JPS5835135Y2 - Heat retention type electric cooker - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a heat-retaining electric cooker that reduces thermal shock to rice, especially when keeping it warm.

In a heat-retaining electric cooker, which is generally referred to as an electric jar rice cooker, after rice cooking is completed, a heat-retaining heater attached to the inner surface of the lid or the outer wall of the outer pot that houses the inner pot is energized to heat the inner pot. The heat is insulated not only from the bottom but also from the top or sides.

In addition, recently, due to improvements in the mounting structure of the side heat-retaining heater due to cost and performance considerations, the need for a heat-retaining heater on the inside of the lid has been eliminated. It generates heat to heat the inner pot.

However, since the side heat retention heater is simply attached to the outer wall of the outer pot, thermal shock (significant temperature difference between high and low temperatures) may occur due to ON-OFF operation during heat retention, resulting in temperature unevenness. Ta.

This, in turn, significantly impeded heat retention and resulted in the inability to maintain delicious rice for a long period of time.

In addition, as mentioned above, in the case of a structure in which the heat-retaining heater on the inner surface of the lid is eliminated, the heat-retaining lid is heated to a high temperature because the upper periphery of the outer pot and the heat-retaining lid on the inner surface of the lid are brought into contact with each other in a state of good heat conduction. The surface of the overcooked rice became dry and dry, and the aforementioned heat shock also affected the heat-insulating lid, causing temperature unevenness.

Although this problem could be improved slightly by keeping the heat output of the heat-retaining heater low, it affected the overall temperature drop and made it impossible to maintain the optimum temperature for keeping rice at about 70°.

The present invention has been developed in view of the above points, and will be explained below with reference to the drawings. 1 is a cylindrical frame, 2 is a bottomed cylindrical frame with good thermal conductivity attached to the frame 1 with a heat insulating material 3 interposed therebetween. The outer pot is provided with a horizontal step 4 on the upper peripheral edge, forming a rising wall 5 extending further upward.

Reference numeral 6 denotes a ring-shaped frame cover made of heat-resistant synthetic resin that connects and fixes the upper peripheral edge of the outer pot 2 and the upper peripheral edge of the frame 1, and has a stepped portion 7 formed around the entire inner circumference and a stepped portion 7 around the entire upper circumference. A recessed portion 8 is formed.

Reference numeral 9 denotes a ring-shaped heat dissipation plate with good heat conduction, one end of which is placed in close contact with the inside of the rising wall 5 of the outer pot 2 and the other end of which is housed in the inner wall of the recessed portion 8. It is screwed and fixed to the upper surface of the frame cover 6 using a fixing device (not shown) such as the above.

When the heat sink 9 is fixed, a heat storage chamber 10 is formed between the step part 7 of the frame cover 6 and the rising wall 5 of the outer pot 2, and the heat storage chamber 10 is sealed all around.

Reference numeral 11 denotes a heat-retaining heater attached to the outside of the rising wall 5, and is located inside the heat storage chamber 10.

12 is a ring-shaped heating plate fixed to the inner bottom of the outer pot 2;
Reference numeral 13 denotes an inner pot which can be freely stored in the outer pot 2 and is placed on the heating plate 12 when stored, and a gap 1 is formed between it and the inner wall of the outer pot 2 when stored.

14 is the inner pot 13 with a steam hole 15.15 bored in the center side.
An inner lid 16 whose peripheral edge is placed on the outer peripheral edge of the inner pot so as to cover the upper opening of the inner pot; A heat insulating lid with good heat conduction formed with a flange 17 to be placed on the heat insulating material 1
9 is an internal cover that covers the upper surface of the holding cover 16, and the - side is pivotally supported on the frame 1 to be freely rotatable, and the other side is freely latched to the frame.

Reference numeral 20 denotes a knob protruding upward from the center of the inner lid 14 and fixed thereto, and reference numeral 21 fits and fixes to the lower part of the knob 20, with its outer periphery covering the steam holes 15 and 15 to secure the inner lid 14. An elastic body is brought into close contact with the upper surface, 22 is an elastic fitting body that is fitted and fixed in the center of the heat-insulating lid 16, and 23 is a retaining body that locks the heat-insulating lid 16 and the inner lid 14 provided at the center of the back surface of the outer lid 18. At the same time, it is a pressure locking mechanism for pressing each downwardly, and has a pressing metal fitting 24 that presses the knob 20 and an elastic engagement body 25 that locks the knob 20, and a pressing plate 2 that presses the heat insulation lid 16.
6 and a spring 27.

Reference numeral 28 denotes a steam venting device which is fixed at a proper position on the heat insulating lid 16 and communicated with the outside air through the outer lid 18, and 29 represents the heating plate 12.
a rice-cooking thermostat installed in the center of the heating plate and always energized so as to protrude from the upper surface of the heating plate; 30, a heat-retaining thermostat for controlling the heat-retaining heater 11 mounted on the outer wall of the outer pot 2; 31; is a switch lever which is partially pivoted and movable, and has one end protruding outside the frame 1 and the other end connected to the rice cooking thermostat 29; 32 is a back cover that also serves as a support leg that covers the lower part of the frame 1; be.

Next, talking about the operation, when cooking rice, the inner pot 13
are stored in an outer pot 2 and placed on the bottom heating plate 12, each lid is placed, and one end of a switch lever 31 is pressed down to close a rice cooking thermostat 29 and heat the heating plate 12.

As the heating plate 12 heats up, the bottom surface of the inner pot 13 is heated and cooking progresses, and a part of the hot air rises upward through the gap l and enters the space S between the heat-insulating lid 16 and the inner lid 14. Thermal lid 1
6 and the inner lid 14 to prevent dew from adhering to the inner surface of the inner lid 14, and also heat the inner pot 13 from the outer surface.

Then, the steam in the inner pot 13 flows out from the steam holes 15.15, expands the elastic body 21, enters the space S, and is discharged together with hot air into the outside air via the steam venting device 28.

Eventually, the rice-cooking thermostat 29 detects a sudden rise in temperature inside the inner pot 13 as rice cooking is completed, and pushes down the other end of the switch lever 31 to turn on the heat-retaining circuit (not shown) consisting of the heat-retaining heater 11 and the heating plate 12. Switch.

Immediately after this rice cooking, the inside of the inner pot 13 is at a high temperature, so the thermostat 30 for keeping warm is open, and the heating of the heater 11 for keeping warm is stopped.

Then, when the temperature inside the inner pot 13 gradually decreases to slightly below 70°, the heat retention thermostat 30 is turned on and the heating plate 1 is turned on.
At the same time, the heat-retaining heater 11 is energized to heat the outer pot 2 through the gap 1 and also heat the inner pot 13 from the side surface.

At this time, the heat from the heat retaining heater 11 heats the heat transfer plate 9 via the rising wall 5 of the outer pot 2, heats the heat retaining lid 16 via the flange 17, and also heats the top surface of the inner pot 13. The entire surface can be kept warm, which is an ideal heating method.

On the other hand, the air in the heat storage chamber 10 is heated by the heat generated by the heat retention heater 11.

When the temperature of the inner pot slightly exceeds 70°, the heat-retaining thermostat 30 is turned off and the temperature decreases.
Since the temperature of the air in the heat storage chamber 10 does not drop rapidly, the heat conduction to the heat-insulating lid 16 does not drop sharply, but gradually drops.

Furthermore, the hot air that heats the air in the heat storage chamber 10 also heats the outer pot, so the heat retention thermostat l-30 is turned off.
It softens the sudden temperature drop at times.

Then, when the temperature of the inner pot decreases little by little and drops below 70° again, the heat-retaining thermostat 30 turns OFF as described above.
The heat retention heater 11 generates heat by applying N, but due to the heat in the heat storage chamber 10, the rapid heat is not directly and instantaneously transmitted to the heat retention lid 16 and the outer pot 2, and the heat retention thermostat 30 is set to 0N-. Prevents thermal shock associated with OFF operation.

In the present invention, the heat storage chamber 10 is formed by the outer pot 2 and the heat dissipation plate 9 together with the stepped portion 7 of the frame cover 6, but the upper peripheral edge of the outer pot 2 is further extended upward and curved outward horizontally. The heat storage chamber may be formed between the bent part of the lever and the stepped part of the frame cover, but in this case, heat transfer to the heat-insulating lid and outer pot will be slightly faster than in the case where a heat transfer plate is provided. .

In short, the present invention basically forms a sealed heat storage chamber between the stepped portion of the frame cover and the upper peripheral edge of the outer pot, and provides a heat-retaining heater attached to the outer wall of the outer pot within this heat storage chamber. At the same time, the outer periphery of the heat insulating lid is placed on the heat storage chamber so as to enable heat conduction with the heat storage chamber.

As described above, the present invention forms a heat storage chamber that is sealed around the entire circumference between the stepped portion of the frame cover and the upper peripheral edge of the outer pot, and is attached to the outer wall of the outer pot within the heat storage chamber for heat retention. Since a heat-retaining heater controlled by a thermostat is provided, and the outer periphery of the heat-retaining lid is placed on the heat storage chamber so as to enable heat conduction with the heat storage chamber, ON-OFF control of the heat-retaining thermostat is possible. The temperature rise caused by the heat generated by the heat-retaining heater and the temperature drop caused by the stop of heat generation caused by this are instantaneously and directly transmitted to the outer pot and the heat-retaining lid, and the rice can be kept warm for a long time in a delicious state.

That is, the heat storage chamber suppresses the thermal shock (temperature difference) that occurs when the heat retention heater generates heat and stops generating heat by the heated air in the room, and always transmits substantially stable heat to the outer pot and heat retention lid. Prevents temperature unevenness in cooked rice.

Further, the lower part of the heat storage chamber can be formed by a frame cover, which improves the degree of sealing, prevents the intrusion of foreign substances such as heat insulating material, and greatly simplifies the formation of the heat storage chamber.

Furthermore, the heat storage chamber facilitates the electrical connection of the heat-retaining heater, and by providing it around the entire circumference, the outer pot and the heat-retaining lid are uniformly heated over the entire circumference.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the heat-retaining electric cooker of the present invention, and FIG. 2 is a sectional view of the main parts. 1...Frame, 2...Insulation material, 3.
...Outer pot, 6...Frame cover, 7.
...Stepped portion, 9... Heat sink, 10...
・・Heat storage chamber, 11・・Heater for heat retention, 13・
...Inner pot, 16...Heat insulation lid, 30...
...thermostat for heat retention.

Claims (1)

[Scope of utility model registration request] a frame, an outer pot with good heat conduction attached to the frame with a heat insulating material interposed therebetween, a ring-shaped frame cover having a stepped portion for fixing the upper peripheral edge of each of the outer pot and the frame; The frame cover consists of an inner pot that can be stored freely in the outer pot, a heat-retaining lid with good heat conduction that covers the outer pot, and a heat-retaining heater that is attached to the outer wall of the outer pot and is controlled by a heat-retaining thermostat. A heat storage chamber sealed around the entire circumference between the stepped portion and the upper peripheral edge of the outer pot is formed, and the heat retention heater is provided in the heat storage chamber to enable heat conduction to and from the heat storage chamber. A heat-retaining electric cooker characterized in that the outer periphery of the is placed in a heat storage chamber.