CN110027094B

CN110027094B - Ferrite magnetic ring radial wet pressing die

Info

Publication number: CN110027094B
Application number: CN201910387469.8A
Authority: CN
Inventors: 黄群欢
Original assignee: Individual
Current assignee: Huang Qunhuan
Priority date: 2019-05-10
Filing date: 2019-05-10
Publication date: 2023-11-14
Anticipated expiration: 2039-05-10
Also published as: CN110027094A

Abstract

The invention provides a ferrite magnetic ring radial wet pressing die which comprises a middle die, an upper male die and a lower male die, wherein a cavity which penetrates up and down is arranged on the middle die, the transverse width of the cavity is adapted to the height of a magnetic ring, the longitudinal width of the cavity is adapted to the maximum diameter of the magnetic ring, the outer walls of the upper male die and the lower male die are attached to the inner walls of the cavity, the front end faces of the upper male die and the lower male die are of inwards-sinking semi-arc shapes which are adapted to the outer walls of the magnetic ring, and drain holes are uniformly formed in the front end faces of the upper male die and the lower male die. Because the front end surfaces of the upper male die and the lower male die are respectively matched with the shape of the circular outer wall of the magnetic ring, the upper male die and the lower male die run in the cavity in opposite directions and squeeze slurry in the cavity, redundant water is uniformly discharged from the end surfaces of the upper male die and the lower male die, so that the water content of a formed magnetic ring green body along the length direction is consistent, the explosion phenomenon in the sintering process is avoided, and the yield of a magnetic ring finished product is improved.

Description

Ferrite magnetic ring radial wet pressing die

Technical Field

The invention relates to the technical field of dies, in particular to a ferrite magnetic ring radial wet pressing die.

Background

The magnetic ring is a common element in an electronic circuit and is pressed by ferrite materials, the specific pressing modes are dry type and wet type, in order to obtain the magnetic ring with better magnetic performance, the magnetic orientation is carried out in the pressing process, and the raw materials used in the wet pressing method are slurry added with about 33-37% of water, so that the molding and the orientation are more convenient, and the wet pressing method is widely used. As shown in fig. 1, the conventional pressing mold comprises an upper male die, a lower male die, a female die and a core bar which are axially arranged along a magnetic ring, wherein the female die, the lower male die and the core bar form a cavity, slurry is added into the cavity of the mold, and a high-frequency magnetic field is generated by a coil arranged at the periphery of the cavity to orient the slurry in the cavity and press the slurry while the mold is closed. Because about 17% of water is required to be discharged in the forming process, water discharge is usually realized on the upper end face and the lower end face of the die, so that for a magnetic ring with a higher height, water discharge is uneven, the water content in the middle part of a magnetic ring green compact is higher than that in the two ends, and expansion explosion easily occurs in the middle part of the magnetic ring due to excessive water in the sintering process.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a ferrite magnetic ring radial wet pressing die which is completely different from the existing die for axially pressing ferrite magnetic rings and adopts a radial pressing die, has a simple and reasonable structure, and ensures that water in each part of a green body of the magnetic ring can be uniformly discharged.

The present invention achieves the above object by:

the ferrite magnetic ring radial wet pressing die comprises a middle die, an upper male die and a lower male die, wherein a cavity which penetrates up and down is arranged on the middle die, the transverse width of the cavity is adaptive to the height of a magnetic ring, the longitudinal width of the cavity is adaptive to the maximum diameter of the magnetic ring, the outer walls of the upper male die and the lower male die are attached to the inner wall of the cavity, the front end faces of the upper male die and the lower male die are of inwards-sinking semi-arc shapes which are adaptive to the outer wall of the magnetic ring, and drain holes are uniformly formed in the front end faces of the upper male die and the lower male die.

Further, a transverse through hole is formed in the middle of the middle die, a mandrel which is matched with the inner hole of the magnetic ring is movably installed in the through hole, and the mandrel transversely penetrates through the middle of the cavity.

Further, at least two coaxial cavities are arranged on the middle die, and the mandrel penetrates through the adjacent coaxial cavities.

Further, the upper male die and the lower male die comprise a front end non-magnetic conductive material punch and a rear end magnetic conductor which are integrally formed, and the thickness of the punch is in transition along the semi-arc-shaped end surface, and the middle of the punch is thin, and the two ends of the punch are thick and circular arc.

The invention has the beneficial effects that: the invention provides a ferrite magnetic ring radial wet pressing die, which adopts radial pressing along a magnetic ring, wherein an upper male die and a lower male die are respectively arranged in an upper penetrating cavity and a lower penetrating cavity of a middle die, the front end surfaces of the upper male die and the lower male die are respectively matched with the shape of a circular outer wall of the magnetic ring, the upper male die and the lower male die run in the cavity in opposite directions and press slurry in the cavity, redundant water is uniformly discharged from the end surfaces of the upper male die and the lower male die, so that the water content of a formed magnetic ring green body along the length direction is consistent, the explosion phenomenon in the sintering process is avoided, and the yield of a magnetic ring finished product is improved.

Drawings

The invention is further illustrated by the following examples in conjunction with the accompanying drawings:

FIG. 1 is a schematic diagram of a magnetic ring mold of the background art;

FIG. 2 is a schematic cross-sectional view of an embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of another embodiment of the present invention;

fig. 4 is a schematic diagram of the middle mold in fig. 3.

In the figure, a middle die 1, a die cavity 11, a through hole 12, an upper male die 2 and a lower male die 3.

Detailed Description

Referring to fig. 2, the ferrite magnetic ring radial wet pressing die comprises a middle die 1, an upper male die 2 and a lower male die 3, wherein a cavity 11 penetrating up and down is arranged on the middle die 1, the transverse width of the cavity 11 is equal to the height of the magnetic ring, the longitudinal width of the cavity 11 is equal to the maximum diameter of the magnetic ring, the outer walls of the upper male die 2 and the lower male die 3 are attached to the inner wall of the cavity 11, the end surfaces of the upper male die 2 and the lower male die 3 are in an inward semi-arc shape which is matched with the outer wall of the magnetic ring, and drain holes are uniformly formed in the front end surfaces of the upper male die 2 and the lower male die 3.

The upper punch 2 and the lower punch 3 are embedded into the cavity 11, quantitative slurry is injected into the cavity 11, so that the upper punch 2 and the lower punch 3 run in opposite directions to perform extrusion forming, the radial dimension of the extrusion forming is consistent up and down, the extruded redundant water is uniformly discharged from the water discharge holes of the front end surfaces of the upper punch 2 and the lower punch 3, the consistency of the residual water content of the formed magnetic ring green compact along the length direction is ensured, explosion does not occur in the subsequent sintering process, the magnetic ring extruded by the die is solid, and the magnetic ring can be machined to form a magnetic ring shape according to requirements.

Referring to fig. 3, a transverse through hole 12 is formed in the middle of the middle mold 1, a mandrel corresponding to the inner hole of the magnetic ring is movably installed in the through hole 12, and the mandrel transversely passes through the middle of the cavity 11.

The outer diameter of the mandrel is equal to the inner diameter of a central hole of the magnetic ring, the mandrel is inserted into a transverse through 12 in the middle of a cavity 11 in advance, slurry is injected into the cavity 11, and in order to prevent the mandrel from bending deformation, the upper punch 2 and the lower punch 3 respectively squeeze and run at a constant speed in opposite directions, the upper stroke and the lower stroke are ensured to be consistent, and the mandrel is pulled out after forming.

At least two coaxial cavities 11 are arranged on the middle die 1, and the mandrel penetrates through the adjacent coaxial cavities 11.

Referring to fig. 4, to improve the production efficiency, one set of die may have multiple sets of cavities 11, and an upper punch 2 and a lower punch 3, and the same mandrel may also pass through adjacent coaxial cavities 11 at the same time.

The front ends of the upper punch 2 and the lower punch 3 are non-magnetic conductive material punches, the rear ends are magnetic conductors of an integrated structure, and the thicknesses of the punches are in transition along the semi-arc-shaped end surface with thin middle and thick circles at the two ends.

The magnetic orientation of the magnetic ring along the radial direction and the radial extrusion forming can be completed simultaneously, and because the extrusion is carried out along the radial direction and the extrusion end surface is arc-shaped, in order to ensure that the magnetic force of the magnetic ring along the radial direction is uniform, the upper punch 2 and the lower punch 3 are divided into a punch made of non-magnetic conductive materials at the front end and a magnetizer at the rear end, the punch part can be made of stainless steel materials, the thickness of the punch part is inconsistent along the semi-arc-shaped end, and the punch part is thin in the middle and thick at the two ends.

Therefore, the ferrite magnetic ring radial wet pressing die has simple structure and even extrusion stress, ensures that the magnetic ring keeps even drainage in the forming process, and greatly improves the yield of the magnetic ring.

Claims

1. Ferrite bead radial wet pressing mould, its characterized in that: the novel magnetic ring forming die comprises a middle die (1), an upper male die (2) and a lower male die (3), wherein a cavity (11) penetrating up and down is formed in the middle die (1), the transverse width of the cavity (11) is equal to the height of a magnetic ring, the longitudinal width of the cavity (11) is equal to the maximum diameter of the magnetic ring, the outer walls of the upper male die (2) and the lower male die (3) are attached to the inner walls of the cavity (11), the front end faces of the upper male die (2) and the lower male die (3) are of an inward-sinking semi-arc shape which is matched with the outer walls of the magnetic ring, and drain holes are uniformly formed in the front end faces of the upper male die (2) and the lower male die (3).

2. The ferrite bead radial wet pressing mold according to claim 1, wherein: the middle part of the middle die (1) is provided with a transverse through hole (12), a mandrel which is matched with the inner hole of the magnetic ring is movably arranged in the through hole (12), and the mandrel transversely passes through the middle part of the die cavity (11).

3. The ferrite bead radial wet pressing mold according to claim 2, wherein: at least two coaxial cavities (11) are arranged on the middle die (1), and the mandrel penetrates through the adjacent coaxial cavities (11).

4. A ferrite bead radial wet pressing mold according to claim 3, wherein: the front ends of the upper punch (2) and the lower punch (3) are non-magnetic conductive material punches, the rear ends are magnetic conductors of an integrated structure, and the thicknesses of the punches are in transition along the semi-arc-shaped end surface, and the middle of the thickness of the punches is thin, and the thickness of the two ends of the punches is excessive.