CN113225040A

CN113225040A - Pi-shaped tubular filter

Info

Publication number: CN113225040A
Application number: CN202110591553.9A
Authority: CN
Inventors: 蒋忠益; 肖倩; 刘季超; 王胜刚; 李金辉; 王智会
Original assignee: Shenzhen Zhenhua Ferrite and Ceramic Electronics Co Ltd
Current assignee: Shenzhen Zhenhua Ferrite and Ceramic Electronics Co Ltd
Priority date: 2021-05-28
Filing date: 2021-05-28
Publication date: 2021-08-06

Abstract

The invention is suitable for the technical field of military filtering equipment, in particular to a pi-shaped tubular filter, which comprises a tube shell, an inductor, a capacitor assembly, an input terminal and an output terminal, wherein the tube shell is provided with a first end and a second end; the inductor is arranged in the tube shell; the capacitor assembly is arranged in the tube shell and comprises a circuit board and a patch capacitor electrically connected to the circuit board, and the capacitor assembly is respectively arranged on two sides of the inductor; input terminal and output terminal divide the both ends of locating the tube, and electric connection forms pi type filter circuit between input terminal, capacitor assembly, inductor and the output terminal, wholly embedment first colloid in the tube, and the portion of inserting of input terminal and output terminal embedment is in the second colloid, and the second colloid is used for the both ends of sealed tube, and the portion of inserting of input terminal and output terminal is for hindering drawing and pivoted limit structure. The technical problems that the terminal is easy to rotate and fall off and the whole filter is weak in vibration resistance and impact resistance in the prior art are solved.

Description

Pi-shaped tubular filter

Technical Field

The invention relates to the technical field of military filtering equipment, in particular to a pi-shaped tubular filter.

Background

The filter is a filter circuit consisting of a capacitor, an inductor and a resistor. The filter can effectively filter the frequency point of the specific frequency in the power line or the frequencies except the frequency point to obtain a power signal of the specific frequency or eliminate the power signal of the specific frequency.

The pi-type filter is a commonly used filter, the traditional pi-type tubular filter has the problems of terminal rotation and terminal pulling-out, the interior cannot be integrally encapsulated, the terminal is easy to loosen and rotate or even be pulled out under long-term use, and the interior cannot be integrally encapsulated, so that the filter is weak in vibration resistance and impact resistance, the capacitor is easy to short-circuit failure, and the reliability of the product is low.

Disclosure of Invention

The invention aims to provide a pi-shaped tubular filter, and aims to solve the technical problems that a terminal is easy to rotate and fall off and the whole filter is weak in vibration resistance and impact resistance in the prior art.

In order to achieve the purpose, the invention adopts the technical scheme that: provided is a pi-type tubular filter including:

a pipe shell;

the inductor is arranged in the tube shell;

the capacitor assembly is arranged in the tube shell and comprises a circuit board and a patch capacitor electrically connected to the circuit board, and the capacitor assembly is respectively arranged on two sides of the inductor;

the input terminal and the output terminal are respectively arranged at two ends of the tube shell, the input terminal, the capacitor assembly, the inductor and the output terminal are electrically connected to form a pi-shaped filter circuit, the tube shell is internally and integrally encapsulated with a first colloid, the input terminal and the insertion part of the output terminal are encapsulated in a second colloid, the second colloid is used for sealing two ends of the tube shell, and the insertion part of the input terminal and the insertion part of the output terminal are of a limiting structure for preventing drawing and rotating.

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 case for grounding, the second end of the inductor is electrically connected to the output terminal and the first end of the second capacitor assembly, and the second end of the second capacitor assembly is electrically connected to the case for grounding.

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-ring portion connected to the pull ring portion and having a semi-ring shape in cross section, and a tubular portion connected to the semi-ring portion, the tubular portion further has an axial gap communicating the two ends, and a boss structure is formed at the joint of the semi-ring portion and the insertion portion.

In some embodiments of the present invention, the capacitor assembly and the inductor are separated by an insulating plate, and the insulating plate is provided with a first through hole for flowing the first glue.

In some embodiments of the present invention, a circuit board of the capacitor assembly is provided with a second through hole for flowing the first adhesive, and one side of the circuit board on which the chip capacitor is disposed faces the inductor.

In some embodiments of the invention, a first magnetic bead is arranged between the circuit board and the insulating board on the corresponding side, the first magnetic bead is clamped between the circuit board and the insulating board, and a gap is formed between the patch capacitor and the insulating board.

In some embodiments of the present invention, a second magnetic bead is disposed between the circuit board and the second colloid, and the second magnetic bead is used to position the leading-out position of the input terminal and/or the leading-out position of the output terminal.

In some embodiments of the present invention, internal threads are provided on the inner walls of both ends of the tube shell, and the internal threads are used for preventing the second colloid from falling off.

In some embodiments of the present invention, the first colloid is an a/B glue, and the second colloid is a G500 glue.

In some embodiments of the invention, the first glue is potted in an area between two circuit boards of two capacitive assemblies.

The pi-shaped tubular filter provided by the invention has the beneficial effects that: compared with the prior art, the filter provided by the invention is provided with the capacitor assembly, the chip capacitor and the circuit board are assembled together to form the capacitor assembly, the first colloid is adopted in the pipe shell to carry out integral encapsulation, the chip capacitor is wrapped in the first colloid, so that the chip capacitor cannot contact with the inner wall of the pipe shell, and the stress from the direction of the pipe shell is borne by the circuit board, so that the chip capacitor has good stability, vibration resistance and impact resistance.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed for the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a pi-type tubular filter according to an embodiment of the present invention;

FIG. 2 is a schematic circuit diagram of a pi-type tubular filter according to an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a capacitance component of a pi-type tubular filter according to an embodiment of the present invention;

FIG. 4 is a schematic view of the back structure of FIG. 3;

fig. 5 is a schematic structural diagram of an insulating plate of a pi-type tubular filter according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of an input terminal/an output terminal of a pi-type tubular filter according to an embodiment of the present invention.

In the figure: 1. a pipe shell; 2. an inductor; 3. a capacitive component; 4. a circuit board; 5. a chip capacitor; 6. an input terminal; 7. an output terminal; 8. a first colloid; 9. a second colloid; 10. a pull ring part; 11. a semi-ring portion; 12. a tubular portion; 13. an axial gap; 14. an insulating plate; 15. a first through hole; 16. a second through hole; 17. a surface electrode; 18. a center electrode; 19. a back electrode; 20. a first magnetic bead; 21. and a second magnetic bead.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present invention more clearly apparent, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise. The meaning of "a number" is one or more unless specifically limited otherwise.

In the description of the present invention, it is to be understood that the terms "center", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Referring to fig. 1 and 2, the present invention provides an embodiment of a pi-type tubular filter, including a case 1, an inductor 2, a capacitor assembly 3, an input terminal 6, and an output terminal 7, where the inductor 2 is disposed in the case 1; capacitor assembly 3 locates in tube 1, and capacitor assembly 3 includes circuit board 4 and the paster electric capacity 5 of electric connection on circuit board 4, capacitor assembly 3 divides to locate inductor 2's both sides, and input terminal 6 and output terminal 7 divide the both ends of locating tube 1, electric connection forms pi type filter circuit between input terminal 6, capacitor assembly 3, inductor 2 and the output terminal 7 wholly embedment first colloid 8 in tube 1, the embedment of the portion of inserting of input terminal 6 and output terminal 7 is in second colloid 9, second colloid 9 is used for sealed tube 1's both ends, the portion of inserting of input terminal 6 and output terminal 7 is for hindering drawing and pivoted limit structure.

In this embodiment, the tube case 1 is a cylindrical case, which is preferably made of metal, the inductor 2 and the capacitor assembly 3 are disposed inside the tube case 1, the capacitor assembly 3 is formed by combining a circuit board 4 and a chip capacitor 5, the chip capacitor 5 can be a common ceramic chip capacitor 5 integrated into a PCB capacitor assembly 3, the capacitor assembly 3 is disposed on two sides of the inductor 2, preferably two capacitor assemblies 3 are disposed on two sides of the inductor 2 respectively, so as to connect into a pi-filter circuit, the inductor 2 is disposed in a central position inside the tube case 1, two sides are respectively a capacitor assembly 3, a first colloid 8 is integrally encapsulated in the tube case 1, and wraps each component, particularly wraps the chip capacitor 5, so that the chip capacitor 5 can prevent vibration, impact and maintain stability, and the chip capacitor 5 does not contact with the inner wall of the tube case 1, and contacts with the circuit board 4, circuit board 4 bears the pressure of tube 1 direction, the more favourable deprotection paster electric capacity 5, the both ends of tube 1 are sealed through second colloid 9, input terminal 6 and output terminal 7 are inserted respectively to second colloid 9 inside, second colloid 9 bonds with the inner wall seal of tube 1, stability is good, prevent drawing and rotating, in addition in order to prevent that input terminal 6 and output terminal 7 are relative second colloid 9 to rotate, then set to the portion of inserting at input terminal 6 and output terminal 7 and can hinder drawing and pivoted structural style, can be fine like this prevent that input terminal 6 and output terminal 7 from taking place to draw and rotating relatively second colloid 9.

This wave filter has capacitor assembly 3, it is in the same place paster electric capacity 5 and circuit board 4 assembly, form capacitor assembly 3, and the inside of tube 1 adopts first colloid 8 to carry out the form of whole embedment, paster electric capacity 5 parcel is in first colloid 8, make paster electric capacity 5 contact the inner wall of tube 1, the stress that comes from 1 direction of tube is born by circuit board 4, make paster electric capacity 5 have fine stability, vibration resistance, shock resistance, and still be equipped with second colloid 9, a both ends for sealing tube 1, input terminal 6 and output terminal 7 have limit structure, encapsulate inside second colloid 9 through limit structure, can prevent that input terminal 6 and output terminal 7 from rotating and extracting.

As shown in fig. 2, in order to be applied to a filter circuit configured as a pi filter circuit, the capacitor module 3 includes a first capacitor module and a second capacitor module, the input terminal 6 is electrically connected to the first capacitor module and the first end of the inductor 2, the second end of the first capacitor module is electrically connected to the case 1 for grounding, the second end of the inductor 2 is electrically connected to the output terminal 7 and the first end of the second capacitor module, and the second end of the second capacitor module is electrically connected to the case 1 for grounding. Through the above-mentioned electrical connection, the first capacitor element, the second capacitor element, the inductor 2, the output terminal 7, and the input terminal 6 form a pi-type filter circuit.

As shown in fig. 3 and 4, specifically, two surface electrodes 17 for connecting the patch capacitors 5 are provided on the front surface of the circuit board 4, one patch capacitor 5 is connected between the two surface electrodes 17, the patch capacitor 5 is connected to the circuit, then a center electrode 18 is provided at the center position of the circuit board 4, on the back side of the circuit board 4, a back electrode 19 for the connector housing 1, i.e. the ground, is provided, which, in the specific embodiment, which is connected such that the input terminal 6 is connected to the central electrode 18, the central electrode 18 is connected to the surface electrode 17, the surface electrode 17 is connected to the back electrode 19, which connects the patch capacitor 5 in the circuit and achieves grounding, the surface electrode 17 is connected to the inductor 2, and after passing through the inductor 2, the surface electrode is connected to the patch capacitor 5 of the other capacitor unit 3 in the same manner to ground, and finally connected to the output terminal 7. It should be noted that two patch capacitors 5 connected in parallel may be disposed on one circuit board 4, and the two patch capacitors 5 may be simultaneously connected to the circuit, so that four surface electrodes 17 and two back electrodes 19 may be correspondingly disposed, and the two patch capacitors 5 may be connected to the circuit and grounded, respectively. The number of the patch capacitors 5 on the circuit board 4 can be set according to actual needs, and adaptive electrodes and access forms are correspondingly arranged on the circuit board 4.

As shown in fig. 6, in order to prevent the input terminal 6 and the output terminal 7 from being pulled 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, the insertion portion includes a semi-ring portion 11 connected with the pull ring portion 10 and having a semi-ring shape in cross section and a tubular portion 12 connected with the semi-ring portion 11, the tubular portion 12 further has an axial gap 13 communicating two ends, and a boss structure is formed at the joint of the semi-ring portion 11 and the insertion portion.

In this embodiment, the pull ring part 10 can be used for wiring, the insertion part includes a half ring part 11 and a tubular part 12, the half ring part 11 can prevent the terminal from rotating in the second colloid 9, a boss structure is provided between the tubular part 12 and the half ring part 11, that is, the tubular part 12 is larger than the annular section of the half ring part 11, the larger end section forms the boss structure, the terminal can be prevented from being pulled out, and an axial gap 13 is further provided on the tubular part 12, which can facilitate the second colloid 9 to flow in, and ensure that the inside of the tubular part 12 is filled with the second colloid 9. The terminal shape of the present embodiment can prevent the terminal from being pulled out or rotated in the second colloid 9.

As shown in fig. 1 and 5, in one embodiment of the present invention, the capacitor assembly 3 and the inductor 2 are separated by an insulating plate 14, and the insulating plate 14 is provided with a first through hole 15 for the first colloid 8 to flow through.

In this embodiment, the insulating plate 14 is used for separating the capacitor module 3 and the inductor 2 from each other, so as to reduce the electromagnetic interference effect between the capacitor module 3 and the inductor 2, the insulating plate 14 may also be a PCB, the shapes of the insulating plate 14 and the circuit board 4 of the capacitor module 3 are both adapted to the inner cross section of the tube case 1, the insulating plate is disposed in the tube case 1 along the radial direction of the tube case 1, and the edge of the insulating plate contacts with the inner wall of the tube case 1, the insulating plate 14 and the circuit board 4 can bear the pressure from the inner wall direction of the tube case 1, and the insulating plate 14 is provided with a first through hole 15, so that the first colloid 8 can flow through the insulating plate.

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

As shown in fig. 3 and 4, in order to allow the first glue 8 to pass through smoothly, a second through hole 16 is also formed in the circuit board 4 of the capacitor module 3 for the first glue 8 to flow through, so that the first glue 8 can fill the whole inner cavity, and the side of the circuit board 4 on which the patch capacitor 5 is disposed faces the inductor 2. First colloid 8 filling is between two circuit boards 4, can be fine live paster electric capacity 5 parcel.

As shown in fig. 1, in order to prevent the patch capacitor 5 from receiving 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 a gap is provided between the patch capacitor 5 and the insulating plate 14.

In this embodiment, the first magnetic bead 20 is disposed between the circuit board 4 and the insulating board 14, which is equivalent to that the two sides of the first magnetic bead 20 respectively support the insulating board 14 and the circuit board 4, and the patch capacitor 5 is shorter than the first magnetic bead 20, so that a gap is formed between the first magnetic bead and the insulating board 14, and the patch capacitor 5 is prevented from bearing stress from the direction of the insulating board 14, thereby effectively protecting the patch capacitor 5.

And a second magnetic bead 21 is arranged between the circuit board 4 and the second colloid 9, and the second magnetic bead 21 is used for positioning the leading-out position of the input terminal 6 and/or the output terminal 7.

Specifically, set up second magnetic bead 21, second magnetic bead 21 is placed between circuit board 4 and second colloid 9, and the length of second magnetic bead 21 has also decided the filling depth of second colloid 9 and output terminal 7 or input terminal 6's leading-out position, makes the control leading-out position that can be better, will draw out the end welding and decide once successfully, improves product assembly efficiency.

First magnetic bead 20 and second magnetic bead 21 all can bear the stress that comes from the terminal direction, avoid paster electric capacity 5 to receive stress extrusion, and the stress that tests such as random vibration, high-frequency vibration, low-frequency vibration, impact produced is born by circuit board 4 and first magnetic bead 20, second magnetic bead 21 to reach the purpose of protection paster electric capacity 5. The first magnetic bead 20 and the second magnetic bead 21 not only protect the patch capacitor 5, but also improve the high-frequency characteristics of the product.

In order to prevent the second colloid 9 from falling off, internal threads are arranged on the inner walls of the two ends of the pipe shell 1, and the internal threads are used for preventing the second colloid 9 from falling off. This embodiment adopts special structural design, and cooperation shell 1 internal thread structure has the effect of drawing forth the end and preventing rotation and drop, and internal thread structure has the effect of preventing pulling out and preventing steam.

The first glue body 8 can be selected to be A/B glue, the first glue body 8 is encapsulated in the area between the two circuit boards 4 of the two capacitor assemblies 3, and the second glue body 9 can be selected to be G500 glue. The G500 adhesive begins to soften after the temperature reaches 400 ℃, and can resist high-temperature welding.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.

Claims

1. A pi-type tubular filter, comprising:

a pipe shell;

the inductor is arranged in the tube shell;

2. A pi-type tubular filter as claimed in claim 1, wherein the capacitor assembly comprises 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 case for grounding, the second end of the inductor is electrically connected to the output terminal and the first end of the second capacitor assembly, and the second end of the second capacitor assembly is electrically connected to the case for grounding.

3. A pi-type tubular filter as claimed in claim 1 or 2, wherein the input and output terminals include a pull ring portion and an insertion portion, the insertion portion includes a semi-ring portion connected to the pull ring portion and having a semi-ring shape in cross section and a tubular portion connected to the semi-ring portion, the tubular portion further has an axial gap communicating the two ends, and a boss structure is formed at the junction of the semi-ring portion and the insertion portion.

4. A pi-type tubular filter as claimed in claim 1, wherein the capacitor module and the inductor are separated by an insulating plate, and the insulating plate is provided with a first through hole for a first gel to flow through.

5. The pi-type tubular filter according to claim 1, wherein a circuit board of the capacitor assembly is provided with a second through hole for the first adhesive to flow through, and a side of the circuit board on which the patch capacitor is provided faces the inductor.

6. The pi-type tubular filter according to claim 4, wherein a first magnetic bead is provided between the circuit board and an insulating plate on a corresponding side, the first magnetic bead being sandwiched between the circuit board and the insulating plate, and the chip capacitor and the insulating plate having a gap therebetween.

7. The pi-type tubular filter according to claim 6, wherein a second magnetic bead is provided between the circuit board and the second colloid, and the second magnetic bead is used for positioning a leading-out position of the input terminal and/or the output terminal.

8. A pi-type tubular filter as claimed in claim 1, wherein internal threads are provided on the inner walls of both ends of the tube case, the internal threads being for preventing the second colloid from falling off.

9. A pi-type tubular filter as claimed in claim 1, wherein the first gel is an a/B gel and the second gel is a G500 gel.

10. A pi-type tubular filter as claimed in claim 2, wherein the first glue is potted in an area between two circuit boards of two capacitor assemblies.