Heating Regulator

Abstract

A cooking appliance comprising a heating chamber 1, a lower chamber 2 located below the bottom wall portion 11 of the heating chamber 1, and a gas burner 3 positioned inserted into a burner mounting hole 15 formed in the bottom wall portion 11 so as to extend from the heating chamber 1 to the lower chamber 2, which heats the food to be cooked with the food placed on the bottom wall portion 11, is designed to suppress the cooling of the bottom wall portion 11 by secondary air flowing into the burner mounting hole 15, thereby shortening the preheating time. [Solution] A burner enclosure member 7 is installed in the burner installation hole 15, surrounding the gas burner 3 with a gap for secondary air to flow around it, such that there is a gap between the peripheral wall surface of the burner installation hole 15 and the burner enclosure member 7. A member 72 is provided between the peripheral wall surface of the burner installation hole 15 and the burner enclosure member 7 to prevent communication between the heating chamber 1 and the lower chamber 2 through the gap.

Description

Technical Field

[0001] The present invention relates to a cooking appliance including a heating chamber for storing a cooking object and having an entrance and exit for the cooking object, a lower chamber located below the bottom wall portion of the heating chamber, and a gas burner, and heating the cooking object by combustion of the gas burner with the cooking object placed on the bottom wall portion.

Background Art

[0002] Conventionally, as this type of cooking appliance, a burner installation hole is formed in the bottom wall portion of the heating chamber so as to reach from the heating chamber to the lower chamber, and a gas burner having an upward combustion plate portion for ejecting gas is arranged in a state of being inserted into the burner installation hole (see, for example, Patent Document 1).

[0003] In this case, since the secondary air necessary for combustion of the gas burner flows from the lower chamber through the burner installation hole, the peripheral wall surface of the burner installation hole is cooled by the secondary air. Therefore, the temperature of the bottom wall portion of the heating chamber (particularly, the portion of the bottom wall portion near the burner installation hole) is difficult to rise due to heat draw from the burner installation hole. As a result, the preheating time required to raise the temperature of the bottom wall portion of the heating chamber to the temperature required for cooking becomes long, and the running cost increases.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In view of the above points, an object of the present invention is to provide a cooking appliance capable of shortening the preheating time and reducing the running cost.

Means for Solving the Problems

[0006] To solve the above problems, the present invention provides a cooking appliance comprising a heating chamber having an entrance and exit for the food to be cooked, a lower chamber located below the bottom wall of the heating chamber, and a gas burner having an upward-facing combustion plate portion for ejecting gas, which is inserted into a burner installation hole formed in the bottom wall so as to reach from the heating chamber to the lower chamber, wherein the food to be cooked is placed on the bottom wall and heated by the combustion of the gas burner, wherein a burner enclosure member is installed in the burner installation hole, surrounding the gas burner with a gap for secondary air to flow around it, such that there is a gap between the peripheral wall surface of the burner installation hole and the burner enclosure member, and a communication obstructing member is provided to prevent communication between the heating chamber and the lower chamber through this gap.

[0007] According to the present invention, the secondary air necessary for the combustion of the gas burner flows through the gap between the gas burner and the burner enclosure member, and the flow of secondary air into the gap between the peripheral wall surface of the burner installation hole and the burner enclosure member is suppressed by the communication inhibiting member. Therefore, cooling of the peripheral wall surface of the burner installation hole by secondary air is suppressed, and the temperature of the bottom wall portion of the heating chamber (especially the portion of the bottom wall near the burner installation hole) rises more easily than in the conventional example. As a result, the preheating time can be shortened and running costs can be reduced.

[0008] Here, it is desirable that the communication-blocking member be made of an insulating material that suppresses heat conduction between the peripheral wall surface of the burner installation hole and the burner enclosure member. This way, even if the temperature of the bottom wall of the heating chamber rises, the temperature rise of the burner enclosure member due to heat transfer through the communication-blocking member is suppressed, and the durability of the burner enclosure member can be improved.

[0009] Furthermore, in the present invention, it is desirable that the gas burner is positioned such that the upper surface of the combustion plate is located below the upper surface of the bottom wall of the heating chamber. This allows the combustion flame generated on the combustion plate to approach the upper surface of the bottom wall, promoting heating of the bottom wall and further shortening the preheating time.

[0010] In this case, it is desirable that the upper end of the burner enclosure member be positioned above the upper surface of the combustion plate and below the upper surface of the bottom wall of the heating chamber. This prevents the secondary air flowing into the burner enclosure member from coming into contact with the peripheral wall surface of the burner installation hole, while bringing the combustion flame generated at a height above the upper end of the burner enclosure member closer to the upper surface of the bottom wall, thereby further shortening the preheating time.

[0011] Furthermore, in the present invention, it is desirable to provide a guide member in the heating chamber that directs the combustion gas generated by the combustion of gas ejected from the combustion plate to a predetermined portion of the upper surface of the bottom wall of the heating chamber. This allows the temperature of the predetermined portion of the upper surface of the bottom wall to rise more quickly. As a result, by making the predetermined portion the area where the food to be cooked is placed, the preheating time can be shortened as much as possible.

[0012] Furthermore, in the present invention, it is desirable that the gas burner be a type of burner that diffuses hydrogen gas during combustion. With this, the water vapor, which is the combustion gas produced by the combustion of hydrogen gas, comes into contact with the food being cooked, making it possible to cook the food to a fluffy finish. However, since diffuse combustion type burners require a lot of secondary air, the bottom wall of the heating chamber tends to heat up slowly, which can lead to longer preheating times. However, in the present invention, as described above, the preheating time can be shortened, so no problems occur. [Brief explanation of the drawing]

[0013] [Figure 1] A perspective view of a heating appliance according to an embodiment of the present invention. [Figure 2] Side view of the heating appliance according to the embodiment. [Figure 3] A cross-sectional plan view obtained by cutting along line III-III in Figure 2. [Figure 4] Enlarged cross-sectional view taken along line IV-IV in Figure 3. [Figure 5] A cross-sectional side view obtained by cutting along the VV line in Figure 4. [Figure 6] A perspective view of the main part of a heating appliance from another embodiment, with a portion removed. [Modes for carrying out the invention]

[0014] The heating appliance of the embodiment of the present invention shown in Figures 1 to 3 comprises a heating chamber 1 for storing food to be cooked, a lower chamber 2 located below the bottom wall portion 11 of the heating chamber 1, and a gas burner 3 for heating the inside of the heating chamber 1, and consists of a so-called pizza oven that heats food to be cooked placed on the bottom wall portion 11 of the heating chamber 1 by combustion of the gas burner 3.

[0015] An opening 13 for food to be cooked is provided on the front side in the depth direction of the dome-shaped chamber wall 12 that covers the heating chamber 1 from above and around. An exhaust pipe 14 communicating with the heating chamber 1 is provided so as to protrude above the chamber wall 12. A control box 22 is provided on the outer surface of one side in the lateral direction of the peripheral wall portion 21 of the lower chamber 2. The control box 22 houses a controller 4 (see Figure 4), which is a control means. A power switch 221 and an ignition switch 222 are also located on the outer surface of the control box 22.

[0016] Referring to Figures 4 and 5, a burner installation hole 15 is formed in the bottom wall 11 of the heating chamber 1, located at the back away from the entrance 13, and extending from the heating chamber 1 to the lower chamber 2. The gas burner 3 is then positioned with the burner installation hole 15 inserted.

[0017] The gas burner 3 comprises an upper burner body 31 with an upward-facing combustion plate section 311 from which gas is ejected, which has numerous flame holes 311a formed therein; a lower burner body 33 positioned below the upper burner body 31 and defining a gas chamber 32 between itself and the upper burner body 31 that guides gas to the combustion plate section 311; and a sealing member 34 consisting of a packing interposed between the upper burner body 31 and the lower burner body 33 around the gas chamber 32. This gas burner 3 is a burner that uses a diffusion combustion method for hydrogen gas. Since hydrogen gas burns quickly and is prone to flashback, a flashback prevention plate 35 with multiple small holes having a diameter less than or equal to the flame extinguishing distance is attached to the gas chamber 32. Furthermore, when hydrogen gas is burned, the combustion gas, which is water vapor, comes into contact with the food being cooked, making it possible to cook the food to a fluffy finish.

[0018] The gas burner 3 is provided with an ignition electrode 36 for igniting the gas ejected from the combustion plate portion 311 and a flame detection element 37 composed of a thermocouple for detecting the combustion flame generated by the combustion of the gas ejected from the combustion plate portion 311. Further, in the gas supply passage 5 for supplying hydrogen gas to the gas burner 3, a main valve 51, an orifice 52 in series with the main valve 51, and a heating power switching valve 53 in parallel with the orifice 52 are interposed. The main valve 51 and the heating power switching valve 53 are constituted by electromagnetic valves controlled by the controller 4. These main valve 51, orifice 52, and heating power switching valve 53 are arranged in the lower chamber 2.

[0019] The cooking heater further includes ultraviolet detection means 6 for detecting ultraviolet rays emitted from the combustion flame generated by the combustion of the gas ejected from the combustion plate portion 311. Here, even if the gas burner 3 misfires, it takes time for the flame detection element 37 composed of a thermocouple to detect the misfire. Therefore, although lacking in reliability, ultraviolet detection means 6 with excellent responsiveness for flame detection is provided so that the misfire of the gas burner 3 can be detected with good responsiveness. Incidentally, the flame detection element 37 is mainly used for ignition confirmation.

[0020] Referring to FIG. 3, the gas burner 3 is arranged such that the combustion plate portion 311 faces the inner part of the heating chamber 1 away from the entrance / exit 13. On the other hand, the ultraviolet detection means 6 is arranged so as to direct the combustion plate portion 311 of the gas burner 3 to a portion of the chamber wall 12 of the heating chamber 1 closer to the entrance / exit 13 than the arrangement position of the gas burner 3. Therefore, the ultraviolet detection means 6 is less likely to be affected by external light entering the heating chamber 1 from the entrance / exit 13, which helps to prevent false detection. In this embodiment, the formation location of the burner installation hole 15, that is, the arrangement location of the gas burner 3, is shifted laterally from the position on the center line of the entrance / exit 13 so that external light does not hit the arrangement location of the gas burner 3 as much as possible. Incidentally, the ultraviolet detection means 6 is well-known, and its detailed description is omitted.

[0021] Incidentally, secondary air is supplied to the gas burner 3 through the burner installation hole 15. When the secondary air touches the peripheral wall surface of the burner installation hole 15 as in the above conventional example, this peripheral wall surface is cooled by the secondary air. Therefore, the temperature of the bottom wall portion 11 of the heating chamber 1 (particularly, the portion of the bottom wall portion 11 near the burner installation hole 15) is difficult to rise due to heat dissipation from the burner installation hole 15. As a result, the preheating time required to raise the temperature of the bottom wall portion 11 of the heating chamber 1 to the temperature required for cooking becomes longer, and the running cost increases. In particular, when the gas burner 3 is a diffusion combustion type, since a large amount of secondary air flows, the above phenomenon becomes remarkable.

[0022] Therefore, in the present embodiment, as shown in FIGS. 4 and 5, a burner enclosure member 7 is provided that surrounds the periphery of the gas burner 3 with a gap through which secondary air flows. The gas burner 3 is supported by the burner enclosure member 7 via a bracket 71 attached inside the burner enclosure member 7. Then, the burner enclosure member 7 is installed in the burner installation hole 15 so that there is a gap between the peripheral wall surface of the burner installation hole 15 and the burner enclosure member 7. Further, a communication inhibiting member 72 is provided to inhibit the communication between the heating chamber 1 and the lower chamber 2 through the gap between the burner installation hole 15 and the burner enclosure member 7. In the present embodiment, the communication inhibiting member 72 is composed of a plate material attached to the lower surface of the bottom wall portion 11 and closing the gap between the burner installation hole 15 and the burner enclosure member 7. Further, the plate material constituting the communication inhibiting member 72 is formed of a ceramic such as ceramic wool or a heat insulating material such as stainless steel that suppresses heat conduction between the peripheral wall surface of the burner installation hole 15, that is, between the bottom wall portion 11 and the burner enclosure member 7. Incidentally, the burner enclosure member 7 may be formed of a stainless steel material having excellent durability and suppressing heat conduction.

[0023] According to this design, the secondary air necessary for the combustion of the gas burner 3 flows through the gap between the gas burner 3 and the burner enclosure member 7, and the flow of secondary air into the gap between the peripheral wall surface of the burner installation hole 15 and the burner enclosure member 7 is suppressed by the communication obstructing member 72. Therefore, cooling of the peripheral wall surface of the burner installation hole 15 by secondary air is suppressed, and the temperature of the bottom wall portion 11 of the heating chamber 1 (especially the portion of the bottom wall portion 11 near the burner installation hole 15) rises more easily than in the conventional example. As a result, the preheating time can be shortened, and running costs can be reduced. Furthermore, since the communication obstructing member 72 is made of an insulating material, even if the temperature of the bottom wall portion 11 of the heating chamber 1 rises, the temperature rise of the burner enclosure member 7 due to heat transfer via the communication obstructing member 72 is suppressed, and the durability of the burner enclosure member 7 can be improved.

[0024] Furthermore, in this embodiment, the gas burner 3 is positioned such that the upper surface of the combustion plate portion 311 is located below the upper surface of the bottom wall portion 11 of the heating chamber 1. As a result, the combustion flame generated on the combustion plate portion 311 approaches the upper surface of the bottom wall portion 11, promoting the heating of the bottom wall portion 11 and contributing to a reduction in preheating time.

[0025] Furthermore, in this embodiment, the upper end of the burner enclosure member 7 is positioned above the upper surface of the combustion plate portion 311 and below the upper surface of the bottom wall portion 11 of the heating chamber 1. This prevents the secondary air flowing into the burner enclosure member 7 from touching the peripheral wall surface of the burner installation hole 15, while bringing the combustion flame generated at a height above the upper end of the burner enclosure member 7 closer to the upper surface of the bottom wall portion 11, thereby further shortening the preheating time.

[0026] Furthermore, as shown in the embodiment in Figure 6, a guide member 16 may be provided in the heating chamber 1 to guide the combustion gas generated by the combustion of the gas ejected from the combustion plate 311 to a predetermined portion 11a on the upper surface of the bottom wall 11. This allows the temperature of the predetermined portion 11a on the upper surface of the bottom wall 11 to rise more quickly. As a result, by making the predetermined portion 11a the area where the food to be cooked is placed, the preheating time can be shortened as much as possible.

[0027] Although embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited thereto. For example, in the above embodiment, the communication obstructing member 72 is made of a plate attached to the lower surface of the bottom wall portion 11 of the heating chamber 1, but it is also possible to place the communication obstructing member 72 inside the burner installation hole 15. Furthermore, in the above embodiment, the gas burner 3 is a diffusion combustion type burner using hydrogen gas as the fuel gas, but it may also be a premixed type burner using a fuel gas other than hydrogen gas, such as natural gas or propane gas. [Explanation of Symbols]

[0028] 1...heating chamber, 11...bottom wall, 11a...predetermined portion of the upper surface of the bottom wall, 13...inlet / outlet, 15...burner installation hole, 16...guide member, 3...burner, 311...combustion plate, 7...burner enclosure member, 72...communication obstruction member.

Claims

1. A cooking appliance comprising a heating chamber for storing food to be cooked, having an entrance and exit for food to be cooked; a lower chamber located below the bottom wall of the heating chamber; and a gas burner having an upward-facing combustion plate for ejecting gas, which is inserted into a burner mounting hole formed in the bottom wall so as to extend from the heating chamber to the lower chamber, wherein food to be cooked is placed on the bottom wall and heated by the combustion of the gas burner, A cooking appliance characterized in that a burner enclosure member is installed within the burner installation hole, surrounding the gas burner with a gap for secondary air to flow around it, such that there is a gap between the peripheral wall surface of the burner installation hole and the burner enclosure member, and a communication obstructing member is provided to prevent communication between the heating chamber and the lower chamber through this gap.

2. The cooking appliance according to claim 1, characterized in that the communication-blocking member is made of an insulating material that suppresses heat conduction between the peripheral wall surface of the burner installation hole and the burner enclosure member.

3. The cooking appliance according to claim 1, characterized in that the gas burner is arranged such that the upper surface of the combustion plate portion is located below the upper surface of the bottom wall portion.

4. The heating cooker according to claim 3, characterized in that the upper end of the burner enclosure member is located above the upper surface of the combustion plate portion and below the upper surface of the bottom wall portion.

5. The heating appliance according to any one of claims 1 to 4, characterized in that a guide member is provided in the heating chamber that guides the combustion gas generated by the combustion of the gas ejected from the combustion plate to a predetermined portion of the upper surface of the bottom wall.

6. The cooking appliance according to any one of claims 1 to 4, characterized in that the gas burner is a burner that uses a diffusion combustion method for hydrogen gas.

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