A filter

Abstract

A filter includes a cavity, one side of which is open, and a cover plate is installed on the open side. The cavity includes a bottom wall and four side walls extending upward from the bottom wall, and the side wall is provided with a mounting groove downward at the opening. A mounting post is fixed in the mounting groove, and the mounting post includes a first mounting post and a second mounting post below the first mounting post for guiding and positioning. The first mounting post is provided with a grounding ring, and the mounting post is also provided with a through hole for the cable to pass through. The mounting post is radially interference fit with the mounting groove, and the mounting post is axially interference fit with the cover plate. The present invention provides a grounding ring at the top of the mounting post, so that the grounding ring and the cover plate are embedded in each other during the assembly process to achieve axial shielding. At the same time, a stepped fit is adopted at the joint between the mounting post and the mounting groove, achieving full radial interference shielding while facilitating riveting.

Description

Technical Field

[0001] The present invention relates to the field of communication technology, and in particular to a filter. Technical Background

[0002] As a communication device for frequency selection and suppression of remote harmonics, the filter is one of the indispensable components in wireless communication systems.

[0003] The mounting post of existing filters is a cylindrical column with a constant outer diameter. The radius and length of the post match the width and depth of the mounting slot, which can easily create a gap between the post and the slot. The top of the existing post is flat. During installation, the top of the post should theoretically be flattened with the cover plate as the reference plane. However, in practice, the post may not be pressed into place or may even sag during the riveting process. If the post is not pressed into place, the strong strength of the post can cause the cover plate to bulge, creating a leak point. If the post sags, it can create a gap with the cover plate, also creating a leak point, seriously affecting product performance.

[0004] In view of this, it is necessary to design a filter to solve the above problems. Summary of the Invention

[0005] The purpose of the present invention is to provide a filter in order to overcome the problem that leakage is easily caused during the installation process of the installation column in the above technical background.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a filter comprising a cavity, one side of the cavity being open, a cover plate being mounted on the open side. The cavity comprises a bottom wall and four side walls extending upward from the bottom wall, each side wall having a mounting slot formed downwardly from the opening. A resonant structure is disposed within the cavity and comprises a support base extending inwardly from the bottom wall of the cavity, and a resonant rod mounted on the support base. A tuning screw is secured to the cover plate via a nut and cooperates with the resonant structure to adjust the frequency. A tap has one end screwed to the support base and the other end welded to a cable for signal transmission. A mounting post is secured within the mounting slot and comprises a first mounting post and a second mounting post below the first mounting post for guiding and positioning. The first mounting post is provided with a grounding ring and a through-hole for the cable to pass through. The mounting post forms an interference fit with the mounting slot in the radial direction and with the cover plate in the axial direction.

[0007] Preferably, the support base includes a first support base and a second support base connected to the first support base, the first support base and the second support base are distributed in a stepped manner, the resonant rod is installed on the first support base, and the tap is installed on the second support base.

[0008] Preferably, the cable is a coaxial cable, which comprises a wire core, an insulating layer, a metal layer and a protective layer from the inside to the outside. The wire core is welded to the tap, and the metal layer is welded to the mounting post.

[0009] Preferably, the mounting groove includes a groove bottom wall parallel to the cavity bottom wall and two groove side walls extending upward from the groove bottom wall, the two groove side walls are provided with mutually symmetrical arc grooves, and the groove bottom wall is provided with a countersunk groove.

[0010] Preferably, the two arc-shaped grooves are arranged to form a first mounting hole and a second mounting hole, the second mounting hole is located below the first mounting hole, the radius of the first mounting hole is larger than the radius of the second mounting hole, and the depth of the first mounting hole is equal to the depth of the second mounting hole.

[0011] Preferably, the depth of the first mounting hole is less than the length of the first mounting column, and the depth of the second mounting hole is less than the length of the second mounting column.

[0012] Preferably, the first mounting post and the first mounting hole have an interference fit, the second mounting post and the first mounting hole have a clearance fit, and the second mounting post and the second mounting hole have an interference fit.

[0013] Preferably, the bottom of the mounting post is provided with a chamfer, and the bottom of the mounting post extends into the sink.

[0014] Preferably, the top of the grounding ring extends out of the mounting slot, and the top of the grounding ring is provided with a cut corner.

[0015] Preferably, the mounting column is provided with an elastic groove 1 which runs across the first mounting column and the second mounting column, the width of the elastic groove 1 is smaller than the width of the arc-shaped groove, the opening of the elastic groove 1 is closed by the arc-shaped groove, and the bottom of the second mounting column is provided with an elastic groove 2.

[0016] The present invention provides a grounding ring at the top of the mounting post. Since the grounding ring is relatively narrow, it forms a knife-edge effect when mated with the cover plate, and can be directly embedded in the cover plate. At the same time, due to the poor strength of the grounding ring, a portion of it will undergo plastic deformation after being subjected to the pressure of the cover plate, so that it fits tightly with the cover plate without causing the cover plate to bulge. A stepped interference fit is adopted for radial fit, that is, when the second mounting post first enters the first mounting hole of the mounting groove, this fit is a clearance fit, so assembly is relatively convenient, and this process also achieves a guiding and positioning function. When the second mounting post enters the second mounting hole of the mounting groove, the first mounting post follows closely and enters the first mounting hole of the mounting groove. In this process, the mounting post and each part of the mounting groove are all interference fit, and radial full interference fit shielding is achieved from the surface. Since the depth of the second mounting hole is close to half the length of the mounting post, the riveting stroke is approximately half the total length, and the riveting positioning and process are relatively simple. The bottom wall of the mounting slot is recessed, while the bottom of the mounting post is chamfered, allowing the post to extend into the recessed slot. This prevents a gap between the post and the bottom of the slot, which may occur if the post is too short during production, and thus achieves better shielding. This structure can also be used in other applications with similar shielding requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 An exploded view of a first embodiment of the present invention;

[0018] Figure 2 This is a schematic structural diagram of a mounting post according to a first embodiment of the present invention;

[0019] Figure 3 A cross-sectional view of a first embodiment of the present invention;

[0020] Figure 4 This is an enlarged view of the cross-sectional view of the first embodiment of the present invention at the joint between the mounting post and the mounting groove;

[0021] Figure 5 This is a schematic structural diagram of a mounting post according to a second embodiment of the present invention;

[0022] Figure 6 This is a top view of the second embodiment of the present invention after removing the cover plate;

[0023] Figure 7 This is a schematic structural diagram of a mounting post according to a third embodiment of the present invention;

[0024] Figure 8 It is a cross-sectional view of the coaxial cable in the present invention. DETAILED DESCRIPTION

[0025] The following will be combined with the accompanying drawings in the embodiments of the present invention to provide a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] like Figures 1 to 4 As shown, a filter 100 includes a cavity 1, one side of which is open, and a cover 2 is installed on the open side. The cavity 1 includes a bottom wall and four side walls extending upward from the bottom wall. One of the side walls is provided with a mounting groove 11 downward at the opening for accommodating a mounting post 5. A resonant structure is provided in the cavity 1, which includes a support seat 8 extending inward from the bottom of the cavity 1 and a resonant rod 9 installed on the support seat 8. A tuning screw 3 is locked on the cover 2 by a nut 4. The tuning screw 3 cooperates with the resonant structure to adjust the signal frequency. A tap 10 is also installed in the cavity 1 for transmitting signals. One end of the tap 10 is mounted on the support seat 8 by a screw 7, and the other end is welded to the cable 6. The support base 8 includes a first support base 81 and a second support base 82 connected to the first support base 81 . The first support base 81 and the second support base 82 are distributed in a stepped manner. The resonant rod 9 is installed on the first support base 81 , and the tap 10 is installed on the second support base 82 .

[0027] The mounting post 5 is stepped and includes a first mounting post 51 and a second mounting post 52 located below the first mounting post 51 for guiding and positioning. The top of the first mounting post 51 is provided with a grounding ring 511 with a cut corner, and the bottom of the second mounting post 52 is provided with a chamfer. The mounting post 5 is also provided with a through hole 53 for passing the cable 6, which is a coaxial cable. Figure 8 As shown, the cable 6 comprises a core 61 , an insulating layer 62 , a metal layer 63 and a protective layer 64 from the inside to the outside. The core 61 is welded to the tap 10 , and the metal layer 63 is welded to the mounting post 5 .

[0028] The mounting groove 11 includes a bottom wall 113 parallel to the bottom wall of the cavity 1 and two side walls 114 perpendicular to the bottom wall of the cavity 1. The two side walls 114 are provided with mutually symmetrical arcuate grooves 1141. The bottom wall 113 is provided with a recessed groove 1131. The arcuate groove 1141 encloses a first mounting hole 111 and a second mounting hole 112 located below the first mounting hole 111. The radius of the first mounting hole 111 is greater than the radius of the second mounting hole 112, and the depth of the first mounting hole 111 is equal to the depth of the second mounting hole 112. The length of the first mounting post 51 of the mounting post 5 is greater than the depth of the first mounting hole 111, and the length of the second mounting post 52 is greater than the depth of the second mounting hole 112. The radii of the first mounting post 51 and the second mounting post 52 are respectively greater than the radii of the first mounting hole 111 and the second mounting hole 112.

[0029] During the assembly process, when the second mounting post 52 first enters the first mounting hole 111, the fit between the second mounting post 52 and the first mounting hole 111 is a clearance fit, making assembly more convenient. This process also guides and positions the mounting post 5. When the second mounting post 52 enters the second mounting hole 112, the first mounting post 51 immediately enters the first mounting hole 111. During this process, the mounting post 5 and the mounting slot 11 have a radial interference fit at all mutually mating positions. Continue applying force to press the mounting post 5 downward until the stepped connection between the first mounting post 51 and the second mounting post 52 mates with the stepped connection between the first mounting hole 111 and the second mounting hole 112 of the mounting slot 11. At this point, the bottom of the mounting post 5 extends into the recessed groove 1131, achieving shielding and preventing leakage caused by the mounting post 5 being too short due to processing errors and the bottom not being pressed into place. When installed in mounting slot 11, the grounding ring 511 of the mounting post 5 extends approximately 0.1 mm beyond the mounting slot 11, indicating an axial interference fit between the cover plate 2 and the mounting post 5. After the cover plate 2 is installed, the mounting post 5 is subjected to force that presses downward at the stepped junction between the first mounting hole 111 and the second mounting hole 112. The metal on the slot sidewall 114 at the second mounting hole 112 shifts downward, forming an accumulation on the slot bottom 113. This accumulation of metal prevents the mounting post 5 from reaching the bottom. The provision of a recessed groove 1131 in the slot bottom 113 addresses this metal accumulation, preventing signal leakage and achieving better shielding. Furthermore, since the top of the mounting post 5 is a grounding ring 511 with a cut corner and a narrow width, it forms a knife-edge effect when mated with the cover plate 2. A portion of the grounding ring 511 can be directly embedded in the cover plate 2. At the same time, due to its poor strength, a portion of the grounding ring 511 will be plastically deformed by the pressure of the cover plate 2, so that the grounding ring 511 fits tightly against the cover plate 2 without causing the cover plate 2 to bulge.

[0030] like Figures 5 and 6As shown, the second embodiment of the mounting post 5b of the present invention comprises an elastic groove 1 54b extending transversely from the first mounting post 51b to the second mounting post 52b. The width of the elastic groove 1 54b is smaller than the width of the arcuate groove 1141, and the opening of the elastic groove 1 54b is enclosed by the arcuate groove 1141. The bottom of the second mounting post 52b comprises an elastic groove 2 55b. Due to the structure of the elastic groove 1 54b and the elastic groove 2 55b, the mounting post 5b can undergo a certain elastic deformation, reducing the pressure during riveting during interference fit installation and enhancing shielding. The grounding ring 511b is a two-section, separate arc-shaped metal structure with a chamfered top located at the top of the mounting post 5b. The grounding ring 511b undergoes plastic deformation under pressure from the cover plate 2, ensuring a tight fit between the grounding ring 511b and the cover plate 2 without causing the cover plate 2 to bulge.

[0031] like Figure 7 This is the third embodiment of the mounting post 5c of the present invention. This mounting post 5c includes a first mounting post 51c and a second mounting post 52c. It also has a through-hole 53c for cable passage. The plane of the sidewall of the cavity 1 with the mounting slot 11 is assumed to be a reference plane. The mounting post 5c is provided with two outer walls parallel to this reference plane, defined as planar sidewalls 56c. Of course, curved walls can also be used in place of the planar sidewalls 56c in actual production. The use of planar sidewalls 56c in this solution saves space. Furthermore, during installation, metal debris generated by friction between the mounting post 5c and the mounting slot 11 is easily discharged from the planar sidewalls 56c. The grounding ring 511c at the top of the mounting post 5c is strip-shaped with a chamfered top.

[0032] Of course, the above-mentioned mounting columns are only some embodiments of the present invention. The grounding ring 511 of the mounting column 5 is not limited to the above-mentioned structures. The cross-sectional size of the grounding ring 511 is not greater than the cross-sectional size of the first mounting column 51 .

[0033] The filter of the present invention incorporates a grounding ring 511 at the top of the mounting post 5, allowing the grounding ring 511 to interlock with the cover plate 2 during assembly, achieving axial interference shielding. A stepped fit between the mounting post 5 and the mounting slot 11 achieves full radial interference shielding while facilitating press riveting. Because the depth of the second mounting hole 112 is approximately half the length of the mounting post 5, the press riveting stroke is approximately half the total length, making the press riveting positioning and process relatively simple.

[0034] The above examples are merely illustrative of the present invention and do not limit the scope of protection of the present invention. Any design that is identical or similar to the present invention falls within the scope of protection of the present invention.

Claims

1. A filter comprising: The cavity has one side that is open and a cover plate installed on the open side. The cavity includes a bottom wall and four side walls extending upward from the bottom wall. The side walls are provided with a mounting groove downward at the opening. The resonant structure is arranged in the cavity, comprising a support seat extending inward from the bottom wall of the cavity, and a resonant rod mounted on the support seat, The tuning screw is locked on the cover plate by a nut and adjusts the frequency in conjunction with the resonant structure. The tap has one end mounted on the support base by screws and the other end welded to the cable to transmit the signal. It is characterized in that: the mounting column is fixed in the mounting groove, the mounting column includes a first mounting column and a second mounting column below the first mounting column for guiding and positioning, the first mounting column is provided with a grounding ring, and the mounting column is also provided with a through hole for the cable to pass through, the mounting column is interference fit with the mounting groove in the radial direction, and the mounting column is interference fit with the cover plate in the axial direction.

2. The filter according to claim 1, characterized in that: The support base includes a first support base and a second support base connected to the first support base. The first support base and the second support base are distributed in a stepped manner. The resonant rod is installed on the first support base, and the tap is installed on the second support base.

3. The filter according to claim 1, characterized in that: The cable is a coaxial cable, which comprises a wire core, an insulating layer, a metal layer and a protective layer from the inside to the outside. The wire core is welded to the tap, and the metal layer is welded to the mounting post.

4. The filter according to claim 1, wherein: The mounting groove includes a groove bottom wall parallel to the cavity bottom wall and two groove side walls extending upward from the groove bottom wall. The two groove side walls are provided with mutually symmetrical arc grooves, and the groove bottom wall is provided with a sunken groove.

5. The filter according to claim 4, characterized in that: The two arc-shaped grooves are arranged to form a first mounting hole and a second mounting hole. The second mounting hole is located below the first mounting hole. The radius of the first mounting hole is greater than the radius of the second mounting hole. The depth of the first mounting hole is equal to the depth of the second mounting hole.

6. The filter according to claim 5, characterized in that: The depth of the first mounting hole is less than the length of the first mounting post, and the depth of the second mounting hole is less than the length of the second mounting post.

7. The filter according to claim 6, characterized in that: The first mounting post and the first mounting hole are in interference fit, the second mounting post and the first mounting hole are in clearance fit, and the second mounting post and the second mounting hole are in interference fit.

8. The filter according to claim 7, characterized in that: The bottom of the installation column is provided with a chamfer, and the bottom of the installation column extends into the sink.

9. The filter according to claim 8, characterized in that: The top of the grounding ring extends out of the mounting slot, and the top of the grounding ring is provided with a cut corner.

10. The filter according to claim 4, characterized in that: The mounting post is provided with an elastic groove 1 which runs across the first mounting post and the second mounting post. The width of the elastic groove 1 is smaller than the width of the arc-shaped groove. The opening of the elastic groove 1 is closed by the arc-shaped groove. The bottom of the second mounting post is provided with an elastic groove 2.

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