JPH08255538A - Plane-like thermal fuse - Google Patents

Abstract

PURPOSE: To provide a plane-like thermal fuse in which the deterioration of an insulation film by flux can be excluded, and further, a quick operation can be assured, in the plane-like thermal fuse with a thermal insulation plate which touches a jetting burning gas from the opening of the shell plate portion of a burning appliance and operates so as to stop burning to prevent the abnormal overheating of the burning appliance in advance. CONSTITUTION: Recessed row 13 of a predetermined pattern is provided in one side face of a metal plate 1 having an insulation film at least on one side face thereof. A flux-including low melting point fusible metal wire 6 which is formed by having flux 5 in the hollow hole of a hollow low melting point fusible metal wire is contained in the recessed row 13, and sealing resin 8 is molded in the recessed row 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet temperature fuse used for preventing overheating of combustion equipment such as an instantaneous water heater.

[0002]

2. Description of the Related Art In a combustion apparatus such as an instantaneous water heater, rapid fatigue and frequent repetition of heating and cooling cause early thermal fatigue of the body of the combustion chamber. Corrosion of the body plate portion due to corrosive components also overlaps, and there is a fear that combustion holes in the body plate portion will be ejected to the outside, which may cause a secondary disaster.

In order to eliminate such a risk, a surface temperature fuse with a heat shield plate is provided between the rear surface of the combustion chamber body plate portion and the outer casing, and the surface temperature fuse is attached to the wall surface of the jet combustion gas. The contact with the heat shield is prevented by the heat shield, and the surface temperature fuse is activated by the contact of the jetted combustion gas with the heat shield, and the gas supply solenoid valve is closed by the microcomputer control to stop the gas combustion. Proposed.

As the surface temperature fuse with the heat shield plate,
As shown in (a) and (b) of FIG. 8 [a cross-sectional view of (a) of FIG. 8], a meandering groove 13 ′ is formed on one side of a metal plate 1 ′ having an insulating film 11 ′ on one side. Press molding, this groove 1
It has been proposed that a low melting point fusible metal wire 6'is housed in 3 ', and an insulating coating layer 8'is provided on one surface of a metal plate (Japanese Utility Model Laid-Open No. 5-27558).

Further, as shown in FIG. 9, the insulating film 1 is formed on one surface.
Electrode groups 2 ', ... Are provided on both ends of one side of a metal plate 1'provided with 1'.
, And the low melting point fusible metal wires 6 ', ... are connected across both electrode groups, and the flux 5', ... is applied to the low melting point fusible metal wires. It is proposed that an insulating layer 8'is provided so as to cover the metal wire and the electrode 2 '(JP-A-5-12972).

[0006]

In the above-mentioned sheet temperature fuse with a heat shield plate, when the combustion gas ejected from the opening of the body plate portion comes into contact with the metal plate, it is located at the shortest distance from the contact point. The low melting point fusible metal wire part is melted and actuated. In this case, the shorter the shortest distance is, the quicker the actuation can be performed. Therefore, the low melting point fusible metal wire is arranged at the shortest distance possible. Is required.

In the above-mentioned sheet temperature fuse with a heat shield plate, FIG.
In the sheet temperature fuse with a heat shield plate shown in (a) and (b), the low melting point soluble metal wire 6 ′ is accommodated in the groove 13 ′ of the press-molded metal plate 1 ′, which has a low melting point. The fusible metal wires 6 ', ... Can be easily arranged at predetermined short intervals by eliminating mutual contact. However, by leaving a gap between the groove 13 ′ and the low melting point fusible metal wire 6 ′ and allowing the molten metal to flow through the gap when the low melting point fusible metal wire 6 ′ is melted, a low melting point is possible. The molten metal wire 6'is melted and cut, and an oxide film is formed on the low melting point soluble metal wire 6'because of oxygen in the voids. Due to the insolubility of the oxide film, the low melting point soluble metal wire 6 ' Fusing becomes difficult and there is a problem in fusing operation characteristics. In addition, in the curved portion 131 ′ of the meandering groove 13 ′, there is a problem that a complicated processing strain is generated during pressing, the metal plate 1 ′ is anti-curved, and a crack is easily generated in the curved portion 131 ′.

On the other hand, a surface temperature fuse with a heat shield plate shown in FIG.
, The low melting point fusible metal wire 6'and the flux 5 '
Since the coating is applied, the above-mentioned oxidation can be prevented and good fusing characteristics can be guaranteed. However, it is not easy to position the low melting point fusible metal wires 6 ', ... When arranging the low melting point fusible metal wires 6', ... at predetermined intervals. Further, since the flux is in contact with the insulating film of the metal plate, there is a concern that the active component (organic acid, organic hydrochloride, hydrobromide, etc.) in the flux may cause a failure due to deterioration of the insulating film. Further, since the electrode 2'is fixed to the metal plate 1'in a considerably large area, most of the heat received by the metal plate 1'during normal combustion of the combustion equipment is from the electrode 2 ', the low melting point soluble metal wire. Although it is easily transmitted to the electrode contact portion 6 ', and there is no abnormality in the device, this low melting point soluble metal wire portion is likely to be fused early and malfunctions.

An object of the present invention is to provide a surface temperature with a heat shield for preventing abnormal overheating of the combustion equipment by operating in contact with the combustion gas injected from the body plate opening of the combustion equipment to stop combustion and prevent abnormal overheating of the combustion equipment. In the fuse, the surface temperature fuse which can eliminate the deterioration of the insulating film due to the flux and can guarantee the quick operation.
Is to provide Further, an object of the present invention is to operate a sheet gas of a combustion equipment in contact with a combustion gas injected from a body plate opening of the combustion equipment to stop combustion and prevent abnormal overheating of the combustion equipment. In addition, the deterioration of the insulating film due to the flux can be eliminated, and the recessed line for accommodating the low melting point fusible metal wire can be easily press-molded without the occurrence of cracks, etc. Provide a planar temperature fuse that can be easily positioned and arranged, guarantees quick operation, and can reliably eliminate malfunction of temperature fuse during normal operation of protected combustion equipment. To do.

[0010]

A flat temperature fuse according to the invention of claim 1 has a hollow low melting point in which a metal plate having an insulating film on at least one surface thereof is provided with a groove having a predetermined pattern. A flux-containing low-melting point soluble metal wire having a flux in the hollow hole of the soluble metal wire is housed in the recessed line, and a sealing resin is molded in the recessed line. is there.

In the sheet temperature fuse according to the invention of claim 2, a plurality of recessed lines are provided on one side of a metal plate having an insulating film on at least one side, and inside the hollow hole of the hollow low melting point fusible metal wire. The flux-containing low-melting point soluble metal wire having a flux is housed in each of the above-mentioned recesses, and the flux-containing low-melting point soluble metal wire group is connected in series by a connector and sealed in each of the above-mentioned recesses. A first insulating preform having a bridge conductor for connecting the low melting point fusible metal wires in series on one side according to claim 3, which is characterized in that the stop resin is molded. -A laminate in which one surface of the plate member is in contact with the other surface of the second insulating plate member is fixed to one surface of the metal plate on the other surface of the first insulating plate member to provide a connector, and each low melting point is provided. The end of the fusible metal wire is the first insulation plate
It can be electrically conducted by being soldered or welded to the bridge conductor of the belt member.

[0012]

[Operation] Since the low melting point fusible metal wire containing flux is housed in the recessed strip, the metal wire can be easily positioned,
The low melting point soluble metal wire can be easily arranged at predetermined intervals. Further, since the low melting point soluble metal wire containing flux is used, the molten flux enhances the interfacial energy on the surface of the molten metal with respect to the molten low melting point soluble metal wire and promotes the spheroidization of the molten metal. It can guarantee quick fusing operability.
Furthermore, the flux is put in the hollow hole of the low melting point fusible metal wire, and the non-contact between the insulating film of the metal plate and the flux is guaranteed at all times, so failure due to insulation deterioration of the insulating film is eliminated. it can.

Particularly, in the sheet temperature fuse according to the second and third aspects, since the arranged low melting point metal wires are connected in series by the connector, the low melting point metal wires are accommodated. Since the groove is linear and does not require a bent portion, it is possible to eliminate the occurrence of inversion of the metal plate or cracking which is unavoidable when there is a bent groove when press-forming the groove. Also,
It is not necessary to fix the electrode to the metal plate, and it is possible to eliminate a malfunction that tends to occur when most of the heat received by the metal plate during normal combustion of the combustion equipment is transferred from the electrode to the electrode contact portion of the low melting point fusible metal wire. .

[0014]

Embodiments of the present invention will be described below with reference to the drawings. 1A is a plan view showing a metal plate used in the embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along the line of FIG. 1A, showing good heat conduction on at least one surface. A plurality of concave stripes 13 sandwiched between a pair of convex stripes 12, 12 are formed in parallel on one surface side of the metal plate 1 having a conductive insulating thin film 11. Reference numerals 14 and 14 denote flat portions on both ends of one side of the metal plate, and 15 ... Bind holes.
As the metal plate 1, a press-formed aluminum plate having an oxide film formed by alumite treatment can be used. Further, as the metal plate 1, as shown in FIG. 2, it is possible to use one in which a plurality of recessed ridges 13 sandwiched between the ridges 12 having a relatively wide width are formed in parallel.

3A and 3B are plan views showing a connector member used in the embodiment of the present invention, and FIG. 3C is a top view of FIG. 3B. A cross-sectional view, FIG. 3D is a cross-sectional view taken along the line II in FIG. In FIG. 3A, reference numerals 31 and 32 denote first insulating plate members, and a bridge conductor 31 for connecting each low melting point fusible metal wire in series to one surface of the insulating plate.
, ..., 321, ... are fixed. 322,322
Is a lead conductor. In FIG. 3B, 21,
Reference numeral 22 denotes a second insulating plate member, which is a cutout portion 211,
, 221, ..., 222, 222 are provided. When the other surface of the second insulating plate member 21 (22) is placed on one surface of the first insulating plate member 31 (32), the cutouts 211 of the second insulating plate member 21 (22) are formed. (22
1), 222 to each end 311a (32) of the bridge conductor 311 (321) of the first insulating plate member 31 (32).
1a), or each end 322a of the lead conductor 322 is exposed. For these first insulating plate member and second insulating plate member, a conductive coating material such as, for example,
It is possible to use those obtained by screen-printing a silver paste and baking it, or those obtained by etching the metal foil of the metal foil laminated insulating plate with a predetermined pattern.

In FIGS. 3A to 3D,
Reference numerals b, ... Are holes for laminating and bonding both members 21, 31 (22, 32). For the bonding through these holes, (a) of FIG. 4 (side view) and FIG. (B) As shown in (a cross-sectional view of FIG. 4 (a)), the rivet 4 in which the core 42 is press-fitted into the rivet main body 41 (made of plastic or metal) having a crack and capable of expanding and contracting can be used.

5 (a) to 5 (g) are claims.
FIG. 6A is a plan view showing a planar temperature fuse according to an embodiment of the invention of FIG. 5 in a manufacturing process. FIG. 5E shows a cross-sectional view taken along the line HO in FIG. 5) and FIG. 5 (g) respectively show a cross section and a cross section of FIG. 5 (d).

At the manufacturing stage shown in FIG.
One side of the metal plate 1 is directed to the upper side, and the first insulating plates 31 and 32 of the connector are placed on the flat portions at both ends with the conductor (bridge conductors 311 and 321 and lead conductor 322) fixed surface facing upward. Are arranged.

At the manufacturing stage shown in FIG. 5B,
Each first insulating plate 31 (32) in FIG.
The second insulating plates 21 (22) and the first insulating plates 31 are stacked on top of each other.
The laminated body with (32) is fixed by the rivet 4 of FIG. 4 through the binding holes b, b to provide the connectors-c, c. At this stage, the second insulating plate 21 (2
2) each notch portion 211, 221, 222 to each bridge conductor 311 (32) of the first insulating plate 31 (32).
Each end 311a (321a) of 1) or each end 322a of the lead conductor 322 is exposed.

At the manufacturing stage shown in FIG. 5C,
As shown in (e) of FIG. 5, the flux 5 (having a lower melting point than the low melting point fusible metal wire 6 described later) is placed in the recess 13 of the metal plate 1.
Flux-containing low-melting point metal wire 6 having hollow inside
(Flux 5 has a lower melting point than low melting point fusible metal wire 6), and both ends of each low melting point fusible metal wire 6 are connector-c.
First insulating plate 31 (32) bridge conductor 31
1 (321) is connected to each end 311a (321a) by soldering or welding, and each lead conductor 322 is connected.
To each end 322a of each lead wire 7 by soldering or welding (in the illustrated embodiment, notches 222 and 222 are provided for each of the lead wires 7 and 7). However, these notches 222 and 222 can be integrated into one). Thus, by connecting these, the low melting point fusible metal wire 6 containing flux, ...
The power lines 7 and 7 are electrically connected in series.

At the manufacturing stage shown in FIG. 5D,
In contrast to the semi-finished product shown in FIG.
As shown in (f) and (g), the resin sealing material 8, for example, an epoxy resin adhesive is molded to seal the flux-containing low melting point soluble metal wire 6 and the first insulation. Each end 311 of the bridge conductor of the plate 31 (32)
a, 321a and each end 322a of the lead conductor are insulated by the same resin coating 81. The epoxy resin adhesive is preferably filled with an inorganic filler to enhance thermal conductivity (for example, glass fiber, asbestos, talc, silica sand, alumina, calcium carbonate, clay, carbon, metal oxide, Any one or more of inorganic compounds of metals).

The above description has been given for the embodiments of the inventions of claims 2 and 3. In the embodiment of the second aspect of the invention, as shown in FIG. 6, an insulating coated conductive wire (c ₁ is a conductive wire and c ₂ is an insulating coating) can be used for the connector-c. According to the invention of claim 1, a meandering groove is provided on one surface of a metal plate having an insulating film on at least one surface, and a flux-containing low melting point metal having a flux is contained in the hollow hole of the hollow low melting point fusible metal wire. It can also be carried out by placing the molten metal wire in the groove and molding the groove with a sealing resin.

FIG. 7 shows a usage state of the sheet temperature fuse according to the present invention. In FIG. 7, 91 is a gas bar
Reference numeral 92 denotes a fan, and 93 denotes a body plate portion provided on the gas burner 91, and the interior of the body plate portion 93 is a combustion chamber.
Reference numeral 94 is a heat exchanger attached to the upper part of the combustion chamber, and 95 is a combustion gas outflow pipe. When the combustion gas passes through the heat exchanger 94, water flows in the heat exchanger while being heated. . Reference numeral 961 denotes a water supply pipe to the heat exchanger 94, and 962 denotes a hot water supply pipe from the heat exchanger 94, which is wound around the body plate portion 93. An outer casing 97 has a slit 971 for sucking air in front of the combustion chamber.
A is a sheet-like temperature fuse according to the present invention, and it is preferable that the surface of the metal plate 1 opposite to the surface on which the low melting point fusible metal wire is fixed is directed to the body plate portion 93 side.

In FIG. 7, the body plate portion 93 is opened, and combustion gas is ejected from the opening. When the ejected combustion gas comes into contact with the metal plate 1 having the sheet temperature fuse A, the contact position is changed. Heat is transferred as the center, and the sheet temperature fuse A
The low melting point fusible metal wire is melted from the portion closest to the combustion gas contact position, and the gas supply solenoid valve of the gas burner is closed by the division of the molten metal to stop the combustion.

Thus, the time from the contact of the jetted combustion gas with the heat shield plate to the melting of the low melting point fusible metal wire is the distance from the combustion gas contact position to the closest low melting point fusible metal wire portion. L, the low melting point fusible metal wire portion largely depends on the time t, etc. between the melting and the cutting, but in the planar temperature fuse according to the present invention, the space between the recesses 13 and 13 is large. The interval between the low melting point fusible metal wires 6 can be sufficiently shortened by reducing the distance between the two, and the contact position of the jetted gas with the heat shield plate, and thus the opening position in the body plate portion, can be determined. Nevertheless, the above distance L can be sufficiently shortened, and when the low melting point fusible metal wire is melted, the interfacial energy of the molten metal in contact with the flux which has already been melted becomes large and the molten metal is spheroidized. The above-mentioned t can be shortened, and quick operability can be guaranteed. That.

In FIG. 7, in order to reduce the thickness of the combustion equipment, it is required to make the distance between the body plate 93 and the outer casing 97 as small as possible. In this case, even during normal combustion, The metal plate 1 of the sheet temperature fuse A is heated to a considerably high temperature, and in the flux-containing low melting point soluble metal wire, the flux may melt even if the low melting point soluble metal wire does not melt. In this case, in the conventional sheet temperature fuse shown in FIG. 8, the insulating film 11 'of the metal plate 1'is insulation-degraded due to the activation of the molten flux, which may cause a failure in the operating system. However, in the sheet temperature fuse according to the present invention, since the flux is contained in the low melting point fusible metal wire, there is no such risk.
Further, in the conventional sheet temperature fuse shown in FIG. 9,
A large amount of heat is received from the metal plate 1'to the electrode 2'which is directly fixed to the metal plate 1 ', and there is a fear of malfunction due to fusing of the low melting point fusible metal wire portion which is close to the electrode 2'. In the planar temperature fuse according to the present invention, the connector-c is used for connecting the parallel low melting point soluble metal wires 6, ... In series, and the low melting point soluble metal wire from the metal plate 1 to the connector-c is used. The heat flow to the end connecting conductor ends (311a, 321a) is applied to the contact interface between the connector-c and the metal plate 1, the connector-c.
Since it can be well prevented by the insulating plate or the like, the malfunction due to the melting of the low melting point fusible metal wire portion in the vicinity of the terminal electrode can be sufficiently eliminated.

By arranging the low-melting point fusible metal wire in the horizontal direction, the combustion gas rising up can always have a low-melting point regardless of the position of the hole in the body of the combustion chamber. It is possible to cross the molten metal wire, which is advantageous because the operation reliability can be improved.

[0028]

The surface temperature fuse according to the present invention is constructed as described above, uses the flux-containing low melting point fusible metal wire, and normally operates the equipment before operating the temperature fuse. Even if the flux melts during combustion, deterioration of the insulating film can be eliminated, and the molten low-melting metal wire can be brought into contact with the molten flux during operation to increase the interfacial energy of the molten metal. Therefore, quick fusing operability can be guaranteed.

In particular, in the inventions according to claims 2 and 3, since the connector is used for the serial connection of the parallel low melting point fusible metal wires, when the equipment normally burns, the metal plate of the serial connection part ( The operation due to fusing of the adjacent low melting point fusible metal wire due to the large amount of heat received from the heat receiving plate) can be reliably eliminated, and the concave strips for accommodating the low melting point fusible metal wire are parallel straight lines. Since it is possible to eliminate the recoil of metal plate, the occurrence of cracks, etc. due to the complicated processing strain in the bent portion,
Easy to make.

[Brief description of drawings]

FIG. 1A is a plan view showing an example of a metal plate used in the present invention, and FIG. 1B is a cross-sectional view taken along line B-B of FIG.

FIG. 2 is a perspective view showing another example of the metal plate used in the present invention.

3 (A) is a plan view showing a first insulating plate member of a connector used in the present invention, and FIG. 3 (B) is a plan view showing a second insulating plate member. 3C is a sectional view taken along the line of FIG. 3B, and FIG. 3D is a sectional view taken along the line II of FIG.

4 (a) is a side view showing a rivet used in the present invention, and FIG. 4 (b) is a cross-sectional view taken along line (b) of FIG. 4 (a).

5A to 5D are explanatory views showing an embodiment of the present invention in a manufacturing process, FIG. 5E is a sectional view taken along the line HO in FIG. 5C, and FIG. (F) and FIG. 5 (g) are a cross-sectional view and a cross-sectional view of FIG. 5 (d).

FIG. 6 is an explanatory diagram showing a main part of another embodiment of the present invention.

FIG. 7 is a sectional explanatory view showing a usage state of the sheet temperature fuse according to the present invention.

8 (A) is an explanatory view showing a conventional example, and FIG. 8 (B) is a cross-sectional view taken along line 8 (B) of FIG.

FIG. 9 is an explanatory diagram showing another conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Metal plate 11 Insulating film 13 Recessed line 21,22 2nd insulating plate member 211,221 Notch part b hole 31,32 1st insulating plate member 311,321 Bridge conductor c Connector-5 Flax 6 Flux containing Low melting point soluble metal wire 8 Sealing resin 81 Sealing resin

Front page continued (72) Inventor Yasuhiko Tomitaka 1-1-11 Shimanouchi, Chuo-ku, Osaka Uchihashi STEC Co., Ltd. (72) Inventor Maruaki 5-29-19 Shiba, Minato-ku, Tokyo Nihon Gas Equipment Inspection Association

Claims (3)

[Claims] 1. A flux-containing low melting point fusible metal, wherein a metal plate having an insulating film on at least one side thereof is provided with a groove having a predetermined pattern on one side thereof, and a flux is present in the hollow holes of the hollow low melting point fusible metal wire. A sheet-like temperature fuse characterized in that a wire is housed in the groove and the sealing resin is molded in the groove. 2. A low melting point fusible metal wire containing a flux, wherein a plurality of recessed lines are provided on one side of a metal plate having an insulating film on at least one side, and flux is contained in the hollow holes of the hollow low melting point fusible metal wire. It is housed in each of the above-mentioned grooves, these flux-containing low melting point fusible metal wire groups are connected in series by a connector, and a sealing resin is molded in each of the above-mentioned grooves. Sheet temperature fuse. 3. A first insulating plate member having a bridging conductor for connecting the low melting point fusible metal wires in series on one surface thereof is in contact with the other surface of the second insulating plate member. The laminated body is fixed to one surface of the metal plate on the other surface of the first insulating plate member to provide a connector, and each low melting point fusible metal wire end is soldered to the bridge conductor of the first insulating plate member. 3. An electrical connection made by being attached or welded.
The described sheet temperature fuse.