JP3400157B2 - Solenoid valve and safety device for cooker using solenoid valve - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a solenoid valve which is arranged in a gas supply passage and controls the supply thereof, and a safety device which is provided in a cooker such as a gas table stove or a gas rice cooker using the solenoid valve. Regarding

[0002]

2. Description of the Related Art An electromagnetic valve has a structure in which a valve element urged in a valve closing direction is forcibly opened by a manual operation and held by suction, and is used particularly in a safety device for the cooking device. In this case, in addition to opening the gas passage by turning on the ignition switch, in addition to the thermocouple located near the burner head and the thermistor located in the pan bottom, the flame disappears and the pan bottom It functions as a safety valve that automatically closes due to overheating. For example, in JP-A-6-26653, the thermocouple, a solenoid valve,
An invention of a gas control circuit in which a positive temperature-sensitive element whose resistance value increases as the temperature rises is connected in series is disclosed.
This is because the thermoelectromotive force of the thermocouple normally keeps the solenoid valve open, and when the flame goes out, the solenoid valve closes due to the decrease in thermoelectromotive force, shuts off the gas supply, and the pot bottom is overheated. When the set temperature of the temperature sensing element is reached, the resistance value increases and the energization amount decreases, and the solenoid valve is closed. On the other hand, an electronic circuit that detects the thermoelectromotive force of the thermocouple and the resistance value of the temperature sensitive element by connecting the same thermocouple and temperature sensitive element and the small current type solenoid valve separately to the electronic circuit for monitoring There is also a configuration in which the energization to the solenoid valve is turned off when the respective set values are reached.

[0003]

In the former gas control circuit, unless the room temperature resistance value of the temperature sensitive element is not more than about 30 mΩ, the solenoid valve is opened by the low thermoelectromotive force obtained when cooking on a low heat or a low heat. The valve cannot be held. However, the current performance of the temperature sensitive element does not satisfy the above requirements, resulting in problems such as ignition failure and deterioration of the throttle characteristic, which is not preferable in practical use. Further, the latter electronic circuit requires a large manufacturing cost for the control board and the like, which leads to an increase in the cost of the entire cooking device.

[0004]

Therefore, according to the present invention, by improving the solenoid valve itself, even if the room temperature resistance value of the temperature sensitive element is about 30 mΩ or more, the above-mentioned problems do not occur and the cost is low. obtained by allowing a suitable adoption of the safety device of the cooker, the solenoid valve first, one Keshi electromagnets
And two features into the ring, one of the two electromagnets, the
The fixed iron core fixed in the casing and the fixed iron core
A first electromagnet consisting of a wound winding layer and the other,
It is arranged facing the first electromagnet, and goes in the direction of the first electromagnet.
A movable iron core that can be moved back and forth and the movable iron core
It is wound in a non-contact manner, and the winding side is integrated with the casing side.
Between the first electromagnet and the second electromagnet as a second electromagnet consisting of
, A suction piece movable between the two is arranged, while
The valve element is integrally connected to the movable iron core to
Each of the two electromagnets can be independently excited, and the valve body can be held in the suction valve open state only when both electromagnets are excited. On the other hand, in the safety device for the cooker, the electromagnetic valve according to claim 1 is arranged so that the gas supply path is opened when the valve body is adsorbed and held, and one electromagnet is arranged near the burner. The electromagnet is connected to a thermocouple, and the other electromagnet is connected to an energization control circuit including a temperature-sensitive element whose electric resistance value changes according to a rise in the temperature of the bottom of the pan and a power source. The energization control circuit can be configured by connecting a PTC thermistor as a temperature sensitive element and a power supply in series. Further, the energization control circuit can be configured by adopting an NTC thermistor as a temperature sensitive element, and connecting a switch and a power source, which are turned off when the electric resistance value of the NTC thermistor falls below a predetermined value, in series.

[0005]

The electromagnetic valve has two electromagnets built in one casing, and the valve body is held by the adsorption open valve only when both electromagnets are excited. Can be configured. The safety device employing this solenoid valve connects the two electromagnets to the thermocouple and the energization control circuit separately to connect the thermocouple and the energization control circuit when the thermoelectromotive force of the thermocouple is obtained. 2 when the amount of electricity is obtained
Only when one of the two conditions is satisfied, the valve body of the solenoid valve is held by the suction valve open and the gas supply is continued. Therefore, when the flame is extinguished or the bottom of the pot is overheated, the energization to the electromagnet side is stopped, the excitation is released, the valve body is closed, and the gas supply is quickly cut off. The energization control circuit can be easily constructed by using the PTC thermistor or the NTC thermistor.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1A is an explanatory diagram of the magnet solenoid valve 1, in which a base body 4 around which a collar portion 3 is provided is fitted at one end of a cylindrical casing 2, and the base body 4 on the casing 2 side. Has
The base end of a U-shaped fixed iron core 6 around which the first winding layer 5 is wound is fitted and fixed to form a first electromagnet 7, and a pair of terminal fittings 8a and 8b are joined to the opposite side. . On the other hand, the other end of the casing 2 is a closed portion 2a,
The closed portion 2a is also provided with through holes 10 and 10 through which the U-shaped movable iron core 9 extends, and the number of windings is increased around the through holes 10 and 10 as compared with the first winding layer 5. A small current type second winding layer 11 is embedded to form a second electromagnet 12. Further, between the fixed iron core 6 and the movable iron core 9,
The ring-shaped movable piece 13 is arranged in a free state, and the movable piece 13 is inserted into the through hole 13a at the center of the closed portion 2a.
The guide portion 2b extending toward the fixed iron core 6 so as to coincide with the shaft center of the casing 2 penetrates to guide the sliding in the axial direction. Further, the movable iron core 9 is connected to the base end portion of the valve shaft 15 in the housing 14 connected to the casing 2, and the tip end portion of the valve shaft 15 is connected to the housing 1.
4 and a valve body 16 is integrally provided outside thereof and is urged toward the tip end side (right side in FIG. 1A) by a compression spring 17 provided between the valve body 16 and the housing 14. .

The magnet solenoid valve 1 thus constructed
In the state where both the first winding layer 5 and the second winding layer 11 are not energized, the movable core 9 is moved to the position of FIG. 1 (A) together with the valve shaft 15 and the valve body 16 by the bias of the compression spring 17. The movable piece 13 is also in a free state. Here the valve body 1
6 is forcibly retracted to a position where the movable core 9 and the movable piece 13 come into contact with the fixed iron core 6 and stop by manual operation or the like.
When both the first winding layer 5 and the second winding layer 11 are energized,
Since the excited first electromagnet 7 and second electromagnet 12 both attract the movable piece 13, as shown in FIG.
Is attracted to the fixed iron core 6, and the movable iron core 9 also maintains a position where it is attracted to the movable piece 13 against the bias of the compression spring 17. Therefore, the valve body 16 is also held in the retracted position, and the valve open state is maintained. If the energization of only the first winding layer 5 is stopped from this state, the excitation of the first electromagnet 7 is released and the movable piece 13 separates from the fixed iron core 6, but the second electromagnet 12
Since the excitation is continued, the movable iron core 9 returns to the position shown in FIG. 1C together with the valve shaft 15 and the valve body 16 by the bias of the compression spring 17 while the movable piece 13 is attracted. On the contrary, when the energization of only the second winding layer 11 is stopped,
As shown in (D), only the movable core 9, the valve shaft 15, and the valve body 16 are returned to their original positions by the compression spring 17 while the movable piece 13 is adsorbed to the fixed core 6. As described above, the magnet solenoid valve 1 has two electromagnets built therein with a simple structure, and each of them is associated with the operation of one valve element as described above. A suitable effect can be obtained by providing it in a gas control circuit such as a water heater or a cooker. The following shows an example of application in a cooker such as a gas table stove or rice cooker.

FIG. 2 is a schematic view of a gas table stove. The magnet solenoid valve 1 is incorporated in the blinker body 20 as in the conventional case, and the spindle of the main valve 22 which opens and closes in conjunction with the operation of the ignition button 21. The tip of 23 is located at the position of the valve body 16 that closes the valve seat 24 in the non-energized state, and the valve body 16 is also retracted when the spindle 23 is pushed. Further, the first winding layer 5 of the first electromagnet 7 in the magnet solenoid valve 1 is connected to the thermocouple 26 installed near the burner head 25 to form a thermocouple circuit 26a as shown in FIG. The second winding layer 11 of the second electromagnet 12 is provided in contact with the central portion of the bottom surface of the pot or the like placed on the stove part, and has a positive characteristic PTC that rapidly increases the resistance value at the set temperature as the temperature rises. The thermistor 27, the switch 21a that works with the ignition button 21, and the dry battery 18 are connected in series, respectively, to form an energization control circuit 27a. Reference numeral 28 is a burner body, and 29 is a gas inlet.
Therefore, in the above safety device, at the time of ignition, the spindle 23 is pressed by the pushing operation of the ignition button 21 (direction of arrow a in FIG. 2) to open the main valve 22, and at the same time, the valve body 16 of the magnet electromagnetic valve 1 is also rotated by the spindle 23. Is pushed into the tip of the valve seat 24 and separated from the valve seat 24 to open the gas passage to the burner body 28. After that, the thermocouple 2 which detected the flame
With the thermoelectromotive force of 6, the thermocouple circuit 26a is energized to excite the first electromagnet 7 and the second electromagnet 12 is also energized by the energization of the energization control circuit 27a.
The state of (B) is maintained and the gas supply is continued. When the flame is extinguished in the burner head 25 from this state, the energization of the first winding layer 5 by the thermocouple 26 is stopped, so that the excitation of only the first electromagnet 7 is released. And the valve body 1 returned to its original position.
Reference numeral 6 closes the valve seat 24 to shut off the gas passage, and the fire is automatically extinguished. On the other hand, when the pot bottom temperature rises and the PTC thermistor 27 reaches the set temperature, the amount of electricity to the second winding layer 11 decreases due to the increase in the resistance value, so that the excitation of only the second electromagnet 12 is released. It becomes the state of (D),
In this case as well, the valve body 16 that has been returned closes the gas passage to automatically extinguish the fire. As described above, according to this safety device, since the magnet solenoid valve 1 is adopted, the thermocouple and the PTC thermistor can be used without significantly changing the design of the structure of the blinker or using a complicated control board or the like. A highly reliable safety device can be configured by simple connection with. Further, since the PTC thermistor and the thermocouple are separately connected, even those having a high room temperature resistance value can be used without problems such as ignition failure and deterioration of throttle characteristics.

The energization control circuit may be constructed by using the PTC thermistor 27 or by adopting a negative NTC thermistor whose resistance value decreases as the temperature rises. For example, as shown in FIG. 4, an energization control circuit 19 including a comparison circuit 34 connected to the NTC thermistor 19 to detect the resistance value thereof, and a switch 35 opened and closed by the comparison circuit 34.
It suffices to configure a, and the comparison circuit 34 turns off the switch 35 when the resistance value that decreases as the pot bottom temperature rises decreases to a predetermined value.

On the other hand, the solenoid valve is such that the valve element retracted only when both of the two adjacent electromagnets are excited is adsorbed and held, and when at least one of the electromagnets is deenergized, the holding is released. Therefore, various design changes can be made without departing from the spirit of the invention. For example, as shown in FIG. 5, an iron core 30 integrally provided with four adsorption portions 31, 31, ... Of equal length is fixed in a housing 32, and the first winding layer is attached to each of the adsorption portions 31, 31 on the left and right sides. 5. The second winding layer 11 is wound to form the first electromagnet 7 and the second electromagnet 12, and at the same time, the attraction piece 33 that can simultaneously contact the four attraction portions 31 is connected to the valve shaft 15. Then, also at this time, the attraction piece 33 is attracted against the bias of the compression spring 17 only when both the first and second electromagnets 7 and 12 are excited. When the excitation of one of the electromagnets is released, the attraction of the other piece continues and the attraction piece 33 is inclined as shown by the chain double-dashed line. A separating force is applied, and the separating piece 33 also separates from the other electromagnet and the adsorption piece 33 returns to its original position. Therefore, the magnet solenoid valve 1a of this modification also has the same function as that shown in FIG. 1A, in which the first winding layer 5 is on the thermocouple side and the second winding layer 11 is the energization control circuit. If connected to the side, a safety device can be easily configured.

Further, a modified example as shown in FIG. 6 can be considered. This employs an N-shaped iron core 30a fixed to a housing 32a, and winds the first winding layer 5 around one suction portion 31a and the second winding layer 11 around the other suction portion 31b.
0a is sandwiched between the suction pieces 33a and 33b, and the valve shaft 1
5, 15 and valve bodies 16, 16 are provided respectively.
According to this magnet solenoid valve 1b, when both the first electromagnet 7 and the second electromagnet 12 are excited with the valve bodies 16 and 16 being pushed, the attraction pieces 33a and 33b are attracted to each other by the iron core 30a. When the energization of the one winding layer 5 is stopped, the attraction piece 33b on the second electromagnet 12 side is left as it is, and only the attraction piece 33a on the first electromagnet 7 side is returned to the original position by the bias of the compression spring 17. On the contrary, when the energization of the second winding layer 11 is stopped, only the attracting piece 33b on the second electromagnet 12 side is separated. Therefore, this magnet solenoid valve 1b
If the valve element is arranged so as to close the gas passage when at least one of the adsorption pieces is not adsorbed, a safety device that functions in the same manner as described above can be configured. Of course, when applied to other circuits, both sides need not be valve bodies.

[0012]

As described above, the solenoid valve of the present invention is a single casing.
By installing two electromagnets inside the unit, it is suitable for safety devices of cooking devices, and the room temperature resistance value of the temperature sensing element is 30 m.
Even if it is about Ω or more, there is no problem such as the influence of the thermal power on the throttle characteristic, and it can be easily applied at low cost. In particular, because they constitute employ fixed iron core and the movable iron core or the like, a less simple structure of design changes. Also as the safety device, a simple connection between the thermocouple and the energization control circuit using the temperature sensitive element can reliably extinguish the burner when the flame goes out and the set temperature of the pot bottom or the like is reached. A highly efficient device can be obtained. Further, if the energization control circuit uses a PTC thermistor or an NTC thermistor, the safety device can be more simply constructed.

[Brief description of drawings]

FIG. 1A is an explanatory diagram of a magnet solenoid valve. (B) It is explanatory drawing which shows the operating state of a magnet solenoid valve. (C) It is explanatory drawing which shows the operating state of a magnet solenoid valve. (D) It is explanatory drawing which shows the operating state of a magnet solenoid valve.

FIG. 2 is a schematic view of a gas table stove to which the magnet solenoid valve is applied.

FIG. 3 is a circuit diagram of a safety device.

FIG. 4 is a circuit diagram showing a modification example of an energization control circuit in the safety device.

FIG. 5 is an explanatory diagram showing a modified example of a magnet solenoid valve.

FIG. 6 is an explanatory diagram showing a modified example of a magnet solenoid valve.

[Explanation of symbols]

1 ... Magnet solenoid valve, 2 ... Casing, 3 ... Collar part, 4 ... Base body, 5 ... First winding layer, 6 ... Fixed iron core,
7 ... First electromagnet, 8 ... Terminal metal fittings, 9 ... Movable iron core,
10 ... Through hole, 11 ... Second winding layer, 12 ... Second electromagnet, 13 ... Movable piece, 14 ... Housing, 15 ... Valve shaft, 16 ... Valve element, 17 ... Compression spring , 18 ...
Dry battery, 19 ... NTC thermistor, 20 ... Blinker body, 21 ... Ignition button, 22 ... Main valve, 23 ...
Spindle, 24 ... Valve seat, 25 ... Burner head, 2
6 ... Thermocouple, 27 ... PTC thermistor, 28 ... Burner body, 29 ... Gas inlet, 30 ... Iron core, 31 ...
Adsorption part, 32 ... Housing, 33 ... Adsorption piece, 34 ...
・ Comparison circuit, 35 ・ ・ Switch.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-307631 (JP, A) JP-A-6-26653 (JP, A) JP-A 52-111024 (JP, A) JP-B 57- 61958 (JP, B1) JP-B 47-48972 (JP, B1) JP-B 57-61957 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) F16K 31/06-31 / 11 F24C 3/12

Claims (4)

(57) [Claims] 1. A solenoid valve for forcibly opening a valve element biased in a valve closing direction by a manual operation or an electric driving force, and holding the valve open by adsorption by exciting an electromagnet. Two are installed side by side in one casing , and the two electromagnetic
A fixed iron core in which one of the stones is fixed in the casing
And a winding layer wound around the fixed iron core.
Magnet, and the other is placed facing the first electromagnet.
And a movable iron provided so as to be movable back and forth in the direction of the first electromagnet.
It is wound around the core and its movable iron core without contact, and on the casing side.
A second electromagnet consisting of a winding layer integrated with
Between the electromagnet and the second electromagnet, a suction piece that can move between them
, While the movable iron core is integrally connected to the valve body.
In combination, the first and second electromagnets can be independently excited, and the valve body can be held by adsorption and opening only when both electromagnets are excited. 2. The electromagnetic valve according to claim 1 is arranged in a gas supply passage, and the gas supply passage is opened when the valve body holds the adsorption valve. This electromagnet is connected to a thermocouple arranged near the burner, and the other electromagnet is connected to an energization control circuit equipped with a temperature sensitive element and an electric power source whose electric resistance value changes depending on the temperature rise of the bottom of the pan. A safety device for a cooking device that uses a solenoid valve. 3. The energization control circuit is configured by connecting a PTC thermistor whose electric resistance value rapidly increases at a set temperature due to temperature rise and a power supply in series.
2. A safety device for a cooker using the solenoid valve according to 2 . 4. The energization control circuit includes an NTC thermistor whose electric resistance value decreases in accordance with a temperature rise, and the NC thermistor
The safety device for a cooker using a solenoid valve according to claim 2 , wherein a switch that is turned off when the electric resistance value of the TC thermistor falls below a predetermined value and a power source are connected in series.