JPH0945200A - Thermal fuse device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the assembling property and simplify the wiring process by fitting and supporting multiple thermal fuses connected in series to a single fitting member. SOLUTION: Thermal fuses 35, 36 connected in series are fitted to a single fitting member 50. The fitting member 50 is provided with a hold section 51 having a rectangular cross section and capable of surrounding insulating protective tubes 48, 48 and fuses 35, 36. The tubes 48, 48 and fuses 35, 36 are inserted and fitted into the hold section 51 so that the heat received by the hold section 51 can be nearly uniformly transmitted to two fuses 35, 36. Since the fuses 35, 36 are aligned in parallel and fitted to the fitting member 50, wiring lead wires 46, 46 are guided in parallel from the same position, the wiring process is simplified, and the assembling property can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooking device such as a rice cooker, an electric pot and a hot plate, a heating device such as a fan heater and an electric stove, or an electric device including a heating device such as a clothes dryer as a safety means. The present invention relates to a temperature fuse device to be provided.

[0002]

2. Description of the Related Art Generally, in an electric device equipped with a heating device, for example, if a control circuit for controlling the heating device fails, the temperature of each part rises above a normal temperature, causing deformation of plastic parts and smoke emission of the electric device. In the worst case, there is a risk of ignition.

Therefore, as a safety measure for preventing the danger, a temperature fuse which operates by a change in temperature is connected in series in the energizing circuit of the heating device, and when the temperature in the electric equipment rises above a predetermined temperature, The operation of the temperature fuse is configured to cut off the energization of the heating device.

In recent years, for the purpose of enhancing reliability as a safety measure, a plurality of temperature fuses are connected in series in the energizing circuit of the heating device, and even if one of the temperature fuses fails, another Safety is ensured by the operation of the remaining thermal fuses.

[0005]

However, when a plurality of temperature fuses are used as described above, conventionally, each temperature fuse is individually attached to a predetermined portion using a mounting member corresponding to each temperature fuse. Therefore, the assemblability is poor and the wiring process is complicated.

The temperature fuse is provided with a single wire lead wire at both ends thereof, and when a plurality of temperature fuses are connected in series, the single wire lead wires are connected to each other by using a crimp type connection terminal. .

However, when the single lead wires are connected to each other by using the crimp type connection terminals, the crimp portion of the lead wires is plastically deformed, and the risk of disconnection increases when elasticity is lost and tension is applied during wiring. Further, if the lead wires are connected to each other by a single wire, the contact area is small, the contact resistance is large, and heat is generated, and this heat generation increases the risk that the thermal fuse malfunctions.

When the entire connected thermal fuse is covered with an insulating protection tube and the connecting portion is bent, it is difficult to confirm the position of each thermal fuse, and therefore the workability of the bending deteriorates.

[0009]

In order to solve such a conventional problem, the present invention mounts and supports a plurality of temperature fuses connected in series on a single mounting member. . Each thermal fuse has a single lead wire at both ends, and one lead wire of one thermal fuse and one lead wire of the other thermal fuse are connected via a multi-wire lead wire having an insulating coating structure. The multi-wire lead wire and the lead wire of each temperature fuse are connected using a crimp type connection terminal, and the middle portion of the multi-wire lead wire is bent and wired.

Further, an insulating protection tube is provided for each thermal fuse to cover the connection terminal portion from the thermal fuse, and the middle portion of the multi-wire type lead wire derived from these insulating protection tubes is bent.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 4 shows an electromagnetic induction heating type rice cooker as an example of an electric device equipped with a heating device. Reference numeral 1 is an outer frame, and the outer frame 1 is made of synthetic resin in a bottomed tubular shape. An inner frame 2 is provided.

Induction coils 4 and 5 are attached to the outer bottom surface side of the inner frame 2 with a coil base 3 therebetween, and the induction coils 4 and 5 are covered with a ferrite cover 6 which prevents leakage of magnetic flux. An opening 7 is formed in the center of the bottom surface of the inner frame 2, and a pan sensor 8 composed of a negative characteristic thermistor or the like is attached to the center of the bottom surface of the coil cover 3, and the pan sensor 8 passes through the opening 7. It projects to the inner bottom of the inner frame 2.

A pot 10 for cooking rice is housed inside the inner frame 2 in a removable manner. A flange portion 11 that is bent outward is integrally formed on the opening edge portion at the upper end of the pot 10, and the flange portion 11 is hooked on the opening edge portion at the upper end of the inner frame 2, whereby the pot 10 is formed. It is supported in the inner frame 2. A predetermined gap is secured between the outer surface of the pot 10 and the inner surface of the inner frame 2.

A lid 1 is provided on the upper surface of the outer frame 1 via a hinge 9.
The lid 2 is rotatably attached, and the lid packing 13 and the inner lid 14 are attached to the lower surface of the lid body 12, and the opening at the upper end of the pot 10 is opened and closed by the inner lid 14.

A vapor port 16 for discharging steam to the outside is formed in the lid 12, and a lid heater 17 made of a code heater or the like for heating the lower surface of the lid 12 and a negative characteristic server for detecting the temperature of the lower surface. A lid sensor 18 made of a mister or the like is provided. A body heater 19 made of a cord heater or the like is provided on the outer periphery of the inner frame 2.

Control boards 20 and 21 are provided inside the outer frame 1, and an inverter circuit for supplying a high frequency current to the induction coils 4 and 5 is provided on the control boards 20 and 21.

The pot 10 is composed of a pot body 25 made of a non-magnetic metal material and a heating layer member 26 made of a magnetic metal material provided in a portion extending from the bottom surface of the pot body 25 to the lower side surface.

A heating layer member 2 made of a magnetic metal material
6 is opposed to the induction coils 4 and 5 provided on the inner frame 2 at a predetermined interval, and the pan sensor 8 is in contact with the central portion of the outer bottom surface of the pan 10. The temperature of is detected.

Thermal fuse devices 30, 30 are provided on the bottom and top of the inner frame 2, respectively. These temperature fuse devices 30 and 30 operate when the temperature around them rises above a predetermined temperature to cut off the supply circuit of the high frequency current to the induction coils 4 and 5.

Reference numeral 31 is an operation panel provided on the upper surface of the lid body 12, 32 is a clamp mechanism that removably engages the lid body 12 with the outer frame 1, and 33 is provided on the outer bottom portion of the outer frame 1. The cord reel mechanism 34 is a power cord led out from the cord reel mechanism 33.

When using the rice cooker, the control board 2
A high-frequency current is supplied to the induction coils 4 and 5 by a control circuit such as an inverter circuit of 0 and 21, and an alternating magnetic field is generated in the induction coils 4 and 5 by the high-frequency current. Accordingly, the pan 10 placed in the magnetic field is generated. An eddy current flows through the heat generating layer member 26, and Joule heat due to this eddy current causes the heat generating layer member 26 to generate heat, and this heat is conducted to the pan body 25, whereby the pan 1
The contents of 0, namely rice and water, are heated.

The temperature of the pan 10 is sequentially detected by the pan sensor 8, and the heating amount of the pan 10 is adjusted according to a preset control sequence according to the detected temperature, and the rice is cooked or kept warm by this adjustment.

The non-magnetic metal material forming the pan body 25 of the pan 10 is aluminum, which has good heat conduction and is lightweight, and the magnetic metal material forming the heating layer member 26 is ferritic stainless steel. Has been.

Next, the structure of the thermal fuse device 30 will be described with reference to FIGS. As shown in FIG. 3, the thermal fuse device 30 is configured by connecting, for example, two thermal fuses 35 and 36 in series. The operating temperature (fusing temperature) of these temperature fuses 35 and 36 is, for example, 1 for both.
52 ° C, or 150 ° C for one and 15 for the other
Set to 2 ° C. When the pot 10 continues to be heated to an abnormal temperature due to a failure of the control circuit of the control boards 20 and 21, at least one of the temperature fuses 3
5 and 36 operate and induction coils 4,5 serving as heating means
It is designed to cut off the supply of current to the.

Each thermal fuse 35, 36 has a diameter of 4 mm.
A fuse element 41 is provided in a tube case 40 of a certain size, and the tube case 40 is used as a charging part, and the diameter is 1.0 to 1.
The lead wires 42 and 43 of about 5 mm are attached.

One lead wire 42 of one thermal fuse 35 and one lead wire 42 of the other thermal fuse 36.
Are connected to each other via a multi-wire lead wire 44 having an insulating coating structure. The lead wire 44 is obtained by bundling 20 filament wires having a diameter of 0.18 mm and having a cross-sectional area of about 0.5 mm ² and coating the outer circumference of the core wire with an insulating layer such as silicone rubber, and further, the outer surface of the insulating layer is made of glass fiber The structure is protected by.

The core wire of the lead wire 44 is connected to one of the lead wires 42, 42 of the thermal fuses 35, 36 by crimp type connection terminals 45, 45 made of oxygen-free copper.
Connected through.

The other lead wire 43 of the one temperature fuse 35 and the other lead wire 43 of the other temperature fuse 36 have lead wires 46 for wiring to the control circuit.
46 are connected. These lead wires 46, 46 are
Similar to the lead wire 44, 20 filament wires each having a diameter of 0.18 mm are bundled and the outer circumference of the core wire having a cross-sectional area of about 0.5 mm ² is covered with an insulating layer such as silicone rubber. It has a multi-wire insulation coating structure protected by glass fibers. Then, these lead wires 46,
The core wire of 46 is connected to the other lead wires 43, 43 of the thermal fuses 35, 36 via connection terminals 47, 47 made of crimp-type oxygen-free copper, respectively.

The thermal fuses 35 and 36 are covered with insulating protective tubes 48 and 48, respectively. These insulating protection tubes 48, 48 have a structure in which the outer surface of an insulating layer made of silicone rubber is protected by glass fibers. The insulating protection tubes 48, 48 extend to both sides of the thermal fuses 35, 36 and connect to the connection terminals 45, 47.
It is arranged so as to overlap a part of the lead wires 44 and 46 connected via the.

The lead wire 44 connecting the one temperature fuse 35 and the other temperature fuse 36 is almost 1 in the middle thereof.
The insulation protection tube 48 of one temperature fuse 35 and the insulation protection tube 48 of the other temperature fuse 36 are aligned parallel to each other by being bent in an arc shape of 80 °.

The total length of the lead wire 44 is, for example, 25 mm. For example, the length of the bent portion is 15 mm, the length of the portion overlapping the insulating protective tubes 48, 48 is 5 mm, or the length of the bent portion is Is 5 mm, and the length of the portion overlapping the insulating protection tubes 48, 48 is 10 mm. The length of the overlapping portion of the lead wires 46, 46 for wiring and the insulating protection tubes 48, 48 is about 5 to 10 mm.

Thermal fuses 35 and 36 arranged in parallel
Is a single mounting member 5 as shown in FIGS.
Attach to 0. The mounting member 50 is an insulating protective tube 4
8 and 48 and the thermal fuses 35 and 36 are provided with a holding section 51 having a rectangular cross section.
The insulation protection tubes 48 and 48 and the thermal fuses 35 and 36, which are aligned in parallel with each other, are inserted and mounted, and the heat received by the hold portion 51 is applied to the two thermal fuses 35 and 36.
It is arranged so that they can be transmitted to the 36 almost evenly.

As the material of the mounting member 50, for example, a zinc steel plate, an aluminum plate, or the like, which has heat resistance equal to or higher than the operating temperature of the thermal fuses 35, 36, good heat conduction, and excellent corrosion resistance, is used. Also, the mounting member 5 has a mounting hole 5
2 is formed, and a set screw (not shown) can be inserted into the mounting hole 52 to fix the mounting member 50 to a predetermined portion, that is, the inner frame 2 of the rice cooker.

In such a thermal fuse device 30, since a plurality of thermal fuses 35 and 36 are mounted and supported by a single mounting member 50, the assembling property is good and the wiring process is simple. In particular, in the embodiment shown in FIGS. 1 and 2, since the temperature fuses 35 and 36 are aligned in parallel and attached to the attachment member 50, the lead wires 46 and 46 for wiring are led out in parallel from the same location. Further, the wiring process is further simplified and the assembling property is improved.

The single lead wires 42 and 43 in the thermal fuses 35 and 36 are connected to the multi-wire lead wires 44 and 46 through crimp type connection terminals 45 and 47. Therefore, in the case of connecting the single wires to each other. As described above, it is possible to prevent the risk that the crimping portion is plastically deformed, loses elasticity, and is broken due to the tension at the time of wiring, and the contact area becomes larger than in the case of connecting single wires, It is possible to prevent an increase in resistance due to insufficient contact, and it is possible to prevent malfunction of the thermal fuses 35 and 36 due to heat generation at the connection portion.

When the connection between the thermal fuses 35 and 36 is bent, the bent portion is the middle of the flexible multi-wire lead wire 44.
The single lead wires 42, 42 in 36 can be easily bent without applying unnecessary force, and no force is applied to the thermal fuses 35, 36.
The reliability can be improved without damaging 36.

The length of the lead wire 44 connecting the temperature fuses 35 and 36 is the same as that required for bending the lead wire 44.
The insulating protection tubes 48, 48 are of a length for insulation that overlaps with each other, and therefore the length does not unnecessarily increase. Also, the insulation protection tubes 48, 48 are prevented from moving by the bent portions of the lead wires 44. Therefore, it is possible to prevent the exposed parts of the charging terminals such as the connection terminals 45 and 47 from the insulating protection tubes 48 and 48.

The thermal fuses 35 and 36 are individually covered with insulating protection tubes 48 and 48, and therefore, when the lead wire 44 is bent, the ends of the insulating protection tubes 48 and 48 can be bent as guides, and The position of the bent portion becomes clear, workability is improved, and the bending can be performed without the trouble of re-folding to correct the position.

5 and 6 show a modification of the mounting member 50. In this case, the mounting member 50 has a holding portion 51 having a rectangular cross section that is long in the vertical direction. Insulation protection tube 4 aligned in parallel
8, 48 and the thermal fuses 35, 36 are inserted and attached.

7 and 8 show another modification of the mounting member 50. The mounting member 5 in this case is shown in FIG.
0 has a holding portion 51 having a U-shaped cross section,
The holding portion 5 has an opening 54 at one end.
Tongue pieces 53, 53 are formed on the lower end edge of 1. The insulating protection tubes 48, 48 and the thermal fuses 35, 36 that are aligned in parallel are arranged inside the hold portion 51, the insulating protection tubes 48, 48 are inserted into the opening 54, and the tongue pieces 53, 53 is caulked inside so as to surround the insulating protection tubes 48, 48 and the thermal fuses 35, 36.

The present invention is not limited to the case of two thermal fuses, but may be a case of connecting three or more thermal fuses in series, and the thermal fuses may be connected in series. In addition to the case where the connection is bent by 180 °, the connection may be bent at an angle of 90 °.

[0042]

As described above, according to the present invention,
Safety can be reliably increased by multiple temperature fuses, assembly is easy, wiring processing is simple, and the temperature fuse lead wire and the connecting and wiring lead wires are stabilized by crimp type connection terminals. And connect securely,
Further, there is an advantage that the connection portion between one thermal fuse and the other thermal fuse can be bent easily and accurately without applying excessive force to the thermal fuse.

[Brief description of drawings]

FIG. 1 is a perspective view of a thermal fuse device according to an embodiment of the present invention.

FIG. 2 is a sectional view of the thermal fuse device.

FIG. 3 is a cross-sectional view showing a mutual connection structure of the thermal fuses in the thermal fuse device.

FIG. 4 is a cross-sectional view showing the structure of an electromagnetic induction heating type rice cooker.

FIG. 5 is a perspective view showing a modified example of a mounting member in the thermal fuse device.

FIG. 6 is a sectional view of the modification.

FIG. 7 is a perspective view showing still another modified example of the attachment member in the thermal fuse device.

FIG. 8 is a sectional view of the modification.

[Explanation of symbols]

 30 ... Thermal fuse device 42, 43 ... Single lead wire 44, 46 ... Multi-wire lead wire 45, 47 ... Connection terminal 48 ... Insulation protection tube 50 ... Mounting member

Claims (3)

[Claims] 1. A thermal fuse device comprising a plurality of thermal fuses connected in series, wherein the thermal fuses are mounted and supported by a single mounting member. 2. Each thermal fuse has a single lead wire at both ends thereof, and one lead wire of one thermal fuse,
One lead wire of the other thermal fuse is connected via a multi-wire lead wire with an insulation coating structure, and the multi-wire lead wire and the lead wire of each thermal fuse use crimp type connection terminals. 2. The multi-wire type lead wire is bent and bent in an intermediate part to be connected.
Thermal fuse device according to. 3. An insulating protection tube is provided for each thermal fuse to cover the connection terminal portion from the thermal fuse, and an intermediate portion of a multi-wire lead wire derived from these insulating protection tubes is bent. Claim 2 characterized by the above-mentioned.
Thermal fuse device according to.