JPS6337650B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rice cooker that suppresses the rise in temperature around the outside during the rice cooking process and improves the quality of rice.

Traditionally, gas-type rice cookers have been the mainstream for commercial use, and when cooking rice with a gas rice cooker, the area around the outer case becomes extremely hot and cannot be touched by human hands. It was about right. Also,
An electric rice cooker has two methods: a pot is removably placed directly on top of a hot plate with an electric heater, and the heat from the electric heater is conducted from the hot plate to the bottom of the pot to cook rice; A method in which a heating space is provided, a heater is placed in this space at a predetermined distance from the pot, and rice is cooked by heating the pot using radiant heat from the heater and convection of air within the space. There is. In the former method, the temperature difference between the top and bottom of the rice tends to increase during the rice cooking process, and the top part is undercooked and becomes dry and dry, while the bottom part is overcooked and becomes sticky. The rice was cooked in a dry state, resulting in uneven cooking and the overall taste was poor. Moreover, this tendency becomes stronger as a large amount of rice is cooked using a large commercial rice cooker. The latter method has the advantage of being able to heat the food from the outside of the side of the pot, making it easier to achieve relatively uniform cooking, but the heat efficiency is lower than the former method, so it is necessary to increase the heater power. Since heat loss increases the temperature of the vessel, heat shielding measures are required on the inside of the vessel. When cooking large amounts of rice for commercial purposes, heat shielding measures tend to become even more stringent. In addition, immediately after the thermo switch activates when rice cooking is completed and the power to the heater is stopped, the heater reaches a high temperature, and the parts that support the heater, such as the heater stand, also become high temperature, and the overall heat capacity is maintained high. This heat also causes the rice on the bottom of the pot to burn. This tendency is observed when the heating space has a closed structure, resulting in strong scorching.

The present invention has been made in view of the above circumstances, and includes a pot that is housed in an inner case with a heating space around the outside of the pot, and an electric heater placed in the space at a predetermined distance from the pot. By providing a predetermined distance between the side surface of the pot and the side surface of the inner case and between the top end of the pot and the top end of the inner case, rice can be cooked evenly. The purpose of this invention is to provide a rice cooker that can significantly improve the taste of cooked rice, suppress the rise in temperature at the bottom of the pot, and is suitable for commercial use with less charring. .

Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings.

In FIG. 1, reference numeral 1 denotes a cylindrical outer case, and metal fittings 2 are fixed to the upper inner surface of the case at two opposing locations. Reference numeral 3 designates an inner case, which has a flange portion 3a protruding toward the outer circumference at the upper end opening of the inner case 3, and a metal fitting located below the flange portion 3a on the outer circumference side of the inner case 3. 4 are fixed to the upper inner peripheral side of the flange portion 3a at four locations at approximately equal intervals at the same time as the spacers 5 are fastened. The upper part of the metal fitting 4 is locked to the upper end of the outer case 1, and the lower part is fastened to the metal fitting 2 at two opposing locations with screws. Further, the spacer 5 is slightly convex upward from the upper end of the flange portion 3a of the inner case 3, and the fastening portion is molded from a plastic material into a concave shape so that the head of the fastening part does not protrude. , four are arranged at approximately equal intervals. Further, the inner case 3 is installed in the outer case 1 with a space formed between the flange portion 3a and the upper end of the outer case 1. 6 is a pot having a flange portion 6a projecting upward and outward at the upper end opening;
This pot 6 has a spacer 5 at the lower end of the flange portion 6a.
It is placed in the inner case 3 and stored in a suspended state in a detachable manner. As a result, a continuous heating space is formed from the outer periphery of the side surface of the pot 6 to the lower part of the bottom. 7 is a lid having a knob 8;
is placed on the flange portion of the pot 6 and closes the inside of the pot 6. Reference numeral 10 denotes a bottom plate having support legs 9, and this bottom plate 10 is fitted and fixed to the lower end of the outer case 1. Further, substantially annular ribs 11a and 11b that are convex toward the inner surface are formed on the bottom of the inner case 3, and a ventilation hole 12 is formed on the inner peripheral side of the rib 11a.

A reflector 13 is placed on the upper surface of the ribs 11a, 11b to reflect the heat of the heater toward the pan 6, and this reflector 13 is fixed to the bottom of the inner case 3 at the same time as the heater support 14 is fixed. There is. The outer circumferential side of this reflector 13 extends upward in a substantially arc shape, and its outer circumferential diameter forms a minute gap with the inner diameter of the inner case 3. The inner circumferential side is formed into a convex shape, and the convex portion A ventilation hole 15 is formed on the top surface. The heater support stand 14 is formed into an L shape, and has 4 holes at the upper end.
It has cutout portions 16 at several places, and this cutout portion 16 has three
Book sheathed heaters 17, 18, 19 are placed, and these sheathed heaters 17, 18, 19
Heater holding bracket 20 to prevent it from coming off upwards.
21 is fixed. Also, the heater support stand 14
is fixed by molding one of the mounting parts into a crank shape, inserting it into a hole provided on the upper surface of the rib 11a located at the bottom of the inner case 3, and fixing the other part to the rib 11a.
It is fixed by being fixed to the pot hole on the upper surface of 1b with screws via the reflector 13. The bottom of the pot 6 has a substantially spherical cross section with a convex inner surface, and the distance between the three sheathed heaters 17, 18, 19 and the bottom of the pot 6 is
The sheathed heater 17 is located higher than the other two sheathed heaters 18 and 19 with respect to the cross-sectional shape of the bottom.

In addition, a heat-sensitive device 22 is installed in the center of the outer bottom of the pot 6 to detect the pot temperature and control rice cooking. 23, a heat shield ring 24, and a heat shield cylinder 25 are provided. The heat shielding ring 24 is formed from a plate of aluminum material into a cylindrical shape with a substantially U-shaped cross section.
and the heat-sensitive device sliding plate 26, so that it is fitted between them. In addition, the heat-sensitive device sliding plate 2
6 has three claws 27 at approximately equal intervals on the lower side, and these claws 27 can be bent by inserting them into claw through holes formed in a heat-sensitive device fixing plate 28 fixed to the center of the bottom of the inner case 3. It is locked by. On the other hand, a claw 22a also protrudes downward from the bottom of the heat-sensitive device 22, and this claw 22a is attached to the heat-sensitive device sliding plate 2.
It is locked by inserting it into a claw through hole formed in 6 and bending it.

29 is a coil spring that always urges the heat sensitive device 22 upward; 30 is a coil spring that always pushes the heat shield ring 24, the heat sensitive device outer case 23, and the heat sensitive device sliding plate 26 upward; The spring force is increased compared to . 31
is a rice cooking lever that transmits the rice cooking control operation of the heat sensitive device 22 to the micro switch 32, and this rice cooking lever 31 is rotatably mounted on a bearing 35 of a frame 34 attached to an operation plate 33 fixed to the outer case 1. It is being 36 is a rice cooking lever knob for starting rice cooking.

Next, the operation of this embodiment configured as above will be explained. Washed rice and water necessary for cooking the rice are stored in the pot 6, and the flange part 6
A is placed on the spacer 5 fixed to the flange portion 3a of the inner case 3, the pot 6 is housed in the inner case 3, and the outer lid 7 is closed. Next, when the rice cooking lever 31 is rotated in the direction of arrow a by pressing down the rice cooking lever knob 36 and the heat sensitive device 22 is brought into contact with the center of the outer bottom surface of the pot 6, the micro switch 32
is closed, and as a result, the sheathed heater 19 is energized, and the rice in the pot 6 starts absorbing water by the heat of this sheathed heater 19. During water absorption, only the sheathed heater 19 is energized, so that the sides of the pot 6 are heated intensively. Then, approximately 15 minutes after the start of energization to the sheathed heater 19, energization of the sheathed heaters 17 and 18 is started by a control circuit (not shown). When energization of the sheathed heaters 17 and 18 is started,
At the same time as the sheathed heater 19 is energized, the process moves to the main rice cooking process. As the rice cooking progresses further and the water in the pot 6 decreases due to water absorption and evaporation of the rice, the temperature at the bottom of the pot 6 rapidly increases, and the adsorption power of the heat-sensitive device 22 rapidly decreases. As a result, the rice cooking lever 31 is rotated back in the direction opposite to the direction of the arrow a, so that the micro switch 32 is opened and the rice cooking is completed.

During the rice cooking process, air convection occurs through the gap between the outer case 1 and the inner case 3.
In addition, since cold air flows in through the gap in the bottom plate 10, the temperature outside the outer case 1 is much lower than that of the inner case. In addition, by providing a space between the inner surface of the inner case 3 and the outer surface of the pot 6, heating convection occurs, so heating from the sides and bottom of the pot 6 cooks very delicious rice with less uneven cooking. In addition, since the temperature rise at the bottom of the pot 6 during steaming can be controlled, there is little chance of burning, making the rice cooker suitable for commercial use.

As described above, according to this embodiment, a space is formed between the entire circumference of the flange portion 6a formed at the upper end of the pot 6 and the upper surface of the flange portion 3a of the inner case 3,
Furthermore, since a space is formed between the entire circumference of the flange portion 3a formed at the upper end of the inner case 3 and the upper end of the outer case 1, the space between the outer case 1 and the inner case 3 is insulated. It is possible to suppress the temperature rise of the outer case 1 during rice cooking without intervening a heat shield such as wood, and by uniformly heating the pot 6 from the sides and bottom, the rice can be cooked evenly. It becomes possible to eliminate unevenness and prevent the progression of scorching on the bottom surface.

Furthermore, since the temperature rise of the outer case 1 can be suppressed, the materials of the switch 33 and the handle (not shown) can be made of medium-temperature materials instead of high-temperature plastic materials (for example, phenolic resin). (polypropylene, nylon, etc.), and also has an advantage in terms of cost for the parts that come into contact with the outer case 1.

Furthermore, since a plurality of spacers 5 are fixed to the inner case 3, a predetermined distance is maintained between the side surface of the pot 6 and the side surface of the inner case 3, and this space promotes convection of heated air. By heating the side surface of the pot 6 and simultaneously attaching a plurality of spacers 5 to the inner case 3, the pot 6 is housed in the center of the inner case 3, and as a result, heated air is heated. Since the convection flows evenly around the entire outer periphery of the pot 6, the sides of the pot 6 are heated uniformly. In addition, since the spacer 5 is designed to provide a predetermined distance between the flange portion 3a of the inner case 3 and the flange portion 6a of the pot 6, it promotes the aforementioned convection of heated air and also When the sheathed heaters 17, 18, 19 and the reflector 13 are kept at a high temperature, the bottom of the pot 6 is exposed to high temperatures and accelerates the progress of scorching, but the spacer 5 prevents the rice from being cooked. Even after the heating is completed, the convection of the heated air continues, and the parts that are kept at a high temperature, such as the bottom of the pot 6, the sheathed heaters 17, 18, 19, and the reflector 13, are transferred from the air holes (not shown) in the bottom plate 10 to the air holes 12. , 15 by the convection of outside air, it is possible to suppress the rise in temperature of the bottom surface of the pot 6, thereby suppressing the progress of scorching. Furthermore, in this embodiment, heat-resistant plastic is used for the spacer 5, but since the pot 6 is configured to come into contact only with the spacer 5 unless it is blocked by the outer lid 7, the pot 6 may be damaged. It is possible to prevent this from occurring, and when the spacer 5 is mainly worn and parts need to be replaced, it is only necessary to replace the spacer 5 as necessary, making parts replacement inexpensive and easy. Furthermore, since the spacer 5 is made of a material with poor thermal conductivity, it suppresses the rise in temperature of the inner case 3, and also has a positive effect on the temperature of the outer case 1, which maintains a constant distance from the inner case 3. This also serves to suppress the temperature rise of the outer case 1.

As is clear from the description of the above embodiments, according to the present invention, it is possible to significantly suppress the temperature rise of the outer case during rice cooking, and the pot can be heated from the sides and bottom, thereby preventing uneven cooking. It is possible to provide a rice cooker that does not burn the rice and causes less burning.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a rice cooker showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the main part, and FIG. 3 is a perspective view of the main part. 1... Outer case, 3... Inner case, 3a... Flange part, 6... Pan, 6a... Flange part, 7...
... Lid, 10 ... Bottom plate, 17, 18, 19 ... Sheathed heater, 22 ... Heat sensitive device, 32 ... Micro switch.

Claims (1)

[Claims] 1. an outer case, an inner case having an outwardly oriented flange at its upper end, and installed within the outer case with a space formed between the flange and the upper end of the outer case; It has a flange portion directed upward and outward at the upper end, and a space is formed between the flange portion and the upper end portion of the inner case, and is removably housed within the inner case and is connected to the inner surface of the inner case. a pot forming a predetermined space between them; an electric heater provided at a predetermined interval within the space formed between the pot and the inner surface of the inner case; A rice cooker comprising: a heat-sensitive device positioned and in close contact with the pot; and a switch that shuts off the power when the temperature sensed by the heat-sensitive device reaches a predetermined temperature.