Liquid heating conditioner

Abstract

The objective is to provide a liquid heating cooker that does not generate electrical discharges due to metal components used within the cooking unit during microwave heating. [Solution] The liquid heating cooker of the present invention places a non-conductive material such as ceramic material at the location of the holes in the top plate where sparks are most likely to fly, or makes all or at least part of the suspension members from a non-conductive material. By using non-conductive materials, even when microwaves are emitted, discharge does not occur due to the formation of incomplete contact between metal parts, thus preventing damage to the liquid heating cooker. When at least part of the suspension members is made of a non-conductive material, the position of the non-conductive part is controlled while considering the size of the liquid tank and food basket so that the non-conductive part of the suspension member aligns with the holes in the top plate when the food basket is lowered into the liquid tank to heat the food.

Description

Technical Field

[0002] ,

[0001] The present invention relates to an improvement of a commercial liquid heating cooker (for example, a fryer, a noodle cooker, etc.) used for heating frozen foods such as deep-fried foods and fried foods, and ingredients such as noodles in convenience stores, fast food restaurants, etc., and particularly relates to a liquid heating cooker using microwaves as a heating source.

Background Art

[0002] In convenience stores, etc., quick and efficient service is required, and it is desirable that a commercial heating cooker used for cooking frozen foods, etc. in the store has a heating means capable of heating ingredients quickly in a short time. Therefore, a heating method is adopted in which the molecules of a substance are vibrated by irradiating microwaves, and the temperature of the object is raised by the frictional heat. Heating using microwaves can heat in a short time because the temperature rises immediately after the start of heating due to rapid heating. Since it can be heated to the inside by the principle of heating the moisture contained in the substance, it is suitable for cooking fried foods, etc. in a short time such as heating frozen foods (for example, see Patent Document 1 below).

[0003] Unlike a microwave oven, in the case of a heating cooker that irradiates microwaves after immersing ingredients in the liquid in the heating tank, the ingredients are collectively placed on a predetermined food basket, and the food basket is put into the liquid tank for cooking, so a lifting device for moving the food basket up and down is required.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In liquid heating cookers, where food is heated to a high temperature by microwaves and the liquid in the heating chamber is also heated, the food basket on which the food is placed and the lifting mechanism, including the suspension components, are generally made of metal to withstand high temperatures and long-term operation. Furthermore, as demonstrated 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 metallic object inside the cooking unit of a microwave heating cooker, the microwaves will concentrate and sparks will be generated, damaging the liquid heating cooker. Metals have the property of reflecting radio waves, but at the same time, there are freely moving electrons on the surface of metals. When these electrons move violently due to microwave vibrations, they are ejected into the air and a discharge phenomenon occurs when they jump to other objects. In particular, electricity tends to accumulate in protruding parts, and it is said that discharge is more likely to occur when the edges of a metal are uneven.

[0006] The lifting mechanism of a liquid heating cooker uses a suspension member that hooks onto and supports the food basket, and a lift motor is used to move this suspension member up and down to immerse or lift the food basket into the liquid tank. In addition, to prevent microwaves from leaking to the outside, a top plate must be installed in the cooking unit to create a closed space. Due to ease of processing and cost considerations, a metal top plate is generally used, and when a metal suspension member is passed through a hole drilled in this top plate, incomplete contact is formed between the metal parts. As a result, microwaves are concentrated all at once, and the discharge phenomenon described above can generate sparks, which can damage the magnetron, or the heat from the discharge can cause holes in the waveguide, etc., leading to the risk of microwave energy leaking to the outside.

[0007] Therefore, the present invention aims to provide a liquid heating cooker that does not generate electrical discharges due to metal components used within the cooking unit during microwave heating cooking. [Means for solving the problem]

[0008] To solve the above problems, the liquid heating cooker of the present invention has a structure in which a suspension member that penetrates a hole provided in the top plate of the cooking unit engages with a food storage section on which food is placed, and a lift mechanism moves the suspension member up and down to raise and lower the food storage section, wherein all or at least part of the suspension member is made of a non-conductive material. When at least part of the suspension member is made of a non-conductive material, the position of the non-conductive part of the suspension member is controlled while considering the size of the liquid tank and the food basket so that the non-conductive part of the suspension member aligns with the hole in the top plate when the food basket is lowered into the liquid tank to heat the food. Furthermore, the above problems can also be solved by placing a non-conductive material such as ceramic material at the location of the hole in the top plate where sparks are likely to fly. [Effects of the Invention]

[0009] The liquid heating cooker of the present invention uses non-conductive materials, so even when microwaves are emitted, discharge does not occur due to the formation of incomplete contact between metal parts, thus avoiding damage to the liquid heating cooker. [Brief explanation of the drawing]

[0010] [Figure 1] This diagram shows the external view of a liquid heating cooker, which is one embodiment of the present invention, and a diagram showing the process of opening the door and removing the food basket. [Figure 2] This is a perspective view of the lifting mechanism for a liquid heating cooker. [Figure 3] This is a cross-sectional view of a liquid heating device. [Figure 4] This diagram shows the position of the suspension rod when the food basket is raised and lowered. [Figure 5] This figure shows an example of covering holes in the top panel with a non-conductive material. [Best Mode for Carrying Out the Invention]

[0011] Preferred embodiments of the present invention will be described in detail below with reference to the drawings. In this embodiment, a fryer is given as an example of a liquid heating device, but the invention is not necessarily limited to a fryer and can be applied to other liquid heating devices such as noodle boilers.

[0012] Figure 1 is an external view showing one embodiment of the fryer 100 and a diagram showing the process of opening the front door and removing the food basket. The fryer 100 consists of three parts: an upper section 1a, a middle section 1b, and a lower section 1c. The upper section 1a houses a lifting device, etc., and the front of the middle section 1b has a door, which opens to provide space for loading and unloading food baskets 12. The lower section 1c houses a liquid tank 7, and the front of the lower section 1c also has a door, which opens to check the state of the liquid tank 7. In addition, another section may be added below the lower section 1c to provide space for a liquid container when disposing of the liquid in the liquid tank 7.

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

[0014] The lifting device (not shown) has suspension rods 10 that engage with the food basket 12. Note that the lifting device itself can have any structure, so a detailed explanation is omitted. In this embodiment, there are four suspension rods 10 to suspend the food basket 12 from its four corners. The suspension rods 10 move up and down within the liquid heating cooker 100 by the lift motor of the lifting device, and as a result, the food basket 12 suspended from the lower ends of the suspension 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 suspension rod 10 in this embodiment is composed of two parts: a non-conductive portion 10a and a metal portion 10b. These parts are connected in any way to form a single rod. As shown in Figure 2, each suspension rod 10 moves up and down through a hole 9 provided in the top plate 8. The top plate 8 is a metal plate fixed to the ceiling of the food basket loading / unloading space located in the middle section 1b. The doors of the middle section 1b and the lower section 1c, along with the top plate 8, can create a closed space within the cooking unit. In other words, the top plate 8 forms the upper surface of the food basket loading / unloading space in the middle section 1b, and at the same time functions as a lid to prevent microwaves emitted from the microwave oscillator 3 in the upper section 1a from escaping from the cooking unit spaces in the middle section 1b and the lower section 1c.

[0016] The liquid tank 7 housed in the lower section 1c is a non-cylindrical tank composed of an upper tank 7a and a lower tank 7b in this embodiment, but it may also be a cylindrical tank. Both the upper tank 7a and the lower tank 7b in this embodiment are made of conductive stainless steel and are approximately rectangular in shape, 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 connects to the side wall and connects to the vertical side wall of the lower tank 7b. Cooking oil is stored from the bottom of the lower tank 7b up to a predetermined height in the upper tank 7a (position A shown in Figure 4). The size of the food basket 12 on which food 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 an outlet 14 for discharging the cooking oil in the oil tank 7 to the outside as waste oil. As shown in Figure 4, the bottom of the lower tank 7b has a sloped surface to facilitate the collection of crumbs that accumulate at the bottom, but it may also be horizontal.

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

[0018] The key point here is that, as mentioned above, in the position of the food basket 12 during cooking (i.e., while microwaves are being emitted) as shown in Figure 4(B), the suspension rod 10 is composed of a metal part and a non-conductive part, but the position is controlled so that the non-conductive part 10a of the suspension rod 10 passes through the hole 9 in the top plate 8. In Figure 4(B), the metal part 10b is located below the oil tank 7, and the non-conductive part 10a passes through the hole 9. During cooking, if the non-conductive part 10a of the suspension rod 10 passes through the hole 9 in the top plate 8, even if microwaves are being emitted, discharge will not occur due to the formation of incomplete contact between metal parts, thus avoiding the generation of sparks. During cooking (i.e., when the microwave is not oscillating), the metal part 10b may penetrate the position of the hole 9 opened in the top plate 8, or the non-conductive part 10a may penetrate in the same way as during cooking. FIG. 4(A) shows the case when the electromagnetic shielding guide pipe 11 is viewed in a perspective state, where the metal part 10b penetrates at the position of the hole 9 of the top plate 8, and a part of the connection part 10c and the non-conductive part 10a exists inside the electromagnetic 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 lateral sway when the food basket 12 on which the object to be cooked is placed is lifted up and down by the lifting rod 10. Above the hole 9, the lifting rod 10 is passed through the electromagnetic shielding guide pipe 11. As described above, the lifting rod 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 connection part 10c. The non-conductive part 10a and the metal part 10b can be separated at the connection part 10c. Therefore, a load is particularly likely to be applied to the connection part 10c, so the electromagnetic shielding guide pipe 11 guides the connection part 10c and the entire lifting rod 10. Also, when using ceramic for the non-conductive part 10a, the electromagnetic shielding guide pipe 11 serves to protect the impact-fragile ceramic. Therefore, it is desirable to adjust the lengths and the lifting and lowering amounts of the lifting rod 10 and the electromagnetic shielding guide pipe 11 so that the connection part 10c enters the electromagnetic shielding guide pipe 11. In other embodiments, the lifting rod 10 may be configured as a single lift support member with a structure in which the non-conductive part 10a and the metal part 10b cannot be separated, and the electromagnetic shielding guide pipe may not be provided.

[0020] In addition, when the frequency of the microwave used in the fryer 100 of the present embodiment is, for example, 2.45 GHz, the half wavelength is about 6 cm. Therefore, the diameter of the hole 9 in the top plate 8 through which the suspension rod 10 passes may be set to 6 cm or less so that the microwave does not pass through the hole 9. Certainly, in principle, microwaves do not pass through holes with a diameter of 6 cm or less. However, in reality, the frequency range of microwaves becomes wider, and there are microwaves that pass through holes with the set diameter length. Therefore, the electromagnetic shielding guide pipe 11 has a function of preventing the lateral sway when the suspension rod 10 is lifted up and down as described above, and also has a function of preventing the microwaves in the cooking unit from leaking to the outside through the hole 9 in the top plate 8. Regarding the length of the electromagnetic shielding guide pipe 11 from the viewpoint of preventing microwave leakage, any length may be used as long as the length allows the microwave to be sufficiently attenuated.

[0021] In the first embodiment described above, it was stated that by changing the material of the suspension rod 10 to a non-conductive material such as ceramic that is not metal, discharge can be prevented. However, 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. 5.

[0022] FIG. 5 is a schematic cross-sectional view when the inner wall surface of the hole 9 in the top plate 8 is covered with ceramic 15. The ceramic 15 may be attached to the inner wall surface using any adhesive or the like. Therefore, the top plate 8 may be provided with a hole having a diameter obtained by adding this thickness. However, it goes without saying that the thickness of the ceramic 15 can be arbitrary. As a result, even if the suspension rod 10 is entirely made of metal or the metal portion 10b passes through the hole 9 during the oscillation of the microwave, no discharge occurs. In addition, even when avoiding discharge by covering the inner wall surface of the hole 9 with a non-conductive material such as ceramic 15, it is desirable to attach the above-described electromagnetic shielding guide pipe 11 to reinforce the suspension rod 10.

[0023] In the case of the hole 9 shown in Figure 5, since its inner wall surface is made of a non-conductive material such as ceramic, the entire suspension rod 10 passing through the hole 9 may be made of metal (however, even if the inner wall surface is covered with ceramic or the like, the entire suspension rod 10 may be made only of the non-conductive portion 10a). Furthermore, dividing the suspension rod 10 makes maintenance easier. Even when the inner wall surface is covered with ceramic or the like, it is useful to have multiple suspension rods (for example, divided into two) rather than a single rod. As in the first embodiment, the suspension rod 10 may be composed of two parts, a non-conductive portion 10a and a metal portion 10b, or it may be further separated at a connecting portion 10c.

[0024] Although the present invention relates to a liquid heating cooker that uses microwaves as a heat source, an electromagnetic induction coil for electromagnetic induction heating may be placed around the bottom or sides of the liquid tank 7 as an additional heat source. In this case, it becomes possible to achieve rapid cooking by heating with microwave energy from efficient irradiation from a microwave oscillator and heating by convection of high-temperature cooking oil heated by electromagnetic induction. [Explanation of Symbols]

[0025] 3. Microwave Oscillator 7 Liquid tank 8 Top plate 9 holes 10 Hanging rods 10a Non-conductive portion of the suspension rod 10b Metal part of the suspension rod 10c Connection part of the hanging rod 11 Electromagnetically Shielded Guide Pipe 12 Food baskets 100 Fryers

Claims

1. A cooking unit including a liquid tank for storing liquid for heating food, wherein a space is formed above the liquid tank for loading and unloading food baskets on which food is placed, The cooking unit includes a microwave radiating unit that emits microwaves, A lift mechanism for raising and lowering the food storage section on which food is placed, In order to prevent the microwaves from being exposed to the outside, a metal top plate is provided on the top of the cooking unit, A liquid heating cooker equipped with, The lift mechanism includes a suspension member that engages with the food storage section, and the food storage section is raised and lowered by the vertical movement of the suspension member, which passes through a hole provided in the top plate. A liquid heating cooker wherein at least a portion of the suspension member includes a non-conductive portion, and the position of the suspension member is controlled so that the non-conductive portion of the suspension member is located at the position of the hole in the top plate during the period when microwaves are irradiated by the microwave radiating unit.

2. A cooking unit including a liquid tank for storing liquid for heating food, The cooking unit includes a microwave radiating unit that emits microwaves, A lift mechanism for raising and lowering the food storage section on which food is placed, In order to prevent the microwaves from being exposed to the outside, a metal top plate is provided on the top of the cooking unit, A liquid heating cooker equipped with, The lift mechanism includes a suspension member that engages with the food storage section, and the food storage section is raised and lowered by the vertical movement of the suspension member, which passes through a hole provided in the top plate. A liquid heating appliance in which the inner wall surrounding the through-hole in 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 suspension member passes.

4. The liquid heating cooker according to claim 1, wherein the suspension member has a non-conductive portion and a conductive portion integrated at a connection portion, and is detachable at the connection portion.

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

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