Aluminum shell capacitor with insulating sleeve

Abstract

The utility model provides a kind of aluminium shell capacitor with insulating sleeve, including aluminium shell capacitor body, heat shield, insulating sleeve, rubber cover, conductive pin, the inner side wall of rubber cover is provided with dovetail groove to opposite side, the position of the outer side surface upper portion of insulating sleeve is set with dovetail lug corresponding with dovetail groove;The inner side wall of rubber cover and between adjacent dovetail groove is set with buckle groove, the position of the outer side surface upper portion of insulating sleeve is set with buckle tight lug corresponding with buckle groove;The heat shield includes from inside to outside: nano reflection coating, aerogel felt layer, glass fiber reinforced PP layer;The lower portion of insulating sleeve inner side surface is provided with annular groove, and water-swelling resin layer is embedded in the annular groove.Simplify installation process on the basis of ensuring installation stability, improve the thermal aging life of insulating sleeve, improve the reliability of high humidity environment.

Description

Technical Field

[0001] This utility model relates to the field of aluminum capacitor technology, and in particular to an aluminum-cased capacitor with an insulating sleeve. Background Technology

[0002] Chinese Patent Publication No. CN223321135U, published on September 9, 2025, discloses a dry-type aluminum-shell capacitor with an insulating sleeve, including a capacitor assembly comprising an aluminum shell and a rubber plug. The rubber plug is fixedly connected to the top of the aluminum shell. An insulating assembly includes an insulating sleeve, a fixing block, a first telescopic spring, a movable ring, a through hole, and a fixing groove. The insulating sleeve is fitted onto the outer side of the aluminum shell, and the fixing block is fixedly connected to the top of the insulating sleeve around its perimeter. The invention has the advantage of fixing the insulating sleeve by moving the insulating sleeve and fixing plate towards the rubber plug, causing the fixing plate to enter the rubber plug and move the movable ring inward. The inward movement of the movable ring compresses the first telescopic spring, and then rotating the insulating sleeve causes the fixing plate to rotate. When the fixing plate rotates to the outer end of the fixing groove, under the elastic force of the first telescopic spring, the fixing plate enters the fixing groove and is blocked by the fixing ring. The existing technology has the following drawbacks: 1. The fixing block needs to enter the rubber stopper through the through hole and then rotate to align with the fixing groove, relying on the restoring force of the first telescopic spring. This operation is cumbersome and requires precise alignment; otherwise, the fixing block will not be in place, causing the insulating sleeve to loosen. 2. The heat insulation sleeve only indirectly contacts the aluminum shell through ball bearings, but heat from the aluminum shell can still be transferred through the air or contact points, leading to aging of the insulating sleeve. 3. The rubber stopper relies solely on physical sealing, lacking an active sealing mechanism. The through hole and the opening of the fixing groove can become moisture inlets, which can easily cause capacitor failure, especially in humid environments. Given these circumstances, a solution is urgently needed. Utility Model Content

[0003] Based on this, the purpose of this utility model is to provide an aluminum-cased capacitor with an insulating sleeve, which simplifies the installation process while ensuring installation stability, improves the thermal aging life of the insulating sleeve, and enhances reliability in high-humidity environments.

[0004] This utility model provides an aluminum-cased capacitor with an insulating sleeve, comprising an aluminum-cased capacitor body, a heat-insulating sleeve, an insulating sleeve, a rubber cover, and conductive leads. The heat-insulating sleeve is correspondingly sleeved on the outer side of the aluminum-cased capacitor body, and the insulating sleeve is correspondingly sleeved on the outer side of the heat-insulating sleeve. One end of the conductive leads is connected to the aluminum-cased capacitor body, and the side of the aluminum-cased capacitor body with the conductive leads is fixedly connected to the rubber cover. The conductive leads penetrate the rubber cover and extend beyond the rubber cover.

[0005] The inner sidewall of the rubber cover is provided with dovetail grooves on opposite sides, and the upper part of the outer side of the insulating sleeve is provided with dovetail protrusions at positions corresponding to the dovetail grooves; the inner sidewall of the rubber cover is provided with a buckle groove between adjacent dovetail grooves, and the upper part of the outer side of the insulating sleeve is provided with a buckling protrusion at positions corresponding to the buckle grooves.

[0006] The heat insulation sleeve comprises, from the inside out: a nano-reflective coating, an aerogel felt layer, and a fiberglass-reinforced PP layer;

[0007] An annular groove is provided on the lower part of the inner side of the insulating sleeve, and a water-swellable resin layer is pre-embedded in the annular groove.

[0008] Preferably, the entrance of the dovetail groove is provided with a guide groove entrance ramp with an angle of 10°-20°.

[0009] Preferably, the expansion rate of the water-swellable resin layer is set to 150%-200%, and the response humidity threshold is ≥70%RH.

[0010] Preferably, the bottom of the annular groove is provided with a micro-hole array.

[0011] Preferably, the nano-reflective coating is configured as an alumina-based composite material layer with a reflectivity ≥90%.

[0012] Preferably, the water-swellable resin layer is a sodium acrylate-acrylamide copolymer layer with a glass transition temperature Tg ≤ -20℃.

[0013] Preferably, the outer surface of the glass fiber reinforced PP layer is coated with a polyvinylidene fluoride wear-resistant layer.

[0014] Preferably, the outer surface of the rubber cover is provided with a sheath for the conductive pins to extend out.

[0015] The beneficial effects of this utility model are as follows: the inner sidewall of the rubber cover is provided with dovetail grooves on opposite sides, and the upper part of the outer side of the insulating sleeve is provided with dovetail protrusions at positions corresponding to the dovetail grooves. Through the cooperation of the dovetail grooves and dovetail protrusions, combined with the inner sidewall of the rubber cover and the buckling grooves provided between adjacent dovetail grooves, and the upper part of the outer side of the insulating sleeve is provided with buckling protrusions at positions corresponding to the buckling grooves, the buckling protrusions and buckling grooves are further fixed, ensuring the stability of the installation and simplifying the installation process; the heat insulation sleeve includes a nano-reflective coating, an aerogel felt layer, and a glass fiber reinforced PP layer from the inside out, improving the thermal aging life of the insulating sleeve; an annular groove is opened at the lower part of the inner side of the insulating sleeve, and a water-swellable resin layer is pre-embedded in the annular groove, improving the reliability in high humidity environments. Attached Figure Description

[0016] Figure 1 This is an exploded view of the present invention.

[0017] Figure 2 This is a structural view of the present invention.

[0018] Figure 3 This is a top view of the insulating sleeve.

[0019] Figure 4 This is a cross-sectional view of the insulation jacket.

[0020] The attached figures are labeled as follows: aluminum shell capacitor body 13, heat insulation sleeve 12, insulating sleeve 11, rubber cover 10, conductive pin 14, sheath 15, dovetail groove 16, buckle groove 17, water-swellable resin layer 18, micro-hole array 19, dovetail protrusion 20, buckling protrusion 21, annular groove 22, nano-reflective coating 25, aerogel felt layer 24, and glass fiber reinforced PP layer 23. Detailed Implementation

[0021] To further understand the features, technical means, and specific objectives and functions achieved by this utility model, the following detailed description of this utility model is provided in conjunction with specific embodiments and accompanying drawings.

[0022] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0023] Please refer to Figures 1-4 As shown, an aluminum-cased capacitor with an insulating sleeve includes an aluminum-cased capacitor body 13, a heat-insulating sleeve 12, an insulating sleeve 11, a rubber cover 10, and conductive leads 14. The heat-insulating sleeve 12 is fitted onto the outer side of the aluminum-cased capacitor body 13, and the insulating sleeve 11 is fitted onto the outer side of the heat-insulating sleeve 12. One end of the conductive lead 14 is connected to the aluminum-cased capacitor body 13, and the side of the aluminum-cased capacitor body 13 with the conductive lead 14 is fixedly connected to the rubber cover 10. The conductive lead 14 passes through the rubber cover 10 and extends out of the rubber cover 10. A protective sleeve 15 is provided on the outer surface of the rubber cover 10 for the conductive lead 14 to extend out.

[0024] The inner sidewall of the rubber cover 10 is provided with dovetail grooves 16 on opposite sides, and the upper part of the outer side of the insulating sleeve 11 is provided with dovetail protrusions 20 at positions corresponding to the dovetail grooves 16; the inner sidewall of the rubber cover 10 is provided with a snap groove 17 between adjacent dovetail grooves 16, and the upper part of the outer side of the insulating sleeve 11 is provided with a snap-fit ​​protrusion 21 at positions corresponding to the snap groove 17; in the assembled state, the dovetail protrusions 20 are fitted into the dovetail grooves 16, and the snap-fit ​​protrusions 21 are fitted into the snap grooves 17 to achieve fixation.

[0025] The heat insulation sleeve 12 comprises, from the inside out: a nano-reflective coating 25, an aerogel felt layer 24, and a glass fiber reinforced PP layer 23; the nano-reflective coating 25 is an alumina-based composite material layer with a reflectivity ≥90%. High reflectivity blocks infrared radiation, improving heat reflection efficiency by 40%; electrostatic spraying ensures uniform coating, increasing mass production costs by only 10%.

[0026] The multi-layer composite structure ensures that the temperature rise of the outer surface of the insulation sleeve is ≤15℃ when the aluminum shell temperature is 100℃, and the thermal aging life is increased by 3 times; the thermal conductivity of the aerogel felt is 0.02W / m·K, and the barrier efficiency reaches 95%.

[0027] An annular groove 22 is formed on the lower part of the inner side of the insulating sleeve 11, and a water-swellable resin layer 18 is embedded in the annular groove 22. The expansion rate of the water-swellable resin layer 18 is set to 150%-200%, and the response humidity threshold is ≥70%RH. It automatically expands to fill gaps when exposed to moisture, improving the sealing performance by 90% in an environment with 80% humidity, thus solving the short circuit risk caused by moisture intrusion at the through holes in the original technology. A micro-pore array 19 is formed circumferentially at the bottom of the annular groove 22. The micro-pore array shortens the expansion response time to within 5 seconds, improving reliability in high humidity environments; the optimized groove size ensures a mass production injection molding yield of ≥99%. The water-swellable resin layer 18 is set as a sodium acrylate-acrylamide copolymer layer with a glass transition temperature Tg≤-20℃, maintaining elasticity at low temperatures (it can still expand at -40℃), expanding the applicable environment of the capacitor to cold regions; Tg≤-20℃ ensures that the material does not crack during thermal cycling, and the cycle life is ≥5,000 cycles.

[0028] The entrance to the dovetail groove 16 is equipped with a guide groove inlet ramp with an angle of 10°-20°. The optimized ramp angle ensures that the dovetail protrusion automatically slides into the guide groove, improving the alignment tolerance to ±0.5mm and reducing the defect rate by 30%.

[0029] The outer surface of the glass fiber reinforced PP layer 23 is coated with a polyvinylidene fluoride (PVDF) wear-resistant layer. The glass fiber reinforced PP layer 23 has a scratch resistance rating of 3H, which improves wear resistance by 5 times; the surface hydrophobicity reduces dirt adhesion by 60% and extends the maintenance cycle.

[0030] In this embodiment, the inner sidewall of the rubber cover is provided with dovetail grooves on opposite sides, and the upper part of the outer side of the insulating sleeve is provided with dovetail protrusions at positions corresponding to the dovetail grooves. Through the cooperation of the dovetail grooves and dovetail protrusions, and combined with the inner sidewall of the rubber cover and the buckling grooves provided between adjacent dovetail grooves, a buckling protrusion is provided at a position corresponding to the buckling groove on the upper part of the outer side of the insulating sleeve. The buckling protrusions and buckling grooves are used for further fixation, ensuring the stability of the installation while simplifying the installation process. The heat insulation sleeve includes a nano-reflective coating, an aerogel felt layer, and a glass fiber reinforced PP layer from the inside out, which improves the thermal aging life of the insulating sleeve. An annular groove is opened at the lower part of the inner side of the insulating sleeve, and a water-swellable resin layer is pre-embedded in the annular groove to improve the reliability in high humidity environments.

[0031] The process framework of this embodiment is as follows:

[0032] Raw material preparation → Rubber cover assembly manufacturing, insulation sleeve assembly manufacturing, heat insulation sleeve assembly manufacturing → Capacitor body pre-assembly → Insulation sleeve assembly → Sealing layer activation → Final testing → Packaging and warehousing.

[0033] Rubber cover assembly manufacturing:

[0034] 1. Produced using a two-color injection molding machine, the main material is silicone rubber (hardness 70±5 Shore A), embedded in a hydrogel groove mold, with a groove depth of 0.8mm±0.05mm and a width of 2.5mm, and simultaneously injection molding of dovetail grooves (with 10°-20° slopes) and snap-fit ​​grooves.

[0035] 2. Micro-hole processing: A laser drilling machine is used to drill an array of micro-holes at the bottom of the annular groove.

[0036] 3. Hydrogel pre-embedding: Sodium acrylate-acrylamide copolymer is injected using a metered dispensing machine.

[0037] Insulating sleeve assembly manufacturing:

[0038] 1. Matrix injection molding: Glass fiber reinforced PP matrix is ​​formed using an injection molding machine (including dovetail protrusions / fastening protrusions).

[0039] 2. Polyvinylidene fluoride (PVDF) coating: A classic coating line and UV curing oven are used to electrostatically coat the outer surface with PVDF.

[0040] Thermal insulation sleeve assembly manufacturing:

[0041] 1. Aerogel lamination: A hot press laminating machine is used to laminate aerogel felt with a glass fiber reinforced PP substrate.

[0042] 2. Nano-coating: An alumina-based coating (reflectivity ≥90%) is electrostatically sprayed using vacuum spraying equipment.

[0043] Capacitor assembly and activation:

[0044] 1. Pre-assembly of the main body: Using an automatic spot welding machine and a pneumatic pressing table, 1) aluminum shell capacitor body + conductive pins are welded together; 2) rubber cover is pressed together (conductive pins 14 are sheathed).

[0045] 2. Insulation sleeve assembly: Vibration feeding and robotic arm are used. The dovetail protrusion slides into the guide groove and then the fastening protrusion is snapped into the fastening groove.

[0046] 3. Heat and humidity activation: Aging is performed in a constant temperature and humidity chamber at 80℃ / 85%RH for 30 minutes.

[0047] The above-described embodiments are merely one implementation of this utility model, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. An aluminum-cased capacitor with an insulating sleeve, comprising an aluminum-cased capacitor body (13), a heat-insulating sleeve (12), an insulating sleeve (11), a rubber cover (10), and conductive leads (14), wherein the heat-insulating sleeve (12) is correspondingly sleeved on the outer side of the aluminum-cased capacitor body (13), the insulating sleeve (11) is correspondingly sleeved on the outer side of the heat-insulating sleeve (12), one end of the conductive leads (14) is connected to the aluminum-cased capacitor body (13), the side of the aluminum-cased capacitor body (13) with the conductive leads (14) is fixedly connected to the rubber cover (10), and the conductive leads (14) penetrate the rubber cover (10) and extend out of the rubber cover (10); Its features are: The inner sidewall of the rubber cover (10) is provided with dovetail grooves (16) on opposite sides, and the upper part of the outer side of the insulating sleeve (11) is provided with dovetail protrusions (20) at the position corresponding to the dovetail grooves (16); the inner sidewall of the rubber cover (10) is provided with buckle grooves (17) between adjacent dovetail grooves (16), and the upper part of the outer side of the insulating sleeve (11) is provided with buckle protrusions (21) at the position corresponding to the buckle grooves (17); The heat insulation sleeve (12) comprises, from the inside out: a nano-reflective coating (25), an aerogel felt layer (24), and a glass fiber reinforced PP layer (23); An annular groove (22) is provided on the lower part of the inner side of the insulating sleeve (11), and a water-swellable resin layer (18) is pre-embedded in the annular groove (22).

2. The aluminum-cased capacitor with an insulating sleeve according to claim 1, characterized in that: The entrance of the dovetail groove (16) is provided with a guide groove entrance ramp with an angle of 10°-20°.

3. The aluminum-cased capacitor with an insulating sleeve according to claim 1, characterized in that: The expansion rate of the water-swellable resin layer (18) is set to 150%-200%, and the response humidity threshold is ≥70%RH.

4. The aluminum-cased capacitor with an insulating sleeve according to claim 1, characterized in that: The bottom of the annular groove (22) is provided with a micro-hole array (19).

5. The aluminum-cased capacitor with an insulating sleeve according to claim 1, characterized in that: The nano-reflective coating (25) is configured as an alumina-based composite material layer with a reflectivity ≥90%.

6. The aluminum-cased capacitor with an insulating sleeve according to claim 1, characterized in that: The water-swellable resin layer (18) is a sodium acrylate-acrylamide copolymer layer with a glass transition temperature Tg ≤ -20℃.

7. An aluminum-cased capacitor with an insulating sleeve according to any one of claims 1-6, characterized in that: The outer surface of the glass fiber reinforced PP layer (23) is coated with a polyvinylidene fluoride wear-resistant layer.

8. The aluminum-cased capacitor with an insulating sleeve according to claim 7, characterized in that: The outer surface of the rubber cover (10) is provided with a sheath (15) for the conductive pin (14) to extend out.

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