compression molding process of magnetic powder M. In FIG. First, in the preparation step ST1, the filling head 20 is at the standby position P1, so the discharge port 23 of the filling head 20 is blocked by the sliding surface 12. As shown in FIG. Also, the lower punch 17 is arranged inside the cavity 11 so as to block the opening 111 on the lower side of the cavity 11 . In this state, the interior of the cavity 11 is heated by the heating device 30, and cooling water is circulating in the flow path 41 in the cooling device 40. As shown in FIG.

Next, in the filling step ST2, when the filling head 20 moves from the standby position P1 to the filling position P2, the discharge port 23 of the filling head 20 overlaps with the cavity 11, so the magnetic powder M falls into the cavity 11 by its own weight. , the magnetic powder M is filled in the cavity 11 .

Next, in the scraping step ST3, the filling head 20 returns to the standby position P1. At this time, the opening 112 on the upper side of the cavity 11 is scraped by the filling head 20 , so that the cavity 11 is filled with a certain amount of magnetic powder M. Further, when the filling head 20 passes through the place where the heat insulating member 50 is arranged and passes through the area where the cooling device 40 is arranged, and stops at the standby position P1 where the cooling device 40 is arranged. During this time, the magnetic powder M held inside the filling head 20 is cooled through the sliding surface 12 by the cooling device 40 .

Next, in the compression step ST4, the upper punch 16 is moved downward Z1 in the Z-axis direction to enter the cavity 11. As shown in FIG. Then, by compressing the magnetic powder M in the Z-axis direction between the upper punch 16 and the lower punch 17, the molded body W of the bond magnet is manufactured. At that time, the thermosetting resin coated on the magnetic particles M melts, so that the magnetic particles M can be compressed without gaps. As a result, the bonded magnet manufacturing apparatus 1 can manufacture the compact W with a high density.

Next, in the discharge step ST5, the upper punch 16 is moved to the upper side Z2 in the Z-axis direction, and the lower punch 17 is moved to the upper side Z2 in the Z-axis direction to push out the compact W from the cavity 11 to the upper side Z2. After that, the molded body W is discharged to one side X1 in the X-axis direction, and the manufacturing process of the molded body W is completed. Henceforth, said process (preparation process ST1, filling process ST2, scraping process ST3, compression process ST4, and discharge process ST5) is repeated.

(Main effects of this form)
As described above, in the bonded magnet manufacturing apparatus 1 and the bonded magnet manufacturing method of the present embodiment, the filling head 20 slides on the sliding surface 12 of the base 10 to move from the standby position P1 to the filling position P2 and enter the cavity 11. After filling the magnetic powder M, the filling head 20 slides on the sliding surface 12 of the base 10 and moves from the filling position P2 to the standby position P1. Compression molding is performed between the punch 17 and the upper punch 16 . At that time, the filling head 20 receives heat from the sliding surface 12 of the base 10 , but the magnetic powder M held by the filling head 20 is cooled by the cooling device 40 . Therefore, it is possible to suppress gelation of the thermosetting resin coated on the magnetic particles M held by the filling head 20, thereby suppressing the magnetic particles M held by the filling head 20 from adhering to each other. can do. Therefore, even if the operation of filling the cavity 11 with the magnetic powder M from the filling head 20 is repeated, the magnetic powder M can be properly filled into the cavity 11 from the filling head 20 . Therefore, the temperature for heating the magnetic powder M in the cavity 11 can be increased to increase the density of the bond magnet, thereby increasing the magnetic force of the bond magnet.

For example, when the inside of the cavity 11 is heated to a temperature of 40° C., the rearrangement of the magnetic powder M during compression can be promoted, so the density of the bond magnet is higher than when the inside of the cavity 11 is at room temperature. can be enhanced. In addition, according to this embodiment, the inside of the cavity 11 can be heated to a higher temperature (for example, 55° C. to 60° C.), so that the rearrangement of the magnetic powder M when compressed can be further promoted. The density of the bonded magnet can be further increased. For example, when the inside of the cavity 11 is at room temperature, the density of the bonded magnet is 5.8 g/cm ³ , but when the inside of the cavity 11 is heated to a temperature of 40° C., the density of the bonded magnet is 6.0 g/cm 3 . cm ³ , and when the inside of the cavity 11 is heated to a temperature of 55° C. to 60° C., the density of the bonded magnet can be increased to 6.2 g/cm ³ .

Further, since the heating device 30 heats the inside of the cavity 11 from the side of the base 10 opposite to the standby position P1 with respect to the cavity 11, the temperature rise of the filling head 20 can be further suppressed.

Further, since the cooling device 40 is provided below the sliding surface 12, the sliding surface 12 is a continuous plane. Therefore, the wear of the filling head 20 and the sliding surface 12 due to the filling head 20 sliding on the sliding surface 12 can be suppressed.

(Other forms)
In the above embodiment, the filling head 20 moves relative to the base 10. However, the present invention can be applied to a turntable in which the base 10 is provided with a plurality of cavities 11 in the circumferential direction. may In this case, standby positions P1 are set between the plurality of cavities 11 in the base 10 . Therefore, even if the filling head 20 is fixed, when the base 10 (turntable) rotates, the filling head 20 repeatedly moves between the standby position P1 and the filling position P2. be able to.

Although the cooling device 40 is provided in the base 10 in the above embodiment, the cooling device 40 may be provided in the filling head 20 itself.

DESCRIPTION OF SYMBOLS 1... Bond magnet manufacturing apparatus, 10... Base, 11... Cavity, 12... Slide surface, 16... Upper punch, 17... Lower punch, 20... Filling head, 25... Magnetic powder discharge port, 30... Heating device, 40... Cooling device, 41... Flow path, 50... Heat insulating member, M... Magnetic powder, P1... Standby position, P2... Filling position, W... Molded body

Claims (7)

a base having a sliding surface with a cavity opening upward;
A magnetic particle outlet is opened downward, and the magnetic particle outlet is relatively moved along the sliding surface with respect to the base while holding magnetic particles coated with a thermosetting resin inside the sliding surface. a filling head that repeatedly moves between a standby position closed with a and a filling position where the magnetic powder discharge port overlaps with the cavity;
a punch for compression molding the magnetic powder filled in the cavity;
a heating device for heating the inside of the cavity;
a cooling device for cooling the magnetic powder held by the filling head;
A bonded magnet manufacturing apparatus comprising: In the bonded magnet manufacturing apparatus according to claim 1,
The bonded magnet manufacturing apparatus, wherein the filling head linearly reciprocates between the standby position and the filling position. In the bonded magnet manufacturing apparatus according to claim 2,
The bonded magnet manufacturing apparatus, wherein the heating device heats the inside of the cavity from a side of the base opposite to the standby position with respect to the cavity. In the bonded magnet manufacturing apparatus according to any one of claims 1 to 3,
The running surface is a continuous plane,
The bonded magnet manufacturing apparatus, wherein the cooling device cools the magnetic powder held in the filling head via the sliding surface from a position below the sliding surface. In the bonded magnet manufacturing apparatus according to any one of claims 1 to 4,
The bonded magnet manufacturing apparatus, wherein the cooling device is of a cooling system in which a cooling medium flows in a channel. In the bonded magnet manufacturing apparatus according to any one of claims 1 to 5,
A bonded magnet manufacturing apparatus, wherein the base is provided with a heat insulating member between the cooling device and the cavity. a base having a sliding surface with a cavity opening upward;
A magnetic particle outlet is opened downward, and the magnetic particle outlet is relatively moved along the sliding surface with respect to the base while holding magnetic particles coated with a thermosetting resin inside the sliding surface. a filling head that repeatedly moves between a standby position closed with a and a filling position where the magnetic powder discharge port overlaps with the cavity;
a punch for compression molding the magnetic powder filled in the cavity;
a heating device for heating the inside of the cavity;
a cooling device for cooling the magnetic powder held by the filling head;
is provided in the bonded magnet manufacturing equipment,
A method for producing a bonded magnet, characterized in that after the magnetic powder is filled into the cavity from the filling head moved to the filling position, the magnetic powder is compression-molded by the punch while the magnetic powder in the cavity is heated.

Images