CN115621099A - Chip type fuse and preparation method thereof - Google Patents

Abstract

The invention provides a chip fuse, which comprises a shell, electrode parts positioned at two ends of the shell and a fusing body part positioned in the shell, wherein the fusing body part comprises a first electrode part and a second electrode part; the electrode part and the fusing body part are integrally formed by bending the same metal strip; the electrode part comprises an electrode part and an electrode part, the electrode part covers the opening or the slot on the outer side of one end of the shell and enters the accommodating cavity to be connected with the electrode part, and the electrode part covers the outer end of the bottom wall and enters the accommodating cavity from the opening to be connected with the electrode part; at least one end of the accommodating cavity is sealed by the sealant, and the outer surface of the sealant is in contact with the outside air. The sealant is not in direct contact with the fusing body part, so that the aging risk of the sealant is greatly reduced. The invention also provides a preparation method of the chip type fuse.

Description

Chip type fuse and preparation method thereof

Technical Field

The invention relates to a chip fuse, in particular to a structure of a high-rated-current fuse with low temperature rise performance and a preparation method of the fuse.

Background

With the development of industries such as power batteries and small energy storage tools, the demand for large-current surface-mounted fuse products is more and more, and the temperature rise characteristic is particularly important. In consideration of the structural design of the product, the fuse product with the traditional tube-shell structure has the advantages that lead solder and the like are used for electrically connecting the internal metal melt with the external end cap through high-temperature melting welding and the like, and the limitation of the structure and the main performance indexes of the product obtained by the welding process, such as temperature rise and the like, is gradually highlighted along with the higher rated current of the product, so that a new product design is required for meeting the requirement.

Chinese patent 201380010087.4 proposes a structural design scheme in which a metal melt and a terminal are integrally formed, a metal sheet is stamped to form a specific pattern and structure, a process mode is adopted in which two sides of the metal sheet are used as end electrodes for welding and a fuse link playing a protective role in the middle is integrally formed on the same metal sheet, external electrodes on two sides are lapped on the bottom of a square insulating housing with an opening at one end, the fuse link is arranged in the insulating housing, and the opening end of the insulating housing is sealed by silicone resin or epoxy resin. The structure has the advantages that the contact resistance between the metal melt and the end electrode is mainly reduced, but the defect is obvious, the silicone resin and the like are positioned at the bottom end of the product, the heat dissipation is difficult, the silicone resin is directly contacted with the fuse link metal sheet, the heat accumulation is easy to cause, the sealing resin can age along with the increase of the service time and the temperature of the product, and the end electrode, the fuse link and the like fall off.

Therefore, a new technical solution is needed to solve the above technical problems.

Disclosure of Invention

In view of the above problems, the present invention provides a chip fuse to solve the problem that when an electrode portion and a fuse body portion are integrally formed by a metal sheet, a sealant at an end portion of a housing is aged to cause the electrode portion to easily fall off.

The invention also provides a preparation method of the chip fuse.

In order to realize the target functions, the chip type fuse adopts the following technical scheme:

a chip fuse comprises a shell, electrode parts positioned at two ends of the shell, and a fusing body part positioned in the shell; the electrode part and the fusing body part are integrally formed by bending the same metal strip; the shell comprises a top wall, a bottom wall and two side walls, wherein the top wall, the bottom wall and the two side walls enclose an accommodating cavity, and two ends of the shell are provided with openings and/or slots; the electrode parts at two ends comprise an electrode long part and an electrode short part, the electrode long part covers the opening or the slot at the outer side of one end of the shell and enters the accommodating cavity to be connected with the electrode part, and the electrode short part covers the outer end of the bottom wall and enters the accommodating cavity from the opening to be connected with the electrode part; at least one end of the accommodating cavity is sealed by the sealant, and the outer surface of the sealant is in contact with the outside air.

Furthermore, one end of the shell is provided with an end wall, the other end of the shell is provided with an opening, the end wall is provided with a slot communicated with the accommodating cavity, and the long electrode part covers the end wall and the outer side of the slot and extends into the accommodating cavity from the slot to be connected with the electrode part; the electrode part extends obliquely downwards in the accommodating cavity from the position where the electrode part is connected with the long electrode part and is connected with the short electrode part; and sealing glue is arranged at the opening and the groove to seal the opening and the groove.

Further, the opening area is the same as the cross-sectional area of the containing cavity; the short electrode part covers the outer end of the bottom wall and is bent and extended to the bottom of the bottom wall; the cross sectional area of the slot is smaller than that of the containing cavity, and the long electrode part covers the end wall, bends and extends to the bottom of the bottom wall from the outer side of the end wall.

Further, the containing cavity is filled with arc extinguishing materials wrapping the fusing body part.

Furthermore, openings are formed in two ends of the shell, a concave part which is inclined inwards to form a chamfer is formed in one end of the bottom wall, an elastic protruding part which is bent inwards is arranged on the long electrode part, and the protruding part abuts against the concave part; the long electrode part covers and seals the opening completely and is attached to the inner surface of the top wall to extend into the containing cavity and be connected with the fusing body part.

Furthermore, the opening area of one end of the concave part arranged on the bottom wall of the shell is larger than the cross section area of the accommodating cavity; the opening area of the other end of the shell is the same as the cross section area of the containing cavity.

Furthermore, the opening at the end where the long electrode part is located is not provided with the sealant, and the end where the short electrode part is located is covered with the sealant for sealing.

Has the advantages that:

due to the adoption of the technical scheme, the invention has the following advantages: in the structure of the chip fuse, the metal strip is firmly fixed at the two ends of the shell through diagonal bending, so that the potential risk of falling off of the insulating shell of similar products in the industry is avoided; in addition, in the structure of the chip fuse, at least one surface of the sealant is in contact with the air and is not in direct contact with the fuse body part, so that the aging risk of the sealant is greatly reduced, and the service life of a product is prolonged.

The invention also provides a preparation method of the chip type fuse, which comprises the following steps:

step (1): punching a metal strip to form a fuse body;

step (2): penetrating a metal strip which is punched to form the fusing body into the accommodating cavity from the open slot of the insulating shell, and penetrating out from the opening side of the other end of the insulating shell;

and (3): bending the metal strip penetrating into the accommodating cavity downwards along the end face of the lower side wall to form a short electrode part, and then bending the metal strip inwards along the bottom surface of the bottom wall to form a welding surface, so that the metal strip is completely fixed on the shell;

and (4): placing the end of the shell with the welding surface downwards, dispensing and sealing the end of the shell in the slot of the shell by using a dispenser, and curing the sealing glue;

and (5): the opening surface of the shell is upward, the sealed surface is downward, and arc extinguishing materials are filled into the accommodating cavity and are compacted;

and (6): and sealing the opening on the surface of the arc-extinguishing material by filling sealant, and curing.

The invention also provides another preparation method of the chip type fuse, which comprises the following steps:

step (1): punching a metal strip to form a fuse body; stamping and bending the design required position to form a convex part;

step (2): penetrating a metal strip which is punched to form the fusing body part into the accommodating cavity from the open slot of the insulating shell and penetrating out from the opening side at the other end;

and (3): firstly, tensioning a metal strip, enabling a convex part on the metal strip to be tightly attached to the concave part of the shell, enabling the upper end of the metal strip to be tightly attached to the inner surface of the top wall through the elastic force of the convex part, then bending two end parts of the metal strip towards the bottom of the bottom wall simultaneously to form a welding surface, and simultaneously sealing one end of the shell by the width of the metal strip;

and (4): the opening surface of the shell is upward, the sealed surface is downward, and arc extinguishing materials are filled into the accommodating cavity and are compacted;

and (5): and sealing the opening on the surface of the arc-extinguishing material by filling the sealant, and curing.

Drawings

FIG. 1 is a longitudinal cross-sectional view of a chip-type fuse in accordance with one embodiment of the present invention;

FIG. 2 is a perspective view of an insulating housing for a fuse according to an embodiment of the present invention;

FIG. 3 is a flow chart of a method for manufacturing a fuse according to an embodiment of the present invention;

FIG. 4 is a longitudinal cross-sectional view of a chip-type fuse in accordance with a second embodiment of the present invention;

FIG. 5 is a schematic view of the second embodiment of the present invention after assembling the metal strip bent to form the electrode portion and the fuse portion with the housing;

FIG. 6 is a longitudinal sectional view of an insulating housing for a fuse in accordance with a second embodiment of the present invention;

FIG. 7 is a cross-sectional view of a melt penetration structure in a fuse according to a second embodiment of the present invention;

FIG. 8 is a schematic view of stamping a strip in a fuse manufacturing process according to a second embodiment of the present invention.

Detailed Description

The following examples illustrate the invention in detail:

the invention is described in detail below with reference to the figures and examples.

The first embodiment is as follows:

as shown in fig. 1 to 3, the present embodiment provides a chip fuse including: an insulating shell 1, a metal strip 2, an arc-extinguishing material 3 and a sealant 4. Wherein:

the insulating shell 1 comprises a top wall, a bottom wall and two side walls, and the top wall, the bottom wall and the two side walls enclose to form an accommodating cavity. One end of the accommodating cavity is a full opening, the other end of the accommodating cavity is an end wall, a set of transversely extending slots 11 are formed in the end wall, and the slots 11 are communicated with the accommodating cavity. The insulating shell 1 is of a tubular structure, is formed by high-temperature sintering of ceramic materials such as alumina and the like through molding processes such as hot-press casting and the like, and has high heat conductivity, mechanical strength and heat resistance; and can also be injection molded by high-temperature resistant resin such as epoxy resin, polyphenylene sulfide and the like. The inside of the insulating housing 1 may have a circular cross section, a square cross section, or other irregular pattern cross section.

The metal strip 2 is formed by integrally molding an end electrode portion 21 and a fuse body portion 22, is made of a metal material such as copper, silver, or an alloy thereof, and is subjected to a treatment such as silver plating, nickel plating, or tin plating on the surface thereof. The metal strip 2 adopts a diagonal structure design, two end electrode parts 21 are respectively fixed on two surfaces of an opening of the insulating shell 1, namely, a fusing body part 22 of the metal strip 2 is obliquely arranged in the tubular insulating shell 1, the end electrode parts 21 are bent downwards along two opposite openings or slotted end surfaces of the insulating shell 1 to form fusing body side electrodes 211, and are bent inwards along the outer surface of the side wall of the insulating shell 1 to form welding surface electrodes 212 of the fusing body.

The arc extinguishing material 3 is solid particles of 50-150 meshes of quartz sand or gas-generating arc extinguishing materials and the like; the arc extinguishing material 3 is filled in the inner cavity of the insulating shell 1 and is compacted, so that the arc extinguishing material is tightly wrapped around the fusing body 22 in the metal strip 2, and the effects of reducing temperature rise in the normal use process of a product and quickly extinguishing electric arcs when the product is abnormally fused are achieved.

The sealant 4 is high-temperature-resistant silica gel or silicone gel and is used for sealing the opening part of the insulating shell 1, is in close contact with the surface of the arc extinguishing material 3 and is separated from the fusing body part 22, so that the fusing body part 22 is prevented from directly and continuously heating the arc extinguishing material, the heat dissipation condition of the arc extinguishing material is greatly improved, the phenomenon that the sealant 4 falls off due to the aging condition of the sealant 4 caused by the accumulated heat inside the product when the product works at abnormal current for a long time is avoided, and the service life of the product is greatly prolonged.

Referring to fig. 3, a method for manufacturing a chip-type fuse according to a first embodiment of the present invention includes the following steps:

step (1): punching the metal strip 2 as required to form the fuse body portion 22;

step (2): the metal strip 2 which is punched to form the fusing body part 22 penetrates into the insulating shell 1 from the semi-closed opening 11 side of the insulating shell 1 and penetrates out from the full opening side;

and (3): bending the metal strip 2 penetrating into the insulating shell 1 downwards along the end face of the insulating shell 1 to form a side electrode 211 of the fuse, and then bending the metal strip inwards along the side wall of the bottom of the insulating shell 1 to form a welding surface electrode 212 of the fuse, so that the metal strip 2 is completely fixed on the insulating shell 1;

and (4): placing the side wall of the insulating shell 1 with the welding surface electrode 212 downwards, dispensing and sealing the incompletely closed position in the semi-closed surface of the insulating shell 1 by using a dispenser, and curing the sealing glue by adopting a proper process;

and (5): the opening surface of the insulating shell 1 is upward, the sealed surface is downward, quartz sand is filled into the insulating shell 1 as an arc extinguishing material 3 through a sand vibrating process and the like, and the insulating shell is compacted. The quartz sand is 50-150 meshes, the filling height is at least lower limit of the filling height of the quartz sand which does not exceed the fusing body part 22 in the metal strip 2, and the upper limit of the filling height is to ensure that the sealant 4 has enough bonding contact area so as to provide required bonding strength;

and (6): and filling the sealant 4 on the surface of the quartz sand arc-extinguishing material 3 through a dispenser, and curing to obtain the chip-type fuse disclosed by the first embodiment of the invention.

Example two:

fig. 4 to 8 show another structure of the chip fuse of the present invention, which is different from the first embodiment mainly in that: the two ends of the insulating shell 1 of the chip type fuse are both in a full-open state, and the structure of the insulating shell is similar to that of a ceramic tube used in a traditional fuse, as shown in fig. 6. An open end face of the insulating housing 1, the rear face of which is designed as the inner face which is in contact with the fuse-bonding face electrode, is provided with a concave portion 12 with a larger chamfer, and accordingly the metal strip 2 is stamped and bent at the lower part of the side face electrode position to form an elastic convex portion 23, and the convex portion 23 abuts against the concave portion 12. The long electrode portion 211 completely covers and closes the opening and is closely attached to the inner surface of the ceiling wall. The electrode portion 211 is fixed to the top wall and the concave portion 12 by the elastic force of the elastic protrusion 23 from the inner surface of the top wall, and the position of the metal strip 2 when the melt penetrates is restricted, so that the metal strip 2 can be tensioned more easily, as shown in fig. 7. As shown in fig. 6, the concave part 12 is provided, so that the opening area of the end of the insulating housing 1, which is provided with the concave part on the bottom wall, is larger than the cross-sectional area of the accommodating cavity; the opening area of the other end of the insulating housing 1 is the same as the cross-sectional area of the accommodating cavity. Since the long electrode portion 211 serves as both an electrode and a sealing portion for covering and sealing an opening at one end of the insulating housing 1, the opening at the end where the long electrode portion 211 is located is not provided with a sealant, and the end where the short electrode portion 213 is located is covered with a sealant for sealing 4.

The preparation method of the chip fuse in the second embodiment of the invention comprises the following steps:

step (1): punching the metal strip 2 as required to form a fusing body part 22, punching and bending the metal strip at a position required by design to form a protruding part 23, wherein the downward bending distance of the protruding part 23 is equivalent to the height of an inner cavity of the insulating shell 1;

step (2): passing the metal strip 2 punched to form the fuse body portion 22 through the inside of the insulating case 1;

and (3): firstly, tensioning a metal strip 2 penetrating into an insulating shell 1 to enable a convex part 23 on the metal strip 2 to be tightly attached to a concave part 12 of the insulating shell 1, then bending two end parts of the metal strip 2 towards the inner side of the insulating shell 1 simultaneously to form a welding surface electrode 212, and meanwhile, sealing one end of the insulating shell 1 by the width of the metal strip 2;

and (4): the opening surface of the insulating shell 1 is upward, the closed surface is downward, quartz sand is filled into the insulating shell 1 as an arc extinguishing material 3 through a sand vibrating process and the like, and the insulating shell is compacted. The quartz sand is 50-150 meshes, the filling height is at least lower limit of the filling height of the quartz sand which does not exceed the fusing body part 22 in the metal strip 2, and the upper limit of the filling height is to ensure that the sealant 4 has enough bonding contact area so as to provide required bonding strength;

and (5): and filling the sealant 4 on the surface of the quartz sand arc-extinguishing material 3 through a dispenser, and curing to obtain the chip-type fuse disclosed by the second embodiment of the invention.

The technical means disclosed in the scheme of the invention are not limited to the technical means disclosed in the above embodiments, but also include the technical means formed by any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and such improvements and modifications are also considered to be within the scope of the present invention.

Claims (10)

1. A chip fuse comprises a shell, electrode parts positioned at two ends of the shell, and a fusing body part positioned in the shell; the electrode part and the fusing body part are integrally formed by bending the same metal strip; the portable multifunctional portable electronic device is characterized in that the shell comprises a top wall, a bottom wall and two side walls, wherein the top wall, the bottom wall and the two side walls form an accommodating cavity in an enclosing mode, and openings and/or slots are formed in two ends of the shell;

the electrode parts at two ends comprise an electrode long part and an electrode short part, the electrode long part covers the opening or the slot at the outer side of one end of the shell and enters the accommodating cavity to be connected with the electrode part, and the electrode short part covers the outer end of the bottom wall and enters the accommodating cavity from the opening to be connected with the electrode part; at least one end of the accommodating cavity is sealed by the sealant, and the outer surface of the sealant is in contact with the outside air.

2. A chip fuse as recited in claim 1, wherein: one end of the shell is provided with an end wall, the other end of the shell is provided with an opening, the end wall is provided with a slot communicated with the accommodating cavity, and the long electrode part covers the end wall and the outer side of the slot and extends into the accommodating cavity from the slot to be connected with the electrode part; the electrode part extends downwards in the containing cavity in an inclined way from the position where the electrode part is connected with the long electrode part and is connected with the short electrode part; and sealing glue is arranged at the opening and the groove to seal the opening and the groove.

3. A chip fuse as claimed in claim 2, wherein: the opening area is the same as the cross sectional area of the accommodating cavity; the short electrode part covers the outer end of the bottom wall and is bent and extended to the bottom of the bottom wall; the cross sectional area of the slot is smaller than that of the containing cavity, and the long electrode part covers the end wall, bends and extends to the bottom of the bottom wall from the outer side of the end wall.

4. A chip fuse as recited in claim 2 or 3, wherein: the containing cavity is filled with arc extinguishing materials wrapping the fusing body part.

5. A chip fuse as claimed in claim 1, wherein: the two ends of the shell are provided with openings, one end of the bottom wall is provided with a concave surface part which is inclined inwards to form a chamfer, the long electrode part is provided with an elastic convex part which is bent inwards, and the convex part is abutted against the concave surface part; the long electrode part covers and seals the opening completely and is tightly attached to the inner surface of the top wall, and the long electrode part extends from the inner surface of the top wall into the containing cavity and is connected with the fusing body part.

6. A chip fuse as claimed in claim 5, wherein: the opening area of one end of the bottom wall of the shell, which is provided with the concave surface part, is larger than the cross section area of the accommodating cavity; the opening area of the other end of the shell is the same as the cross sectional area of the containing cavity.

7. A chip fuse as claimed in claim 5 or 6, wherein: the opening at the end where the long electrode part is located is not provided with the sealant, and the end where the short electrode part is located is covered with the sealant for sealing.

8. A chip fuse in accordance with claim 7, wherein: arc extinguishing materials wrapping the fusing body part are filled in the accommodating cavity.

9. A method for manufacturing a chip fuse according to any one of claims 2 to 4, comprising the steps of:

step (1): stamping a metal strip to form a fuse body;

step (2): penetrating a metal strip which is punched to form the fusing body into the accommodating cavity from the open slot of the insulating shell, and penetrating out from the opening side of the other end of the insulating shell;

and (3): bending the metal strip penetrating into the accommodating cavity downwards along the end face of the lower side wall to form a short electrode part, and then bending the metal strip inwards along the bottom face of the bottom wall to form a welding face, so that the metal strip is completely fixed on the shell;

and (4): placing the end of the shell with the welding surface downwards, dispensing and sealing the end of the shell in the slot of the shell by using a dispenser, and curing the sealing glue;

and (5): the opening surface of the shell is upward, the sealed surface is downward, and arc extinguishing materials are filled into the accommodating cavity and compacted;

and (6): and sealing the opening on the surface of the arc-extinguishing material by filling the sealant, and curing.

10. A method for manufacturing a chip fuse according to any one of claims 5 to 8, comprising the steps of:

step (1): punching a metal strip to form a fuse body; stamping and bending the design required position to form a convex part;

step (2): penetrating a metal strip which is punched to form the fusing body part into the accommodating cavity from the open slot of the insulating shell and penetrating out from the opening side at the other end;

and (3): firstly, tensioning a metal strip, enabling a convex part on the metal strip to be tightly attached to a concave surface part of the shell, enabling the upper end of the metal strip to be tightly attached to the inner surface of the top wall through the elastic force of the convex part, bending two end parts of the metal strip towards the bottom of the bottom wall simultaneously to form a welding surface, and sealing one end of the shell by the width of the metal strip;

and (4): the opening surface of the shell is upward, the sealed surface is downward, and arc extinguishing materials are filled into the accommodating cavity and are compacted;

and (5): and sealing the opening on the surface of the arc-extinguishing material by filling the sealant, and curing.

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