Sweet potato roaster

Abstract

To provide a potato baking machine which enables baking to make delicious baked potatoes and can be handled easily.SOLUTION: A potato baking machine 1 includes: a baking chamber 7 for baking baked potatoes; a tray 80 on which the potatoes arranged in the chamber are placed; and electric heating means 71, 81 which heat the interior of the chamber. Further, the potato baking machine 1 includes: a sheath heater 81 disposed at a lower part of the baking chamber interior 72; a heat plate 79 which is formed of a far-infrared emission material formed with a number of hot air rising holes 79k dispersed; and small cobble stones 77 placed on the plate. Further, the potato baking machine 1 includes a far-infrared heater 71 disposed at an upper part of the chamber interior 72.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a sweet potato roaster that can roast sweet and delicious baked sweet potatoes. In particular, it relates to a safe, electrically heated sweet potato roaster suitable for installation in convenience stores, supermarkets, etc. It also relates to a sweet potato roaster that is easy to clean and use, allows for uniform roasting, is energy-efficient, and has excellent heat retention. [Background technology]

[0002] Roasted sweet potatoes have long been a favorite food in Japan during the cold season. Many older people will have the experience of roasting sweet potatoes while burning fallen leaves. Mobile roasted sweet potato vendors, which in the past were wheeled around on handcarts and in modern times are equipped with stone ovens and load them onto light vehicles, are a symbol of winter, with the sound of "roasted sweet potatoes, ishi-yakimo" yelling from their loudspeakers.

[0003] The fuel for the stone ovens in mobile food trucks used to be firewood, but in recent years it has been gas. Many commercial sweet potato roasters also used gas fuel in the past. However, in recent years, supermarkets and small stores have mainly used electric sweet potato roasters, which have fewer restrictions in terms of disaster prevention and installation.

[0004] Traditionally, the sweet potato varieties most commonly eaten for roasting were "Beni-Azuma," "Naruto-Kintoki," and "Annou-imo." In recent years, "Silk Sweets" and "Beni-Haruka" have become popular. In particular, "Beni-Haruka" is said to have sparked the recent roasted sweet potato boom, with its sticky flesh and sweetness appealing to a wide range of consumers.

[0005] The sweetness of baked sweet potatoes is said to be due to the following two factors. The first is that sweet potato starch is saccharified and converted into free sugars such as sucrose during storage and ripening after harvest. The second is that during cooking of sweet potatoes, the saccharifying enzyme β-amylase saccharifies gelatinized starch to produce maltose at temperatures between 65 and 75°C. Patent Document 1 proposes "performing a first heating step in which heat treatment is carried out at 65 to 70°C for a predetermined period of time, and after this first heating step, a second heating step in which heat treatment is carried out for a predetermined period of time using superheated steam at 135 to 140°C in the cooking chamber 12," wrapping the sweet potatoes in the above temperature range. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2013-165698 DISCLOSURE OF THE INVENTION [Problem to be solved by the invention]

[0007] The following are some of the areas that need improvement in the current sweet potato roasters. (1) Place multiple sweet potatoes (for example, 5 or 6) in the oven and bake them under uniform conditions (temperature, time, degree of exposure to far infrared rays, etc.) until they are cooked to a good, uniform state (sweetness, aroma, stickiness, chewiness, etc.). (2) Utilizing residual heat from the baking oven to keep baked sweet potatoes warm, saving energy and improving the ability to maintain the appropriate temperature.

[0008] (3) Improved temperature uniformity over time and space due to improved insulation and heat storage in the baking chamber and heat retention section. (4) Easy to clean: The honey dripping from the sweet potatoes and the residue of the sweet potato skins that accumulate at the bottom of the baking chamber can be cleaned easily and with little effort. (5) In particular, in anticipation of the situation where part-time workers will be handling sweet potato roasters at many convenience stores, the measures will be taken to make them easy to use and to ensure safety.

[0009] An object of the present invention is to provide a sweet potato roaster that can bake delicious sweet potatoes and is easy to handle, while addressing the above-mentioned points that need improvement. [Means for solving the problem]

[0010] In this "Means for Solving the Problem" and "Claims," ​​reference symbols for various parts in the attached drawings are shown in parentheses, but this is for reference only and is not intended to limit the scope of the rights to those in the attached drawings.

[0011] The first sweet potato roaster (1) of the present invention comprises a baking chamber (7) for baking sweet potatoes, a tray (80) arranged in the baking chamber on which the sweet potatoes to be baked are placed, and electric heating means (71-81) for heating the interior of the baking chamber, characterized in that it comprises a sheathed heater (81) as a lower heating means arranged in the lower part of the interior space of the baking chamber (7), a heat plate (79) made of a far-infrared emitting material and having a large number of dispersed hot air rising holes (79k) spread over the sheathed heater, and a large number of small pebbles (77) placed on the heat plate, and a far-infrared heater (71) as an upper heating means arranged in the upper part of the interior space of the baking chamber (7).

[0012] The sweet potato roaster (1) is typically used to roast sweet potatoes, but is not limited to this. Corn, potatoes, etc. can also be roasted. In the following explanation, sweet potatoes will be used as a typical example of roasted foods.

[0013] The potatoes P are placed side by side on the small stones (77). The potatoes receive far infrared rays from the far infrared heater (71) from above, and from the small stones and heat plate (79) from below. This allows the potatoes to be baked moist and delicious while maintaining their moisture. In other words, far infrared rays have a high heat permeability to food, so they are less likely to be heated locally near the surface, and have the property of suppressing the evaporation of moisture that would otherwise be caused by concentrated heating. This allows for a good baking state, known as "slow baking," or "juicy on the inside and golden brown on the outside."

[0014] Sheathed heaters (81) are relatively inexpensive and are commercially available in a variety of specifications (materials and temperature conditions). For general grilling, a typical sheathed heater with a nichrome wire heating element can be used, which can raise the surface temperature to about 500-600°C and has a stainless steel sheath (which is corrosion-resistant against the honey dripping from the sweet potato).

[0015] The heat plate (79) is preferably made of a corrosion-resistant material with high thermal radiation. For example, a hot-dip aluminized steel plate with an aluminum oxide surface layer is preferable, including from an economical standpoint. Examples of the dimensions and arrangement of the hot air rise holes (79k) will be explained in the embodiment of the invention. The heat plate (79) efficiently and uniformly heats the small pebbles (77) placed on the plate by "rapid heat conduction" and the "heat escape effect" of the hot air rise holes (79k).

[0016] From the viewpoint of improving the temperature uniformity in the space in the baking chamber (7) where the sweet potatoes P are placed, it is preferable that in the sweet potato roaster (1), the sheathed heater (81) is arranged along a line that surrounds the center of the chamber in a plan view, and that the hot air rising holes (79k) of the heat plate (79) are not formed in the center of the chamber in a plan view. Data on the temperature uniformity will be described later with reference to Figure 10. This makes it possible to sufficiently heat the peripheral parts of the baking chamber while preventing excessive heating in the center, thereby achieving a uniform temperature inside the chamber.

[0017] The small stones (77) have rounded edges so that they do not damage the sweet potatoes placed on them. They are 10mm to 30mm in size, and Nachikuro stone is preferable as it has high far-infrared radiation and is less likely to break and scatter. The small stones radiate far-infrared radiation when heated, and their heat storage effect allows them to maintain a stable heating state without cooling down. Furthermore, the "uniform far-infrared radiation" emitted from the small stones allows the sweet potatoes to be cooked thoroughly and evenly.

[0018] The far-infrared heater (71) irradiates the sweet potatoes directly with far-infrared rays from above. The soft far-infrared rays, like those emitted by a hot ember, allow the sweet potatoes to be deliciously roasted. It is preferable to provide a reflector (72) above the far-infrared heater (71) to diffuse the far-infrared rays and irradiate the entire oven interior. It is also preferable to provide a protective wire mesh (73) below the far-infrared heater (71). This prevents the far-infrared heater from being damaged by the tongs (see Figure 9(A)) used to handle the sweet potatoes.

[0019] The second sweet potato roaster of the present invention comprises a baking chamber (7) for baking sweet potatoes, a tray (80) arranged inside the baking chamber on which the sweet potatoes to be baked are placed, heating means (71-81) for raising the temperature inside the chamber, a casing (5) for accommodating the baking chamber (7), and a heat retention section (3) arranged above the baking chamber for keeping the baked sweet potatoes P warm, and is characterized in that an air flow path (5f) is formed between the outer wall (7j) of the baking chamber (7) and the outer wall (5b) of the casing (5), and the air in the air flow path (5f) is heated by radiant heat emitted from the outer wall (7j) of the baking chamber and is led to the heat retention section (3).

[0020] Radiant heat (residual heat) from inside the baking chamber (7) is used to efficiently transfer heat to the warming section. This eliminates the need for a separate heater for the warming section (3), resulting in energy savings and reduced running costs. Specific examples of the warming section (3) and its heating structure will be described later with reference to Figure 4.

[0021] The third sweet potato roaster of the present invention comprises a baking chamber (7) for baking sweet potatoes, a tray (80) arranged inside the baking chamber on which the sweet potatoes to be baked are placed, and a heating means (81) arranged below the tray (80) for raising the temperature inside the baking chamber, and is characterized by further comprising a removable dust catcher (83) that is arranged to extend below the tray (80) and the heating means (81), is slidable forward and backward at the bottom of the baking chamber, and is provided.

[0022] The fourth sweet potato roaster of the present invention comprises a baking chamber (7) for baking sweet potatoes, a door (6) for opening and closing the baking chamber, a tray (80) arranged inside the baking chamber on which the sweet potatoes to be baked are placed, and a heating means (81) for raising the temperature inside the baking chamber, and is characterized by further comprising a removable sill support (85) arranged below the door (6) for receiving dew D that adheres to and falls from the door.

[0023] The syrup that drips during baking of sweet potato P and burnt residue are collected all at once in the garbage collector (83) at the bottom of the baking chamber. The garbage collector is slidable forward and backward and is removable, so it can be removed and washed with water. The specific structure of the garbage collector (83) and sill collector (85) will be explained with reference to Figures 5 and 6.

[0024] Condensation dripping from the door (6) is caught by the sill (dew) receiver (85). When the door (6) is opened, it is cooled by the indoor atmosphere, so the temperature tends to drop. When the door is closed, the moisture in the air inside the oven, which has become humid due to the evaporation of moisture from the sweet potatoes, tends to condense on the door surface. If this condensation drips down from the door, it will stain the counter of the store where the sweet potato roaster is installed. A sweet potato roaster with a sill receiver (85) prevents such staining, keeping the store clean. The accumulated sill can be disposed of in the sink by removing the sill receiver from the sweet potato roaster.

[0025] The fifth sweet potato roaster of the present invention comprises a baking chamber (7) for baking sweet potatoes, a door (6) for opening and closing the baking chamber, and heating means (71 / 81) for raising the temperature inside the baking chamber, and is characterized in that the lower end of the door (6) is supported by a torque hinge (67) so that it can be forcibly rotated in a range from closed to half-open but cannot rotate under its own weight, and can rotate under its own weight in a range from half-open to fully open.

[0026] The sweet potato roaster (1) is preferably further provided with a magnet (69) that attracts and biases the door (6) toward the baking chamber (7) (toward the rear) when the door (6) is in the closed position.

[0027] This type of sweet potato roaster is provided with a torque hinge (67) as a safety mechanism to ensure that the door (6) opens slowly. Without the torque hinge, if the door were to be pulled by hand and forcefully opened fully, the operator would be hit by a flood of hot air and steam. Also, if the door (6) were to be opened forcefully and fall down, the door could collide with a person's body and cause injury. The torque hinge (67) prevents such undesirable situations.

[0028] A magnet (69) ("magnetic catch") that attracts and biases the door (6) toward the baking chamber (7) (toward the back) securely holds the door closed. While it's rare, sweet potatoes may explode during baking. If the door were to open too quickly, it could hit someone (a store employee) and cause injury or cause them to drop something they're holding. The magnetic catch and / or torque hinge prevent the door (6) from opening suddenly and unintentionally. [Effects of the Invention]

[0029] According to the present invention, it is possible to provide a sweet potato roaster that can bake delicious sweet potatoes, or a sweet potato roaster that is easy to handle and safe, and also a sweet potato roaster that has other features. [Brief explanation of the drawings]

[0030] [Figure 1]1 is a side view showing the overall configuration of an electric sweet potato roaster 1 according to an embodiment of the present invention. [Figure 2] FIG. 2 is a front view of the sweet potato roaster 1 of FIG. [Figure 3] FIG. 2 is a plan view of the heat plate 79 of the sweet potato roaster 1 of FIG. [Figure 4] 4A and 4B are diagrams for explaining the details of the heat retention section 3 and its heating structure (mechanism for utilizing residual heat from the baking chamber) of the sweet potato roaster 1 in Fig. 1. Fig. 4A is a side view of the entire heat retention section 3. Fig. 4B is a schematic enlarged cross-sectional view for explaining the operation of the mechanism for utilizing residual heat. [Figure 5] 2 is a side cross-sectional view showing the structure of a dust tray 83 and a sill tray 85 in the sweet potato roaster 1 of FIG. 1. FIG. [Figure 6] Figure 6(A) is a perspective view of the sweet potato roaster of Figure 5 with the dust tray 83 removed. Figure 6(B) is a perspective view of the sweet potato roaster of Figure 5 with the sill support 85 removed. [Figure 7] 2A and 2B are diagrams for explaining the details of the door 6 of the baking chamber 7 of the sweet potato roaster 1 of FIG. 1, in which (A) is a side cross-sectional view and (B) is a perspective view in an open state. [Figure 8] 1. FIG. 4 is a side view illustrating the drawer structure of the sweet potato tray 80 of the sweet potato roaster 1 of FIG. [Figure 9] This is a perspective view for explaining the pull-out structure of the sweet potato tray 80 in Fig. 8. Fig. 8(A) shows the state in which the tray 80 is about to be pulled out with tongs 171 (no sweet potatoes are placed on it), and Fig. 8(B) shows the state in which sweet potatoes P are placed on it. [Figure 10] This is comparative data of the temperature distribution on the heat plate and small boulders when the distribution of hot air rising holes 79k on the heat plate 79 is different. [Explanation of symbols]

[0031] 1; Sweet potato roaster, 3; Heat retention part, 34; Interior, 37; Small pebbles 38; insulation board, 38d; vent, 38f; air passage, 38h; downward rib, 381; wall board 39; door, 39b; hinge, 39z; opening and closing knob, 41; heat protector 5; casing, 5b; outer wall (rear side panel, decorative side panel), 5f; air flow path (side air flow path) 5g; louver, 5j; upper air passage, 5s; front end, 5t; front side, 5x; front lower part 5z: Upper part of door opening 51; heat collection plate, 51b; burring hole, 51j; back part, 51m; hanging part 6; door, 61; handle, 62; insulation layer, 63; insulation block, 65; door frame, 65b; front plate, 65d; bracket, 65g; side plate, 67; Torque hinge, 69; Magnet (magnetic catch) 7; Kiln, 7b; Ceiling, 7b'; Side panel, 7c; Bracket, 7d; Top panel, 7g; Heat insulating layer, 7j; Outer wall (back panel), 7v; Slope eave, 7x; Hollow box beam, 7z; Bottom plate 71; far-infrared heater (heating means), 72; inside the cabinet, 73; protective wire mesh, 74; reflector, 75; slider, 75g; slider lower surface, 75k; moving roller, 751; leading edge member 76; fixed rail, 76b·76f; guide rail surface, 76j; fixed roller 77; small boulders, 79; heat plates, 79k; hot air risers, 80; tray, 81; sheath heater (heating means), 81b; end 83; garbage collection tray, 83b; knob, 83c; front flat belt, 83f; garbage collection pan, 83h; embankment wall 85; sill support, 85b; wall edge, 85f; bottom surface, 85j; wall edge, 85p; end piece, 85q; hole, 85s; wall edge, 91; Operation panel, 93; Electrical equipment, 171; Tongs

[0032] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In each drawing, the "up" and "down" directions indicated by the arrows are directions along the Earth's gravity. "Forward" is the side in front of the baking oven door 6 and the operation panel 91 where the operator (such as a convenience store or supermarket clerk) stands. "Back" is the direction farther from the operator's perspective (the back of the baking oven 1). "Left" and "right" are the left and right directions when the operator is facing the sweet potato roaster 1.

[0033] First, the overall configuration of a sweet potato roaster 1 according to an embodiment of the present invention will be described with reference to its side view in Fig. 1 and its front view in Fig. 2. The sweet potato roaster 1 of this embodiment is a relatively small device intended primarily for convenience stores, capable of roasting five or six large sweet potatoes in a roasting chamber 7. This sweet potato roaster 1 is broadly composed of a main casing 5, a baking chamber 7, a warming section 3, an operation panel 91, and an electrical section 93, which will be described below.

[0034] The main casing 5 is a generally square box made of stainless steel plate (as an example), and the baking chamber 7 is placed inside it. The back, top, bottom, left and right sides of the baking chamber 7 are covered with a heat insulating layer 7g (made of ceramic wool board). Inside the baking chamber 7, a far-infrared heater 71 is installed at the top and a sheathed heater 81 is installed at the bottom, creating a space within the chamber 72 that can be heated to approximately 200 to 300°C. Details of the heating mechanism of the baking chamber 7 will be described later.

[0035] An openable and closable door 6 is provided at the front side of the baking chamber 7. A tray 80 for placing potatoes P to be baked and cooked is provided at the bottom of the baking chamber 7 (above the sheath heater 81) and is slidable from front to back. Details of the door 6 will be described later with reference to Figure 7. Details of the tray 80 drawer mechanism will be described later with reference to Figure 8.

[0036] The warming section 3 is mounted on the main casing 5 above the baking chamber 7. The warming section 3 is where the sweet potatoes P baked in the baking chamber 7 are kept warm. By storing baked sweet potatoes in this warming section 3, the capacity to handle peak sales of baked sweet potatoes is increased. The side walls (four sides) and top of the warming section 3 are made of a transparent case 34, allowing customers to see the sweet potatoes inside clearly and encouraging them to purchase. The warming section 3 also keeps the baked sweet potatoes inside at a temperature of around 70°C, which is the active range for β-amylase, and has the effect of increasing the sugar content of the baked sweet potatoes. Details of the warming section 3 and its heating mechanism (baking chamber residual heat utilization mechanism) will be described later with reference to Figure 4.

[0037] The operation panel 91 is located at the front and below the baking chamber door 6. The operator operates this operation panel 91 to adjust the temperature of the baking chamber 7. Behind the operation panel 91, below the baking chamber 7, is the electrical equipment section 93, which houses electrical equipment such as heater power supplies and control boards.

[0038] Next, the heating means of the baking chamber 7 will be described in detail. Two rod-shaped far-infrared heaters 71 are arranged parallel to each other in the front-rear direction, extending left and right, at the top of the interior 72 of the baking chamber 7. The left and right ends of the heaters 71 are held by brackets 7c hanging from the left and right ends of the interior ceiling 7b (a thin stainless steel plate). The output of the far-infrared heaters 71 installed in the sweet potato roaster 1 of this example is 300W, for a total of 600W for the two heaters.

[0039] The far-infrared heater 71 is a quartz tube with a carbon filament sealed inside. A reflector 74 (for example, a stainless steel mirror-finished plate) is attached to the interior ceiling above the heater 71. The reflector 74 reflects the far-infrared rays emitted upward or diagonally upward from the heater 71 downward (towards the potatoes P). The underside of the heater 71 is covered with a protective wire mesh 73 to protect the heater from contact with tongs (see reference numeral 171 in Figure 9) used to hold and handle the potatoes inside the oven 72. The protective wire mesh 73 is, for example, a stainless steel wire mesh.

[0040] The far-infrared heater 71 irradiates the sweet potato P directly from above with far-infrared rays. The soft far-infrared rays emitted from the heater, like embers, and the far-infrared rays emitted by the small stones 77 (details will be described later), allow the sweet potato to be deliciously roasted.

[0041] Next, we will explain the heating structure of the lower part of the baking chamber 7. The sweet potato roaster 1 of this embodiment is equipped with a sheathed heater 81 as a lower heating means disposed below the chamber space where sweet potatoes P are baked, a heat plate 79 with numerous hot air rising holes 79k dispersed over the sheathed heater, and numerous small pebbles 77 placed on the heat plate.

[0042] In this example, the sheath heater 81 is a common, economical type with a sheath (protective tube) made of SUS304 and a heater wire made of nichrome wire. Some models have a maximum specification temperature of over 800°C, but those used for roasting sweet potatoes are heated to around 550°C. The chemical properties of the sheath material ensure good corrosion resistance at the above temperature against the syrup dripping from the sweet potatoes being roasted.

[0043] The sheathed heater 81 has a generally mushroom-shaped (upside down) planar shape as shown in Fig. 3. End 81b of heater 81 is inserted into the baking chamber 7, penetrating the lower right wall and right insulating layer 7gR of the baking chamber 7, as shown in Fig. 2. Inside the baking chamber 7, as shown in Fig. 3, it curves and protrudes toward the front and rear, extends leftward (downward in Fig. 2) from the front and rear portions of the heat plate 79, and extends toward the front and rear from the front portion of the left side of the heat plate 79.

[0044] The quantitative and specific planar shape of the sheathed heater 81 and the arrangement of the hot air rising holes 79k of the heat plate 79 (described below) are determined through tests in order to make the temperature inside the baking chamber 7 as uniform as possible. An example of temperature data will be described later with reference to the graph in FIG. 10.

[0045] As shown in Figures 1 and 2, the heat plate 79 is arranged above the sheath heater 81, extending over almost the entire lower part of the baking chamber 7. As shown in Figure 3, the heat plate 79 is a flat, rectangular member. In this example, the plate 79 is a steel plate with an aluminum oxide surface layer, such as Nippon Steel Corporation's "Alsheet," a hot-dip aluminum-plated steel plate. The aluminum oxide surface of this "Alsheet" provides high corrosion resistance and stain resistance. Furthermore, the surface has a reflectivity of approximately 80% at temperatures below approximately 450°C.

[0046] The four sides of the plate 79 are folded back to increase bending strength. The left, right, front and rear four sides of the plate 79 rest on the sliders 75 of the drawer tray 80, as shown in Figure 2. The plate 79 can be pulled out together with the sliders 75 (described later with reference to Figures 8 and 9). Ultimately, the heat plate 79 is a member that exhibits thermal properties and far-infrared radiation properties, and at the same time, it is a structural member that supports the small stones 77 and the sweet potatoes P to be roasted.

[0047] The heat plate 79 has a large number of round holes (hot air rising holes) 79k in a plan view. The holes 79k have a diameter of 3 to 10 mm, for example 5 mm. The holes 79k are distributed, for example, at a hole pitch of 7 mm in a staggered pattern (off-center). As shown in FIG. 3, the holes 79k of the plate 79 are not provided in the center (central) part of the oven. The central part without holes 79k has a width x length that is, for example, approximately 1 / 3 to 1 / 5 of the central part. The area without holes 79k of the plate 79 includes the areas immediately adjacent to the four sides and the central part.

[0048] The sheathed heater 81 is arranged around the center of the oven, roughly along the center of the area where the hot air rise holes 79k are located on the heat plate 79. This configuration prevents excessive temperature rise in the center of the baking oven 7, while also ensuring sufficient temperature rise in the peripheral areas of the baking oven, ensuring uniform heating of the oven (example data will be described later with reference to Figure 10).

[0049] Small marbles 77 and the sweet potatoes P placed on them are placed on the heat plate 79. Hot air from the sheathed heater 81 below rises through the numerous hot air rising holes 79k of the heat plate 79, raising the temperature inside the baking chamber 7. Furthermore, the heat plate 79 itself has excellent heat ray radiation properties, and heats the sweet potatoes P either through the small marbles 77 or directly with heat rays containing a large amount of far infrared rays. In other words, the heat plate 79 heats the small marbles efficiently and uniformly through its "fast heat conduction" and "heat escape hole effect."

[0050] Small stones 77 are rounded stones (with curved surfaces). Because they have no corners, they do not damage the potatoes placed on top. Dimensions of approximately 10mm to 30mm are easy to use, as they make it easy to hold irregularly shaped sweet potatoes without damaging any part of them. Small stones with a smooth surface, such as Nachi black stones or black stones, are preferred. Furthermore, stones that emit a lot of far infrared rays when heated and do not break and scatter even at high temperatures are preferred. Small stones also have a heat-storing effect and do not drop in temperature much, so they minimize fluctuations in the temperature inside the oven and provide a stable heating effect.

[0051] The sweet potato roaster 1 of this embodiment can roast sweet potatoes P evenly and moistly and deliciously, using the "uniform radiant heat and far-infrared effect" emitted from the small stones 77 and heat plate 79 from below, and the far-infrared heater from above, to roast the sweet potatoes evenly and maintain their moisture.

[0052] Next, the details of the heat retention section 3 of the sweet potato roaster 1 in Figure 1 and its heating structure (mechanism for utilizing residual heat in the baking chamber 7) will be described with reference to Figure 4. Figure 4(A) is an overall side view, and Figure 4(B) is a schematic enlarged cross-sectional view of the mechanism for utilizing residual heat in the baking chamber 7.

[0053] In this sweet potato roaster 1, a heat retention section 3 is installed above a baking chamber 7 in which baked sweet potatoes are baked. The baking chamber 7 is placed inside a casing 5. The baking chamber 7 is equipped with a heating means 71 inside the chamber to raise the temperature inside the chamber. A distinctive feature of this configuration is that an air flow path 5f is formed between the outer wall 7j of the baking chamber 7 and the outer wall 5b of the casing 5, and the air in the air flow path 5f is heated by radiant heat emitted from the outer wall 7j of the baking chamber (outside the insulating layer 7g) and is then led to the heat retention section 3. In other words, the heat retention section 3 is heated by the residual heat from the baking chamber 7.

[0054] The heat retention unit 3 has a case 32 made of transparent resin. The case 32 is shaped like a square box overall and is placed on top of the casing 5. An LED light 31 is attached to the top of the heat retention unit case 32 to illuminate the inside of the heat retention unit 3. The heat retention unit case 32 covers the space above a heat retention plate 38, which will be described later, and forms a space for keeping the baked sweet potatoes P warm and displaying them.

[0055] In the sweet potato roaster 1 of this embodiment, the planar area of ​​the warming space in the warming section 3 is approximately 1.8 times the planar area of ​​the baking chamber 7 (tray 80), making it larger. Eight to ten large sweet potatoes can be stored in the warming section 3 (the baking chamber 7 can store only five or six). Since it takes approximately one hour to bake sweet potatoes in the baking chamber 7, the intention is to increase the number of warm sweet potatoes in the warming section 3 in order to increase the number that can be sold during peak demand times (lunchtime, before dinner).

[0056] Door 39 is provided at the front side of heat retention case 32 so as to be able to open and close. Door 39 is also made of transparent resin. An opening and closing knob 39z is provided at the bottom of the front side of door 39. A hinge 39b having a friction locking area is provided at the upper end of door 39. This hinge 39b allows door 39 to rotate up and down around its upper end.

[0057] The friction locking characteristics of hinge 39b will now be explained. In the region between the upper limit of door 39's upward opening and an angle of 50° downward from the upper limit, when the opening / closing knob 39z is released, door 39 is frictionally locked in its current position. Below that, in the rotation range of 120°, door 39 can rotate under its own weight and closes naturally when released. By employing a warming door 39 with such friction locking characteristics (in other words, with an "optional stopper"), baked sweet potatoes can be safely and easily removed from the warming chamber. Furthermore, employing a door in the warming chamber improves the heat retention within the warming section 3 and reduces the drying out of sweet potatoes while they are being kept warm.

[0058] A heat-retaining plate 38 (heat-retaining tray) is provided at the bottom of the case 32 of the heat-retaining section 3 (above the baking chamber 7) so as to cover almost the entire bottom surface. Small pebbles 37 are laid on top of the heat-retaining plate 38. The heat-retaining plate 38 is, for example, a SUS304 plate. The heat-retaining plate 38 has ventilation holes 38d distributed over its entire surface. For example, the ventilation holes 38d are elongated holes measuring 6 mm wide and 50 mm long. The elongated holes prevent the ventilation holes from being blocked by small pebbles placed on top. The small pebbles 37 are similar to the small pebbles 77 of the baking chamber 7. The small pebbles 37 have heat storage properties and also have the effect of preventing a drop in temperature inside the heat-retaining section 3 when the door 39 of the heat-retaining section 3 is opened or closed.

[0059] As shown in Figure 4(B), the baking chamber 7 has ceiling panels 7b and side panels 7b' around the interior 72 (top, back, left and right), and an insulating layer 7g on the outside thereof. A rear panel 7j and an upper panel 7d are attached to the outside of the insulating layer 7g. The outside (rear side) of the rear panel 7j faces the rear panel (decorative side panel) 5b of the casing 5, separated by an air flow path 5f.

[0060] A large number of louvers 5g are formed in the casing rear panel (decorative side panel) 5b. The louvers 5g are generally elliptical, narrowing at the top and opening at the top, and allow air inside and outside the casing 5 to communicate with each other.

[0061] Radiant heat is transmitted from the oven interior 72 to the air flow path 5f, creating a slight negative pressure in the air flow path 5f. Air outside the casing 5 (store atmosphere) flows into this slightly negative pressure air flow path 5f through the louvers 5g, creating an updraft (chimney effect). This heated air flow in the air flow path 5f rises around the inside of the casing side panel (decorative panel) - that is, the outside of the baking oven - and enters the warming section 3 through a passage with the structure described below. This allows residual heat from the baking oven 7 to be used to heat the warming section 3, achieving energy and electricity savings.

[0062] The air flow path 5f also serves the function and effect of cooling (air insulation) the side panels of the casing 5. That is, the rear panel 7j of the baking chamber 7 is at approximately 100°C, but because there is an air current entering through the louvers 5g and flowing through the air flow path 5f, the outer wall (decorative side panel) 5b is cooled to below 40°C. This prevents burns even if a person touches the decorative side panel of the sweet potato roaster.

[0063] The structure and function of the air flow path 5f described here (heated air rising ⇒ heating of the heat retention section 3 and cooling of the decorative side panel) is the same for the left and right side walls of the baking chamber 7 and casing 5, in addition to the side wall at the back side described above (see Figure 2).

[0064] Next, we will explain the configuration in which heated air is introduced into the heat retention section 3 from the side air flow passage 5f on the outside of the baking chamber 7. The route of the heated air introduction is as follows: side air flow passage 5f ⇒ top air flow passage 5j ⇒ burring hole 51d in the heat collection plate 51 ⇒ ventilation hole 38d in the heat retention plate 38 ⇒ small pebbles 37 ⇒ interior 34 of the heat retention section 3.

[0065] The heat collecting plate 51 extends above the top plate 7d of the baking chamber 7 at a certain distance (top air flow path 5j). The rear portion 51j of the heat collecting plate 51 protrudes above the side (rear) air flow path 5f. The end of the rear portion 51j forms a hanging portion 51m that hangs down into the side air flow path 5f. Heated air (hot air) is introduced from the side air flow path 5f into the top air flow path 5j between the rear portion 51j / hanging portion 51m of the heat collecting plate 51 and the side wall 7j / top plate 7d of the baking chamber 7.

[0066] Numerous burring holes 51d are drilled in the portion of the heat collection plate 51 above the baking chamber 7 (most of the underside). The burring holes 51d have a cross section shaped like a tapered truncated cone. An ascending air current toward the heat retention section 3 passes through the burring holes 51d in the heat collection plate 51 (blowing up), concentrating the hot air and sending it into the heat retention section. Example dimensions of the burring holes 51d are a diameter of 9 mm, a pitch of 50 mm, and a burring rise height of 3 mm.

[0067] Above the heat collecting plate 51, a heat insulating plate 38 is arranged opposite to it with a certain gap (air passage 38f) between them. Small pebbles 37 and potatoes P are placed on the heat insulating plate 38. Downward ribs 38h are formed on the four sides of the heat insulating plate 38, increasing the strength and rigidity of the heat insulating plate 38. Wall panels 381 are erected on the outside of the heat insulating plate 38 and surround the heat insulating plate 38 on all four sides.

[0068] The heat insulating plate 38 has a large number of vent holes 38d dispersed therein. Hot air rises through these vent holes 38d. The positions of the vent holes 38d in the heat insulating plate 38 in a plan view are different from the positions of the burring holes 5g in the heat collecting plate 51 in a plan view. The hot air blowing up from the burring holes 5g flows laterally through the air passage 38f and rises through the vent holes 38d in the heat insulating plate 38 (entering the heat insulating section 34). As described above, the vent holes 38d in the heat insulating plate 38 and the burring holes in the heat collecting plate 51 51d The reason why the positions of the air passages 38f and 38c are different in plan view is to cause a mixed flow of air in the air passages 38f and to make the local temperature distribution of the hot air entering the heat retention section 3 uniform.

[0069] The above-described configuration makes it possible to utilize radiant heat from the baking chamber 7 and efficiently divert it to the warming section 3. Specific examples of temperatures in each section are 200°C in the baking chamber and 65°C in the warming section. In other words, the warming section 3 (display space) has an energy-saving structure that utilizes residual heat from the baking chamber 7, eliminating the need for a heater for the warming section 3 and reducing running costs. The 65°C temperature range is also the temperature at which the enzyme β-amylase in baked sweet potatoes is easily activated, which also helps to improve the sweetness of the sweet potato when kept warm.

[0070] Next, the structure of the dust tray 83 and sill holder 85 in the sweet potato roaster 1 of this embodiment will be described with reference to Figures 5 and 6. Figure 5 is a side cross-sectional view of the structure. Figure 6(A) is a perspective view with the dust tray 83 removed, and Figure 6(B) is a perspective view with the sill holder 85 removed.

[0071] The waste receptacle 83 is arranged so as to extend below the tray 80 on which the sweet potatoes P to be roasted are placed and the heating means (sheath heater) 81 (at the bottom of the roasting chamber 7). The waste receptacle 83 can slide forward and backward. Furthermore, the waste receptacle 83 can be removed from the sweet potato roaster 1 when pulled out.

[0072] The waste receptacle 83 has a shallow, box-shaped waste receptacle pan 83f that extends over almost the entire bottom of the baking chamber 7. The pan 83f is made of a flat stainless steel plate with low walls 83h attached to the rear and left and right edges. The front side of the waste receptacle pan 83f is a band-shaped, left-right extending flat band 83c. A knob 83b hangs down from the front end of the flat band 83c, with its lower end projecting diagonally forward.

[0073] The waste pan 83f collects the sweet potato syrup that drips from the sweet potatoes P during baking, as well as burnt potato skins. Sloping eaves 7v protrude downward toward the center of the bottom of the baking chamber 7 from the rear and front of the wall. These sloping eaves 7v guide the sweet potato syrup into the pan 83f. A hollow box beam 7x is positioned on the front upper flat band 83c of the waste pan 83, extending left and right on the front bottom of the baking chamber door 6. This hollow box beam 7x is a sheet metal structure that supports the opening and closing pivot mechanism (hinge 67) of the door 6.

[0074] The trash receptacle 83 rests on the bottom plate 7z of the baking chamber 7, and can be slid forward and backward by manually pushing and pulling the knob 83b. The top surface of the knob 83b is inclined downward toward the front, and also serves to drop the sill hanging from the inner surface of the door 6 into the sill receiver 85. Once pulled out, the trash receptacle 83 can be lifted up and removed from the sweet potato roaster 1.

[0075] The removed garbage tray 83 can be washed in the sink or dishwasher. It is reasonable to wash it about once a day. This allows garbage to be collected all at once, and part-time store staff can easily clean the inside of the store. The honey and garbage that drips from the sweet potato P and sticks to small stones and the heat plate 79 can be cleaned by removing the tray 80. The honey that hits the high-temperature sheath heater is repelled and falls into the garbage tray 83 below.

[0076] The sill receiver 85 is disposed below the baking oven door 6 and receives dew D that adheres to the door and falls. The sill receiver 85 can be freely removed and attached. The door 6 has an insulating layer 62 inside, but because it is designed to be opened and closed, its insulation is inferior to the other walls of the baking oven 7 in terms of airtightness and sealing characteristics. Furthermore, while the door 6 is open, the inside surface of the door 6 is exposed to the air inside the store, causing the temperature to drop. Therefore, moisture in the atmosphere inside the oven 72 (a large amount of water vapor emitted from the sweet potatoes) is likely to condense on the surface of the door 6 (schematically shown as dew D in Figure 5).

[0077] Furthermore, when the door 6 is opened, the atmosphere in the interior 72 blows out from the upper end of the door 6. This atmosphere is cooled by hitting the upper part 5z of the door opening of the casing 5 and the heat protector 41 on the outside of the door opening, and condensation is likely to occur in these areas as well. This condensation drips down and runs down the outer surface of the door 6.

[0078] The side cross section of the sill support 85, as seen in Figure 5, is a shallow channel shape that opens upward. This sill support 85 rests on the front lower part 5x of the casing 5. As seen in Figure 6(B), the four sides of the bottom surface 85f of the sill support 85 are provided with a rear wall 85j, a front wall 85b, and left and right wall sides 85s. Higher end pieces 85p are provided on the left and right ends of the rear wall 85j. Holes 85q are formed in the end pieces 85p, and the sill support 85 can be removed from the sweet potato roaster by hooking them into the holes 85q.

[0079] The collected sill can be disposed of in the sink and washed with water after removing the sill holder 85. This keeps the counter area of ​​stores (convenience stores, etc.) clean and free of stains.

[0080] Next, with reference to Figure 7, the door 6 of the baking chamber 7 of the sweet potato roaster 1 of this embodiment will be described in detail. Figure 7(A) is a side cross-sectional view, and (B) is a perspective view in a fully open state. The door 6 is supported at its lower end by a torque hinge 67, which allows it to be forcibly rotated in a range from closed to half-open but not to rotate under its own weight, and to be able to rotate under its own weight in a range from half-open to fully open. Furthermore, a magnet 69 is provided which attracts and biases the door 6 toward the baking chamber 7 (toward the back) when the door 6 is in an upright closed position.

[0081] As shown in Figure 7(B), door 6 mainly consists of a door frame 65 and an insulating block 63. Insulating block 63 consists of insulating material 62 (shown in a virtual cutaway view) surrounded by a stainless steel box. When the door is closed, insulating block 63 blocks the front of the interior of firing chamber 7.

[0082] The door frame 65 is composed of a front plate 65b that extends across the front of the door and side plates 65g that extend from the left and right edges of the front plate toward the rear. A door opening / closing handle 61 is formed on the upper front side of the front plate 65b so as to protrude toward the front. When the door is closed, the side plates 65g of the door frame 65 overlap the outside of the front side portions 5t of the left and right sides of the sweet potato roaster casing 5.

[0083] The door 6 is connected at its lowest part by torque hinges 67 to the front end surfaces 5s of the left and right sides of the casing 5 so as to be rotatable in the rearward and forward direction. The biasing torque characteristics of the hinges 67 allow the door 6 to be forcibly rotated and unable to rotate under its own weight within the range of the door being closed to half-open (specifically, closed upright 0° to half-open 45°). The door 6 can also be rotated gently under its own weight within the range of half-open to fully-open (specifically, half-open 45° to fully-open 90° (the position in which the door 6 is tilted forward)). In other words, the torque hinges 67 provide a safety mechanism that allows the door to open gently.

[0084] Magnets 69 are attached to the front end surfaces 5s of the left and right sides of the casing 5, above the torque hinges 67. When the door is fully closed, the magnets 69 come into contact with the rear surface (back surface) of a bracket 65d attached to the right end of the door frame 65 and are attracted to it. This magnetic attraction force maintains the fully closed position of the door 6 (increasing the initial force of the opening operation). In other words, it firmly fixes the door in the closed state. The magnetic attraction portion (bracket 65d) is made of magnetic SUS430.

[0085] When opening door 6, the operator pulls handle 61 by hand from the fully closed state to open door 6 slightly. This releases the hot air and steam from inside baking chamber 7 through the upper corners of the chamber. At this time, the operator must keep their face away from door 6. Once the outflow of hot air and steam has stopped, the door can be fully opened. At this time, the door can rotate under its own weight, so no force is required. Note that if there is no torque hinge, pulling the handle by hand will cause door 6 to open fully with force, which would be unpleasant for the operator, as the hot air and steam would hit them. Also, if door 6 were to open with such force that it falls downwards, there is a risk of it hitting or striking a person, which would be inconvenient.

[0086] In rare cases, sweet potatoes may burst while being roasted. If the door 6 opens forcefully at that time, it may hit a person (a store clerk) and cause injury, or the person may drop something they are holding. In the sweet potato roaster 1 of this embodiment, a torque hinge and a magnetic catch prevent the door 6 from opening suddenly, preventing unforeseen incidents.

[0087] Next, the drawer structure of the sweet potato placing tray 80 will be described with reference to Figures 8, 9 and 2. Figure 8 is a side view. Figure 9 is a perspective view for explaining the operation of the drawer structure of the sweet potato placing tray 80. (A) shows the state in which the tray 80 is about to be drawn out with tongs 171 (no sweet potatoes placed on it), and (B) shows the state in which sweet potatoes P are placed on it. Figure 2 is a front view of the entire sweet potato roaster 1 of this embodiment.

[0088] The potato tray 80 is made up of a heat plate 79 and sliders 75 on either side of it. The potato tray 80 slides in the rear-front direction along fixed rails 76 fixed to the left and right walls of the baking chamber 7. The fixed rails 76 are members fixed to the left and right walls of the baking chamber 7 and extend in the rear-front direction. The fixed rails 76 have upper and lower guide rail surfaces 76b and 76f extending in the rear-front direction, as shown by imaginary lines in Figure 8. A fixed roller 76j is fixed to the front end of the fixed rails 76.

[0089] The slider 75 is a horizontally elongated structure extending in the front-to-rear direction, with its lower surface 75g resting on a fixed roller 76j. The slider lower surface 75g moves linearly in the front-to-rear direction on the rotating fixed roller 76j. A rotatable movable roller 75k (FIG. 8) is fixed to the rear end of the slider 75. The roller 75k is guided by guide rail surfaces 76b-76f of the fixed rail 76 and can roll in the front-to-rear direction.

[0090] As shown in Figure 9(A), the sliders 75 are a pair of members that run along the left and right sides of the tray 80. The front ends of the pair of left and right sliders 75 are connected by a front edge member 751. The front edge member 751 is generally L-shaped with a downward bend on the front side. By grasping this downward bent portion with the tip of the tongs 171 and pulling it out, the tray 80 can be pulled out toward the front, above the fully open door 6.

[0091] The above-mentioned rolling structure of the tray 80 drawer allows the tray 80 to be easily pulled out and pushed in. In other words, sweet potatoes can be easily and safely put into and removed from the roasting chamber 72. Furthermore, sweet potato tongs 171 can be used to slide the hot tray 80, so there is no need for a dedicated pull-out tool.

[0092] Next, with reference to Figure 10, we will explain the relationship (one example) between the distribution of hot air rising holes 79k (see Figure 3) on the heat plate 79 and the temperature uniformity inside the oven. The table in the top row of Figure 10 shows the temperature distribution on the top surface of the small marbles 77 (see Figures 1, 2, and 9) inside the oven 72. A to E in the left column (narrow columns) are symbols indicating the positions of the temperature measurement points, and their meanings will be explained below. The second wide column from the left shows the measured temperatures at each point when there is "no unperforated area" (described below). The right-most wide column shows the measured temperatures at each point when there is "unperforated area" (described below).

[0093] The second diagram from the top in Figure 10 is a plan view of the heat plate 79 (equivalent to Figure 3). The diagram on the left is a diagram of "no unperforated area" in which hot air rise holes 79k are opened on the entire surface of the heat plate 79 (except for the peripheral edge). The diagram on the right is a diagram of "with unperforated area" in which hot air rise holes 79k are not opened in the center of the heat plate 79. In each diagram, symbol A indicates the center of the heat plate, and symbols B to E indicate locations near the four corners of the heat plate.

[0094] The photograph at the bottom of Fig. 10 is a perspective view of a state in which small pebbles 77 are placed on a heat plate 79. In the figure, symbols A to E are shown to indicate temperature measurement points.

[0095] Looking at the measured temperature data, in the "no non-perforated area" case on the left side of the table, the temperature of the center A of the heat plate is 236°C, which is significantly higher than the temperatures of the other parts B to E, which are 213°C to 217°C. On the other hand, in the "non-perforated area" case on the right side of the table, the temperature of the center A of the heat plate, 217°C, is not much different from the temperatures of the other parts B to E, which are 211°C to 218°C. Looking at this table, we can see that by not providing a hot air rise hole 79k in the center (central part) of the heat plate (inside the oven), the concentration of hot air blowing up to that part is avoided, and the temperature distribution inside the oven is leveled (uniform). The set temperature inside the oven at the time of temperature measurement was 200°C.

[0096] Users who purchase the sweet potato roaster of the present invention or this embodiment described above will become familiar with how to use it and, by making further adjustments and ingenuity (creations), will be able to roast sweet potatoes of various types and conditions under optimal conditions. ◎Example of creating optimal conditions for roasted sweet potatoes; -Adjusting the far-infrared firing environment (diffuse reflection firing of far-infrared rays) Adjustment of insulation environment and heat retention environment (maintaining a uniform 65℃ environment without heater) - Delicate and accurate temperature control is achieved by utilizing equipment control based on the manufacturer's own designed circuit board (proportional control; current commercially available sweet potato roasters use ON-OFF control).

[0097] ◎Examples of creating ease of use and improving operation · Actual operation of garbage receptacle and sill receptacle · Use of sliding trays The operation panel is operated using a proprietary control board, the first of its kind in the industry for a sweet potato roaster. Menus (temperature control conditions) can be registered based on the number and size of sweet potatoes, and the sweet potato roaster can be customized to suit the store's operating conditions by utilizing power reservation and eco mode.

[0098] ◎ Creating safety ·Low radiation main body casing ·Use of door torque hinges ·Door magnets, etc.

Claims

1. A baking oven (7) for baking sweet potatoes, a tray (80) including a heat plate (79) arranged in the baking chamber and on which sweet potatoes to be baked are placed; Electric heating means (71, 81) for increasing the temperature inside the baking chamber; A sweet potato roaster (1) comprising: The baking chamber (7) includes a sheathed heater (81) as a lower heating means disposed in the lower part of the chamber interior space, the heat plate (79) made of a far-infrared radiative material and having a large number of dispersed hot air rising holes (79k) formed therein and extending over the sheathed heater, and a large number of small pebbles (77) placed on the heat plate; a far-infrared heater (71) as an upper heating means disposed in the upper part of the interior space of the baking chamber (7); moreover, A casing (5) that houses the baking chamber (7); A warming section (3) is provided above the baking chamber to keep the baked sweet potato P warm. An air flow path (5f) is formed between an outer wall (7j) of the baking chamber (7) and an outer wall (5b) of the casing (5), The sweet potato roaster (1) is characterized in that the air in the air flow path (5f) is heated by radiant heat emitted from the outer wall (7j) of the baking chamber and is led to the heat retention section (3).

2. the sheathed heater (81) is arranged along a line that surrounds the center of the interior of the container in a plan view, 2. The sweet potato roaster according to claim 1, wherein the hot air rising holes (79k) of the heat plate (79) are not formed in the center of the interior of the oven in a plan view.

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