CN219371314U - Filter - Google Patents

Abstract

The utility model relates to the technical field of communication equipment, and provides a filter, which comprises a cavity, a cover plate, a signal transmission piece and a limiting structure, wherein the cover plate covers the cavity, the limiting structure is arranged in the cavity and/or the cover plate, the limiting structure comprises a first limiting piece and a second limiting piece, the first limiting piece is connected with the second limiting piece through interference fit, and the first limiting piece and/or the second limiting piece clamp and fix the signal transmission piece. In the high-low temperature environment, the first limiting piece and the second limiting piece are connected through interference fit, the first limiting piece and the second limiting piece expand or contract synchronously, looseness does not occur between the first limiting piece and the second limiting piece, the signal transmission piece clamped and fixed by the first limiting piece and/or the second limiting piece does not loosen, the technical problem that the signal transmission piece in the existing filter is easy to loosen is solved, and therefore the position stability of the signal transmission piece and the stability of the signal transmission are improved, and abnormal sound caused by looseness of the signal transmission piece is reduced.

Description

Filter

Technical Field

The utility model relates to the technical field of communication equipment, in particular to a filter.

Background

The filter is a device or circuit with a signal processing function, which mainly has the function of passing a useful signal as far as possible without attenuation, and attenuating an useless signal as far as possible, and is commonly used as a frequency selecting device for selecting a communication signal frequency and filtering clutter or interference signals outside the communication signal frequency, and is widely applied to a mobile base station to reduce intermodulation signal interference and generate a high-quality communication signal, thus being an indispensable device in an electronic communication system.

In the existing filter, two fixing blocks respectively abut against the upper surface and the lower surface of the signal transmission member at intervals to limit the up-down movement of the signal transmission member, so that the signal transmission member is fixed in the cavity. In the high-low temperature environment of the filter, the signal transmission piece is easy to loosen, so that abnormal sound is generated in the filter product.

Disclosure of Invention

The utility model aims to provide a filter and aims to solve the technical problem that a signal transmission part in the existing filter is easy to loosen.

The application provides a filter, the filter includes:

a cavity;

the cover plate covers the cavity;

a signal transmission member at least partially disposed in the cavity;

the limiting structure is arranged in the cavity and/or the cover plate, and comprises a first limiting part and a second limiting part, wherein the first limiting part is connected with the second limiting part through interference fit, and the first limiting part and/or the second limiting part is clamped and fixed on the signal transmission part.

In one embodiment, one of the first and second stop members has a recess in which the other of the first and second stop members is interference fit mounted.

In one embodiment, the first stop has the recess, and the end of the second stop is interference fit mounted in the recess.

In one embodiment, the second stop has the recess, and the end of the first stop is interference fit mounted in the recess.

In one embodiment, one of the first and second limiting members has a first limiting groove, a length direction of the first limiting groove is identical to a length direction of the signal transmission member, and the signal transmission member is supported in the first limiting groove.

In one embodiment, the other of the first limiting member and the second limiting member is provided with a second limiting groove, the length direction of the second limiting groove is consistent with the length direction of the signal transmission member, the opening of the first limiting groove and the opening of the second limiting groove are oppositely arranged, and the signal transmission member is supported in the second limiting groove.

In one embodiment, the first limit groove and the second limit groove are distributed at intervals along the length direction of the signal transmission member.

In one embodiment, the groove wall of the first limiting groove is attached to the outer surface of the signal transmission member.

In one embodiment, the signal transmission member has a first step surface, the first step surface is substantially perpendicular to the length direction of the signal transmission member, and the first step surface abuts against the side wall of the first limiting member and/or the second limiting member.

In one embodiment, the signal transmission member has a second step surface, the second step surface is substantially perpendicular to the length direction of the signal transmission member, and the first step surface and the second step surface are disposed opposite or opposite to each other.

In one embodiment, the first stop has a volume greater than the second stop;

the first limiting piece is arranged at the bottom of the cavity, or the second limiting piece is arranged at the bottom of the cavity.

In one embodiment, the number of the limiting structures is more than two, and the more than two limiting structures are distributed at intervals along the length direction of the signal transmission member.

The filter provided by the utility model has the beneficial effects that: the limiting structure is arranged in the cavity and/or the cover plate, the first limiting part and the second limiting part are connected through interference fit, and in a high-low temperature environment, the first limiting part and the second limiting part expand or contract synchronously, looseness does not occur between the first limiting part and the second limiting part, so that a signal transmission part clamped and fixed by the first limiting part and/or the second limiting part does not loosen, the technical problem that the signal transmission part in the existing filter is easy to loosen is solved, the position stability of the signal transmission part and the stability of the signal transmission are improved, and abnormal sound caused by looseness of the signal transmission part is reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the drawings that are needed in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present utility model, and that other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a filter according to an embodiment of the present utility model;

fig. 2 is a schematic diagram of an internal structure of a filter according to an embodiment;

FIG. 3 is an exploded view of a filter provided by an embodiment;

FIG. 4 is a cross-sectional view taken along line B-B of the filter of FIG. 1;

FIG. 5 is a cross-sectional view taken along line A-A of the filter of FIG. 1;

FIG. 6 is a cross-sectional view of the filter of FIG. 1 along line A-A in some embodiments;

fig. 7 is a cross-sectional view of the filter of fig. 1 along line A-A in some embodiments.

Wherein, each reference sign in the figure:

110. a cavity; 111. a signal inlet; 112. a signal outlet; 113. a mounting groove; 120. a cover plate;

200. a signal transmission member; 201. a first step surface; 202. a second step surface; 210. a large diameter section; 220. a small diameter section;

300. a limit structure; 310. a first limiting member; 311. a groove; 312. a first limit groove; 320. a second limiting piece; 321. a bump; 322. and the second limit groove.

Detailed Description

Embodiments of the present utility model are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative and intended to explain the present utility model and should not be construed as limiting the utility model.

Reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present application. Thus, the appearances of the phrase "in one embodiment" or "in some embodiments" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

In the description of the present utility model, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like indicate orientations or positional relationships based on the orientation or positional relationships shown in the drawings, merely to facilitate describing the present utility model and simplify the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present utility model.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature.

In the present utility model, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

A filter in an embodiment of the present utility model will now be described.

Referring to fig. 1 to 3, the filter includes a cavity 110, a cover plate 120, a signal transmission member 200, and a limiting structure 300.

For convenience of explanation of the embodiments of the present application, a first direction X, a second direction Y, and a third direction Z are defined, wherein the first direction X, the second direction Y, and the third direction Z are perpendicular to each other. The first direction X is parallel to the length direction of the signal transmission member 200, and the third direction Z is parallel to the height direction of the signal transmission member 200 within the cavity 110.

The cover plate 120 covers the cavity 110 to form a filtering cavity with a complete filtering channel and prevent signal leakage.

The signal transmission member 200 is at least partially disposed in the cavity 110. The signal transmission member 200 may be a tap, a tap rod, a tap wire, a connecting rod, a connecting sheet, a coupling plate, a metal sheet, a metal plate, a PCB board, a low pass, or the like having a function of transmitting a signal within the filter, which is not limited herein. The signal transmission member 200 is elongated. The signal transmission member 200 may be located entirely within the cavity 110, or the signal transmission member 200 may be located partially within the cavity 110, for example, one end of the signal transmission member 200 is located at the signal inlet 111 of the cavity 110, and the other end of the signal transmission member 200 is located at the signal outlet 112 of the cavity 110. The cross section of the signal transmission member 200 perpendicular to the length direction thereof may be circular, elliptical, polygonal or irregular, and the cross section of the signal transmission member 200 is not particularly limited herein.

The limiting structure 300 is mounted to at least one of the cavity 110 and the cover plate 120. The limiting structure 300 is used for fixing the signal transmission member 200 located in the cavity 110. The limiting structure 300 includes a first limiting member 310 and a second limiting member 320, where the first limiting member 310 and the second limiting member 320 are connected by interference fit. In this way, in the high and low temperature environment, the first stopper 310 and the second stopper 320 expand or contract synchronously, and no looseness occurs between the first stopper 310 and the second stopper 320. At least one of the first limiting member 310 and the second limiting member 320 clamps and fixes the signal transmission member 200, so that the signal transmission member 200 does not loosen in a high-low temperature environment, the position stability of the signal transmission member 200 is improved, the change of the electric parameters of the filter caused by the position movement of the signal transmission member 200 relative to the cavity 110 is avoided, the working stability of the filter is improved, the abnormal sound problem caused by the looseness of the signal transmission member 200 is reduced, the reject ratio is reduced, and the manufacturing cost is saved.

In some embodiments, the number of the limiting structures 300 is more than two, and the more than two limiting structures 300 are spaced apart along the length direction of the signal transmission member 200. The limiting structure 300 carries out a plurality of limiting supports on the signal transmission member 200 in the length direction, so that the signal transmission member 200 is prevented from bending deformation due to too long suspension length.

Optionally, the limiting structure 300 is mounted to the cavity 110. For example, the first limiting member 310 is mounted to the cavity 110, and the second limiting member 320 is connected to the first limiting member 310 through an interference fit. For another example, the second limiting member 320 is mounted on the cavity 110, and the first limiting member 310 is connected to the second limiting member 320 through an interference fit.

Optionally, the limiting structure 300 is mounted to the cover plate 120. For example, the first limiting member 310 is mounted on the cover plate 120, and the second limiting member 320 is connected to the first limiting member 310 through an interference fit. For another example, the second limiting member 320 is mounted on the cover plate 120, and the first limiting member 310 is connected to the second limiting member 320 through an interference fit.

Optionally, the limiting structure 300 is mounted to both the cavity 110 and the cover 120. For example, the first limiting member 310 is installed in the cavity 110, the second limiting member 320 is installed in the cover plate 120, and the first limiting member 310 and the second limiting member 320 are connected by interference fit. For another example, the first limiting member 310 is installed on the cover plate 120, the second limiting member 320 is installed on the cavity 110, and the first limiting member 310 and the second limiting member 320 are connected by interference fit.

In this embodiment, the mounting may be performed by bonding, welding, crimping, clamping, sleeving, interference fit, threaded connection, or the like, or may be performed by abutting, for example, one manner in which the limiting structure 300 is simultaneously mounted on the cavity 110 and the cover plate 120 may be that the first limiting member 310 abuts against the cavity 110, the second limiting member 320 abuts against the cover plate 120, the first limiting member 310 and the second limiting member 320 are abutted between the cavity 110 and the cover plate 120, the first limiting member 310 is not fixedly mounted on the cavity 110, and the second limiting member 320 is not fixedly mounted on the cover plate 120.

It should be noted that, when the limiting structure 300 is mounted on the cavity 110 and/or the cover plate 120, the limiting structure 300 may be located entirely inside the cavity 110, or may partially protrude outside the cavity 110. Optionally, the limiting structure 300 partially protrudes from the outer surface of the cavity 110; alternatively, the limiting structure 300 partially protrudes from the outer surface of the cover plate 120; alternatively, the limiting structure 300 partially protrudes from the outer surface of the cavity 110 and the outer surface of the cover plate 120. Illustratively, the first limiting member 310 is mounted to the cavity 110, and a portion of the first limiting member 310 (e.g., one end of the first limiting member 310) protrudes from the outer surface of the cavity 110; alternatively, the first limiting member 310 is mounted on the cover plate 120, and a portion of the first limiting member 310 (for example, one end of the first limiting member 310) protrudes from the outer surface of the cover plate 120; illustratively, the second limiting member 320 is mounted to the cavity 110, and a portion of the second limiting member 320 (e.g., one end of the second limiting member 320) protrudes from the outer surface of the cavity 110; alternatively, the second limiting member 320 is mounted on the cover plate 120, and a portion of the second limiting member 320 (e.g., one end of the second limiting member 320) protrudes from the outer surface of the cover plate 120.

In some embodiments, the first limiting member 310 may be separately connected to the cavity 110 by using an adhesive, welding, crimping, clamping, sleeving, interference fit, screwing, or the like, which is not limited herein. The first limiting member 310 may be installed at the bottom of the cavity 110, or may be installed at a side portion of the cavity 110, and an installation position of the first limiting member 310 in the cavity 110 is not specifically limited. The second stopper 320 may be connected to the cover plate 120 or may be separated from the cover plate 120.

For example, referring to fig. 4 and 5, the cavity 110 is provided with a mounting groove 113, and the first stopper 310 is mounted in the mounting groove 113. Specifically, the first limiting member 310 is connected to the mounting groove 113 by means of plugging, crimping, screwing, interference fit, or the like. When the first limiting member 310 is mounted in the mounting groove 113 in an interference fit manner, in a high-temperature environment, even if the thermal expansion coefficients of the first limiting member 310 and the cavity 110 made of metal materials are greatly different, the first limiting member 310 cannot prop open the cavity 110 under the limitation of the mounting groove 113; in a low-temperature environment, although the first limiting member 310 is contracted, the first limiting member is still in contact with the wall of the mounting groove 113 without a gap, so that the first limiting member 310 and the signal transmission member 200 are ensured not to generate abnormal sound due to loosening.

In addition, the first limiting piece 310 is installed in the installation groove 113 in an interference fit manner, welding, clamping, bonding or screwing operation is not needed, only the first limiting piece 310 is needed to be pressed in the installation groove 113, the installation operation is simple and convenient, and the structural strength of the cavity 110 and the first limiting piece 310 cannot be damaged.

Optionally, the volume of the first limiting member 310 is larger than the volume of the second limiting member 320, and the first limiting member 310 is mounted at the bottom of the cavity 110. Compare second locating part 320, first locating part 310 is big with the bottom area of contact of cavity 110, and cavity 110 can stabilize and support first locating part 310 that the volume is big, and first locating part 310 can stabilize and support second locating part 320 that is connected with it interference fit and that the volume is less, is favorable to improving the stability and the fastness of limit structure 300 installation.

Of course, in some other embodiments, such as fig. 7, the second limiting member 320 may be mounted to the cavity 110, for example, the second limiting member 320 is mounted in the mounting groove 113 of the cavity 110.

Optionally, the volume of the first limiting member 310 is larger than the volume of the second limiting member 320, the second limiting member 320 is mounted at the bottom of the cavity 110, and the first limiting member 310 is connected with the second limiting member 320 through interference fit. Compared with the first limiting piece 310, the second limiting piece 320 with smaller size needs a small mounting surface, can be mounted in the cavity 110 with smaller bottom area, can be suitable for the cavity 110 with smaller bottom surface, and is also beneficial to reducing the occupied area of the cavity 110.

In some embodiments, the cavity 110 is made of a metal material, and the limiting structure 300 is made of an insulating material, so as to ensure insulation between the signal transmission member 200 and the cavity 110 and the cover plate 120.

In this embodiment, the first limiting member 310 and the second limiting member 320 are in interference fit, so that a very strict tolerance zone is required, and the reliability of the size and the position of the limiting structure 300 is improved, so that the signal transmission member 200 is clamped in the limiting structure 300 in a more accurate positioning manner, and the position of the signal transmission member 200 is convenient to control. Among these, many embodiments of interference fit are possible.

In one embodiment, referring to fig. 4 and 5, the first stopper 310 has a groove 311, and the second stopper 320 is interference-fitted in the groove 311, so that the second stopper 320 is positionally stably fixed and positioned in the groove 311 without loosening, ensuring positional stability of the signal transmission member 200, and electrical parameters of the filter, whether in a high temperature environment or a low temperature environment.

Specifically, the groove 311 can accommodate the end of the second limiting member 320, the end of the second limiting member 320 is mounted in the groove 311 in an interference fit, and the second limiting member 320 does not need to be additionally provided with a structure for interference fit with the groove 311. Of course, in other embodiments, in conjunction with fig. 6, the second limiting member 320 may be provided with a protrusion 321 for interference fit with the recess 311, where the protrusion 321 is embedded in the recess 311 in an interference fit, so that the relative position of the second limiting member 320 and the first limiting member 310 remains stable in the high and low temperature environment, and at this time, the recess 311 may be designed to be smaller to reduce the processing amount of the recess 311.

In another embodiment, the second limiting member 320 has a groove 311, and the first limiting member 310 is mounted in the groove 311 in an interference fit manner, so that the position stability of the limiting structure 300 and the signal transmission member 200 in a high-low temperature environment is realized, and the stability of the electrical parameters of the filter is ensured. At this time, the first limiting portion may be mounted in the groove 311 with the end portion in direct interference fit, or may be provided with the protrusion 321 for interference fit with the groove 311, that is, a specific interference fit manner between the first limiting member 310 and the second limiting member 320 is not limited.

In this embodiment, there are many ways to clamp and fix the signal transmission member 200 by the first limiting member 310 and the second limiting member 320.

For example, the signal transmission member 200 may be clamped and fixed only in the first limiting member 310, and the first limiting member 310 may be provided with a first limiting groove 312 for clamping and fixing the signal transmission member 200; for example, the signal transmission member 200 may be clamped and fixed only to the second limiting member 320, and the second limiting member 320 may be provided with a second limiting groove 322 for clamping and fixing the signal transmission member 200; for another example, the signal transmission member 200 is clamped and fixed by the first limiting member 310 and the second limiting member 320 together, alternatively, the signal transmission member 200 is clamped and fixed to both the first limiting groove 312 of the first limiting member 310 and the second limiting groove 322 of the second limiting member 320. In this way, the limiting structure 300 can clamp and fix the signal transmission member 200 in various modes, and the shape and the size of the signal transmission member 200 and the cavity 110 are not specifically required, so that the limiting structure can be suitable for the cavity 110 and the signal transmission member 200 with different specifications and sizes.

In one embodiment, referring to fig. 2 and 3, the first limiting member 310 has a first limiting groove 312, and the length direction of the first limiting groove 312 is consistent with the length direction of the signal transmission member 200, and the signal transmission member 200 is supported in the first limiting groove 312. The groove walls of the first limiting groove 312 perform a limiting function on the signal transmission member 200, so that the signal transmission member 200 is stably positioned in the first limiting groove 312.

The signal transmission member 200 may be in line contact with the groove wall of the first limiting groove 312 or in surface contact with the groove wall. The signal transmission member 200 may be adhesively bonded, crimped, snapped, welded or interference fit into the first spacing groove 312.

Optionally, the groove wall of the first limiting groove 312 is attached to the outer surface of the signal transmission member 200, so that the contact area between the groove wall of the first limiting groove 312 and the signal transmission member 200 is increased, and the groove wall of the first limiting groove 312 is attached to the outer surface of the signal transmission member 200, so that the first limiting groove 312 limits the signal transmission member 200 in multiple directions, and the limiting effect of the first limiting groove 312 is improved.

For example, referring to fig. 3, the groove walls of the first limiting groove 312 abut against opposite sides of the signal transmission member 200 along the second direction Y, so as to limit the signal transmission member 200 in the second direction Y.

Specifically, the second limiting member 320 has a second limiting groove 322, the length direction of the second limiting groove 322 is consistent with the length direction of the signal transmission member 200, the opening of the first limiting groove 312 and the opening of the second limiting groove 322 are disposed opposite to each other, and the signal transmission member 200 is supported in the second limiting groove 322. In this way, opposite sides of the signal transmission member 200 in a certain direction respectively abut against the groove wall of the first limiting groove 312 and the groove wall of the second limiting groove 322, so as to realize the limiting of the signal transmission member 200 in a certain direction and limit the signal transmission member 200 to move in a certain direction.

For example, in conjunction with fig. 3, in the third direction Z, the groove wall of the first limiting groove 312 abuts against the bottom of the signal transmission member 200, and the groove wall of the second limiting groove 322 abuts against the top of the signal transmission member 200, so that the limiting structure 300 limits the signal transmission member 200 in the third direction Z.

Optionally, the groove wall of the second limiting groove 322 is attached to the outer surface of the signal transmission member 200, so that not only the contact area between the groove wall of the second limiting groove 322 and the signal transmission member 200 is increased, but also the second limiting groove 322 limits the signal transmission member 200 in multiple directions.

Specifically, the first limiting grooves 312 and the second limiting grooves 322 are distributed at intervals along the length direction of the signal transmission member 200, which is not only beneficial to increasing the supporting points of the signal transmission member 200 in the length direction, but also the first limiting grooves 312 and the second limiting grooves 322 are spaced apart and avoid interference, so that the design flexibility of the first limiting grooves 312 and the second limiting grooves 322 is improved. For example, in the cross section perpendicular to the length direction, the first limiting groove 312 can extend in a direction close to the second limiting groove 322, the second limiting groove 322 can extend in a direction close to the first limiting groove 312, the two grooves cannot interfere with each other, the contact area with the signal transmission member 200 can be increased, the signal transmission member 200 is wrapped, and the signal transmission member 200 is limited in the second direction Y and the third direction Z.

In other embodiments, the second limiting member 320 may not be provided with the second limiting groove 322, or the first limiting groove 312 is located in the second limiting member 320, and the first limiting member 310 is not provided with the limiting groove for supporting the signal transmission member 200, so that the limiting and fixing effects on the signal transmission member 200 can be achieved.

In some embodiments, referring to fig. 2 and 3, the signal transmission member 200 has a first step surface 201, where the first step surface 201 is substantially perpendicular to the length direction of the signal transmission member 200, that is, an angle between the first step surface 201 and the length direction is 70 ° to 100 °, and the first step surface 201 abuts against a sidewall of at least one of the first limiting member 310 and the second limiting member 320. The first step surface 201 prevents the signal transmission member 200 from moving in the length direction toward the side wall in contact therewith, and realizes one-side limitation of the signal transmission member 200 in the length direction, that is, one-side limitation of the signal transmission member 200 in the first direction X, thereby further improving the position stability of the signal transmission member 200.

Specifically, the signal transmission member 200 has a second step surface 202, the second step surface 202 is substantially perpendicular to the length direction of the signal transmission member 200, that is, an included angle between the second step surface 202 and the length direction is 70 ° to 100 °, and the first step surface 201 and the second step surface 202 are disposed opposite to each other or are disposed opposite to each other. The second step surface 202 abuts a sidewall of at least one of the first stop 310 and the second stop 320. The first step surface 201 and the second step surface 202 prevent the signal transmission member 200 from moving along any side in the length direction, so that the signal transmission member 200 is limited in the length direction, that is, the signal transmission member 200 is limited in the first direction X, and the position stability of the signal transmission member 200 in the first direction X is further improved.

Referring to fig. 3, the second limiting member 320 is installed on the first limiting member 310 in an interference fit manner, and is fixed in position, and the first step surface 201 and the second step surface 202 respectively abut against two opposite sides of the second limiting member 320 in the length direction, so that the two opposite sides of the second limiting member 320 in the length direction limit the movement of the signal transmission member 200 in the length direction, and the limitation of the signal transmission member 200 in the length direction (the first direction X) is realized.

It will be appreciated that in other embodiments, the first step surface 201 and the second step surface 202 may abut against opposite sides of the first limiting member 310 in the length direction, or the first step surface 201 abuts against the first limiting member 310 and the second limiting member 320 at the same time, or the second step surface 202 abuts against the first limiting member 310 and the second limiting member 320 at the same time, which can improve the position stability of the signal transmission member 200 in the length direction.

Specifically, the signal transmission member 200 includes at least one large diameter section 210 and at least one small diameter section 220 distributed along the length direction, and the outer diameter of the small diameter section 220 is smaller than the outer diameter of the large diameter section 210. When the small diameter section 220 is a first cylinder, the outer diameter of the small diameter section 220 refers to the diameter of the first cylinder. When the small diameter section 220 is not cylindrical, the outer diameter of the small diameter section 220 refers to the diameter of a circumscribed circle of a cross section perpendicular to the length direction. Similarly, when the large diameter section 210 is not cylindrical, the outer diameter of the large diameter section 210 is the diameter of a circumscribed circle having a cross section perpendicular to the longitudinal direction.

Referring to fig. 3, two ends of the small diameter section 220 are respectively connected with one large diameter section 210, and a first step surface 201 and a second step surface 202 are respectively formed at the connection position of the two ends of the small diameter section 220 and the large diameter section 210. The first limiting member 310 is provided with two first limiting grooves 312 in the length direction, the first limiting grooves 312 are used for supporting the large-diameter section 210, and a groove 311 is arranged between the two first limiting grooves 312. The end of the second stopper 320 is interference-fitted in the groove 311. The end of the second limiting member 320 has a second limiting groove 322 penetrating in the length direction. The second limiting groove 322 of the second limiting member 320 clamps the fixed small-diameter section 220, and two opposite sides of the second limiting member 320 in the length direction respectively abut against the first step surface 201 and the second step surface 202. In this way, the signal transmission member 200 is limited by the opposite side walls of the second limiting member 320 in the length direction (the first direction X), limited by the bottoms of the first limiting groove 312 and the second limiting groove 322 in the third direction Z, and limited by the side walls of the first limiting groove 312 and the second limiting groove 322 in the second direction Y, i.e. the signal transmission member 200 is limited in all directions, and the position accuracy is high.

In this embodiment, the first stopper 310 and the second stopper 320 may be block-shaped or sheet-shaped, which is not limited herein.

The foregoing description of the preferred embodiments of the utility model is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the utility model.

Claims (10)

1. A filter, characterized by: the filter includes:

a cavity;

the cover plate covers the cavity;

a signal transmission member at least partially disposed in the cavity;

the limiting structure is arranged in the cavity and/or the cover plate, and comprises a first limiting part and a second limiting part, wherein the first limiting part is connected with the second limiting part through interference fit, and the first limiting part and/or the second limiting part is clamped and fixed on the signal transmission part.

2. The filter according to claim 1, wherein: one of the first limiting piece and the second limiting piece is provided with a groove, and the other one of the first limiting piece and the second limiting piece is installed in the groove in an interference fit mode.

3. The filter according to claim 2, wherein: the first limiting piece is provided with the groove, and the end part of the second limiting piece is installed in the groove in an interference fit manner;

or, the second limiting piece is provided with the groove, and the end part of the first limiting piece is installed in the groove in an interference fit mode.

4. The filter according to claim 1, wherein: one of the first limiting piece and the second limiting piece is provided with a first limiting groove, the length direction of the first limiting groove is consistent with the length direction of the signal transmission piece, and the signal transmission piece is supported in the first limiting groove.

5. The filter of claim 4, wherein: the other one of the first limiting piece and the second limiting piece is provided with a second limiting groove, the length direction of the second limiting groove is consistent with the length direction of the signal transmission piece, the opening of the first limiting groove and the opening of the second limiting groove are oppositely arranged, and the signal transmission piece is supported in the second limiting groove.

6. The filter of claim 5, wherein: the first limit grooves and the second limit grooves are distributed at intervals along the length direction of the signal transmission piece.

7. The filter of claim 4, wherein: the cell wall of the first limit groove is attached to the outer surface of the signal transmission piece.

8. The filter according to claim 1, wherein: the signal transmission piece is provided with a first step surface, the first step surface is approximately perpendicular to the length direction of the signal transmission piece, and the first step surface is abutted against the side wall of the first limiting piece and/or the side wall of the second limiting piece.

9. The filter of claim 8, wherein: the signal transmission piece is provided with a second step surface, the second step surface is approximately perpendicular to the length direction of the signal transmission piece, and the first step surface and the second step surface are oppositely arranged or oppositely arranged.

10. A filter according to any one of claims 1 to 9, characterized in that: the volume of the first limiting piece is larger than that of the second limiting piece;

the first limiting piece is arranged at the bottom of the cavity, or the second limiting piece is arranged at the bottom of the cavity.