CN102287437A - Screw for fixing resonant bar, cavity filter and communication equipment - Google Patents

Abstract

The invention discloses a screw for fixing a resonant bar, a filter adopting the screw and communication equipment adopting the cavity filter; the screw is provided with a bar part which is at least locally provided with a thread; one end of the bar part is a screw head; a transition area is formed between the screw head and the bar part; a circular groove is arranged around the transition area with the bar part as the center; the transition area is arranged in the groove; the depth of the groove is more than the height of the transition area; and when the resonant bar is fixed, the top surface of the groove presses the bottom of the resonant bar, so that the resonant bar is fixed. The cavity filter adopts the screw, the transition area of the screw is arranged in the groove, so that the transition area does not press the bottom surface of the resonant bar, the resonant bar can be very well fixed under the condition that the screw has equal stress, and the phenomena that the resonant bar deforms and the performance of the filter is affected due to the transition area do not exist. The communication equipment adopts the cavity filter, so that the filtering performance can be very well realized.

Description

Screws for fixing resonant rods, cavity filters and communication equipment

technical field

The invention relates to a communication device, in particular to a cavity filter and a communication device using the cavity filter.

Background technique

As an important communication device, cavity filter plays an irreplaceable role in the field of radio transmission.

A cavity filter usually includes a cavity and a resonance tube, the cavity is provided with multiple cavities, and each cavity accommodates a resonance tube. In order to ensure that the cavity filter can effectively filter out noise and interference signals, the connection between the resonant tube and the cavity in the cavity filter must be tightly structured. At present, there is a through hole at the bottom of the resonant tube in the cavity filter, and then the fixing screw The resonance tube is fixed on the supporting seat of the cavity through the through hole. As shown in Figure 1, the fixing screw is formed by stamping equipment, including the screw head 2 and the screw rod 3. In order to avoid the stress concentration on the joint between the screw head 2 and the screw rod 3 and cause the screw to break, the screw head and the screw rod There will be a transition zone 1 at the junction, and the transition zone is either a rounded corner or a tapered surface, which can withstand a large enough stress to prevent the screw from breaking, and is a good way to solve the stress concentration.

However, during the research and practice of the prior art, the inventors of the present invention have found that when the screw fixes the resonant tube and the cavity, as shown in Figure 2, since the transition zone on the fixing screw protrudes beyond the screw rod , therefore, when the screw is tightened, as shown in Figure 3, the transition zone protruding from the screw rod will inevitably press the bottom surface of the resonant tube it contacts, causing the bottom surface of the resonant tube to be deformed by force, and the part away from the through hole on the bottom surface of the resonant tube It will be lifted upwards, causing a gap in the connection between the bottom surface of the resonant tube and the cavity support seat, which will affect the indicators of the cavity filter. In addition, the deformation of the resonant tube itself will also affect the filtering performance and other quality indicators. Therefore, how to avoid the influence of the transition area protruding from the screw rod on the performance index of the filter when fixing the resonant rod is a problem that cannot be ignored.

Contents of the invention

In order to solve the problems caused by the transition zone on the fixing screw of the resonating rod, the present invention provides a screw for fixing the resonating rod and a filter and communication equipment using the screw.

A screw for fixing a resonant rod has a shank with threads at least partially, one end of the shank is a screw head, and a transition zone is formed between the screw head and the shank, and the transition zone is surrounded by the There is an annular groove at the center of the rod, the transition zone is sunk in the groove, the depth of the groove is greater than the height of the transition zone, and when the resonant rod is fixed, the top of the groove faces the bottom of the resonant rod Apply pressure to secure the resonant rod.

For the above-mentioned screw for fixing the resonant rod, the transition zone is an arc transition, and the height of the transition zone is: the distance from the free end of the rod to the position where the arc starts to the direction of the head of the screw to the bottom of the groove , the depth of the groove is 0.2-1.0 mm.

As for the screw for fixing the resonant rod, preferably, the depth of the groove is 0.5 mm.

As for the screw for fixing the resonant rod, the free end of the screw has a conical tip.

A cavity filter, comprising a cavity, a resonant tube and screws, the cavity is provided with a support seat, the bottom surface of the resonant tube is provided with a through hole, and the screw passes through the through hole to fix the resonant tube in the cavity On the support seat, the screw has a shank with at least part of the thread, one end of the shank is the screw head, and there is a transition zone between the screw head and the shank, and the transition zone is surrounded by the There is an annular groove at the center of the rod, and the transition zone is sunk in the groove. The depth of the groove is greater than the height of the transition zone. When fixing the resonance rod, the top of the groove is applied to the bottom of the resonance rod. Pressure secures the resonant rod.

In the above-mentioned cavity filter, the transition area is an arc transition, and the height of the transition area is: the distance from the free end of the rod part to the direction of the screw head to form an arc to the bottom of the groove.

In the above cavity filter, the depth of the groove is the distance from the top surface of the groove to the bottom of the groove, and the depth of the groove is 0.2-1.0 mm.

In the above cavity filter, preferably, the depth of the groove is 0.5 mm.

A communication device, the communication device includes the above-mentioned cavity filter, and the communication device is a duplexer, a combiner or a tower top amplifier.

The screw for fixing the resonant rod provided by the present invention has an annular groove around the transition area of the screw with the rod as the center, so that the transition area is sunk in the groove, so that when the screw provided by the present invention is used to fix the resonant rod When, the transition zone of the screw can be avoided from contacting the bottom surface of the resonant rod, thereby avoiding the problem that the transition zone compresses the bottom surface of the resonant rod and causes its deformation. In the cavity filter provided by the present invention, the above-mentioned screw for fixing the resonant rod is used, and the transition area of the screw is sunk in the groove, so that the transition area no longer presses the bottom surface of the resonant rod. Under the condition that the screw has the same stress, it can be well The resonant rod is fixed, so that the deformation of the resonant rod will not affect the performance index of the filter due to the existence of the transition zone.

The communication device of the present invention uses the above-mentioned cavity filter, and the resonant rod in the cavity filter is closely connected with the supporting seat without gap, so it has good filtering performance.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those skilled in the art, other drawings can also be obtained based on these drawings without creative effort.

Fig. 1 is the three-dimensional structural view of the screw used for fixing the resonance rod in the prior art;

Fig. 2 is a schematic diagram of a cavity filter equipped with screws for fixing a resonant rod in the prior art;

Fig. 3 is a partial enlarged view of A in Fig. 2 .

Fig. 4 is a three-dimensional structure diagram of a screw for fixing a resonant rod provided in Embodiment 1 of the present invention;

Fig. 5 is a cross-sectional view of a screw for fixing a resonant rod provided in Embodiment 1 of the present invention;

FIG. 6 is a cross-sectional view of a cavity filter provided by Embodiment 2 of the present invention;

FIG. 7 is a partial enlarged view of B in FIG. 6 .

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Embodiment 1, as shown in Figure 4 and Figure 5, a screw for fixing a resonant rod has a rod part 23 with at least a part of thread, one end of the rod part is a screw head 21, and at the screw head 21 There is a transition area 22 between the shaft portion 23 and the transition area 22. There is an annular groove 24 around the transition area 22 with the shaft portion 23 as the center. The transition area 22 is sunk in the groove 24, and the depth of the groove is greater than The height of the transition zone is such that when the resonant rod is fixed, the groove top surface 25 exerts pressure on the bottom of the resonant rod to fix the resonant rod. The screw head 21 may be round, square or other shapes, the shape of the screw head is not enough to limit the present invention.

The end of the shank 23 of the screw in contact with the bottom surface of the screw head is a fixed end, and the end far away from the screw head is a free end. There are threads on the screw shank, and the distribution of the threads can be locally distributed on the screw shank, or can cover the entire screw shank, so as to increase the fixation of the screw.

In order to introduce the embodiment of the present invention more clearly, the head 21 of the screw is divided into two surfaces within the limits shown in the drawings provided by the present invention, and the top surface of the head 21 of the screw has a The bottom surface of the head 21 of the screw is in contact with the shank of the screw. In order to reduce the stress concentration on the joint position of the head 21 of the screw and the shank 23 of the screw, the head 21 of the screw and the shank of the screw 23 are combined The transition zone 22 is processed at the top position, and the transition zone 22 is formed during screw processing. The transition zone can be a rounded corner or a conical surface. As a preferred embodiment, the transition zone 22 is arc-shaped transition, the height h of the transition zone 22, as shown in FIG. Ensure that there is a sufficient stress between the screw head 21 and the screw shank 23 to prevent the screw from breaking at the joint.

The groove 24 on the screw is formed on the screw head 21, centered on the shank 23 of the screw, and recessed inwardly on the bottom surface of the head of the screw, so as to ensure that the transition zone 22 is completely sunk in the groove 24. It can be understood that, When the bottom surface of the head of the screw is inwardly recessed to form a groove, the part of the bottom surface of the head that is not inwardly recessed is the groove top surface 25, and the groove top surface 25 is in contact with the bottom of the resonant rod when the resonant rod is fixed. , to apply pressure to the bottom of the resonant rod, thereby fixing the resonant rod, completely avoiding the contact between the transition zone and the bottom of the resonant rod. It can also be understood that, as shown in Figure 7, the depth H of the groove is the distance from the top surface 25 of the groove to the bottom of the groove. As a preferred embodiment, the depth H of the groove is selected from 0.2 mm to 1.0 mm. between. And when the depth H of the groove is 0.5 mm, the transition zone can be completely trapped in the groove, and the stress effect of the screw is also the best. It is obvious that the groove depth H of the screw provided by the embodiment of the present invention is not less than the height of the transition zone h, so as to ensure that the transition zone is completely immersed in the groove, and avoid the transition zone from contacting the bottom of the resonance rod when fixing the resonance rod.

As an improvement, the free end of the screw rod provided by the embodiment of the present invention has a conical tip, which is convenient for the screw to pass through the through hole of the resonant rod, and at the same time can increase the pressure of the free end of the screw rod, making it easier for the screw to The resonant rod is locked on the supporting base of the cavity.

The screw used to fix the resonant rod provided by the embodiment of the present invention is provided with an annular groove around the transition area of the screw and centered on the rod, so that the transition area is sunk in the groove, and the depth of the groove is H It is greater than the height h of the transition zone, so when the screw provided by the present invention is used to fix the resonant rod, the top of the groove exerts pressure on the bottom of the resonant rod, which can avoid the contact between the transition zone of the screw and the bottom surface of the resonant rod, thereby avoiding the pressure of the transition zone The underside of the resonating rod causes problems with its deformation.

Embodiment 2. A cavity filter provided in this embodiment, as shown in FIG. 6 and FIG. 7, is a sectional view and a partial enlarged view of the cavity filter provided in this embodiment, including a cavity 31 and a resonant tube 32 and screw 33, the cavity is provided with a support seat 34, the bottom surface of the resonant tube 32 is provided with a through hole, and the screw passes through the through hole to fix the resonant tube 32 on the support seat 34 in the cavity 31, so The screw 33 has a shank with thread at least partially, one end of the shank is a screw head, and a transition zone is formed between the screw head and the shank, and there is a center around the transition zone with the shank as the center. An annular groove, the transition zone is sunk in the groove, the depth of the groove is greater than the height of the transition zone, and when the resonant rod is fixed, the top of the groove applies pressure to the bottom of the resonant rod to fix the resonant rod.

The cavity filter provided in this embodiment uses the screw described in Embodiment 1, the transition area of the screw is sunk in the groove, and pressure is applied to the bottom of the resonating rod through the top of the groove, so that the transition area no longer presses the bottom surface of the resonating rod , under the condition of ensuring that the screws have the same stress, the resonant rod can be well fixed without affecting the performance index of the filter due to the deformation of the resonant rod due to the existence of the transition zone.

An embodiment of the present invention also provides a communication device, the communication device includes the above-mentioned cavity filter, and the communication device is a duplexer, a combiner or a tower mounted amplifier. The cavity filter is the basic structural component of the communication device in this embodiment. For example, the duplexer is composed of two cavity filters at the receiving end and the transmitting end of the duplexer to realize the filtering function of sending and receiving signals; and The combiner is realized by combining two cavity filters to form a combined circuit. For the tower top amplifier, the cavity filter is also used as the basic structural component, and no examples are given here.

The communication device in the embodiment of the present invention uses the above-mentioned cavity filter, and the resonant rod in the cavity filter is closely connected with the supporting seat without gap, so that the communication device has good filtering performance.

In this paper, specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; meanwhile, for those of ordinary skill in the art, according to the present invention Thoughts, there will be changes in the specific implementation and application scope. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims (10)

1. A screw for fixing a resonant rod, characterized in that: there is at least a partially threaded rod, one end of the rod is a screw head, and a transition zone is between the screw head and the rod, so There is an annular groove around the transition zone with the rod as the center, the transition zone is sunk in the groove, the depth of the groove is greater than the height of the transition zone, and when the resonant rod is fixed, the groove The top presses against the bottom of the resonating rod to secure the resonating rod. 2. The screw for fixing the resonant rod according to claim 1, characterized in that: the transition zone is an arc transition, and the height of the transition zone is: from the free end of the rod to the direction of the screw head The distance from the position where the arc is generated to the bottom of the groove. 3. The screw for fixing a resonant rod according to claim 1 or 2, wherein the depth of the groove is the distance from the top surface of the groove to the bottom of the groove, and the depth of the groove is 0.2-1.0 mm. 4. The screw for fixing the resonant rod according to claim 3, characterized in that: the depth of the groove is 0.5 mm. 5. The screw for fixing a resonant rod according to claim 3, characterized in that: the free end of the shank of the screw has a conical tip. 6. A cavity filter, characterized in that: it comprises a cavity, a resonant tube and a screw, the cavity is provided with a support seat, the bottom surface of the resonant tube is provided with a through hole, and the screw passes through the through hole to The resonant tube is fixed on the support seat in the cavity, the screw has a shank with thread at least partially, one end of the shank is the screw head, and there is a transition zone between the screw head and the shank, and the transition There is an annular groove centered on the rod around the zone, the transition zone is sunk in the groove, the depth of the groove is greater than the height of the transition zone, and when the resonant rod is fixed, the top surface of the groove Apply pressure to the bottom of the resonating rod to secure the resonating rod. 7. The cavity filter according to claim 6, characterized in that: the transition zone is an arc transition, and the height of the transition zone is: from the free end of the rod to the direction of the screw head The distance from the position of the arc to the bottom of the groove. 8. The cavity filter according to claim 6 or 7, wherein the depth of the groove is the distance from the top surface of the groove to the bottom of the groove, and the depth of the groove is 0.2-1.0 mm. 9. The cavity filter according to claim 8, wherein the depth of the groove is 0.5 mm. 10. A communication device, characterized in that the communication device comprises the cavity filter according to any one of claims 6-9, and the communication device is a duplexer, a combiner or a tower mounted amplifier .

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