Tuning structure and filter

Abstract

The invention provides a tuning structure, which belongs to the technical field of communication equipment, and is characterized in that a clamping sleeve piece is additionally arranged between a tuning cover plate and a tuning screw rod, a flange at one end of the clamping sleeve piece is provided with a split groove, so that the end part of the clamping sleeve piece has elasticity, and a clamping bulge has an inclined surface and is matched with a horn mouth of the tuning cover plate; the flange of the clamping sleeve piece protrudes inwards to form the enclasping ring used for enclasping the tuning screw, the outer nut and the clamping sleeve piece are matched with each other to provide locking force, so that the flange of the clamping sleeve piece is elastically shrunk, the tuning screw is enclasped, meanwhile, the tuning screw does not generate metal chippings, and the working stability of the filter is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of communication equipment manufacturing, in particular to a tuning structure in a filter, wherein the frequency is adjusted by adjusting the screwing depth of a tuning screw. Background Art

[0002] The most common adjustment mechanism of the filter is the screw adjustment mechanism, which locks the screw through the interfitting threads, that is, adding threaded holes on the tuning cover, screwing the nut on the screw, and then screwing the screw to the tuning cover. The nut is located above the tuning cover, and the nut is adjusted. The locking of the nut generates a force that makes the thread of the screw and the groove of the tuning cover fit tightly with each other, thereby tightening the screw.

[0003] In the above scheme, during the process of tightening and loosening the screw, due to the large force between the matching teeth, the sharp edges of the teeth rub and cut against each other, which easily produces metal debris. The metal debris falls into the filter cavity and affects the filtering effect. In addition, the teeth on the screw and the teeth on the tuning cover are small bevels. Due to the limitation of processing accuracy, it is difficult to ensure that the spiral bevels along the teeth can contact and lock with each other. It is very likely that a limited number of teeth will be pressed against each other, and the remaining teeth will be suspended or have gaps. The strength of the limited number of teeth is limited. Once the stressed teeth are deformed, the locked screw will easily become loose, thereby affecting the filtering effect of the filter.

[0004] The Chinese utility model patent (CN 209691917 U) adopts the method of opening a hole in the cover plate and installing a nut, wherein the nut has a threaded section and a cavity section, the threaded section cooperates with the thread of the screw, and the cavity section is tightly matched with the coupling section (without thread) of the screw (a seal is provided); that is, a chip groove is formed between the cavity section and the screw to collect metal debris generated by the rotating screw, thereby preventing the metal debris from falling into the filter cavity.

[0005] The above solution still generates metal chips, and there is a risk that the metal chips will be brought into the filter cavity during the up and down movement of the screw. The locking method still relies on the mutual matching of threads, and there are still problems of thread deformation and screw loosening.

[0006] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0007] The main purpose of the present invention is to provide a tuning structure to prevent the tuning screw from generating metal debris and to maintain the stability of the tuning screw.

[0008] To achieve the above object, the present invention provides a tuning structure, including a tuning cover, a card set, a tuning screw and an outer nut, wherein the tuning cover is covered at the opening of the filter cavity, and the tuning screw is used to adjust the tuning frequency of the filter, wherein:

[0009] The cover plate is provided with a hole for the card set to pass through, the hole having an upper portion and an outwardly inclined portion transitionally connected to the upper portion, the upper portion being located above the inclined portion;

[0010] The clamping kit comprises a connecting section with internal and external threads and a flange connected to one end of the connecting section, the flange protrudes outward to form a clamping protrusion matching the inclined portion, and the flange protrudes inward to form a clamping ring matching the tuning screw; the flange is provided with split grooves at intervals in the circumferential direction;

[0011] The tuning screw and the internal thread of the card set are connected by a force-free thread, and the external nut is connected by the external thread of the card set.

[0012] Preferably, the inclined portion is an inclined plane.

[0013] Preferably, the inclination angle of the inclined portion is 45° to 85°

[0014] Preferably, the inclined portion is an inclined curved surface, the arc of a generatrix of the inclined curved surface protrudes inwardly and the arc is tangent to the upper portion.

[0015] Preferably, the vertical height of the upper portion is not less than the vertical height of the inclined portion.

[0016] Preferably, the clamping protrusion has a conical inclined surface, and the inclination angle of the conical inclined surface is smaller than the inclination angle of the inclined portion.

[0017] Preferably, there is a gap between the clamping ring and the tuning screw.

[0018] Preferably, the splitting groove extends toward the connecting section.

[0019] Preferably, a smooth section is provided between the connecting section of the card set and the card protrusion, and the splitting groove extends toward the smooth section.

[0020] Preferably, a gasket or sealing material is provided on the ferrule.

[0021] On the other hand, the present application proposes a filter, including the above-mentioned tuning structure, for communication filtering.

[0022] The present application proposes a tuning structure, including a tuning cover, a card set, a tuning screw and an external nut. The tuning cover is covered at the opening of the filter cavity, and the tuning screw is used to adjust the tuning frequency of the filter, wherein a hole for the card set to pass through is opened on the cover, the hole has an upper part and an outwardly inclined inclined part transitionally connected to the upper part, and the upper part is located above the inclined part; the card set includes a connecting section with internal and external threads and a flange connected to one end of the connecting section, the flange protrudes outward to form a clamping protrusion matching the inclined part, and the flange protrudes inward to form a clamping ring matching the tuning screw; split grooves are opened at intervals along the circumference of the flange; the internal thread of the tuning screw and the card set is a stress-free threaded connection. The above tuning structure is to add a card set between the tuning cover and the tuning screw. A split groove is set on the flange at one end of the card set so that the end of the card set is elastic. The card convexity has an inclined surface, which matches the bell mouth of the tuning cover. The flange of the card set protrudes inward to form a clamping ring for clamping the tuning screw. The outer nut and the card set cooperate with each other to provide locking force, so that the flange of the card set is elastically tightened, thereby clamping the tuning screw. At the same time, the tuning screw does not produce metal debris, thereby ensuring the working stability of the filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a cross-sectional view of a conventional cavity filter and tuning structure.

[0024] Figure 2 It is a cross-sectional view of a tuning structure involved in an embodiment of the present application.

[0025] Figure 3a It is a schematic diagram of the three-dimensional structure of the tuning cover plate involved in the embodiment of the present application.

[0026] Figure 3b It is a cross-sectional view of the tuning cover plate involved in the embodiment of the present application.

[0027] Figure 4a It is a schematic diagram of the three-dimensional structure of the card kit involved in the embodiment of the present application.

[0028] Figure 4b It is a cross-sectional view of the card kit involved in the embodiment of the present application.

[0029] Figure 5 yes Figure 2 A is an enlarged view of the middle image.

[0030] Figure 6 It is a cross-sectional view of another tuning structure involved in an embodiment of the present application.

[0031] Figure 7 It is a cross-sectional view of another card kit involved in an embodiment of the present application.

[0032] Figure Number and Name:

[0033] 20. Tuning structure;

[0034] 21, tuning cover; 21a, hole; 211, upper part; 212, inclined part;

[0035] 22, card set; 22a, hole; 221, connecting section; 222, card convex; 2221, inclined surface; 2222, flange; 2223, split groove; 223, smooth section; 2231, groove;

[0036] 23. Tuning screw;

[0037] 24. External nut;

[0038] 30. Tuning structure.

[0039] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0040] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings of the embodiments of the present disclosure. Obviously, the described embodiments are part of the embodiments of the present disclosure, rather than all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present disclosure.

[0041] Traditional cavity filters such as Figure 1 As shown, it includes a housing 11, a tuning cover plate 12, a resonator 13, a screw 14 and a nut 15. The tuning cover plate 12 covers the opening of the housing 11 to enclose a filter cavity 16. The nut 15 is used to lock the screw 14. When the frequency needs to be adjusted, first, the nut 15 is loosened, and then the screw 14 is adjusted to obtain the tuning frequency, and the nut 15 is re-tightened to lock the screw 14 and the tuning cover plate 12. When the frequency needs to be adjusted, the nut 15 needs to be repeatedly loosened or tightened. This method of locking the screw 14 by thread causes metal debris to be generated between the screw 14 and the tuning cover plate 12 or the nut. The metal debris falls into the filter cavity 16 and affects the filtering effect. In addition, the teeth on the screw 14 and the teeth on the tuning cover plate 12 are both small bevels. Once the stress-bearing teeth are deformed, it is easy to cause the locked screw 14 to loosen, thereby affecting the filtering effect of the filter.

[0042] In view of this, the present invention provides a tuning structure to solve the problem in the related art that the frequency adjustment (tuning) screw is fastened by means of threaded connection and metal debris is inevitably generated during the adjustment process, which enters the filter cavity and affects the filtering effect of the filter.

[0043] The optional embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0044] The present application provides a tuning structure 20, which is applied to a cavity filter. Figure 2 , including a tuning cover plate 21, a card set 22, a tuning screw 23 and an outer nut 24. The card set 22 has internal and external threads, the card set 22 passes through the hole of the tuning cover plate 21 and is locked with the outer nut, and the tuning screw 23 is matched with the internal thread of the card set 22.

[0045] The tuning structure 20 is used for a cavity filter or a coaxial cavity filter to adjust the resonant frequency of the filter. Generally, the tuning cover 21 is used to cover the housing of the filter. The housing of the filter forms a cavity. The shape of the cavity is not limited, including circular, square, rectangular, etc. It can also be cascaded by multiple cavities, and coupling windows are set between the cavities. A resonant rod (device) is set in the cavity. The resonant rod (device) is a key component of the filter and determines the resonant frequency of the filter together with the cavity.

[0046] See also Figure 3a and Figure 3b The tuning cover 21 has a hole 21 a therein, so that the card set 22 can pass through from below the tuning cover 21 . Figure 3b The example shows the structure of the hole 21a, the hole 21a includes an upper portion 211 and an inclined portion 212 transitionally connected to the upper portion 211, the upper portion 211 is located above the inclined portion 212; the upper portion 211 can be an inclined surface, a vertical surface, a curved surface or a step surface, the inclined portion 212 is an outwardly inclined surface, including a plane or a curved surface forming a bell mouth, the arc of the curved surface generatrix protrudes into the hole 21a and the arc is tangent to the upper portion 211; the inclination angle ɑ of the inclined portion 212 is: 0°<ɑ<90°, preferably, 45°<ɑ<85°, more preferably, 60°<ɑ<75°.

[0047] In the above-mentioned tuning cover 21, the vertical height of the upper part 211 and the vertical height of the inclined part 212 constitute the thickness of the tuning cover 21, and the vertical height of the upper part 211 is not less than the vertical height of the inclined part 212, that is, a≥b, preferably, b=(1 / 10~1 / 3)a.

[0048] In the above-mentioned tuning cover plate 21, the position and number of the holes 21a match the resonant rod (device) in the cavity, and this application does not impose any limitation on this;

[0049] In the above description, when the upper portion 211 is an inclined surface or a curved surface, the upper and lower positions of the hole are both bell mouths or hyperbolic grooves. This structure has good strength, small deformation, and resistance to compressive stress.

[0050] See also Figure 4a and Figure 4bThe clamping kit 22 includes a connecting section 221 with internal and external threads, and a flange 222 connected to one end of the connecting section 221. The flange 222 protrudes outward to form a clamping protrusion 2221 with a conical slope. The flange 222 protrudes inward to form a clamping ring 2222. A split groove 2223 is provided along the circumference of the flange 222. The split groove 2223 extends a certain distance toward the connecting section 221. In order to facilitate processing and balance force, the split groove 2223 can be symmetrically arranged.

[0051] The connecting section 221 of the clamping sleeve 22 in the above embodiment can pass through the hole 21a, and the clamping protrusion 2221 on the clamping sleeve 22 abuts against the inclined portion 212 of the hole 21a on the tuning cover 21. In order to ensure that the clamping protrusion 2221 and the inclined portion 212 have relatively stable contact, the inclination angle of the conical inclined surface on the clamping protrusion 2221 is in the same range as the inclination angle of the inclined portion 212. Preferably, the inclination angle of the conical inclined surface on the clamping protrusion 2221 is slightly smaller than the inclination angle of the inclined portion 212. When locking by the outer nut 24, it is ensured that the clamping protrusion 2221 and the inclined portion 212 have maximum surface contact and / or maximum complete ring contact.

[0052] In the above embodiment, the internal thread of the card set 22 and the tuning screw 23 are connected by force-free threads, so that the length of the tuning screw 23 can be freely adjusted, and there is no locking force between the internal thread of the card set 22 and the thread of the tuning screw 23. Figure 5 As shown, the tuning screw 23 is screwed into the card set 22 , and a gap exists between the clamping ring 2222 of the card set 22 and the tuning screw 23 .

[0053] It should be noted that the thread length on the tuning screw 23 meets the adjustment requirements of the tuning frequency. The end of the tuning screw 23 is a threadless cylinder to reduce interference with the filtering performance. The position of the clamping ring 2222 of the card set 22 corresponds to the cylinder of the tuning screw 23.

[0054] In the above description, the tuning screw 23 is screwed into the card set 22 (hole 22a), and then the card set 22 is passed through the hole 21a of the tuning cover plate 21 and locked with the outer nut 24. The clamping protrusion 2221 of the card set 22 contacts the inclined portion 212 of the hole 21a of the tuning cover 21. At this time, the frequency tuning control can be performed through the tuning screw 23. After the adjustment is completed, the outer nut 24 is further tightened to generate a locking force on the card set 22. The clamping protrusion 2221 of the card set 22 generates an upward force on the inclined portion 212 of the hole 21a on the tuning cover 21, and the inclined portion 212 generates a reaction force on the clamping protrusion 2221. Since the flange 222 is provided with a split groove 2223, the clamping ring 2222 on the flange 222 shrinks and presses toward the center of the circle, and the clamping ring 2222 clamps the tuning screw 23. The outer nut 24 is further tightened, and the clamping ring 222 continues to tighten, thereby clamping the tuning screw 23 to fix the tuning screw 23.

[0055] When the frequency needs to be adjusted multiple times, loosen the outer nut 24, the locking force of the card set 22 disappears, and the clamping ring 2222 returns to its original state. The tuning screw 23 and the card set 22 are connected by a force-free thread. During the adjustment process, there is no locking force between the threads, so no metal debris is generated. After the adjustment is completed, tighten it with the outer nut 24 to fix the tuning screw 23, thereby ensuring the working stability of the filter.

[0056] When the outer nut 24 is repeatedly tightened, the clamping sleeve 22 and the outer nut 24 generate a pre-tightening force, and the outer threads of the clamping sleeve 22 and the threads of the outer nut may generate metal debris.

[0057] In the above structure, the connection position between the outer nut 24 and the card kit 22 is located above the tuning cover 21. A gasket or sealing material can be set on the card kit 22 to prevent metal debris generated between the outer nut 24 and the card kit 22 from entering the gap between the hole 21a of the tuning cover 21 and the card kit 22.

[0058] The present application provides another tuning structure 30. Compared with the structure in the above embodiment, the difference is that a smooth section 223 is provided between the connecting section 221 and the flange 222 on the card set 22. Figure 6 and Figure 7 The split groove 2223 extends toward the smooth section 223 and does not extend to the inner and outer threads, thereby avoiding stress concentration of the card set 22 during processing or metal debris generated during adjustment, and shear stress concentration when the outer nut 24 is tightened, which affects the service life of the card set 22.

[0059] The vertical distance of the smooth section 223 is equivalent to the vertical height of the upper portion 211 of the tuning cover 21. The smooth section 223, the upper portion 211 and the protrusion 2221 form a groove 2231. A seal or sealant can be set in the groove 2231 to prevent metal debris from entering the filter cavity through the split groove 2223.

[0060] It should be noted that the tuning screw 23 and the outer nut 4 are both conventional structures and belong to the prior art. For example, the tuning screw 23 has an adjustable pattern, such as a cross pattern, a hexagonal pattern, etc.

[0061] It can be known that a seal (not shown in the figure) can be arranged above the clamping ring 2222 of the card set 22 , and the seal is sleeved on the cylinder of the tuning screw 23 .

[0062] It should be noted that after the fastening is completed, the bottom surface of the flange 222 can be flush or nearly flush with the bottom of the tuning cover plate 21 .

[0063] It can be known that the tuning cover plate 21, the card set 22, the tuning screw rod 23 and the outer nut 24 in the above embodiment are all made of metal, and the part extending into the inner side of the cavity can be plated with metal silver or gold.

[0064] The present application also proposes a filter having the tuning structure 20 in the above embodiment, which can be used in communication equipment.

Claims

1. A tuning structure, comprising a tuning cover plate (21), a card set (22), a tuning screw (23) and an outer nut (24), wherein the tuning cover plate (21) covers the opening of the filter cavity, and the tuning screw (23) is used to adjust the tuning frequency of the filter, characterized in that: The cover plate (21) is provided with a hole (21a) for the card set (22) to pass through, the hole (21a) having an upper portion (211) and an outwardly inclined portion (212) transitionally connected to the upper portion (211), the upper portion (211) being located above the inclined portion (212); The clamping assembly (22) comprises a connecting section (221) with internal and external threads and a flange (222) connected to one end of the connecting section (221); the flange (222) protrudes outward to form a clamping protrusion (2221) matching the inclined portion (212); the flange (222) protrudes inward to form a clamping ring (2222) matching the tuning screw (23); the flange (222) is provided with split grooves (2223) at intervals in the circumferential direction; The tuning screw (23) and the internal thread of the clamping set (22) are connected in a force-free threaded manner, and the external nut (24) is connected to the external thread of the clamping set (22).

2. The tuning structure according to claim 1, characterized in that: The inclined portion (212) is an inclined plane.

3. The tuning structure according to claim 2, characterized in that: The inclined portion (212) has an inclination angle of 45° to 85°.

4. The tuning structure according to claim 1, characterized in that: The inclined portion (212) is an inclined curved surface, the arc of the generatrix of the inclined curved surface protrudes inwards and the arc is tangent to the upper portion (211).

5. The tuning structure according to any one of claims 1 to 4, characterized in that: The locking protrusion (2221) has a conical inclined surface, and the inclination angle of the conical inclined surface is smaller than the inclination angle of the inclined portion (212).

6. The tuning structure according to claim 5, characterized in that: There is a gap between the clamping ring (2222) and the tuning screw (23).

7. The tuning structure according to claim 6, characterized in that: The splitting groove (2223) extends toward the connecting section (221).

8. The tuning structure according to claim 1, characterized in that: A smooth section (223) is also provided between the connecting section (221) of the card set (22) and the card protrusion (222), and the split groove (2223) extends toward the smooth section (223).

9. The tuning structure according to any one of claims 6 to 8, characterized in that: A gasket or sealing material is provided on the ferrule (22).

10. A filter comprising the tuning structure described in any one of claims 1 to 9, used for communication filtering.

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