All-electric radiation ring magnetic field forming press

Abstract

The invention discloses a full-electric radiation ring magnetic field forming press which comprises a sealing box body, a powder weighing device, a feeding device and a forming device are arranged in the sealing box body, a mold is fixedly connected to a rack through a concentrating flux plate, an upper guide plate is arranged at the upper end of the concentrating flux plate and can vertically move under the action of an upper electric cylinder, and a lower guide plate is arranged at the lower end of the concentrating flux plate. The upper electromagnet assembly is connected to the upper guide plate, the upper punch is connected to the lower end of the upper electromagnet assembly, the lower guide plate is arranged at the lower end of the magnetic conductive plate and can vertically move under the action of the lower electric cylinder, the lower electromagnet assembly is fixedly connected to the lower guide plate, and the lower punch is fixedly connected to the upper end of the lower electromagnet assembly. The upper electromagnet assembly and the lower electromagnet assembly are matched for magnetizing, the core rod is arranged in the middle of the rack and can stretch out and draw back along a die cavity of the die under the action of the core pulling electric cylinder, the lower die punch stretches into the die cavity of the die, and the lower die punch, the core rod and the die cavity form an annular cavity used for being filled with neodymium iron boron powder. More uniform magnetizing density and higher magnetizing intensity are effectively ensured.

Description

Technical Field

[0001] The invention relates to the technical field of NdFeB magnet processing devices, and in particular to a full-electric radiation ring magnetic field forming press. Background Art

[0002] The magnetic field forming press mainly includes a sealed frame, in which a powder weighing device, a feeding device and a forming device are installed. The NdFeB powder first enters the powder weighing device through a barrel, and the powder weighing device weighs a certain amount of NdFeB powder and then loads it into the feeding device. Finally, the feeding device pushes it to the forming device, and the NdFeB powder is loaded into a forming mold, and then the NdFeB powder is pressed and formed.

[0003] In the existing fully automatic radiation ring magnetic field forming press, such as the fully automatic radiation ring floating magnetic field forming press disclosed in the Chinese patent (application publication number CN108247046A), the NdFeB powder is magnetized by the magnetic field coil on the rear side of the frame during the pressing process. In order to make the magnetization amount of each part of the NdFeB magnet equivalent, the forming mold is rotated to make the NdFeB powder rotate equivalent to the magnetic field coil, so that the distance between the NdFeB powder in the forming mold and the magnetic field coil is the same, so that the magnetic distribution of the radiation ring after molding is uniform. However, it usually takes a certain amount of time from the time the magnetic field coil starts to be energized to the time when the magnetic field coil reaches the required magnetic field strength. During this process, the magnetic field coil will also magnetize the NdFeB powder. Compared with the amount of magnetization required to reach a stable magnetic field strength, this will cause inconsistent magnetization density of the NdFeB powder. Specifically, the pressed NdFeB powder has a large density difference in the blank because the magnetic field direction and the forming direction are perpendicular, which can easily cause stress cracking during the sintering process and a large magnetic deflection angle, thereby generating waste. In addition, the existing magnetic field forming press is prone to magnetic leakage during the magnetization process, and the magnetic field strength cannot be guaranteed. Summary of the invention

[0004] The purpose of the present invention is to provide a fully electric radiation ring magnetic field forming press, in which the upper electromagnet assembly and the lower electromagnet assembly are longitudinally arranged in the frame, effectively ensuring that the magnetization density is more uniform and the magnetization intensity is higher.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions: a fully electric radiation ring magnetic field forming press, including a sealed box, a powder weighing device, a feeding device and a forming device are installed in the sealed box, the forming device includes a frame, an upper guide plate, an upper electromagnet assembly, an upper die punch, an upper electric cylinder, a mold, a lower guide plate, a lower electromagnet assembly, a lower die punch, a lower electric cylinder, a core rod and a core-pulling electric cylinder, the mold is fixedly connected to the frame through a magnetic conductive plate, the upper guide plate is arranged on the upper end of the magnetic conductive plate and can move vertically under the action of the upper electric cylinder, the upper electromagnet assembly is fixedly connected to the upper guide plate, the upper die punch It is fixedly connected to the lower end of the upper electromagnet assembly, the lower guide plate is arranged at the lower end of the magnetic conductive plate and can move vertically under the action of the lower electric cylinder, the lower electromagnet assembly is fixedly connected to the lower guide plate, the lower die punch is fixedly connected to the upper end of the lower electromagnet assembly, the upper electromagnet assembly and the lower electromagnet assembly cooperate in magnetization, the core rod is arranged in the middle of the frame, the core rod can be extended and retracted along the mold cavity of the mold under the action of the core-pulling electric cylinder, the lower die punch extends into the mold cavity of the mold, the lower die punch, the core rod and the mold cavity form an annular cavity for filling NdFeB powder, and the quantitative NdFeB powder weighed by the powder weighing device is transferred to the annular cavity through the feeding device.

[0006] Furthermore, the upper electromagnet assembly includes an upper pole fixed to the upper guide plate, an upper pole head fixed to the lower end of the upper pole, and an upper electromagnetic coil fixed to the outer periphery of the upper pole, the upper punch is fixed to the lower end of the upper pole head, the upper electric cylinder is fixedly installed on the top of the frame, and the output end of the upper electric cylinder is fixedly connected to the upper guide plate.

[0007] Furthermore, the lower electromagnet assembly includes a lower pole fixed to the lower guide plate, a lower pole head fixed to the upper end of the lower pole, and a lower electromagnetic coil fixed to the outer periphery of the lower pole; the lower die punch is fixed to the upper end of the lower pole head; two groups of lower electric cylinders are provided and symmetrically arranged on both sides of the frame; the output end of the lower electric cylinder is fixedly connected to the lower guide plate; the lower guide plate, the lower pole, the lower pole head and the lower die punch are provided with an avoidance channel for the core rod to pass through.

[0008] Furthermore, the frame is provided with a guide column, and the upper guide plate and the lower guide plate are respectively sleeved on the frame and can slide vertically along the guide column.

[0009] Furthermore, the lower end surface of the upper punch is provided with a blind groove adapted to the core rod.

[0010] Furthermore, the depth of the blind groove is between 5 mm and 7 mm.

[0011] Furthermore, when the upper electromagnetic coil and the lower electromagnetic coil are energized, the upper electromagnetic coil and the lower electromagnetic coil are arranged to repel each other.

[0012] Furthermore, the magnetic conductive plate is fixedly mounted on the middle of the frame through fixing blocks on both sides, a mounting groove is provided in the middle of the magnetic conductive plate, and the mold is fixedly mounted in the mounting groove.

[0013] Furthermore, after the upper electromagnetic coil and the lower electromagnetic coil are energized for a set period of time, the upper die punch, the lower die punch and the core rod cooperate to press the NdFeB powder in the annular cavity.

[0014] Furthermore, the feeding device can reciprocate between the powder weighing device and the forming device, and the feeding device fills the NdFeB powder into the annular cavity in batches.

[0015] In summary, the present invention has the following beneficial effects: 1. The present invention arranges the upper electromagnet assembly and the lower electromagnet assembly longitudinally in the frame, which effectively ensures that the magnetization density is more uniform and the magnetization strength is higher; 2. The present invention provides a magnetic conductive plate, which, on the one hand, forms a magnetic circuit during magnetization, reduces magnetic leakage, and improves the magnetic field strength of the mold cavity; on the other hand, it is used to fix the mold and improve the pressing accuracy; 3. The present invention delays the upper die punch and the lower die punch to press the NdFeB powder before the upper electromagnetic coil and the lower electromagnetic coil reach the required magnetization strength, thereby ensuring the magnetization density of the NdFeB powder; 4. The present invention provides a blind groove on the lower end surface of the upper punch. During pressing, the upper punch part extends into the die cavity and the core rod extends into the blind groove, which can not only play a positioning role, but also play a role in guiding magnetic lines of force. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the sealed box body of the present invention.

[0017] Figure 2 It is a structural schematic diagram of the present invention.

[0018] Figure 3 It is a schematic diagram of the internal structure of the mold cavity of the present invention.

[0019] Figure 4 The present invention Figure 3 Enlarged view of point A.

[0020] In the figure: 10, frame; 20, upper electric cylinder; 21, upper guide plate; 22, upper electromagnet assembly; 221, upper electromagnetic coil; 222, upper pole; 223, upper pole head; 23, upper die punch; 231, blind groove; 30, lower electric cylinder; 31, lower guide plate; 311, avoidance channel; 32, lower electromagnet assembly; 321, lower electromagnetic coil; 322, lower pole; 323, lower pole head; 33, lower die punch; 40, core-pulling electric cylinder; 41, core rod; 50, magnetic conductive plate; 51, mold; 52, fixing block; 60, feeding device. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings.

[0022] like Figure 1-Figure 4 As shown, a fully electric radiation ring magnetic field forming press includes a sealed box body, in which a powder weighing device, a feeding device 60 and a forming device are installed. The feeding device 60 can move back and forth between the powder weighing device and the forming device. After the powder weighing device weighs a certain amount of NdFeB powder, the feeding device 60 fills the NdFeB powder into the mold cavity of the mold 51 in batches.

[0023] The forming device includes a frame 10, an upper guide plate 21, an upper electromagnet assembly 22, an upper die punch 23, an upper electric cylinder 20, a mold 51, a lower guide plate 31, a lower electromagnet assembly 32, a lower die punch 33, a lower electric cylinder 30, a core rod 41 and a core-pulling electric cylinder 40. The mold 51 is fixedly connected to the frame 10 through a magnetic plate 50. In the present invention, the mold 51 is a female mold, the upper guide plate 21 is arranged at the upper end of the magnetic plate 50 and can move vertically under the action of the upper electric cylinder 20, the upper electromagnet assembly 22 is fixedly connected to the upper guide plate 21, the upper die punch 23 is fixedly connected to the lower end of the upper electromagnet assembly 22, the lower guide plate 31 is arranged at the lower end of the magnetic plate 50 and can move vertically under the action of the lower electric cylinder 30 The lower electromagnet assembly 32 is fixedly connected to the lower guide plate 31, the lower die punch 33 is fixedly connected to the upper end of the lower electromagnet assembly 32, the upper electromagnet assembly 22 and the lower electromagnet assembly 32 cooperate in magnetization, the core rod 41 is arranged in the middle of the frame 10, and the core rod 41 can be extended and retracted along the cavity of the mold 51 under the action of the core pulling electric cylinder 40. Specifically, the core pulling electric cylinder 40 is fixedly installed at the bottom of the frame 10, and the output end of the core pulling electric cylinder 40 is fixedly connected to the core rod 41, and the lower die punch 33 extends into the cavity of the mold 51. The lower die punch 33, the core rod 41 and the cavity form an annular cavity for filling NdFeB powder, and the quantitative NdFeB powder weighed by the powder weighing device is transferred to the annular cavity through the feeding device 60.

[0024] The frame 10 is provided with guide columns, and the upper guide plate 21 and the lower guide plate 31 are respectively mounted on the frame 10 and can slide vertically along the guide columns. The provision of the guide columns can improve the stability of the upper guide plate 21 and the lower guide plate 31 when moving.

[0025] The upper electromagnet assembly 22 includes an upper pole 222 fixed to the upper guide plate 21, an upper pole head 223 fixed to the lower end of the upper pole 222, and an upper electromagnetic coil 221 fixed to the outer periphery of the upper pole 222. The upper punch 23 is fixed to the lower end of the upper pole head 223. The upper electric cylinder 20 is fixedly installed on the top of the frame 10. The output end of the upper electric cylinder 20 is fixedly connected to the upper guide plate 21. When the upper electric cylinder 20 drives the upper guide plate 21 to move downward along the guide column, the upper electromagnet assembly 22 and the upper punch 23 fixed on the upper guide plate 21 will also move downward synchronously, thereby reducing the distance between the upper electromagnet assembly 22 and the mold 51, and providing a higher magnetization intensity.

[0026] The lower electromagnet assembly 32 includes a lower pole 322 fixed to the lower guide plate 31, a lower pole head 323 fixed to the upper end of the lower pole 322, and a lower electromagnetic coil 321 fixed to the outer periphery of the lower pole 322. The lower die punch 33 is fixed to the upper end of the lower pole head 323. The lower electric cylinder 30 is provided with two groups and symmetrically arranged on both sides of the frame 10, including a left lower electric cylinder 30 and a right lower electric cylinder 30. By setting up two groups of electric cylinders, under the premise of avoiding the core pulling electric cylinder 40, the two groups of electric cylinders can improve the driving force of the lower guide plate 3 In order to ensure the smoothness of the transfer, the output end of the lower electric cylinder 30 is fixedly connected to the lower guide plate 31. The lower guide plate 31, the lower pole 322, the lower pole head 323 and the lower die punch 33 are provided with an avoidance channel 311 for the core rod 41 to pass through. When the lower electric cylinder 30 drives the lower guide plate 31 to move upward along the guide pole, the lower electromagnet assembly 32 and the lower die punch 33 fixed on the lower guide plate 31 will also move upward synchronously, thereby reducing the distance between the lower electromagnet assembly 32 and the mold 51 and providing a higher magnetization strength.

[0027] The lower end surface of the upper punch 23 is provided with a blind groove 231 adapted to the core rod 41. Further, the depth of the blind groove 231 is between 5 mm and 7 mm. The present invention provides the blind groove 231 on the lower end surface of the upper punch 23. During pressing, the upper punch 23 partially extends into the die cavity and the core rod 41 extends into the blind groove 231, which can not only play a positioning role, but also play a role in guiding magnetic lines of force, thereby increasing the magnetic field strength.

[0028] When the upper electromagnetic coil 221 and the lower electromagnetic coil 321 are energized, the upper electromagnetic coil 221 and the lower electromagnetic coil 321 are set to repel each other. For example, when the upper end of the upper electromagnetic coil 221 is the N pole and the lower end is the S pole, the upper end of the lower electromagnetic coil 321 is the S pole and the lower end is the N pole; similarly, when the upper end of the upper electromagnetic coil 221 is the S pole and the lower end is the N pole, the upper end of the lower electromagnetic coil 321 is the N pole and the lower end is the S pole, and the magnetic lines of force of the upper electromagnetic coil 221 and the lower electromagnetic coil 321 form a repelling radiation field in the middle of the mold 51.

[0029] The magnetic conductive plate 50 is fixedly mounted on the middle of the frame 10 through fixing blocks 52 on both sides. A mounting groove is provided in the middle of the magnetic conductive plate 50, and the mold 51 is fixedly mounted in the mounting groove.

[0030] After the upper electromagnetic coil 221 and the lower electromagnetic coil 321 are energized for a set period of time, the upper punch 23, the lower punch 33 and the core rod 41 cooperate to press the NdFeB powder in the annular cavity. The present invention delays the upper punch 23 and the lower punch 33 to press the NdFeB powder before the upper electromagnetic coil 221 and the lower electromagnetic coil 321 reach the required magnetization intensity, thereby ensuring the magnetization density of the NdFeB powder.

[0031] The present invention longitudinally arranges the upper electromagnet assembly 22 and the lower electromagnet assembly 32 in the frame 10, which effectively ensures that the magnetization density is more uniform and the magnetization strength is higher. In addition, the present invention arranges a magnetic conductive plate 50, which, on the one hand, forms a magnetic circuit during magnetization, reduces leakage magnetism, and improves the magnetic field strength of the mold cavity; on the other hand, it is used to fix the mold 51 to improve the pressing accuracy.

[0032] The radiation ring magnetic field pressing and forming method comprises the following steps: S1: Spraying the release agent: The core-pulling electric cylinder 40 drives the core rod 41 to move to a position where the upper end surface of the core rod 41 is 10 mm-20 mm lower than the upper end surface of the mold 51, and the release agent spraying device sprays the release agent into the mold cavity; S2: Filling NdFeB powder: First, the core-pulling electric cylinder 40 drives the core rod 41 to move up to a position where the upper end surface of the core rod 41 is not lower than the upper end surface of the mold 51, then the lower driving member drives the lower die punch 33 to move to a position where the upper end surface of the lower die punch 33 is lower than the upper end surface of the mold 51 by L1mm, and the feeding device 60 fills a certain amount of NdFeB powder into the mold cavity, and then the lower driving member gradually drives the lower die punch 33 to move down by a stroke of L1mm, and after each downward movement of the lower die punch 33 by L1mm, the feeding device 60 gradually fills a certain amount of NdFeB powder into the mold cavity until the NdFeB powder is filled, where 10≤L1≤20; S3: Pre-pressing the upper punch 23: The core rod 41 and the lower punch 33 remain stationary, and the upper driving member drives the upper punch 23 to move downward into the die cavity to pre-press the NdFeB powder. Specifically, in step S3, when the upper punch 23 is pre-pressed, the lower end surface of the upper punch 23 extends into the die cavity by 4 mm to 6 mm; S4: Compression molding: First, the upper punch 23, the lower punch 33 and the core rod 41 remain stationary, and the upper electromagnet assembly 22 fixed to the upper guide plate 21 and the lower electromagnet assembly 32 fixed to the lower guide plate 31 are energized for T1min; then, the upper driving member drives the upper punch 23 to move downward, the core-pulling electric cylinder 40 drives the core rod 41 to move downward synchronously with the upper punch 23, and the lower driving member drives the lower punch 33 to move upward, thereby pressing the NdFeB powder in the mold cavity for T2min until the pressing is completed; S5: Stress release: The lower punch 33 and the core rod 41 remain stationary, and the upper driving member drives the upper punch 23 to move up a distance L2mm and maintain for 1-2 seconds to release the stress of the molded NdFeB magnetic ring, where 0.5≤L2≤2.

[0033] S6: Demolding: The upper driving member drives the upper punch 23 to move upward, the lower driving member drives the lower punch 33 to move upward, and the core-pulling electric cylinder 40 drives the core rod 41 to move upward, thereby demolding the formed NdFeB magnetic ring. In step S6, after the lower punch 33 moves upward until its upper end surface is flush with the upper end surface of the mold 51, the core-pulling electric cylinder 40 drives the core rod 41 to move downward into the mold cavity.

[0034] In step S2, the core-pulling electric cylinder 40 drives the core rod 41 to move up to a position where the upper end surface of the core rod 41 is flush with the upper end surface of the mold 51, so that the feeding device 60 can reciprocate along the mold 51, and each time the feeding device 60 moves, it fills a certain amount of NdFeB powder into the mold cavity.

[0035] Before step S1 or during step S1, a certain amount of NdFeB powder is weighed by a powder weighing device, and after the powder weighing device completes the weighing, the NdFeB powder is transferred to the powder box of the feeding device 60. In steps S3-S4, the feeding device 60 reciprocates along the mold 51 to discharge the NdFeB powder. Specifically, the feeding device 60 moves once and discharges a certain amount of NdFeB powder, that is, the lower electric cylinder 30 drives the lower die punch 33 to move down every Xmm, and the feeding device 60 moves once and pours a certain amount of NdFeB powder. The lower die punch 33 moves down intermittently and cooperates with the batch discharge of NdFeB powder. The NdFeB powder in the powder box of the feeding device 60 after the powder weighing device weighs the powder will be discharged in batches during the above process, which can ensure the uniform density of the NdFeB powder in the mold cavity, thereby ensuring the yield rate of NdFeB magnets.

[0036] The above description is only a preferred embodiment of the present invention, so all equivalent changes or modifications made according to the structure, characteristics and principles described in the scope of the patent application of the present invention are included in the scope of the patent application of the present invention.

Claims

1. A fully electric radiation ring magnetic field forming press, comprising a sealed box, in which a powder weighing device, a feeding device (60) and a forming device are installed, characterized in that: The forming device comprises a frame (10), an upper guide plate (21), an upper electromagnet assembly (22), an upper die punch (23), an upper electric cylinder (20), a mold (51), a lower guide plate (31), a lower electromagnet assembly (32), a lower die punch (33), a lower electric cylinder (30), a core rod (41) and a core-pulling electric cylinder (40); the mold (51) is fixedly connected to the frame (10) via a magnetic conductive plate (50); the upper guide plate (21) is arranged at the upper end of the magnetic conductive plate (50) and can move vertically under the action of the upper electric cylinder (20); the upper electromagnet assembly (22) is fixedly connected to the upper guide plate (21); the upper die punch (23) is fixedly connected to the lower end of the upper electromagnet assembly (22); the lower guide plate (31) is arranged at the magnetic conductive plate (50); The lower end of the mold (50) is movable vertically under the action of the lower electric cylinder (30), the lower electromagnet assembly (32) is fixedly connected to the lower guide plate (31), the lower die punch (33) is fixedly connected to the upper end of the lower electromagnet assembly (32), the upper electromagnet assembly (22) and the lower electromagnet assembly (32) cooperate in magnetization, the core rod (41) is arranged in the middle of the frame (10), the core rod (41) can be extended and retracted along the mold cavity of the mold (51) under the action of the core-pulling electric cylinder (40), the lower die punch (33) extends into the mold cavity of the mold (51), the lower die punch (33), the core rod (41) and the mold cavity form an annular cavity for filling NdFeB powder, and the quantitative NdFeB powder weighed by the powder weighing device is transferred to the annular cavity through the feeding device (60).

2. The all-electric radiation ring magnetic field forming press according to claim 1, characterized in that: The upper electromagnet assembly (22) comprises an upper pole (222) fixed to an upper guide plate (21), an upper pole head (223) fixed to a lower end of the upper pole (222), and an upper electromagnetic coil (221) fixed to an outer periphery of the upper pole (222); an upper die punch (23) is fixed to a lower end of the upper pole head (223); an upper electric cylinder (20) is fixedly mounted on a top of a frame (10); and an output end of the upper electric cylinder (20) is fixedly connected to the upper guide plate (21).

3. The all-electric radiation ring magnetic field forming press according to claim 2, characterized in that: The lower electromagnet assembly (32) comprises a lower pole (322) fixed to a lower guide plate (31), a lower pole head (323) fixed to an upper end of the lower pole (322), and a lower electromagnetic coil (321) fixed to an outer periphery of the lower pole (322); a lower die punch (33) is fixed to an upper end of the lower pole head (323); two groups of lower electric cylinders (30) are provided and are symmetrically arranged on both sides of a frame (10); an output end of the lower electric cylinder (30) is fixedly connected to the lower guide plate (31); and an avoidance channel (311) for a core rod (41) to pass through is provided on the lower guide plate (31), the lower pole (322), the lower pole head (323), and the lower die punch (33).

4. A fully electric radiation ring magnetic field forming press according to any one of claims 1 to 3, characterized in that: The frame (10) is provided with a guide column, and the upper guide plate (21) and the lower guide plate (31) are respectively sleeved on the frame (10) and can slide vertically along the guide column.

5. The all-electric radiation ring magnetic field forming press according to claim 1, characterized in that: The lower end surface of the upper die punch (23) is provided with a blind groove (231) adapted to the core rod (41).

6. The all-electric radiation ring magnetic field forming press according to claim 5, characterized in that: The depth of the blind groove (231) is between 5 mm and 7 mm.

7. The all-electric radiation ring magnetic field forming press according to claim 3, characterized in that: When the upper electromagnetic coil (221) and the lower electromagnetic coil (321) are energized, the upper electromagnetic coil (221) and the lower electromagnetic coil (321) are arranged to repel each other.

8. The all-electric radiation ring magnetic field forming press according to claim 1, characterized in that: The magnetic conductive plate (50) is fixedly mounted on the middle of the frame (10) via fixing blocks (52) on both sides; a mounting groove is provided in the middle of the magnetic conductive plate (50), and the mold (51) is fixedly mounted in the mounting groove.

9. The all-electric radiation ring magnetic field forming press according to claim 3, characterized in that: After the upper electromagnetic coil (221) and the lower electromagnetic coil (321) are energized for a set period of time, the upper die punch (23), the lower die punch (33) and the core rod (41) cooperate to press the NdFeB powder in the annular cavity.

10. The all-electric radiation ring magnetic field forming press according to claim 1, characterized in that: The feeding device (60) can reciprocate between the powder weighing device and the forming device, and the feeding device (60) fills the NdFeB powder into the annular cavity in batches.

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