A method for grinding and processing magnetic cores for switching power supply transformers

Abstract

This invention provides a method for grinding magnetic cores for switching power supply transformers, applicable to the field of magnetic core grinding. This application utilizes the cooperation between a jig and an inner housing. During use, two sets of traction wheels drive the jig to rotate within a transmission tube. When the jig enters the curved tube of the inner housing, the inner housing reciprocates at high frequency in the horizontal direction under the vibration of a high-frequency vibration motor. This causes the grinding medium within the inner housing to continuously pass through the guide holes, scouring the magnetic core and thus completing the high-speed grinding operation. Grinding is performed in a cyclical manner, resulting in high grinding efficiency. This grinding method effectively addresses burrs and rough edges generated during conventional grinding. Utilizing a fluid-like scouring grinding method with the grinding medium allows for smooth passage through the corners and dead zones of the magnetic core, achieving high grinding precision and effectively improving the surface finish of the magnetic core, thus enhancing grinding quality. This method has market potential and is suitable for widespread application.

Description

Technical Field

[0001] This application relates to the field of magnetic core polishing, and in particular to a method for polishing magnetic cores for switching power supply transformers. Background Technology

[0002] A switching power supply transformer is a soft magnetic electromagnetic component that functions as a power transmitter, voltage converter, and insulation barrier. It is widely used in power supply technology and power electronics technology.

[0003] Due to its small size, high inductive reactance, convenient winding, high inductance per unit space, and balanced magnetic shielding and heat dissipation, POT-type magnetic cores are widely used in carrier filters, high-sensitivity sensors, high-efficiency sensors, power conversion transformers, etc.

[0004] Due to the structural characteristics of traditional POT-type magnetic cores, conventional grinding methods only grind the top and bottom flat surfaces, which easily produces burrs on the grinding edges and cannot handle the internal dead corners. Manual grinding is costly and seriously affects the factory quality of POT-type magnetic cores. To address these issues, we propose a grinding processing method for magnetic cores used in switching power supply transformers. Summary of the Invention

[0005] The purpose of this application is to design a highly automated grinding method to solve the technical problem that traditional magnetic core dead corners cannot be ground. Compared with the prior art, it provides a grinding method for magnetic cores of switching power supply transformers. The method involves fine grinding equipment and a traction mechanism for circulating and transporting magnetic cores in the fine grinding equipment. The fine grinding equipment includes a frame, an outer box fixed at the bottom of the frame, an inner box horizontally slidably connected inside the outer box, shock-absorbing springs clamped between the two sides of the inner box and the outer box, a high-frequency vibration motor fixed on the inner box, grinding media filled inside the inner box, and a transmission pipe between the inner box and the outer box. The transmission pipe includes a curved pipe body set inside the inner box and a straight pipe body set at the top of the frame. The curved pipe body is provided with mesh holes to facilitate the flow of grinding media.

[0006] The traction mechanism consists of multiple jigs connected end to end. Each jig includes a front cover and a rear cover that are nested together. The front cover and the rear cover are slidably connected along the axis.

[0007] The method specifically includes the following steps:

[0008] S1. The placement frame containing the finished magnetic core is removed by machine and placed in the inner cavity of the refrigeration unit. Liquid nitrogen is used to smoothly and stably cool the magnetic core.

[0009] S2. The finished magnetic core is rough ground using a surface grinder to flatten the end and bottom surfaces of the magnetic core, achieving the required flatness and electromagnetic performance of the finished magnetic core.

[0010] S3. After the magnetic core is coarsely ground in step S2, it is cleaned and then fed into the jig of the traction mechanism of the fine grinding equipment via a conveyor belt. Driven by the jigs connected end to end, the magnetic core moves in a step-by-step manner in the same fixed direction in the transmission tube. When the jig carrying the magnetic core enters the curved tube of the inner box, the inner box moves back and forth in a high frequency in the horizontal direction due to the vibration of the high-frequency vibration motor. This causes the grinding media in the inner box to continuously pass through the jig and wash the magnetic core, thereby completing the high-speed grinding operation and removing the burrs and dead corners generated during the coarse grinding process.

[0011] S4. The finely ground magnetic core is cleaned and dried a second time to complete the grinding operation.

[0012] Furthermore, the polishing media, by mass ratio, includes 50-60 parts silicon carbide particles, 20-30 parts boron carbide synthetic diamond particles, 10-20 parts silicone oil, and 30-40 parts water.

[0013] Furthermore, a sliding plate corresponding to the outer casing is fixed on the straight pipe body, and the traction mechanism is in the form of a chain that circulates in a fixed direction inside the transmission pipe.

[0014] Furthermore, the first and last covers are provided with through holes that match the cross-sectional profile of the magnetic core. Ball heads are fixed on the opposite sides of the first and last covers, and adjacent ball heads are connected by universal ball sleeves.

[0015] Furthermore, the ends of the first and last covers that are far apart are both streamlined. The first and last covers are provided with several through guide holes along the axial direction. A baffle ring is fixed on one side of the first cover, and the outer diameter of the baffle ring is equal to the inner diameter of the transmission pipe.

[0016] Furthermore, two sets of traction wheels are symmetrically fixed at both ends of the top of the frame. The traction wheels are driven by stepper motors, and a notch corresponding to the traction wheels is provided on one side of the straight tube body.

[0017] Furthermore, the magnetic core is a POT-type magnetic core structure, with symmetrical slots on both sides of the magnetic core. The inner wall of the tail cover has elastic protrusions corresponding to the slots, and a top post is fixed to one end of the inner wall of the tail cover.

[0018] Furthermore, a robotic arm is fixed to the top of the frame. The straight tube body has an opening at the bottom of the robotic arm. The robotic arm is used to grip the magnetic core from the conveyor belt and place it in the fixture at the opening. A material ejection frame is provided at the bottom of the opening.

[0019] Furthermore, two sets of symmetrically arranged limiting guide rails are fixed inside the straight tube, and the outer wall of the first cover is provided with limiting grooves corresponding to the limiting guide rails.

[0020] Furthermore, both the front and rear covers are magnetic structures, and there is a close magnetic attraction between them.

[0021] Compared to existing technologies, the advantages of this application are:

[0022] (1) The grinding process provided by the present invention can effectively deal with the burrs and rough edges generated in conventional grinding compared with the traditional magnetic core grinding process. The grinding medium is used for fluid flushing grinding. On the one hand, the grinding force is gentle and will not cause the magnetic core to break during the grinding process. On the other hand, the grinding medium can pass smoothly through the corners and dead corners of the magnetic core. The grinding precision is high, which can effectively improve the surface smoothness of the magnetic core and improve the grinding quality. It has market prospects and is suitable for promotion and application.

[0023] (2) The present invention utilizes the mutual cooperation between the fixture with the first cover and the last cover and the inner box with the grinding medium and the high-frequency vibration motor. In actual use, the two sets of traction wheels rotate in the same direction, driving the fixture connected end to end to move in a step-by-step manner in the transmission tube. When the fixture loaded with the magnetic core enters the curved tube of the inner box, the inner box moves back and forth in the horizontal direction at high frequency under the vibration of the high-frequency vibration motor, driving the grinding medium in the inner box to continuously pass through the guide hole and wash the magnetic core, thereby completing the high-speed grinding operation. Grinding is carried out in a cyclic manner, and the grinding efficiency is high.

[0024] (3) Through the design of the retaining ring, when the grinding medium vibrates and scours in the curved tube, the grinding medium will preferentially flow through the guide hole due to the obstruction of the retaining ring, so that the grinding medium can act efficiently on the surface of the magnetic core. At the same time, the design of the retaining ring can effectively block the grinding medium when the straight tube part of the fixture moves up or down, preventing the rapid loss of the grinding medium and reducing the loss of the grinding medium.

[0025] (4) By cooperating with the limiting guide rail and the limiting groove, the fixture is moved to the opening of the straight tube body under the traction force of the traction wheel, that is, the loading and unloading station of the robot. By using the limitation of the limiting guide rail, the through hole on the fixture is always kept vertically upward, which makes it easy for the robot to hold the magnetic core to be ground, place it in the through hole and press down, so that the magnetic core to be ground squeezes the already ground magnetic core in the fixture. On the one hand, the slot of the magnetic core to be ground and the elastic protrusion are aligned and fixed, and on the other hand, the already ground magnetic core is squeezed out from the through hole and enters the unloading frame to complete the loading and unloading action, thereby improving the degree of automation, improving the grinding efficiency and reducing labor costs.

[0026] (5) Through the design of the magnetic structure of the first and tail covers, when the fixture moves to the straight part of the transmission tube under the traction of the traction wheel, the traction force of the traction wheel is small at this point. The first and tail covers will approach each other by the magnetic attraction between them, so that the through holes on the first and tail covers will overlap, which facilitates the loading and unloading of the robot. When the fixture moves into the curved tube, the traction force is large due to the friction of the grinding medium. At this time, the traction force forces the first and tail covers to move away from each other, so that the through holes on the first and tail covers will be misaligned, reducing the actual passing area of ​​the through holes. This effectively prevents the magnetic core from loosening and falling off due to the impact of the grinding medium, and effectively ensures the clamping stability of the fixture. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the method flow of this application;

[0028] Figure 2 This is a schematic diagram of the structure of the rack and its components proposed in this application;

[0029] Figure 3 for Figure 2 Enlarged structural diagram of section A in the middle;

[0030] Figure 4 This is a structural schematic diagram of the inner casing and its components proposed in this application;

[0031] Figure 5 This is a schematic diagram of the internal structure of the inner box proposed in this application;

[0032] Figure 6 This is a schematic diagram of the internal structure of the transmission tube proposed in this application;

[0033] Figure 7 This is a schematic diagram of the fixture proposed in this application;

[0034] Figure 8 This is a schematic diagram of the exploded structure of the jig proposed in this application;

[0035] Figure 9 This is a schematic diagram showing the loading and unloading status of the fixture proposed in this application;

[0036] Figure 10 This is a schematic diagram of the jig's operating path as proposed in this application;

[0037] Figure 11 This is a schematic diagram of the grinding media's path in the fixture as proposed in this application.

[0038] Explanation of the labels in the diagram:

[0039] Frame 1, Outer housing 2, Inner housing 21, Shock-absorbing spring 22, High-frequency vibration motor 23, Transmission pipe 3, Straight pipe 31, Curved pipe 32, Slide plate 33, Robotic arm 4, Unloading frame 5, Limiting guide rail 6, Fixture 7, First cover 71, Retaining ring 711, Tail cover 72, Elastic protrusion 721, Top column 722, Ball head 73, Universal ball sleeve 74, Through hole 75, Limiting groove 76, Guide hole 77, Traction wheel 8, Magnetic core 9, Slot 91. Detailed Implementation

[0040] The embodiments will be described clearly and completely with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments in this application without creative effort are within the scope of protection of this application.

[0041] Example 1:

[0042] This invention provides a method for grinding and machining magnetic cores for switching power supply transformers. Please refer to [link / reference]. Figure 1-11 The method relates to a fine grinding equipment and a traction mechanism for circulating and transporting a magnetic core 9 within the fine grinding equipment. The fine grinding equipment includes a frame 1, an outer box 2 fixed at the bottom of the frame 1, an inner box 21 horizontally slidably connected inside the outer box 2, shock-absorbing springs 22 clamped between the inner box 21 and the outer box 2 on both sides, a high-frequency vibration motor 23 fixed on the inner box 21, a grinding medium filled inside the inner box 21, and a transmission pipe 3 between the inner box 21 and the outer box 2. The transmission pipe 3 includes a curved pipe 32 disposed inside the inner box 21 and a straight pipe 31 disposed at the top of the frame 1. The curved pipe 32 is provided with mesh holes to facilitate the flow of the grinding medium.

[0043] The traction mechanism consists of multiple jigs 7 connected end to end. The jig 7 includes a front cover 71 and a rear cover 72 that are sleeved on each other. The front cover 71 and the rear cover 72 are slidably connected along the axis.

[0044] The method specifically includes the following steps:

[0045] S1. The placement frame containing the finished magnetic core 9 is removed by the machine and placed in the inner cavity of the refrigeration device. Liquid nitrogen is used to smoothly and stably cool the magnetic core 9.

[0046] S2. The magnetic core 9 is rough ground using a surface grinder to flatten the end face and bottom face of the magnetic core 9, so as to meet the requirements for flatness and electromagnetic performance of the end face and bottom face of the magnetic core 9.

[0047] S3. After the rough grinding of the magnetic core 9 in step S2 is completed, it is cleaned and then fed into the jig 7 of the traction mechanism of the fine grinding equipment by a conveyor belt. Driven by the jig 7 connected end to end, the magnetic core 9 moves in a stepping motion in the same fixed direction in the transmission tube 3. When the jig 7 carrying the magnetic core 9 enters the curved tube 32 of the inner box 21, the inner box 21 moves back and forth in a high frequency in the horizontal direction due to the vibration of the high frequency vibration motor 23. This causes the grinding media in the inner box 21 to continuously pass through the jig 7 and wash the magnetic core 9, thereby completing the high-speed grinding operation. This removes the burrs generated during the rough grinding process and the burrs in the dead corners. The grinding media includes 50-60 parts of silicon carbide particles, 20-30 parts of boron carbide artificial diamond particles, 10-20 parts of silicone oil, and 30-40 parts of water by mass ratio.

[0048] S4. The finely ground magnetic core 9 is cleaned and dried a second time to complete the grinding operation.

[0049] The polishing method provided by this invention, compared with the traditional magnetic core polishing process, can effectively deal with the burrs and rough edges generated in conventional polishing. It uses a fluid-like scouring polishing method with polishing media, which on the one hand, the polishing force is gentle and will not cause the magnetic core to break during the polishing process. On the other hand, the polishing media can smoothly pass through the edges and corners of the magnetic core, resulting in high polishing precision. It can effectively improve the surface smoothness of the magnetic core and improve the polishing quality, which has market prospects and is suitable for promotion and application.

[0050] Example 2:

[0051] This invention provides a method for grinding and machining magnetic cores for switching power supply transformers. Please refer to [link / reference]. Figure 1-11 Components that are the same as or corresponding to those in Embodiment 1 are referred to by the same reference numerals as those in Embodiment 1. For the sake of simplicity, only the differences from Embodiment 1 will be described below:

[0052] A sliding plate 33 corresponding to the outer casing 2 is fixed on the straight tube body 31. The traction mechanism is in the form of a chain and runs in a fixed direction in the transmission tube 3. The curved tube body 32 is provided with mesh holes to facilitate the flow of grinding media. The first cover body 71 and the tail cover body 72 are provided with through holes 75. The through holes 75 match the cross-sectional profile of the magnetic core 9. Ball heads 73 are fixed on the opposite sides of the first cover body 71 and the tail cover body 72. Adjacent ball heads 73 are connected by universal ball sleeves 74.

[0053] This invention utilizes the interaction between a fixture 7 with a head cover 71 and a tail cover 72 and an inner box 21 containing polishing media and a high-frequency vibration motor 23. In actual use, the two sets of traction wheels 8 rotate in the same direction, driving the fixture 7 connected end to end to move in a step-by-step manner in the transmission pipe 3. When the fixture 7 loaded with the magnetic core 9 enters the curved tube 32 of the inner box 21, the inner box 21 moves back and forth in a high-frequency direction under the vibration of the high-frequency vibration motor 23, causing the polishing media in the inner box 21 to continuously pass through the guide hole 77 and wash the magnetic core 9, thereby completing the high-speed polishing operation. Polishing is carried out in a cyclic manner, resulting in high polishing efficiency.

[0054] It should be noted that the ends of the first cover 71 and the tail cover 72 that are far apart are both streamlined. The first cover 71 and the tail cover 72 are provided with several through guide holes 77 along the axial direction. A retaining ring 711 is fixed on one side of the first cover 71. The outer diameter of the retaining ring 711 is equal to the inner diameter of the transmission pipe 3. Two sets of traction wheels 8 are symmetrically fixed at both ends of the top of the frame 1. The traction wheels 8 are driven by stepper motors. A notch corresponding to the traction wheel 8 is provided on one side of the straight pipe 31.

[0055] Please see Figure 11 Through the design of the retaining ring 711, when the grinding media vibrates and scours inside the curved tube 32, the grinding media preferentially flows through the guide hole 77 due to the obstruction of the retaining ring 711, thereby enabling the grinding media to act efficiently on the surface of the magnetic core 9. At the same time, the design of the retaining ring 711 can effectively block the grinding media when the straight tube 31 of the fixture 7 moves up or down, preventing the rapid loss of the grinding media and reducing the loss of the grinding media.

[0056] Among them, the magnetic core 9 is a POT type magnetic core structure. The magnetic core 9 has symmetrical slots 91 on both sides. The inner wall of the tail cover 72 has elastic protrusions 721 corresponding to the slots 91. One end of the inner wall of the tail cover 72 is also fixed with a top column 722. The top of the frame 1 is also fixed with a robot arm 4. The straight tube 31 has an opening at the bottom of the robot arm 4. The robot arm 4 is used to clamp the magnetic core 9 from the conveyor belt and place it in the fixture 7 at the opening. The bottom of the opening is provided with a material ejection frame 5. Two sets of symmetrically arranged limiting guide rails 6 are fixed inside the straight tube 31. The outer wall of the head cover 71 is provided with a limiting groove 76 corresponding to the limiting guide rails 6.

[0057] By cooperating with the limiting guide rail 6 and the limiting groove 76, the fixture 7 is moved to the opening of the straight tube 31 under the traction force of the traction wheel 8, which is the loading and unloading station of the robot arm 4. By using the limitation of the limiting guide rail 6, the through hole 75 on the fixture 7 is always kept vertically upward, which makes it easy for the robot arm 4 to clamp the magnetic core 9 to be ground, place it in the through hole 75 and press it down, so that the magnetic core 9 to be ground squeezes the already ground magnetic core 9 in the fixture 7. On the one hand, the slot 91 of the magnetic core 9 to be ground aligns and is fixed with the elastic protrusion 721. On the other hand, the already ground magnetic core 9 is squeezed out from the through hole 75 and enters the unloading frame 5 to complete the loading and unloading action. This improves the degree of automation, improves the grinding efficiency and reduces labor costs.

[0058] Both the first cover 71 and the tail cover 72 are magnetic structures, and there is a close magnetic attraction between the first cover 71 and the tail cover 72.

[0059] Through the design of the magnetic structure of the first cover 71 and the tail cover 72, when the fixture 7 moves to the straight part of the transmission tube 3 under the traction of the traction wheel 8, the traction force of the traction wheel 8 is small at this point. The first cover 71 and the tail cover 72 will move closer together by the magnetic attraction between them, so that the through holes 75 on the first cover 71 and the tail cover 72 will overlap, which facilitates the loading and unloading of the robot arm 4. When the fixture 7 moves into the curved tube 32, the traction force is large due to the friction of the grinding medium. At this time, the traction force forces the first cover 71 and the tail cover 72 to move away from each other, so that the through holes 75 on the first cover 71 and the tail cover 72 will be misaligned, reducing the actual passing area of ​​the through holes 75. This effectively prevents the magnetic core 9 from loosening and falling off due to the impact of the grinding medium, and effectively ensures the clamping stability of the fixture 7.

[0060] The above description is merely the best implementation method adopted in light of current practical needs, but the scope of protection of this application is not limited thereto.

Claims

1. A method for grinding and processing magnetic cores for switching power supply transformers, characterized in that, The method relates to a fine grinding device and a traction mechanism for circulating a magnetic core (9) within the fine grinding device. The fine grinding device includes a frame (1), an outer box (2) fixed at the bottom of the frame (1), an inner box (21) horizontally slidably connected inside the outer box (2), shock-absorbing springs (22) clamped between the inner box (21) and the outer box (2) on both sides, a high-frequency vibration motor (23) fixed on the inner box (21), a grinding medium filled inside the inner box (21), a transmission pipe (3) between the inner box (21) and the outer box (2), the transmission pipe (3) including a curved tube (32) disposed inside the inner box (21) and a straight tube (31) disposed at the top of the frame (1), and a mesh for facilitating the flow of the grinding medium on the curved tube (32). The traction mechanism consists of multiple jigs (7) connected end to end. Each jig (7) includes a front cover (71) and a rear cover (72) that are sleeved on each other. The front cover (71) and the rear cover (72) are slidably connected along the axis. The method specifically includes the following steps: S1. The placement frame containing the finished magnetic core (9) is taken out by the machine and placed in the inner cavity of the refrigeration device. Liquid nitrogen is used to smoothly and stably cool the magnetic core (9). S2. The magnetic core (9) is rough ground by a surface grinder to make the end face and bottom face of the magnetic core (9) flat, so as to meet the flatness and electromagnetic performance requirements of the end face and bottom face of the magnetic core (9). S3. The magnetic core (9) after rough grinding in step S2 is cleaned and then fed into the jig (7) of the traction mechanism of the fine grinding equipment by a conveyor belt. Driven by the jig (7) connected end to end, the magnetic core (9) moves in the same fixed direction in the transmission tube (3). When the jig (7) loaded with the magnetic core (9) enters the curved tube (32) of the inner box (21), the inner box (21) moves back and forth in the horizontal direction at high frequency under the vibration of the high frequency vibration motor (23), which drives the grinding medium in the inner box (21) to continuously pass through the jig (7) and wash the magnetic core (9), thereby completing the high-speed grinding operation and removing the burrs and dead corners generated during the rough grinding process. S4. The finely ground magnetic core (9) is cleaned and dried a second time to complete the grinding operation.

2. The method for grinding and processing magnetic cores for switching power supply transformers according to claim 1, characterized in that, The polishing medium comprises, by mass ratio, 50-60 parts silicon carbide particles, 20-30 parts boron carbide synthetic diamond particles, 10-20 parts silicone oil, and 30-40 parts water.

3. The method for grinding and processing magnetic cores for switching power supply transformers according to claim 1, characterized in that, The straight tube (31) is fixed with a sliding plate (33) corresponding to the outer box (2), and the traction mechanism is in the form of a chain and runs in a fixed direction in the transmission tube (3).

4. The method for grinding and processing magnetic cores for switching power supply transformers according to claim 3, characterized in that, The first cover (71) and the tail cover (72) are provided with through holes (75), which match the cross-sectional profile of the magnetic core (9). Ball heads (73) are fixed on the opposite sides of the first cover (71) and the tail cover (72), and adjacent ball heads (73) are connected by universal ball sleeves (74).

5. The method for grinding and processing magnetic cores for switching power supply transformers according to claim 4, characterized in that, The ends of the first cover (71) and the tail cover (72) that are far apart are both streamlined. The first cover (71) and the tail cover (72) are provided with several through guide holes (77) along the axial direction. A retaining ring (711) is fixed on one side of the first cover (71), and the outer diameter of the retaining ring (711) is equal to the inner diameter of the transmission pipe (3).

6. The method for grinding and processing magnetic cores for switching power supply transformers according to claim 5, characterized in that, Two sets of traction wheels (8) are symmetrically fixed at both ends of the top of the frame (1). The traction wheels (8) are driven by a stepper motor. A notch corresponding to the traction wheel (8) is provided on one side of the straight tube body (31).

7. The method for grinding and processing magnetic cores for switching power supply transformers according to claim 4, characterized in that, The magnetic core (9) is a POT type magnetic core structure. The magnetic core (9) has symmetrical slots (91) on both sides. The inner wall of the tail cover (72) is provided with elastic protrusions (721) corresponding to the slots (91). One end of the inner wall of the tail cover (72) is also fixed with a top post (722).

8. The method for grinding and processing magnetic cores for switching power supply transformers according to claim 4, characterized in that, The top of the frame (1) is also fixed with a robot arm (4), and the straight tube (31) has an opening at the bottom of the robot arm (4). The robot arm (4) is used to clamp the magnetic core (9) from the conveyor belt and place it in the fixture (7) at the opening. A material ejection frame (5) is provided at the bottom of the opening.

9. A method for grinding and processing magnetic cores for switching power supply transformers according to claim 8, characterized in that, The straight tube (31) is fixed with two sets of symmetrically arranged limiting guide rails (6), and the outer wall of the first cover (71) is provided with a limiting groove (76) corresponding to the limiting guide rails (6).

10. A method for grinding and processing magnetic cores for switching power supply transformers according to claim 4, characterized in that, Both the first cover (71) and the tail cover (72) are magnetic structures, and the first cover (71) and the tail cover (72) have a close magnetic attraction.

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