KR20120026201A - Repeatable fuse - Google Patents

Abstract

The present invention relates to a repeatable fuse having a precise operating temperature characteristics and rated current characteristics for various operating temperatures and rated currents, which can be manufactured compactly,
A repeatable fuse according to an embodiment of the present invention includes a shape memory alloy spring and a bias spring corresponding to the shape memory alloy spring, wherein the shape memory alloy spring has a wire diameter of 0.15 mm to 0.50. It is formed into a coil shape that is mm, and the number of wire turns is 3.5 to 7.0.

Description

Repetitive Fuses {REPEATABLE FUSE}

The present invention relates to a repetitive fuse, and more particularly, to a repetitive fuse having a precise operating temperature characteristic and a rated current characteristic for various operating temperatures and rated currents, and which can be manufactured compactly.

In general, all electrical and electronic products that use electricity are always inherent in accidents caused by abnormal overcurrent in the circuit or overheating caused by external overheating. Conventionally, in order to prevent this, a disposable fuse formed of a material that is melted and broken by heat generated as an electric current when an overcurrent flows is used. Disposable fuses, however, are inexpensive but cannot be reused and must be replaced with new ones. To solve this problem, a bimetal thermal switch in which dissimilar metal plates with different thermal expansion coefficients are used instead of a single-use fuse, but the bimetal thermal switch not only functions as a contact point but also has a large operating deviation according to temperature and a separate switch such as a limit switch. There is a problem that the device is required.

Although a polymer fuse using a special polymer has been developed, a polymer fuse also has a problem of fire hazard due to an explosion when a sudden change in voltage and current occurs due to a decrease in the stability of a material according to a chemical product. Moreover, polymer fuses are less stable and durable, and may cause an emergency situation due to a slow reaction time.

Meanwhile, in recent years, electronic devices are mainly required for fuses which can be surface-mounted according to surface mounting of printed circuit boards. However, since the fuse according to the prior art requires a temperature of about 270 degrees Celsius or more for soldering in the surface mount process, the fuse is melted and thus surface mount is impossible. Of course, bimetal thermal switches can solve this problem, but surface mounting is difficult due to excessive component size and the possibility of deterioration due to soldering temperatures.

In order to solve this problem, a shape memory alloy fuse using an elastic member, such as a shape memory alloy, which can be used continuously and is surface mounted has been developed. Shape memory alloys provide reliable fuses with low temperature variations.

However, since the design dimensions such as the wire diameter and the number of turns of the shape memory alloy spring wire constituting the shape memory alloy fuse and the bias wire providing the corresponding tension are not established, many experiments are carried out during actual manufacturing. There is a mistake. Therefore, the manufacturing time is increased, the manufacturing cost by the material used in the experiment is increased, there is a disadvantage that the productivity of the product is reduced.

The present invention provides a repeatable fuse that is made compact and can be used repeatedly.

In addition, the present invention provides a repetitive fuse having an accurate operating temperature characteristics and rated current characteristics for various operating temperatures and rated currents.

In addition, the present invention provides a repetitive fuse that can shorten the manufacturing time and manufacturing cost, thereby improving productivity.

Repetitive fuse according to an embodiment of the present invention,

A repetitive fuse comprising a shape memory alloy spring and a bias spring corresponding to the shape memory alloy spring, wherein the shape memory alloy spring is formed in a coil shape having a wire wire diameter of 0.15 mm to 0.50 mm, and the number of wire turns 3.5 to 7.0.

It is preferable that the shape memory alloy spring has a wire diameter of 0.20 mm to 0.40 mm and a wire turn number of 4.0 to 6.5.

The outer diameter of the shape memory alloy spring may be formed to a size of 7.0 to 8.5 times the wire wire diameter.

The average pitch spacing of the shape memory alloy spring is preferably 1.0 mm to 1.5 mm.

The wire diameter of the bias spring preferably has a length of 60% to 65% of the shape memory alloy spring wire diameter.

The wire diameter of the bias spring is 0.10 mm to 0.30 mm.

The number of wire turns of the bias spring is larger than the number of wire turns of the shape memory alloy spring, and is 4.0 to 7.5.

The bias spring preferably has a wire diameter of 0.15 mm to 0.25 mm and a number of wire turns of 5.0 to 6.0.

The average pitch of the bias spring is preferably 1.0mm to 1.5mm.

The bias spring height is preferably formed in a size of 120% to 125% of the height of the shape memory alloy spring.

The shape memory alloy spring is preferably an alloy containing nickel (Ni) and titanium (Ti).

The shape memory alloy spring may include at least one of cobalt (Co), molybdenum (Mo), tungsten (W), and chromium (Cr).

The bias spring is made of a SUS stainless steel material, and may be manufactured by plating at least one of Ni, Cu, Ag, Au, and Sn on the stainless steel.

According to the embodiments of the present invention as described above, it is possible to provide a repeatable fuse that can be manufactured in a small size while maintaining the operating characteristics even during repeated use.

In addition, the present invention can provide a repeating fuse having an accurate operating temperature characteristics and rated current characteristics for various operating temperatures and rated currents.

In addition, the present invention can provide a repetitive fuse that can improve the productivity by reducing the manufacturing time and manufacturing cost by presenting the optimum design dimensions for the shape memory alloy spring and the bias spring of the repetitive fuse.

1 is an exploded perspective view showing a repeating fuse according to an embodiment of the present invention;
2 and 3 is an operating state diagram showing the operation of the repetitive fuse according to an embodiment of the present invention,
4 is a cross-sectional view showing a portion of a repetitive fuse according to an embodiment of the present invention;
5 is a view showing the operation characteristics of the repetitive fuse according to the wire diameter (Φ1) of the shape memory alloy spring,
6 is a view showing the operation characteristics of the repetitive fuse according to the number of wire turns (T1) of the shape memory alloy spring,
7 is a view showing the operating characteristics of the repetitive fuse according to the wire wire diameter (Φ 2) of the bias spring,
FIG. 8 is a diagram illustrating an operating characteristic of the repetitive fuse according to the wire turn number T2 of the bias spring.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention; First, it should be noted that the same components or parts among the drawings denote the same reference numerals whenever possible. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted so as not to obscure the subject matter of the present invention.

1 is an exploded perspective view showing a repetitive fuse according to an embodiment of the present invention, Figures 2 and 3 is an operating state diagram showing the operation of the repetitive fuse according to an embodiment of the present invention, Figure 4 is A cross-sectional view of a portion of a repeatable fuse according to an embodiment.

1 to 4, the repetitive fuse according to the exemplary embodiment of the present invention is insulated from the housing 100, the first lead terminal 200 disposed on one side of the housing, and the housing. A second lead terminal 300 disposed on the other side of the housing, a spindle 400 disposed inside the housing and electrically connected to the first lead terminal and intermittently interposed between the second lead terminals; A shape memory alloy spring 510 and a bias spring 520 are installed inside the housing and connected to the spindle, and are elastic members for intermittently connecting the second lead terminal 300 and the spindle.

The housing 100 is a box shape having an inner space and extending in the longitudinal direction, and accommodates and protects the spindle 400, the shape memory alloy spring 510, and the bias spring 520. Since the housing 100 may be electrically connected to the first lead terminal 200, the housing 100 may be formed of a conductive material. Of course, depending on the embodiment it may be formed of a non-conductive material. The housing 100 may have a cross section perpendicular to the longitudinal direction, and may have a circular, elliptical, or polygonal shape, such as a circular box, elliptical box, or polygonal box. In this embodiment, a circular box is illustrated as shown in FIG.

In addition, the engaging jaw 120 protruding in the inner horizontal direction at a predetermined position on the inner circumferential surface of the housing 100 may be formed to support the shape memory alloy spring 510. A shape memory alloy spring 510 and a bias spring 520 are installed between the locking jaw 120 and the other end of the housing 100 (an end at which the second lead terminal 300 is disposed). At this time, the design dimensions of the shape memory alloy spring 510 and bias spring 520 is precisely controlled. Detailed description thereof will be described later.

The first lead terminal 200 is a means that receives an external power source or is connected to the power source, and includes a conductive material. The first lead terminal 200 is provided at one side of the housing 100. In this embodiment, the first lead terminal 200 is disposed at one end of the housing 100 having a circular box shape. The first lead terminal 200 is electrically connected to the shape memory alloy spring 510 or the bias spring 520 through the housing 100 or a separate connection member (not shown). It is electrically connected with. For example, when the housing 100 is made of a conductive material and the shape memory alloy spring 510 or the bias spring 520 is in contact with one side of the inner surface of the housing 100 or the locking jaw 120, the housing 100 may be electrically connected to the housing 100. Will be connected. The shape memory alloy spring 510 or the bias spring 520 may be electrically connected to one side of the spindle 400. The first lead terminal 200 is provided in the shape of a rod in this embodiment, but is not limited thereto, and may be any shape that can be electrically connected.

The second lead terminal 300 is a means for electrical connection. For example, the second lead terminal 300 transmits a current applied from the first lead terminal 200 to the electronic device and includes a conductive material. The second lead terminal 300 is disposed to be spaced apart from the first lead terminal 200 by a predetermined distance. In the present embodiment, the second lead terminal 300 is disposed in a direction opposite to one end where the first lead terminal 200 is formed in the housing 100 having a circular box shape. It is formed at the other end located. In this case, the second lead terminal 300 may be disposed in a form inserted through the bottom of the housing, but is not limited thereto and may be spaced apart from the bottom. That is, any position may be used as long as the spindle 400 moves to connect or short-circuit with the second lead terminal 300.

The second lead terminal 300 is connected to or short-circuited with the first lead terminal 200 by the spindle 400. Since the second lead terminal 300 is electrically connected to the first lead terminal 200 through the spindle 400, the second lead terminal 300 is insulated from the housing 100 electrically connected to the first lead terminal 200. To this end, one side of the housing 100 on which the second lead terminal 300 is disposed is formed as an opening shape so as to space the housing 100 and the second lead terminal 300 or the second lead terminal 300 passes. An insulation may be coated on the surface of the housing 100.

The spindle 400 is a means for connecting or shorting the first lead terminal 200 and the second lead terminal 300 and is provided in the housing 100. The spindle 400 may be provided in the form of a shaft extending in the longitudinal direction like the housing 100 extending in the longitudinal direction. Spindle 400 may be formed in a cross section perpendicular to the longitudinal direction in a circular, elliptical, polygonal, etc., preferably formed in the same shape as the cross-sectional shape of the housing 100. In this embodiment, as shown in Figure 1, it is formed in a cylindrical shape formed along the housing 100 of the circular box shape. The spindle 400 may be electrically connected to the first lead terminal 200 by the shape memory alloy spring 510, and is preferably formed of a conductive material. As shown in FIG. 2 and FIG. 3. The spindle 400 is intermittently intersected with the second lead terminal 300 while reciprocating the inside of the housing 100 in the longitudinal direction by the stretching movement of the shape memory alloy spring 510 and the bias spring 520. Are connected (see FIG. 2) or shorted (see FIG. 3). Therefore, as the spindle 400 is connected to or shorted with the second lead terminal 300, the first lead terminal 200 and the second lead terminal 300 are connected or short-circuited. The spindle 400 has a support 410 that can support the shape memory alloy spring 510 or the bias spring 520 on at least a portion of the side surface to be connected to the shape memory alloy spring 510 or the bias spring 520. Can be. The support part 410 may protrude in a direction perpendicular to the axis direction of the spindle 400 on the side of the spindle 400. The support part 410 may be continuously formed along the circumference of the spindle 400 side, or may be discontinuously formed on the spindle 400 side. That is, as long as the spindle 400 can be connected to the shape memory alloy spring 510 or the bias spring 520, any form can be used.

The shape memory alloy spring 510 and the bias spring 520 are means for connecting or shorting the second lead terminal 300 and the spindle 400. They are disposed inside the housing 100, and are arranged to extend or compress in the longitudinal direction of the housing 100. Shape memory alloy spring 510 is connected to one side of the housing 100, in this embodiment is connected to the locking step 120 of the housing 100. The bias spring 520 is connected to the spindle 400 or is connected to the support 410 of the spindle and electrically connected thereto. In the present exemplary embodiment, the shape memory alloy spring 510 is disposed on the left side of the spindle 400 and the bias spring 520 is disposed on the right side. However, the springs 510 and 520 may be disposed by changing their positions. It may be. That is, the bias spring 520 may be disposed on the left side of the pins 400, and the shape memory alloy spring 510 may be disposed on the right side of the fins 400. In this case, the function that is turned on in the normal state becomes a repetitive fuse that is turned off in the normal state.

The above-described embodiment merely describes an embodiment to which the design dimensions of the shape memory alloy spring 510 and the bias spring 520 to be described below can be applied, and limits the embodiment to which the design dimensions of the present invention can be applied. It is not.

The inventors of the present invention, for the repetitive fuse having a shape memory alloy spring, the shape memory alloy spring 510 and the bias spring 520 are manufactured under various design conditions to show the shape memory exhibiting accurate operating temperature characteristics and rated current characteristics Design dimensions of alloy spring 510 are presented. In addition, the design dimensions of the bias spring 520 corresponding to the design conditions of the shape memory alloy spring is presented. This will be described below.

Shape memory alloy spring 510 may be made of an alloy containing nickel (Ni) and titanium (Ti), to produce a spring having three different operating temperature characteristics largely by the composition ratio change as shown in Table 1 below. Can be. Of course, this is only an example, and the operating temperature is not limited thereto. In addition, a spring having various operating temperature characteristics may be manufactured by including at least one of cobalt (Co), molybdenum (Mo), tungsten (W), and chromium (Cr) in a predetermined ratio.

Ni / Ti composition ratio according to operating temperature Ni / Ti composition ratio Operating temperature 54.8 / 45 115 degrees (± 5 degrees) 55.32 / 44.6 95 degrees (± 5 degrees) 55.34 / 44.6 75 degrees (± 5 degrees)

The design dimensions of the shape memory alloy spring 510 and the bias spring 520 will be described with reference to FIG. 4. In the present specification, 'wire wire diameter (Φ1, Φ2)' refers to the diameter of the wires (when the square spring, the vertical length) of the wires of the spring (510, 520), 'wire turn number (T1, T2)' is the coil-shaped spring It means the number of revolutions (510, 520). In addition, the average pitches P1 and P2 mean an average value of the spacing between the coil-shaped springs (the spacing between the spiral shapes), and the heights H1 and H2 mean the entire lengths of the springs 510 and 520. . 'Outer diameters OD1 and OD2' mean diameters of circles formed by the springs 510 and 520.

The shape memory alloy spring 510 allows the wire diameter Φ 1 to be formed in a coil shape of 0.15 mm to 0.50 mm, and the number of wire turns T1 is 3.5 to 7.0. This makes it possible to exhibit operating temperature characteristics and rated current characteristics. Preferably, when the wire diameter (Φ1) is 0.20mm to 0.40mm, and the number of wire turns (T1) is 4.0 to 6.5, it was confirmed by experiment to exhibit more accurate operating temperature characteristics and rated current characteristics. On the other hand, the shape of the coil may be a variety of shapes, such as circular or polygonal, it is preferable to be formed in a shape corresponding to the shape inside the housing 100 for the convenience of manufacturing.

The outer diameter OD1 of the shape memory alloy spring is formed to be approximately 7.0 to 8.5 times the wire diameter Φ1. For example, when the wire diameter Φ1 is 0.25 mm, the outer diameter OD1 of the spring is about 1.75 mm, and when the wire wire diameter Φ1 is about 0.30 mm, the outer diameter OD1 of the spring is about 2.50 mm. To be In addition, when the wire wire diameter Φ 1 is 0.35mm, the outer diameter OD1 of the spring is about 3.00mm. This ensures a minimum radius of curvature (3 to 5 times the wire diameter) required for processing the shape memory alloy spring 510, and provides space and housing for expansion (expansion rate of about 10% or more) after heat treatment. It is possible to secure a space for assembling work.

In order to secure proper elasticity of the shape memory alloy spring 510, the average pitch spacing P1 of the shape memory alloy spring is set to be 1.00 mm to 1.50 mm. When the average pitch interval P1 is greater than 1.50 mm or less than 1.00 mm, elasticity suitable for use as a repetitive fuse does not occur. When the average pitch interval P1 is 1.00 mm to 1.50 mm, an optimum elastic force is generated. Was confirmed experimentally.

The average pitch interval P1 and the number of turns T1 may be determined, and the height H1 of the spring 510 may be determined. For example, when the average pitch interval P1 is 1.50 mm and the number of turns T1 is 5.0, both ends of the spring 510 overlap, so that the effective number of turns T1 is 3.0 so that the effective number of turns T1 is 3.0. The height H1 is 1.50 mm x 3.0 = 4.50 mm.

The shape memory alloy spring 510 is manufactured by designing the wire wire diameter Φ 1, the number of turns T 1, the outer diameter OD 1, the pitch P 1, and the height H 1 within the ranges set forth above.

The bias spring 520 is conditioned to obtain the design dimensions of the shape memory alloy spring 510 and the corresponding tension.

After determining the design dimensions of the shape memory alloy spring 510 within the above range, and repeated experiments on the conditions of the bias spring 520 to generate a corresponding tension, the wire diameter of the bias spring 520 on average When (Φ 2) is approximately 60% to 65% of the wire diameter (Φ 1) of the shape memory alloy spring 510, accurate operating characteristics of the repetitive fuse can be realized, and the number of wire turns of the bias spring 520 ( T2) was confirmed to be able to implement the correct operating characteristics by manufacturing 0.5 turns larger than the average number of wire turns (T1) of the shape memory alloy spring 510.

More specifically, the bias spring 520 is made of a SUS-based stainless steel (for example, SUS304), and at least any one of Ni, Cu, Ag, Au, and Sn on the stainless steel to adjust electrical resistance. One can be used by plating. In addition, the wire diameter of the bias spring (Φ2) is formed from 0.10mm to 0.30mm. In addition, the bias spring 520 is formed in a shape corresponding to the coil shape of the shape memory alloy spring 510, the wire turn number (T2) is formed larger than the wire turn number (T1) of the shape memory alloy spring. . Preferably, it is larger than the number of wire turns T1 of the shape memory alloy spring but is formed with a number of turns in the range of 4.0 to 7.5. More preferably, when the wire diameter (Φ2) of the bias spring 520 is 0.15mm to 0.25mm, and the number of wire turns is 5.0 to 6.0, it was confirmed by experiment that the accurate operating temperature characteristics and rated current characteristics.

The outer diameter OD2 of the bias spring 520 is preferably formed to have a size similar to the outer diameter OD1 of the shape memory alloy spring for the same reason as that of the shape memory alloy spring 510.

In addition, in order to secure the proper elasticity of the bias spring 520, the pitch interval (P2) is 1.00mm to 1.50mm, the height (H2) is approximately 20% to the height (H1) of the shape memory alloy spring It is preferable to form about 25% high.

As described above, the wire wire diameter Φ1 of the shape memory alloy spring 510, the number of turns T1, the outer diameter OD1, the pitch P1, and the height H1 and the wire wire diameter Φ2 of the bias spring 520. By suitably combining the number of turns T2, the outer diameter OD2, the pitch P2, and the height H2, a repeatable fuse having a rated current between 2A and 20A can be manufactured.

In addition, when the shape memory alloy spring 510 is manufactured using a shape memory alloy having a different transition temperature, wire wire diameters Φ1 and Φ2 and the number of turns T1 and T2 of the shape memory alloy springs and the bias springs 510 and 520 may be used. ), The outer diameter OD1, OD2, the pitch (P1, P2) and the height (H1, H2) without changing the repeatable fuse can be manufactured at various temperatures, such as 75 degrees, 95 degrees, 115 degrees. That is, the change of the operating temperature may be implemented by changing the composition of the shape memory alloy, and the wire diameter Φ 2 of the bias spring 520 corresponding thereto is designed slightly different for each operating temperature. For example, 95 degrees can use about 5-12% less wire diameter compared to 75 degrees, 115 degrees can use about 5-12% reduced wire diameter than 95 degrees.

By using the shape memory alloy spring 510 and the bias spring 520 of the design dimensions as described above, a very small repetitive fuse having a diameter of about 1.5 mm and a length of about 4 mm in length (in the case of a square) is manufactured. can do. Even in the case of a large current capacity having a rated current of 20 A, a small sized repeatable fuse having a diameter of about 4.5 mm and a length of about 10 mm or less can be produced.

The technical meaning of the above-mentioned numerical values will be described through the following experimental examples. In the following experimental examples, '◎' means 'excellent', and means that it works very well near the operating temperature center value. In addition, "○" means "good", the deviation in the operating temperature range occurs within ± 5 degrees, which means that it operates relatively well near the center value. '△' means 'normal', which means that the range deviation of the operating temperature is rather large and the rated current is unstable, but it can be used. '×' means 'inoperation', which means that the operating temperature is too high or not working at all. The rated current is a current capacity that can flow stably at room temperature for a long time. The breaking current at which the actual fuse operates (if the fuse is not a repeated fuse) is about 2 to 3 times the rated current.

Experimental Example 1

The wire diameter (Φ1) and the number of turns (T1) of the shape memory alloy spring 510 having an operating temperature characteristic of 75 degrees (± 5 degrees) were repeated several times, and the results as shown in [Table 2] below. Could get

Experiment of manufacturing repeated fuse with small capacity of rated current 2A Wire diameter (Φ1) Turns (T1) Operating temperature test result Rated current 0.20mm 3.5 ○ 2A available 0.20mm 4.0 ◎ 2A available 0.20mm 4.5 ○ 2A available 0.15mm 3.0 × - 0.15mm 3.5 △ 2A possible, unstable 0.15mm 4.0 ○ 2A possible, unstable 0.15mm 4.5 △ 2A possible, unstable Less than 0.15mm  Inability to process or almost no elasticity with spring

According to the above [Table 2], when the wire diameter (Φ1) of the shape memory alloy spring 510 is less than 0.15mm, it can be seen that the spring elasticity is almost impossible even if the spring processing is impossible or processed.

When the wire diameter (Φ1) is 0.15mm and the number of turns (T1) is 3.5 and 4.5, the range deviation of the operating temperature occurs slightly, and the rated current is unstable, but the diameter is about 1.5mm and the length is about 4mm. It can be seen that it can be used ('ordinary') even when manufactured in a small size.

When the wire diameter Φ 1 is 0.15 mm and the number of turns T 1 is 4, the deviation of the operating temperature range occurs in the range of ± 5 degrees, and it operates relatively well near the center value ('good'). Able to know.

When wire diameter Φ1 is 0.20mm, it can be used at rated current 2A, and when the number of turns T1 is 3.5 and 4.5, it operates 'good', and when the number of turns T1 is 4.0 It can be seen that it works very well ('good') near the temperature center value.

Experimental Example 2

The wire memory diameter (Φ1) and the number of turns (T1) of the shape memory alloy spring 510 having an operating temperature characteristic of 95 degrees (± 5 degrees) was repeated several times, and the results as shown in [Table 3] below. Could get

Experiment of manufacturing repeated fuse with medium capacity of rated current 10A Wire diameter (Φ1) Turns (T1) Operating temperature test result Rated current 0.35mm 5.0 ○ 10A available 0.35mm 5.5 ◎ 10A available 0.35mm 6.0 ○ 10A available 0.40mm 5.5 △ 10 A or more, unstable 0.40mm 6.0 ○ 10 A or more, unstable 0.40mm 7.0 △ 10 A or more, unstable

According to the above [Table 3], when the wire diameter (Φ1) of the shape memory alloy spring 510 is 0.35mm, it can be seen that it can be used for the rated current 10A.

In particular, when the wire diameter (Φ1) is 0.35mm, the number of turns (T1) is 5.0, 6.0, it can be seen that it works 'good'. In addition, when the wire diameter Φ 1 is 0.35 mm and the number of turns T1 is 5.5, it can be seen that it works 'excellent'.

On the other hand, when the wire diameter (Φ1) is 0.40mm, it can be seen that it can be used unstable for the rated current 10A or more.

In particular, when the wire diameter (Φ1) is 0.40mm, and the number of turns (T1) is 5.5, 7.0, the operation is 'normal', and when the number of turns (T1) is 6.0, it can be seen that the operation is 'excellent'. have.

Experimental Example 3

The wire memory diameter (Φ1) and the number of turns (T1) of the shape memory alloy spring 510 having an operating temperature characteristic of 115 degrees (± 5 degrees) was repeated several times, and the results as shown in Table 4 below. Could get

Experiment of manufacturing repeated fuse with large capacity of rated current 20A Wire diameter (Φ1) Turns (T1) Operating temperature test result Rated current 0.40mm 6.0 ○ 20A available 0.40mm 6.5 ◎ 20A available 0.40mm 7.0 ○ 20A available 0.50mm 6.5 △ 20A or more, unstable 0.50mm 7.0 ○ 20A or more, unstable 0.50mm 7.5 △ 20A or more, unstable More than 0.50mm Can be manufactured, but the part size exceeds 4.5mm in diameter and 10mm in length

According to the above [Table 4], when the wire diameter Φ1 of the shape memory alloy spring 510 exceeds 0.50 mm, spring processing is possible and an effective rated current can be obtained, but the size of the manufactured fuse is It is difficult to miniaturize parts because the diameter (length in the case of a rectangle, the length of the width and length) exceeds 4.5mm and the length exceeds 10mm.

On the other hand, when the wire diameter (Φ1) is 0.40mm, it can be seen that can be used for the rated current 20A.

In particular, when the wire diameter (Φ1) is 0.40mm, the number of turns (T1) is 6.0, 7.0, it can be seen that it works 'good'. In addition, when the wire diameter Φ 1 is 0.40 mm and the turn number T 1 is 6.5, it can be seen that it works 'excellent'.

On the other hand, when the wire diameter (Φ1) is 0.50mm, it can be seen that it can be used unstable for the rated current 20A or more.

In particular, when the wire diameter (Φ1) is 0.50mm, and the number of turns (T1) is 6.5, 7.5, the operation is 'normal', and when the number of turns (T1) is 7.0, it can be seen that the operation 'excellent'. have.

In the case of the bias spring 520, when the design dimension of the shape memory alloy spring 510 is determined, it is designed to have a tension corresponding to the tension, and as a design dimension of the bias spring 520, the spring outer diameter OD2 is It is less than or equal to the outer diameter OD1 of the shape memory alloy spring 510 for assembly with the housing 100. Further, since the basic assembly state is to exert the tension of the bias spring to suppress the shape memory alloy spring, the spring turn number Φ 2 should be somewhat higher than the turn number T 1 of the shape memory alloy spring 510. Under such conditions, the changeable range of the wire diameter .phi.2 of the bias spring 520 is narrowed.

5 to 8 illustrate wire conditions of the shape memory alloy spring 510 and the bias spring 520 for the manufacture of a repetitive fuse having the optimum operating characteristics or manufacturing based on the experimental examples.

5 is a view showing the operation characteristics of the repetitive fuse according to the wire diameter (Φ1) of the shape memory alloy spring.

In FIG. 5, the A1 region is a region where the wire diameter Φ 1 is less than 0.15 mm, and the spring is impossible or the spring elasticity is almost eliminated even when the wire is processed. The area B1 is an area in which wire wire diameters are 0.15 mm to 0.20 mm, and the area D1 is an area in which wire wire diameters are 0.40 mm to 0.50 mm. The C1 region is a region in which wire diameter is 0.20 mm to 0.40 mm, and the deviation of the operating temperature range is small near the operating temperature center value, and thus the optimum operating characteristics are exhibited. Therefore, when the wire diameter Φ 1 of the shape memory alloy spring 510 is 0.15 mm to 0.50 mm, it is possible to manufacture a repeatable fuse that can be operated in a small size. For example, it is possible to manufacture a repeatable fuse that can operate even when manufactured in a small size of about 1.5 mm in diameter and about 4 mm in length. In particular, when the wire diameter (Φ1) is 0.20mm to 0.40mm, it can be seen that a small repeating fuse having an optimal operating characteristic can be manufactured.

FIG. 6 is a diagram illustrating an operation characteristic of a repetitive fuse according to the number of wire turns T1 of the shape memory alloy spring.

In FIG. 6, the area A2 is an area where the number of wire turns T1 is less than 3.5, and thus the effective number of turns is not secured, and thus, an operation characteristic does not appear due to insufficient elasticity. The area B2 is an area of 3.5 to 4.0 wire turns, and the area D2 is an area of 6.5 to 7.0 wire turns, but the operating temperature range is somewhat different. The C2 region is a region in which the number of wire turns is 4.0 to 6.5, and the deviation of the operating temperature range is small near the operating temperature center value, and thus the optimum operating characteristic is exhibited. Therefore, when the wire turn number T1 of the shape memory alloy spring 510 is 3.5 to 7.0, it is possible to manufacture a repeatable fuse which can be operated in a small size, especially when the wire turn number T1 is 4.0 to 6.5, It can be seen that a repeatable fuse having an optimal operating characteristic can be manufactured.

FIG. 7 is a diagram showing the operating characteristics of the repetitive fuse according to the wire diameter Φ 2 of the bias spring.

As described above, the bias spring 520 is designed to obtain a corresponding tension with respect to the shape memory alloy spring 510 that is designed first.

In FIG. 7, the area A3 is an area where the wire diameter Φ 2 is less than 0.10 mm, and a spring operation is impossible or the spring elasticity is scarce even when the wire is processed. The area B3 is a wire wire diameter of 0.10mm to 0.15mm, and the area D3 is a wire wire diameter of 0.25mm to 0.30mm, but the operating temperature range is somewhat different. The C3 region is a region in which wire wire diameters are 0.15 mm to 0.25 mm, and the deviation of the operating temperature range is small near the operating temperature center value, and thus the optimum operating characteristics are exhibited. Therefore, when the wire diameter Φ 2 of the bias spring 520 is 0.10 mm to 0.30 mm, it is possible to manufacture a repeatable fuse that can be operated even when miniaturized, and particularly when the wire diameter Φ 2 is 0.15 mm to 0.25 mm. It can be seen that a repeatable fuse having an optimal operating characteristic can be manufactured.

FIG. 8 is a diagram illustrating an operating characteristic of the repetitive fuse according to the wire turn number T2 of the bias spring.

In FIG. 8, the A4 region is a region in which the wire turn number T2 is less than 4.0, and thus the effective turn number is not secured, and thus the operation characteristic does not appear due to lack of elasticity. The B4 region is an area having a wire turn number of 4.0 to 5.0, and the D4 region is an area having a wire turn number of 6.0 to 7.0, but the operating temperature range is somewhat different. The C4 region is a region in which the number of wire turns is 5.0 to 6.0, and the deviation of the operating temperature range is small near the operating temperature center value, and thus the optimum operating characteristics are exhibited. Therefore, when the number of wire turns T2 of the bias spring 510 is 4.0 to 7.0, it is possible to manufacture a repeatable fuse that can be operated even when downsizing, and particularly, when the number of turns of wires T2 is 5.0 to 6.0, optimally. It can be seen that a repeatable fuse having an operating characteristic of can be manufactured.

As described above with reference to the drawings illustrating a repeating fuse according to the present invention, the present invention is not limited by the embodiments and drawings disclosed herein, it is various within the technical scope of the present invention by those skilled in the art Of course, modifications can be made.

100: housing 120: locking jaw
200: first lead terminal 300: second lead terminal
400: spindle 410: support
510: shape memory alloy spring 520: bias spring
Φ1, Φ2: Wire diameter T1, T2: Number of wire turns
P1, P2: Wire Pitch H1, H2: Wire Height

Claims (12)

An iterative fuse comprising a shape memory alloy spring and a bias spring,
The shape memory alloy spring is formed in a coil shape whose wire diameter is 0.15 mm to 0.50 mm, and the number of wire turns is 3.5 to 7.0 repeated fuses.
The method according to claim 1,
The shape memory alloy spring has a wire diameter of 0.20 mm to 0.40 mm, and the number of wire turns is 4.0 to 6.5.
The method according to claim 1 or 2,
An outer diameter of the shape memory alloy spring is formed of a size of 7.0 to 8.5 times the wire diameter of the repeating fuse.
The method according to claim 3,
An average pitch of the shape memory alloy spring is 1.0mm to 1.5mm repetitive fuse.
The method according to claim 1,
The wire diameter of the bias spring is a repetitive fuse having a length of 60% to 65% of the shape memory alloy spring wire diameter.
The method according to claim 5,
The wire diameter of the bias spring is 0.10mm to 0.30mm, the number of wire turns is larger than the number of wire turns of the shape memory alloy spring, 4.0 to 7.5 repetitive fuse.
The method according to claim 5,
The bias spring has a wire diameter of 0.15 mm to 0.25 mm and the number of wire turns is 5.0 to 6.0.
The method according to claim 6 or 7,
The average pitch of the bias spring is a repeatable fuse of 1.0mm to 1.5mm.
The method according to any one of claims 1 or 2, 4 to 7,
The bias spring height is a repetitive fuse is formed in the size of 120% to 125% of the height of the shape memory alloy spring.
The method according to any one of claims 1 or 2, 4 to 7,
The shape memory alloy spring is a repetitive fuse is an alloy containing nickel (Ni) and titanium (Ti).
12. The method of claim 10,
The shape memory alloy spring comprises at least one of cobalt (Co), molybdenum (Mo), tungsten (W), chromium (Cr).
The method according to any one of claims 1 or 2, 4 to 7,
The bias spring is made of a SUS stainless steel material, the repetitive fuse manufactured by plating at least one of Ni, Cu, Ag, Au, Sn on the stainless steel

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