JP3403993B2 - Fuse with flux - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flux-attached fuse including a low melting point fusible alloy piece having a melting point of 80 [deg.] C. or less as a fuse element, and more particularly to an alloy type temperature fuse.

[0002]

2. Description of the Related Art An alloy type temperature fuse is constructed by connecting a low melting point fusible alloy piece between lead wires and applying a flux to the low melting point fusible alloy piece. Is surrounded by an insulating case, and the case is sealed with an adhesive such as an epoxy resin. The operating mechanism of this alloy type temperature fuse is that the low melting point fusible alloy piece is melted by the heat generated due to the abnormality of the equipment, and this molten metal is acted on by the lead wire while receiving the activating action of the already melted flux. Spherical separation is caused by the interfacial tension due to the wetting of the device, and when the separation distance reaches a predetermined arc interruption distance, the arc is interrupted and the power supply to the equipment is completely interrupted.

The above flux is expected to remove the oxide film of the low melting point fusible alloy pieces, prevent the oxidation of the molten alloy, and accelerate the wetting of the molten alloy. Conventionally, the flux of the low melting point soluble alloy piece is mainly composed of rosin, to which an activator such as organic chloride or bromide is added, if necessary.

[0004]

Recently, for diversification of equipment, alloy type temperature fuses that can be operated in a low temperature range of 80 ° C. or lower are required. However, in the temperature fuse in which the flux containing rosin as a main component is applied to the soluble alloy piece, the melting point of the soluble alloy piece is 8
When a low melting point alloy having a melting point of 0 ° C. or less is used, even if the low melting point fusible alloy piece is melted at the equipment protection temperature, the flux cannot be completely melted and no active effect is exerted on the molten metal. A quick break cannot be expected, and a satisfactory operation of the temperature fuse cannot be expected at all. Therefore, it is conceivable to use a resin having a melting point of 80 ° C. or lower as the flux instead of the flux containing rosin as a main component.

[0005]

However, with such a flux, (1) the mechanical strength of the flux coating film is lower than that of the rosin flux, and a low melting point fusible alloy piece is connected between the lead wires, When the insulating case is inserted after the low melting point soluble alloy piece is coated with the flux coating film, the flux coating film is likely to be cracked or peeled by the contact of the insulating case with the flux coating film. ) The film forming property of the flux is inferior to that using rosin as the main component of the flux, and it is difficult to form a flux coating film having a uniform thickness.

An object of the present invention is an advantage of an alloy type temperature fuse in which a low melting point fusible alloy piece having a melting point of 80 ° C. or less coated with flux is used as a fuse element, and the main component of the flux is rosin. It is an object of the present invention to provide an alloy type temperature fuse which can be quickly operated at a predetermined operating temperature while retaining the above.

[0007]

An alloy type temperature fuse as a temperature fuse with a flux according to the present invention is a flux melting low melting point alloy melting point having a melting point of 80 ° C. or less as a fuse element. In this fuse, lauroyl sarcosine is mixed with the flux, and the temperature fuse with the flux has an energization heating element, and the fuse is heated by the energization heat generation of the energization heating element.
A fuse with a heating element, which fuses the fuse element, is also included.

[Action] The melting point of lauroyl sarcosine is 5
At 2 ° C., when the low melting point soluble alloy piece is heated to its melting point, the rosin, which is the main component of the flux, is dissolved together with this lauroyl sarcosine, and the molten flux wets the lead wire of the molten alloy. Is promoted and the spheroidization is divided by the interfacial tension, and the molten alloy is divided. in this case,
The amino acid lauroyl sarcosine reacts with the reactive metal of the low melting point soluble alloy piece, particularly In, Zn, Cd, etc., to form a metal salt, and this metal salt accelerates the action of the flux. The division is done smoothly. In addition, even if rosin is used as the main component of the flux, this smooth division can be guaranteed, and since rosin can be used as the main component of the flux, even if exposed to arc during temperature fuse operation. As a result, decomposition and deterioration are well suppressed, and it is possible to effectively prevent the explosion of the case due to the generation of the internal pressure and the failure of the energization interruption due to the formation of carbide. Further, by using rosin as the main component of the flux, it is possible to increase the mechanical strength of the flux coating film, connect the low melting point fusible alloy pieces between the lead wires, and apply the flux to the low melting point fusible alloy pieces. After the coating of the film, when the insulating case is inserted, even if the insulating case comes into contact with the flux coating film, the flux coating film can be safely held without cracking or peeling. It is possible to form a flux coating film having a uniform thickness due to the excellent film forming property.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an example of an alloy type temperature fuse according to the present invention. In FIG.
1, 1 are a pair of lead wires (usually copper wires),
Both bare wire and covered wire can be used. 2 is lead wire 1, 1
It is a low melting point fusible alloy piece connected between and having a melting point of 80 ° C. or lower. 3 is a flux applied onto the low melting point fusible alloy piece 2 and contains lauroyl sarcosine. Reference numeral 4 denotes an insulating cylinder having heat resistance and good thermal conductivity which is inserted on the flux-coated low melting point fusible alloy piece, for example, a ceramic cylinder, a glass cylinder such as soda lime glass, and 5 each end of the insulating cylinder 4 and each lead. It is a room temperature curing adhesive that seals between the wire 1 and, for example, an epoxy resin can be used.

The main component of the above flux is rosin (natural rosin, polymerized rosin, hydrogenated rosin, malein modified rosin, formylated rosin, phenol modified rosin, glyco-acid modified rosin, disproportionated rosin, etc.). Can be used. In addition, an aliphatic amide, for example, stearic acid amide, can be added in order to adjust the melting characteristics of the flux. The amount of lauroyl sarcosine is usually 5-4.
The content of rosin is 0 to 30% by weight, the content of rosin is 30 to 95% by weight, and the content of aliphatic amide is usually 0 to 30% by weight.

The alloy-type temperature fuse according to the present invention uses, as a fuse element, a low melting point fusible alloy piece whose melting point is a temperature of 80 ° C. or lower at which heating and melting of rosin is substantially impossible. Lauroyl sarcosine reacts with the reactive metal of the low melting point soluble alloy piece, particularly In, Zn, and Cd to form a metal salt, and this metal salt is expected to accelerate the action of the flux. In with melting point soluble alloy pieces
It is preferably applied to alloy type temperature fuses containing Zn or Cd.

The alloy type temperature fuse according to the present invention includes, in addition to the above-mentioned cylindrical case type, a case type radial type,
Substrate type, resin mold radial type, tape type, etc. can also be used. FIG. 2 shows a case type radial type, in which a fuse element 2 is joined between the ends of the parallel lead conductors 1 and 1 by welding, a flux 3 is applied to the fuse element 2, and this flux is used. The coating fuse element is surrounded by an insulating case 4 having an opening at one end, for example, a ceramic case, and the opening of the insulating case 4 is sealed with a sealing material 5 such as epoxy resin.

FIG. 3 shows a substrate type, in which a pair of membrane electrodes 1 and 1 are formed on an insulating substrate 4, for example, a ceramic substrate by printing and baking a conductive paste (for example, silver paste), and each electrode 1 is formed. Connect the lead conductors 11 by welding,
A fuse element 2 is joined between the electrodes 1 and 1 by welding, a flux 3 is applied to the fuse element 2, and the flux-applied fuse element is sealed with a sealing material 4 such as an epoxy resin. .

FIG. 4 shows a resin mold radial type in which the fuse element 2 is joined between the tips of the parallel lead conductors 1, 1 by welding, and the flux 3 is applied to the fuse element 2. The flux coating fuse element is resin-molded 5 by resin liquid dipping.

FIG. 5 shows a tape type, in which a pair of strip lead conductors 1 and 1 are fixed to a resin base film 41 by an adhesive or fusion bonding, and the strip lead conductor tips are formed. The fuse element 2 is joined in between by welding, the flux 3 is applied to the fuse element 2, and the fuse applying fuse element is sealed by adhesion or fusion bonding of the peripheral portion of the resin cover film 42. There is.

Further, a fuse with an electric heating element, for example, an insulating substrate of a substrate type alloy fuse, is provided with a resistor (film resistance) so that the resistor is energized to generate heat when an abnormality occurs in the device. It can also be carried out in the form of a substrate type fuse with a resistor that melts the low melting point fusible alloy piece by the generated heat.

[0017]

[Embodiment 1] In the cylindrical case type of FIG. 1, the lead wire (copper wire) has a wire diameter of φ0.6 mm, the ceramic insulating cylinder has an inner diameter of φ1.5 mm, and an outer diameter of the same. φ2.
The length was 5 mm and the length was 9.0 mm, and an epoxy resin was used as the sealing resin. Wire diameter φ0.6m for low melting point alloy pieces
m, composition Bi 50% by weight, Pb 25% by weight, Sn12.
5% by weight Cd 12.5% by weight, melting point 72.0 ° C., and flux containing 30% by weight lauroyl sarcosine,
The composition of the balance natural rosin was used.

[Example 2] 10% by weight of lauroyl sarcosine, 20% by weight of stearic acid amide, and
Same as Example 1 except that the rest natural rosin composition was used.

Comparative Example 1 The same as Example 1 except that the composition of 30% by weight of stearic acid amide and the balance of natural rosin was used as the flux.

[Comparative Example 2] The composition of 20% by weight of acetamide and the balance of natural rosin was used as the flux,
Same as Example 1.

The operating temperature of each of the products of Examples and Comparative Examples (the number of each sample was 20) was measured (immersing in an oil bath and applying an electric current of 0.05 amperes to the oil at a rate of 1 ° C./minute). The operating temperature was measured by raising the temperature to the oil temperature at the time of current interruption in the temperature fuse, and the operating temperature was measured).

[0022]

[Table 1]                                 Table 1                                      Example 1 Example 2 Comparative Example 1 Comparative Example 2 Natural rosin (% by weight) Remainder Remainder Remainder Remainder Lauroyl sarcosine (% by weight) 30 10 − − Acetamide (% by weight) − − − 20 Stearic acid amide (% by weight) -20 30 20 Operating temperature (℃) 72.1 72.2 90.3 74.2

In Comparative Example 1, since the melting point of the flux is considerably higher than the melting point of the low melting point fusible alloy piece of 72.0 ° C., the operating temperature is higher than that of the low melting point fusible alloy piece. Yes, it cannot be used. In Examples 1 and 2, the melting point of the flux is 72.
It could be operated at a melting point of the melting point of the melting point of the melting point which is substantially lower than 0 ° C. Also in Comparative Example 2, the melting point of the flux was made substantially equal to the melting point of the flux of Example 2 by blending acetamide, but the operating temperature was higher than in Examples 2 and 1 and the operability was poor. The reason is that lauroyl sarcosine mixed in the flux of the example reacts with Cd of the low melting point soluble alloy piece during alloy melting to generate a metal salt, while an excellent flux action is exhibited. It is presumed that the acetamide compounded in the flux of Comparative Example 2 does not produce such an effect.

[0024]

According to the present invention, the melting point of the low melting point fusible alloy piece is 8
In the alloy type temperature fuse operating in a low temperature range of 0 ° C. or less, smooth operability can be guaranteed even though rosin having a melting point higher than the operating temperature is used as the main component of the flux. In addition, since rosin can be used as the main component of the flux, crack damage of the flux coating film during fuse manufacturing can be prevented, and the flux is decomposed by arc heat during fuse operation. The generation of internal pressure and the formation of carbide can be well prevented.

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of an alloy type temperature fuse according to the present invention.

FIG. 2 is a view showing another embodiment of the alloy type temperature fuse according to the present invention.

FIG. 3 is a view showing another embodiment of the alloy type temperature fuse according to the present invention.

FIG. 4 is a view showing another embodiment of the alloy type temperature fuse according to the present invention.

FIG. 5 is a view showing another embodiment of the alloy type temperature fuse according to the present invention.

[Explanation of symbols]

2 Low melting point alloy pieces 3 flux

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01H 37/76

Claims (2)

(57) [Claims] 1. A fuse with a flux, wherein a low melting point fusible alloy piece having a melting point of 80 ° C. or less coated with flux is used as a fuse element, and lauroyl sarcosine is mixed with the flux. 2. A fuse-attached fuse according to claim 1, wherein the fuse element has an electric heating element, and the fuse element is melted and blown by the electric heating of the electric heating element.