阅读说明：本技术 用于制备花边磁钢的模具、取向成型压机及其方法 (Die for preparing lace magnetic steel, orientation forming press and method thereof ) 是由 谢志兴 谢家滨 刘志芳 于 2019-12-27 设计创作，主要内容包括：本发明公开了用于制备花边磁钢的模具、取向成型压机及其方法。该模具包括前侧板、后侧板、左侧板和右侧板；所述前侧板、所述后侧板、所述左侧板和所述右侧板围成一上下开口的型腔；其中,所述左侧板和所述右侧板的材料均为非导磁材料；其中,所述前侧板与所述后侧板靠近型腔一侧的中心区域均为导磁区域,同时除中心区域以外的区域均为不导磁区域；所述导磁区域的宽度与所述型腔的宽度相等,形状与所述花边磁钢相应。本发明制备的花边磁钢,在保证其具有高剩磁(剩磁≥13.5kGs)、质量高(裂纹率低)、磁学性能优异(Hcj≥24kOe、Hcb≥12.5kOe、最大磁能积≥43.5MGOe)的同时,能够简化工序、增加收率,降低成本。(The invention discloses a die for preparing lace magnetic steel, an orientation forming press and a method thereof. The mold comprises a front side plate, a rear side plate, a left side plate and a right side plate; the front side plate, the rear side plate, the left side plate and the right side plate enclose a cavity with an upper opening and a lower opening; the left side plate and the right side plate are made of non-magnetic materials; the central regions of the front side plate and the rear side plate close to the cavity are both magnetic conductive regions, and the regions except the central regions are both non-magnetic conductive regions; the width of the magnetic conduction region is equal to that of the cavity, and the shape of the magnetic conduction region corresponds to that of the lace magnetic steel. The lace magnetic steel prepared by the invention has the advantages of high remanence (the remanence is more than or equal to 13.5kGs), high quality (the crack rate is low), excellent magnetic performance (the Hcj is more than or equal to 24kOe, the Hcb is more than or equal to 12.5kOe, and the maximum magnetic energy product is more than or equal to 43.5MGOe), simplified process, increased yield and reduced cost.)

1. The die for preparing the lace magnetic steel is characterized by comprising a front side plate, a rear side plate, a left side plate and a right side plate;

the front side plate, the rear side plate, the left side plate and the right side plate enclose a cavity with an upper opening and a lower opening;

the left side plate and the right side plate are made of non-magnetic materials;

the central regions of the front side plate and the rear side plate close to the cavity are both magnetic conductive regions, and the regions except the central regions are both non-magnetic conductive regions;

the width of the magnetic conduction region is equal to that of the cavity, and the shape of the magnetic conduction region corresponds to that of the lace magnetic steel.

2. The die of claim 1, wherein the upper edge of the magnetic conducting region has the same shape as the upper edge of the laced magnetic steel, the lower edge of the magnetic conducting region has the same shape as the lower edge of the laced magnetic steel, and the left edge and the right edge of the magnetic conducting region are both linear;

and/or the height of the magnetic conduction area is 2-2.2 times of the height of the pressed compact.

3. The mold according to claim 1, wherein the front plate and the rear plate comprise a magnetic plate having a magnetic portion and a non-magnetic plate having a hollow portion; the magnetic conduction part is nested in the hollow part, so that the magnetic conduction plate is fixed on the non-magnetic conduction plate;

preferably, the magnetic conduction plate is fixed on the non-magnetic conduction plate through 6-8M 6-M8 bolts.

4. The mold of any one of claims 1-3, wherein the laced alnico is neodymium iron boron alnico, samarium cobalt alnico, or ferrite alnico;

the front side plate, the rear side plate, the left side plate and the right side plate are connected through bolts;

preferably, the front side plate and the rear side plate are connected through 3-4M 12-M16 bolts penetrating through the left side plate; the front side plate and the rear side plate are connected through 3-4M 12-M16 bolts penetrating through the right side plate;

the non-magnetic conducting region, the non-magnetic conducting plate, the left side plate, the right side plate or the connecting structure are all made of non-magnetic conducting materials;

preferably, the non-magnetic material is non-magnetic tungsten steel, G60 or 70 Mn;

the magnetic conduction region is made of a magnetic conduction material;

preferably, the magnetic conductive material is 45#, Cr₁₂Pure iron or iron cobalt;

preferably, the left side plate, the right side plate and the non-magnetic conductive plate are provided with a plurality of circular channels parallel to the cavity, and the circular channels are used for installing the die inside the orientation forming press matched with the die.

5. An orientation forming press for making lacework magnetic steel, characterized in that it comprises a die according to any one of claims 1 to 3.

6. The orientation forming press of claim 5, further comprising an upper punch and a lower punch;

preferably, the shape of the surface of the upper punch corresponds to the shape of the upper edge of the laced magnetic steel, and the shape of the surface of the lower punch corresponds to the shape of the lower edge of the laced magnetic steel;

preferably, the upper punch and the lower punch are made of a non-magnetic conductive material;

more preferably, the non-magnetic material is non-magnetic tungsten steel, G60 or 70 Mn.

7. A method for producing a laced magnet steel, characterized in that it uses an orientation forming press according to claim 6, comprising the steps of:

s1, adding magnetic powder into the die to finish powder distribution;

s2, under the condition that coils on two sides of the die are electrified, the upper punch moves downwards, so that the magnetic powder is stacked in the shape of the magnetic conduction area and then is pressed to obtain a pressed blank;

and S3, sintering the pressed compact after reverse demagnetization.

8. The method of claim 7, wherein before step S1, the magnetic field of the orientation forming press is detected, the cavity magnetic field strength is > 16500Gs, and the multipoint detection deviation is < 500 Gs;

and/or in step S1, adding magnetic powder into the mold until the height of the powder is the same as the height of the magnetic conductive region;

and/or, in step S2, the descending speed of the upper punch is 100-300mm/S, for example, 200 mm/S;

and/or in step S2, the coil continuously generates 16000Gs magnetic field after being electrified;

and/or, in step S2, the pressing comprises: after the upper punch head descends to a die assembly position, carrying out floating pressing on the upper punch head and the die;

preferably, the density of the powder body descending to the mold closing position of the upper punch is about 2.23-2.25g/cm³For example, 2.24g/cm³；

Preferably, in the floating pressing, the speed ratio of the upper punch to the die is 1.1-1.3: 1, such as 1.2:1, and the pressing tonnage is 15-20T, such as 18T;

and/or in step S2, maintaining the pressure for 2-5 seconds after the pressing is finished;

and/or in step S2, stopping electrifying the coils at two sides of the die after the pressure maintaining is finished;

and/or in step S3, after the reverse demagnetization, carrying out pressure relief to obtain a pressed compact;

and/or in step S3, the sintering temperature is 1000-1100 ℃;

and/or slicing the lace magnetic steel in a direction perpendicular to the section direction to obtain a plurality of flaky lace magnetic steels;

preferably, the thickness of the sheet-shaped lacework magnetic steel is 1.7-2.1 mm.

9. A lace magnetic steel produced by the production method according to any one of claims 7 to 8.

10. The magnetic lace steel as claimed in claim 9, wherein the remanence of the magnetic lace steel is greater than or equal to 13.5 kGs.

Technical Field

The invention relates to a die for preparing lace magnetic steel, an orientation forming press and a method thereof.

Background

In the actual use process of the motor, the fact that demagnetization currents borne by four corners of the square magnetic steel are large is found, and demagnetization is easy. If four corners of the square-sheet-shaped magnetic steel can be eliminated and the magnet with higher remanence is adopted, the effects of improving the demagnetization resistance and reducing the consumption of the raw material of the magnetic steel can be achieved. Therefore, the special-shaped sheet magnetic steel product lacking four corners needs to be produced.

Disclosure of Invention

The invention aims to solve the technical problems that cracks are easy to generate and the remanence is low when a special-shaped die is used for producing special-shaped products in the prior art, and provides a die for preparing lace magnetic steel, an orientation forming press and a method thereof. The invention ensures that the prepared lace magnetic steel has high remanence (the remanence is more than or equal to 13.5kGs) and high quality, and can simplify the process, increase the yield and reduce the cost.

The invention solves the technical problems through the following technical scheme.

The invention provides a die for preparing lace magnetic steel, which is characterized by comprising a front side plate, a rear side plate, a left side plate and a right side plate;

the front side plate, the rear side plate, the left side plate and the right side plate enclose a cavity with an upper opening and a lower opening;

the left side plate and the right side plate are made of non-magnetic materials;

the central regions of the front side plate and the rear side plate close to the cavity are both magnetic conductive regions, and the regions except the central regions are both non-magnetic conductive regions;

the width of the magnetic conduction region is equal to that of the cavity, and the shape of the magnetic conduction region corresponds to that of the lace magnetic steel.

In the present invention, the lacework magnetic steel may be a magnetic steel having ferromagnetic anisotropy, which is conventional in the art. Preferably, the lace magnetic steel is neodymium iron boron magnetic steel, samarium cobalt magnetic steel or ferrite magnetic steel.

In the present invention, the connection manner of the front side plate, the rear side plate, the left side plate and the right side plate may be a conventional connection manner in the art. Preferably, the front side plate, the rear side plate, the left side plate and the right side plate are connected by bolts. Preferably, the front side plate and the rear side plate are connected through 3-4M 12-M16 bolts penetrating through the left side plate; the front side plate and the rear side plate are connected through 3-4M 12-M16 bolts penetrating through the right side plate.

In the invention, when the die is used, a person skilled in the art knows that when the lace magnetic steel is prepared, coils can be arranged on two sides of the magnetic conduction region, and are used for electrifying to generate a magnetic field after magnetic powder is added into the die to finish powder distribution, so that the magnetic powder is rearranged and oriented to form powder distribution with the shape consistent with that of the magnetic conduction region.

Preferably, the shape of the upper edge of the magnetic conduction region is the same as that of the upper edge of the lace magnetic steel, the shape of the lower edge of the magnetic conduction region is the same as that of the lower edge of the lace magnetic steel, and the left edge and the right edge of the magnetic conduction region are both linear.

Preferably, the height of the magnetic conduction area is 2-2.2 times of the height of the pressed compact. The height of the compact is known to the person skilled in the art to be the height of the body after compression moulding. In the present invention, the inventors have found that, when the height of the loose powder after powder distribution is equal to the height of the magnetic conductive region in the production of the above-mentioned laced magnetic steel, the compact obtained after pressing can have an appropriate density.

As known to those skilled in the art, the magnetic conductive region and the non-magnetic conductive region are located on the same plane, and form a cavity with a smooth surface and an upper opening and a lower opening.

In the present invention, in order to better fix the magnetic conductive region and the non-magnetic conductive region, the front side plate and the rear side plate preferably include a magnetic conductive plate having a magnetic conductive portion and a non-magnetic conductive plate having a hollow portion; the magnetic conduction part is nested in the hollow part, so that the magnetic conduction plate is fixed on the non-magnetic conduction plate.

Preferably, the magnetic conduction plate is fixed on the non-magnetic conduction plate through 6-8M 6-M8 bolts.

Preferably, the left side plate, the right side plate and the non-magnetic conductive plate are provided with a plurality of circular channels parallel to the cavity, and the circular channels are used for installing the die in the orientation forming press matched with the die.

In the invention, after seeing the technical scheme of the invention, a person skilled in the art can know that when the magnetic conduction plate is fixed on the non-magnetic conduction plate by using the bolt, the magnetic conduction part can be fixed on the non-magnetic conduction plate in a nesting manner. Therefore, the effect of magnetic conduction board and fretwork portion lies in: on one hand, the magnetic conduction part can be fixedly nested on the non-magnetic conduction plate; on the other hand, the positioning function can be realized, and the side of the magnetic conduction part close to the cavity and the side of the non-magnetic conduction plate close to the cavity are ensured to be positioned on the same plane; in addition, the design of the magnetic conduction plate can also play a role in strengthening the magnetic field and restraining the magnetism.

In the present invention, as will be understood by those skilled in the art after viewing the technical solutions of the present invention, the width, height and shape of the magnetic conductive part are the same as those of the magnetic conductive region.

In the present invention, after seeing the technical solution of the present invention, a person skilled in the art can know that the non-magnetic conductive region, the non-magnetic conductive plate, the left side plate, the right side plate and the connecting structure are all made of non-magnetic conductive material. Preferably, the non-magnetic material is non-magnetic tungsten steel, G60 or 70 Mn.

In the present invention, after seeing the technical solution of the present invention, a person skilled in the art can know that the magnetic conductive plate or the magnetic conductive region is made of a magnetic conductive material. Preferably, the magnetic conductive material is 45#, Cr₁₂Pure iron or iron cobalt.

In the invention, after seeing the technical scheme of the invention, a person skilled in the art can know that when the die is used for preparing the lace magnetic steel, the die is required to be matched with an orientation forming press for use, and in order to obtain the lace magnetic steel with a target structure, an upper punch and a lower punch of the orientation forming press are required to be designed corresponding to the shape of the lace magnetic steel. Preferably, the upper punch surface has a shape corresponding to the upper edge of the lacework magnetic steel, and the lower punch surface has a shape corresponding to the lower edge of the lacework magnetic steel.

The invention also provides an orientation forming press for preparing the lace magnetic steel, which is characterized by comprising the die.

Preferably, the orientation forming press further comprises the upper punch and the lower punch.

Preferably, the upper punch and the lower punch are made of a non-magnetic conductive material.

More preferably, the non-magnetic material is non-magnetic tungsten steel, G60 or 70 Mn.

The invention also provides a method for preparing the lace magnetic steel, which uses the orientation forming press as described above and comprises the following steps:

s1, adding magnetic powder into the die to finish powder distribution;

s2, under the condition that coils on two sides of the die are electrified, the upper punch moves downwards, so that the magnetic powder is stacked in the shape of the magnetic conduction area and then is pressed to obtain a pressed blank;

and S3, sintering the pressed compact after reverse demagnetization.

Preferably, before step S1, the magnetic field of the orientation forming press is detected, the magnetic field strength of the cavity is more than 16500Gs, and the multipoint detection deviation is less than 500 Gs.

In step S1, as will be known to those skilled in the art after viewing the technical solution of the present invention, before powder is distributed, the die needs to be lowered until the lower edge of the magnetic conductive region is flush with the surface of the lower punch, and the amount of added magnetic powder needs to be matched with the lacework magnetic steel.

In step S1, preferably, magnetic powder is added to the mold until the height of the powder is the same as the height of the magnetic conductive region.

In step S2, as will be known to those skilled in the art after viewing the technical solution of the present invention, the upper punch needs to move down to a mold clamping position, and the mold clamping position needs to be matched with the lacework magnetic steel of the target structure.

In step S2, the coils on both sides of the mold are energized to generate magnetic fields. At this time, the magnetic induction lines around the magnetic field are gathered to the magnetic field region (the magnetic field of the magnetic material is restricted), the magnetic induction lines in the magnetic field region are vertically injected, and the magnetic induction lines outside the magnetic field region are injected at a certain angle. Therefore, the quantity of the magnetic induction lines passing through the magnetic conduction region is far greater than that of other parts, and the magnetic induction lines are obviously gathered, so that the magnetic field intensity of the magnetic conduction region is higher than that of other parts. After the magnetic induction lines enter the cavity from the magnetic conduction region, the magnetic field intensity of the part between the magnetic conduction regions of the front side plate and the rear side plate is strongest, the magnetic powder is rearranged and oriented, the magnetic powder moves to the region with high magnetic field intensity, and finally powder distribution with the shape consistent with that of the magnetic conduction region is formed. Therefore, even if the upper punch moves downwards at a high speed, the compact can be guaranteed to crack due to uneven density of magnetic powder in the pressing process, and the compact with low crack rate and consistent orientation can be obtained, so that a product with high remanence and high quality can be obtained after demagnetization and sintering.

Preferably, in step S2, the descending speed of the upper punch is 100-300mm/S, such as 200 mm/S.

Preferably, in step S2, the coil is powered on to generate 16000Gs magnetic field continuously.

Preferably, in step S2, the pressing includes: and after the upper punch head descends to a die assembly position, carrying out floating pressing on the upper punch head and the die.

Preferably, the density of the powder body descending to the mold closing position of the upper punch is about 2.23-2.25g/cm³For example, 2.24g/cm³。

Preferably, in the floating pressing, the speed ratio of the upper punch to the die is 1.1-1.3: 1, such as 1.2:1, and the pressing tonnage is 15-20T, such as 18T.

In step S2, as known to those skilled in the art, the pressing is completed after pressing to a set size, and pressure holding may be performed after the pressing is completed. Preferably, the pressure is maintained for 2-5 seconds after the pressing is completed.

Preferably, in step S2, the energization of the coils on both sides of the mold is stopped after the pressure holding is completed.

Preferably, in step S3, after the reverse demagnetization, pressure relief is performed to obtain a compact.

Preferably, in step S3, the sintering temperature is 1000-1100 ℃.

The lace magnetic steel can be obtained after sintering, as known by the person skilled in the art. Preferably, the lace magnetic steel is sliced in a direction perpendicular to the cross section to obtain a plurality of flaky lace magnetic steels.

More preferably, the thickness of the sheet-shaped lacework magnetic steel is 1.7-2.1 mm.

The invention also provides the lace magnetic steel which is characterized by being prepared by the preparation method.

Preferably, the remanence of the lace magnetic steel is more than or equal to 13.5 kGs.

On the basis of the common knowledge in the field, the above preferred conditions can be combined randomly to obtain the preferred embodiments of the invention.

The reagents and starting materials used in the present invention are commercially available.

The positive progress effects of the invention are as follows:

in the invention, the central areas of the front side plate and the rear side plate of the mould close to the side of the cavity are both magnetic conductive areas, and the areas except the central areas are both non-magnetic conductive areas; when the lace magnetic steel is prepared, the coils on the two sides of the die are electrified, so that the magnetic powder is rearranged and oriented, and the crack rate caused by uneven density of the magnetic powder generated in the pressing process is greatly reduced; meanwhile, the lace magnetic steel prepared by using the upper punch and the lower punch which are matched with the die and have an arc shape or a plane (but not limited to an arc shape or a plane) can simplify the process, increase the yield and reduce the cost while ensuring that the lace magnetic steel has high residual magnetism (the residual magnetism is more than or equal to 13.5kGs), high quality (the crack rate is low) and excellent magnetic performance (the Hcj is more than or equal to 24kOe, the Hcb is more than or equal to 12.5kOe and the maximum magnetic energy product is more than or equal to 43.5 MGOe).

Drawings

Fig. 1 is a schematic view of a tile-shaped product with a small radian (the distance between the highest point and the lowest point in the height direction of the special-shaped surface of the green compact is less than 8 mm).

Fig. 2 is a schematic view of the lace magnetic steel of embodiment 1.

Fig. 3 is a schematic view of the lace magnetic steel of embodiment 2.

Fig. 4 is a schematic view of the lace magnetic steel of embodiment 3.

FIG. 5 is a schematic view of the magnetic induction lines of the coils on both sides of the mold after being energized in the manufacturing process of example 1.

FIG. 6 is a schematic diagram showing the magnetic powder accumulation changes before and after energizing the coils on both sides of the mold in the manufacturing process of example 1.

Fig. 7 is a schematic view of the lace magnetic steel of embodiment 1.

Fig. 8 is a schematic view of the lace magnetic steel of embodiment 2.

Fig. 9 is a schematic view of the lace magnetic steel of embodiment 3.

Fig. 10 is a schematic view showing the positional relationship of the assembled die, upper punch and lower punch of example 1. Fig. 11 is a schematic view of the assembled mold of example 1.

Fig. 12 is a schematic rear side plate of embodiment 1.

Fig. 13 is a schematic view of a magnetic conductive plate according to embodiment 1.

Fig. 14 is a schematic view of a non-magnetic conductive plate according to embodiment 1.

Fig. 15 is a schematic view of the left side plate of embodiment 1.

Fig. 16 is a schematic view of the upper punch of embodiment 1.

Fig. 17 is a schematic view of a lower punch of example 1.

Description of the reference numerals

Die 1

Front side plate 2

Rear side plate 3

Left side plate 4

Right side plate 5

Die cavity 6

Magnetic conductive region 7

Non-magnetic conductive region 8

M13 bolted connection 9

Magnetic conductive part 71

Magnetic conductive plate 72

Hollow part 81

Non-magnetic conductive plate 82

M7 bolted connection 10

Circular channel 11

Upper punch 12

Lower punch 13

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions.