JPH09165603A - Power packing method and powder packing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder packing method and a powder packing device which solve the occurrence of the bridging of powder and the difficulty in stable packing which arise heretofore when the powder is packed into cavities with the conventional powder molding device of annular parts. SOLUTION: At the time of packing the magnetic material powder 20 of a raw material into the cavity 11 by moving a shoe box 19 to over a die 1, a lower core 43 of a structure to be magnetized in the prescribed part is risen into the magnetic material powder 20 in the shoe box 19 until the magnetic material powder 20 adheres to the prescribed position on the outer periphery of the lower core 43 and, thereafter, the lower core is lowered down to a press execution position.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a powder filling method used in a molding press for molding a magnetic body (permanent magnet, soft magnetic material, iron-based mechanical parts, etc.) ring-shaped (thin hollow) powder compact. And a powder filling device.

[0002]

2. Description of the Related Art Conventionally, filling of raw material powder in a powder press is performed as follows. That is, in FIG. 6, by sliding the shoe box 19 onto the cavity 11 created by the die 1, the lower core 4 and the lower punch 2 as shown by the arrow a, the powder 21 is naturally dropped into the cavity 11. Then, the shoe box 19 is returned to its original position to form the molding space, that is, the cavity 11
Excess powder that cannot fit in is removed by scraping. In this case, the shoe box 19 is often reciprocated a plurality of times.

[0003]

However, when the cavity 11 is narrow and is about several millimeters, the powder may cause bridging depending on the properties of the powder even if the cavity 11 is reciprocated a plurality of times, and it is difficult to fill the powder. It was

In particular, a ferromagnetic powder such as a powder to which a binder is added or a powder for a permanent magnet is agglomerated and has poor fluidity. Therefore, the upper opening of the cavity 11 is narrow and the powder causes bridging to prevent the powder from dropping spontaneously, making it difficult to stably fill the powder.

The present invention has been made in view of the above-mentioned circumstances, and the conventional drawbacks have been solved by providing a magnetized portion in the lower core and raising it to the magnetic powder in the shoe box. A powder filling method and a powder filling device are provided.

[0006]

In order to solve the above-mentioned problems, the powder filling method of the present invention is such that the shoe box of the powder molding apparatus for ring-shaped parts is moved to the mold and magnetic powder of the raw material is put into the cavity. At the time of filling, a lower core having a structure in which a predetermined portion was magnetized was used, and this lower core was once lifted into the magnetic powder of the shoe box, and the magnetic powder was adhered to a predetermined position on the outer periphery of the lower core. After that, it is lowered to the press working position. Therefore, when the magnetized lower core rises into the magnetic powder of the shoe box, the magnetic powder adheres to the periphery of the lower core and is forcibly pulled when the lower core descends to the original position (pressing position). Enter the cavity.

In order to solve the above-mentioned problems, the powder filling device of the present invention is a powder molding device for a ring-shaped part, in which a lower part that is vertically movable is inserted into a cylindrical lower punch that is inserted into the mold from below. A part of the core is magnetized and magnetized.

Further, in the powder filling apparatus of the present invention, in the powder molding apparatus for ring-shaped parts, a part of the lower core which is vertically movable into a cylindrical lower punch inserted into the die from below is wound. It is a structure magnetized by a magnetized solenoid coil.

Further, in the powder filling apparatus of the present invention, in the powder molding apparatus for the ring-shaped part, the core which is vertically movable into the cylindrical lower punch which is inserted into the mold from the lower side has the work portion at the tip. It is a ferromagnetic material, and the portion following it is cylindrical and is formed of a hollow magnetizing case, and at least one permanent magnet is fitted and fixed to the tip of the magnetizing case.

Further, in the powder filling apparatus of the present invention, in the powder molding apparatus for the ring-shaped component, the lower core which is vertically movable into the cylindrical lower punch which is inserted into the die from below is the work portion at the tip. , And a cylindrical magnetizing case that is hollow inside and is made of a non-magnetic material, and at least one permanent magnet is fitted and fixed to the tip of the magnetizing case.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 and 2 are views for explaining the structure of the lower core of the present invention, FIGS. 3 and 4 are views for explaining the molding sequence of the ring magnet according to the present invention, and (e) to (j) are powder filling of the present invention. Although it is not related to the explanation of the method, magnetization → molding →
The powder filling apparatus of the present invention is applied to the apparatus of the present invention filed by the present applicant before the process of taking out the product is possible, and is illustrated for reference. FIG. 5 is a cross-sectional view showing a ring magnet molding apparatus using a conventional powder filling apparatus.

The method of the present invention will be described with reference to FIGS. 3 (a) to 3 (d). As shown in FIG. 3 (a), the magnetic powder 20 is placed on the cavity 11 as in the conventional filling step. The shoe box 19 is slid in the direction of arrow b.
Next, as shown in (b), the magnetized lower core 43 is raised into the magnetic powder 20 of the shoe box 19, and the powder is magnetically attracted to the magnetized portion of the lower core 43. Next, as shown in (c), when the lower core 43 is returned to the original position (pressing position), the adsorbed powder enters the cavity 11 and is filled in the cavities 11 up to the lower punch 2. Next, as shown in (d), the shoe box 19 is returned as shown by the arrow c as in the conventional case, and excess powder accumulated in the upper portion of the cavity 11 is scraped off. The difference from the conventional process is that the operation of FIG. 3B is added to the process.

The subsequent pressing step will be described with reference to FIGS. 3E to 4J. In FIG.
Slide to energize and orient the powder. In (f), the electromagnet 15 is returned to its original position. At (g), the upper punch 8 descends, and the magnetic powder is compression-molded. At (h), the upper punch 8 is returned to its original position. Slide the electromagnet 15 in (i), (e)
A static magnetic field or a pulsed magnetic field in the opposite direction is generated to demagnetize the molded body 25. After the electromagnet 15 slides away in (j), the lower punch 2 rises and the compact 25 is taken out.

Next, the structure of the lower core, which is the powder filling apparatus of the present invention, will be described. FIG. 1A shows the structure of claim 2, which is made of a hard magnetic material having an integral structure (for example, alloy tool steel of SKD11, ferromagnetic cemented carbide, etc.) and magnetized 41a in a ring shape as shown in the figure. In addition, the magnetic pattern is arbitrary such as vertical stripes and spirals. Further, the magnetizing position of the lower core 41 is appropriately selected depending on the molding method, such as the whole, only the upper portion, only the intermediate portion, and only the lower portion.

FIG. 1B shows the structure of claim 3,
The lower core 42 is an electromagnet that is energized from the power supply 23 to the solenoid coil 22.

FIG. 2A shows the structure of claim 4, wherein the work portion 43a at the tip is a ferromagnetic body, and the magnetizing case 43b at the subsequent portion is cylindrical and has a hollow inside and is made of a non-magnetic body. (For example, austenitic stainless steel, non-magnetic super steel, etc.). And, this magnetized case 43b
Two permanent magnets 24, 24 are fitted and fixed to the tip of the inside, and are sealed with a non-magnetic plug 43c. The number of the permanent magnets 24 may be one or three or more. This lower core 4
No. 3 is suitable for radial orientation molding.

FIG. 2B shows the structure of claim 5,
The work part 44a at the tip and the cylindrical magnetizing case 44b following the work piece 44a which is hollow inside are made of a non-magnetic material, and the two permanent magnets 24, 24 are fitted and fixed to the tip end in the magnetizing case 44b. It is sealed with a non-magnetic plug 43c.
The number of the permanent magnets 24 may be one or three or more. The lower core 44 is suitable for molding iron-based general mechanical parts. The shape of the lower core described above is arbitrary such as a ring shape and a rectangular shape depending on the shape of the molded body. In this case, it goes without saying that the shapes of the upper core and the upper and lower punches are adapted to them.

FIG. 5 shows a powder molding apparatus for a ring magnet which has been generally used up to now, and includes a lower ram 3 in which a lower punch 2 is inserted in a mold 1 and a lower ram 3 which is vertically movable. , And a lower punch 4 and a lower core 4 which forms a ring-shaped cavity 11 in the mold 1 together with the lower punch 2.

The mold 1 is installed in a yoke 5 forming a part of a magnetic path, and an upper core 7 is inserted in an upper ram 6 installed on the mold 1 so as to be able to move up and down. Reference numeral 8 denotes an upper punch integrated with the upper ram 6. A lower magnetizing coil 9 is arranged around the lower ram 3, and an upper magnetizing coil 10 is arranged around the upper ram 6. Also in the above-described ring magnet powder molding apparatus as shown in FIG. 5,
The present invention is applicable.

Furthermore, the present invention is not limited to the powder molding device for the ring magnet, but can be widely applied to a molding device for pressing the powder of the magnetic material.

[0021]

According to the present invention described in detail above, the following effects can be obtained. (1) The powder is magnetically attracted to the lower core that rises into the magnetic powder of the shoe box, and when the lower core descends to its original position, the powder is forcibly pulled and enters the cavity. As described above, the powder does not cause bridging in the cavity to make filling difficult. Therefore, even if the powder has agglomerated particles and poor fluidity, such as a powder to which a binder is added or a ferromagnetic powder for a permanent magnet, a required fixed amount of powder can be easily filled in the cavity.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a configuration of a lower core according to an embodiment of the present invention, in which (a) is the configuration of claim 2 and (b) is the configuration of claim 3.

FIG. 2 is a diagram illustrating a configuration of a lower core according to an embodiment of the present invention, in which (a) is the configuration of claim 4 and (b) is the configuration of claim 5;

FIG. 3 shows an embodiment of the present invention, in which the former stages of the ring magnet forming sequence are (a), (b), (c), (d),
It is explanatory drawing shown in (e).

FIG. 4 shows an embodiment of the present invention, in which the subsequent steps of the ring magnet forming order are (f), (g), (h), (i),
It is explanatory drawing shown in (j).

FIG. 5 is a cross-sectional view showing a ring magnet molding apparatus in which a conventional powder filling apparatus is used.

FIG. 6 is an explanatory diagram of a filling method using a conventional powder filling device.

[Explanation of symbols]

 1 Mold 2 Lower Punch 11 Cavity 19 Shoe Box 20 Magnetic Powder 22 Solenoid Coil 24 Permanent Magnet 41, 42, 43, 44 Lower Core 41a Magnetized 43a, 44a Work Part 43b, 44b Magnetized Case 43c Plug

Claims (5)

[Claims] 1. A lower core having a structure in which a predetermined portion is magnetized when a shoe box of a powder molding device for a ring-shaped component is moved onto a mold to fill a raw material magnetic powder into a cavity, A powder filling method characterized in that the lower core is once moved up into the magnetic powder of the shoe box, the magnetic powder is attached to a predetermined position on the outer periphery of the lower core, and then the magnetic core is lowered to a press working position. 2. A powder molding apparatus for a ring-shaped part,
1. A powder filling device, wherein a part of a lower core that is vertically inserted into a cylindrical lower punch that is inserted into a die from below is magnetized and magnetized. 3. A powder molding apparatus for ring-shaped parts,
A powder filling device, wherein a part of a lower core that is vertically inserted into a cylindrical lower punch that is inserted into a mold from below is magnetized by a wound solenoid coil. 4. A powder molding apparatus for ring-shaped parts,
The core that is vertically inserted into the cylindrical lower punch that is inserted into the die from the bottom is made up of a ferromagnetic material at the work piece at the tip, a cylindrical part at the end, and a hollow magnetized case inside. The powder filling device is characterized in that at least one permanent magnet is fitted and fixed to a tip portion of the magnetized case. 5. A powder molding apparatus for ring-shaped parts,
The lower core, which is vertically inserted into a cylindrical lower punch that is inserted into the die from below, has a work piece at the tip, and a cylindrical magnetizing case that follows and has a hollow interior made of a non-magnetic material. A powder filling device, wherein at least one permanent magnet is fitted and fixed to a tip portion of the magnetized case.