CN213997789U - Side-pressing male die forming anisotropic sintered neodymium iron boron die - Google Patents

Abstract

The utility model provides a side pressure terrace die shaping opposite sex sintered neodymium iron boron mould, including the upper die assembly, the lower die assembly, the die and the coil, the upper die assembly includes the upper die plate, the upper sliding block fixed plate and the upper punch, the lower die assembly includes the die plate, the adjusting part and the lower punch, the lower punch with one end extending to the die is matched with the die to form the shaping cavity, the powder to be pressed is located between the upper punch and the lower punch, the upper punch is driven by the press to slide into the shaping cavity to press the powder, the one end of the die far away from the upper punch is equipped with the floating plate, the one end of the floating plate near the upper die plate is equipped with the lower sliding block, the upper sliding block fixed plate is equipped with the upper sliding block matched with the lower sliding block, and a side pressure convex die is arranged on the side surface of the lower sliding block close to the concave die.

Description

Side-pressing male die forming anisotropic sintered neodymium iron boron die

Technical Field

The utility model relates to a neodymium iron boron magnetism body technical field especially relates to a side pressure terrace die shaping opposite sex sintering neodymium iron boron mould.

Background

The Nd-Fe-B rare earth permanent magnet material is divided into bonded Nd-Fe-B and sintered Nd-Fe-B, is applied to the fields of energy, transportation, machinery, medical treatment, household appliances and the like, and generally has a tile shape and a square shape. The conventional sintered Nd-Fe-B rare earth permanent magnet is manufactured by pressing rare earth raw material powder in a die cavity through a male die which is pressed in the vertical direction, orienting magnetic domains of the powder under a magnetic field in the horizontal direction, firstly pressing the powder into a cuboid permanent magnet with parallel magnetic domains in the horizontal direction, cutting the sintered powder into 'magnetic tiles' or square blocks with sector cross sections after sintering, and magnetizing the magnetic tiles. For example, the chinese patent with the application number CN200620021585.6 provides an anisotropic sintered rare earth permanent magnet orientation forming device, and the chinese patent with the application number CN201320599956.9 provides a neodymium iron boron production mold; the above-described magnetic field left-right orientation setting method is introduced.

Because of the high Br and Hcb of the sintered NdFeB in the field of motors, the motor can be designed to be miniaturized and have high power. The thickness of the sintered neodymium iron boron magnetized orientation direction for the motor designed at present is generally 1.6 mm-4 m, the height of the product is 20-45 mm, and a large block formed sintered body is adopted to be cut into a single sintered neodymium iron boron magnetic tile or a square block.

In view of the above forming method, chinese patent No. CN106252054B provides an anisotropic nd-fe-b magnet molding orientation forming apparatus, which includes: the mould assembly is connected with the heating device and is formed by connecting a mould main body with an upper mould main body seat, a lower mould main body seat and an inner sleeve, a mould cavity which is communicated up and down is arranged in the center of the mould assembly, the mould main body comprises a magnetizer and a nonmagnetic body, the magnetizer is provided with an orientation device, the mould main body is detachably connected to a first template, and the first template is fixed on the upper part of the punching machine; the upper stamping part is detachably connected to the lower part of the stamping machine head and can move up and down along with the stamping machine head; the lower stamping part is a tubular body, the lower end of the lower stamping part is detachably connected to the second template, and the upper end of the lower stamping part extends into the die cavity of the die main body; the lower end of the core rod is movably connected with the punch seat, the anisotropic neodymium iron boron magnet prepressing piece to be formed is arranged between the die cavity of the die main body in a heating state and the core rod and falls into the top of the lower punching piece, the upper punching piece is started to move downwards, when the upper punching piece enters the die main body, the orientation device is conducted and carries out magnetic pole orientation, and meanwhile, the upper punching piece continues to move downwards to press and form the neodymium iron boron magnet prepressing piece.

The defects of the patent are that when the size of the pressed oriented compact is too large, the distribution gradient of the oriented magnetic field is different, and the performance consistency of the cut single magnet is poor; moreover, the price of the rare earth is increased, a lot of waste is caused in the cutting process, and the material utilization rate is low. Further, if a design method of pressing and molding a small-size single body in a single cavity is adopted, the following problems can be solved according to the arrangement of the upper pressing male die, the lower pressing male die and the left and right molding magnetic fields: the fine cavity opening is easy to cause the powder to generate a 'bridging effect' at the cavity opening part, and the powder is difficult to be added into the fine cavity of the mold; the high molding height causes a difference in density between the upper and lower layers, and cracking occurs during mold release or mold release is difficult.

Based on the above statements, how to further optimize the orientation press forming method to make it suitable for the sintered anisotropic rare earth permanent magnet green body with thinner thickness dimension is a technical problem to be solved urgently by those skilled in the art.

Disclosure of Invention

The utility model discloses an after overcoming bulky permanent magnet press forming among the prior art, the monolithic magnetite uniformity that forms through the cutting is poor, and the cutting process causes many wastes, and material utilization is lower, and the higher technical problem of manufacturing cost provides a side pressure terrace die shaping opposite sex sintering neodymium iron boron mould, adopts monomer single chamber press forming's processing method, and the uniformity of the magnetite performance after the shaping is excellent, need not cutting process so the utilization ratio of material is higher, and drawing of patterns efficiency is higher.

In order to achieve the above purpose, the present invention adopts the following technical solution.

The utility model provides a side pressure terrace die shaping opposite sex sintering neodymium iron boron mould, includes the mould subassembly, lower mould subassembly, die and coil, goes up the mould subassembly and includes cope match-plate pattern, top shoe fixed plate and upper punch, and lower mould subassembly includes die template, regulating part and lower punch, and the lower punch that one end extends to in the die is the shaping chamber with the die cooperation, treats that the powder of suppression is located between upper punch and the lower punch, and it is right that the upper punch drives the lower shaping chamber that goes into at the press the powder is suppressed, and the one end that the upper punch was kept away from to the die is equipped with the float plate, and the one end that the float plate is close to the cope match-plate pattern is equipped with the lower slider on the upper shoe fixed plate, and the lower slider is close to and is equipped with the side pressure terrace die on the side of die, and the side pressure terrace die drives the lower shaping chamber that goes into right the powder is suppressed, and the magnetic field orientation of coil is unanimous with the axial of die.

The sintered ndfeb usually has tile shape and square shape, and for the convenience of illustration, x direction, y direction and z direction are respectively defined on the sintered anisotropic rare earth ndfeb permanent magnet shown in fig. 1 and 2. In the process of pressing, forming and sintering the special rare earth neodymium iron boron permanent magnet green body, the powder is difficult to be added into a fine cavity of the mold, because the fine cavity easily enables the powder to generate a bridging effect (a macromolecule is adsorbed to connect a plurality of colloidal particles to form a larger aggregate to be gathered) at the cavity opening part, and the forming height (namely the size along the z direction is larger) can cause the density difference of an upper layer and a lower layer, along with the increase of the pressing depth, the friction force between the mold cavity and the powder is exponentially increased, so that the product is demolded and cracked or cannot be formed. Based on the problems, the manufacturing process of the sintered neodymium iron boron magnetic shoe and the thin square block for the field of common motors is as follows: firstly, molding and pressing a die to form a cuboid permanent magnet with horizontal parallel magnetic domains, sintering, then cutting and processing the cuboid permanent magnet into a 'magnetic shoe' or a square block with a sector-shaped cross section, and then magnetizing the square block for use; the thickness of the product is increased along the z direction, and the thickness of the product is generally 15 mm-120 mm by making a die, so that the product can be pressed. The problem is that when the size of the pressed oriented compact is too large, the distribution gradient of the oriented magnetic field is different, so that the performance consistency of the cut single magnet is poor; moreover, the price of the rare earth is increased, a lot of waste is caused in the cutting process, and the material utilization rate is low.

The application provides a side pressing male die forming special-shaped sintered neodymium iron boron die, which can form a single small-size neodymium iron boron green body, the structure of a press is simple, a coil with a magnetic field oriented along the axial direction of a female die is arranged, an upper cylinder of the press generates pressure downwards, a lower sliding block is pushed to move close to the female die when an upper sliding block synchronously downwards moves, a side pressing male die is arranged on the side surface of the lower sliding block close to the female die, the side pressing male die is driven by the lower sliding block to move close to the female die, in order to avoid the width direction deviation of a formed product, the two side pressing male dies are symmetrically arranged along the horizontal direction and press the upper cylinder downwards along with the press, the powder in the die cavity is simultaneously pressed and formed in the horizontal left and right directions, the pressing direction of the lateral pressure convex die is carried out along the z direction defined by the preamble, the filling operation of the powder is carried out along the y direction, the size in the y direction is smaller than that in the z direction, so that the problem of difficult feeding caused by the bridging effect can be effectively solved; in addition, this application the mould is to the suppression operation of powder, both including along the axial last punch pressing action of die, also including the side pressure terrace die pressing action along die width direction, the moulding performance of product is good, can effectively avoid drawing of patterns fracture or unable fashioned technical problem.

Preferably, the lower slider includes passive side, and the upper sliding block includes the drive inclined plane, and the inclination on passive side and drive inclined plane is unanimous and laminating each other, and passive inclined plane is located the lower slider and keeps away from die one side, and the drive inclined plane is located the upper sliding block and is close to die one side. According to the technical scheme, the matching mode of the upper sliding block and the lower sliding block is limited, when the press moves downwards, the driving inclined plane on the upper sliding block synchronously moves downwards, the space for containing the lower sliding block below the upper sliding block is reduced, the lower sliding block is pushed to move towards the female die under the extrusion action of the upper sliding block, the side pressing convex die is arranged on the end face, close to the female die, of the lower sliding block, the side pressing convex die is driven to synchronously move close to the female die when the lower sliding block moves, and the side pressing convex die extends into the female die to press powder along the width direction of the female die.

As preferred, be equipped with the stopper on the terminal surface that the floating plate is close to the cope match-plate pattern, the stopper is located one side that the die was kept away from to the lower slider, and is spacing including spacing section, installation section and bearing segment, and the spacing section of arranging along the floating plate normal direction and the one side butt that the die was kept away from to last slider, the bearing segment level is arranged on the floating plate, is equipped with on the terminal surface that the lower slider is close to the stopper and bears a matched with spout. Lower slider need be close to the die and remove under the drive of last slider, so need keep away from die one side at lower slider and lay the stopper, avoid lower slider landing on the self-floating plate, it is further, for realizing the good direction to lower slider, guarantee that lower slider removes along the width direction of die, stopper in this application is including bearing the section, bear the section be located lower slider below and with the spout phase-match on the lower slider, the width direction of bearing the section along the die arranges, the section of bearing the displacement direction to its displacement action when lower slider is close to the die and removes, take place the skew when avoiding lower slider to remove.

Preferably, the inner wall surface of the female die is provided with an alloy layer, the circumferential surface of the female die is provided with a pressing groove for allowing the side pressing punch to pass through, the pressing groove penetrates in the thickness direction of the alloy layer, and the side pressing punch is provided with a return spring. The wall surface in contact with the powder needs to be made of a high-strength material so as to avoid deformation of the product caused by structural deformation under the action of pressure, but the whole female die is made of the high-strength material at a higher cost, and in order to reduce production cost, an alloy layer is arranged on the inner wall surface of the female die, and the rest parts of the female die can be made of relatively lower materials; the reset spring is used for resetting the lower sliding block, so that the lower sliding block is ensured to return to the initial position before the next pressing action, and the normal operation of the pressing action is ensured.

Preferably, the end face of the upper die plate close to the floating plate is connected with one end of a nitrogen spring, the other end of the nitrogen spring is connected with an upper die fixing plate, and the upper punch is fixed on the end face of the upper die fixing plate far away from the upper die plate. The nitrogen spring is used for generating mold sealing pressure for the upper punch.

Preferably, a plurality of guide pieces are arranged between the upper die plate and the upper die fixing plate at intervals, and each guide piece comprises a guide sleeve and a guide rod which are in sliding fit.

Preferably, the alloy layer is made of nonmagnetic hard alloy material with hardness greater than HRA86, and the alloy layer is embedded in the inner wall of the concave die.

To sum up, the utility model discloses following beneficial effect has: (1) by adopting the processing method of single-body single-cavity compression molding, the consistency of the performance of the molded magnet is excellent, and the utilization rate of the material is higher and the demolding efficiency is higher because cutting processing is not needed; (2) in the application, the powder filling operation is carried out along the y direction, and the size of the y direction is smaller than that of the z direction, so that the problem of difficult feeding caused by a bridging effect can be effectively solved; (3) the product has excellent shaping performance, and can effectively avoid the technical problems of demoulding cracking or incapability of forming; (4) the forming die for preparing the sintered special-shaped neodymium-iron-boron green body has small reserved machining allowance, can obviously reduce material waste, and obviously improves the utilization rate of materials and the magnetic performance of a sintered magnet.

Drawings

Fig. 1 is a tile-shaped schematic view of the sintered anisotropic rare earth neodymium iron boron permanent magnet of the present invention.

Fig. 2 is a schematic diagram of the utility model for preparing sintered anisotropic rare earth neodymium iron boron permanent magnet block.

Fig. 3 is a front view of the forming die for preparing sintered special-shaped rare earth neodymium iron boron permanent magnet green body of the utility model.

Figure 4 is the utility model discloses a preparation sintering opposite sex tombarthite neodymium iron boron permanent magnet unburned bricks mould implements the plan view.

Fig. 5 is a diagram of an embodiment of a mold for forming a green body of a sintered anisotropic rare earth neodymium iron boron permanent magnet.

Fig. 6 is a partially enlarged view of a position a in fig. 3.

In the figure:

the die comprises a female die 1, a coil 2, an upper die plate 3, an upper slide block fixing plate 4, an upper punch 5, a die plate 6, an adjusting part 7, a forming cavity 8, powder 9, a floating plate 10, a lower slide block 11, a driven side surface 11a, a sliding groove 11b, an upper slide block 12, a driving inclined surface 12a, a side pressing male die 13, a limiting block 14, a limiting section 14a, an installation section 14b, a bearing section 14c, an alloy layer 15, a pressing groove 16, a return spring 17, a nitrogen spring 18, an upper die fixing plate 19, a guide part 20, a guide sleeve 20a and a guide rod 20 b.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary only for the purpose of explaining the present invention, and should not be construed as limiting the present invention.

In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on the orientations or positional relationships illustrated in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore, should not be construed as limiting the present invention.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Example (b):

as shown in fig. 1 to fig. 1, the side-pressing convex die forming anisotropic sintered neodymium iron boron die comprises an upper die assembly, a lower die assembly, a concave die 1 and a coil 2, wherein the upper die assembly comprises an upper die plate 3, the powder compacting device comprises an upper slide block fixing plate 4 and an upper punch 5, wherein the lower die assembly comprises a die template 6, an adjusting piece 7 and a lower punch, the lower punch and the female die, one end of the lower punch extends into the female die and is matched with the female die to form a molding cavity 8, powder 9 to be compacted is positioned between the upper punch and the lower punch, the upper punch is driven by the pressing machine to slide into the molding cavity to compact the powder, one end of the female die, which is far away from the upper punch, is provided with a floating plate 10, one end of the floating plate, which is close to the upper template, is provided with a lower slide block 11, the upper slide block fixing plate is provided with an upper slide block 12 matched with the lower slide block, the side surface of the lower slide block, which is close to the female die, is provided with a side pressing convex die 13, the side pressing convex die drives the lower slide block to slide into the molding cavity to compact the powder, and the magnetic field orientation of a coil is consistent with the axial direction of the female die; the lower sliding block comprises a driven side surface 11a, the upper sliding block comprises a driving inclined surface 12a, the driven side surface and the driving inclined surface have the same inclination angle and are mutually attached, the driven inclined surface is positioned on one side of the lower sliding block, which is far away from the female die, and the driving inclined surface is positioned on one side of the upper sliding block, which is close to the female die; the end face, close to the upper template, of the floating plate is provided with a limiting block 14, the limiting block is positioned on one side, away from the female die, of the lower sliding block and comprises a limiting section 14a, a mounting section 14b and a bearing section 14c, the limiting section arranged in the normal direction of the floating plate is abutted against one side, away from the female die, of the upper sliding block, the bearing section is horizontally arranged on the floating plate, and the end face, close to the limiting block, of the lower sliding block is provided with a sliding groove 11b matched with the bearing section; an alloy layer 15 is arranged on the inner wall surface of the female die, a pressure groove 16 allowing the side pressure male die to penetrate through is arranged on the circumferential surface of the female die, the pressure groove is communicated along the thickness direction of the alloy layer, and a return spring 17 is arranged on the side pressure male die; the end face, close to the floating plate, of the upper die plate is connected with one end of a nitrogen spring 18, the other end of the nitrogen spring is connected with an upper die fixing plate 19, and the upper punch is fixed on the end face, far away from the upper die plate, of the upper die fixing plate; a plurality of guide pieces 20 are arranged between the upper die plate and the upper die fixing plate at intervals, and each guide piece comprises a guide sleeve 20a and a guide rod 20b which are in sliding fit; the alloy layer is made of a nonmagnetic hard alloy material with the hardness larger than HRA86, and the alloy layer is embedded in the inner wall of the concave die.

In the embodiment, the hydrogen crushing treatment adopts an HD hydrogen crushing process; the strong magnetic field orientation forming technology is adopted when the magnetic field orientation is carried out; the sintering process adopts a full-sealed high-vacuum gas quenching sintering process when sintering is carried out in a vacuum sintering furnace.

As shown in fig. 3, the top is an upper mold plate, an upper slide fixing plate is arranged below the upper mold plate, an upper slide block is connected to the lower end surface of the upper mold plate, the structure is described by taking the upper slide block positioned on the right side of a female mold as an example, the upper slide block comprises a driving inclined surface positioned on the left side, the driving inclined surface inclines downwards from left to right, a lower slide block is arranged below the upper slide block, a driven side surface is arranged on the right side of the lower slide block, the driven side surface inclines downwards from left to right, the driving inclined surface is in contact fit with the driven side surface, a limiting block is arranged on the right side of the lower slide block, a floating plate is arranged below the lower slide block, the limiting block comprises a limiting section and an installation section which are vertically arranged, the installation section is connected with the side surface of the floating plate, the limiting section is abutted against the right side surface of the upper slide block, the bearing section is horizontally arranged on the floating plate, and a chute matched with the bearing section is arranged on the lower end surface of the lower slide block, when the upper sliding block moves downwards, the lower sliding block is extruded to move leftwards synchronously, the upper sliding block and the lower sliding block are also arranged on the left side of the female die, and the upper sliding block and the lower sliding block on the left side of the female die are symmetrical to the structure. The concave die is arranged at the central position of the floating plate, an alloy layer is arranged on the inner wall surface of the concave die, the alloy layer is made of nonmagnetic hard alloy materials with the hardness larger than HRA86, a pressing groove is arranged on the circumferential surface of the concave die, the pressing groove penetrates to the powder position along the wall thickness direction of the concave die, a side pressing convex die can extend into the pressing groove and press the powder, and when the upper sliding block is driven by the upward movement of the press to move synchronously upwards, the lower sliding block moves towards the direction far away from the concave die under the drive of the reset spring to prepare for the next pressing action.

As shown in fig. 4, in this embodiment, the female die is provided with two forming cavities, the forming cavities are long, the length direction of the forming cavities is arranged along the moving direction of the lateral pressing male die, and the inner wall of the female die is embedded with an alloy layer made of a nonmagnetic hard alloy material with hardness greater than HRA 86. As shown in FIG. 5, in order to lead the upper sliding block to move downwards by the press, the nitrogen spring is designed, the nitrogen spring generates mold sealing pressure for the upper punch, the lower sliding block and the upper sliding block are mutually wedged and linked, after the mold is sealed, the upper punch stops moving downwards under the resistance of the female mold and compresses the nitrogen spring, the upper sliding block continues moving downwards, the lower sliding block is guided and matched to move in the horizontal direction to press the side pressing male mold, and powder filled in the female mold is pressed and molded under the pressure of the side pressing male mold. The female die and the like are fixed on the floating plate, and the limiting block limits the upper sliding block fixing plate to descend in a controllable range. The molding environment needs to be operated under the condition of being filled with nitrogen and the like and isolating oxygen, which is particularly important in the production of the high-performance neodymium iron boron rare earth permanent magnet which is easy to oxidize. After the upper cylinder moves to a set stroke and the side pressure male die is pressurized, removing the orientation magnetic field and applying a reverse magnetic field for demagnetization; controlling the upper cylinder to reset quickly; and after the side pressing male die is withdrawn to the original position, the floating plate is pulled down under the action of the lower cylinder of the press, the female die is pulled down simultaneously, and the lower punch is fixed, so that the neodymium iron boron green body is ejected out.

Claims (7)

1. The utility model provides a side pressure terrace die shaping opposite sex sintering neodymium iron boron mould, includes the mould subassembly, lower mould subassembly, die and coil, its characterized in that, it includes cope match-plate pattern, upper slide fixed plate and upper punch to go up the mould subassembly, and lower mould subassembly includes mould template, regulating part and lower punch, and the lower punch that one end extends to in the die is for the shaping chamber with the die cooperation, and the powder of treating the suppression is located between upper punch and the lower punch, and it is right that the upper punch drives down the shaping chamber under the press the powder is suppressed, and the one end that the upper punch was kept away from to the die is equipped with the float plate, and the one end that the float plate is close to the cope match is equipped with the lower slider on the upper slide fixed plate, and the lower slider is close to and is equipped with the side pressure terrace die on the side of die, and the side pressure terrace die drives down the shaping chamber right under the lower slider the powder is suppressed, and the magnetic field orientation of coil is unanimous with the axial of die.

2. The side-pressing punch molding anisotropic sintered neodymium-iron-boron die is characterized in that the lower sliding block comprises a driven side face, the upper sliding block comprises a driving inclined face, the driven side face and the driving inclined face are consistent in inclination angle and are attached to each other, the driven inclined face is located on the side, away from the female die, of the lower sliding block, and the driving inclined face is located on the side, close to the female die, of the upper sliding block.

3. The side-pressing male die forming anisotropic sintered neodymium-iron-boron die is characterized in that a limiting block is arranged on the end face, close to the upper die plate, of the floating plate, the limiting block is located on one side, away from the female die, of the lower sliding block, the limiting block comprises a limiting section, a mounting section and a bearing section, the limiting section arranged in the normal direction of the floating plate is abutted to one side, away from the female die, of the upper sliding block, the bearing section is horizontally arranged on the floating plate, and a sliding groove matched with the bearing section is formed in the end face, close to the limiting block, of the lower sliding block.

4. The special sintered NdFeB die for molding the side pressing male die according to claim 3, wherein an alloy layer is arranged on the inner wall surface of the female die, a pressing groove allowing the side pressing male die to penetrate through is arranged on the peripheral surface of the female die, the pressing groove penetrates through the thickness direction of the alloy layer, and a return spring is arranged on the side pressing male die.

5. The side-pressing male die forming special-shaped sintered neodymium-iron-boron die as claimed in claim 1, 2 or 3, wherein one end of the nitrogen spring is connected to the end face of the upper die plate close to the floating plate, the other end of the nitrogen spring is connected to the upper die fixing plate, and the upper punch is fixed to the end face of the upper die fixing plate far away from the upper die plate.

6. The side-pressing punch forming special-shaped sintered neodymium-iron-boron die as claimed in claim 5, wherein a plurality of guide members are arranged between the upper die plate and the upper die fixing plate at intervals, and each guide member comprises a guide sleeve and a guide rod which are in sliding fit.

7. The side-pressing punch molding anisotropic sintered neodymium-iron-boron die as claimed in claim 4, wherein the alloy layer is made of a nonmagnetic hard alloy material with hardness greater than HRA86, and the alloy layer is embedded in the inner wall of the female die.

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