Melt, fuse and electric equipment

Abstract

The utility model discloses a melt, a fuse and electric equipment, the melt comprises at least two bodies, and a plurality of through holes are formed between the at least two bodies; the narrow path is connected between the at least two bodies, and the narrow path is formed between every two adjacent through holes; wherein the long axis distance of the through hole is a, the width of the through hole is phi, and a and phi meet the relational expression that a is larger than 1.2 phi. The long axis distance of the through hole is set to be at least 1.2 times of the width of the through hole, so that the temperature rise of the fuse can be greatly reduced by increasing the distance between the adjacent narrow diameters in the same row, the service life of the fuse is prolonged, and the fusing speed of the fuse is not sacrificed.

Description

Technical Field

[0001] The utility model relates to the technical field of fuses, in particular to a fuse element, a fuse and an electrical equipment. Background Art

[0002] A fuse refers to an electrical appliance that melts the fuse element by the heat generated by itself to disconnect the circuit when the current exceeds the specified value. A fuse is a kind of overcurrent protection device made based on the principle that after the current exceeds the specified value for a period of time, the fuse element is melted by the heat generated by itself, thereby disconnecting the circuit. Fuses are widely used in high and low voltage power distribution systems, control systems and electrical equipment. As short - circuit and over - current protectors, they are one of the most commonly used protection devices.

[0003] In the related art, the conflict between the fast breaking and the extended pulse life of fuses is becoming increasingly severe, and it is increasingly difficult to find a balance between the two. If we want to improve the breaking speed of traditional fuses, the general design idea is to reduce the cross - sectional area of the fuse element and lower the rated current of the fuse. This approach will cause an increase in heat loss and a sacrifice in life, and its application in scenarios such as fast charging of electric vehicles is limited. Summary of the Utility Model

[0004] The utility model aims to solve at least one of the technical problems existing in the prior art. For this purpose, the utility model provides a fuse element. The long - axis distance of the through - hole is set to be at least 1.2 times the width of the through - hole. In this way, the temperature rise of the fuse element can be greatly reduced, the life of the fuse can be extended, and the fusing speed of the fuse wire is not sacrificed by increasing the distance between adjacent narrow diameters in the same row.

[0005] The utility model further provides a fuse.

[0006] The utility model also provides an electrical equipment.

[0007] The fuse element according to the first - aspect embodiment of the utility model includes: at least two bodies, and a plurality of through - holes are formed between at least two of the bodies; narrow diameters, the narrow diameters are connected between at least two of the bodies, and the narrow diameters are formed between adjacent two of the through - holes; wherein, the long - axis distance of the through - hole is a, the width of the through - hole is φ, and a and φ satisfy the relational expression: a > 1.2φ.

[0008] According to the embodiment of the utility model, the long - axis distance of the through - hole is set to be at least 1.2 times the width of the through - hole. In this way, the temperature rise of the fuse element can be greatly reduced, the life of the fuse can be extended, and the fusing speed of the fuse wire is not sacrificed by increasing the distance between adjacent narrow diameters in the same row.

[0009] According to some embodiments of the utility model, φ satisfies the relational expression: 2mm < φ ≤ 6mm.

[0010] According to some embodiments of the present utility model, the size of the narrow path in the width direction of the melt is b, the thickness of the melt is d, and d and b satisfy the relational expression: d > b.

[0011] According to some embodiments of the present utility model, d and b respectively satisfy the relational expressions: 0.1 mm ≤ b ≤ 0.3 mm, 0.05 mm ≤ d ≤ 0.3 mm.

[0012] According to some embodiments of the present utility model, the number of the through holes is n, and the sum of the cross-sectional areas of the plurality of narrow paths in the length direction of the melt is s. Among them, n, s, d, and b satisfy the relational expression: 1.6 mm 2 <s = n * b * d < 1.75 mm 2 .

[0013] According to some embodiments of the present utility model, the sum of the cross-sectional perimeters of the plurality of narrow paths in the length direction of the melt is L. Among them, L, s, and d satisfy the relational expression: 21.25 mm < L = 2(s / d + d) < 21.40 mm.

[0014] The melt according to the second aspect embodiment of the present utility model includes: a housing; two end caps, the two end caps are arranged at both ends of the housing and form an accommodation space between the two end caps and the housing; at least one melt, at least one melt is arranged in the accommodation space, and both ends of at least one melt are electrically connected to the two end caps respectively.

[0015] According to some embodiments of the present utility model, the end cap includes: a baffle and a terminal, the terminal is arranged on the baffle, the baffle is arranged at both ends of the housing, the terminal is electrically connected to both ends of at least one melt, and a through hole is arranged on the terminal.

[0016] According to some embodiments of the present utility model, the fuse further includes: an arc extinguishing medium, and the arc extinguishing medium is arranged in the accommodation space.

[0017] The fuse according to the third aspect embodiment of the present utility model includes the fuse.

[0018] The additional aspects and advantages of the present utility model will be partially given in the following description, partially become obvious from the following description, or be understood through the practice of the present utility model. Description of the Drawings

[0019] The above and / or additional aspects and advantages of the present utility model will become obvious and easy to understand from the description of the embodiments in conjunction with the following drawings, wherein:

[0020] Figure 1is a schematic structural view of a fuse according to an embodiment of the present invention;

[0021] Figure 2 is an explosion view of a fuse according to an embodiment of the present invention;

[0022] Figure 3 is a schematic structural view of a fuse element according to an embodiment of the present invention;

[0023] Figure 4 is a front view of a fuse element according to an embodiment of the present invention.

[0024] Reference numerals:

[0025] 100, fuse;

[0026] 10, fuse element; 11, body; 12, narrow path; 13, through hole;

[0027] 20, end cap; 21, baffle; 22, terminal;

[0028] 30, housing;

[0029] 40, arc extinguishing medium. Detailed implementation manners

[0030] The embodiments of the present invention will be described in detail below. The embodiments described with reference to the drawings are exemplary. The embodiments of the present invention will be described in detail below.

[0031] Reference will be made below to Figures 1 - 4 describe a fuse element 10 according to an embodiment of the present invention, and the present invention further provides a fuse 100, and further, the present invention further provides an electrical equipment.

[0032] As Figure 3 and Figure 4 shown, the fuse element 10 according to the embodiment of the present invention includes: at least two bodies 11 and a narrow path 12. A plurality of through holes 13 are formed between at least two bodies 11. The narrow path 12 is connected between at least two bodies 11. A narrow path 12 is formed between two adjacent through holes 13.

[0033] The material of the fuse element 10 is such as silver or copper. Of course, it can also be a copper-silver alloy, a copper-silver composite material, etc.; the fuse element 10 is provided with a plurality of narrow paths 12 for interrupting when the current is too large. Through holes 13 are respectively arranged at the narrow paths 12 of the fuse element 10.

[0034] Among them, the formula for the fusing current allowed to pass when the fuse element 10 reaches the melting point:

[0035] I 2 =(Kt·M·S·τ) / ρ

[0036] Where S is the cross-sectional area; Kt is the comprehensive heat dissipation coefficient; τ is the temperature rise; M is the cross-sectional perimeter; ρ is the resistivity;

[0037] It can be known from the fusing current formula that the current-limiting ability of the fuse 100 is related to the temperature rise, structural design, and material during fusing.

[0038] By transforming the fusing current formula, the temperature rise can be obtained:

[0039] τ = I 2 ρ / (Kt · M · S)

[0040] Thermal time constant:

[0041] T = c · m / (A · Kt) = (c · S · γ) / (M · Kt)

[0042] Fusing time:

[0043] 4T = 4c · m / (A · Kt) = 4(c · S · γ) / (M · Kt)

[0044] Where S is the cross-sectional area; Kt is the comprehensive heat dissipation coefficient; A is the heat dissipation area; τ is the temperature rise; M is the cross-sectional perimeter; ρ is the resistivity; c is the specific heat capacity; γ is the density.

[0045] It can be known from the temperature rise formula that the temperature rise of the fuse link is positively correlated with the cross-sectional area and the cross-sectional perimeter; it can be known from the fusing time formula that the fusing time is positively correlated with the cross-sectional area and negatively correlated with the cross-sectional perimeter.

[0046] Among them, the major axis distance of the through hole 13 is a, and the width of the through hole 13 is φ. a and φ satisfy the relationship: a > 1.2φ. That is to say, the shape of the through hole 13 is an oblong hole, that is, the distance between adjacent narrow diameters 12 in the same row is greater than the width of the through hole 13. In this way, the temperature rise of the melt 10 can be greatly reduced and the service life of the fuse 100 can be extended by increasing the distance between adjacent narrow diameters 12 in the same row, without sacrificing the fusing speed of the fuse wire.

[0047] An organic glue layer is coated at the narrow diameter 12. The organic glue can be silicone rubber, but not limited to this, and it can also be other glues containing organic components. The thickness of the organic glue layer is not less than 0.3 mm, and the center position of the narrow diameter 12 is the coating point of the organic glue; because the organic glue has a certain elasticity, it can play a certain buffering role during the thermal expansion and contraction of the melt 10, making the narrow diameter 12 not easily break. In addition, the organic glue has the function of arc extinguishing, and the arc can be forced to extinguish by the gas generated by the high-temperature decomposition of the organic glue at the initial stage of the arc generation, reducing the difficulty of extinguishing the arc. The gas generated by the decomposition of the organic glue can improve the "sensitivity" of the fuse 100 when breaking small currents.

[0048] In addition, the number of times the designed fuse 100 can withstand current impact has been increased from 3,000 times of a conventional fuse to 40,000 times. Moreover, the highest temperature rise throughout the process is located at the housing 30, only 71°C, and the temperature rise of the terminal 22 is 40 - 50°C. After 40,000 times, the resistance value of the fuse 100 decreases, indicating that this current has not caused irreversible damage to the fuse element.

[0049] Therefore, the major axis distance of the through hole 13 is set to be at least 1.2 times the width of the through hole 13, so that the temperature rise of the fuse element 10 can be significantly reduced and the life of the fuse 100 can be extended by increasing the distance between adjacent narrow diameters 12 in the same row, without sacrificing the fusing speed of the fuse wire.

[0050] Among them, φ satisfies the relationship: 2mm < Φ ≤ 6mm. In this way, the width φ of the through hole 13 is set between 2mm and 6mm, which can ensure the strength at the narrow diameter 12 while not affecting the temperature rise, life, and fusing speed of the fuse element 10. For example, when the width φ of the through hole 13 is less than 2mm, the through hole 13 is relatively small, and thus the distance between the two ends of the through hole 13 is too close, which may cause arcing at both ends of the through hole 13 when the fuse element 10 melts. Another example is that when the width φ of the through hole 13 is greater than 2mm, the through hole 13 is relatively large, which makes the narrow diameter 12 longer, affecting the strength of the narrow diameter 12 and also the temperature rise, life, and fusing speed of the fuse element 10.

[0051] In addition, the dimension of the narrow diameter 12 in the width direction of the fuse element 10 is b, and the thickness of the fuse element 10 is d. d and b satisfy the relationship: d > b. That is to say, the thickness d of the fuse element 10 is greater than the distance b between the through holes 13, that is, the thickness at the narrow diameter 12 is greater than the width at the narrow diameter 12. In this way, while ensuring the normal fusing performance at the narrow diameter 12, the width at the narrow diameter 12 can be reduced, thereby increasing the distance between adjacent narrow diameters 12 in the same row, and further significantly reducing the temperature rise of the fuse element 10 and extending the life of the fuse, without sacrificing the fusing speed of the fuse wire.

[0052] Specifically, d and b respectively satisfy the relationships: 0.1mm ≤ b ≤ 0.3mm, 0.05mm ≤ d ≤ 0.3mm.

[0053] Among them, the number of through holes 13 is n, and the sum of the cross-sectional areas of multiple narrow diameters 12 in the length direction of the fuse element 10 is s. Among them, n, s, d, and b satisfy the relationship: 1.6mm 2 <s = n * b * d < 1.75mm 2 That is to say, the cross-sectional area s of the fuse element 10 is set between 1.6mm 2 and 1.75mm 2Thereby, the distance between adjacent narrow paths 12 in the same row can be effectively increased, and further, the temperature rise of the melt 10 can be significantly reduced, the service life of the fuse can be prolonged, and the fusing speed of the fuse wire is not sacrificed.

[0054] Similarly, the sum of the cross-sectional perimeters of multiple narrow paths 12 in the length direction of the melt 10 is L, where L, s, and d satisfy the relationship: 21.25 mm < L = 2(s / d + d) < 21.40 mm. The cross-sectional perimeter L of the melt 10 is set between 21.25 mm and 21.40 mm, thereby the distance between adjacent narrow paths 12 in the same row can be effectively increased, and further, the temperature rise of the melt 10 can be significantly reduced, the service life of the fuse can be prolonged, and the fusing speed of the fuse wire is not sacrificed.

[0055] Refer to Table 1 below:

[0056] Table 1. Results of the pre-arcing time and the maximum temperature of the melt after 40,000 pulses of the pulse current

[0057]

[0058] According to a second aspect embodiment of the present invention, a fuse 100 includes: a housing 30, two end caps 20, and at least one melt 10. The two end caps 20 are disposed at both ends of the housing 30, and a receiving space is formed between the two end caps 20 and the housing 30. At least one melt 10 is disposed in the receiving space, and both ends of at least one melt 10 are electrically connected to the two end caps 20 respectively. Thus, end caps 20 for electrical connection are provided at both ends of at least one melt 10, so that the fuse 100 can be disposed in an electrical device. When the electrical device is overloaded, the melt 10 melts, thereby achieving power-off of the electrical device.

[0059] In addition, at least one melt 10 is disposed in the receiving space. For example, the number of melts 10 can be two, so that when one melt 10 is damaged and fails, the other melt 10 can still work normally.

[0060] In addition, the end cap 20 further includes: a baffle 21 and a terminal 22. The terminal 22 is disposed on the baffle 21. The baffle 21 is disposed at both ends of the housing 30. The terminal 22 is electrically connected to both ends of at least one melt 10, and a through hole is provided on the terminal 22. Wherein, a closed receiving space can be formed by the baffle 21 and the housing 30, so that the melt 10 can be placed in the receiving space. Further, the baffle 21 and the housing 30 are connected by screws.

[0061] In addition, a terminal 22 is disposed on the baffle 21, and the terminal 22 is connected to both ends of the melt 10. The terminal 22 is made of a metal material and is used for electrical connection.

[0062] Further, a via hole is provided on the terminal 22, and the via hole is connected to the accommodation space, that is, the arc extinguishing medium 40 can be supplemented into the accommodation space through the via hole.

[0063] Wherein, the fuse element 10 is respectively electrically connected to the two terminals 22 by resistance welding.

[0064] In addition, the fuse 100 further includes: an arc extinguishing medium 40, which is disposed in the accommodation space. Among them, a large number of free electrons are contained in the narrow path 12 and the medium around the narrow path 12. When there is a sufficiently large applied voltage between the separated narrow paths 12 and the circuit current also reaches the minimum arcing current, intense ionization will occur to form an arc. An arc is a free gas with high temperature and high conductivity. It not only has a great destructive effect on the narrow path 12, but also prolongs the time for opening the circuit. Therefore, it is necessary to extinguish the arc, which is simply called arc extinguishing. There are various methods for arc extinguishing, and most of them use a certain gas or liquid to undertake the main arc extinguishing work, and these gases or liquids (even vacuum) are called the arc extinguishing medium 40.

[0065] Wherein, the arc extinguishing medium 40 can be sulfur hexafluoride, and sulfur hexafluoride has excellent arc extinguishing ability and insulation ability. Of course, the arc extinguishing medium 40 can also be a solid gas-producing material, and the gas generated by the solid gas-producing material under the action of the arc is used as the arc extinguishing medium 40.

[0066] The fuse 100 according to the third aspect embodiment of the present invention includes the fuse 100.

[0067] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0068] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "schematic embodiments", "examples", "specific examples", or "some examples", etc. means that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example.

[0069] Although embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A melt, characterized in that, Comprising: At least two bodies, with a plurality of through-holes formed between at least two of the bodies; A narrow path, the narrow path being connected between at least two of the bodies, and the narrow path being formed between adjacent two of the through-holes; wherein, The major axis distance of the through-hole is a, the width of the through-hole is φ, and a and φ satisfy the relationship: a > 1.2φ.

2. The melt according to claim 1, characterized in that, φ satisfies the relationship: 2 mm < φ ≤ 6 mm.

3. The melt according to claim 1, characterized in that, The dimension of the narrow path in the width direction of the melt is b, the thickness of the melt is d, and d and b satisfy the relationship: d > b.

4. The melt according to claim 2, characterized in that, d and b respectively satisfy the relationships: 0.1 mm ≤ b ≤ 0.3 mm, 0.05 mm ≤ d ≤ 0.3 mm.

5. The melt according to claim 3, characterized in that, The number of the through holes is n, and the sum of the cross-sectional areas of the plurality of narrow diameters in the length direction of the melt is s. Wherein, n, s, d, and b satisfy the relational expression: 1.6 mm 2 <s = n * b * d < 1.75 mm 2 .

6. The melt according to claim 5, characterized in that, The sum of the cross-sectional perimeters of a plurality of the narrow paths in the length direction of the melt is L, wherein L, s and d satisfy the relationship: 21.25 mm < L = 2(s / d + d) < 21.40 mm.

7. A fuse, characterized in that, Comprising: A housing; Two end caps, the two end caps being arranged at both ends of the housing and forming an accommodation space between the end caps and the housing; At least one melt according to any one of claims 1 - 6, at least one of the melts being arranged in the accommodation space, and both ends of at least one of the melts being electrically connected to the two end caps respectively.

8. The fuse according to claim 7, wherein, The end cap includes: a baffle and a terminal, the terminal being arranged on the baffle, the baffle being arranged at both ends of the housing, the terminal being electrically connected to both ends of at least one of the melts, and through-holes being arranged on the terminal.

9. The fuse according to claim 7, wherein, Further comprising: An arc extinguishing medium, the arc extinguishing medium being arranged in the accommodation space.

10. An electrical device, characterized in that, Comprising: A fuse according to any one of claims 7 - 9.

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