High-integration small filter

Abstract

The invention discloses a high-integration small filter in the field of filters. The high-integration small filter comprises a shell, a positive electrode copper bar, a negative electrode copper bar, a filtering assembly, a PCB and an insulating support. The filtering assembly comprises a magnetic core L1, a chip capacitor Cx1-2, a chip capacitor Cy1-4, a ceramic capacitor Cx3 and a resistor Rx1; a containing cavity used for integrating a magnetic core L1 is formed in the shell, and a containing groove used for integrating Cx3 is formed in the upper side of the shell. The insulating bracket is positioned between the anode and cathode copper bars, and the bottom is connected with the shell; the left side of the PCB is connected with the upper side of the shell, and the right side of the PCB is connected with the top of the insulating bracket to form a multi-point supporting structure and is positioned above the insulating bracket; the Cx1, the Cy1-2 and the Rx1 are all located on the lower side of the PCB and electrically connected with the PCB, the Cx2 and the Cy3-4 are both located on the upper side of the PCB and electrically connected with the PCB, the positive electrode copper bar and the negative electrode copper bar penetrate through the L1 and are electrically connected with the Cx3 and the PCB, and the PCB is electrically connected with the grounding elastic piece through the connecting copper bar to form a filter circuit. The high-integration layout is adopted, the size is reduced, the lead and welding technology is simplified, and the production efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of filter technology, and specifically relates to a highly integrated small filter. Background Technology

[0002] With the rapid development of new energy vehicles, their proportion is increasing. In the electronic control system of new energy vehicles, the filter is the bridge connecting the power input terminal and the IGBT. As an indispensable component of the electronic control system, its functions include the following three points: First, the filter is designed with capacitors. When the power supply voltage fluctuates, the capacitors can respond quickly, absorb or replenish electrical energy, and effectively suppress power supply voltage fluctuations. Second, the filter is designed with a combination of inductors and capacitors. Ripple is generated during the conversion and output process of the power supply. The filter circuit composed of inductors and capacitors in the filter can filter out unnecessary ripple and provide a clean DC power supply for the electronic control system. Third, it suppresses electromagnetic interference and ensures the EMC performance requirements of the electronic control system.

[0003] New energy vehicles have a compact interior space layout, especially the limited space for the electronic control system. Traditional filter designs are scattered and bulky, and often use thin-film or ceramic capacitors. The leads of thin-film or ceramic capacitors need to be welded to copper busbars to achieve connection. The large number of capacitor leads leads to complex copper busbar structures and complicated and time-consuming welding processes. In addition, Y capacitors require copper busbars to be designed to connect to the electronic control unit housing, resulting in high design costs.

[0004] Therefore, it is necessary to design a small filter that is suitable for the compact spatial layout of the electric control system of new energy vehicles, has a simple manufacturing process, and is cost-effective. Summary of the Invention

[0005] The purpose of this invention is to provide a highly integrated miniature filter that adopts a highly integrated layout, reduces size, simplifies lead and soldering processes, and improves production efficiency.

[0006] The objective of this invention is achieved as follows: A highly integrated miniature filter, characterized in that it comprises a housing, a copper busbar assembly, a filter assembly, a PCB board, an insulating support, connecting copper busbars, and a grounding spring; the filter assembly includes a magnetic core L1, surface mount capacitors Cx1, Cx2, Cy1, Cy2, Cy3, and Cy4, a ceramic capacitor Cx3, and a resistor Rx1; the housing has a cavity for integrating the magnetic core L1, and an upper groove for integrating the ceramic capacitor Cx3; the copper busbar assembly includes a positive copper busbar and a negative copper busbar; the insulating support is located at... The bottom of the positive and negative copper busbars is fixedly connected to the housing; the left side of the PCB board is fixedly connected to the upper side of the housing, and the right side is fixedly connected to the top of the insulating bracket, forming a multi-point support structure and located above the insulating bracket; the surface mount capacitors Cx1, Cy1, Cy2 and resistor Rx1 are all located on the lower side of the PCB board and electrically connected to it, the surface mount capacitors Cx2, Cy3 and Cy4 are all located on the upper side of the PCB board and electrically connected to it, the copper busbar assembly passes through the magnetic core L1 and is electrically connected to the ceramic capacitor Cx3 and the PCB board respectively, and the PCB board is electrically connected to the grounding spring through the connecting copper busbar to form a filter circuit.

[0007] In use, the power input is first connected to the PCB board via a positive / negative copper busbar assembly. The surface-mount capacitors Cx1, Cy1, and Cy2 on the lower side of the PCB board, and Cx2, Cy3, and Cy4 on the upper side, immediately perform preliminary filtering of the input current. Specifically, Cx1 and Cx2 act as differential-mode capacitors, filtering out differential-mode ripple between power lines; Cy1 and Cy2, and Cy3 and Cy4 act as common-mode capacitors, suppressing common-mode noise from the power lines to the chassis; and resistor Rx1 assists in stabilizing the filtering parameters or discharging static electricity. After preliminary processing by the PCB board... The purified current continues to flow through the copper busbar assembly. At this point, the current passes through the magnetic core L1 (forming a common-mode inductor structure) in the internal cavity of the housing. Utilizing the high inductive reactance of the magnetic core to common-mode current, common-mode electromagnetic interference is further attenuated. Subsequently, the current flows into the ceramic capacitor Cx3 in the internal slot of the housing, where its high-frequency and low-impedance characteristics filter out residual high-frequency noise. Finally, the clean DC power supply, after multi-stage filtering and electromagnetic interference treatment, is discharged through the connection between the PCB board and the grounding spring to the control unit housing, completing the power purification and EMC performance assurance work.

[0008] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The cavity of the magnetic core and the mounting slot of the ceramic capacitor are integrated in the housing at the same time, avoiding the waste of space in the traditional design where the inductor and capacitor are placed in separate spaces, and significantly reducing the overall volume; (2) The space on both sides of the PCB is fully utilized, and the PCB size is compressed to 1 / 2 to 2 / 3 of the traditional single-sided layout, further reducing the area occupied by the filter; (3) The copper busbar assembly passes through the magnetic core as the planar winding of the inductor. The flat structure of the copper busbar makes the magnetic circuit utilization of the magnetic core higher (the magnetic flux density distribution is more uniform). Under the same inductance, the volume is more than 50% smaller than that of the traditional coil, while reducing the parasitic resistance of the inductor (the cross-sectional area of ​​the copper busbar is large and the resistance is small), and improving the Q value (quality factor) and filtering efficiency of the inductor; (4) The PCB onboard housing and insulating support are The "left and right double support" structure is formed, which avoids the deformation of the PCB board due to single-point support. At the same time, the PCB board is fixed above the insulating bracket, reducing the component installation height and achieving a balance between "thinness" and "high stability". (5) The copper busbar assembly, as a rigid conductor, passes through the magnetic core and is directly welded to the ceramic capacitor and PCB board, replacing the traditional "wire + terminal" connection method. The number of connection points is reduced from dozens to four, thereby reducing the probability of contact resistance, poor soldering and loose connection points. (6) The grounding spring is made of elastic metal and is interference-fitted with the control housing. On the one hand, it achieves low impedance grounding by connecting the copper busbar and the PCB board. On the other hand, it fixes the position of the filter in the control housing by elastic deformation, avoiding grounding loosening or component falling off due to vibration, and improving the product's vibration resistance.

[0009] As a further improvement to the technical solution of the present invention, the input port of the filter circuit is connected in parallel with the series branch of Cx1 and Rx1 and Cx2. The two lines of its input circuit are grounded through series connection of Cy1 and Cy2, and series connection of Cy3 and Cy4, respectively. Its main circuit is connected to the output port after series connection of L1, and its output port is connected in parallel with Cx3. Cx1 (located on the lower side of the PCB board) is connected in series with Rx1, and Cx2 (located on the upper side of the PCB board) is connected in parallel. By utilizing the double-sided space of the PCB, the volume of the input circuit is reduced. At the same time, Rx1 is close to Cx1, which reduces the parasitic inductance of the discharge circuit and improves safety and discharge efficiency. Cy1 and Cy2 are on the lower side, and Cy3 and Cy4 are on the upper side, respectively close to the two lines of the input circuit, shortening the connection path to ground, reducing parasitic inductance, and improving the common-mode filtering effect. Cx3 is fixed near the output port through a special mounting slot in the housing, shortening the connection distance with the main circuit, reducing lead inductance, and improving the high-frequency bypass effect.

[0010] As a further improvement to the technical solution of the present invention, both the positive and negative copper busbars include an input section, a main body section, and an output section. The input section includes a first bending portion parallel to the main body section, a second bending portion perpendicular to the positive main body section, and a first conductive pin for electrical connection with the PCB board. The insulating support is located at the overlap of the first bending portion and the main body section and includes a horizontal support plate. A partition and two baffles symmetrically distributed on both sides of the partition are provided on the lower side of the horizontal support plate. The partition has a first limiting groove corresponding to the first bending portion, and the baffle has a second limiting groove corresponding to the main body section. The distance S between the first limiting groove and the baffle is not greater than the thickness of the first bending portion, and the depth H of the second limiting groove is not greater than the thickness of the main body section. An elastic hook is provided at the bottom of the baffle, and the inner wall of the elastic hook is in close contact with the outer wall of the main body section. A plug-in post for connection with the housing is provided on the lower side of the partition, and a riveting post for connection with the PCB board is provided on the upper side of the horizontal support plate. The input section of the copper busbar folds the current path from "horizontal-vertical-horizontal" through bending section one and bending section two, completing the transition from input to main body to output within a limited height. Compared with traditional straight copper busbars, the horizontal space occupied is reduced by 50%. The insulating bracket integrates the positioning and support functions of the copper busbar into one unit through the limiting grooves one and two of the partition and baffle, eliminating the need for additional fixing plates or clamps. Under the limiting effect of the insulating bracket, bending section one and the main body section of the copper busbar always remain in close contact, resulting in a more compact current path, a more concentrated electromagnetic field distribution, and reduced electromagnetic interference to the outside.

[0011] As a further improvement to the technical solution of the present invention, the main body sections of the positive and negative copper busbars are arranged parallel to each other and located within the E-shaped through-hole of the magnetic core L1. The structure of the E-shaped through-hole may allow the copper busbars to be arranged more compactly in a limited space, reducing the overall volume. At the same time, the parallel arrangement of the copper busbars can reduce the electromagnetic coupling between them and reduce external radiation.

[0012] As a further improvement to the technical solution of this invention, the output section includes an L-shaped bend and two conductive pins for electrical connection with the ceramic capacitor Cx3. The L-shaped bend is perpendicular to the main body section and integrally connected thereto. The two conductive pins are located at the top of the L-shaped bend and integrally connected thereto. The integrated design of the L-shaped bend perpendicular to the main body section, through the conversion of spatial direction, not only occupies less radial space within the limited filter, but also matches the mounting slot position of the ceramic capacitor Cx3, making the connection between the copper busbar and Cx3 more compact. By shortening the transmission path and reducing parasitic inductance / resistance, the filtering performance at high frequencies (especially the bypass efficiency for high-frequency noise at the output end) is significantly improved.

[0013] As a further improvement to the technical solution of the present invention, positioning brackets are provided on the outer bottom of the main body section and on the outer top of the L-shaped bend. The positioning brackets include U-shaped clips, and positioning bosses are provided on the left, right, and lower sides of the U-shaped clips. The end faces of the positioning bosses are flush with the injection molding surface of the housing. The copper busbar assembly has grooves corresponding to the U-shaped clips. The positioning bosses on the left and right sides of the U-shaped clips form a lateral (perpendicular to the length direction of the copper busbar) constraint on the copper busbar. The bottom (or top) of the U-shaped clips contacts the lower (or upper) surface of the copper busbar, forming a longitudinal (along the length direction of the copper busbar) constraint. This avoids copper busbar displacement caused by vibration or thermal expansion, ensures the coaxiality of the copper busbar and the E-shaped through hole of the magnetic core, and maintains the stability of the inductance of the inductor.

[0014] As a further improvement to the technical solution of the present invention, the PCB board includes a wave soldering area, which is provided with a plurality of conductive parts for electrical connection with the filter component and a plurality of cutout parts for electrical connection with the copper busbar assembly and connecting copper busbars. The wave soldering area extends outward to form a plurality of riveting areas, which have through holes for fixed connection with the housing or insulating bracket. The filter component is soldered to the PCB board through the conductive parts of the wave soldering area. The position of the cutout parts is precisely aligned with the conductive pins of the copper busbar. During soldering, the solder only fills the contact area between the pins and the PCB board, avoiding the risk of short circuit during copper busbar soldering. The through holes in the same horizontal direction correspond one-to-one with the mounting holes of the housing and the support positions of the insulating bracket. During assembly, only one alignment is required to complete all mechanical fixation.

[0015] As a further improvement to the technical solution of the present invention, the connecting copper busbar includes a snap-fit ​​portion for engaging with the grounding spring. The snap-fit ​​portion has two downwardly bent sides that extend horizontally to form two mounting portions. Each mounting portion has a through hole for fixed connection with the housing, and an integrally connected grounding pin for electrical connection with the PCB board. The snap-fit ​​portion has outwardly extending limiting blocks on both sides corresponding to the grounding spring. The grounding spring directly snaps into the snap-fit ​​portion through elastic deformation, significantly improving assembly efficiency. The double-bent mounting portions enhance the structural strength of the connecting copper busbar, and, in conjunction with the rivet, achieve rigid fixation, ensuring grounding reliability during long-term use. The limiting blocks restrict the position of the grounding spring, preventing a reduction in contact area due to spring fatigue and ensuring stable contact.

[0016] As a further improvement to the technical solution of the present invention, the grounding spring includes a horizontal part arranged parallel to the connecting copper busbar, an arc-shaped part one that bends downward from one end of the horizontal part, a straight fixed part that extends upward from the arc-shaped part, an arc-shaped part two that bends downward from the straight fixed part, an arc-shaped part three that bends upward from the other end of the horizontal part, a curved pressing part that extends upward from the arc-shaped part three, and an arc-shaped part four that bends downward from the pressing part. The fixing part is integrally stamped with an inwardly bent snap-fit ​​spring. The multi-segment arc structure transforms external loads (such as vibration, impact, and thermal expansion stress) into tangential components along the arc path, avoiding stress concentration. The inwardly bent snap-fit ​​spring piece, integrally stamped into the fixing part, forms an "elastic preload" through an interference fit with the connecting copper busbar, ensuring long-term stable contact pressure between the spring piece and the connecting copper busbar. The multi-segment bending design reduces the radial dimension of the spring piece, resulting in an overall volume reduction of 20% to 25% compared to traditional straight spring pieces. The flexible design of the curved pressing part allows it to adapt to non-planar mounting positions of the electronic control housing, avoiding poor contact caused by irregular mounting positions in traditional straight spring pieces.

[0017] As a further improvement to the technical solution of the present invention, the housing includes a bottom plate, a left side plate, a front side plate, a rear side plate and a top plate connected in sequence. The left side plate has two channels through which the L-shaped bending part passes, and two hollow positioning posts through which the main body section passes are provided corresponding to the receiving cavity. The bottom plate has a heat dissipation window at the bottom of the magnetic core L1, and a support part extending outward is provided at the bottom of the insulating bracket. The support part has a mounting hole for connecting with the plug-in post. The top plate has a slot for receiving one side of the PCB board. The slot has a riveting post for connecting with the PCB board and the connecting copper busbar and a protrusion for supporting the snap-fit ​​part. The insulating bracket has guide grooves at the ends of the two hollow positioning posts. The mounting holes mate with the insertion posts of the insulating bracket to form a mechanically locked fixing structure. The surface contact between the support and the insulating bracket allows the weight and vibration load of the insulating bracket to be directly transferred to the base plate, preventing deformation of the insulating bracket due to cantilever installation. The protrusions on the top plate mate with the snap-fit ​​parts of the grounding spring to form an "auxiliary support + limit" structure, enhancing grounding reliability. The side wall of the guide groove mates with the outer wall of the positioning post to restrict the rotational freedom of the positioning post, ensuring the accurate orientation of the main section of the copper busbar and preventing increased magnetic leakage due to rotation. Attached Figure Description

[0018] Figure 1 This is a three-dimensional structural diagram of the present invention.

[0019] Figure 2 This is a three-dimensional structural diagram of the front side of the PCB board in this invention.

[0020] Figure 3 This is a circuit diagram of the filter circuit in this invention.

[0021] Figure 4 This is a three-dimensional structural diagram of the magnetic core in this invention.

[0022] Figure 5 This is a three-dimensional structural diagram of the copper busbar assembly in this invention.

[0023] Figure 6 This is a bottom view of the copper busbar assembly and insulating support in this invention.

[0024] Figure 7 This is a three-dimensional structural diagram of the insulating support in this invention.

[0025] Figure 8 This is a three-dimensional structural diagram of the connecting copper busbar in this invention.

[0026] Figure 9 This is a side view of the grounding spring in this invention.

[0027] Figure 10 This is a three-dimensional structural diagram of the shell in this invention.

[0028] Among them, 1 is the shell, 101 is the receiving cavity, 102 is the receiving groove, 103 is the front side plate, 104 is the rear side plate, 105 is the top plate, 106 is the hollow positioning post, 107 is the heat dissipation window, 108 is the support part, 109 is the mounting hole, 110 is the protrusion, 2 is the 2 PCB board, 201 wave soldering area, 202 cutout section, 203 riveting area, 3 insulating bracket, 301 horizontal support plate, 302 partition plate, 303 baffle plate, 304 limiting groove one, 305 limiting groove two, 306 elastic hook, 307 plug-in post, 308 guide groove, 4 connecting copper busbar, 401 snap-fit ​​part, 402 mounting part, 403 grounding pin, 404 limiting block, 5 grounding spring, 501 horizontal part, 502 arc-shaped part one, 503 fixing part, 504 arc-shaped part two, 505 arc-shaped part three, 506 crimping part, 507 arc-shaped part four, 508 snap-fit ​​spring, 6 positive copper busbar, 7 negative copper busbar, 8 through hole, 9 input section, 901 bending part one, 902 bending part two, 903 conductive pin one, 10 main body section, 11 output section, 1101 L-shaped bend, 1102 conductive pin 2, 12 riveting post, 13 E-shaped through hole, 14 positioning bracket, 1401 U-shaped clamp, 1402 positioning boss, 15 groove. Detailed Implementation

[0029] like Figure 1-2As shown, a highly integrated miniature filter includes a housing 1, a copper busbar assembly, a filter assembly, a PCB board 2, an insulating bracket 3, a connecting copper busbar 4, and a grounding spring 5. The filter assembly includes a magnetic core L1, surface mount capacitors Cx1, Cx2, Cy1, Cy2, Cy3, and Cy4, a ceramic capacitor Cx3, and a resistor Rx1. The housing 1 has a cavity 101 for integrating the magnetic core L1, and a slot 102 for integrating the ceramic capacitor Cx3 on its upper side. The copper busbar assembly includes a positive copper busbar 6 and a negative copper busbar 7. The insulating bracket 3 is located between the input terminals of the positive copper busbar 6 and the negative copper busbar 7, and its bottom is connected to the housing 1. Fixed connection; the left side of PCB board 2 is fixedly connected to the upper side of housing 1, and the right side is fixedly connected to the top of insulating bracket 3, forming a multi-point support structure and suspended above insulating bracket 3, reducing the installation height of components and further miniaturizing them; the surface mount capacitors Cx1, Cy1, Cy2 and resistor Rx1 are all located on the lower side (front) of PCB board 2 and electrically connected to it, the surface mount capacitors Cx2, Cy3 and Cy4 are all located on the upper side (back) of PCB board 2 and electrically connected to it, the copper busbar assembly passes through the winding of the magnetic core L1 which is an inductor and is electrically connected to the ceramic capacitor Cx3 and PCB board 2 respectively, and PCB board 2 is electrically connected to the grounding spring 5 through the connecting copper busbar 4 to form a filter circuit.

[0030] The PCB board 2 includes a wave soldering area 201. The wave soldering area 201 is provided with multiple conductive parts for electrical connection with the filter components and four cutout parts 202 for electrical connection with the copper busbar components and the connecting copper busbar 4. The wave soldering area 201 extends horizontally outward to form two left riveting areas 203 and one right riveting area 203. Each of the three riveting areas 203 has a through hole 8.

[0031] like Figure 3 As shown, the input port of the filter circuit is connected in parallel with the series branch of Cx1 and Rx1 and Cx2. The two lines of its input circuit are grounded via series connection of Cy1 and Cy2, and series connection of Cy3 and Cy4, respectively. Its main circuit is connected to the output port via series connection of L1, and its output port is connected in parallel with Cx3. The parallel branch of the input circuit works in conjunction with the double-sided layout of the PCB to expand the differential-mode filtering bandwidth and enhance common-mode rejection. The copper busbar inductor of the main circuit improves the differential-mode noise attenuation capability through low parasitic parameters and high Q value. The ceramic capacitor of the output circuit, combined with the short lead design, achieves efficient bypassing of high-frequency noise.

[0032] The following is through Figure 4-7The structure of the copper busbar and insulating support 3 is described in detail. Both the positive copper busbar 6 and the negative copper busbar 7 include an input section 9, a main body section 10, and an output section 11. The input section 9 includes a bend 901 parallel to the main body section 10, a bend 902 perpendicular to the plane of the positive main body section 10, and conductive pins 903 for electrical connection with the PCB board 2. The insulating support 3 is located at the overlap of the bend 901 and the main body section 10, and includes a horizontal support plate 301. A partition 302 and two baffles 303 symmetrically distributed on both sides of the partition 302 are provided on the lower side of the horizontal support plate 301. The partition 302 has a limiting groove 304 corresponding to the bend 901, and the baffle 303 has a limiting groove 305 corresponding to the main body section 10. The distance S between the limiting groove 304 and the baffle 303 is equal to the thickness T1 of the bend 901. The depth H of 05 is equal to the thickness T2 of the main body section 10; the bottom of the baffle 303 is provided with an elastic hook 306, the inner wall of the elastic hook 306 is in close contact with the side wall and bottom of the main body section 10, the copper busbar and the insulating support 3 will have relative radial displacement due to the difference in expansion at high temperature, the elastic deformation of the elastic hook 306 can absorb this displacement, avoid hard contact between the copper busbar and the magnetic core or the insulating support 3, and ensure that the main body section 10 and the bending part 901 are always at the same horizontal height; the lower side of the partition 302 is provided with a plug-in post 307 for connecting with the housing 1, guiding the insulating support 3 to quickly align with the installation position of the housing 1, reducing assembly time, and forming a mechanical lock with the plastic material of the housing 1 after insertion into the housing 1, preventing the insulating support 3 from falling off due to vibration or thermal stress; the upper side of the horizontal support plate 301 is provided with a riveting post 12 for connecting with the through hole 8 on the right riveting welding area 203.

[0033] The main body sections 10 of the positive copper busbar 6 and the negative copper busbar 7 are arranged parallel to each other and located within the E-shaped through-hole of the magnetic core L1, with their current directions opposite. According to Ampere's circuital law, the magnetic flux generated by the currents in the two copper busbars is in the same direction at the center of the magnetic core, which enhances the main magnetic flux. On the left and right sides of the magnetic core, their directions are opposite, which can cancel out some of the leakage magnetic flux. This symmetrical arrangement not only enhances the strength of the main magnetic flux but also further reduces the interference of external magnetic fields through the mutual cancellation of leakage magnetic flux.

[0034] The output section 11 includes an L-shaped bend 1101 and a conductive pin 1102 for electrical connection with the ceramic capacitor Cx3. The L-shaped bend 1101 is perpendicular to the plane of the main body section 10 and is integrally connected to it. The conductive pin 1102 is located at the top of the L-shaped bend 1101 and is integrally connected to it. This changes the axial extension of the conductive pin 1102 of the output section 11 into a radial fold, reducing the radial dimension by more than 50% and reducing the overall filter volume by 15% to 20%.

[0035] Positioning brackets 14 are provided on the outer bottom of the main body section 10 and the outer top of the L-shaped bend 1101. The positioning brackets 14 include U-shaped clips 1401. Positioning bosses 1402 are provided on the left, right and bottom sides of the U-shaped clips 1401. The end face of the positioning bosses 1402 is flush with the injection molding surface of the housing 1. The copper busbar assembly has a groove 15 corresponding to the U-shaped clips 1401. The copper busbar forms a two-way constraint of left and right clamping and bottom support through the cooperation of the grooves 15 and the U-shaped clips 1401, directly aligning with the injection and magnetic core plastic reference surface, thereby improving the injection molding accuracy.

[0036] like Figure 8 As shown, the connecting copper busbar 4 includes a snap-fit ​​portion 401 for engaging with the grounding spring piece 5. The snap-fit ​​portion 401 is bent downward on both sides and extends horizontally to form two mounting portions 402. The mounting portions 402 have through holes 8 for fixed connection with the housing 1, and are integrally connected with grounding pins 403 for electrical connection with the PCB board 2. The snap-fit ​​portion 401 is provided with outwardly extending limiting blocks 404 on both sides of the grounding spring piece 5. The grounding spring piece 5 is directly snapped into the snap-fit ​​portion 401 through elastic deformation. The single action is completed in only 3 seconds, which significantly improves the assembly efficiency.

[0037] like Figure 9 As shown, the grounding spring 5 includes a horizontal portion 501 that is parallel and attached to the connecting copper busbar 4, an arc-shaped portion 502 that bends downward from one end of the horizontal portion 501, a straight fixing portion 503 that extends upward from the arc-shaped portion, an arc-shaped portion 504 that bends downward from the straight fixing portion 503, an arc-shaped portion 505 that bends upward from the other end of the horizontal portion 501, a curved pressing portion 506 that extends upward from the arc-shaped portion 505, and an arc-shaped portion 507 that bends downward from the pressing portion 506. The fixing portion 503 is integrally stamped with an inwardly bent snap-fit ​​spring 508. This structure is formed by stamping in one piece. During assembly, the spring only needs to be snapped into the slot of the connecting copper busbar 4. The assembly time of a single piece is reduced from 2 minutes to 30 seconds, which improves production efficiency and reduces production costs.

[0038] like Figure 10As shown, the housing 1 is made by one-piece injection molding and includes a bottom plate, a left side plate, a front side plate 103, a rear side plate 104 and a top plate 105 connected in sequence. The left side plate has two channels through which the L-shaped bending part 1101 passes, and two hollow positioning posts 106 through which the main body section 10 passes, corresponding to the receiving cavity 101. The bottom plate has a heat dissipation window 107 at the bottom of the magnetic core L1 and an outwardly extending support part 108 at the bottom of the insulating bracket 3. The support part 108 has a mounting hole 109 for connecting with the plug-in post 307. The top plate 105 has a slot for receiving one side of the PCB board 2. The slot has a riveting post 12 for fixing to the PCB board 2 and the through hole 8 on the connecting copper busbar 4, as well as two protrusions 110 for supporting the bottom sides of the snap-fit ​​part 401. The insulating bracket 3 has a vertical guide groove 308 at the end of each of the two hollow positioning posts 106.

[0039] During production and assembly, U-shaped clips 1401 are engaged with the main body section 10 and output section 11 of the positive and negative copper busbars 7, respectively. The main body section 10 of the copper busbar is slowly inserted along the axial direction of the magnetic core through hole 8 until the inner boss of the U-shaped clip 1401 on the output section 11 abuts against the side of the magnetic core, and the end of the main body section 10 protrudes from the upper and lower surfaces of the magnetic core. The shell 1 structure, including the main body section 10, output section 11, and magnetic core, is formed by injection molding, and features such as the left side plate channel and hollow positioning post 106 are formed simultaneously. The guide of the insulating bracket 3 is then... Align the groove 308 with the ends of the two hollow positioning posts 106 of the housing 1, and slowly move it downwards in the vertical direction until the insertion post 307 at the bottom of the insulating bracket 3 is completely inserted into the mounting hole 109 on the base plate; gently shake the insulating bracket 3 to verify its stability and confirm that the guide groove 308 is completely in contact with the positioning post, thus completing the fixing of the insulating bracket 3; insert the bent part 901 of the positive and negative copper busbars 7 into the gap between the partition 302 and the baffle 303, and push it along the axial direction of the main body section 10 until it is completely overlapped with the main body section 10; place the PC The PCBA is placed in the slot of the top plate 105 of the housing 1, and the through holes 8 on the PCBA correspond one-to-one with the riveting posts 12 of the housing 1 and the riveting posts 12 of the insulating bracket 3, so that the conductive pin 903 passes through the right-side cutout 202; the connecting copper busbar 4 is placed on the PCBA, and its through holes 8 pass through the riveting posts 12 of the housing 1, and the grounding pin 403 passes through the left-side cutout 202; the hot riveting machine is started, the riveting posts 12 are heated to the plastic deformation temperature, and pressure is applied to the top of the riveting posts 12 through the riveting head, so that it is in the insulating bracket 3 The "mushroom head" shaped riveting structure formed in the hole ensures the connection strength between the PCBA and the housing 1 and the insulating bracket 3; align the pins of the ceramic capacitor Cx3 with the conductive pin 1102 of the copper busbar, align the conductive pin 903 and the grounding pin 403 with the PCBA, and use a laser welding machine to weld them to ensure that the solder joints are smooth and free of cold solder joints, and avoid high temperature damage to the surface mount components on the PCB during the welding process; the grounding spring 5 is bent inward and snapped into the snap-fit ​​part 401 of the copper busbar 4 to achieve quick assembly.

[0040] The advantages of this invention are as follows: the surface mount technology (SMT) is compatible with surface mount components, enabling automated soldering and replacing the tedious process of traditional manual soldering of multiple leads, thus shortening the production cycle and reducing labor costs; the design of the U-shaped clip 1401 engaging the main body section 10 and the output section 11 of the copper busbar significantly improves the assembly accuracy and consistency of the copper busbar and the magnetic core through a dual mechanism of mechanical limiting and injection molding reference; the installation of the insulating bracket 3 and the assembly of the copper busbar input section 9 achieve "one-time alignment and synchronous advancement" through the guide groove 308, reducing the overall assembly cycle from the traditional 15 minutes / piece to 5 minutes / piece, greatly improving production efficiency.

[0041] This invention is not limited to the above embodiments. Based on the technical solutions disclosed in this invention, those skilled in the art can make some substitutions and modifications to some of the technical features without creative effort, and all such substitutions and modifications are within the protection scope of this invention.

Claims

1. A high integration small filter, characterized by, The system includes a housing, a copper busbar assembly, a filter assembly, a PCB board, an insulating support, connecting copper busbars, and a grounding spring. The filter assembly includes a magnetic core L1, surface-mount capacitors Cx1, Cx2, Cy1, Cy2, Cy3, and Cy4, a ceramic capacitor Cx3, and a resistor Rx1. The housing has a cavity for integrating the magnetic core L1 and a slot on its upper side for integrating the ceramic capacitor Cx3. The copper busbar assembly includes a positive copper busbar and a negative copper busbar. The insulating support is located between the positive and negative copper busbars, with its bottom connected to the grounding spring. The housing is fixedly connected; the left side of the PCB board is fixedly connected to the upper side of the housing, and the right side is fixedly connected to the top of the insulating bracket, forming a multi-point support structure and located above the insulating bracket; the surface mount capacitors Cx1, Cy1, Cy2 and resistor Rx1 are all located on the lower side of the PCB board and electrically connected to it, the surface mount capacitors Cx2, Cy3 and Cy4 are all located on the upper side of the PCB board and electrically connected to it, the copper busbar assembly passes through the magnetic core L1 and is electrically connected to the ceramic capacitor Cx3 and the PCB board respectively, and the PCB board is electrically connected to the grounding spring through the connecting copper busbar to form a filter circuit.

2. The highly integrated miniature filter according to claim 1, characterized in that, The input port of the filter circuit is connected in parallel with the series branch of Cx1 and Rx1 and Cx2. The two lines of its input circuit are grounded through series of Cy1 and Cy2 and series of Cy3 and Cy4 respectively. Its main circuit is connected to the output port after being connected in series with L1. Its output port is connected in parallel with Cx3.

3. The highly integrated miniature filter according to claim 1, characterized in that, Both the positive and negative copper busbars include an input section, a main body section, and an output section. The input section includes a first bend parallel to the main body section, a second bend perpendicular to the positive main body section, and a first conductive pin for electrical connection with the PCB board. The insulating support is located at the overlap of the first bend and the main body section and includes a horizontal support plate. A partition and two baffles symmetrically distributed on both sides of the partition are provided on the lower side of the horizontal support plate. The partition has a first limiting groove corresponding to the first bend, and the baffle has a second limiting groove corresponding to the main body section. The distance S between the first limiting groove and the baffle is not greater than the thickness of the first bend, and the depth H of the second limiting groove is not greater than the thickness of the main body section. An elastic hook is provided at the bottom of the baffle, and the inner wall of the elastic hook is in close contact with the outer wall of the main body section. A plug-in post for connection with the housing is provided on the lower side of the partition, and a riveting post for connection with the PCB board is provided on the upper side of the horizontal support plate.

4. A highly integrated miniature filter according to claim 3, characterized in that, The main sections of the positive and negative copper busbars are arranged parallel to each other and located within the E-shaped through hole of the magnetic core L1.

5. A highly integrated miniature filter according to claim 3, characterized in that, The output section includes an L-shaped bend and a second conductive pin for electrical connection with the ceramic capacitor Cx3. The L-shaped bend is perpendicular to the main body section and integrally connected thereto. The second conductive pin is located at the top of the L-shaped bend and integrally connected thereto.

6. A highly integrated miniature filter according to claim 3, characterized in that, Positioning brackets are provided on the outer bottom of the main body section and the outer top of the L-shaped bend. The positioning brackets include U-shaped clips. Positioning bosses are provided on the left, right and lower sides of the U-shaped clips. The end face of the positioning bosses is flush with the injection molding surface of the shell. The copper busbar assembly has a groove corresponding to the U-shaped clip.

7. A highly integrated miniature filter according to claim 1, characterized in that, The PCB board includes a wave soldering area, which has several conductive parts for electrical connection with the filter components and several cutout parts for electrical connection with the copper busbar components and connecting copper busbars. The wave soldering area extends outward to form multiple riveting areas, which have through holes for fixed connection with the housing or insulating bracket.

8. A highly integrated miniature filter according to claim 1, characterized in that, The connecting copper busbar includes a snap-fit ​​part for engaging with the grounding spring. The snap-fit ​​part is bent downward on both sides and extends horizontally to form two mounting parts. The mounting parts have through holes for fixed connection with the housing. Grounding pins for electrical connection with the PCB board are integrally connected. The snap-fit ​​part has outwardly extending limiting blocks on both sides corresponding to the grounding spring.

9. A highly integrated miniature filter according to claim 1, characterized in that, The grounding spring includes a horizontal part parallel to the connecting copper busbar, an arc-shaped part one that bends downward from one end of the horizontal part, a straight fixed part that extends upward from the arc-shaped part, an arc-shaped part two that bends downward from the straight fixed part, an arc-shaped part three that bends upward from the other end of the horizontal part, a curved crimping part that extends upward from the arc-shaped part three, and an arc-shaped part four that bends downward from the crimping part. The fixed part is integrally stamped with an inwardly bent snap-fit ​​spring.

10. A highly integrated miniature filter according to claim 5, characterized in that, The housing includes a bottom plate, a left side plate, a front side plate, a rear side plate, and a top plate connected in sequence. The left side plate has two channels inside for L-shaped bends to pass through, and two hollow positioning posts for the main body sections to pass through the corresponding cavity. The bottom plate has a heat dissipation window at the bottom of the magnetic core L1, and an outwardly extending support part at the bottom of the insulating bracket. The support part has mounting holes for connecting with the plug-in posts. The top plate has a slot for accommodating one side of the PCB board. The slot has a riveting post for connecting with the PCB board and the connecting copper busbar, and a protrusion for supporting the snap-fit ​​part. The insulating bracket has guide grooves at the ends of the two hollow positioning posts.

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