JPS5855612B2 - Overheat protector for electrical appliances - Google Patents

Description

[Detailed description of the invention] The present invention relates to an overheat protector for electrical appliances.

As a means for preventing overheating in transformers, electric wires, electric motors, electromagnets, stabilizers, etc., there is an overheat protector proposed by the present inventor, which is disclosed in Utility Model Registration No. 1136581.

This overheating protector consists of two lead-out wires in which a solder alloy is spread and joined together, and the tip of the lead-out wire containing the solder alloy is wrapped in a flat insulating coating. Compared to a temperature fuse that combines a cylindrical glass case, wax, and coil springs, the structure and handling are simpler, and the tension of the coil spring can be used to cut fusible alloys or melt wax. It does not rely on the mechanical action of expanding the coil spring and pulling the contacts apart, but rather on the vibration action of the solder alloy due to the temperature and current of the coil and alternating current magnetism, making operation more accurate and reliable than with a temperature fuse.

However, since this overheating preventer uses a method that obtains magnetism, which is one of the operating factors, from the outside, the applicable devices are limited to wire wheels, and in order to ensure flatness, the upper side of the semi-warm alloy is used. Since the lower side is directly sandwiched between adhesive tapes, the vibration effect of the solder alloy is likely to be hindered when the magnetism generated by the device is weak or the direction of the magnetism is random. There was a problem in that the scattering space for the solder alloy was small, so there was a risk of re-welding.

The present invention aims to further improve the overheat protector,
Its basic purpose is that it can be applied not only to coils but to all AC electrical appliances, and in each case it can generate strong vibrations at a set temperature to interrupt the circuit very accurately and reliably, and is an electrical insulator. The purpose is also to provide a good overheating protector.

Another object of the present invention is to provide an overheat protector that can reliably prevent overheating not only for AC electric appliances but also for DC electric appliances.

In order to achieve this object, the present invention not only connects a heat-sensitive element made of an easily meltable alloy between a plurality of lead wires, but also connects the tip of the lead wire containing the heat-sensitive element with a magnet. A hole is formed in the magnet piece at a position corresponding to the heat-sensitive element to accommodate the heat-sensitive element, and a strong magnetic force is applied to the heat-sensitive element by the magnetic circuit possessed by the magnet piece itself. The fuse is designed to vibrate greatly in the free space within the opening to effect the melting, and the solder alloy grains after the melting are allowed to naturally fall and collect within the opening.

Furthermore, the present invention configures the magnetic poles of the magnet pieces into a plurality of sets of magnetic poles in which adjacent pieces have opposite polarities, thereby not only vibrating the heat-sensitive element but also vibrating the heat-sensitive element along its entire length. By applying tensile forces in opposite directions, the heat-sensitive element can be fused extremely reliably at a set temperature.

Embodiments of the overheat protector for electrical appliances of the present invention will be described below with reference to the accompanying drawings. Figures 1 to 8 show basic embodiments of the present invention, in which a magnet piece 1 has a plurality of strips. The tips of the lead wires 2 are attached approximately parallel to each other, and a heat-sensitive element 3 made of a solder alloy or an easily melted alloy equivalent thereto is strung between the ends of both lead wires 2a and 2b in a bridge shape, and the heat-sensitive element 3 is connected to the lead wires 2a and 2b. The contact points with the wires 2a and 2b are joined, and the magnet piece 1 is further formed with an opening 4 in which the heat-sensitive element 3 can be accommodated at a position corresponding to the heat-sensitive element 3, and the magnet piece 1 includes the heat-sensitive element 3. An insulating coating 5 is provided around the piece 1.

Next, FIGS. 9 and 10 show an embodiment in which three or more of the plurality of lead wires 2 are used to create an overheat protector with a spare. 3 lead lines 2a
, 2b, 2c, and the lead wires 2a, 2b, 2
A heat-sensitive element 3 is placed between the tips of the heat-sensitive elements 3, and the magnet pieces 1 are provided with independent holes or a series of holes 4 in the magnet pieces 1 at positions corresponding to the heat-sensitive elements 3.

On the other hand, the embodiment of FIG. 10 is
Use two sets of lead wires 2a and 2b, and connect them to the magnet piece 1.
Apertures 4 are mounted in parallel to each other, and at positions corresponding to the heat-sensitive elements 3, 3 of each set, are provided with apertures 4 that are independent of each other or connected as shown in the figure.
was formed.

Here, the magnet piece 1 in FIGS. 1 to 10 is a permanent magnet made of a metal magnetic material such as an artificially magnetized iron piece magnet, a ceramic (barium ferrite) magnet, an alnico magnet or a soft barium ferrite magnet, or a permanent magnet made of a metal magnetic material such as a rubber or synthetic magnet. A flexible composite permanent magnet in which a magnetic material such as barium ferrite is bonded to a plastic insulating material barb such as resin may be used.

In particular, when the latter magnet piece 1 is used, it has good compatibility with the surface of the electric appliance to be prevented from overheating, and even if there is an uneven surface, it can be attached in close contact with the surface. The heat transfer effect can be made very good.

At the same time, due to its moderate flexibility, it has the advantage of not damaging the mounting surface of electrical appliances.

Next, the shape of the opening 4 in each embodiment is arbitrary, and the width of the short side of the housing is preferably at least twice the diameter of the heat-sensitive element 3. The side width may be equal to or greater than the length of the heat-sensitive element 3 (the size that crosses the leader line 2) as shown in Figure 11A, or the width of the side may be equal to or greater than the length of the heat-sensitive element 3 as shown in Figure 11A. It may be shorter than that.

Therefore, the lead wire 2 and the magnet piece 1 of the heat-sensitive element 3 in each of the embodiments shown in FIGS. 1 and 3 and FIGS. 9 and 10 are
There is also no particular limitation on the mounting structure for.

That is, as shown in FIGS. 1 and 2, the lead wire 2 may be attached to the upper surface of the magnet piece 1, or as shown in FIGS. A notch or hole 11 is provided along the direction intermediate part, and this notch or hole 1
The lead wire 2 may be inserted into the magnet piece 1 through the magnet piece 1.

Furthermore, instead of this structure, as shown in Figs. 7 and 8, a thin 2
Using two magnet pieces 1a and 1b, these magnet pieces 1a.

The lead wire 2 may be sandwiched between the wires 1b.

In the latter two cases, it is convenient because the heat-sensitive element 3 is located in the middle of the opening 4 as shown in the figure.

In the case of FIGS. 1 and 2, a concave groove is formed in the magnet piece 1 and the lead wire 2 is inserted into the groove, or a hole 4 is formed at the tip of the lead wire 2 by rolling pressure with a roller, etc. Just push it in properly.

Finally, the insulation coating 5 may be a synthetic resin film formed by a molding method as shown in FIGS. 1 and 2, or may be a synthetic resin film formed with an adhesive layer on the surface as shown in FIGS. It may be made of insulating paper, or it may be made of a hishitube as shown in Figs. 7 and 8. Furthermore, the above-mentioned insulating coverings may be combined, for example, insulating paper may be pasted as a lower layer. A synthetic resin film may be coated over the shiso, or the shiso tube may be wrapped.

The above is the basic configuration of the present invention, but the present invention further provides that the magnetic poles of the magnet piece 1 are arranged not simply in two poles as shown in FIG. Another feature is that a plurality of sets of magnetic poles are provided in which one magnetic pole is successively positioned next to another magnetic pole.

In either case, the magnet piece 1 may be magnetized before the lead wire 2 and the heat-sensitive element 3 are attached, or it may be magnetized after the lead wire 2 and the like are assembled.

Next, to explain the function of the desuperheater according to the present invention, the desuperheater A of the present invention is used for electric appliance B
It is attached to the appliance and is electrically connected in series with the appliance using the lead wire 2.

In other words, if the target electric appliance B is a wire ring, the space between the layers of the primary winding 8 and the secondary winding 9, or between the windings of the primary winding 8 or the secondary winding 90, etc. Attach it to any position.

In addition, if the applicable electric appliance B is, for example, an electric stove, an electric hot water bath, an electric foot warmer, or other heating appliances, an electric oven, a cooking appliance such as a microwave oven, or a lighting appliance such as a fluorescent lamp, such appliances For example, the position where the temperature is the highest towards
It is installed or inserted into the gap or surface of 2.

In these cases, since the entire body is surrounded by the insulating coating 5 and has a relatively flat shape, the mounting operation is simple and a sufficient heat transfer area can be provided.

However, in the above state, the magnetism from the magnet piece 1 is acting in the direction perpendicular to the length direction of the heat-sensitive element 3, but the electric appliance B is not operated below the rated maximum temperature rise. During this time, the heat-sensitive element 3 does not reach the melting temperature and is in a solid state, so no vibration occurs.

However, after that, some kind of failure such as an input/output abnormality occurs and an excessive current flows through electric appliance B. As a result, the temperature of electric appliance B rises and reaches the set temperature of the heat-sensitive element 3, which melts the heat-sensitive element 3. You will be able to move freely.

In this state, the heat-sensitive element 3 vibrates due to the current flowing through the electric appliance B and the magnetism, and the center part in the length direction gradually becomes thinner due to surface tension.Finally, the moment when this thinner center part separates into two parts. It is completely cut off by the spark, but in this case, the magnetism that is the vibration factor of the heat-sensitive element 3 originates from the large-volume magnet piece 1 that is the base on which the heat-sensitive element is attached, and the magnet piece 1 itself is as shown in FIG. Since a magnetic circuit is formed in the heat-sensitive element 3, magnetic force acts strongly and efficiently on the heat-sensitive element 3.

Moreover, at this time, the heat-sensitive element 3 is located within the aperture 4, and there is a sufficiently large free space around the heat-sensitive element 3, so the strong magnetic force causes the heat-sensitive element 3 to vibrate strongly as shown in FIG. Therefore, in any AC-powered electrical appliance, and even in cases where the magnetic leakage direction and strength vary, such as in a ring core, the circuit can be operated very accurately and reliably at the set temperature. It is possible to cut off the noise and reduce the variation in one operation.

Moreover, in the present invention, when the magnetic poles of the magnet piece 1 are arranged in a multipolar arrangement as shown in FIG. Since a pulling action is applied to each part in the direction perpendicular to the length direction and in the opposite direction, it is possible to cut the heat-sensitive element 3 more reliably and accurately by the synergistic effect of the pulling or tearing movements in opposite directions. Therefore, it is possible to accurately prevent overheating in all electric appliances regardless of whether they use alternating current or direct current.

Further, the heat-sensitive element 3 is cut as described above, but at this time, since there is an opening 4 around the heat-sensitive element 3, the scattered heat-sensitive element particles 3' fall into the opening 4 due to gravity as shown in FIG. It naturally aggregates and solidifies.

Therefore, there is no phenomenon in which the scattered heat-sensitive element particles 3' are again welded to the lead wire 2 in a line shape, and the degree of electrical insulation can be extremely improved.

In the case of the embodiments shown in FIGS. 9 and 10, any two of the three or more lead wires 2a, 2b are connected in series with the electric appliance B, and the remaining one or The two lead lines 2c, 2a, and 2b are left free without being connected.

In this way, only the heat-sensitive elements 3 of the connected leader lines 2a and 2b are cut in the above-described behavior, and the other heat-sensitive elements 3
Since no current flows in the case of , 1 remains, which is passed across the lead wire.

After the circuit is opened, when using the repaired appliance B,
The lead wires 2b, 2c or 2a, 2b connected to the remaining heat-sensitive element 3 as described above are connected again in series with the electric appliance B, so that the heat-sensitive element 3 will be activated the next time it overheats. , it is possible to effectively prevent overheating multiple times.

As described above, according to the first aspect of the present invention, the heat-sensitive element 3 is placed in the free space of the opening 4, and the electric current flowing through the lead wires 2, 2 and the heat transfer from the electric appliance B are large and the heat-sensitive element 3 has a large volume. Since it is efficiently vibrated by strong magnetism from the magnet piece 1 having a magnetic circuit, it is possible to prevent overheating of electrical appliances not only limited to coils but also used with all commercial AC power sources with high accuracy and reliability.

Further, since the opening 4 simultaneously functions as a housing portion for the heat-sensitive element 3 after being fused, the overheating preventer can have reliable electrical insulation.

Furthermore, the number of parts as a whole is small, and the magnet piece 1 is the heat-sensitive element 3.
Since the attachment of the lead wire 2 also functions as a board, the overheat protector can be manufactured easily and with little variation.

Furthermore, according to the second aspect of the present invention, the magnet piece 1 is provided with a plurality of sets of polar magnets having different adjacent poles, so that in addition to the behavior according to the first aspect described above, the heat-sensitive element 3 is caused to have complicated tearing. The action can therefore be made even more reliable and precise.

Therefore, the applicable electrical appliances are not limited to those using an AC power source, but can also be applied to electrical appliances using a DC power source, and high accuracy and reliability in overheating prevention can be ensured in all such electrical appliances.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway plan view showing one embodiment of the overheating preventer according to the present invention, Fig. 2 is a sectional view taken along line ■-■ in Fig. 1, and Fig. 3 is another embodiment of the present invention. Fig. 4 is a rear view of Fig. 3, Fig. 5 is a sectional view taken along line V-v in Fig. 3, and Fig. 6 is a cross-sectional view taken along line Vl-Vl in Fig. 3. FIG. 7 is a longitudinal sectional rear view showing another embodiment of the present invention, and FIG.
The figures are also a cross-sectional view taken along the line ■-■ in FIG. 7, FIG. 9 is a partially cutaway plan view showing another embodiment of the present invention, and FIG. The top view, FIG.
Figure 12A, opening is a sectional view illustrating the usage state of the overheat preventer of the present invention, Figure 13 is an explanatory diagram showing the state of magnetic flux distribution of the magnet piece in the present invention, Figure 14A, opening is a cross-sectional view illustrating the usage state of the overheating preventer of the present invention. FIG. 15 is a cross-sectional view showing the operating state of the heat-sensitive element according to the present invention, and FIG. 16 is a cross-sectional view showing the state after fusing. In the drawings, 1... Magnet piece, 2... Plural lead wires, 3... Heat sensitive element, 4... Open hole, 5... Insulating coating, respectively.

Claims (1)

[Scope of Claims] 1. The tips of a plurality of lead wires 2, which are connected across a heat-sensitive element 3 made of an easily meltable alloy, are attached to a magnet piece 1, and the magnet piece 1 is provided with a position corresponding to the heat-sensitive element 3. An overheat protector for an electric appliance, characterized in that an opening 4 is formed in the magnet piece 1 and an insulating coating 5 is provided around the magnet piece 1. 2. The overheat preventer for an electrical appliance according to claim 1, wherein there are two lead wires 2. 3. The overheat preventer for an electrical appliance according to claim 1, wherein the number of lead wires 2 is three or more. 4. The overheat preventer for an electric appliance according to claim 1, wherein the magnet piece 1 is a permanent magnet made of magnetized metal magnetic material. 5. Claim 1, wherein the magnet piece 1 is a flexible soft permanent magnet made of a composite of a soft electric insulator and a magnetic material.
Overheat protectors for electrical appliances listed in Section 1. 6. The overheat protector for an electrical appliance according to claim 1, wherein the lead wire 2 is mounted on the upper surface of the magnet piece 1. 7. The overheat protector for an electric appliance according to claim 1, wherein the attachment position of the lead wire 2 is at the middle part of the magnet piece 1 in the thickness direction. 8. The overheat protector for an electrical appliance according to claim 1, wherein the opening 4 has a length equal to or greater than the length of the heat-sensitive element 3. 9. The overheat protector for an electrical appliance according to claim 1, wherein the opening 4 has a size shorter than the entire length of the heat-sensitive element 3. 10 The tips of a plurality of lead wires 2, which are connected across heat-sensitive elements 3 made of an easily meltable alloy, are attached to a magnet piece 1, and holes 4 are formed in the magnet piece 1 at positions corresponding to the heat-sensitive elements 3. An overheating preventer for an electrical appliance, characterized in that the magnet piece 1 is provided with a plurality of sets of magnetic poles in which adjacent comrades have different poles, and an insulating coating 5 is provided in place of one of the magnet pieces 1. 11 Claim 10 in which there are two lead lines 2
Overheat protectors for electrical appliances listed in Section 1. 12. The overheat preventer for an electrical appliance according to claim 10, wherein the number of lead wires 2 is three or more. 13. The overheat preventer for an electrical appliance according to claim 10, wherein the magnet piece 1 is a permanent magnet made of magnetized metal magnetic material. 14. The overheat protector for an electrical appliance according to claim 10, wherein the magnet piece 1 is a flexible soft permanent magnet made of a composite of a soft electrical insulator and a magnetic material. 15. The overheat protector for an electrical appliance according to claim 10, wherein the lead wire 2 is attached to the upper surface of the magnet piece 1. 16. The overheat preventer for an electrical appliance according to claim 10, wherein the attachment position of the lead wire 2 is a thicknesswise intermediate portion of the magnet piece 1. 17. The overheat preventer for an electrical appliance according to claim 10, wherein the opening 4 has a length equal to or greater than the length of the heat-sensitive element 3. 18. The overheat preventer for an electrical appliance according to claim 10, wherein the opening 4 has a size shorter than the entire length of the heat-sensitive element 3.