Melt for fuse and fuse

Abstract

The invention relates to a fuse body for a fuse and the fuse. The melt has a longitudinal direction in a length direction and a transverse direction in a width direction, and includes: a main body; a first fusing part including a first group of through holes arranged in the main body in a lateral direction and a first group of narrow paths formed in the main body in an orientation of the first group of through holes, in which an area of a cross section of each of the first group of narrow paths is constant in a longitudinal direction; the second fusing part and the first fusing part are arranged in a spaced mode in the longitudinal direction, the second fusing part comprises a second set of through holes formed in the main body in the transverse direction and a second set of narrow diameters formed in the main body in the orientation of the second set of through holes, and in the longitudinal direction, the area of the cross section of each narrow diameter in the second set of narrow diameters is gradually reduced in the direction close to the center of the narrow diameter; wherein the transverse spacing between two adjacent narrow paths in the first group of narrow paths is smaller than the transverse spacing between two adjacent narrow paths in the second group of narrow paths.

Description

Technical Field

[0001] The invention relates to the technical field of circuit short circuit and overload protection, in particular to a fuse element and a fuse for a fuse. Background Art

[0002] A fuse is a circuit protection device that uses the heat generated by itself to melt the fuse within a certain time range when the current exceeds the specified value, thereby disconnecting the circuit. At present, fuses are widely used in the field of electric vehicles. In the early days of electric vehicle development, the requirements for the distribution system were: large breaking capacity, miniaturization, and fast fusing. For this reason, AR fast fuses are generally used to protect the distribution system. With the gradual standardization of the electric vehicle industry, more and higher requirements are put forward for fuses used to protect the distribution system to meet the protection needs of different loads under various working conditions. For example, there is a demand that in addition to the characteristics of the original AR type fuse, the fuse should also have 1.1In (1.1 times the rated current) overload tolerance, 2In, 3In and 5In overload and short-circuit protection capabilities. Summary of the invention

[0003] The present invention aims to provide a fuse element for a fuse which can at least solve part of the above-mentioned technical problems.

[0004] The present invention also aims to provide a fuse using the improved fuse.

[0005] According to one aspect of the present invention, there is provided a fuse element for a fuse, having a longitudinal direction along the length direction and a transverse direction along the width direction, the fuse element comprising: a main body; a first fuse portion, comprising a first group of through holes arranged in the main body along the transverse direction and a first group of narrow diameters formed in the main body along the orientation of the first group of through holes, wherein in the longitudinal direction, the cross-sectional area of ​​each narrow diameter in the first group of narrow diameters is constant; a second fuse portion, arranged at intervals from the first fuse portion along the longitudinal direction, the second fuse portion comprising a second group of through holes arranged in the main body along the transverse direction and a second group of narrow diameters formed in the main body along the orientation of the second group of through holes, wherein in the longitudinal direction, the cross-sectional area of ​​each narrow diameter in the second group of narrow diameters gradually decreases in a direction close to the center of the narrow diameter; wherein the transverse spacing between two adjacent narrow diameters in the first group of narrow diameters is smaller than the transverse spacing between two adjacent narrow diameters in the second group of narrow diameters.

[0006] According to the fuse provided by this scheme, the first group of narrow diameters of the first fuse part and the second group of narrow diameters of the second fuse part form a differentiated design in the shape of a single narrow diameter and the lateral spacing between the narrow diameters, wherein in the first group of narrow diameters, each narrow diameter is constructed into a rectangle with a substantially constant cross section, and the lateral spacing between adjacent narrow diameters is small, while in the second group of narrow diameters, each narrow diameter is constructed into a waist shape with a smaller cross section as it approaches the middle, and the lateral spacing between adjacent narrow diameters is large. Through this differentiated design, the first group of narrow diameters is easier to collect heat than the second group of narrow diameters, so that the two groups of narrow diameters form differences in thermal conductivity and heat dissipation coefficient, meeting the requirements of 1.1In overload tolerance and 2In, 3In and 5In overload and short-circuit protection. Through the differentiated narrow diameter design, the fuse can be made of low-cost conductor materials (such as copper). At this time, the product still has a high breaking capacity and a wide range of overcurrent protection capabilities, while also meeting harsh environmental loads and current shock application conditions.

[0007] In some embodiments, the cross-sectional areas of each of the first set of narrow paths are consistent.

[0008] In some embodiments, the areas of the smallest cross-sections of the respective narrow paths in the second group of narrow paths are consistent.

[0009] In some embodiments, the cross-sectional area of ​​any narrow path in the first group of narrow paths is equal to the smallest cross-sectional area of ​​any narrow path in the second group of narrow paths.

[0010] In some embodiments, the first group of through holes includes a plurality of first through holes arranged in the body along the transverse direction, wherein the first group of narrow paths includes a narrow path formed between two adjacent first through holes.

[0011] In some embodiments, the first group of through holes also includes a plurality of second through holes arranged along the transverse direction on opposite sides of the plurality of first through holes, wherein the lateral dimensions of the plurality of second through holes are greater than the lateral dimensions of the plurality of first through holes, and wherein the first group of narrow diameters also includes a narrow diameter formed between adjacent first through holes and second through holes.

[0012] In some embodiments, at least a portion of a side of the first through hole adjacent to another first through hole or adjacent to the second through hole is configured as a straight edge, and at least a portion of a side of the second through hole adjacent to the first through hole is configured as a straight edge.

[0013] In some embodiments, the second group of through holes includes a plurality of third through holes arranged along the transverse direction on the main body, the transverse dimension of the third through holes is larger than the transverse dimension of the first through holes, and the second group of narrow diameters includes a narrow diameter formed between two adjacent third through holes.

[0014] In some embodiments, a side edge of the third through hole adjacent to another third through hole is configured as an arc edge protruding toward the another third through hole.

[0015] According to another aspect of the present invention, a fuse is provided, comprising: a shell; two terminals, respectively arranged at opposite ends of the shell; a fuse connected between the two terminals in the shell, wherein the fuse is the aforementioned fuse; and an arc extinguishing medium filled in the shell.

[0016] Some of the other features and advantages of the present invention will be apparent to those skilled in the art after reading this application, and the other parts will be described in the following specific embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The embodiments of the present invention are described in detail below with reference to the accompanying drawings, wherein:

[0018] Figure 1 is a cross-sectional view of a fuse according to an embodiment of the present invention;

[0019] Figure 2 is a schematic diagram of a melt according to an embodiment of the present invention.

[0020] Description of reference numerals:

[0021] 1. Fuse; 2. Shell; 3. Lining; 4. Terminal; 5. Melt; 6. Main body; 7.

[0022] first fuse portion; 71, first through hole; 72, second through hole; 73, first narrow diameter;

[0023] 8, second fuse; 81, third through hole; 83, second narrow diameter; L, longitudinal direction; W,

[0024] Horizontal DETAILED DESCRIPTION

[0025] Now, with reference to the accompanying drawings, the fuse element for fuse and the schematic scheme of the fuse disclosed in the present invention are described in detail. Although the accompanying drawings are provided to present some embodiments of the present invention, the accompanying drawings do not have to be drawn according to the dimensions of the specific embodiments, and certain features may be enlarged, removed or partially cut to better illustrate and explain the disclosure of the present invention. Some components in the accompanying drawings can be adjusted in position according to actual needs without affecting the technical effect. The phrase "in the accompanying drawings" or similar terms appearing in the specification do not necessarily refer to all drawings or examples.

[0026] Certain directional terms used to describe the drawings below, such as "inside", "outside", "above", "below" and other directional terms, will be understood to have their normal meanings and refer to those directions involved when the drawings are normally viewed. Unless otherwise specified, the directional terms described in this specification are basically in accordance with the conventional directions understood by those skilled in the art.

[0027] The terms "first", "first", "second", "second" and the like used in the present invention do not indicate any order, quantity or importance, but are used to distinguish one component from other components.

[0028] Figure 1 The fuse according to an embodiment of the present invention is shown. As shown in the figure, the fuse 1 includes a shell 2, a terminal 4 and a fuse 5. The shell 2 can be cylindrical or any other suitable shape, and defines a cavity that passes through in the longitudinal direction L. In one embodiment, the shell 2 is an integral part made by an integrated molding process. In another embodiment, the shell 2 is composed of two half shells spliced ​​together, wherein the two half shells can be combined together by welding or the like. The two terminals 4 are respectively located at opposite ends of the cavity. A lining 3, for example, for sealing, can be sandwiched between the outer periphery of the terminal 4 and the inner periphery of the shell 2. The lining 3 can extend along the entire longitudinal length L of the shell 2. The fuse 5 is connected between the two terminals 4 in the cavity of the shell 2, and the cavity of the shell 2 is filled with an arc-extinguishing medium that wraps the fuse 5, such as quartz sand. The fuse 5 and the two terminals 4 can each be made by an integrated molding process and connected together by welding or other suitable electrical connection methods. Alternatively, the fuse 5 and the two terminals can also be an integral part formed in one piece. The fuse 5 can be made of a suitable conductor material, such as copper, zinc, silver, etc., preferably copper. The melt 5 is described in detail below by taking the melt 5 made of copper as an example.

[0029] Figure 2 A plan view of a melt according to an embodiment of the present invention is shown. As shown in the figure, the melt 5 is in a sheet shape, has a longitudinal direction L along the length direction and a transverse direction W along the width direction, and has a thickness direction perpendicular to the length direction and the width direction (not shown in the figure). The body 6 of the melt 5 is made of copper material, and a first fuse part 7 and a second fuse part 8 of a differentiated design are formed thereon.

[0030] The first fuse portion 7 is, for example, located approximately in the middle of the main body 6 along the longitudinal direction L, and a first group of through holes arranged along the transverse direction W are formed on the main body 6. Figure 2As shown, the first group of through holes includes two first through holes 71 arranged along the transverse direction W on the main body 6 and two second through holes 72 located on opposite sides of the two first through holes 71 along the transverse direction W. Both the first through hole 71 and the second through hole 72 penetrate the entire main body 6 along the thickness direction. The dimension of the first through hole 71 along the transverse direction W is smaller than the dimension of the second through hole 72 along the transverse direction W. In the embodiment shown, the two second through holes 72 each extend to the corresponding side edge of the main body 6. Narrow diameters 73 are formed between two adjacent first through holes 71 and between adjacent first through holes 71 and second through holes 72. These narrow diameters 73 are arranged along the orientation of the first group of through holes and constitute the first group of narrow diameters. For the sake of distinction, these narrow diameters 73 constituting the first group of narrow diameters are also referred to as first narrow diameters 73 herein.

[0031] The first narrow path 73 is substantially rectangular as a whole, and the area S1 of its cross section is substantially constant in the longitudinal direction L. In the illustrated embodiment, the first through hole 71 and the second through hole 72 are respectively rounded rectangles, but it can be understood that the effect of the rounded corners on the area of ​​the cross section of the first narrow path 73 can be ignored for the intended purpose of the present invention. In an embodiment not shown, the first through hole and the second through hole can be rectangular with right angles. In another embodiment not shown, the side of the first through hole adjacent to another first through hole and the side adjacent to the second through hole are straight sides, and the side of the second through hole adjacent to the first through hole is a straight side, thereby forming a rectangular first narrow path with a substantially constant cross section between two adjacent first through holes and between the adjacent first through hole and the second through hole, in which case the other two sides of the first through hole and the other two sides of the second through hole may not be straight sides, but other shapes, such as arc sides.

[0032] In the first group of narrow paths, the cross-sectional area S1 of all first narrow paths 73 is consistent. In this way, the first narrow paths 73 included in the first group of narrow paths can ensure the consistency of arc starting time and arc burning time under the condition of large current (for example, 5In-20KA breaking current). In this article, "arcing time" refers to the time from the current exceeding the rated value to the arc generated inside the fuse when the fuse is overloaded or short-circuited in the circuit. The shorter this time, the faster the fuse can cut off the power supply, thereby protecting electrical equipment and personal safety. "Arc burning time" refers to the duration from the start of arc generation to the arc extinguishing.

[0033] The second fuse part 8 is arranged on the main body 6 in a spaced relationship from the first fuse part 7 along the longitudinal direction L, and a second group of through holes arranged along the transverse direction W is formed on the main body 6. As shown in the figure, the second group of through holes includes four third through holes 81 arranged along the transverse direction W on the main body 6. These third through holes 81 all penetrate the entire main body 6 along the thickness direction. The dimension of the third through hole 81 along the transverse direction W is greater than the dimension of the first through hole 71 along the transverse direction W. In the illustrated embodiment, the two third through holes 81 located at the outermost sides in the transverse direction each extend to the corresponding side edge of the main body 6. A narrow diameter 83 is formed between two adjacent third through holes 81, and these narrow diameters 83 are arranged along the orientation of the second group of through holes and constitute a second group of narrow diameters. For the sake of distinction, these narrow diameters 83 constituting the second group of narrow diameters are also referred to as second narrow diameters 83 in this article.

[0034] The second narrow diameter 83 is generally waist-shaped and narrows in the middle, and the area of ​​its cross section is gradually reduced from both ends to the center in the longitudinal direction L, and forms a minimum cross section of area S2 at the longitudinal center of the second narrow diameter 83. In the illustrated embodiment, the side of the third through hole 81 adjacent to another third through hole 81 is an arc-shaped side protruding toward the adjacent other third through hole 81, thereby forming a waist-shaped second narrow diameter 83 between two adjacent third through holes 81, and the other two sides of the third through hole 81 are straight sides. In an embodiment not shown, in addition to the side of the third through hole adjacent to another third through hole being an arc-shaped side protruding toward the adjacent other third through hole, the other two sides of the third through hole can also be arc-shaped sides, thereby, for example, the third through hole can be configured into a circular, elliptical, or other shape.

[0035] In the second group of narrow paths, the minimum cross-sectional area S2 of all second narrow paths 83 is consistent. Thus, the second narrow paths 83 included in the second group of narrow paths can ensure the consistency of arc starting time and arc burning time under the condition of large current (for example, breaking current of 5In-20KA).

[0036] Since the dimension of the first through hole 71 along the lateral direction W is smaller than the dimension of the third through hole 81 along the lateral direction W, the lateral spacing between two adjacent first narrow diameters 73 in the first group of narrow diameters is smaller than the lateral spacing between two adjacent second narrow diameters 83 in the second group of narrow diameters. In this way, the first group of narrow diameters forms a differentiated design with the second group of narrow diameters in terms of the shape of a single narrow diameter and the lateral spacing between the narrow diameters. This differentiated design makes it easier for the first group of narrow diameters to collect heat than the second group of narrow diameters, resulting in a difference in thermal conductivity and heat dissipation coefficient between the first group of narrow diameters and the second group of narrow diameters. This differentiated design is also conducive to meeting the fusing characteristics below 2In. Under the same overcurrent conditions, the first group of narrow diameters will fuse earlier than the second group of narrow diameters. Based on different overcurrents, the time difference between the first group of narrow diameters and the second group of narrow diameters will also be different. For example, under 20KA conditions, the time difference is less than 100ms.

[0037] Under the condition that the cross-sectional area S1 of all the first narrow paths 73 included in the first narrow path group is consistent, and the minimum cross-sectional area S2 of all the second narrow paths 83 included in the second narrow path group is consistent, the size relationship between S1 and S2 can be designed according to the required product characteristics. In one embodiment, S1=S2.

[0038] like Figure 1 and Figure 2 As shown, two second fuse parts 8 are arranged on opposite sides of the first fuse part 7 along the longitudinal direction L. However, it can be understood that the number of the first fuse part 7 and the second fuse part 8 can be designed according to the required product features. For example, only one first fuse part 7 and one second fuse part 8 can be arranged on the main body 6.

[0039] In addition, although the figure shows that the first fuse part 7 includes two first through holes 71 and two second through holes 72, and the second fuse part 8 includes four third through holes 81, it can be understood that the number and size of the first through holes 71, the second through holes 72 and the third through holes 81 can be adjusted, as long as the cross-section of the first narrow diameter in the constructed first group of narrow diameters can be basically balanced, and the cross-section of the second narrow diameter in the second group of narrow diameters gradually decreases in the direction approaching the center, and the lateral spacing between two adjacent first narrow diameters is smaller than the lateral spacing between two adjacent second narrow diameters, so as to meet the differentiated design requirements of the first group of narrow diameters and the second group of narrow diameters.

[0040] For example, in an embodiment not shown, the first group of through holes of the first fuse portion is composed of a plurality of first through holes of the same transverse size (i.e., the second through hole is omitted), and a rectangular first narrow diameter with a substantially constant cross section is formed between two adjacent first through holes, while the second fuse portion is composed of a plurality of third through holes of the same transverse size, and a waist-shaped second narrow diameter with a cross section gradually narrowing toward the center is formed between two adjacent third through holes. The transverse size of the third through hole is larger than that of the first through hole, so that the transverse spacing between two adjacent first narrow diameters in the first group of narrow diameters is smaller than the transverse spacing between two adjacent second narrow diameters in the second group of narrow diameters. In this way, the first group of narrow diameters forms a differentiated design with the second group of narrow diameters in terms of the shape of a single narrow diameter and the transverse spacing between the narrow diameters as in the sense of the present application.

[0041] It should be understood that although this specification is described according to various embodiments, not every embodiment contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0042] The above description is only an illustrative embodiment of the present invention and is not intended to limit the scope of the present invention. Any equivalent changes, modifications and combinations made by any person skilled in the art without departing from the concept and principle of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A fuse element for a fuse having a longitudinal direction (L) and a transverse direction (W) along a length direction, characterized in that: The melt comprises: Subject (6); a first fuse portion (7), comprising a first group of through holes arranged in the body (6) along the transverse direction (W) and a first group of narrow diameters formed in the body (6) along the orientation of the first group of through holes, wherein in the longitudinal direction (L), the cross-sectional area of ​​each narrow diameter in the first group of narrow diameters is constant; a second fuse portion (8) arranged in a spaced relationship from the first fuse portion (7) along the longitudinal direction (L), the second fuse portion (8) comprising a second group of through holes arranged in the body (6) along the transverse direction (W) and a second group of narrow paths formed in the body (6) along the orientation of the second group of through holes, wherein in the longitudinal direction (L), the cross-sectional area of ​​each narrow path in the second group of narrow paths gradually decreases in a direction approaching the center of the narrow path; The transverse distance between two adjacent narrow paths in the first group of narrow paths is smaller than the transverse distance between two adjacent narrow paths in the second group of narrow paths.

2. The fuse element for fuse according to claim 1, characterized in that: The cross-sectional areas of the narrow paths in the first group of narrow paths are consistent.

3. The fuse element for fuse according to claim 1, characterized in that: The areas of the minimum cross sections of the narrow paths in the second group of narrow paths are consistent.

4. The fuse element for fuse according to claim 1, characterized in that: The cross-sectional area of ​​any narrow path in the first group of narrow paths is equal to the minimum cross-sectional area of ​​any narrow path in the second group of narrow paths.

5. The fuse element for a fuse according to any one of claims 1 to 4, characterized in that: The first group of through holes comprises a plurality of first through holes (71) arranged in the body (6) along the transverse direction (W), wherein the first group of narrow diameters comprises a narrow diameter formed between two adjacent first through holes (71).

6. The fuse element for fuse according to claim 5, characterized in that: The first group of through holes also includes a plurality of second through holes (72) arranged along the transverse direction (W) on opposite sides of the plurality of first through holes (71), wherein the transverse dimensions of the plurality of second through holes (72) are greater than the transverse dimensions of the plurality of first through holes (71), and wherein the first group of narrow diameters also includes a narrow diameter formed between adjacent first through holes (71) and second through holes (72).

7. The fuse element for fuse according to claim 6, characterized in that: At least a portion of the side of the first through hole (71) adjacent to another first through hole (71) or adjacent to the second through hole (72) is configured as a straight edge, and at least a portion of the side of the second through hole (72) adjacent to the first through hole (71) is configured as a straight edge.

8. The fuse element for fuse according to claim 5, characterized in that: The second group of through holes includes a plurality of third through holes (81) arranged along the transverse direction (W) on the main body (6), the transverse dimension of the third through holes (81) being greater than the transverse dimension of the first through hole (71), wherein the second group of narrow diameters includes a narrow diameter formed between two adjacent third through holes (81).

9. The fuse element for a fuse according to claim 8, characterized in that: The side edge of the third through hole (81) adjacent to the other third through hole (81) is configured as an arc edge protruding toward the other third through hole (81).

10. A fuse, characterized in that: include: Housing (2); Two terminals (4) are respectively arranged at two opposite ends of the housing (2); A fuse (5) connected between the two terminals (4) in the housing (2), wherein the fuse (5) is the fuse according to any one of claims 1 to 9; Arc extinguishing medium is filled in the housing (2).

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