Small-size samarium cobalt compact forming die

Abstract

The utility model discloses a small-size samarium-cobalt compact forming die, and belongs to the field of manufacturing of samarium-cobalt permanent magnet materials. The die comprises a female die with a cavity, a sawtooth-shaped upper pressure head and a sawtooth-shaped lower pressure head, the cross section of the female mold cavity is a rectangle with a large upper part and a small lower part (the demolding inclination is 0.1-3 degrees), and the female mold cavity is enclosed by left and right magnetic conductive side plates and front and rear non-magnetic conductive side plates; the upper pressing head and the lower pressing head can move in the cavity, and a plurality of identical cuboid forming material cavities are defined by the upper pressing head and the lower pressing head and the cavity during mold closing. Through the design of the multiple material cavities, a plurality of pressed blanks can be formed at a time, and the forming efficiency is improved; the problem of difficult filling is solved by increasing the sectional area of the cavity; the magnetic conductive-non-magnetic conductive structure gathers a magnetic field, so that the magnetic performance of the pressed blank is ensured. The number and the shape of sawteeth of the mold are adjustable, and the mold is suitable for pressing blanks of various specifications, convenient to maintain and suitable for batch production of small-size samarium-cobalt permanent magnet products.

Description

TECHNICAL FIELD

[0001] The utility model belongs to samarium cobalt permanent magnet material manufacturing technical field relates to a kind of small volume samarium cobalt compact forming die. BACKGROUND

[0002] Samarium cobalt permanent magnet material is widely used in national defense military industry, aerospace, microwave device, high-end motor and other fields due to excellent high-temperature magnetic properties and magnetic stability, and samarium cobalt product in square sheet shape accounts for a high proportion in magnetic sensor and permanent magnet motor. At present, the production process of square sheet-shaped samarium cobalt product is usually as follows: first, a large-size square blank is prepared, and then it is processed into the final size by three times of slicing. However, slicing processing has the problems of high cost and low efficiency, which leads to the increase of product production cost and the extension of production cycle.

[0003] To solve the above problems, the industry adopts the "small volume blank design" scheme: for example, for a finished product of 15mm×15mm×2mm (magnetization direction 2mm), the blank is designed as 15.6mm×15.6mm×41mm (magnetization direction 41mm), and the 15.6mm direction is trimmed to 15mm by double-end-face grinding, and then the 41mm direction is sliced into 2mm finished product. Since the efficiency and cost of double-end-face grinding are much better than slicing, this scheme can reduce cost and shorten cycle. However, this scheme requires a small-size forming die, and the existing die has two major problems: (1) difficult to fill: the die cavity corresponding to the small volume blank has a small cross-sectional area, and it is difficult for samarium cobalt powder to be uniformly filled in the cavity, which may lead to uneven density of the compact and fluctuation of magnetic properties. (2) low forming efficiency: the traditional die can only form one compact at a time, which cannot meet the batch production demand.

[0004] The prior art such as CN103447527A guides the magnetic field by a soft magnetic material block, CN104139183A reduces cracks by using an openable and closable inner mold, and CN207731801U improves the magnetic distribution by a magnet plate, but none of them can solve the two technical problems of "difficult to fill" and "low forming efficiency" of small volume samarium cobalt compact. Therefore, there is an urgent need for a forming die suitable for small volume samarium cobalt compact forming, which can improve the forming efficiency and facilitate filling. SUMMARY

[0005] The utility model aims at overcoming the defects of the existing small volume samarium cobalt compact forming die, and provides a die which can simultaneously realize convenient filling and one-time forming of multiple compacts, and the specific technical scheme is as follows.

[0006] A small volume samarium cobalt compact forming die, comprising:

[0007] A female die has a cavity through in the vertical direction, the cross section of the cavity is rectangular, and the cavity is provided with a demolding slope;

[0008] An upper press head, a lower end of the upper press head is inserted into an upper opening of the cavity and is movable up and down in the cavity, and an end face of the lower end of the upper press head is sawtooth-shaped;

[0009] A lower press head, an upper end of the lower press head is inserted into a lower opening of the cavity and is movable up and down in the cavity, and an end face of the upper end of the lower press head is sawtooth-shaped;

[0010] When the lower end of the upper press head and the upper end of the lower press head are close to each other and the mold is closed, the lower end of the upper press head, the upper end of the lower press head and the cavity of the female mold together form a plurality of identical cuboid forming cavities.

[0011] The small-volume samarium-cobalt compact forming die provided by the utility model realizes the one-time forming of a plurality of small-volume samarium-cobalt compacts by the sawtooth-shaped upper and lower press heads and the female mold cavity combination, solves the efficiency problem that the traditional die can only form one compact at a time, and provides a basis for subsequent demolding by the structure cooperation of the large upper part and the small lower part of the cavity and the demolding slope, simultaneously increases the cross-sectional area of the cavity, and solves the problem of difficult filling of the small cavity.

[0012] Further, the demolding slope ranges from 0.1° to 3°. By limiting the demolding slope interval, the compact is prevented from being stuck in the mold and damaged during demolding when the slope is too small, and the compact size deviation is prevented from being too large when the slope is too large, so that the balance between demolding smoothness and compact size precision is ensured.

[0013] Further, the female mold is enclosed by a left side plate, a right side plate, a front side plate and a rear side plate; the left side plate and the right side plate are made of magnetic conductive material and are used for contacting left and right electromagnetic pole heads of a press, respectively; and the front side plate and the rear side plate are made of non-magnetic conductive material. The left side plate and the right side plate guide the magnetic field lines of the electromagnetic pole heads to pass through the forming cavity, the front side plate and the rear side plate limit the magnetic field path, avoid the magnetic field lines from diverging outward, concentrate the magnetic field in the cavity, improve the magnetic orientation degree of samarium-cobalt powder and ensure the magnetic performance of the compact.

[0014] Further, the upper press head and the lower press head are both made of non-magnetic conductive material. The upper and lower press heads made of non-magnetic conductive material further block the magnetic field lines from diverging in the direction of the press head, cooperate with the magnetic conductive-non-magnetic conductive structure of the female mold to form a closed magnetic field concentration channel, further improve the uniformity of the magnetic field strength in the cavity and optimize the magnetic orientation effect.

[0015] Further, an upper end of the upper press head is provided with an upper connecting head, and a lower end of the lower press head is provided with a lower connecting head; the upper connecting head and the lower connecting head are connected with upper and lower connecting rods of a press, respectively.

[0016] Further, the number of the cuboid forming cavities is 2-10, which can be adjusted according to the number of compacts to be formed at a time.

[0017] Further, the shape of the serrated end surface matches the cross-sectional shape of the compact, and the serrated shape of the lower end of the upper punch and the serrated shape of the upper end of the lower punch can be adjusted according to the shape specification of the compact. The serrated shape is adapted to the compact specification (such as different tooth shapes corresponding to square and rectangular compacts), so that the mold can produce small-size samarium-cobalt compacts of various shape specifications, expand the application range of the mold, and meet the diversified product demand.

[0018] Further, the cross section of the cavity is large at the top and small at the bottom, which ensures smooth demolding and avoids damage to the compact during demolding.

[0019] Further, after the upper punch and the lower punch are closed, the minimum gap between the serrations of the two is 0.1mm-1mm. The appropriate minimum gap interval can prevent the serrations of the upper and lower punches from colliding and damaging the mold when the gap is too small, and can prevent the leakage of powder in the cavity or the appearance of gaps in the compact when the gap is too large.

[0020] Further, the connection between the left side plate and the front side plate and the rear side plate, and the connection between the right side plate and the front side plate and the rear side plate are fixed by bolts.

[0021] Compared with the prior art, the mold has the following beneficial effects: (1) improving the molding efficiency: a plurality of compacts can be formed by one-time mold closing, the molding efficiency is several times higher than that of the traditional mold, and the batch production demand is met. (2) optimizing the filling effect: the cross-sectional area of the cavity is several times larger than that of the traditional small cavity, and the powder filling is more convenient. (3) guaranteeing the magnetic performance: the magnetic side plates (left side plate and right side plate) guide the magnetic field, and the non-magnetic side plates (front side plate and rear side plate) block the magnetic field divergence with the punches, so that the uniformity of the magnetic field strength in the cavity and the magnetic orientation degree of the compact are improved. (4) high universality and maintainability: the number and shape of the serrations can be adjusted to adapt to various compact specifications; the side plates are fixed by bolts, and the worn parts can be easily replaced. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a schematic diagram of the overall structure of the mold provided by the utility model.

[0023] Figure 2 is a sectional view of the mold provided by the utility model.

[0024] Figure 3 is a schematic diagram of the upper punch structure.

[0025] Figure 4 is a schematic diagram of the lower punch structure.

[0026] Figure 5 is a schematic diagram of the cavity in the mold closing state.

[0027] Figure 6 is a sectional view of a traditional single-cavity mold.

[0028] Figure 7 is a schematic view of a traditional single-cavity mold cavity.

[0029] Reference signs: 1-rear side plate; 2-upper connecting head; 3-upper pressing head; 4-front side plate; 5-molding cavity; 6-lower pressing head; 7-lower connecting head; 8-left side plate; 9-right side plate. DETAILED DESCRIPTION

[0030] The technical solutions of the present application will be described clearly and completely below in conjunction with the accompanying drawings of the specification. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0031] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or quantity or position.

[0032] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0033] A small-volume samarium-cobalt compact forming mold, as shown in Figure 1 and Figure 2 includes a female mold, an upper pressing head 3 and a lower pressing head 6, and the specific structure is as follows:

[0034] The female mold is formed by the left side plate 8, the right side plate 9, the front side plate 4, and the rear side plate 1, and has a cavity penetrating in the vertical direction, and the cavity has a cross section in the shape of a rectangle with a large upper part and a small lower part, and the demolding slope can be adjusted at 0.1°-3° (for example, for a 15.6mmx15.6mmx41mm blank, the upper edge of the cavity is set to 16mmx16mm, and the lower edge is set to 15.8mmx15.8mm, and the demolding slope is 0.5°). The left side plate 8 and the right side plate 9 are made of a magnetic conductive material and are used to contact the pole head of the electromagnet of the press and guide the magnetic force line through the cavity; the front side plate 4 and the rear side plate 1 are made of a non-magnetic conductive material and limit the divergence of the magnetic field. The side plates are fixed by bolts, which is convenient for disassembly and maintenance.

[0035] The upper press head 3 (as shown in Figure 3 ) and the lower press head 6 (as shown in Figure 4 ): Both are made of a non-magnetic conductive material to avoid the divergence of the magnetic force line to the press head. The lower end of the upper press head 3 and the upper end of the lower press head 6 are both sawtooth-shaped, and the number of sawteeth can be adjusted according to the number of one-time forming of the blank (for example, 3 groups of sawteeth for 3 blanks per mold), and the shape of the sawteeth is adapted to the size of the blank (for example, square sawteeth for square blanks and rectangular sawteeth for rectangular blanks). The upper end of the upper press head 3 is provided with an upper connecting head 2, and the lower end of the lower press head 6 is provided with a lower connecting head 7, both of which are protruding structures matched with the dovetail groove of the connecting rod of the press, to ensure the movement accuracy.

[0036] The cavity is formed: the upper press head 3 is inserted from the upper part of the cavity, and the lower press head 6 is inserted from the lower part. Both move up and down along the cavity, and the sawteeth are aligned (without misalignment) when the mold is closed, forming a plurality of identical cuboid forming cavities 5 (such as 3 15.6mmx15.6mmx41mm cavities) around the female mold cavity, as shown in Figure 5 . The minimum gap of the sawteeth after the mold is closed is controlled at 0.1mm-1mm (such as 0.5mm).

[0037] The forming process is as follows.

[0038] (1) Mold assembly: the left side plate 8 and the right side plate 9 of the female mold are fixed with the front side plate 4 and the rear side plate 1 by bolts, the upper press head 3 is connected with the upper connecting rod dovetail groove of the press through the upper connecting head 2, and the lower press head 6 is connected with the lower connecting rod of the press through the lower connecting head 7.

[0039] (2) Filling: control the upper press head to go up to the lower part of the cavity, so that the upper part of the cavity is exposed, and samarium-cobalt powder is filled into the cavity. Because the cross-sectional area of the cavity is several times that of the traditional single cavity (as shown in Figure 6 , Figure 7 ), it is more convenient to fill the powder, and the powder is naturally and uniformly distributed.

[0040] (3) Magnetic orientation: start the electromagnet of the press, and the magnetic force line passes through the left side plate→cavity (forming cavity)→right side plate in turn, forming a closed magnetic field to ensure that the powder magnetic crystal orientation is consistent.

[0041] (4) Mould closing and pressing: the upper punch is driven to go down and the lower punch is driven to go up, the mould closing speed is controlled to be 5 mm / s, the pressing pressure is set to be 20 MPa, the pressure maintaining time is 5 s, at this time, the minimum gap of the sawtooth is kept to be 0.5 mm, and the powder is pressed into three green compacts.

[0042] (5) Demoulding and taking out: after the pressing is completed, the upper punch goes up and the lower punch continues to go up, the three green compacts are synchronously pushed out of the cavity by the demoulding slope of the cavity, the lower punch is reset after the green compacts are taken out, and the next cycle is entered.

[0043] Although the embodiments of the utility model have been shown and described above, it can be understood that the above-mentioned embodiments are exemplary and cannot be understood as the limitation of the utility model, and the ordinary skilled in the art can change, modify, replace and transform the above-mentioned embodiments in the range of the utility model without departing from the principles and purposes of the utility model. The protection scope of the utility model is defined by the claims and the equivalent technical solutions.

Claims

1. A small-size samarium-cobalt compacting die, characterized by comprising: The utility model relates to a kind of moulding machine and moulding method, including: Female mould, the female mould has cavity through in vertical direction, the cross section of the cavity is rectangular, the cavity is provided with demoulding slope; Upper pressure head, the lower end of the upper pressure head is inserted by the upper opening of the cavity and can move up and down in cavity, the lower end face of the upper pressure head is jagged; Lower pressure head, the upper end of the lower pressure head is inserted by the lower opening of the cavity and can move up and down in cavity, the upper end face of the lower pressure head is jagged; When the lower end of the upper pressure head and the upper end of the lower pressure head are close to each other and clamped, the lower end of the upper pressure head, the upper end of the lower pressure head and the cavity of the female mould jointly form multiple identical cuboid forming cavities.

2. The small volume samarium-cobalt compacting die of claim 1, wherein, The range of the demoulding slope is 0.1°~3°.

3. The small volume samarium-cobalt compacting die of claim 1, wherein, The female mould is enclosed by left side plate, right side plate, front side plate and rear side plate;The left side plate and right side plate are magnetic conductive material, and are respectively used to contact with the left and right side electromagnet pole head of the press;The front side plate and rear side plate are non-magnetic conductive material.

4. The small volume samarium-cobalt compacting die of claim 1, wherein, The upper pressure head and the lower pressure head are non-magnetic conductive material.

5. The small volume samarium-cobalt compacting die of claim 1, wherein, The upper end of the upper pressure head is provided with upper connector, and the lower end of the lower pressure head is provided with lower connector;The upper connector and lower connector are connected with upper connecting rod and lower connecting rod of the press respectively.

6. The small volume samarium-cobalt compacting die of claim 1, wherein, The number of the cuboid forming cavities is 2~10.

7. The small volume samarium-cobalt compacting die of claim 1, wherein, The shape of the jagged end face matches the cross-sectional shape of the compact.

8. The small volume samarium-cobalt compacting die of claim 1, wherein, The cross section of the cavity is large on top and small on bottom.

9. The small volume samarium-cobalt compacting die of claim 1, wherein, After the upper pressure head and the lower pressure head are clamped, the minimum gap between the two jagged teeth is 0.1mm~1mm.

10. The small volume samarium-cobalt green compact forming die of claim 3 wherein, The connection of the left side plate and front side plate, rear side plate, and the connection of the right side plate and front side plate, rear side plate are fixed by bolt.

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