JPS6131823A - Heating cooker - Google Patents

Abstract

PURPOSE:To make favorable the response of a heat-sensitive element part to heat, and to allow suitable cooking, by directly receiving the temperature in a cooking chamber by a heat-sensitive element part thereby controlling a heater. CONSTITUTION:A thermostat 10 is attached via an attachment frame 9 to an upper part of an operation panel section 8 on one side of a main body 1 of an electric oven and is composed of a heat-sensitive element part 12 and a switch section 13 having an interlocking type contact mechanism. The heat-sensitive element part 12 is composed of a material having a high linear expansion coefficient like stainless steel and a material having a low linear expansion coefficient like amber which are integrated, and the difference between their expansions is transmitted to an actuation piece 14 to open or close the switch section 13 to turn on or off a power source to heaters 4, 5. The heat-sensitive element part 12 is extended from a side wall of an inner case 2 slantly toward the heater 4 in an upper part in a cooking chamber 3. In this arrangement, the response to heat becomes very favorable, the starting temperature becomes low, the ripples become small, and stable temperature control becomes possible.

Description

[Detailed description of the invention] [Technical field of invention] The present invention relates to a heating cooker such as an electric oven.

[Technical background of the invention]

Conventionally, electric ovens have an inner case inside the main body to form a cooking chamber, a heater is installed in this cooking chamber, and a bimetallic thermostat is attached to the outside of the inner case to control the heater via a heat transfer plate. , the temperature inside the cooking chamber is detected by a thermostat via the inner case and heat exchanger plate,
The heater is controlled to turn on and off.

[Problems with background technology]

The electric oven as described above has the following problems in terms of temperature control.

Since the barrel is installed outside the cooking chamber, it is not possible to directly sense the temperature inside the cooking chamber.

The bimetal, which is a heat-sensitive element, receives heat indirectly through heat conduction from the heat transfer plate and radiant heat from the cooking chamber to the outside, so the heat reception efficiency is poor (and the amount of heat received tends to fluctuate).

Therefore, as shown in FIG. 5A, the rising temperature in the cooking chamber becomes abnormally high, the on/off ripples become large, and the ripples become irregular.

In addition, the form of heat transfer tends to change depending on the volume and structure of the cooking chamber, the material of the inner case, etc., and for proper temperature control, the size and number of holes in the ventilation holes on the back plate of the main unit must be changed. Therefore, it is necessary to take measures such as adjusting the environmental temperature of the part where the thermostat is installed.

Since temperature control is difficult, cooking may fail or results may vary, making it difficult to always achieve good cooking results.

Furthermore, in recent years, revisions have been made to radio noise regulations, but in the case of slow-acting thermostats, the noise generated when the contacts turn on and off tends to become continuous noise.
Regulatory values cannot be met. To deal with this, it is necessary to construct an interlocking type switch with less noise, but in the current state of poor thermal response, the on/off ripple will further increase. For example, the ripple of a slow-acting thermostat alone is usually around 3 deg, but the ripple of an interlocking thermostat is 3 to 5 times that of 10 deg. The ripple is enlarged and the slow motion type is 5
0-80 deo, 120-200 for quick-acting type
deg, which is impossible for practical use.

[Purpose of the invention]

The present invention aims to solve the above-mentioned problems, and improves the heat receiving efficiency of the heat-sensitive element of the thermostat, improves thermal response, enables proper cooking, and complies with radio noise regulations. The purpose of this invention is to provide a heating cooker that can be used even if the

[Summary of the invention]

The heating cooker of the present invention has a cooking chamber formed in the main body, a heater provided in the cooking chamber, and a thermostat for controlling the heater. The heat-sensitive element part of the metal expansion type thermostat, which consists of a formed cylindrical heat-sensitive element part and a switch part having an interlocking contact mechanism operated by the heat-sensitive element part, is installed so as to protrude into the cooking chamber. The feature is that the temperature inside the cooking chamber is directly received by the heat-sensitive element to control the heater.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows an electric oven, in which an inner case 2 is housed within a main body 1, and a cooking chamber 3 is formed within the inner case 2. Further, a door 6 that covers the front opening of the cooking chamber 3 is attached to the front surface of the main body 1 so as to be openable and closable, and a back plate 7 is attached to the back surface of the main body 1.

A thermostat 10 is attached to the upper part of the operation panel section 8 on one side of the main body 7 via a mounting frame 9, and a temperature control knob 11 of the thermostat 1o is removed.

The thermostat 10 is a metal expansion type interlocking type, and as shown in FIGS. 2 and 3, it includes a cylindrical heat-sensitive element portion 12 integrally formed of metals having different coefficients of linear expansion; The switch part 13 is provided at the base of the heat-sensitive element part 12 and has an interlocking contact mechanism operated by the heat-sensitive element 1 part 12. The heat-sensitive element part 12 is made of, for example, stainless steel having a large linear expansion coefficient. The pipe is integrally formed with a material such as amber having a small coefficient of linear expansion, and the difference in expansion between the two is absorbed by the actuating piece 14.
to open and close the switch section 13, and the heaters 4 and 5
and the heat sensitive element part 1 of the thermostat 10
2 protrudes from the side wall of the inner case 2 at an upper part of one side in the cooking chamber 3 at a slight inclination toward the heater 4 .

By doing this, the heat-sensitive element section 12 directly contacts the heated air in the cooking chamber 3 and receives heat, resulting in extremely good thermal response, and even though the switch section 13 is an interlocking type, the As shown in Figure B, the rising temperature and ripples are small, and stable temperature control is possible. Furthermore, since the thermostat 10 is not affected by the environmental temperature, even if the volume and structure of the cooking chamber 3, the material of the inner case 2, etc. differ, the size and position of the ventilation hole formed in the back plate 7, There is no need to worry about the number of holes etc.
Design becomes easier.

In addition, in FIG. 4, a convex portion 15 is formed outward on the wall of the inner case 2 at a portion through which the heat-sensitive element portion 12 is inserted, thereby increasing the heat receiving area of the heat-sensitive element portion 12 and further improving thermal responsiveness. It has been improved. In addition, on the contrary, the heat-receiving area of the heat-sensitive element part 12 can be adjusted by forming the convex part 15 inward. The heat receiving area can also be adjusted by changing the protruding length of the portion 12.

In this way, the thermal response can be changed depending on the size of the heat-receiving area of the heat-sensitive element portion 12, and the ripple in the cooking chamber 3 can be arbitrarily adjusted. According to experiments, the relationship between the protrusion length of the heat-sensitive element portion 12 into the cooking chamber 3 and the on/off ripple is as follows.

Ripple (deg)20
70-90 40 50-60 60 30-40 The heat-sensitive element 12 of the thermostat 10 may protrude into the cooking chamber 3 at any position, such as above, below, outside, on the right, or at the rear. It is effective if it is installed near the heaters 4 and 5 so that it does not get in the way of objects, grills, receiving surfaces, etc., and does not interfere with the attachment and detachment of the heaters 4.5. By making the portion 12 project in an inclined manner, it can be further unobstructed.

〔Effect of the invention〕

According to the present invention, the heat-receiving efficiency of the heat-sensitive element of the thermostat is improved to improve thermal response, and proper cooking is possible, thereby preventing cooking failures or variations in finished product, and ensuring good cooking. can be obtained, and
The interlocking switch section allows it to comply with radio noise regulations.

[Brief explanation of drawings]

Fig. 1 is a partially cutaway perspective view showing an embodiment of the heating cooker of the present invention, Fig. 2 is a perspective view of the thermostat shown in Fig. 1, and Fig. 3 is a plan view of the thermostat shown in Fig. 2; FIG. 4 is a side view of a part of another embodiment, and FIG. 5 is a diagram showing the operating characteristics of the thermostat. 1. Main body, 3. Cooking chamber, 4, 5.. Heater, 10.
Mostat, 12...Thermal element part, 13...
Switch part, 15... Convex part.

Claims (4)

[Claims] (1) In a heating cooker that has a cooking chamber in the main body, a heater in the cooking chamber, and a thermostat to control the heater, a cylindrical tube integrally formed of metals with different coefficients of linear expansion is used. A heating cooking characterized in that the heat-sensitive element part of a metal expansion type thermostat comprising a heat-sensitive element part and a switch part having an interlocking contact mechanism operated by the heat-sensitive element part is installed so as to protrude into the cooking chamber. vessel. (2) The cooking device according to claim 1, wherein the heat-sensitive element of the thermostat is disposed near the heater in the cooking chamber. (3) The cooking device according to claim 1 or 2, characterized in that the heat-sensitive element portion of the thermostat is provided in an inclined manner. (4) The inner wall of the cooking chamber in the portion through which the heat-sensitive element portion of the thermostat is inserted is a convex portion on either the inner or outer side. heating cooker.