π-type tubular filter

Abstract

The present invention is applicable to the technical field of military filtering equipment, and specifically relates to a π-type tubular filter, which includes a tube shell, an inductor, a capacitor assembly, an input terminal, and an output terminal; the inductor is arranged inside the tube shell; the capacitor assembly is arranged inside the tube shell and includes a circuit board and chip capacitors electrically connected to the circuit board, and the capacitor assembly is respectively arranged on both sides of the inductor; the input terminal and the output terminal are respectively arranged at both ends of the tube shell, and an electrical connection is formed between the input terminal, the capacitor assembly, the inductor, and the output terminal to form a π-type filter circuit. A first colloid is integrally potted inside the tube shell, and the insertion parts of the input terminal and the output terminal are potted in a second colloid. The second colloid is used to seal both ends of the tube shell, and the insertion parts of the input terminal and the output terminal are limit structures that prevent pulling and rotation. The aim is to solve the technical problems in the prior art that the terminals are prone to rotation and falling off, and the overall vibration resistance and impact resistance of the filter are relatively weak.

Description

Technical Field

[0001] The present invention relates to the technical field of military filtering equipment, and more specifically, to a π-type tubular filter. Background Art

[0002] A filter is a filtering circuit composed of capacitors, inductors, and resistors. The filter can effectively filter out specific frequency points in the power line or frequencies outside that frequency point, obtaining a power signal with a specific frequency or eliminating the power signal after a specific frequency.

[0003] The π-type filter is a commonly used filter. The traditional π-type tubular filter faces problems such as terminal rotation and terminal pulling out, and cannot be integrally potted inside. The terminals are prone to looseness, rotation, and even being pulled out after long-term use. And because it cannot be integrally potted inside, its anti-vibration and anti-impact capabilities are weak, and it is easy to have a short-circuit failure, resulting in low product reliability. Summary of the Invention

[0004] The purpose of the present invention is to provide a π-type tubular filter, aiming to solve the technical problems in the prior art that the terminals are prone to rotation, falling off, and the overall filter has weak anti-vibration and anti-impact capabilities.

[0005] To achieve the above purpose, the technical solution adopted by the present invention is: providing a π-type tubular filter, including:

[0006] A tube shell;

[0007] An inductor, disposed inside the tube shell;

[0008] A capacitor assembly, disposed inside the tube shell. The capacitor assembly includes a circuit board and a chip capacitor electrically connected to the circuit board. The capacitor assembly is disposed on both sides of the inductor;

[0009] An input terminal and an output terminal, respectively disposed at both ends of the tube shell. An electrical connection is formed between the input terminal, the capacitor assembly, the inductor, and the output terminal to form a π-type filtering circuit. A first colloid is integrally potted inside the tube shell, and the insertion parts of the input terminal and the output terminal are potted in a second colloid. The second colloid is used to seal both ends of the tube shell. The insertion parts of the input terminal and the output terminal are limiting structures that prevent pulling and rotation.

[0010] In some embodiments of the present invention, the capacitor assembly includes a first capacitor assembly and a second capacitor assembly. The input terminal is electrically connected to the first capacitor assembly and the first end of the inductor. The second end of the first capacitor assembly is electrically connected to the tube shell to achieve grounding. The second end of the inductor is electrically connected to the output terminal and the first end of the second capacitor assembly. The second end of the second capacitor assembly is electrically connected to the tube shell to achieve grounding.

[0011] In some embodiments of the present invention, the input terminal and the output terminal include a pull ring portion and an insertion portion. The insertion portion includes a semi-circular ring portion with a semi-circular cross-section connected to the pull ring portion and a tubular portion connected to the semi-circular ring portion. The tubular portion further has an axial notch communicating both ends, and a boss structure is formed at the junction of the semi-circular ring portion and the insertion portion.

[0012] In some embodiments of the present invention, the capacitor assembly and the inductor are separated by an insulating board, and a first through hole for the first colloid to flow through is formed on the insulating board.

[0013] In some embodiments of the present invention, a second through hole for the first colloid to flow through is formed on the circuit board of the capacitor assembly, and the side of the circuit board where the chip capacitor is provided faces the inductor.

[0014] In some embodiments of the present invention, a first magnetic bead is provided between the circuit board and the corresponding insulating board. The first magnetic bead is clamped between the circuit board and the insulating board, and there is a gap between the chip capacitor and the insulating board.

[0015] In some embodiments of the present invention, a second magnetic bead is provided between the circuit board and the second colloid. The second magnetic bead is used to locate the lead-out positions of the input terminal and / or the output terminal.

[0016] In some embodiments of the present invention, internal threads are provided on the inner walls at both ends of the shell, and the internal threads are used to prevent the second colloid from falling off.

[0017] In some embodiments of the present invention, the first colloid is A / B glue, and the second colloid is G500 glue.

[0018] In some embodiments of the present invention, the first colloid is potted in the area between the two circuit boards of the two capacitor assemblies.

[0019] The beneficial effects of the π-shaped tubular filter provided by the present invention are as follows: Compared with the prior art, the filter of the present invention has a capacitor assembly, which assembles the chip capacitor and the circuit board together to form a capacitor assembly, and the inside of the shell is integrally potted with the first colloid. The chip capacitor is wrapped in the first colloid, so that the chip capacitor cannot contact the inner wall of the shell, and the stress from the shell direction is borne by the circuit board, making the chip capacitor have good stability, vibration resistance, and shock resistance. In addition, a second colloid is provided to seal both ends of the shell. The input terminal and the output terminal have a limiting structure, and through the limiting structure potted inside the second colloid, it is possible to prevent the input terminal and the output terminal from rotating and being pulled out. Description of the Drawings

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0021] Figure 1 Schematic structural diagram of the π-shaped tubular filter provided by the embodiment of the present invention;

[0022] Figure 2 Schematic circuit diagram of the π-shaped tubular filter provided by the embodiment of the present invention;

[0023] Figure 3 Schematic structural diagram of the capacitor assembly of the π-shaped tubular filter provided by the embodiment of the present invention;

[0024] Figure 4 For Figure 3 Schematic back structure diagram;

[0025] Figure 5 Schematic structural diagram of the insulating plate of the π-shaped tubular filter provided by the embodiment of the present invention;

[0026] Figure 6 Schematic structural diagram of the input terminal / output terminal of the π-shaped tubular filter provided by the embodiment of the present invention.

[0027] In the figure: 1, shell; 2, inductor; 3, capacitor assembly; 4, circuit board; 5, chip capacitor; 6, input terminal; 7, output terminal; 8, first colloid; 9, second colloid; 10, pull ring part; 11, semi-ring part; 12, tubular part; 13, axial notch; 14, insulating plate; 15, first through hole; 16, second through hole; 17, surface electrode; 18, center electrode; 19, back electrode; 20, first magnetic bead; 21, second magnetic bead. Detailed implementation manners

[0028] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the following further details the present invention in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] It should be noted that when an element is referred to as "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0030] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined. "Several" means one or more unless otherwise specifically defined.

[0031] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "center", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present invention.

[0032] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and may be the internal communication of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] Please refer to Figure 1 and Figure 2 , an embodiment of a π-shaped tubular filter provided by the present invention includes a tube shell 1, an inductor 2, a capacitor assembly 3, an input terminal 6, and an output terminal 7. The inductor 2 is disposed inside the tube shell 1; the capacitor assembly 3 is disposed inside the tube shell 1, and the capacitor assembly 3 includes a circuit board 4 and a chip capacitor 5 electrically connected to the circuit board 4. The capacitor assembly 3 is disposed on both sides of the inductor 2. The input terminal 6 and the output terminal 7 are disposed at both ends of the tube shell 1. An electrical connection is formed among the input terminal 6, the capacitor assembly 3, the inductor 2, and the output terminal 7 to form a π-shaped filter circuit. A first colloid 8 is integrally potted inside the tube shell 1, and the insertion portions of the input terminal 6 and the output terminal 7 are potted in a second colloid 9. The second colloid 9 is used to seal both ends of the tube shell 1, and the insertion portions of the input terminal 6 and the output terminal 7 are limiting structures that prevent pulling and rotation.

[0034] In this embodiment, the casing 1 is a cylindrical housing, preferably made of metal. Inside the casing 1, there are an inductor 2 and a capacitor assembly 3. The capacitor assembly 3 is in the form of a combination of a circuit board 4 and a chip capacitor 5. The chip capacitor 5 can be an ordinary ceramic chip capacitor 5, integrated into the PCB capacitor assembly 3. The capacitor assemblies 3 are arranged on both sides of the inductor 2. Preferably, there are two capacitor assemblies 3, which are respectively arranged on both sides of the inductor 2, facilitating the connection into a π-type filter circuit. The inductor 2 is arranged at the central position inside the casing 1, with a capacitor assembly 3 on each side. The inside of the casing 1 is integrally potted with a first colloid 8 to wrap all the components, especially the chip capacitor 5, enabling it to be vibration-proof, shock-proof, and maintain stability. Moreover, the chip capacitor 5 does not contact the inner wall of the casing 1. It is the circuit board 4 that contacts the inner wall of the casing 1, and the circuit board 4 bears the pressure from the direction of the casing 1, which better protects the chip capacitor 5. The two ends of the casing 1 are sealed with a second colloid 9. Inside the second colloid 9, an input terminal 6 and an output terminal 7 are respectively inserted. The second colloid 9 is hermetically bonded to the inner wall of the casing 1, with good stability, anti-pull-out, and anti-rotation properties. Additionally, to prevent the input terminal 6 and the output terminal 7 from rotating relative to the second colloid 9, the insertion parts of the input terminal 6 and the output terminal 7 are configured in a structural form that can prevent pull-out and rotation, thus effectively preventing the input terminal 6 and the output terminal 7 from being pulled out and rotating relative to the second colloid 9.

[0035] This filter has a capacitor assembly 3, which assembles the chip capacitor 5 and the circuit board 4 together to form the capacitor assembly 3. And the inside of the casing 1 is integrally potted with a first colloid 8. The chip capacitor 5 is wrapped inside the first colloid 8, so that the chip capacitor 5 does not contact the inner wall of the casing 1. The stress from the direction of the casing 1 is borne by the circuit board 4, making the chip capacitor 5 have good stability, vibration resistance, and shock resistance. Also, there is a second colloid 9 for sealing the two ends of the casing 1. The input terminal 6 and the output terminal 7 have a limiting structure, and through the limiting structure, they are potted inside the second colloid 9, which can prevent the input terminal 6 and the output terminal 7 from rotating and being pulled out.

[0036] As Figure 2 shown, regarding the capacitor assembly 3, in order to be applicable to the π-type filter circuit, the capacitor assembly 3 includes a first capacitor assembly and a second capacitor assembly. The input terminal 6 is electrically connected to the first capacitor assembly and the first end of the inductor 2. The second end of the first capacitor assembly is electrically connected to the casing 1 to achieve grounding. The second end of the inductor 2 is electrically connected to the output terminal 7 and the first end of the second capacitor assembly. The second end of the second capacitor assembly is electrically connected to the casing 1 to achieve grounding. Through the above electrical connection form, the first capacitor assembly, the second capacitor assembly, the inductor 2, the output terminal 7, and the input terminal 6 form a π-type filter circuit.

[0037] As Figure 3 andFigure 4 As shown, specifically, two surface electrodes 17 for connecting the chip capacitor 5 are provided on the front of the circuit board 4, and a chip capacitor 5 is connected between the two surface electrodes 17. The chip capacitor 5 is connected to the circuit, and then a center electrode 18 is provided at the center position of the circuit board 4. A back electrode 19 for connecting the takeover shell 1, i.e., grounding, is provided on the back of the circuit board 4. In a specific embodiment, it is connected as follows: the input terminal 6 is connected to the center electrode 18, the center electrode 18 is connected to the surface electrode 17, and the surface electrode 17 is connected to the back electrode 19. In this way, the chip capacitor 5 is connected to the circuit and grounded, and the surface electrode 17 is then connected to the inductor 2. After passing through the inductor 2, it is connected to the chip capacitor 5 on another capacitor component 3 in the same manner and grounded, and finally connected to the output terminal 7. It should be noted that two parallel chip capacitors 5 can be provided on a circuit board 4, and the two chip capacitors 5 can be connected to the circuit at the same time, so four surface electrodes 17 and two back electrodes 19 can be provided accordingly to connect the two chip capacitors 5 to the circuit and ground respectively. The number of chip capacitors 5 on the circuit board 4 can be set according to actual needs, and appropriate electrodes and access forms can be set on the circuit board 4 accordingly.

[0038] like Figure 6 As shown, in order to prevent the input terminal 6 and the output terminal 7 from being pulled out and rotated inside the second colloid 9, in this embodiment, the input terminal 6 and the output terminal 7 include a pull ring portion 10 and an insertion portion, and the insertion portion includes a semi-annular portion 11 with a semi-annular cross-section connected to the pull ring portion 10 and a tubular portion 12 connected to the semi-annular portion 11. The tubular portion 12 also has an axial notch 13 connecting the two ends, and a boss structure is formed at the junction of the semi-annular portion 11 and the insertion portion.

[0039] In this embodiment, the pull ring portion 10 can be used for wiring, and the insertion portion includes a semi-annular portion 11 and a tubular portion 12. The semi-annular portion 11 can prevent the terminal from rotating within the second colloid 9. A boss structure is provided between the tubular portion 12 and the semi-annular portion 11, that is, the tubular portion 12 has a larger annular cross-section than the semi-annular portion 11, and the larger cross-section at one end forms a boss structure, which can prevent the terminal from being pulled out. In addition, an axial notch 13 is provided on the tubular portion 12, which can facilitate the inflow of the second colloid 9 and ensure that the interior of the tubular portion 12 is filled with the second colloid 9. Therefore, the terminal shape of this embodiment can effectively prevent the terminal from being pulled out or rotating within the second colloid 9.

[0040] like Figure 1 and Figure 5 As shown, in one embodiment of the present invention, the capacitor component 3 and the inductor 2 are separated by an insulating plate 14 , and a first through hole 15 for the first colloid 8 to flow through is defined in the insulating plate 14 .

[0041] In this embodiment, the insulating plate 14 is used to separate the capacitor assembly 3 and the inductor 2 from each other to reduce the electromagnetic interference between the capacitor assembly 3 and the inductor 2. The insulating plate 14 can also be made of a PCB. The shapes of the insulating plate 14 and the circuit board 4 of the capacitor assembly 3 are both adapted to the inner cross-section of the tube case 1. They are arranged in the tube case 1 along the radial direction of the tube case 1 and their edges contact the inner wall of the tube case 1. Both the insulating plate 14 and the circuit board 4 can withstand pressure from the inner wall of the tube case 1. A first through hole 15 is provided in the insulating plate 14 to facilitate the flow of the first colloid 8.

[0042] Specifically, the first through hole 15 may be a notch provided at the edge of the insulating plate 14 .

[0043] like Figure 3 and Figure 4 To allow the first colloid 8 to pass smoothly, a second through-hole 16 for the first colloid 8 to flow through is also provided on the circuit board 4 of the capacitor assembly 3. This allows the first colloid 8 to fill the entire inner cavity. The side of the circuit board 4 with the chip capacitor 5 facing the inductor 2. The first colloid 8 is filled between the two circuit boards 4, effectively enveloping the chip capacitor 5.

[0044] like Figure 1 As shown, in order to prevent the chip capacitor 5 from bearing stress from the insulating plate 14, a first magnetic bead 20 is provided between the circuit board 4 and the insulating plate 14 on the corresponding side. The first magnetic bead 20 is sandwiched between the circuit board 4 and the insulating plate 14, and there is a gap between the chip capacitor 5 and the insulating plate 14.

[0045] In this embodiment, a first magnetic bead 20 is provided. The first magnetic bead 20 is provided between the circuit board 4 and the insulating plate 14, which is equivalent to supporting the insulating plate 14 and the circuit board 4 on both sides respectively. The chip capacitor 5 is shorter than the first magnetic bead 20, so there is a gap between it and the insulating plate 14, preventing the chip capacitor 5 from bearing stress from the direction of the insulating plate 14, thereby effectively protecting the chip capacitor 5.

[0046] A second magnetic bead 21 is provided between the circuit board 4 and the second colloid 9 . The second magnetic bead 21 is used to locate the lead-out position of the input terminal 6 and / or the output terminal 7 .

[0047] Specifically, a second magnetic bead 21 is provided and placed between the circuit board 4 and the second colloid 9. That is, the length of the second magnetic bead 21 determines the filling depth of the second colloid 9 and the lead-out position of the output terminal 7 or the input terminal 6, so that the lead-out position can be better controlled, the lead-out end can be successfully welded in one go, and the product assembly efficiency can be improved.

[0048] Both the first magnetic bead 20 and the second magnetic bead 21 can withstand the stress from the terminal direction, avoiding the stress extrusion on the chip capacitor 5. The stress generated by tests such as random vibration, high-frequency vibration, low-frequency vibration, and shock is borne by the circuit board 4, the first magnetic bead 20, and the second magnetic bead 21, so as to achieve the purpose of protecting the chip capacitor 5. The first magnetic bead 20 and the second magnetic bead 21 not only protect the chip capacitor 5, but also improve the high-frequency characteristics of the product.

[0049] In order to prevent the second colloid 9 from coming out, internal threads are provided on the inner walls at both ends of the shell 1, and the internal threads are used to prevent the second colloid 9 from falling off. This embodiment adopts a special structural design, combined with the internal thread structure of the shell 1, which has the functions of preventing the lead-out end from rotating and falling off, and the internal thread structure has the functions of preventing pulling out and preventing water vapor.

[0050] The first colloid 8 can be selected as A / B glue. The first colloid 8 is potted in the area between the two circuit boards 4 of the two capacitor components 3. The second colloid 9 can be selected as G500 glue. G500 glue begins to soften only when the temperature reaches 400 °C and can resist high-temperature soldering.

[0051] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A π-type tubular filter, characterized in that, Comprising: A shell; An inductor disposed within the shell; A capacitor assembly disposed within the shell, the capacitor assembly comprising a circuit board and a chip capacitor electrically connected to the circuit board, the capacitor assembly being disposed on both sides of the inductor; An input terminal and an output terminal disposed at both ends of the shell, an electrical connection is formed between the input terminal, the capacitor assembly, the inductor, and the output terminal to form a π-type filter circuit. A first colloid is potted integrally within the shell, and the insertion portions of the input terminal and the output terminal are potted within a second colloid. The second colloid is used to seal both ends of the shell. The insertion portions of the input terminal and the output terminal are limit structures that prevent pulling and rotation. The capacitor assembly includes a first capacitor assembly and a second capacitor assembly. The input terminal is electrically connected to the first capacitor assembly and the first end of the inductor. The second end of the first capacitor assembly is electrically connected to the shell to achieve grounding. The second end of the inductor is electrically connected to the output terminal and the first end of the second capacitor assembly. The second end of the second capacitor assembly is electrically connected to the shell to achieve grounding. The first capacitor assembly, the second capacitor assembly, the inductor, the output terminal, and the input terminal form a π-type filter circuit. The input terminal and the output terminal include a pull ring portion and an insertion portion. The insertion portion includes a semi-circular ring portion with a semi-circular cross-section connected to the pull ring portion and a tubular portion connected to the semi-circular ring portion. The tubular portion also has an axial notch communicating both ends. A boss structure is formed at the junction of the semi-circular ring portion and the insertion portion. The capacitor assembly and the inductor are separated by an insulating board, and a first through hole for the first colloid to flow through is provided on the insulating board.

2. The π-type tubular filter according to claim 1, characterized in that, A second through hole for the first colloid to flow through is provided on the circuit board of the capacitor assembly, and the side of the circuit board where the chip capacitor is provided faces the inductor.

3. The π-type tubular filter according to claim 1, characterized in that, A first magnetic bead is provided between the circuit board and the corresponding insulating board. The first magnetic bead is clamped between the circuit board and the insulating board, and there is a gap between the chip capacitor and the insulating board.

4. The π-type tubular filter according to claim 3, wherein, A second magnetic bead is provided between the circuit board and the second colloid. The second magnetic bead is used to locate the lead-out positions of the input terminal and / or the output terminal.

5. The π-type tubular filter according to claim 1, wherein, Internal threads are provided on the inner walls at both ends of the shell, and the internal threads are used to prevent the second colloid from falling off.

6. The π-type tubular filter according to claim 1, characterized in that, The first colloid is A / B glue, and the second colloid is G500 glue.

7. The π-type tubular filter according to claim 1, characterized in that, The first colloid is potted within the region between the two circuit boards of the two capacitor assemblies.

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