CN217719481U

CN217719481U - Tin-free welding overcurrent fuse

Info

Publication number: CN217719481U
Application number: CN202221477728.XU
Authority: CN
Inventors: 谭力; 王意志; 涂坚; 周志明; 程仁菊; 张琰斌; 黄星宇
Original assignee: Chongqing University of Technology
Current assignee: Chongqing University of Technology
Priority date: 2022-06-14
Filing date: 2022-06-14
Publication date: 2022-11-01
Anticipated expiration: 2032-06-14

Abstract

The utility model discloses a tin-free welding overcurrent fuse, which comprises a body, wherein the body comprises a hollow ceramic tube, two ends of the ceramic tube are respectively and tightly matched with metal caps, and each metal cap is provided with an inner hole; the fuse wire is arranged in the cavity of the ceramic tube, and two ends of the fuse wire are respectively connected to the metal caps; the metal caps at the left end and the right end are respectively and fixedly connected with conductive terminals; and an epoxy resin layer for sealing is arranged outside the body. The fuse wire of the utility model can effectively protect the circuit in the overcurrent protection current, fuse wires are fused with the metal copper matrix through the resistance spot welding technology, and the contact failure phenomenon is avoided; but also enhances the protection of the circuit.

Description

Tin-free welding overcurrent fuse

Technical Field

The utility model relates to a fuse technical field, concretely relates to solderless over-current fuse.

Background

Nowadays, fuses are widely applied to electronic and electric products such as circuit boards, chargers, household appliances and the like. As the fuse industry is continuously updated and iterated, the manufacturing process between enterprises is also continuously mature. For example, a conventional tubular fuse is generally produced by drawing, bonding, loading, soldering, crimping, and painting. The specific principle of the soldering process is that metal tin is heated to melt and then dripped into an opening of a copper cap (metal cap), and due to the fact that the melting point of tin is low, when tin liquid meets a cold copper cap, the tin liquid can be rapidly solidified, and therefore a fuse wire and the copper cap are connected. However, the soldering process also has many defects: 1) Tin is easy to evaporate while its melting point is low, and a large amount of tin sublimates to form tin smoke when tin is heated into liquid, and the smoke has strong pungent taste and is harmful to human body. 2) Auxiliary agents such as soldering flux, pine oil and the like are required to be added in the soldering process, and generally, the auxiliary agents occupy more stations on an SMT automatic machine and are not beneficial to processing and manufacturing. 3) Because the bonding force between the two molten tin is weaker when the molten tin is solidified on the copper cap, the molten tin can even naturally fall off to cause insufficient soldering and missing soldering when the copper cap has attachments, dust, grease and the like. These factors often cause the product yield to be seriously reduced, thereby affecting the production efficiency of the product.

Disclosure of Invention

The utility model discloses a solve the not enough and provide a solderless excess current fuse of above-mentioned technique, obtain the excess current fuse that the installation component is simple, rational in infrastructure, stable performance.

In order to achieve the purpose, the utility model provides the following technical proposal,

a tin-free welding overcurrent fuse comprises a body, and is characterized in that: the body comprises a hollow ceramic tube, metal caps are tightly matched with two ends of the ceramic tube respectively, and each metal cap is provided with an inner hole; the fuse wire is arranged in the cavity of the ceramic tube, and two ends of the fuse wire are respectively connected to the metal cap; the metal caps at the left end and the right end are respectively and fixedly connected with conductive terminals; and an epoxy resin layer for sealing is arranged outside the body.

Thus, the fuse wire of the utility model can effectively protect the circuit in the overcurrent protection current, fuse wires are fused with the metal copper matrix through the resistance spot welding technology, and the contact failure phenomenon is avoided; but also enhances the protection of the circuit.

Further: and the fuse wire and the metal cap are connected by spot welding. Fuse wires are fused with the metal copper matrix through resistance spot welding technology, and the phenomenon of poor contact is avoided.

And further: the fuse wire is formed by sequentially connecting a straight section, an obliquely upward section and an obliquely downward section, wherein the straight section is a straight section, and an arc-shaped transition section is arranged between the straight section and the obliquely upward section. The utility model discloses a shaping fuse of "it" font has certain tensile stress by welding back material inside, and the fuse can in time be broken after softening when overcurrent passes through to the protection efficiency has been strengthened.

Further: the inclined upper section is inclined upwards and extends obliquely upwards from one end of the straight section to the other end, and the inclined lower section extends obliquely downwards from the top end of the inclined upper section. Therefore, after the zigzag-shaped formed fuse wire is welded, a certain tensile stress exists in the material, and the fuse wire can be broken in time after being softened when an overload current passes through the fuse wire, so that the protection efficiency is enhanced.

Further: the conductive terminals at the left end and the right end adopt a crimping connection mode and are in interference fit with the metal cap.

Further: the inner diameter of the metal cap is smaller than the outer diameter of the ceramic tube, and the metal cap and the ceramic tube are in interference fit.

Further: the aperture of the inner hole of the metal cap is smaller than the inner diameter of the inner hole of the ceramic tube.

Further: the metal cap is made of copper.

The fuse wire is made of magnesium-aluminum alloy.

The utility model discloses a no tin welds overcurrent fuse has following characteristics:

1. the utility model can effectively protect the circuit in the overcurrent protection current, fuse wires are fused with the metal copper matrix through resistance spot welding technology, and the contact failure phenomenon is avoided;

2. the shaped fuse wire of the utility model has a certain strengthening effect, the shaped fuse wire has a certain tensile stress in the welded material, and the fuse wire can be broken in time after being softened when the overload current passes through, thereby enhancing the protection efficiency;

3. according to many times of experiments, the utility model discloses the fuse has especially effectively shortened the time in welding process, has improved production efficiency, has improved workshop operation environment simultaneously, has effectively saved manufacturing cost.

Drawings

FIG. 1 is a structural assembly diagram of a fuse

FIG. 2 is a flow chart of fuse fabrication;

fig. 3 is a schematic diagram of a fuse structure.

In the figure, 1-body, 2-ceramic tube, 3-metal cap, 4-fuse, 5-conductive terminal, 6-epoxy layer.

Detailed Description

The present invention will be described in detail with reference to the following embodiments.

A tin-free welding overcurrent fuse comprises a body 1, wherein the body 1 comprises a hollow ceramic tube 2, two ends of the ceramic tube 2 are respectively provided with a metal cap 3 in close fit (interference fit), each metal cap 3 is provided with an inner hole, and the metal caps 3 are usually made of copper and have excellent conductivity and oxidation resistance; the fuse wire 4 is a metal fuse wire, the specific material can be magnesium-aluminum alloy wire, the fuse wire is arranged in the cavity of the ceramic tube 2, and two ends of the fuse wire are respectively connected to the metal cap 3; between fuse 4 and metal cap 3, adopt the spot welding to be connected, specifically be through an intermediate frequency alternating current resistance spot welder,

weld

4 and 3 links of metal cap of fuse, wherein the alternating current resistance spot welder is adjustable, the utility model provides a spot welding electrode pressure is 3500 newtons (N), welding current 1600 amperes (A), and the welding time is 110 milliseconds (ms). The metal caps 3 at the left and right ends are respectively and fixedly connected with conductive terminals 5, and the conductive terminals 5 at the left and right ends are tightly matched (in interference fit) with the metal caps 3 in a compression joint mode; and after being pressed, the conductive terminals 5 at the left end and the right end are respectively communicated with the fuse 4 through the metal cap 3, and the fuse 4 in the body 1 is connected with an external circuit. The epoxy resin layer 6 is a sealing layer arranged outside the body 1 to play a role of sealing, and the flowing epoxy resin is attached to the sealing layer formed outside the ceramic tube 2 on the whole body 1, so that the fuse of the utility model is wrapped in the epoxy resin layer 6, and the sealing performance of the whole fuse body 1 is improved through the sealing effect of the epoxy resin layer 6; the flowable epoxy resin may be disposed by painting.

The utility model discloses the 3 internal diameters of metal cap who chooses slightly are lighter than 2 external diameters of ceramic pipe for interference fit between the two has certain pressure to be difficult for separating after the joint. Meanwhile, the aperture of the opening of the metal cap 3 is smaller than the inner diameter of the inner hole of the ceramic tube 2, so that a fuse wire in the ceramic tube 2 is attached to the tube wall of the ceramic tube 2, and the design is needed, so that the fuse wire 4 is not easy to quickly lose generated heat through the tube wall and is easier to fuse when overcurrent occurs; the inner diameter of the conductive terminal 5 is slightly smaller than the outer diameter of the metal cap 3, and a certain binding force is generated after the conductive terminal and the metal cap are in interference fit.

As shown in fig. 3, the fuse 4 of the present invention is made of magnesium aluminum alloy, and has a substantially zigzag shape, and is formed by sequentially connecting a straight section 41, an obliquely upward section 42 and an obliquely downward section 43, wherein the straight section 41 is a straight section, an arc transition section 44 is provided between the straight section 41 and the obliquely upward section 42, the obliquely upward section 42 is inclined upward, and extends obliquely upward from one end of the straight section 41 to the other end, and the obliquely downward section 43 extends obliquely downward from the top end of the obliquely upward section 42, thereby substantially forming a zigzag structure. The utility model discloses a fuse 4 is earlier with the fuse shaping of bending, cuts off the wire rod after the welding again and goes up the unnecessary part of straight section 41 and slant hypomere 43 for 4 both ends of fuse (straight section 41 and slant hypomere 43) can be affiliated to respectively at 2 both ends of ceramic pipe, and the mode through resistance spot welding at last fixes the fuse on metal cap 3. After the zigzag-shaped formed fuse wire 4 is welded, a certain tensile stress is formed in the material, and the fuse wire can be broken in time after being softened when an overload current passes through the fuse wire, so that the protection efficiency is enhanced.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the technical solutions, and those skilled in the art should understand that those modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all should be covered in the scope of the claims of the present invention.

Claims

1. A tin-free over-current fuse comprises a body (1), and is characterized in that: the body (1) comprises a hollow ceramic tube (2), metal caps (3) are respectively tightly matched at two ends of the ceramic tube (2), and each metal cap (3) is provided with an inner hole; the fuse wire (4) is arranged in the cavity of the ceramic tube (2), and two ends of the fuse wire are respectively connected to the metal cap (3); the metal caps (3) at the left end and the right end are respectively and fixedly connected with conductive terminals (5); an epoxy resin layer (6) for sealing is arranged outside the body (1).

2. A solderless over current fuse in accordance with claim 1, wherein: the aperture of the inner hole of the metal cap (3) is smaller than the inner diameter of the inner hole of the ceramic tube (2).

3. A solderless over current fuse in accordance with claim 1 or 2 wherein: the fuse wire (4) is formed by sequentially connecting a straight section (41), an obliquely upward section (42) and an obliquely downward section (43), wherein the straight section (41) is a straight section, and an arc-shaped transition section (44) is arranged between the straight section (41) and the obliquely upward section (42).

4. A solderless overcurrent fuse as claimed in claim 3, wherein: the obliquely upward section (42) extends obliquely upward from one end of the straight section (41) to the other end, and the obliquely downward section (43) extends obliquely downward from the top end of the obliquely upward section (42).

5. A solderless over current fuse in accordance with claim 4 wherein: the fuse wire (4) and the metal cap (3) are connected by spot welding.

6. A solderless over current fuse in accordance with claim 4 wherein: the conductive terminals (5) at the left end and the right end adopt a compression joint connection mode and are in interference fit with the metal cap (3).

7. A solderless over current fuse in accordance with claim 1 or 2 wherein: the inner diameter of the metal cap (3) is smaller than the outer diameter of the ceramic tube (2), and the metal cap and the ceramic tube are in interference fit.

8. A solderless over current fuse in accordance with claim 1 or 2 wherein: the metal cap (3) is made of copper.

9. A solderless over current fuse in accordance with claim 3 wherein: the fuse wire (4) is made of magnesium-aluminum alloy.