Aluminum alloy miniature tubular fuse

Abstract

The invention relates to an aluminum alloy miniature tubular fuse. The invention provides a high-capacity miniature tubular fuse. The fuse includes a cylindrical housing, a fusible wire, and first and second deep-drawn ferrules made of an aluminum alloy. Aluminum is plated with nickel. The ferrule includes a side wall and an end wall. The sidewall surrounds the first end or the second end of the housing and has a thickness of about 0.50 mm or less. The end wall includes a projection extending toward an interior of the housing and has a thickness greater than a thickness of the side wall.

Description

[0001] This application is a divisional application of the Chinese invention patent application with the application date of April 16, 2020, application number 202010304090.9, and invention name “Aluminum Alloy Miniature Tube Fuse”. Background Art

[0002] The field of the present disclosure relates generally to electronic fuses, and more particularly to miniature cartridge fuses having aluminum ferrules.

[0003] Fuses are widely used overcurrent protection devices for disconnecting electrical circuits and preventing associated components from being damaged by overcurrent in electrical systems. Because fuses, especially miniature cartridge fuses, are high-capacity electronic components, even incremental cost reductions in fuse manufacturing without sacrificing performance are of great value. Improvements are desirable. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Non-limiting and non-exhaustive embodiments are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various figures unless otherwise specified.

[0005] Figure 1A is a perspective view of an exemplary fuse.

[0006] Figure 1B yes Figure 1A A cross-sectional view of the fuse is shown.

[0007] Figure 2A is another exemplary fuse.

[0008] Figure 2B is yet another exemplary fuse.

[0009] Figure 2C is yet another exemplary fuse.

[0010] Figure 3A is a graph of the cold resistance of an exemplary fuse having a ferrule made of an aluminum alloy that is not plated.

[0011] Figure 3B is a graph of the cold resistance of an exemplary fuse having a ferrule made of an aluminum alloy that is plated.

[0012] Figure 4 Show Figure 1B Bushing interface forces for the fuse shown.

[0013] Figure 5 is a graph showing the peak temperature of fusible links in two fuses, one of which has a ferrule made of brass and the other of which has a ferrule made of an aluminum alloy.

[0014] Fig. 6A yes Figure 1B An enlarged view of the ferrule of the fuse is shown.

[0015] Figure 6B yes Figure 1B Another exemplary ferrule of a fuse is shown.

[0016] Figure 6C yes Figure 1B Yet another exemplary ferrule of a fuse is shown.

[0017] Fig.6D yes Figure 1B Yet another exemplary ferrule of a fuse is shown.

[0018] Figure 7 is a flow chart illustrating an exemplary method of manufacturing a fuse. DETAILED DESCRIPTION

[0019] Fuses are sacrificial components that are widely used to protect other components in electrical systems. In the UK, fuses are often integrated into the plugs of electrical devices. These types of fuses are sometimes called miniature cartridge fuses.

[0020] Fuse components other than the housing and filler (if any) are typically made of copper or copper alloys. Although aluminum is more than three times cheaper than copper, aluminum is not typically used in miniature tube fuses, especially in the ferrules of miniature fuses. Instead, aluminum has been considered generally unsuitable for use in miniature fuses because it is significantly weaker than copper or copper alloys, which raises concerns about whether aluminum components can reliably withstand the expected operating conditions of the fuse in use, including, for example, whether the aluminum ferrule can effectively withstand the high pressure generated inside the housing and remain in place after repeated temperature and pressure changes caused by current or arc discharge during a short circuit event, and whether operational reliability can be ensured.

[0021] Contrary to long-held beliefs in the art, the inventive fuse disclosed herein overcomes the limitations of aluminum while ensuring that circuit protection and performance are not compromised, thereby achieving the desired cost reduction in miniature tube fuse manufacturing. Lower cost components such as ferrules and / or fusible wires and / or metal rings made from aluminum alloys are employed to reduce the amount of traditional copper or copper alloys in fuse manufacturing. In order to meet the unique needs and challenges of miniature tube fuse design, suitable types of aluminum alloys are strategically evaluated and selected based on their specific properties and characteristics, and with appropriate structural modifications to certain components and enhanced manufacturing methods, fuse component designs and assemblies that reliably meet the performance specifications of miniature fuses at reduced manufacturing costs can be ensured.

[0022] In a first aspect, the aluminum alloy fuse of the present invention comprises a ferrule, fusible wire and / or metal ring made of an aluminum alloy plated with nickel by chemical plating. Chemical plating allows reliable coating of aluminum or aluminum alloy with nickel to prevent oxidation that might otherwise occur. Therefore, a fuse with consistent resistance is possible so that the resistance of the fuse does not increase undesirably over time.

[0023] In a second aspect, the aluminum alloy fuse of the present invention is made of an aluminum alloy that is strategically selected based on its strength and melting point so that the fuse can withstand the internal pressure and temperature changes typically caused by arcing during a short circuit event when the fuse is operating. The fuse is also designed to remain intact and have a high unsealing force on its ferrule required to separate the ferrule. The low diameter tolerance between the ferrule and the housing increases the friction between them, thereby increasing the required unsealing force. Therefore, the fuse is cheaper, but still suitable for the desired performance and function.

[0024] In a third aspect, the aluminum alloy time delay fuse of the present invention includes an aluminum alloy strategically selected based on its thermal conductivity. The aluminum alloy having a thermal conductivity close to that of brass allows the fusible wire to heat up and reach a melting temperature when a current higher than the rated value passes through the fuse to maintain the function of a conventional time delay fuse after a certain period of time.

[0025] In a fourth aspect, a method for manufacturing a high capacity miniature tube fuse is achieved. The method includes providing a cylindrical housing and providing an aluminum alloy sheet. The method also includes: constructing a ferrule from the aluminum alloy sheet by a deep drawing process; plating the ferrule with nickel; inserting a fusible wire into the interior of the housing; and inserting a first end or a second end of the fusible wire through the metal ring. The method also includes: detaching the first end or the second end of the fusible wire from the body of the fusible wire, and inserting the first end or the second end of the fuse into the internal receiver of the ferrule so that the first end or the second end of the fusible wire remains between a portion of the metal ring and the end wall of the ferrule. The mechanical and electrical connection is completed by fixing the ferrule to the housing by clamping the ferrule around the first end or the second end of the housing. The manufacturing method is efficient and provides a less expensive fuse that replaces copper with an aluminum alloy but still meets the desired specifications and performance.

[0026] Aluminum alloy fuses and methods of manufacture satisfy a long-standing and unfulfilled need in the art to reduce the cost of fuses by strategically selecting and designing the fuses based on desired performance and functionality to overcome the performance differences and limitations of aluminum alloys and copper or copper alloys. In contemplated embodiments, the aluminum alloy fuses of the present invention are significantly less expensive than conventional fuses made of copper or copper alloys.

[0027] Although described in the context of a miniature cartridge fuse, the inventive concepts herein are not necessarily limited to this particular type of fuse. Accordingly, the following description is provided for purposes of illustration and not limitation.

[0028] Figure 1A An exemplary fuse 100 is shown. The fuse 100 includes a housing 102, a first ferrule 104, and a second ferrule 106. The housing may also be referred to as a fuse body or tube. The ferrules may be referred to as terminals or end caps. The first ferrule 104 and the second ferrule 106 are coupled to the housing 102 at a first end 108 or a second end 110 of the housing 102. The first ferrule 104 and the second ferrule 106 surround and cover the first end 108 and the second end 110 of the housing 102, respectively.

[0029] In an exemplary embodiment, housing 102 is cylindrical. A fuse having a cylindrical housing may be referred to as a cartridge fuse. Alternatively, housing 102 is any other shape that enables the housing to function as described herein, including but not limited to oval, square, rectangular, or a combination thereof. Housing 102 may be made of glass, ceramic, or other non-conductive material.

[0030] In an exemplary embodiment, the ferrules 104, 106 are made of an aluminum alloy. The aluminum alloy of the ferrules 104, 106 is selected so that the ferrules 104, 106 remain on the housing 102 after repeated expansion due to heat and their electrical properties do not deteriorate over time. The ferrules 104, 106 can be mass-produced by a deep drawing process.

[0031] Figure 1B A cross-sectional view of the fuse 100 is shown, and Figure 1A Similar reference numerals used in Figure 1B The fuse 100 also includes a fusible wire 112. In some embodiments, the fuse 100 includes a metal ring 114.

[0032] In an exemplary embodiment, the ferrules 104, 106 include a sidewall 116 and an end wall 118. The end wall 118 extends from the sidewall 116 and closes the first end 108 or the second end 110 of the housing 102. The end wall 118 may include a protrusion 120. The protrusion 120 extends inwardly toward the housing 102 and defines an interior surface 122 of the end wall 118. The protrusion 120 may be frustoconical. The end wall 118 and the sidewall 116 define an internal receptacle 124.

[0033] In an exemplary embodiment, the fusible wire 112 is a wire that fails structurally when the current flowing through the wire is greater than a threshold value, and opens the circuit to protect other electronic components in the circuit. The fusible wire 112 is made of zinc, copper, silver, aluminum or other metals or alloys to provide such characteristics. The fusible wire 112 is positioned inside the housing 102 and is electrically connected to the first ferrule 104 and the second ferrule 106 at the first end 130 and the second end 132 of the fusible wire 112, respectively.

[0034] In an exemplary embodiment, the metal ring 114 includes an orifice 126. The orifice 126 can be disposed at the center of the metal ring 114. The metal ring 114 can also include a protrusion 127 that arches toward the interior of the housing 102. The orifice 126 can be positioned in the protrusion 127. The protrusion 127 has a mating surface with the protrusion 120 of the end wall 118 of the first ring 104 or the second ring 106. The metal ring 114 is made of aluminum, copper, an aluminum alloy, brass or other copper alloys. Alternatively, the metal ring 114 is made of other materials that enable the metal ring to function as described herein. The metal ring 114 can be mass-produced by a deep drawing process.

[0035] The fuse 100 further includes a filler 128 filling the interior of the housing 102. The filler 128 is used to contain arc energy during a short circuit event. The filler 128 may be made of silica sand or a mixture of silica sand and other materials such as resin, gypsum or zeolite.

[0036] To manufacture the fuse 100, the first end 130 or the second end 132 of the fusible wire 112 is inserted through the aperture 126 of the eyelet 114. In some embodiments, the first end 130 or the second end 132 is disengaged from the body 134 of the fusible wire 112 and is directed toward the wall 136 of the housing 102. The fusible wire 112 can be disposed diagonally within the interior of the housing 102. The eyelet 114 can be disposed adjacent to the interior surface 122 of the end wall 118. In some embodiments, the first end 130 and / or the second end 132 of the fusible wire 112 and / or the edge 138 of the eyelet 114 can be wedged between the end wall 118 of the ferrule 104, 106 and the first end 108 and / or the second end 110 of the housing 102. In one embodiment, the first end 130 and / or the second end 132 of the fusible wire 112 can be wedged between the protrusion 120 and the mating surfaces of the eyelet 114. The housing 102 is inserted into the internal receptacle 124 formed by the ferrules 104, 106. In some embodiments, the ferrules 104, 106 are secured to the housing 102 by clamping the side walls 116 to the walls 136 of the housing 102.

[0037] In operation, the fusible link 112 is electrically connected to the ferrules 104, 106. If a metal ring 114 is used in the fuse 100, the metal ring 114 is also electrically connected to the fusible link 112.

[0038] Fuse 100 may be a high capacity miniature cartridge fuse. As used herein, "high capacity" refers to a high breaking capacity as defined by the standards of the International Electrotechnical Commission (IEC), such as, for example, an IEC 60127 fuse with a maximum breaking capacity of up to 1500 amperes or a BS 1362 fuse with a maximum breaking capacity of up to 6000 amperes. The physical dimensions of the miniature fuse are relatively small, for example, 5 mm×20 mm or 6.3 mm×32 mm. In some embodiments, the sidewalls 116 of the ferrules 104, 106 have a thickness of 0.50 mm or less.

[0039] Figure 2A Another exemplary fuse 200 is shown, and Figure 1A and Figure 1B Like reference numerals in FIG. 2 are used to identify like components shown in FIG. 2. The fusible wire 202 is held in place by the metal ring 114. Figure 1B In contrast, the first end 204 of the fusible wire 202 is directly attached to the protrusion 120 of the collar 104, and the second end 206 of the fusible wire 202 does not extend all the way along the mating surface between the eyelet 114 and the protrusion 120 of the end wall 118, such that the end 206 is disposed below the eyelet 114 but not between the end 110 of the housing 102 and the end wall 118 of the collar 106.

[0040] Figure 2B Still another exemplary fuse 1200 is shown, and Figure 1A and Figure 1B Similar reference numerals in the Figure 2B Similar parts as shown. Figure 1B In contrast, fuse 1200 includes more than one fusible wire 210. The end 212 of the fusible wire 210 may be as shown in FIG. Figure 2B As shown, they are disposed on the same side of the housing 102, or they may be disposed as shown. Figure 1B 106. The ends 212 are shown disposed diagonally inside the housing 102. Alternatively, the ends 212 may be disposed inside the housing 102 in any other configuration that enables the fusible wire to function as described herein, for example, the ends of the fusible wire may be placed adjacent to any position on the ferrules 104, 106. In addition, the fuse 1200 may have three or more fusible wires 210. With a greater number of fusible wires 210, the fuse 1200 has a higher current carrying capacity than the fuse 100 having a single fusible wire 112.

[0041] Figure 2C Yet another exemplary fuse 1300 is shown, and Figure 1A and Figure 1B Similar reference numerals in the Figure 2C Similar parts as shown. Figure 1B In contrast, fuse 1300 does not include metal ring 114. Fusible wire 220 of fuse 1300 is directly electrically connected to ferrules 104, 106 via methods such as welding end 222 to ferrules 104, 106 or welding the end to protrusion 120 if ferrules 104, 106 include protrusion 120. In addition to fusible wire 112, 202, 210, 220, the fusible element of fuse 100, 200, 1200, 1300 can be other types of fusible elements that enable the fuse to function as described herein.

[0042] In addition to the ferrules 104, 106, the fusible wire 112, 202 and / or the metal ring 114 may be made of an aluminum alloy. Aluminum alloys have significantly different properties compared to copper or copper alloys. Table 1 below lists the comparison.

[0043]

[0044] The type of aluminum alloy and the design of the fuse are strategically determined to meet the requirements of a specific application and power system. After selecting the type of aluminum alloy for the fuse 100, 200, strength (such as tensile strength) is considered. and yield strength ) and melting point. Other properties such as elongation, electrical resistivity and thermal conductivity were also considered.

[0045] In fuses 100, 200, the type of aluminum alloy selected has a high enough strength to hold ferrule 104, 106 to housing 102 and, if an aluminum alloy is used for eyelet 114, to hold fusible wire 112, 202 underneath. AL 1100 may be too soft for some applications. In some embodiments, the aluminum alloy used for fuses 100, 200 has a tensile strength of about 138 MPa or more. In some embodiments, the aluminum alloy used for fuses 100, 200 has a yield strength of about 117 MPa or higher. In one embodiment, AL 5052 alloy is used for the ferrules 104 , 106 and the eyelet 114 .

[0046] When the melting point of an aluminum alloy is used to select the type of aluminum alloy, the melting point of the selected aluminum alloy should be high enough to allow the ferrules 104, 106, and the eyelet 114 (if an aluminum alloy is used for the eyelet 114), to withstand the heat generated by the current flow and remain intact to contain the arc energy within the interior of the fuse 100, 200. In some embodiments, the aluminum alloy used for the fuse 100, 200 has a melting point of about 590°C or higher.

[0047] When high interrupting capacity is desired, the type of aluminum alloy is selected to have a relatively high thermal conductivity and melting temperature. In some embodiments, AL 5005 alloy is used to achieve high interrupting capacity for its relatively high melting point and relatively high thermal conductivity.

[0048] When using a deep drawing process to manufacture the ferrules 104, 106 and eyelet 114 from an aluminum alloy, the selected aluminum alloy has a sufficiently high elongation required for the manufacturing process to manufacture the designed shaped parts without breaking. The aluminum alloys listed in Table 1 have elongations sufficient to withstand the deep drawing process.

[0049] Surface oxidation of aluminum or aluminum alloys tends to be rapid. Therefore, the contact resistance of the fusible wire 112, 202 increases over time and causes a decrease in the current through the ferrule 104, 106, which causes the fuse 100, 200 to fail. In an exemplary embodiment, nickel plating is used to plate the aluminum alloy. Copper or copper alloys can also be plated with nickel. Conventional plating methods do not work for plating aluminum or aluminum alloys with nickel, where the nickel plated on the aluminum or aluminum alloy tends to flake off or not stick to the surface of the aluminum or aluminum alloy. In an exemplary embodiment, chemical nickel plating is used. Figure 3A and Figure 3B The aluminum alloy used without nickel plating ( Figure 3A ) and the resistance of the fuse 100 having an aluminum alloy ferrule and an aluminum alloy metal ring and having an aluminum alloy used for nickel plating ( Figure 3B ) when the aluminum alloy ring and aluminum alloy metal ring fuse 100 resistance comparison. Aluminum alloy 5052 is used for Figure 3A and Figure 3B In the example shown. Since the resistance is temperature dependent, the cold resistance is measured at room temperature, where the current is less than 10% of the rated current of the fuse. Without plating, the resistance can triple after 2000 hours, which is less than three months (see Figure 3A ). However, in the case of plating, the resistance is stabilized and its variation is kept less than 6% (see Figure 3B ).

[0050] Bushing interface forces were examined in the design of the fuses 100, 200 when changing from copper or copper alloys to aluminum alloys as the material used to make the fuses 100, 200. Figure 4The effect of the bushing interface force on the ferrules 104, 106 and the metal ring 114 of the fuse 100 is shown. Figure 4 The fuse 100 is shown, but the discussion below is similarly applicable to the fuses 200, 1200, 1300. The bushing interface force is the force at the interface between the ferrules 104, 106 and the housing 102, which prevents the ferrules 104, 106 from being separated from the housing 102. During a high current short circuit event or interrupting capacity test, the disconnection of the fusible wire is associated with a sudden release of energy, which causes an arc to be generated inside the fuse. Due to the arc discharge, high voltage is generated inside the fuse, and the fuse housing and ferrule need to be able to withstand this high voltage and remain in place. After the short circuit event, the housing should not have visible defects. Similarly, the ferrule should not have any visible defects, including perceptible movement or separation from the housing when the fuse is operated. In order to prevent the movement or separation of the ferrule, the ferrule is constrained to the housing 102. The interface force between the ferrules 104, 106 and the housing 102 provides a restraining force when there is no additional restraining feature in the fuse design.

[0051] The interface force is generated by the friction between the housing 102 and the ferrules 104, 106, that is, the friction force F t Friction force F t Equal to the coefficient of friction and the normal force F n The product of the normal force F n Depends on the elasticity (Young's modulus E) and yield strength of the material Because, for aluminum alloy, Young's modulus E is about 30% smaller than that of copper alloy, and the yield strength About 30% to 36% smaller than copper alloys (see Table 1), so the interface tolerance is a consideration in designing the ferrule in addition to the aluminum alloy selection and the ferrule thickness design. The interface tolerance is the difference between the inner diameter 402 of the internal receiver 124 formed by the ferrule 104, 106 and the outer diameter 404 of the housing 102. In some embodiments, the fuse 100, 200 is designed to have a friction force of about 150 Newtons or more. In one embodiment, the inner diameter 402 of the internal receiver 124 is about 20μm or less greater than the outer diameter 404 of the housing 102. The diameters 402, 404 are measured at the area of ​​the side wall 116 of the ferrule 104, 106 or the area of ​​the wall 136 of the housing 102, where the side wall 116 and the wall 136 are in contact with each other. In some embodiments, AL 5005 H32 aluminum alloy is used for the ferrules 104, 106.

[0052] During the normal service life of the fuse, the fuse is subjected to constant temperature changes, and the internal pressure exerted on the end of the fusible wire causes the ferrule to move axially relative to the fuse housing. In some embodiments, the strength provided by the aluminum alloy metal ring may not be sufficient to provide stable contact resistance between the fusible wire 112, 202 and the ferrule 104, 106 after such temperature changes or internal pressure shocks. Brass metal rings or metal rings made of copper or other copper alloys can be used to handle the internal pressure and keep the resistance stable.

[0053] In a time delay fuse, the fuse is designed to allow a current higher than the fuse rating to flow for a short period of time without opening the fuse. Time delay fuses can be used in devices such as motors that draw more current than normal for a short period of time to allow the device to get up to speed. However, if a higher than rated current is conducted for a long period of time, the fuse opens due to the heat caused by the current.

[0054] Figure 5 Curves of simulated fusible wire temperature are shown for a brass S505 fuse with a brass ferrule (shown as curve 502) and an AL S505 fuse with a ferrule made of AL5052 aluminum alloy (shown as curve 504). The S505 fuse is a time delay fuse in which its fusible wire is soldered to the ferrule. The insert shows the cold resistance of the brass S505 fuse and the AL S505 fuse for simulation. The fusible wires of the brass S505 fuse and the AL S505 fuse are made of the same material. The resistance from the fusible wire dominates the resistance of the fuse, and therefore, the resistance of the two fuses is almost the same. When a current higher than the rated current passes through the brass S505 fuse, the temperature of the fuse rises to the melting temperature of the solder and the fuse opens (see curve 502). In contrast, the temperature of the fusible wire of the AL S505 fuse initially rises, but then reaches a plateau after 40 seconds (see curve 504). The AL S505 fuse never opens. After designing a time delay fuse using an aluminum alloy, an aluminum alloy with high resistivity and low thermal conductivity is selected to maintain time-current performance under overload conditions. In some embodiments, AL 5154 is selected. With its thermal conductivity of 125 W / mK, it is close to the thermal conductivity of the brass material of 116 W / mK, so the ferrule is heated to the melting temperature and the fuse maintains its function as a time delay fuse.

[0055] Fig. 6A An enlarged view of the ferrules 104, 106 is shown. The ferrules 104, 106 include a protrusion 120. The thickness T of the end wall 118 2 Greater than the thickness T of the side wall 116 1 .Thickness T 2The thickness T is measured at a location of the end wall 118 other than the projection 120. In one embodiment, the thickness T 1 is about 0.325 mm, and the thickness T 2 It is about 0.55mm.

[0056] FIG. 6B to FIG. 6D Other exemplary embodiments of ferrules 602, 604, 606 are shown. Ferrules 602, 604, 606 may be used on fuses 100, 200 in place of ferrules 104, 106. Ferrule 602 (shown in Figure 6B ) are similar to the ferrules 104, 106 (shown in Fig. 6A ), the difference is that for the ring 602, the thickness T of the end wall 618 2 Slightly greater than or approximately equal to the thickness T of the sidewall 116 1 .exist FIG. 6B to FIG. 6D The thickness T of the end walls 617, 618, 619 is 2 Measured at locations other than protrusions 120, 620, 621. In one embodiment, for the ferrule 602, the thickness T 1 is about 0.325 mm, and the thickness T 2 The ferrules 604, 606 also have end walls 617, 619 with a thickness T greater than the side wall 116. 1 Thickness T 2 In one embodiment, for the ferrules 604, 606, the thickness T of the sidewall 116 is 1 is about 0.325 mm, and for the ferrule 604, the thickness T of the end wall 617 is 2 is approximately 0.58 mm, and for the ferrule 606, the thickness is approximately 0.36 mm.

[0057] Compared to the ferrules 104, 106, the ferrules 604, 606 have projections 620, 621 of different configurations (see Figure 6C and Fig.6D ). The projections 620, 621 include a recess 622 at the outer surface 624 of the end walls 617, 619. Solder may be deposited in the recess 622 to enhance electrical contact between the fuse 100, 200 and a circuit component or circuit board to which the fuse 100, 200 is connected. The thickness T of the projections 620, 621 is 3 Greater than the thickness T of the end wall 118 at locations other than the protrusions 620 and 621 2 In one embodiment, the thickness T of the protrusion 120 is 3 is about 1.6 mm (shown in Fig. 6A and Figure 6B The thickness T of the protrusion 620 is 3is about 0.61 mm (shown in Figure 6C The thickness T of the protrusion 621 is 3 is about 0.4 mm (shown in Fig.6D ). The projection 120, 620 has an end wall that is thicker than the rest of the end wall 118, 617, 618, 619, which helps contain heat from the fusible wire 112, 202 when the projection 120, 620 directly contacts the fusible wire 112, 202. In some embodiments, the projection 120, 620 includes a relatively flat top surface 626. The relatively flat top surface 626 allows for good contact between the fusible wire 202 and the end wall 118, 617, 618 when the fusible wire 202 is directly welded to the end wall 118, 617, 618.

[0058] Figure 7 A method of manufacturing a high capacity miniature cartridge fuse such as fuses 100 and 200 (shown in Figure 1A 2 ). The method 700 includes providing 702 a cylindrical housing. The method 700 also includes providing 704 an aluminum alloy sheet. The aluminum alloy sheet may be applied with a first heat treatment to improve the properties of the metal, for example, to increase the strength of the metal. The method 700 also includes constructing 706 a ferrule from the aluminum alloy sheet by a drawing process. The drawing process may be a deep drawing process. The method 700 also includes plating 707 the ferrule with nickel. A second heat treatment, such as annealing, may be applied to the ferrule to improve the properties of the ferrule, for example, to increase the strength of the ferrule. In addition, the method 700 includes inserting 708 a fusible wire into the interior of the housing. In addition, the method 700 includes inserting 710 a first end or a second end of the fusible wire through the metal ring. The method 700 also includes detaching 712 the first end or the second end of the fusible wire from the body of the fusible wire. The method 700 also includes inserting 714 the first end or the second end of the housing into the internal receptacle of the ferrule such that the first end or the second end of the fusible wire is retained between a portion of the metal ring and an end wall of the ferrule. Additionally, the method 700 includes securing 716 the ferrule to the housing by clamping the ferrule around the first end or the second end of the housing.

[0059] Various embodiments of fuses are described herein, including copper or copper alloy components replaced with aluminum alloy components having properties suitable for the performance and specifications of the fuse, thereby significantly reducing the manufacturing cost of the fuse. Plating the aluminum alloy with nickel reduces or eliminates oxidation of the aluminum alloy, thereby allowing the cold resistance of the fuse to remain unchanged or change little over time, so that the fuse has reliable performance. In addition, embodiments of the system and method provide aluminum alloy fuses that can withstand constant temperature changes and pressure shocks. For example, the tolerance between the inner diameter of the internal receiver formed by the ferrule and the outer diameter of the fuse housing is close, so that the interface force between the ferrule and the fuse housing is sufficient to allow the ferrule to remain in place through the service life of the fuse.

[0060] Although exemplary embodiments of components, assemblies, and systems are described, variations of the components, assemblies, and systems may achieve similar advantages and effects. Specifically, the shapes and geometries of the components and assemblies and the relative positions of the components in the assemblies may differ from those described and depicted without departing from the inventive concepts described. Additionally, in certain embodiments, certain components of the assemblies may be omitted to accommodate the needs of a particular type of fuse or a particular installation while still providing the performance and functionality required of the fuse.

[0061] It is now believed that the benefits and advantages of the inventive concepts have been fully demonstrated with respect to the disclosed exemplary embodiments.

[0062] An embodiment of a high-capacity miniature tube fuse has been disclosed. The fuse includes: a cylindrical housing having opposite first and second ends; a fusible wire, the fusible wire being positioned inside the housing and including opposite first and second ends; and a first deep-drawn ferrule and a second deep-drawn ferrule made of an aluminum alloy. The first ferrule and the second ferrule are respectively attached to the first end and the second end of the housing and electrically connected to the corresponding first end and the corresponding second end of the fusible wire, and the aluminum alloy is plated with nickel. Each of the first ferrule and the second ferrule includes a side wall and an end wall. The side wall surrounds the first end or the second end of the housing, wherein the side wall has a thickness of about 0.50 mm or less. The end wall extends from the side wall and closes the first end or the second end of the housing, wherein the end wall includes a protrusion extending toward the interior of the housing and defining an inner surface of the end wall, and the end wall has a thickness greater than the thickness of the side wall. The side wall and the end wall define an internal receptacle sized to receive the first end or the second end of the housing.

[0063] Optionally, the nickel plating may be chemical nickel plating. The aluminum alloy may have a tensile strength of about 138 MPa or more. The aluminum alloy may have a yield strength of about 117 MPa or more. The aluminum alloy may have a melting point of about 590°C or more. The friction between the side wall of the first ferrule or the second ferrule and the outer shell may be about 150 Newtons or more. The inner diameter of the internal receiver may be about 20µm or less greater than the outer diameter of the outer shell. The fuse may include two or more fusible wires. The fuse may also include a metal ring extending adjacent to the inner surface of the end wall of the first ferrule or the second ferrule. The fusible wire may extend through the metal ring and be retained between a portion of the metal ring and the end wall of the first ferrule or the second ferrule. The fuse may be configured as a time delay fuse, and the aluminum alloy may have a thermal conductivity of about 125 W / m·K or less and a thermal conductivity of about 5.32×10 -6 Resistivity of Ω-cm or higher.

[0064] An embodiment of a method for manufacturing a high capacity miniature tube fuse has also been disclosed. The method includes: providing a cylindrical housing, wherein the housing includes an opposing first end and a second end; and providing an aluminum alloy sheet. The method also includes constructing a ferrule from the aluminum alloy sheet by a deep drawing process. The ferrule includes a side wall and an end wall extending from the side wall. The side wall and the end wall define an internal receiver, and the internal receiver is sized to receive the first end or the second end of the housing. The side wall has a thickness of about 0.50 mm or less. The end wall includes a protrusion extending from the end wall in the same direction as the side wall and defining an inner surface of the end wall, and the end wall has a thickness greater than the thickness of the side wall. The method also includes plating the ferrule with nickel. The method also includes inserting a fusible wire into the interior of the housing, wherein the fusible wire includes an opposing first end and a second end. In addition, the method includes inserting the first end or the second end of the fusible wire through a metal ring. The method also includes detaching the first end or the second end of the fusible wire from the body of the fusible wire. The method also includes inserting the first end or the second end of the housing of the fuse into the internal receptacle of the ferrule so that the first end or the second end of the fusible wire is retained between a portion of the metal ring and the end wall of the ferrule. The method also includes securing the ferrule to the housing by clamping the ferrule around the first end or the second end of the housing.

[0065] Optionally, in the method of manufacturing a high-capacity miniature tube fuse, the nickel plating may be chemical nickel plating. The aluminum alloy may have a tensile strength of about 138 MPa or more. The aluminum alloy may have a yield strength of about 117 MPa or more. The aluminum alloy may have a melting point of about 590°C or more. The friction between the side wall of the ferrule and the outer shell may be about 150 Newtons or more. The inner diameter of the internal receiver may be about 20 µm or less greater than the outer diameter of the outer shell. The end wall may include a recessed portion in the outer surface of the end wall. The thickness of the protrusion may be greater than the thickness of the end wall at a position other than the protrusion. Providing an aluminum alloy sheet may also include applying a first heat treatment to the aluminum alloy sheet. The method may also include applying a second heat treatment to the ferrule. The fuse may be configured as a time delay fuse, and the aluminum alloy may have a thermal conductivity of about 125 W / m·K or less and a thermal conductivity of about 5.32×10 -6 Resistivity of Ω-cm or higher.

[0066] This written description uses examples to disclose the invention, including the best mode, and also to enable those skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

1. A fuse, include: a housing having opposing first and second ends; a fusible element positioned within the housing and including opposing first and second ends; as well as A first deep-drawn ferrule and a second deep-drawn ferrule, the first deep-drawn ferrule and the second deep-drawn ferrule are made of an aluminum alloy, wherein the first deep-drawn ferrule and the second deep-drawn ferrule are attached to a first end and a second end of the housing, respectively, and are electrically connected to a corresponding first end and a corresponding second end of the fusible element, the aluminum alloy is nickel-plated, wherein the nickel plating is chemical nickel plating, each of the first deep-drawn ferrule and the second deep-drawn ferrule comprises: a side wall surrounding the first end or the second end of the housing; as well as an end wall extending from the side wall and closing the first end or the second end of the shell, wherein the end wall includes a protrusion extending toward the inside of the shell and defining an inner surface of the end wall, and the thickness of the end wall is greater than the thickness of the side wall, wherein the side wall and the end wall define an internal receiver sized to receive a first end or a second end of the housing, wherein the first and second ends of the fusible element are connected to internal surfaces corresponding to protrusions of the respective first and second deep-drawn collars. 2 . The fuse according to claim 1 , wherein a thickness of the side wall is 0.50 mm or less. 3 . The fuse of claim 1 , wherein the aluminum alloy has a tensile strength of about 138 MPa or more.

4. The fuse of claim 1, wherein the yield strength of the aluminum alloy is about 117 MPa or higher.

5. The fuse of claim 1, wherein the melting point of the aluminum alloy is approximately 590°C or higher. 6 . The fuse of claim 1 , wherein a friction force between the side wall of the first deep-drawn ferrule or the second deep-drawn ferrule and the housing is about 150 Newtons or higher. 7 . The fuse of claim 6 , wherein an inner diameter of the inner receptacle is approximately 20 μm or less greater than an outer diameter of the housing.

8. The fuse according to claim 1, comprising two or more fusible links.

9. The fuse of claim 1, wherein the fusible element comprises a fusible wire.

10. The fuse of claim 1, wherein the fuse is configured as a time delay fuse, and the aluminum alloy has a thermal conductivity of about 125 W / m•K or less and a resistivity of about 5.32 x 10 -6 Ω-cm or higher.

11. A method for manufacturing a fuse, the method comprising: include: providing a housing including opposing first and second ends; Provide aluminum alloy sheets; constructing a ferrule from the aluminum alloy sheet by a deep drawing process, wherein the ferrule includes a side wall and an end wall extending from the side wall, the side wall and the end wall defining an internal receiver, the internal receiver being sized to receive the first end or the second end of the housing, the end wall including a protrusion extending from the end wall in the same direction as the side wall and defining an interior surface of the end wall, and the thickness of the end wall is greater than the thickness of the side wall; plating the ferrule with nickel; inserting a fusible wire into the interior of the housing, wherein the fusible wire includes a first end and a second end opposite to each other; Connecting the first end or the second end of the fusible wire to the protrusion of the ferrule; and The ferrule is secured to the housing by clamping the ferrule around the first end or the second end of the housing. The method according to claim 11 , wherein the nickel plating is chemical nickel plating.

13. The method of claim 11, wherein the aluminum alloy has a tensile strength of about 138 MPa or more.

14. The method of claim 11, wherein the aluminum alloy has a yield strength of about 117 MPa or more.

15. The method of claim 11, wherein the aluminum alloy has a melting point of about 590°C or higher.

16. The method of claim 11, wherein the friction between the side wall of the ferrule and the housing is about 150 Newtons or greater.

17. The method of claim 16, wherein an inner diameter of the inner receptacle is about 20 μm or less greater than an outer diameter of the housing.

18. The method of claim 11, wherein providing an aluminum alloy sheet further comprises subjecting the aluminum alloy sheet to a first heat treatment.

19. The method of claim 11, further comprising subjecting the ferrule to a second heat treatment.

20. The method of claim 11, wherein the fuse is configured as a time delay fuse, and the aluminum alloy has a thermal conductivity of about 125 W / m•K or less and a resistivity of about 5.32 x 10 -6 Ω-cm or higher.

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