JP3132345B2 - Ferrite magnet forming equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a small magnet used in a linear motor or the like, and more particularly, to a powder magnetic field molding mold capable of easily carrying out a small magnet as a product from a mold. It concerns the device.

[0002]

2. Description of the Related Art Conventionally, a linear motor has been used for a device for automatically opening and closing a curtain of a one-box car, a curtain for a house window, and the like. This linear motor is a system in which a small movable coil runs by itself in a rail composed of a flexible wiring and a magnet, and is widely used because of its simple structure and easy and convenient mounting. FIG. 8 is a cross-sectional view showing the configuration of the linear motor. A flexible wiring 41 for supplying power is fixed to an inner left surface of a rail cover 42 having a U-shaped cross section. Also,
Ferrite magnet 4 magnetized on the right inner surface of rail cover 42
4 are fixedly arranged. And flexible wiring 4
A movable coil 43 composed of two coils is slidably mounted between the coil 1 and the ferrite magnet 44.

According to the magnetization pitch of the ferrite magnet,
A current is supplied to the movable coil 43 via the current collecting brush 45 from the flexible wiring 41 patterned so as to generate a thrust in the same direction. Here, the movable coil 43
Can be switched by changing the polarity of the current. The ferrite magnet 44 used in such a linear motor has, for example, a thickness of 4.2 mm, a width of 12 mm ×
A rectangular parallelepiped magnet having a length of 25 mm is formed by being closely adhered in series and adhered, and magnetized at regular intervals after the adhesion. Here, in order to operate the movable coil 43 smoothly, it is necessary to attach the flexible wiring 41 and the ferrite magnet 44 with high accuracy.

Next, a conventional method for manufacturing the ferrite magnet 44 will be described. Conventional manufacturing methods include a wet method and a dry method. The dry method is a method in which a ferrite particle is directly hardened by applying a high pressure, and is widely used because its production is simple. In the dry method, a strong magnetic field is applied when solidifying the ferrite particles to enhance the orientation of the ferrite particles. Next, a conventional mold apparatus for powder magnetic field molding of a ferrite magnet by a dry method will be described. The die is made of a non-magnetic material, and the pair of upper and lower punches is made of a ferromagnetic material.
Since the coil is provided around the mold so that a strong magnetic field is generated in the direction of movement of the punch, the ferrite particles are aligned in the direction of movement of the punch, and a magnet with good orientation can be obtained. However, when the punch is moved in the vertical direction as it is, the ferrite magnet is attracted to one of the pair of upper and lower punches, which are ferromagnetic materials, and it is difficult to remove the ferrite magnet from the mold. is there. In order to solve the problem, a ferrite magnet is demagnetized by applying a magnetic field in a direction opposite to that of the ferrite magnet after molding.

[0005]

However, the conventional powder magnetic field molding apparatus has the following problems.
In other words, when molding, even if the strength of the magnetic field is not uniform, it only adjusts the direction of the ferrite particles.
There is no problem, but when demagnetizing, there is a problem that demagnetization cannot be performed completely due to variations in the strength of the magnetic field. This is because a large number of punches are provided on one die in order to take a plurality of products, but the strength of the magnetic field varies depending on the location. For this reason, when the punch is moved in the vertical direction, the ferrite magnet may be attracted to the upper punch and may be attracted to the lower punch.Therefore, there is a problem in automatically removing the ferrite magnet by the robot. there were.

Conventionally, in order to solve this problem, the number of ferrite magnets in mold molding is reduced so as to reduce variations in magnetic flux density, and the ferrite magnets are gathered at the center of the mold and molded. In addition, a method has been adopted in which the ferrite magnet is formed into a large lump so that the ferrite magnet remains on the lower punch side depending on the weight and then divided. However, these solutions have very poor production efficiency.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a powder magnetic field molding apparatus capable of improving the production efficiency of a rectangular parallelepiped magnet.

[0008]

In order to solve the above-mentioned problems, a ferrite magnet forming apparatus according to the present invention comprises a non-magnetic material.
Several mold holes into which ferrite particles are injected
Die and, et al provided corresponding to the type hole made of a ferromagnetic material
Multiple upper and lower punches and how to move the punches
And a coil for generating a magnetic field in the
The injected ferrite particles are brought into the two
Multiple ferrite magnets simultaneously by compressing
An apparatus for forming a plurality of upper punches and lower punches.
A non-magnetic material film made of a plating layer is formed only on the upper punch among the punches . In addition, the present invention
The ferrite magnet molding apparatus is characterized in that, in the above-mentioned apparatus, a projection or a depression is formed on a surface of the punch different from the punch on which the nonmagnetic coating is formed.

Next, a method for producing a rectangular parallelepiped magnet for a linear motor using the powder magnetic field molding die apparatus of the present invention will be described. First, ferrite particles are injected into a mold of a mold apparatus for forming a powder magnetic field. Next, the punch is moved down and the ferrite particles are compression-molded into a solid state. During molding, a strong magnetic field is applied to the mold by the coil in the vertical direction. At this time, since the die is made of a non-magnetic material, and the upper and lower punches are made of a ferromagnetic material, the magnetic flux density between the upper and lower punches is higher than the magnetic flux density around the upper and lower punches. A magnetic field is generated.
Thereby, the ferrite particles are aligned in the moving direction of the punch, and a magnet having good orientation can be obtained.

Next, after molding, a current is applied to the coil in the opposite direction to generate a magnetic field in the mold in a direction opposite to that at the time of molding. Thereby, the ferrite magnet is demagnetized.
At this time, since the magnetic flux density of the magnetic field is not uniform and varies, the demagnetized state of the ferrite magnet also varies depending on the locations of the plurality of punches. However, since the non-magnetic film is formed on the surface of the upper punch, even if magnetic force remains on the ferrite magnet, the ferrite magnet has a strong attraction to the lower punch, which is a ferromagnetic material. Exists in a state of being adsorbed by the punch. Further, since the lower punch is formed with a convex portion or a concave portion, the contact area with the product increases, and the ferrite magnet is more strongly attracted to the lower punch by the attractive force at the convex portion or the concave portion, It always exists in a state of being adsorbed by the lower punch. Since the ferrite magnet is always attracted to the lower punch, the robot can easily take out the ferrite magnet.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a powder magnetic field molding apparatus according to an embodiment of the present invention; FIG. 3 is a conceptual diagram showing the overall configuration of the powder magnetic field molding die apparatus 9 and its peripheral devices. FIG. 1 is an enlarged view of a mold part which is a main part of the present invention. The lower punch table 28 made of a ferromagnetic material is used for the main body frame 1 of the mold apparatus.
4 fixed. The die plate 11, which is a die made of a non-magnetic metal, is held slidably in the vertical direction with respect to the lower punch table 28 and the lower punches 32 provided on the lower punch table 28. . In the center of the die plate 11, a plurality of rectangular holes 11 b, each of which is slightly larger than the product for forming the rectangular parallelepiped magnet G, are formed in view of the shrinkage allowance during sintering, corresponding to the lower punch 32. Have been.

As shown in FIG. 1, a rectangular hole 11b formed in the die plate 11 is fitted to the lower punch 32. On the upper surface of the lower punch 32, a lower concave mold 33 is formed. The lower punch 32 is made of a ferromagnetic metal. In the present embodiment, die steel is used.
Further, as shown in FIG. 4, a number mark convex portion 34 is formed on the surface of the lower concave mold 33 to identify which of the plurality of rectangular holes 11b has been formed. In FIG.
“3” is formed as a convex portion.

The die plate 11 is slid up and down by a moving cylinder 16. In the upper part of the die plate 11,
A moving upper punch 29 that can move in the vertical direction is provided. The moving upper punch 29 is made of a ferromagnetic metal. In the present embodiment, die steel is used. On the lower surface of the moving upper punch 29, an upper concave die 30 is formed.
On the surface of the upper concave mold 30, a hard chrome plating layer 31, which is a non-magnetic material, is formed. In the present embodiment, the thickness of the hard chrome plating layer 31 is 0.5 mm.
An upper cylinder 13 for vertically moving the movable upper punch 29 is provided above the movable upper punch 29.

A coil is provided around the die plate 11 and the moving upper punch 29 for applying a magnetic field to the ferrite particles to increase the orientation when forming the rectangular parallelepiped magnet G for a linear motor and performing demagnetization after the forming. 15 are provided.
On the right side of the die plate 11, the molded rectangular magnet G
A take-out device 23 is provided for taking out.
The take-out device 23 includes a belt conveyor 24, a vacuum pad 25 for sucking the rectangular parallelepiped magnet G, a take-out cylinder 27 for moving the vacuum pad 25 to the upper part of the die plate 11, and a vacuum pump 26 for applying a vacuum to the vacuum pad 25.
It is composed of

Next, a method for manufacturing a rectangular parallelepiped magnet G for a linear motor using the powder magnetic field molding die apparatus 9 having the above-described configuration will be described with reference to FIGS. FIG.
As shown in (a), the die plate 11 is located above the lower punch 32, and a recess formed by the lower punch 32 and the die plate 11 is formed. As shown in FIG. 5B, ferrite particle powder F is injected into the recess from a powder supply device (not shown). Next, as shown in FIG. 5C, the upper cylinder 13 is driven, and the moving upper punch 29 enters the die plate 11 and presses the ferrite particle powder F. Thereby, the rectangular parallelepiped magnet G is formed. At this time, a strong magnetic field M is applied to the ferrite particle powder F downward by the coil 15 as shown in FIG. 6D, and the ferrite particles are oriented in a certain direction.
The orientation of the rectangular parallelepiped magnet G can be increased.

Further, as shown in FIG. 6 (e), the upper punch 29 is moved downward to move the ferrite particle powder F.
Press. Next, as shown in FIG. 6F, the die plate 11 is moved downward together with the moving upper punch 29 to press the ferrite particle powder F. The reason why the die plate 11 is moved together with the upper punch 29 is that the density of the ferrite particle powder F can be made uniform by moving the die plate 11. Next, before the moving upper punch 29 and the die plate 11 are moved to take out the rectangular parallelepiped magnet G, as shown in FIG. G is demagnetized by applying a magnetic field N in the opposite direction.

Next, as shown in FIG. 7 (h), the die plate 11 is moved downward to the lower surface of the rectangular parallelepiped magnet G. Then, as shown in FIG.
9 is moved upward. At this time, a plurality of rectangular holes 1
1b, the magnetic flux density is high at the center of the mold and low at the peripheral portion, so that the demagnetization state of the rectangular parallelepiped magnet G differs depending on the location. However, in this embodiment, the hard chrome plating layer 3 which is a non-magnetic material is formed on the surface of the upper concave mold 30.
1, the upper punch 29 and the lower punch 32 were moved even if the rectangular parallelepiped magnet G had a magnetic force, because it was strongly attracted to the lower punch 32 without the hard chrome plating layer 31. Sometimes, the rectangular parallelepiped magnet G is always in close contact with the lower concave mold 33.

FIG. 2 shows the effect of the hard chrome plating layer 31 by data. The horizontal axis is the thickness (mm) of the nonmagnetic coating such as the hard chrome plating layer 31 and the vertical axis is the rectangular parallelepiped magnet G.
3 shows the attraction force between the lower punch 32 and the lower punch 32. Assuming that the adsorption force when the film thickness is zero is 100, the film thickness is 14 at 0.1 mm, 8 at 0.3 mm, and 6 at 0.5 mm. In the present embodiment, since the thickness of the hard chrome plating layer 31 is 0.5 mm, the lower punch 32
When the attraction force between the rectangular punch G and the rectangular parallelepiped magnet G is set to 100, the attraction force between the moving upper punch 29 and the rectangular parallelepiped magnet G is 6.
2 strongly adsorbed. Further, in the present embodiment,
Since the number stamping protrusions 34 are formed in the lower concave mold 33 of the lower punch 32, the contact area is increased by the unevenness of the number stamping protrusions 34, so that the rectangular parallelepiped magnet G is more strongly attracted to the lower punch 32. Therefore, the moving upper punch 29 and the lower punch 32
Is moved, the rectangular parallelepiped magnet G is always
Will be in close contact with the substrate.

Next, the moving upper punch 29 is moved upward by the upper cylinder 13. Since the formed rectangular magnet G is always present at a predetermined position of the lower punch 32, it is easily conveyed onto the conveyor 24 by the vacuum pad 25. The rectangular parallelepiped magnet G is then sintered in a sintering furnace,
Used as a rectangular magnet G for a linear motor. That is, since the predetermined outer dimensions are accurately formed in the sintered state, the ferrite magnets 44 for a linear motor are directly and closely adhered in series and magnetized at regular intervals after the adhesion. .

As described above in detail, the mold apparatus 9 for forming a powder magnetic field according to the present embodiment includes the die plate 11 made of a non-magnetic material and the moving upper punch 29 and the lower punch 32 made of a ferromagnetic material. And a coil 15 for forming a magnetic field in the mold.
Since the hard chrome plating layer 31, which is a non-magnetic coating, is formed on the surface of the upper concave mold 30, even if the demagnetization is not uniform and the magnetic force remains in the rectangular parallelepiped magnet G, the moving upper punch 29 and the lower punch 32 Is moved, the attraction force between the rectangular parallelepiped magnet G and the lower punch 32 is ten and several times stronger than the attraction force between the rectangular parallelepiped magnet G and the moving upper punch 29, so that the rectangular magnet G is always attracted to the lower punch 32. It can exist in a state where it is located.

Further, the mold apparatus 9 for molding a powder magnetic field according to the present embodiment comprises a lower punch 32 which is a punch opposed to the moving upper punch 29 on which the hard chromium plating layer 31 which is a nonmagnetic film is formed. Since the convex portions are formed on the surface, the contact area between the rectangular parallelepiped magnet G and the lower punch 32 can be increased, and the attraction force between the rectangular parallelepiped magnet G and the lower punch 32 can be further increased.

The embodiments of the present invention are not limited to the above-described embodiments, and various applications are possible. That is, in the present embodiment, the molding apparatus of the type in which the die plate 11 floats has been described, but the same applies to the case where the die plate 11 is a fixed type. In the present embodiment, the hard chromium plating layer 31 is used as the nonmagnetic film, but a ceramic layer may be used. Further, in the present embodiment, the thickness of the hard chrome plating layer 31 is 0.5 mm, but the thickness of the non-magnetic film may be 0.1 mm or more as shown in FIG.

[0023]

Apparent as from the above explanation, according to the present invention, ferrite magnets forming apparatus of the present invention, Ri formed of a non-magnetic material,
A die in which a plurality of mold holes into which ferrite particles are injected is formed, and a ferromagnetic material is provided corresponding to the mold holes.
A plurality of upper punches and lower punches, and
A coil for generating a magnetic field , and injected into each of the mold holes.
Punched ferrite particles in the magnetic field
To form multiple ferrite magnets simultaneously.
An apparatus for shaping , said plurality of upper punches and lower punches
The upper punch and the lower punch were moved even if the demagnetization was not uniform and the magnetic force remained in the rectangular parallelepiped magnet G because the nonmagnetic coating composed of the plating layer was formed only on the upper punch . Sometimes, the attraction force between the rectangular parallelepiped magnet G and the lower punch is
Since the attraction force of the rectangular magnet G and the moving upper punch is more than ten times higher, the rectangular magnet G can always be present in a state of being attracted to the lower punch.

[Brief description of the drawings]

FIG. 1 is an enlarged view of a mold part of a mold apparatus 9 for molding a powder magnetic field of the present invention.

FIG. 2 is a data diagram showing the effect of the present invention.

FIG. 3 is a conceptual diagram showing a configuration of a powder magnetic field molding die device 9 and peripheral devices.

FIG. 4 is an enlarged view showing a shape of a number stamping portion 34;

FIG. 5 is a drawing showing a first manufacturing process by a powder magnetic field molding die apparatus.

FIG. 6 is a view showing a second manufacturing process by a powder magnetic field molding die apparatus.

FIG. 7 is a view showing a third manufacturing step by a powder magnetic field molding die apparatus.

FIG. 8 is a sectional view showing a rectangular parallelepiped magnet G used in a linear motor.

[Explanation of symbols]

 Reference Signs List 9 Mold device for magnetic field molding 11 Die plate 11b Rectangular hole 28 Lower punch 29 Moving upper punch 30 Upper concave 31 Hard chrome plating layer 32 Lower punch 33 Lower concave 34 Number stamp

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01F 41/02 B22F 3/02

Claims (2)

(57) [Claims] [Claim 1] Ri consists of a non-magnetic material, ferrite particles Note
Die with multiple mold holes to be inserted and ferromagnetic material
A plurality of upper punches provided corresponding to the mold holes;
A ferrite particle having a lower punch and a coil for generating a magnetic field in the direction of movement of the punch, wherein the ferrite particles are injected into each of the mold holes.
By compressing the child with the two punches in the magnetic field.
Ferrite magnet to form multiple ferrite magnets simultaneously
In the stone forming apparatus, only the upper punch of the plurality of upper punches and lower punches is used.
A ferrite magnet molding device , wherein a non-magnetic film composed of a plating layer is formed . 2. The ferrite according to claim 1, wherein a protrusion or a recess is formed on a surface of the punch other than the punch on which the nonmagnetic film is formed. Magnet molding equipment.