Automobile filter

Abstract

The invention discloses an automobile filter, and relates to the technical field of filters, and the automobile filter comprises a first capacitor assembly, a second capacitor assembly, and a common-mode and differential-mode integrated inductor. Two ends of the first capacitor assembly are connected with the positive end and the negative end of the input side of the automobile filter, and a first X capacitor and a first Y capacitor are arranged in parallel; two ends of the second capacitor assembly are connected with the positive end and the negative end of the output side of the automobile filter, and a second X capacitor and a second Y capacitor which are connected in parallel are arranged in the second capacitor assembly; the first capacitor assembly and the second capacitor assembly are electrically connected through the common-mode and differential-mode integrated inductor, and the first Y capacitor and the second Y capacitor adopt asymmetric capacitance values; the first X capacitor, the common-differential mode integrated inductor and the second X capacitor are used for suppressing differential mode interference; the first Y capacitor, the common-mode and differential-mode integrated inductor and the second Y capacitor are used for suppressing common-mode interference. According to the invention, effective suppression of differential-mode interference and common-mode interference is realized, the performance of the filter is improved, and the compactness of the structure is also maintained.

Description

Technical Field

[0001] The present application relates to the technical field of filters, and particularly to an automotive filter. Background Art

[0002] With the booming rise of the new energy vehicle industry, the circuit layout density has increased significantly, which not only brings a leap in power density but also exacerbates the noise problem. Against this background, the requirements for EMC (Electromagnetic Magnetic Compatibility) have become increasingly stringent, and it has become one of the key indicators for measuring the performance of automotive electronic devices. To meet this high standard, it is particularly important to equip high-performance filters for the core circuit components of automobiles.

[0003] However, traditional filter design schemes face multiple challenges. On the one hand, within a limited space, the filter circuit often can only adopt a single-stage configuration, which results in the filtering effect being difficult to meet expectations and difficult to meet the growing EMC requirements. On the other hand, whether it is a single-stage or multi-stage filter, the internal Y capacitors usually adopt a symmetric and consistent configuration, which limits the flexibility and adaptability of the filter. In addition, traditional filters often rely solely on common-mode inductors for filtering and lack an effective differential-mode inductor filtering mechanism for high-frequency noise, thus affecting the overall filtering performance.

[0004] To overcome these limitations, the common practice is to improve the filtering performance by means such as increasing the number of components, upgrading the component level, increasing the number of filtering stages, and increasing the number and types of inductors. However, these measures often result in a significant increase in the volume of the filter, which not only increases the installation difficulty but also limits the application potential of the filter in a compact space.

[0005] Therefore, there is a need to develop a compact and high-performance automotive filter at present. Summary of the Invention

[0006] The purpose of the present application is to provide an automotive filter that can improve the filtering performance and maintain the compactness of the structure.

[0007] To achieve the above purpose, the present application provides the following solutions:

[0008] The present application provides an automotive filter, including:

[0009] A first capacitor assembly, a second capacitor assembly, and a common-differential mode integrated inductor;

[0010] Both ends of the first capacitor assembly are respectively connected to the positive and negative terminals of the input side of the automotive filter; the first capacitor assembly includes a first X capacitor and a first Y capacitor connected in parallel;

[0011] Both ends of the second capacitor assembly are respectively connected to the positive and negative terminals on the output side of the automotive filter; the second capacitor assembly includes a second X capacitor and a second Y capacitor connected in parallel;

[0012] The first capacitor assembly and the second capacitor assembly are connected through the common-differential mode integrated inductor; the capacitance values of the first Y capacitor and the second Y capacitor are asymmetric capacitance values;

[0013] The input side of the automotive filter is used to receive the current signal to be filtered; the output side of the automotive filter is used to output the filtered current signal;

[0014] The first X capacitor, the common-differential mode integrated inductor, and the second X capacitor are used to suppress differential mode interference;

[0015] The first Y capacitor, the common-differential mode integrated inductor, and the second Y capacitor are used to suppress common mode interference.

[0016] Optionally, the first Y capacitor specifically includes: a first capacitor and a second capacitor;

[0017] One end of the first capacitor is connected to the positive terminal on the input side of the automotive filter;

[0018] One end of the second capacitor is connected to the negative terminal on the input side of the automotive filter;

[0019] The other end of the first capacitor is connected to the other end of the second capacitor and grounded.

[0020] Optionally, the automotive filter further includes: an injection molded housing, a positive copper busbar, a negative copper busbar, and a grounding copper sheet;

[0021] The injection molded housing is used to encapsulate and protect the first capacitor assembly, the second capacitor assembly, and the common-differential mode integrated inductor;

[0022] The positive terminal on the input side of the automotive filter is connected to one of the positive copper busbars, and the positive terminal on the output side of the automotive filter is connected to the other positive copper busbar;

[0023] The negative terminal on the input side of the automotive filter is connected to one of the negative copper busbars, and the negative terminal on the output side of the automotive filter is connected to the other negative copper busbar;

[0024] The first capacitor is grounded through one of the grounding copper sheets, and the second capacitor is grounded through the other grounding copper sheet;

[0025] The injection molded housing, the positive copper busbar, the negative copper busbar, and the grounding copper sheet are integrally injection molded.

[0026] Optionally, the pin at one end of the first X capacitor is welded to the pin of the positive copper busbar on the input side of the automotive filter through a resistance welding process, and the pin at the other end of the first X capacitor is welded to the pin of the negative copper busbar on the input side of the automotive filter through a resistance welding process.

[0027] Optionally, the pins of the positive copper busbar and the negative copper busbar are both fork-shaped pins.

[0028] Optionally, the positive copper busbar, the negative copper busbar, and the grounding copper sheet are all made of electrolytic copper.

[0029] Optionally, the common differential-mode integrated inductor includes an EE-type ferrite core.

[0030] Optionally, the spatial layouts on both sides of the core of the common differential-mode integrated inductor are the same, and there is an air gap in the middle of the core.

[0031] Optionally, one end of the first capacitor is connected to the positive copper busbar on the input side of the automotive filter through a resistance welding process, and the other end is connected to the grounding copper sheet through a resistance welding process.

[0032] Optionally, the capacitance values of the first X capacitor and the second X capacitor are 1 μF; the capacitance value of the first Y capacitor is 100 nF; the capacitance value of the second Y capacitor is 10 nF.

[0033] According to the specific embodiments provided by the present application, the present application has the following technical effects:

[0034] The present application provides an automotive filter. By designing a structure including a first capacitor component and a second capacitor component, and introducing a common differential-mode integrated inductor, the problem that traditional filters have poor effects in suppressing differential-mode interference and common-mode interference is solved, and efficient filtering of current signals in automotive circuits is achieved; by respectively connecting the first X capacitor and the first Y capacitor, and the second X capacitor and the second Y capacitor in parallel in the first capacitor component and the second capacitor component, and setting the first Y capacitor and the second Y capacitor to have asymmetric capacitance values, the problem that the filter has unbalanced performance when dealing with different frequency interferences is solved, and interference suppression in a wider frequency range is achieved; by connecting the first capacitor component and the second capacitor component with the common differential-mode integrated inductor, not only the structure of the filter is simplified, but also the suppression capabilities of differential-mode interference and common-mode interference are enhanced simultaneously, the problems of large volume, high cost, and low integration degree of the filter are solved, and miniaturization, low cost, and high integration degree of the filter are achieved. Description of the Drawings

[0035] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the accompanying drawings required in the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings.

[0036] Figure 1 A filtering circuit diagram of an automotive filter provided by an embodiment of the present application;

[0037] Figure 2 A top view schematic diagram of the structure of an automotive filter provided by an embodiment of the present application;

[0038] Figure 3 A bottom view schematic diagram of the structure of an automotive filter provided by an embodiment of the present application

[0039] Figure 4 A schematic diagram of copper busbar pins provided by an embodiment of the present application;

[0040] Figure 5 A schematic diagram of the structure of an EE-type ferrite core provided by an embodiment of the present application.

[0041] Reference numerals: Cx1 - First X capacitor, Cx2 - Second X capacitor, Cy1 - First capacitor, Cy2 - Second capacitor, Cy3 - Third capacitor, Cy4 - Fourth capacitor, L1 - Common differential mode integrated inductor, INPUT - Input side of the automotive filter, OUTPUT - Output side of the automotive filter, 1 - Injection molded housing, 2 - Upper half of the common differential mode integrated inductor, 3 - First positive copper busbar, 4 - First negative copper busbar, 5 - Second positive copper busbar, 6 - Second negative copper busbar, 7 - Lower half of the common differential mode integrated inductor, 8 - First grounding copper sheet, 9 - Second grounding copper sheet, 10 - Third grounding copper sheet, 11 - Fourth grounding copper sheet. Detailed implementation manners

[0042] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, rather than all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present application.

[0043] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0044] In an exemplary embodiment, as Figure 1As shown, a filter circuit diagram of an automotive filter is provided. The automotive filter includes:

[0045] A first capacitor component, a second capacitor component, and a common-differential mode integrated inductor L1.

[0046] Both ends of the first capacitor component are respectively connected to the positive and negative terminals of the input side INPUT of the automotive filter; the first capacitor component includes a first X capacitor Cx1 and a first Y capacitor connected in parallel.

[0047] Both ends of the second capacitor component are respectively connected to the positive and negative terminals of the output side OUTPUT of the automotive filter; the second capacitor component includes a second X capacitor Cx2 and a second Y capacitor connected in parallel.

[0048] The first capacitor component and the second capacitor component are connected through the common-differential mode integrated inductor L1; the capacitance values of the first Y capacitor and the second Y capacitor are asymmetric capacitance values.

[0049] The input side INPUT of the automotive filter is used to receive the current signal to be filtered; the output side OUTPUT of the automotive filter is used to output the filtered current signal.

[0050] The first X capacitor Cx1, the common-differential mode integrated inductor L1, and the second X capacitor Cx2 are used to suppress differential mode interference.

[0051] The first Y capacitor, the common-differential mode integrated inductor L1, and the second Y capacitor are used to suppress common mode interference.

[0052] As an optional implementation manner, the first Y capacitor specifically includes: a first capacitor Cy1 and a second capacitor Cy2.

[0053] One end of the first capacitor Cy1 is connected to the positive terminal of the input side INPUT of the automotive filter; one end of the second capacitor Cy2 is connected to the negative terminal of the input side INPUT of the automotive filter; the other end of the first capacitor Cy1 is connected to the other end of the second capacitor Cy2 and grounded.

[0054] The second Y capacitor specifically includes: a third capacitor Cy3 and a fourth capacitor Cy4.

[0055] One end of the third capacitor Cy3 is connected to the positive terminal of the OUTPUT on the output side of the automotive filter; one end of the fourth capacitor Cy4 is connected to the negative terminal of the OUTPUT on the output side of the automotive filter; the other end of the third capacitor Cy3 is connected to the other end of the fourth capacitor Cy4 and grounded. Specifically, the common-mode and differential-mode integrated inductor L1 is installed between the positive and negative lines connected to the first X-capacitor Cx1 and the second X-capacitor Cx2. Through the common-mode and differential-mode integrated inductor L1 formed by the upper half 2 and the lower half 7 of the inductor, common-mode interference and differential-mode interference can be suppressed simultaneously; one end of the first capacitor Cy1 and the third capacitor Cy3 is connected to the positive line and the other end is grounded, and one end of the second capacitor Cy2 and the fourth Cy4 is connected to the negative line and the other end is grounded, which can suppress common-mode interference.

[0056] The Π-type filter circuit composed of the first X-capacitor Cx1, the common-mode and differential-mode integrated inductor L1, and the second X-capacitor Cx2. The filter is installed at the input end of the automotive electric drive controller, which can suppress the interference of the electric drive controller to the outside, and at the same time can suppress the interference of the power grid or system to the electric drive controller.

[0057] As an alternative embodiment, the capacitance values of the first X-capacitor Cx1 and the second X-capacitor Cx1 are 1 μF; the capacitance values of the first capacitor Cy1 and the second capacitor Cy2 are both 100 nF; the capacitance values of the third capacitor Cy3 and the fourth capacitor Cy4 are both 10 nF. The capacitance values of the Y-capacitors are asymmetric, with a 10-fold difference, which can increase the filtering coverage frequency.

[0058] Using the common-mode and differential-mode integrated inductor L1 and asymmetric capacitors for the Y-capacitors, the combination of the common-mode and differential-mode integrated inductor L1 and the asymmetric capacitors expands the filtering frequency band and improves the filter performance.

[0059] In another exemplary embodiment, as Figure 2 and Figure 3 shown, the automotive filter further includes: an injection molding housing 1, two positive copper bars: the first positive copper bar 3 on the input side of the automotive filter, the second positive copper bar 5 on the output side of the automotive filter, two negative copper bars: the first negative copper bar 4 on the input side of the automotive filter, the second negative copper bar 6 on the output side of the automotive filter, and four grounding copper sheets: the first grounding copper sheet 8, the second grounding copper sheet 9, the third grounding copper sheet 10, the fourth grounding copper sheet 11.

[0060] The injection molding housing 1 is used to encapsulate and protect the first capacitor assembly, the second capacitor assembly, and the common-mode and differential-mode integrated inductor L1.

[0061] The positive terminal of the INPUT on the input side of the automotive filter is connected to the first positive copper bar 3, and the positive terminal of the output side of the automotive filter is connected to the second positive copper bar 5.

[0062] The negative terminal of the INPUT side of the automotive filter OUTPUT is connected to the first negative copper bar 4, and the negative terminal of the OUTPUT side of the automotive filter OUTPUT is connected to the second negative copper bar 6.

[0063] The first capacitor Cy1 is grounded through the first grounding copper sheet 8, and the second capacitor Cy2 is grounded through the second grounding copper sheet 9; the third capacitor Cy3 is grounded through the third grounding copper sheet 101, and the fourth capacitor Cy4 is grounded through the fourth grounding copper sheet 11.

[0064] The injection molded housing 1, the two positive copper bars 3 and 5, the two negative copper bars 4 and 6, and the four grounding copper sheets 8, 9, 10 and 11 are integrally injection molded. The material of the injection molded housing 1 is PA66. During injection molding, the two positive copper bars 3 and 5, the two negative copper bars 4 and 6, and the four grounding copper sheets 8, 9, 10 and 11 are placed in the mold, and then glue is injected for integral injection molding. The filter main body has a compact structure and high assembly efficiency.

[0065] As an alternative embodiment, one end of the pin of the first X capacitor Cx1 is welded to the pin of the first positive copper bar 3 on the INPUT side of the automotive filter by resistance welding process, and the other end of the pin of the first X capacitor Cx1 is welded to the pin of the first negative copper bar 4 on the INPUT side of the automotive filter by resistance welding process. The second X capacitor Cx2 is welded to the pins of the second positive copper bar 5 and the second negative copper bar 6 on the OUTPUT side of the automotive filter in the same connection manner, which will not be elaborated here.

[0066] One end of the first capacitor Cy1 is connected to the first positive copper bar 3 on the INPUT side of the automotive filter by resistance welding process, and the other end is connected to the first grounding copper sheet 8 by resistance welding process. The second capacitor Cy2, the third capacitor Cy3 and the fourth capacitor Cy4 are the same as the first capacitor Cy1, and one end is connected to the copper bar and the other end is connected to the grounding copper sheet by resistance welding process, which will not be elaborated here.

[0067] Among them, implementing this embodiment, as Figure 4 shown, the pins of the two positive copper bars 3, 5 and the two negative copper bars 4, 6 are all fork-shaped pins, which are designed specifically for resistance welding.

[0068] In another exemplary embodiment, the two positive copper bars 3 and 5, the two negative copper bars 4 and 6, and the four grounding copper sheets 8, 9, 10 and 11 are all made of red copper, which has good electrical conductivity.

[0069] In another exemplary embodiment, the common-mode differential-mode integrated inductor L1 includes an EE-type ferrite core.

[0070] As an alternative embodiment, as Figure 5As shown, an air gap P1 is added in the middle of the magnetic core to magnify the leakage inductance, which acts as a differential-mode inductance. The spatial layouts on both sides of the magnetic core are the same, acting as a common-mode inductance.

[0071] In the related art, traditional filters generally use common-mode magnetic cores to suppress common-mode interference. However, their design limitation lies in the inability to effectively filter out high-frequency differential-mode interference. To make up for this deficiency, if a differential-mode magnetic core is added, it will inevitably lead to an increase in the number of filter elements and the overall volume of the filter, which not only increases the manufacturing cost but also brings inconvenience to the installation and use of the filter.

[0072] However, an automotive filter of the present application ingeniously integrates two-stage inductance into one stage, not only significantly reducing the volume of the filter but also achieving a compact structure and greatly improving the space utilization rate of the filter. The present application abandons the traditional method of assembling capacitors on a circuit board and instead adopts an advanced process of integrally injecting copper bars and grounding copper sheets with the housing, enabling the capacitors to be directly welded onto the copper bars, which not only simplifies the assembly process but also greatly improves the assembly efficiency and reduces the production cost. The high-performance filter designed in the present application not only successfully solves the deficiency of traditional filters in filtering high-frequency differential-mode interference but also realizes the miniaturization, high efficiency, and low cost of the filter through structural optimization and innovation.

[0073] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0074] Specific examples are used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. An automotive filter, characterized in that: The automotive filter comprises: A first capacitor component, a second capacitor component and a common-differential mode integrated inductor; The two ends of the first capacitor component are respectively connected to the positive terminal and the negative terminal of the input side of the automobile filter; the first capacitor component includes a first X capacitor and a first Y capacitor connected in parallel; The two ends of the second capacitor component are respectively connected to the positive terminal and the negative terminal of the output side of the automobile filter; the second capacitor component includes a second X capacitor and a second Y capacitor connected in parallel; The first capacitor component and the second capacitor component are connected via the common differential mode integrated inductor; the capacitance of the first Y capacitor and the second Y capacitor are asymmetric capacitances; The input side of the automobile filter is used to receive the current signal to be filtered; the output side of the automobile filter is used to output the filtered current signal; The first X capacitor, the common differential mode integrated inductor, and the second X capacitor are used to suppress differential mode interference; The first Y capacitor, the common-differential mode integrated inductor and the second Y capacitor are used to suppress common-mode interference.

2. The automotive filter according to claim 1, characterized in that: The first Y capacitor specifically includes: a first capacitor and a second capacitor; One end of the first capacitor is connected to the positive terminal of the input side of the automobile filter; One end of the second capacitor is connected to the negative terminal of the input side of the automobile filter; The other end of the first capacitor is connected to the other end of the second capacitor and is grounded.

3. The automotive filter according to claim 2, characterized in that: The automobile filter also includes: an injection molded housing, a positive copper bar, a negative copper bar and a grounding copper sheet; The injection molded housing is used to encapsulate and protect the first capacitor component, the second capacitor component and the common-differential mode integrated inductor; The positive terminal on the input side of the automobile filter is connected to one of the positive copper bars, and the positive terminal on the output side of the automobile filter is connected to another of the positive copper bars; The negative terminal of the input side of the automobile filter is connected to one of the negative copper bars, and the negative terminal of the output side of the automobile filter is connected to another of the negative copper bars; The first capacitor is grounded through one of the grounding copper sheets, and the second capacitor is grounded through another of the grounding copper sheets; The injection-molded shell, the positive copper bar, the negative copper bar and the grounding copper sheet are integrally injection-molded.

4. The automotive filter according to claim 3, characterized in that: The pin at one end of the first X capacitor is welded to the pin of the positive copper bar on the input side of the automobile filter by resistance welding, and the pin at the other end of the first X capacitor is welded to the pin of the negative copper bar on the input side of the automobile filter by resistance welding.

5. The automobile filter according to claim 4, characterized in that: The pins of the positive copper busbar and the negative copper busbar are both tree-branch type pins.

6. The automobile filter according to claim 3, characterized in that: The positive copper bar, the negative copper bar and the grounding copper sheet are all made of red copper.

7. The automotive filter according to claim 1, characterized in that: The common-differential mode integrated inductor includes an EE-type ferrite core.

8. The automobile filter according to claim 7, characterized in that: The spatial layouts on both sides of the magnetic core of the common-differential mode integrated inductor are the same, and there is an air gap in the middle of the magnetic core.

9. The automobile filter according to claim 3, characterized in that: One end of the first capacitor is connected to the positive copper bar on the input side of the automobile filter through a resistance welding process, and the other end is connected to the grounding copper sheet through a resistance welding process.

10. The automobile filter according to claim 1, characterized in that: The capacitance of the first X capacitor and the second X capacitor is 1 μF; the capacitance of the first Y capacitor is 100 nF; and the capacitance of the second Y capacitor is 10 nF.

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