JPH10137120A - Safety device for abnormal overheating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a safety device which enables inexpensive manufacturing thereof with a better response by a method a retaining body made of hot melt material for preventing abnormally heating condition is provided at a connection part between an attraction part and a link part, melts and opens a valve body when a set temperature is reached beyond a specified value to accurately sense a rise in the temperature of the bottom of a pot. SOLUTION: A sensor part 2 is provided with a cylindrical case 34 made of non- magnetic material at a part contacting the bottom surface of a pot 1 and a thermosensitive metal 3 is fixed at the center of the rear thereof in such a manner that its permeability lowers when the temperature reaches near a Curie temperature. An attraction part 5 is arranged facing the thermosensitive metal to attract or separate it, a link bar 11 is so arranged to vertically move integrally with the attraction part, and a valve is and a valve is arranged in the course of the link bar 11 to open or close a gas passage. Thus, when the temperature rises beyond the temperature at the completion of rice cooking, as caused, for example, when the attraction part 5 fails to separate from the thermosensitive metal 3 being stuck by foreign matters, a pin 6 begins to melt at a set temperature thereof and the link bar 11 is separated in the direction of closing by a valve spring force to close the gas passage.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device in the event of abnormal overheating, and more particularly to a safety device for detecting abnormal temperature of a pot bottom of a rice cooker, a cooking pot or the like to prevent abnormal overheating.

[0002]

2. Description of the Related Art Conventionally, rice cookers and cooking appliances have been provided with safety devices for preventing overheating. For example, a rice cooker is provided with a heat-sensitive element that contacts the bottom of the rice cooker and a permanent magnet attracting portion that comes into contact with and separates from the heat-sensitive element. A gas valve is provided to close the valve. That is, when the bottom of the rice cooker reaches the rice cooking completion temperature (145 ° C.), the magnetic permeability of the heat-sensitive element decreases, and the biasing force of the spring overcomes the suction force between the heat-sensitive element and the suction portion, and separates. In conjunction with this, the gas valve shuts off the gas passage by the urging force of the spring, and the rice cooking is completed.

However, when foreign matter enters the suction surface between the heat-sensitive element and the suction part and is fixed and does not separate, or aged foreign matter is present in the gap between the suction part and the cylindrical case accommodating the suction part. If the adsorption portion is caught by the non-adhesion, the gas passage cannot be shut off even if the rice cooking is completed, and there is a possibility that abnormal heating may occur.

Therefore, for example, Japanese Patent Application Laid-Open No. 7-289425
As described in the publication, in order to prevent an inconvenience of an abnormal overheating state, all or a part of a connecting shaft connecting the adsorbing portion and the gas valve is made of a heat-fusible material (having a melting point of about 200 ° C. to 250
It is proposed that the lower end of the connection shaft and the swing lever that shuts off the gas passage be connected by a resin flange made of a thermoplastic material. In this case, when the connecting shaft becomes high temperature, the resin flange is softened and melted and broken, the swing lever is separated from the connecting shaft, and the gas valve linked with the swing lever is closed by the urging force of the spring. Then, the burner goes into a fire extinguishing state to prevent abnormal overheating.

[0005]

However, when the lower end of the connecting shaft and the swinging lever for shutting off the gas passage are connected by a resin flange made of a thermoplastic material, the heat radiation from the connecting shaft and the temperature of the connecting shaft itself are reduced. Due to the gradient, heat from the bottom of the pot is not easily conducted, especially when the adsorbing part detaches from the thermosensitive element and gets caught in the middle, a gap is formed between the thermosensitive element and the adsorbing part, making it difficult to conduct heat. Therefore, there has been a problem that the response as a safety device at the time of abnormal overheating is poor. Further, when a heat-fusible material is used for a part of the connecting shaft, there is a problem that it is difficult to manufacture the connecting shaft. Further, when the whole or a part of the connecting shaft is made of a heat-fusible material, the whole connecting shaft becomes a radiator, so that the temperature hardly rises and the operating temperature as a safety device is not stable. . The present invention solves the above problems, accurately detects the temperature rise at the bottom of the kettle, has good reactivity,
Moreover, it is an object of the present invention to provide a safety device at the time of abnormal overheating which can be manufactured at low cost.

[0006]

A safety device for abnormal overheating according to the present invention which solves the above-mentioned problems is provided by a temperature-sensitive metal having a Curie point at which heat is received from the bottom of the pot and when the temperature reaches a predetermined temperature, the magnetic permeability sharply decreases. Connecting a suction member facing and separating from the temperature-sensitive metal using a permanent magnet, a valve body biased in a direction to close a gas flow path to a burner, and connecting the suction portion and the valve body to each other. A connecting member that closes the valve body when the adsorbing section is detached from the temperature-sensitive metal, and forcibly abuts the adsorbing section on the temperature-sensitive metal by manual or electric drive during ignition. And a valve opening means for opening the valve body, and a connecting portion between the adsorbing portion and the connecting member is melted when a set temperature exceeding the predetermined temperature is reached. Disconnect the connecting member from the suction part and close the valve body. And summarized in that with a locking member of the heat-meltable material to prevent abnormal overheating.

The safety device at the time of abnormal overheating of the present invention having the above-mentioned structure is provided when the fixing member of the hot-melt material provided at the connecting portion between the adsorbing portion and the connecting member reaches a set temperature exceeding a predetermined temperature. Then, the connecting member is melted and separated from the adsorbing portion, and the valve body is closed to prevent an abnormal overheating state. Therefore, since the locking body of the heat-fusible material is provided at the connecting portion between the suction portion and the connecting member near the bottom of the pan, the temperature of the bottom of the pan is accurately transmitted, and the accuracy as a safety device at the time of abnormal overheating is improved. . Therefore, even if an abnormal situation occurs in which the adsorption section cannot be separated from the temperature-sensitive metal, an abnormal overheating state can be reliably prevented.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In order to further clarify the structure and operation of the present invention described above, a preferred embodiment of a safety device for abnormal overheating according to the present invention will be described below. FIG. 1 is a schematic configuration diagram of a rice cooker as one embodiment. At the center of the burner 14 of the rice cooker, a sensor unit 2 for detecting temperature is provided. The sensor section 2 is in contact with the bottom of the shuttle 1 placed on the burner 14 to detect the bottom temperature. Burner 14
Is provided with a thermocouple 9 which generates an electromotive force by combustion heat, facing the flame outlet.

The ignition button 19 which moves forward and backward by a pressing operation
Is provided in the casing 33 via the button spring 20, and a push-push mechanism 21 for determining the advance / retreat position of the ignition button 19 alternately between ignition and extinguishing is provided on the side surface of the ignition button 19. Further, an ignition switch 22 that is turned on / off in conjunction with the advance / retreat of the ignition button 19 is provided near the ignition button 19. The ignition switch 22
When the ignition button 19 is turned on at the ignition position, an igniter (not shown) is activated to ignite the fuel gas, and the ignition is stopped at 0FF at the combustion position and the fire extinguishing position.

The ignition button 19 advances by a pressing operation at the time of ignition (rightward in the drawing), and transmits the pressing operation to the casing 33 side with the lever 17 interposed therebetween. The spindle 23 is inserted into the casing 33 so as to be able to advance and retreat.
1 is urged to the left in the figure. On the spindle 23, a main valve 24 for opening and closing the main outlet 26 of the main body 33 and a small-diameter valve portion 28b for opening and closing the pilot outlet 27 for ignition are provided. Also, the main discharge port 26
The ignition pilot discharge port 27 is connected to the main nozzle 16 and the ignition pilot nozzle (not shown) of the combustion unit. At the rear of the casing 33,
A magnet safety valve 25 is provided coaxially with and facing the spindle 23. The magnet safety valve 25 is opened and held by the electromotive force of the thermocouple 9 provided on the burner 14, and when the electromotive force of the thermocouple 9 drops below a predetermined level,
The safety valve 32 is closed to close the gas flow path to the main discharge port 26 and the ignition pilot discharge port 27.

Next, FIG. 2 shows an enlarged view of the sensor section 2 for explanation. The sensor section 2 is provided with a non-magnetic cylindrical case 34 at a portion in contact with the bottom of the pot 1 of the pot 1, and at the center of the back surface of the cylindrical case 34, a temperature-sensitive metal whose magnetic permeability decreases when the temperature approaches the Curie temperature. 3 is fixed. Further, an adsorbing portion 5 that adsorbs and desorbs to face the temperature-sensitive metal 3, a connecting rod 11 that moves up and down integrally with the adsorbing portion 5, and a gas passage is opened and closed in the middle of the connecting rod 11. A valve 10 is provided (FIG. 1). The valve 10 is provided with valve springs 12a and 12b that urge the valve in the valve closing direction. The valve springs 12 (in the case where 12a and 12b are collectively referred to as springs 12) are connected to one end of a connecting rod 11. Is urged from the temperature-sensitive metal 3 in the separating direction. still,
As shown in FIG. 1, the gas flow path 15 after passing through the valve 10 is
It bypasses and leads to the gas flow path 18 of the casing 33.

The ignition button 1 is provided on the casing 33.
A lever 17 for transmitting the pressing operation force 9 to the suction unit 5 is provided. The ignition button 19 advances by a pressing operation at the time of ignition, and moves in a direction in which the suction portion 5 provided at the other end of the connecting rod 11 comes into contact with the temperature-sensitive metal 3 via the lever 17 (upward in the figure).

Further, the material of the temperature-sensitive metal 3 is made of ferrite or the like having a Curie temperature which is the temperature reached at the time of completion of rice cooking, and when the temperature becomes close to the Curie temperature, the magnetic permeability rapidly decreases. On the other hand, the material of the attraction unit 5 is made of a permanent magnet.

As shown in FIG. 3A, one end of the connecting rod 11 faces the holding case 4 for fixing the suction portion 5.
A cylindrical pin 6 made of a heat-fusible material is inserted into a hole of the connecting rod 11 facing the inside of the holding case 4, and the holding case 4 and the connecting rod 11 are connected by the pin 6. In this case pin 6
Since it is manufactured in a columnar shape, it can be easily manufactured and easily assembled. Further, a slide portion is provided at a connection portion between the holding case 4 and the connecting rod 11, and the suction portion 5 is moved by the pressing operation at the time of ignition.
After the contact, the slide portion is provided with a stroke absorbing spring 7 for absorbing an extra pressing stroke. Further, the stroke absorbing spring 7 includes the temperature-sensitive metal 3 and the suction portion 5.
It plays a role of absorbing the inclination of the suction unit 5 so that the suction surface of the suction unit 5 does not tilt but adheres.

Next, the operation of each part at the time of ignition / extinguishing will be described with reference to FIG. In the stopped state, the valve 10 is closed because the adsorption unit 5 is separated from the temperature-sensitive metal 3 and the main valve 2 is closed.
4. The small-diameter valve portion 28b is closed. In this state, when the ignition button 19 is pressed, the ignition button 19 advances against the button spring 20 (FIG. 1), and the spindle 23 is pushed rearward against the return spring 31 and the main valve 24 is pressed. , And the small-diameter valve portion 28b and the safety valve 32 are sequentially opened. Further, by the pressing operation on the ignition button 19, the suction portion 5 is pressed against the temperature-sensitive metal 3 via the lever 17. During this operation, the ignition switch 22 is turned on and the igniter of the combustion section starts operating. Then, by this series of operations, the raw gas is supplied to the combustion section via the main discharge port 26 and the pilot discharge port 27 for ignition, and is ignited by the igniter. Further, a current generated from the thermocouple 9 facing the combustion flame flows through the safety valve 32, and the electromotive force causes the safety valve 32 to be kept open.

On the other hand, the ignition button 19 advances due to the forward movement at the time of ignition, and the lever 17 which has already been described swings up to push up the connecting rod 11, and the suction part 5 provided at the other end of the connecting rod 11 is moved to the temperature-sensitive metal 3. Contact. When the suction portion 5 and the temperature-sensitive metal 3 come into contact with each other, the suction force overcomes the closing force of the valve spring 12 to maintain the valve 10 open. After the pressing operation, when the hand is released, the operation of the return spring 31 causes the spindle 23 and the ignition button 19 to close the small-diameter valve portion 28b while the main valve 24 is opened by the push-push mechanism 21 and to close the safety valve 32. The combustion is continued by returning to the position where the valve can be freely closed (the state shown in FIG. 1).

When the fire is extinguished, the user pushes and releases the ignition button 19 again so that the spindle 23 can be turned off.
Returns, and the main valve 24 closes to extinguish the fire.

Next, the overheating prevention function of the rice cooker will be described. When the temperature of the pot bottom reaches the rice cooking completion temperature (145 ° C.) during the combustion, the valve closing force of the valve spring 12 decreases due to the decrease in the magnetic permeability of the temperature-sensitive metal 3 and the temperature-sensitive metal 3 and the adsorbing section 5. And the adsorbing portion 5 is detached by overcoming the adsorbing force, and the valve 10 closes the gas passage to extinguish the fire. That is, when the temperature-sensitive metal 3 having the Curie point reaches a predetermined temperature (near the Curie temperature), the magnetic permeability rapidly decreases.
Is lost, and the suction portion 5 is separated. Then, when the adsorption section 5 and the temperature-sensitive metal 3 separate, the valve spring 12 closes the valve 10 and immediately stops the combustion.

Further, when the suction portion 5 and the temperature-sensitive metal 3 are fixed by the foreign matter or the like and are not separated, or when the holding case 4 of the suction portion 5 is separated from the temperature-sensitive metal 3 by the foreign material or the like, the cylindrical case is removed. If it is caught on 34, the valve 10 does not close, the combustion cannot be stopped, and the temperature further rises above the rice cooking completion temperature. In this case, as the temperature rises, the pin 6 made of the hot-melt material starts melting at the set temperature (175 ° C.), and the force of the valve spring 12 melts the softened pin 6 and faces the inside of the cylindrical case 34. The connecting rod 14 is cut off in the valve closing direction of the valve 10 to close the gas passage. Therefore, it is possible to stop an abnormal overheating state in which the pin 6 made of the heat-meltable material exceeds the rice-cooking completion temperature, thereby preventing a fire or the like from occurring.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and it is needless to say that the present invention can be carried out in various modes without departing from the gist of the present invention. It is. For example, the shape of the pin 6 connecting the holding case 4 and the connecting rod 11 is shown in FIG.
The disk-shaped washer 6b shown in (b) is not limited to the columnar one shown in (a). Further, as shown in (c), the holding case 4 itself for fixing the suction portion 5 may be made of a heat-fusible material, and the connecting rod 11 may be locked in a small hole provided at the center. Also, the heat-fusible material is
The material is not limited to a heat-meltable or thermoplastic resin, and may be a metal material such as lead that melts at a set temperature higher than the Curie point. Further, the manual operation of pushing the ignition button 19 is not limited to forcibly bringing the temperature-sensitive metal 3 into contact with the adsorbing portion 5 to adsorb the adsorbing portion 5 and opening the valve body 10. A configuration in which a solenoid for pushing the portion 5 is provided to open the valve body 10 may be used. Further, the embodiment of the present invention has been described as a device for preventing overheating when the rice cooker is abnormal,
It may be configured as a device for preventing overheating of cooking equipment such as a table stove when an abnormality occurs.

[0021]

As described above in detail, according to the apparatus for preventing overheating at the time of abnormality of the present invention, it is possible to accurately detect the temperature rise at the bottom of the kettle with a simple structure, to have good reactivity, and to manufacture it at low cost. It has an excellent effect.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a safety device at the time of abnormal overheating as one embodiment.

FIG. 2 is an enlarged view of a sensor unit according to the embodiment of the present invention.

FIG. 3 is a diagram showing another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hook 2 Sensor part 3 Temperature sensitive metal 4 Holding case 5 Suction part 6 Pin 7 Stroke absorption spring 9 Thermocouple 10 Valve 11 Connecting rod 12 Valve spring

Claims (1)

[Claims] 1. A temperature-sensitive metal having a Curie point at which heat is received from the bottom of the pot and rapidly decreases in magnetic permeability when the temperature reaches a predetermined temperature, an adsorbing portion which faces and separates from the temperature-sensitive metal using a permanent magnet, and a burner. A valve body urged in a direction to close a gas flow path to the valve, and connecting the suction portion and the valve body, and closing the valve body when the suction portion is separated from the temperature-sensitive metal. A connecting member, and valve opening means for forcibly abutting the suction portion on the temperature-sensitive metal by manual or electric drive to cause the suction portion to adsorb and to open the valve body at the time of ignition; When the temperature of the connecting portion between the adsorbing portion and the connecting member reaches a set temperature exceeding the predetermined temperature, the connecting portion is melted, the connecting member is separated from the adsorbing portion, and the valve body is closed to abnormally heat the valve. It is equipped with a locking body of hot-melt material to prevent the state Safety device at the time of abnormal overheating that.