Large capacitor device

Abstract

The utility model discloses a large capacitor device, which relates to the technical field of electrolytic capacitors, and comprises a shell part and a capacitor part, the capacitor part is arranged in the center of the shell part, the capacitor part comprises electrolytic paper and foils, the foils cover the surfaces of the electrolytic paper, the electrolytic paper and the foils are stacked in a staggered manner, and the shell part and the capacitor part are arranged on the shell part. Corrosion holes with large section diameters are formed in the foil. The length of the foil is reduced in a winding mode, and the size of the aluminum electrolytic capacitor is reduced after the foil is wound. In addition, the thickness and the general density of the electrolytic paper used in the utility model are relatively small, and the corrosion holes with large apertures are arranged on the foil, thereby facilitating the penetration of the electrolyte, enabling the capacitor to bear the impact of large ripple current on the premise of a small size, reducing the possibility of breakdown, and prolonging the service life of the capacitor.

Description

Technical Field

[0001] The utility model relates to the technical field of electrolytic capacitors, in particular to a large capacitor device. Background Art

[0002] With the development of industry, spot welding machines have become indispensable equipment, widely used in the automotive, home appliance, machinery, and metal processing industries. With the improvement of welding materials and electrical equipment, the performance and efficiency of spot welding machines have been improved. However, the capacitors in existing spot welding machines cannot withstand the high current ripple, making them unsuitable for the operation of existing high-power spot welding machines. As a result, spot welding machines cannot operate at high intensity for long periods of time, which in turn delays the progress of normal industrial processes. Therefore, a new capacitor device is urgently needed to solve this problem.

[0003] Chinese patent document CN110136961A discloses "an aluminum electrolytic capacitor with extended life and open circuit protection." This invention utilizes an aluminum electrolytic capacitor with extended life and open circuit protection, comprising an element, an aluminum shell, an aluminum cover, and positive and negative leads. The element is mounted within the aluminum shell and sealed with the aluminum cover to form the capacitor body. The positive and negative leads are located on the aluminum shell. The invention is characterized by a heat-dissipating, explosion-proof housing mounted on the outside of the aluminum shell. This housing effectively reduces the operating temperature of the capacitor, thereby extending its service life. Furthermore, the housing improves the product's explosion-proof properties. However, the aluminum electrolytic capacitor described in this patent is not suitable for high current ripple. Utility Model Content

[0004] The utility model mainly solves the technical problem that the original capacitor cannot withstand large current ripple. It provides a large capacitor device. The capacitor part is formed by arranging electrolytic paper with corrosion holes and stacked in an interlaced manner. The capacitor part is arranged in the shell part to withstand large current ripple, thereby improving the service life and adaptability range of the large capacitor device.

[0005] The above-mentioned technical problems of the present invention are mainly solved by the following technical solutions: the present invention includes a shell part and a capacitor part, the capacitor part is arranged in the center of the shell part, the capacitor part includes electrolytic paper and foil, the foil covers the surface of the electrolytic paper, the electrolytic paper and the foil are staggered and stacked, and the foil is provided with corrosion holes with a larger cross-sectional diameter.

[0006] Preferably, the capacitor part includes a plurality of wound electrolytic papers, the foils include cathode foil and anode foil, the cathode foil and anode foil are both arranged on the electrolytic paper, and the electrolytic paper with cathode foil and the electrolytic paper with anode foil are alternately stacked.

[0007] Preferably, the shell portion includes an aluminum shell and a sleeve, the aluminum shell is arranged inside the sleeve, a cover plate is arranged inside the aluminum shell, the cover plate and the aluminum shell are connected to form an inner cavity, and the capacitor portion is arranged in the inner cavity.

[0008] Preferably, a lead bar is provided between the wound electrolytic papers, the lead bar is in the shape of a long flat strip, and one end of the lead bar extends outward from the gap between the electrolytic papers.

[0009] Preferably, the capacitor portion and the shell portion are connected via a lead bar, and the lead bar is connected to the bottom end of the cover plate.

[0010] Preferably, a fastener is provided at the center of the top end of the shell, the guide bar is arranged between the fasteners, and the cross-section of the sleeve is circular.

[0011] Preferably, a hole is provided in the center of the cover plate, the fastener is provided at the top end of the cover plate, and the fastener is connected to the lead bar through the hole.

[0012] Preferably, an inward recess is provided at the connection between the cover plate and the aluminum shell, and both ends of the cover plate are clamped in the recess.

[0013] The beneficial effects of the present invention are as follows: the length of the foil is reduced by winding, and after the foil is wound, the volume of the aluminum electrolytic capacitor is reduced. In addition, the thickness and general density of the electrolytic paper used in this patent are relatively small, and corrosion holes with larger apertures are provided on the foil to facilitate the penetration of the electrolyte, so that the capacitor can withstand the impact of large ripple currents while being small in size, reducing the possibility of breakdown and extending the service life of the capacitor. At the same time, multiple pairs of lead strips are provided in the electrolytic paper interlayer for shunting, further increasing the upper limit of the capacitor's ability to withstand large current ripples, and providing an anode foil at the cathode instead of the original cathode foil enables the capacitor to withstand reverse voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a structural diagram of a capacitor part of the utility model.

[0015] Figure 2 It is a top view of a shell part of the utility model.

[0016] Figure 3 It is a cross-sectional view of a large capacitor device of the present utility model.

[0017] 1. Electrolytic paper, 2. Anode foil, 3. Cathode foil, 4. Lead strip, 5. Cover plate, 6. Aluminum shell, 7. Casing, 8. Fasteners. DETAILED DESCRIPTION

[0018] The technical solution of the present invention will be further specifically described below through examples and in conjunction with the accompanying drawings. Example 1: In existing industrial processes, the current of a spot welder during welding can reach 50-600A. This current value is relatively large for existing spot welders, and the power-on frequency of the current in the spot welder needs to reach 11-15 times per minute. Therefore, the capacitor installed in the spot welder needs to meet the use conditions of low internal resistance and low temperature rise. At the same time, the spot welder will generate a reverse voltage during welding, and the existing capacitors do not have the ability to withstand ripples, and the capacitors often fail due to breakdown. In response to the above situation, a large capacitor device of this embodiment includes a capacitor part, such as Figure 1 As shown, the device comprises electrolytic paper 1 and foil sheets, which are divided into cathode foil 3 and anode foil 2. Both cathode foil 3 and anode foil 2 are placed on the electrolytic paper 1, with the electrolytic paper 1 with cathode foil 3 and the electrolytic paper 1 with anode foil 2 stacked crosswise. The cathode foil 3 and anode foil 2 are provided with a number of large-pore shallow-etched inorganic acid-treated etch holes. The foil sheets with etch holes have a thickness of 75-90μ, a specific capacitance of ≤0.25μF / cm², and a withstand voltage of ≥660V. After the stacking of the electrolytic paper 1, it is wound to form a roll-shaped capacitor section. The anode foil 2, which has large-pore shallow-etched etch holes, and the inorganic acid-treated aluminum foil have a thickness of 75-90μ and a specific capacitance of ≤0.25μF / cm². Macroporous, shallowly etched aluminum foil has a low specific capacitance. The large-diameter etched pores facilitate electrolyte penetration, reducing electrolyte loss and loss when the electrolytic paper 1 is soaked. The inorganically acidified anode foil 2 has a stable oxide film and low leakage current, thus achieving the technical effect of low temperature rise when made into a capacitor. Several lead bars 4 are inserted into the gaps of the rolled electrolytic paper 1. Because spot welding machines draw a particularly high current during the welding process, using multiple pairs of lead bars 4 can help shunt the current. For example, a 500V, 470μF, 50*80 capacitor typically uses two pairs of lead bars 4, but in this embodiment, four pairs are required. A 475V, 1000μF, 76*145 capacitor typically uses three pairs of lead bars 4, but in this embodiment, six pairs are used.

[0019] This embodiment also includes a low-voltage reverse aging process before forward aging. This aging charging method extends the service life of the capacitor and improves its reverse current ripple carrying capacity. Specifically, during charging, the capacitor is charged for two hours. For example, a 16V anode foil 2 is first charged at 16V for two hours before forward aging. In the structural design of existing aluminum electrolytic capacitors, the withstand voltage of the anode foil 2 is generally selected to be a high multiple of the operating voltage. To prevent the electrolytic paper 1 from easily breaking down, the general thickness of the electrolytic paper 1 is generally set thicker at conventional general density. This inevitably results in a larger space occupied by the electrolytic paper 1 after winding, resulting in a longer length of the anode foil 2, which in turn increases the number of windings of the anode foil 2, which in turn increases the volume and weight of the spot welding machine used with the capacitor, making the spot welding machine inconvenient to use. Therefore, in this embodiment, the thickness of the electrolytic paper 1 is selected to be lower than the general thickness and general density, that is, lower than the general thickness and general density of the electrolytic paper 1 corresponding to the operating voltage. The internal resistance of the capacitor part made according to the above structure is one-third of the original one. The conventional aluminum foil has fine pores, and it is difficult for the electrolyte to penetrate completely. The relative capacity will also be lower, and the loss and leakage current are large. The capacitor in this embodiment has a small internal resistance, high capacity, and small leakage current. It can withstand large ripple and reverse voltage and is suitable for large current charging and discharging.

[0020] like Figure 2 and Figure 3As shown, the large capacitor device, in addition to the capacitor portion, includes an anode foil 2, which serves as the anode and is corroded and energized to form an oxide film that serves as the working medium; a cathode foil 3, which serves as the cathode lead; an electrolytic paper 1, which stores electrolyte, separates the anode foil 2 from the cathode foil 3, and increases voltage resistance; a lead bar 4, which connects and leads the lead; and the electrolyte, which serves as the actual cathode and repairs the oxide film. The device also includes a body portion, with the capacitor portion located in the center of the housing. The housing includes a cover plate 5, which provides sealing and mounting functions; an aluminum shell 6, which protects and secures the core; and a sleeve 7, which includes PVC heat-shrink tubing and an insulating gasket, which provides insulation and enhances the appearance. A recessed opening is provided at the junction of the aluminum shell 6 and the cover plate 5, allowing the cover plate 5 to fit more tightly within the aluminum shell 6, further enhancing the seal of the cover plate 5 and ensuring more stable operation of the capacitor portion. Fasteners 8 are provided on the lead bar 4, extending outward from the connection to the cover plate 5, further enhancing the seal of the capacitor portion when placed in the center of the housing and improving the stability of the large capacitor device. Before actual capacitor use, the capacitor assembly described in this example must be fabricated. The fabrication process includes the following steps: 1. Foil cutting: Cut the capacitor paper, anode foil 2, cathode foil 3, and aluminum lead strips into specified sizes for use in the next process; 2. Winding: Rivet the lead strips 4 or wires onto the corresponding aluminum foils, and then roll the riveted anode and cathode foils 3 and electrolytic paper 1 into a capacitor core; 3. Impregnation: After the core is dried, impregnate it with an electrolyte of the corresponding operating voltage to serve as the cathode, repairing the oxide film; and 4. Assembly and sealing: The core and cover plate 5 are riveted or welded together. For lead production, the two leads of the core are inserted into the two holes of the lead plug and pressed tightly. The lead wires are then placed into the outer shell and sealed to form the capacitor. 5. Aging: Applying a DC voltage repairs the damaged oxide film on the aluminum foil surface. 6. Sleeve 7: Print the capacitor model and specifications on the PVC sleeve 7 and fit the sleeve 7 along with the gasket onto the capacitor. 7. Testing: Measure the three parameters of the capacitor, eliminate defective products, and ensure that the capacitor meets customer requirements. 8. Packaging: Place qualified products into a box and seal them. Once completed, the capacitor assembly is placed in a spot welder and powered on to operate normally.

[0021] The utility model provides a large capacitor device. The basic structure of an aluminum electrolytic capacitor is a foil-wound structure. It is made of an anode foil 2 that has been corroded and formed into an oxide film, a cathode foil 3 that has been corroded, and an electrolytic paper 1 in between. The core package is then wound into a core package, which is then impregnated with electrolyte, and then a cover plate 5 is riveted on and sealed in an aluminum shell 6. The length of the anode foil 2 of the utility model is reduced. After the winding is completed, the number of windings of the aluminum electrolytic capacitor can be reduced, thereby reducing the volume of the aluminum electrolytic capacitor. Compared with the prior art in which the electrolytic paper 1 uses electrolytic paper 1 of a universal thickness and universal density, the volume of the aluminum electrolytic capacitor formed after the winding is completed can be reduced. The breakdown rate of the aluminum electrolytic capacitor is reduced, and the oxidation time of the anode foil 2 during oxidation can be shortened, thereby improving efficiency and reducing costs.

[0022] Example 2: The large capacitor device in this embodiment is the same as that in the embodiment. A large capacitor device in this embodiment includes a capacitor part, such as Figure 1 As shown, the device comprises electrolytic paper 1 and foil sheets, which are divided into cathode foil 3 and anode foil 2. Both cathode foil 3 and anode foil 2 are placed on the electrolytic paper 1, with the electrolytic paper 1 with cathode foil 3 and the electrolytic paper 1 with anode foil 2 stacked crosswise. The cathode foil 3 and anode foil 2 are provided with a number of large-pore shallow-etched inorganic acid-treated etch holes. The foil sheets with etch holes have a thickness of 75-90μ, a specific capacitance of ≤0.25μF / cm², and a withstand voltage of ≥660V. After the stacking of the electrolytic paper 1, it is wound to form a roll-shaped capacitor section. The anode foil 2, which has large-pore shallow-etched etch holes, and the inorganic acid-treated aluminum foil have a thickness of 75-90μ and a specific capacitance of ≤0.25μF / cm². Macroporous, shallowly etched aluminum foil has a low specific capacitance. The large-diameter etched pores facilitate electrolyte penetration, reducing electrolyte loss and loss when the electrolytic paper 1 is soaked. The inorganically acidified anode foil 2 has a stable oxide film and low leakage current, thus achieving the technical effect of low temperature rise when made into a capacitor. Several lead bars 4 are inserted into the gaps of the rolled electrolytic paper 1. Because spot welding machines draw a particularly high current during the welding process, using multiple pairs of lead bars 4 can help shunt the current. For example, a 500V, 470μF, 50*80 capacitor typically uses two pairs of lead bars 4, but in this embodiment, four pairs are required. A 475V, 1000μF, 76*145 capacitor typically uses three pairs of lead bars 4, but in this embodiment, six pairs are used.

[0023] This embodiment also includes a low-voltage reverse aging process before forward aging. This aging charging method extends the service life of the capacitor and improves its reverse current ripple carrying capacity. Specifically, during charging, the capacitor is charged for two hours. For example, a 16V anode foil 2 is first charged at 16V for two hours before forward aging. In the structural design of existing aluminum electrolytic capacitors, the withstand voltage of the anode foil 2 is generally selected to be a high multiple of the operating voltage. To prevent the electrolytic paper 1 from easily breaking down, the general thickness of the electrolytic paper 1 is generally set thicker at conventional general density. This inevitably results in a larger space occupied by the electrolytic paper 1 after winding, resulting in a longer length of the anode foil 2, which in turn increases the number of windings of the anode foil 2, which in turn increases the volume and weight of the spot welding machine used with the capacitor, making the spot welding machine inconvenient to use. Therefore, in this embodiment, the thickness of the electrolytic paper 1 is selected to be lower than the general thickness and general density, that is, lower than the general thickness and general density of the electrolytic paper 1 corresponding to the operating voltage. The internal resistance of the capacitor part made according to the above structure is one-third of the original one. The conventional aluminum foil has fine pores, and it is difficult for the electrolyte to penetrate completely. The relative capacity will also be lower, and the loss and leakage current are large. The capacitor in this embodiment has a small internal resistance, high capacity, and small leakage current. It can withstand large ripple and reverse voltage and is suitable for large current charging and discharging.

[0024] like Figure 2 and Figure 3As shown, the large capacitor device, in addition to the capacitor portion, includes an anode foil 2, which serves as the anode and is corroded and energized to form an oxide film that serves as the working medium; a cathode foil 3, which serves as the cathode lead; an electrolytic paper 1, which stores electrolyte, separates the anode foil 2 from the cathode foil 3, and increases voltage resistance; a lead bar 4, which connects and leads the lead; and the electrolyte, which serves as the actual cathode and repairs the oxide film. The device also includes a body portion, with the capacitor portion located in the center of the housing. The housing includes a cover plate 5, which provides sealing and mounting functions; an aluminum shell 6, which protects and secures the core; and a sleeve 7, which includes PVC heat-shrink tubing and an insulating gasket, which provides insulation and enhances the appearance. A recessed opening is provided at the junction of the aluminum shell 6 and the cover plate 5, allowing the cover plate 5 to fit more tightly within the aluminum shell 6, further enhancing the seal of the cover plate 5 and ensuring more stable operation of the capacitor portion. Fasteners 8 are provided on the lead bar 4, extending outward from the connection to the cover plate 5, further enhancing the seal of the capacitor portion when placed in the center of the housing and improving the stability of the large capacitor device. Before actual capacitor use, the capacitor assembly described in this example must be fabricated. The fabrication process includes the following steps: 1. Foil cutting: Cut the capacitor paper, anode foil 2, cathode foil 3, and aluminum lead strips into specified sizes for use in the next process; 2. Winding: Rivet the lead strips 4 or wires onto the corresponding aluminum foils, and then roll the riveted anode and cathode foils 3 and electrolytic paper 1 into a capacitor core; 3. Impregnation: After the core is dried, impregnate it with an electrolyte of the corresponding operating voltage to serve as the cathode, repairing the oxide film; and 4. Assembly and sealing: The core and cover plate 5 are riveted or welded together. For lead production, the two leads of the core are inserted into the two holes of the lead plug and pressed tightly. The lead wires are then placed into the outer shell and sealed to form the capacitor. 5. Aging: Applying a DC voltage repairs the damaged oxide film on the aluminum foil surface. 6. Sleeve 7: Print the capacitor model and specifications on the PVC sleeve 7 and fit the sleeve 7 along with the gasket onto the capacitor. 7. Testing: Measure the three parameters of the capacitor, eliminate defective products, and ensure that the capacitor meets customer requirements. 8. Packaging: Place qualified products into a box and seal them. Once completed, the capacitor assembly is placed in a spot welder and powered on to operate normally.

[0025] In addition, in this embodiment, a low-voltage 16V-50V anode foil 2 replaces the cathode foil 3 at the cathode. The large capacitor device in this embodiment requires low-voltage reverse aging before undergoing forward aging. After the cathode foil 3 is replaced with a low-voltage 16V-50V anode foil 2, the maximum voltage applied to the cathode is only about 7V. Due to the excessive ripple current, it is insufficient to withstand the reverse voltage, so the low-voltage anode foil 2 is used instead. After the replacement is completed, the length of the anode foil 2 of the utility model is reduced. After winding is completed, the number of windings of the aluminum electrolytic capacitor can be reduced, thereby reducing the volume of the aluminum electrolytic capacitor. Compared with the prior art in which the electrolytic paper 1 uses electrolytic paper 1 of a universal thickness and universal density, the volume of the aluminum electrolytic capacitor formed after winding is reduced. The breakdown rate of the aluminum electrolytic capacitor is reduced, and the oxidation time of the anode foil 2 can be shortened during oxidation, thereby improving efficiency and reducing costs. At the same time, the arrangement of replacing the cathode foil 3 with the anode foil 2 can increase the capacitor's ripple current carrying capacity, thereby improving the reverse voltage carrying capacity and extending the service life of the capacitor device.

Claims

1. A large capacitor device, characterized in that The invention comprises a shell part and a capacitor part, wherein the capacitor part is arranged at the center of the shell part, and the capacitor part comprises electrolytic paper and foil, wherein the foil covers the surface of the electrolytic paper, and the electrolytic paper and the foil are stacked alternately, and the foil is provided with corrosion holes with a cross-sectional diameter sufficient to allow the electrolyte to effectively penetrate.

2. A large capacitor device according to claim 1, characterized in that: The capacitor part includes a plurality of wound electrolytic papers, and the foils include cathode foils and anode foils, both of which are arranged on the electrolytic paper, and the cathode foils arranged on the electrolytic paper and the anode foils arranged on the electrolytic paper are alternately stacked.

3. A large capacitor device according to any one of claims 1 or 2, characterized in that: The shell part includes an aluminum shell and a sleeve. The aluminum shell is arranged inside the sleeve. A cover plate is arranged inside the aluminum shell. The cover plate and the aluminum shell are connected to form an inner cavity. The capacitor part is arranged in the inner cavity.

4. A large capacitor device according to claim 2, characterized in that: A lead bar is provided between the wound electrolytic papers. The lead bar is in a long and flat strip shape, and one end of the lead bar extends outward from the gap between the electrolytic papers.

5. A large capacitor device according to claim 4, characterized in that: The capacitor part and the shell part are connected via a lead bar, and the lead bar is connected to the bottom end of the cover plate.

6. A large capacitor device according to claim 3, characterized in that: A fastener is provided at the center of the top end of the shell, and the cross section of the sleeve is circular.

7. A large capacitor device according to claim 6, characterized in that: A hole is provided in the center of the cover plate, and the fastener is arranged on the top of the cover plate. The fastener is connected to the lead bar through the hole.

8. A large capacitor device according to claim 7, characterized in that: An inward recess is provided at the connection between the cover plate and the aluminum shell, and both ends of the cover plate are clamped in the recess.

9. A large capacitor device according to claim 4, characterized in that: The guide strips are arranged between the fasteners.

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