JPS5940821A - Heat retention equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a heat-retaining appliance such as a jar rice cooker.

Conventional configuration and problems Conventional heat retention appliances, for example, jar rice cookers, are kept warm by using a heat retention heater wrapped around the outside surface of the inner frame, a rice cooking heater attached to the bottom of the inner frame, and a rice cooker attached to the inside of the outer lid. This was done by generating heat with a lid heater and maintaining the cooked rice inside the pot at a constant temperature of around 70°C.

The heat-retaining heater mainly uses a cord heater coated with silicone rubber, and the heater is wrapped and attached to the outer surface of the inner frame in various ways.

As an attachment method, there is a method in which silicone rubber-coated heaters are wrapped around the outer surface of the inner frame in multiple layers and fixed with an adhesive. Another method of attachment involves arranging silicone rubber-coated heaters in a zigzag pattern on a thin piece of aluminum, gluing them together, and wrapping the heaters around the outer surface of the inner frame.

According to the above method, the length of the silicone rubber-coated heater is set to several times the outer circumference of the inner frame.
The constant operating temperature is around 120'C, and the temperature of cooked rice is 70'C.
On the other hand, the temperature difference is small, and therefore there is a problem of poor thermal efficiency. Also, when keeping the pot warm, dew tends to accumulate on the top of the pot, but because the temperature of the heater is low,
It has little effect on evaporating the dew that adheres to the top of the pot.
The amount of dew on the top of the pot increases over time. For this reason, there was a drawback that the cooked rice adhering to the inside of the pot absorbed dew and turned white.

On the other hand, the area in which the silicone rubber-coated heat-retaining heater is wrapped becomes large, which poses design difficulties when selecting the mounting position of the temperature-sensitive switch. In addition, the workability was poor and automation was difficult.

OBJECTS OF THE INVENTION The present invention has been made in view of the above-mentioned drawbacks of the conventional technology.It is an object of the present invention to provide a heat-retaining device that improves the thermal efficiency of a heat-retaining heater, significantly reduces costs, and enables good heat retention of objects to be kept warm. That is.

Structure of the Invention The present invention uses a glass braid coated heater as a heat retention heater,
Only one turn of this cord heater is wrapped around the outer surface of the inner frame to generate heat at a high temperature.

Description of examples Embodiments of the present invention will be described below with reference to FIGS. 1 to 3.

The figure shows a jar rice cooker, and in Fig. 1, 1 is a cylindrical outer frame, 2 is a cylindrical inner frame formed by drawing a thin metal plate, and 3 is an inner frame of the inner frame 2. A rice cooking heater equipped at the bottom, 4 a pot removably placed on the rice cooking heater 3, 5 an outer lid with an insulated structure, and 6 an inner lid that covers the upper opening of the pot 4 outside the inner frame 2. A caulking metal fitting 9 fixed to the side surface is a glass braided-coated cord-like heat insulating heater that is wrapped around the outer surface of the inner frame 2 and attached by caulking with the caulking metal fitting 8, and as shown in FIG. Both ends are swaged separately so that they overlap somewhat. 10 is a caulking rivet, 11 is a temperature-sensitive switch mounting base fixed to the outer surface of the inner frame 2 by a caulking rivet 10, 12 is a temperature-sensitive switch screwed to the base 11, and 13 is a rice-cooking operation. The start switch 14 is a magnetic thermostat that detects the temperature at the bottom of the pot and completes the rice cooking operation.

The rice cooking and warming operations according to this configuration will be explained with reference to FIG. 2.

When the rice cooking start switch-13 is operated, the rice cooking heater 3
is energized and begins to generate heat. The rice placed in the pot 4 is heated by the rice cooking heater 3, and cooking is started. In the later stages of rice cooking, the magnetic thermostat 14 is activated by detecting the temperature at the bottom of the pot, and the rice cooking is completed by operating the switch 13.

At this time, a heat-retaining circuit is formed by the heat-retaining heater 9, the lid heater 7, and the rice cooking heater 3, and heat-retaining is started. Immediately after rice cooking is completed, the temperature of the cooked rice in the pot is close to 100'C, so the temperature-sensitive switch 12 is turned off. Thereafter, when the temperature of the cooked rice in the pot gradually decreases to around 70'C, the temperature-sensitive switch 12 is turned on and electricity starts to be supplied to the heat-retaining circuit. After that, the temperature-sensitive switch 12 is turned ON and OFF.
Repeat this process to maintain the temperature of the cooked rice in the pot at a constant temperature of around 70'C.

According to this embodiment, since the glass braid coated cord-shaped heat insulating heater is provided with only a single winding, the operating temperature while energized is about 180'C, and the temperature difference is small compared to the temperature of cooked rice, which is 70'C. It is large and has better thermal efficiency than silicone rubber coated heaters. Furthermore, when keeping warm, the dew that adheres to the top of the pot is heated at a high temperature to turn it into steam again, which prevents the surface of the cooked rice from drying out and prevents the cooked rice around the inside of the pot from absorbing water.

On the other hand, the area in which the heat-retaining heater is wrapped only needs to be small, making it easy to select the mounting position of the temperature-sensitive switch. In addition, work efficiency and time per work are improved, and automation becomes easy.

Effects of the Invention According to the present invention, by wrapping a glass braid-coated cord-shaped heat-insulating heater around the outer surface of the inner frame, thermal efficiency during heat-keeping is improved, and the heat-retaining state is not only improved, but also design is simplified. It is possible to achieve significant cost reductions by making automation possible.

[Brief explanation of the drawing]

FIG. 1 is a cutaway sectional view of a main part of a jar rice cooker showing an embodiment of the present invention, FIG. 2 is a circuit diagram, and FIG. 3 is a perspective view of an inner frame portion. 1...Outer frame, 2...Inner frame, 5...
... Lid (outer lid), 9... Warmth retention heater. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 5 Figure 3

Claims (1)

[Claims] A main body with an inner frame inside an outer frame, a pot housed in the main body, a lid covering an opening on the top surface of the main body, and a glass braided coated cord-shaped heat insulating heater wrapped one turn around the outer surface of the inner frame. Equipped with thermal equipment.