Liquid cooking appliance

Abstract

The object of the present invention is to provide a liquid heating cooker in which no discharge occurs due to metal parts used in a cooking unit during heating and cooking with microwaves. [Solution] In the liquid heating cooker of the present invention, a non-conductive material such as a ceramic material is placed at the position of the hole in the top plate where sparks are most likely to fly, or all or at least a part of the hanging member is made of a non-conductive material. By using a non-conductive material, even if microwaves are radiated, no discharge occurs due to the formation of incomplete contact between metal parts, so damage to the liquid heating cooker can be avoided. When at least a part of the hanging member is made of a non-conductive material, the position of the non-conductive part is controlled taking into account the size of the liquid tank and the food basket so that the non-conductive part of the hanging member matches the hole in the top plate when the food basket is lowered into the liquid tank to cook the ingredients.

Description

[Technical field]

[0001] The present invention relates to an improvement to commercial liquid heating cookers (e.g., fryers and noodle boilers) used in convenience stores, fast food restaurants, and the like to heat ingredients such as fried chicken, fried foods, and noodles, and in particular to a liquid heating cooker that uses microwaves as a heating source. [Background technology]

[0002] Convenience stores and other establishments are expected to provide fast and efficient service, and commercial cooking appliances used to cook frozen foods and the like in stores are desirably equipped with a heating means capable of heating ingredients in a short space of time. For this reason, a heating method is adopted in which microwaves are irradiated to vibrate the molecules of a substance, and the resulting frictional heat raises the temperature of the object. Heating using microwaves is rapid heating, with the temperature rising immediately after heating begins, so heating can be achieved in a short space of time. As it is possible to heat the inside of a substance by using the principle of heating the moisture contained in the substance, it is suitable for cooking fried foods in a short space of time, such as heating frozen foods (see, for example, Patent Document 1 below).

[0003] Unlike microwave ovens, cooking appliances that irradiate microwaves to food by immersing it in liquid in a heating tank require the food to be placed together in a designated food basket, and the food basket is then placed in the liquid tank to be cooked, necessitating a lifting device to move the food basket up and down. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2018 / 225859 Summary of the Invention [Problem to be solved by the invention]

[0005] In liquid heating cookers, where the food ingredients are heated to a high temperature by microwaves and the liquid in the heating tank is also heated, the food basket on which the food ingredients are placed and the lifting device including the hanging member are generally made of metal so that they can withstand high temperatures and long-term operation. Also, as shown by the phenomenon of sparks flying when aluminum foil is placed in a microwave oven and the power is turned on, if there is a metal material in the cooking unit of a microwave cooking cooker, the microwaves will concentrate and cause sparks, damaging the liquid heating cooker. Metals have the property of reflecting radio waves, but at the same time, there are freely mobile electrons on the surface of the metal, and as these move about violently due to the vibration of microwaves, they fly into the air and when they jump to another object, a discharge occurs. Electricity in particular tends to gather in protruding parts, and it is said that metals with uneven edges are more likely to discharge.

[0006] The lifting device of the liquid heating cooker uses a hanging member that hooks and supports the food basket, and uses a lift motor to move the hanging member up and down to immerse and lift the food basket into the liquid tank. In addition, in order to prevent microwaves from leaking to the outside, it is necessary to install a top plate on the cooking unit to create an enclosed space. A metal top plate is generally used because of its ease of processing and cost, and when a metal hanging member is passed through a hole opened in the top plate, an incomplete contact portion is formed between the metal parts. As a result, microwaves are concentrated all at once, and sparks are generated by the discharge phenomenon described above, which may damage the magnetron, or the heat from the discharge may open a hole in the waveguide, causing microwave energy to leak to the outside.

[0007] SUMMARY OF THE PRESENT EMBODIMENTS An object of the present invention is to provide a liquid heating cooker that prevents discharge from occurring due to metal parts used in a cooking unit during microwave cooking. [Means for solving the problem]

[0008] In order to solve the above problems, the liquid cooking device of the present invention has a structure in which a hanging member that passes through a hole in the top plate of the cooking unit engages with a food storage section on which food is placed, and a lift mechanism raises and lowers the food storage section by moving the hanging member up and down, and all or at least a part of the hanging member is made of a non-conductive material. When at least a part of the hanging member is made of a non-conductive material, the position of the non-conductive part is controlled while taking into account the size of the liquid tank and the food basket so that the non-conductive part of the hanging member matches the hole in the top plate when the food basket is lowered into the liquid tank to heat and cook the ingredients. In addition, the above problems can also be solved by arranging a non-conductive material such as a ceramic material at the position of the hole in the top plate where sparks are likely to fly. Effect of the Invention

[0009] The liquid heating cooker of the present invention uses non-conductive materials, so that even when microwaves are radiated, no discharge occurs due to the formation of incomplete contact between metal parts, thereby preventing damage to the liquid heating cooker. [Brief description of the drawings]

[0010] [Figure 1] 1A and 1B are external views of a liquid heating cooker according to an embodiment of the present invention, and a view showing a state in which a door is opened and a food basket is removed. [Diagram 2] FIG. 2 is a perspective view of a lifting device for a liquid heating cooker. [Diagram 3] FIG. 2 is a cross-sectional view of the liquid heating cooker. [Figure 4] 13 is a diagram showing the position of the hanging rod when the food basket is raised and lowered. FIG. [Diagram 5] 13 is a diagram showing an example in which a hole in a top plate is covered with a non-conductive material. FIG. BEST MODE FOR CARRYING OUT THEINVENTION

[0011] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In this embodiment, a fryer is taken as an example of a liquid heating cooker, but the present invention is not limited to a fryer and can be applied to other liquid heating cookers such as a noodle boiler.

[0012] FIG. 1 is an external view of an embodiment of a fryer 100 and a view showing a state where a front door is opened and a food basket is removed. The fryer 100 is composed of three parts, an upper part 1a, a middle part 1b, and a lower part 1c. The upper part 1a houses a lifting device and the like, and the middle part 1b has a door as an opening in front thereof, which opens to provide a space for loading and unloading a food basket 12. The lower part 1c houses a liquid tank 7, and the lower part 1c also has a door in front thereof, which opens to allow the state of the liquid tank 7 to be checked. Another step may be added below the lower part 1c as a space for placing a liquid container when disposing of the liquid in the liquid tank 7.

[0013] FIG. 2 is a perspective view of a part of the mechanism housed in the upper part 1a. FIG. 3 is a schematic cross-sectional view of the liquid heating cooker 100. In addition to the lifting device (not shown), the upper part 1a is equipped with a magnetron and a waveguide 4 built into a microwave oscillator 3. The microwaves from the magnetron are guided to the upper part of the top plate 8 by the waveguide 4, and are irradiated into the liquid tank 7 from an opening in the top plate 8 (the opening may be covered with a non-conductive thin plate such as a glass plate) while being stirred by rotating a microwave diffusion propeller 6 by a microwave stirring motor 5 arranged in the upper part of the top plate 8. The output and time of microwave irradiation can be controlled to change depending on the type and amount of the food material to be heated. In addition to the magnetron as the microwave oscillator 3, any device that generates desired microwaves can also be used as the microwave oscillator.

[0014] The lifting device (not shown) has a hanging rod 10 that engages with the food basket 12. Note that the lifting device itself may have any structure, so a detailed description is omitted. In the present embodiment, there are four hanging rods 10 for suspending the food basket 12 from the four corners. The hanging rods 10 move up and down within the liquid heating cooker 100 by a lift motor of the lifting device, and as a result, the food basket 12 suspended from the lower end of the hanging rods 10 moves up and down between the food basket loading / unloading space in the middle section 1b and the liquid tank 7 in the lower section 1c (hereinafter, the food basket loading / unloading space and the liquid tank 7 are collectively referred to as the "cooking unit space").

[0015] Each hanging rod 10 in this embodiment is composed of two parts, a non-conductive part 10a and a metal part 10b, and each part is connected by any connection method to form a single rod. As shown in FIG. 2, each hanging rod 10 moves up and down through a hole 9 provided in a top plate 8. The top plate 8 is a metal plate fixed to the ceiling of the food basket loading and unloading space located in the middle part 1b. The cooking unit space can be closed by the doors of the middle part 1b and the lower part 1c and the top plate 8. In other words, the top plate 8 forms the upper surface of the food basket loading and unloading space in the middle part 1b, and at the same time, functions as a lid to prevent the microwaves oscillated from the microwave oscillator 3 in the upper part 1a from escaping from the cooking unit space in the middle part 1b and the lower part 1c.

[0016] In this embodiment, the liquid tank 7 accommodated in the lower portion 1c is a non-cylindrical tank composed of an upper tank 7a and a lower tank 7b, but may be a cylindrical tank. In this embodiment, the upper tank 7a and the lower tank 7b are both made of conductive stainless steel and are substantially rectangular tube-shaped, with the lower tank 7b having a smaller horizontal cross-sectional area than the upper tank 7a. The bottom of the upper tank 7a has a horizontal bottom that is connected to the side wall and is connected to the vertical side wall of the lower tank 7b. Cooking oil is stored from the bottom of the lower tank 7b to a predetermined height of the upper tank 7a (position A shown in FIG. 4). The size of the food basket 12 on which the food material to be heated, such as frozen food, is placed is appropriately determined according to the shape of the upper tank 7a. The bottom of the lower tank 7b has a drain port 14 for discharging the cooking oil in the oil tank 7 to the outside as waste oil. As shown in FIG. 4, the bottom of the lower tank 7b has an inclined surface to make it easier to collect the waste that accumulates at the bottom, but it may be horizontal.

[0017] FIG. 4 shows the position of the hanging rod 10 when the food basket 12 is raised and lowered. FIG. 4(A) shows the state before or after cooking (i.e., while microwaves are not being generated). The lift motor of the lifting device pulls the hanging rod 10 upward so that the food basket 12 is in the food basket loading and unloading space in the middle section 1b. FIG. 4(B) shows the state during cooking (i.e., while microwaves are being generated). The hanging rod 10 is pulled downward so that the food basket 12 is immersed in the liquid tank 7 in the lower section 1c. A in the figure is the position of the liquid surface.

[0018] The point to note here is that, in the case of the position of food basket 12 during cooking (i.e., while microwaves are being oscillated) shown in Fig. 4(B), the hanging rod 10 is composed of a metal part and a non-conductive part as described above, but the position is controlled so that the non-conductive part 10a of the hanging rod 10 passes through the hole 9 in the top plate 8. The metal part 10b in Fig. 4(B) is below the oil tank 7, and the non-conductive part 10a passes through the hole 9. If the non-conductive part 10a of the hanging rod 10 passes through the hole 9 in the top plate 8 during cooking, even if microwaves are radiated, no discharge occurs due to the formation of an incomplete contact between metal parts, and therefore sparks can be avoided. When cooking is not in progress (i.e., when microwaves are not being oscillated), metal portion 10b may penetrate through the position of hole 9 in top plate 8, or non-conductive portion 10a may penetrate through as in cooking. Fig. 4(A) shows a see-through view of electromagnetically shielding guide pipe 11, illustrating a case in which metal portion 10b penetrates through the position of hole 9 in top plate 8, and connection portion 10c and part of non-conductive portion 10a are present inside electromagnetically shielding guide pipe 11.

[0019] The electromagnetic shielding guide pipe 11, made of metal or the like, installed above the hole 9 of the top plate 8 is for preventing the food basket 12 on which the food is placed from shaking sideways when the hanging bar 10 lifts up and down, and the hanging bar 10 passes through the electromagnetic shielding guide pipe 11 above the hole 9. As described above, the hanging bar 10 of this embodiment has a structure in which the non-conductive part 10a and the metal part 10b are connected and integrated by the connecting part 10c. The non-conductive part 10a and the metal part 10b can be separated at the connecting part 10c. Therefore, since the connecting part 10c is particularly likely to be subjected to a load, the connecting part 10c and the entire hanging bar 10 are guided by the electromagnetic shielding guide pipe 11. In addition, when ceramic is used for the non-conductive part 10a, the electromagnetic shielding guide pipe 11 plays a role in protecting the ceramic, which is vulnerable to impact. Therefore, it is desirable to adjust the length and the amount of elevation of the suspension rod 10 and the electromagnetic shielding guide pipe 11 so that this connection portion 10c enters inside the electromagnetic shielding guide pipe 11. In other embodiments, the suspension rod 10 may be configured as a single lift support member with the non-conductive portion 10a and the metal portion 10b being inseparable, and it is also possible that an electromagnetically shielded guide pipe is not provided.

[0020] In addition, when the frequency of the microwave used in the fryer 100 of this embodiment is, for example, 2.45 GHz, the half wavelength is about 6 cm, so the diameter of the hole 9 in the top plate 8 through which the hanging rod 10 passes can be set to 6 cm or less to prevent the microwave from passing through the hole 9. In principle, the microwave will not pass through a hole with a diameter of 6 cm or less, but in reality, the microwave frequency range is wide and some microwaves pass through a hole with a set diameter. Therefore, the electromagnetic shielding guide pipe 11 has the function of preventing the lateral shaking of the hanging rod 10 when it is lifted up and down as described above, and also has the function of preventing the microwave in the cooking unit from leaking out to the outside through the hole 9 in the top plate 8. From the viewpoint of preventing leakage of microwaves, the length of the electromagnetic shielding guide pipe 11 may be any length as long as the microwaves are sufficiently attenuated.

[0021] In the above-mentioned first embodiment, it was described that discharge is prevented by changing the material of the hanging rod 10 to a non-conductive material such as ceramic, which is not a metal, but in the fryer of the second embodiment, the inner wall of the hole 9 in the top plate 8 is covered with a non-conductive material. An example of using a non-conductive material such as ceramic is shown in FIG.

[0022] FIG. 5 is a schematic cross-sectional view of the inner wall surface of the hole 9 of the top plate 8 covered with the ceramic 15. The ceramic 15 can be attached to the inner wall surface using any adhesive or the like. Therefore, the top plate 8 should be provided with a hole with a diameter that includes the thickness of the ceramic 15. However, it goes without saying that the thickness of the ceramic 15 can be set arbitrarily. As a result, even if the suspension rod 10 is made entirely of metal or the metal part 10b passes through the hole 9 during microwave oscillation, no discharge occurs. Even if discharge is avoided by covering the inner wall surface of the hole 9 with a non-conductive material such as the ceramic 15, it is desirable to reinforce the suspension rod 10 by attaching the electromagnetic shielding guide pipe 11 described above.

[0023] In the case of hole 9 shown in FIG. 5, since its inner wall surface is made of a non-conductive material such as ceramic, the hanging rod 10 passing through hole 9 may be made entirely of metal (even if the inner wall surface is covered with ceramic or the like, the entire hanging rod 10 may be made of only the non-conductive portion 10a). Furthermore, maintenance becomes easier if the hanging rod 10 is divided. Even when the inner wall surface is covered with ceramic or the like, it is useful to make the hanging rod 10 multiple (for example, divided into two) instead of one piece, and the hanging rod 10 may be configured as two parts, the non-conductive part 10a and the metal part 10b, as in the first embodiment, and may be further separated at the connecting part 10c.

[0024] Although the present invention relates to a liquid heating cooker that uses microwaves as a heating source, an electromagnetic induction coil for electromagnetic induction heating may be disposed as an additional heating source so as to surround the bottom or side of the liquid vat 7. In this case, heating by microwave energy generated by efficient irradiation from a microwave oscillator and heating by convection of high-temperature cooking oil heated by electromagnetic induction make it possible to realize heating and cooking in a short time. [Explanation of symbols]

[0025] 3. Microwave Oscillator 7 Liquid tank 8. Top plate 9 holes 10 Hanging rod 10a Non-conductive parts of the suspension rod 10b Metal part of the hanging rod 10c Hanging rod connection 11 Electromagnetic shielding guide pipe 12 Food Basket 100 Flyer

Claims

1. A cooking unit including a liquid tank for storing a liquid for heating food, the cooking unit having a space formed above the liquid tank for carrying in and out a food basket on which food is placed; A microwave radiating unit that radiates microwaves to the cooking unit; a lift mechanism for raising and lowering a food storage unit on which food is placed; a metal top plate provided on the upper part of the cooking unit to prevent the microwaves from being exposed to the outside; A liquid heating cooker comprising: The lift mechanism includes a hanging member that engages with the food storage unit, and the food storage unit is raised and lowered by the vertical movement of the hanging member that passes through a hole provided in the top plate, At least a portion of the hanging member includes a non-conductive portion, and the position of the hanging member is controlled so that the non-conductive portion is present at the position of the hole in the top plate during the period when microwaves are irradiated by the microwave radiation unit.

2. a cooking unit including a liquid tank for storing a liquid for heating food; A microwave radiating unit that radiates microwaves to the cooking unit; a lift mechanism for raising and lowering a food storage unit on which food is placed; a metal top plate provided on the upper part of the cooking unit to prevent the microwaves from being exposed to the outside; A liquid heating cooker comprising: The lift mechanism includes a hanging member that engages with the food storage unit, and the food storage unit is raised and lowered by the vertical movement of the hanging member that passes through a hole provided in the top plate, The inner wall of the through hole of the top plate is covered with a non-conductive material.

3. The liquid heating cooker according to claim 1 or 2, further comprising a hollow electromagnetically shielded guide pipe above the top plate through which the hanging member passes.

4. The liquid heating cooker according to claim 1 , wherein the hanging member has a non-conductive portion and a conductive portion which are integrated at a connection portion and which are separable at the connection portion.

5. The liquid heating cooker according to claim 2 , wherein the hanging member is composed of a plurality of detachable parts.

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