Capacitor shell and capacitor

Abstract

The utility model relates to a capacitor shell and a capacitor in the technical field of capacitors, and the capacitor shell comprises a shell side wall which is of a cylindrical structure; the edge of the shell bottom is connected to one end of the shell side wall; the shell bottom comprises a middle part and an outer ring part arranged around the middle part, the middle part is provided with an anti-explosion groove, and the anti-explosion groove extends from the center of the middle part to the edge of the middle part. According to the capacitor shell, the anti-pressure capability can be enhanced, control over negative effects caused by internal pressure is enhanced, the speed of valve opening, liquid leakage and failure phenomena is slowed down, and the service life of a product is prolonged.

Description

Technical Field

[0001] The present application relates to the technical field of capacitors, and particularly to a capacitor housing and a capacitor. Background Art

[0002] The phenomenon of leakage and failure due to excessive internal pressure in aluminum electrolytic capacitors is one of the important factors affecting the service life of aluminum electrolytic capacitors. During the operation of aluminum electrolytic capacitors, various gases such as hydrogen, oxygen, and water vapor will inevitably be generated, resulting in a continuous increase in the internal pressure of the product. When the internal pressure is greater than the external pressure and reaches the explosion-proof pressure of the aluminum shell, the explosion-proof valve at the bottom of the aluminum shell of the aluminum electrolytic capacitor will open, and the electrolyte inside the core package will leak out, causing the product to fail. Especially when using stacked foil aluminum electrolytic capacitor products, a large amount of hydrogen generated during the repair of the oxide film is reduced by adding hydrogen scavengers. However, the special additive manufacturing process of the stacked foil makes the stacked foil more likely to generate cracks when wound into a core package, resulting in a significant increase in the high-temperature leakage current of the manufactured product, more hydrogen generated during operation, and an excessive amount of hydrogen scavengers will affect the performance of the electrolyte. And the normal addition amount of hydrogen scavengers cannot consume the excessive hydrogen generated, and the generation of more hydrogen will further increase the internal pressure of the product, accelerate the occurrence of the leakage and failure problem, end the operation in advance, and greatly shorten the product life. The opening valve and leakage failure of aluminum electrolytic capacitors will not only cause the loss of capacitor functionality and affect the normal operation of the circuit board, but also the leaked electrolyte will corrode the surrounding electronic components and damage the entire circuit board. Summary of the Utility Model

[0003] In view of the problems existing in the background art, the present application provides a capacitor housing and a capacitor. The capacitor housing can enhance the control of the negative impact caused by the internal pressure, slow down the speed of the occurrence of the opening valve and leakage failure phenomenon, and increase the product life.

[0004] According to one aspect of the present utility model, there is provided a capacitor housing, including: a shell side wall, the shell side wall having a cylindrical structure; a shell bottom, an edge of the shell bottom being connected to one end of the shell side wall; the shell bottom including a middle part and an outer ring part arranged around the middle part, the middle part being provided with an explosion-proof groove, the explosion-proof groove extending from the center of the middle part to the edge of the middle part.

[0005] In some embodiments of the present utility model, the ratio of the distance from the center of the middle part to its edge to the ring width of the outer ring part is 2 - 4.

[0006] In some embodiments of the present utility model, the thickness of the middle part gradually becomes thicker from the center of the middle part to the edge of the middle part.

[0007] In some embodiments of the present utility model, the ratio of the thickness of the middle part at the explosion-proof groove to the thickness of the outer ring part is 0.1 - 1.

[0008] In some embodiments of the present utility model, the cross-section of the explosion-proof groove is an inverted trapezoid.

[0009] In some embodiments of the present utility model, the inclination angles of the two inclined surfaces of the inverted trapezoid relative to the bottom surface are 30° - 60°.

[0010] In some embodiments of the present utility model, the explosion-proof grooves are evenly distributed around the center of the middle part.

[0011] In some embodiments of the present utility model, the number of the explosion-proof grooves is three, four, five or six.

[0012] In some embodiments of the present utility model, the thickness of the shell sidewall is 0.2 - 0.8 mm.

[0013] According to another aspect of the present utility model, there is provided a capacitor, including the above-mentioned capacitor housing.

[0014] The present utility model provides a capacitor housing. By dividing the bottom of the shell into inner and outer regions and arranging explosion-proof grooves in the middle part to form a valve structure, the capacitor housing has higher compressive strength and hardness, increases the compressive capacity of the capacitor housing, can control the negative impact caused by the internal pressure (excessive internal pressure is likely to cause deformation of the aluminum shell, valve opening and leakage or even explosion), slows down the problem of liquid leakage failure of capacitors, especially multilayer foil aluminum electrolytic capacitors, prolongs the product life, and further adopts aluminum-manganese-silicon alloy, aluminum-manganese-iron alloy or aluminum-manganese-iron-silicon alloy with high aluminum content, etc., significantly improves the tensile strength and hardness of the aluminum substrate, further enhances the ability of the aluminum shell of the multilayer foil aluminum electrolytic capacitor to withstand internal pressure, and at the same time does not affect the elongation rate of the material, meeting the manufacturing process of aluminum shell forming. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. And throughout the drawings, the same reference numerals are used to represent the same components. In the drawings:

[0016] Figure 1 is the overall structural schematic diagram of the capacitor housing of the embodiment of the present application.

[0017] Figure 2 is the top view showing the internal structure of the capacitor housing.

[0018] Figure 3 is a cross-sectional view of the A-A section in this application Figure 2 .

[0019] The reference numerals in the drawings are represented as follows: 1, the side wall of the shell; 2, the bottom of the shell; 21, the middle part; 22, the outer ring part; 23, the explosion-proof groove; h, the thickness of the middle part 21 at the explosion-proof groove 23; α, the inclination angle of the two inclined surfaces of the inverted trapezoid relative to the bottom surface. Detailed implementation manners

[0020] It should be clear that the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application.

[0021] When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation manners described in the following exemplary embodiments do not represent all the implementation manners consistent with this application. On the contrary, they are only examples of the devices and methods consistent with some aspects of this application as detailed in the appended claims.

[0022] In the description of this application, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances. In addition, in the description of this application, unless otherwise specified, "a plurality of" means two or more. "And / or" describes the association relationship of associated objects and indicates that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. The character " / " generally represents an "or" relationship between the front and rear associated objects.

[0023] The present utility model discloses a capacitor housing. As Figure 1 and Figure 2 shown, the capacitor housing includes a shell side wall 【1】 and a shell bottom 【2】; wherein, the shell side wall 【1】 has a cylindrical structure, and the edge of the shell bottom 【2】 is connected to one end of the shell side wall 【1】; the shell bottom 【2】 includes a middle part

[21] and an outer ring part

[22] arranged around the middle part

[21] , and an explosion-proof groove

[23] is provided in the middle part

[21] , and the explosion-proof groove

[23] extends from the center of the middle part

[21] to the edge of the middle part

[21] .

[0024] In some embodiments of the present utility model, the bottom shell 2 is divided into inner and outer regions, and an explosion-proof groove 23 is provided in the middle part 21 to form a valve structure, so that the capacitor shell has higher compressive strength and hardness, increases the compressive capacity of the capacitor shell, and can control the negative impact caused by the internal pressure (excessive internal pressure is likely to cause deformation of the aluminum shell, valve opening leakage or even explosion), slow down the problem of liquid leakage failure of capacitors, especially laminated foil aluminum electrolytic capacitors, and extend the product life.

[0025] In some embodiments of the present utility model, the shell side wall 1 has a cylindrical structure, including but not limited to a cylindrical structure or a polygonal cylindrical structure; correspondingly, the bottom shell 2 can adopt a circular plate structure or a polygonal sheet structure; preferably, the shell side wall 1 adopts a cylindrical structure, and the bottom shell 2 adopts a circular plate structure adapted to the cylindrical structure.

[0026] It should be noted that when the bottom shell 2 has a circular plate structure, the middle part 21 and the outer ring part 22 are an inner circle and an outer ring respectively, and the two are coaxially arranged, and the valve structure formed by a plurality of explosion-proof grooves 23 is a concentric circle valve structure.

[0027] In addition, when the bottom shell 2 has a polygonal sheet structure such as a square, the middle part 21 and the outer ring part 22 are an inner square and an outer square ring respectively, and the two are concentrically arranged.

[0028] In some embodiments of the present utility model, as Figure 2 shown, the ratio of the distance from the center of the middle part 21 to its edge to the ring width of the outer ring part 22 is 2-4. For example, the ratio of the two is 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, etc.

[0029] By setting the ratio of the distance from the center of the middle part 21 to its edge to the ring width of the outer ring part 22 to 2-4, and then providing an explosion-proof groove 23 on the middle part 21 within this range to form a valve structure, better compressive strength can be provided and effective pressure relief can be achieved.

[0030] It can be understood that for the ratio of the distance from the center of the middle part 21 to its edge to the ring width of the outer ring part 22 being 2-4, for example, when the middle part 21 and the outer ring part 22 are an inner circle and an outer ring respectively and the two are coaxially arranged, this ratio is the ratio of the radius of the inner circle to the ring width of the outer ring.

[0031] In some embodiments of the present utility model, as Figure 1As shown, the thickness of the bottom shell 2 gradually thickens from the center of the middle part 21 to the edge of the middle part 21, that is, the valve structure formed by the explosion-proof groove 23 has a valve bottom that is relatively thinner near the center of the middle part 21 than at the edge.

[0032] Furthermore, the ratio of the thickness h of the middle part 21 at the explosion-proof groove 23 to the thickness of the outer ring part 22 is 0.1 - 1.

[0033] In the same embodiment, by designing the depth of the explosion-proof groove 23 to be consistent from the center of the middle part 21 to the edge of the middle part 21, that is, the thickness of the middle part 21 at the explosion-proof groove 23 gradually thickens from the center to the edge, the process of opening the explosion-proof valve structure can be better completed.

[0034] In different embodiments, the depth of the explosion-proof groove 23 can be designed according to the explosion-proof pressure of the bottom shell 2 to better complete the process of opening the explosion-proof valve structure.

[0035] In some embodiments of the present utility model, as Figure 3 shown, the cross-section of the explosion-proof groove 23 is an inverted trapezoid.

[0036] Furthermore, the inclination angle α of the two inclined surfaces on both sides of the inverted trapezoid relative to the bottom surface is 30° - 60°.

[0037] In some embodiments of the present utility model, by designing the cross-section of the explosion-proof groove 23 as an inverted trapezoid and cooperating with the design that the thickness of the middle part 21 gradually thickens from the center to the periphery, the control of the process of opening the explosion-proof valve structure can be further improved.

[0038] In some embodiments of the present utility model, the explosion-proof pressure of the bottom shell 2 is 0.8 - 2.0 MPa.

[0039] It should be understood that the depth of the explosion-proof groove 23 and / or the inclination angle of the two inclined surfaces on both sides of the inverted trapezoid relative to the bottom surface can be designed according to the explosion-proof pressure of the bottom shell 2, that is, the required explosion-proof pressure can be obtained by designing the depth of the explosion-proof groove 23 and / or the inclination angle of the two inclined surfaces on both sides of the inverted trapezoid relative to the bottom surface.

[0040] In some embodiments of the present utility model, as Figure 2 shown, a plurality of explosion-proof grooves 23 are evenly distributed around the center of the middle part 21.

[0041] Furthermore, the number of the explosion-proof grooves 23 includes but is not limited to three, four, five, six, etc.

[0042] For example, when the number of the explosion-proof grooves 23 is 3, the explosion-proof valve formed thereby is in a "Y" shape, and when the number of the explosion-proof grooves 23 is 4, the explosion-proof valve formed thereby is in a "cross" shape.

[0043] In some embodiments of the present utility model, such as Figure 1 shown, the thickness d of the shell sidewall 1 is 0.2 - 0.8 mm. For example, the thickness of the shell sidewall 1 is 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, etc.

[0044] In the present utility model, the shell sidewall 1 with such a thickness can well limit the internal gas from exerting pressure on the sidewall, and has better compressive strength and hardness.

[0045] Furthermore, the control of the thickness of the shell sidewall 1 is achieved by making shell molds with different thicknesses. The shell sidewall 1 with a certain thickness can improve the gas pressure-bearing range inside the product.

[0046] Furthermore, the shell bottom 2 can adopt the same or different thickness as the shell sidewall 1.

[0047] In some embodiments of the present utility model, the materials of the shell sidewall 1 and the shell bottom 2 are aluminum alloy, such as aluminum-manganese-silicon alloy, aluminum-manganese-iron alloy or aluminum-manganese-iron-silicon alloy with a high aluminum content, etc.

[0048] For example, in the aluminum-manganese-iron-silicon alloy, the aluminum content > 99%, the manganese content is 0.001 - 1%, the iron content is 0.1 - 1%, and the silicon content is 0.01 - 1%. Compared with ordinary aluminum shell raw materials, this alloy significantly improves the tensile strength and hardness of the aluminum base material, enhances the ability of the capacitor, especially the aluminum shell finished product of the laminated foil aluminum electrolytic capacitor, to withstand internal pressure, and at the same time does not affect the elongation rate of the material, meeting the manufacturing process of aluminum shell forming.

[0049] Table 1 Comparison of chemical compositions of two aluminum shells

[0050]

[0051] Table 2 Comparison of performances of two aluminum shells

[0052] Material Hardness HB Tensile strength Elongation Ordinary aluminum shell 21.5 70MPa 50％ Aluminum-manganese-ferrosilicon alloy aluminum shell 28.2 87.9MPa 50％

[0053] The present utility model also proposes a capacitor, and this capacitor includes the above-mentioned capacitor housing.

[0054] Furthermore, the anode foil used in this capacitor is a laminated foil, and is not limited to specifications and models, such as the specification of 450V 1000μF 30*60mm.

[0055] Specifically, this capacitor includes a shell sidewall 1, a shell bottom 2, a core package placed inside the shell sidewall 1, and a sealed cover plate; the core package is composed of a laminated foil, electrolytic paper and a cathode foil, and is impregnated with electrolyte.

[0056] The following presents the specific effects of the capacitor housing described in the present utility model through specific cases.

[0057] The laminated foil aluminum electrolytic capacitor product made by the present utility model is in the specification of 450V 1000μF 30*60mm, and includes a core package, an aluminum shell and a sealed cover plate. The core package is composed of laminated foil, electrolytic paper and cathode foil, and is impregnated with electrolyte. The electrolyte is a system with ethylene glycol as the main solvent, and also includes auxiliary solvents, solutes, hydrogen scavengers, waterproof binders, flashover voltage boosters and pH regulators. The electrolytes used in Comparative Example 1 and Example 1 are the same.

[0058] The aluminum shells used are the ordinary aluminum shell in Comparative Example 1 and the aluminum-manganese-iron-silicon alloy aluminum shell in Example 1 respectively. The wall thickness d of the side wall of the two kinds of aluminum shells is the same, and three explosion-proof grooves are designed at the bottom of the shell, and the three explosion-proof grooves are evenly distributed at the bottom of the shell. Three products are made in each group and placed on the same oven, the same power supply and the same fixture for work. When recording the results, the average value of the data of the three products in each group is taken.

[0059] Comparative Example 1

[0060] A laminated foil aluminum electrolytic capacitor product, in which the core package wound with laminated foil is immersed in the electrolyte, and an ordinary aluminum electrolytic capacitor aluminum shell is used. When the laminated foil aluminum electrolytic capacitor works normally, various gases are generated inside the product, and the gases flow freely inside the aluminum shell. When the working time continues to extend and the internal pressure of the product also continues to increase, the strength of the ordinary aluminum shell is insufficient to effectively resist the change of its shape caused by the pressure, resulting in a slight overall expansion of the aluminum shell and obvious bulging at the bottom of the aluminum shell. Until the explosion-proof valve opens finally and the electrolyte leaks out, the aluminum electrolytic capacitor fails and stops working. Record the initial height of the product, the overall height of the product every 1000 hours, and the time (i.e., the life) and the overall height of the product at the final failure. The test results are shown in Table 3.

[0061] Example 1

[0062] A laminated foil aluminum electrolytic capacitor product, in which the core package wound with laminated foil is impregnated in the electrolyte. The aluminum-manganese-iron-silicon alloy aluminum shell used is based on the raw material aluminum sheet of the ordinary aluminum shell and doped with a certain amount of elements such as manganese, iron and silicon. The specific composition is shown in Table 1. When the aluminum electrolytic capacitor product using the aluminum-manganese-iron-silicon alloy aluminum shell continues to work, although the internal pressure will also gradually increase, due to the excellent compressive strength of the aluminum shell material and the inner wall of the aluminum shell with a certain thickness, as shown in Table 2 for performance comparison, the deformation of the aluminum shell is effectively controlled. Under the same time, the overall expansion of the aluminum-manganese-iron-silicon alloy aluminum shell product is almost none, and the speed of bulging at the bottom of the aluminum shell is relatively very slow. Finally, the life time of the product leaking liquid and failing is almost 1.5 times that of the ordinary aluminum shell product, and the reliability of the product is greatly improved.

[0063] For the stacked foil aluminum electrolytic capacitor product of the above-mentioned Embodiment 1, when the thickness of the side wall 1 of the aluminum shell used is 0.6 mm, it has a better pressure-bearing effect. When the side wall 1 of the shell is too thin, when the internal pressure of the aluminum shell is too large, the overall aluminum shell will expand laterally and deform, resulting in an increase in diameter, and the core package will slosh inside the aluminum shell, posing a risk of breakdown. If the side wall 1 of the shell is too thick, it will occupy too much internal space of the aluminum shell, resulting in the inability of the internal space to meet the loading requirements of the core package.

[0064] For the stacked foil aluminum electrolytic capacitor product of the above-mentioned Embodiment 1, an explosion-proof groove 23 with a certain upper limit of explosion-proof pressure is provided at the bottom 2 of the shell. The magnitude of the explosion-proof pressure depends on the inclination angle α of the explosion-proof groove 23 and the thickness h of the middle part 21 at the explosion-proof groove 23. When the inclination angle of the explosion-proof groove 23 is 30° and the thickness of the middle part 21 at the thinnest part of the explosion-proof groove 23 is 0.5 times the thickness of the outer ring part, the optimal value of the explosion-proof pressure corresponding to the explosion-proof valve is 1.6 MPa at this time. When the explosion-proof pressure is too small, once the internal pressure of the product is greater than the explosion-proof pressure, the problem of valve opening and liquid leakage failure will occur, and the product life is short. When the explosion-proof pressure is too large, a huge impact will be generated instantaneously when the bottom valve opens, and the stacked foil aluminum electrolytic capacitor product is very likely to explode and fall off from the circuit, affecting the operation and safety of the entire circuit.

[0065] Table 3 Height comparison at different working times

[0066] Comparative example 1 Example 1 <![CDATA[Initial height H0 / mm]]> 61.35 61.40 <![CDATA[H 1000 -H0 / mm]]> 1.76 1.08 <![CDATA[H 2000 -H0 / mm]]> 2.51 1.68 <![CDATA[H 3000 -H0 / mm]]> 3.13 2.47 <![CDATA[H 4000 -H0 / mm]]> / 3.22 <![CDATA[H 失效 -H0 / mm]]> 2.97 3.35 Lifetime / h 3070 4564

[0067] Through Comparative Example 1 and Embodiment 1, it can be found that at the same time, the stacked foil aluminum electrolytic capacitor using an aluminum-manganese-iron-silicon alloy aluminum shell has a lower degree of bulging, and the life time of the final product with valve opening failure is longer, which proves that the stacked foil aluminum electrolytic capacitor using an aluminum-manganese-iron-silicon alloy aluminum shell can control the negative impact generated by the internal pressure, slow down the valve opening phenomenon at the bottom of the aluminum shell, increase the product life, and greatly improve the product reliability.

[0068] The capacitor of the present utility model has excellent internal pressure-bearing capacity based on the above-mentioned capacitor housing.

[0069] The above is only a preferred specific embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present utility model should be covered within the protection scope of the present utility model. Therefore, the protection scope of the present utility model should be subject to the protection scope of the claims.

Claims

1. A capacitor housing, characterized in that, Comprising: A shell side wall, the shell side wall being in a cylindrical structure; A shell bottom, the edge of the shell bottom being connected to one end of the shell side wall; The shell bottom includes a middle part and an outer ring part arranged around the middle part. The middle part is provided with an explosion-proof groove, and the explosion-proof groove extends from the center of the middle part to the edge of the middle part.

2. The capacitor housing according to claim 1, wherein, The ratio of the distance from the center of the middle part to its edge to the ring width of the outer ring part is 2 - 4.

3. The capacitor housing according to claim 1, characterized in that, The thickness of the middle part gradually thickens from the center of the middle part to the edge of the middle part.

4. The capacitor housing according to claim 3, characterized in that, The ratio of the thickness of the middle part at the explosion-proof groove to the thickness of the outer ring part is 0.1 - 1.

5. The capacitor housing according to claim 1, characterized in that, The cross-section of the explosion-proof groove is an inverted trapezoid.

6. The capacitor housing according to claim 5, characterized in that, The inclination angles of the two inclined surfaces of the inverted trapezoid relative to the bottom surface are 30° - 60°.

7. The capacitor housing according to claim 1, characterized in that The explosion-proof grooves are evenly distributed around the center of the middle part.

8. The capacitor housing according to claim 7, characterized in that, The number of the explosion-proof grooves is three, four, five or six.

9. The capacitor housing according to any one of claims 1-8, characterized in that, The thickness of the shell side wall is 0.2 - 0.8 mm.

10. A capacitor, characterized in that, Comprising a capacitor housing according to any one of claims 1 to 9.

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