Heater unit, reflecting plate and oven

Abstract

The invention provides a heater unit which can uniformly heat a heating cooking utensil at a fixed temperature and is easy to clean. A heater unit (1) is provided with: a sheath heater (11) having a plurality of straight line sections parallel to each other and a semicircular section connecting two straight line sections among the plurality of straight line sections; terminal parts (12) respectively connected to both ends of the sheath heater (11); and a heater housing surrounding both ends and the terminal portion of the sheath heater 11.

Description

Technical Field

[0001] The present invention relates to a heater unit having a sheathed heater, a reflector, and an oven having both the heater unit and the reflector. Background Art

[0002] As a heat source for a heating cooking appliance for cooking food, a gas burner is suitably used. However, for example, in high-rise buildings, from the viewpoint of disaster prevention, there are times when a cooking appliance using electricity as an energy source is desired.

[0003] For example, Patent Document 1 discloses a heating cooking appliance using an electric heater as a heat source. The most common electric heater applied to a heating cooking appliance is a resistance heating type heater that generates heat by passing an electric current through a resistor. In particular, as disclosed in Patent Document 1, for an oven that bakes and cooks food, a sheathed heater in which a heating portion is covered with a metal tubular member is suitably used. A sheathed heater is known as a heater with a low risk of electric leakage or electric shock.

[0004] Moreover, the inventors et al. invented a heating cooking appliance using a cartridge heater and disclosed it in Patent Document 2.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent Laid-Open Publication No. Hei 9-178193

[0008] Patent Document 2: Japanese Patent Laid-Open Publication No. 2021-110509 Summary of the Invention

[0009] [Problems to be Solved by the Invention]

[0010] Compared with a gas burner, a sheathed heater can easily maintain a fixed temperature. In this regard, a heater unit that can heat a heating surface for cooking more uniformly is sought.

[0011] Moreover, if it is a heater used in an oven that bakes and cooks food on a wire mesh, since it will be soiled by oil or the like dripping from the food, it needs to be cleaned regularly. In order to clean the heater efficiently, it is preferable that the heater unit including the heater can be easily detached from and attached to the main body of the oven. On the other hand, the oven equipped with the heater also needs to be cleaned regularly. In this regard, a heater unit and an oven having a structure that is easier to clean are sought.

[0012] The present invention aims to provide a heater unit that can evenly heat a cooking appliance and is easy to clean. The present invention also aims to provide a reflector that can efficiently utilize heat from the heater unit. The present invention also aims to provide an oven equipped with the heater unit and the reflector.

[0013] [Solution to the problem]

[0014] The present invention provides the following aspects of the invention.

[0015] (Item 1)

[0016] A heater unit, characterized by comprising: a sheath heater having a plurality of straight line portions parallel to each other, and a semicircular portion connecting two of the plurality of straight line portions;

[0017] Terminal parts, respectively connected to two ends of the sheath heater; and

[0018] The heater housing surrounds both ends and the terminal portion of the sheath heater.

[0019] (Item 2)

[0020] The heater unit according to Item 1 is characterized in that the sheath heater is formed in a planar shape.

[0021] (Item 3)

[0022] The heater unit according to item 1 or 2 is characterized in that the sheath heater has a circular cross-sectional shape.

[0023] (Item 4)

[0024] The heater unit according to item 1 or 2 is characterized in that the cross-sectional shape of the sheath heater is different between the straight line portion and the semicircular portion.

[0025] (Item 5)

[0026] The heater unit according to item 4 is characterized in that, regarding the cross-sectional shape of the sheath heater,

[0027] The straight line portion is circular,

[0028] The semicircular portion is in a shape similar to a Reuleaux triangle.

[0029] (Item 6)

[0030] The heater unit according to item 1 is characterized in that the heater housing has a rectangular parallelepiped shape,

[0031] An opening for inserting both ends of the sheathed heater is provided in a side wall portion of the heater housing.

[0032] A fireproof board is arranged in contact with the side wall portion provided with the opening.

[0033] (Item 7)

[0034] The heater unit according to Item 6, characterized in that the fireproof board is formed of a gypsum board mixed with pulp.

[0035] (Item 8)

[0036] The heater unit according to Item 1, characterized in that it is grounded.

[0037] (Item 9)

[0038] The heater unit according to Item 8, characterized in that it is provided with a grounding terminal,

[0039] The grounding terminal extends longer to the outside than the terminal portions respectively connected to both ends of the sheathed heater.

[0040] (Item 10)

[0041] A reflector for a roasting oven, characterized in that it is arranged below the sheathed heater, and

[0042] Protrusions and recesses are alternately formed.

[0043] (Item 11)

[0044] The reflector for a roasting oven according to Item 10, characterized in that the position of the protrusion facing the front end of the semi-circular portion of the sheathed heater has a notch,

[0045] The recess is formed so as to extend below the straight portion of the sheathed heater, and both ends or near both ends of the recess have bridging portions, and there are holes between both ends or near both ends.

[0046] (Item 12)

[0047] A roasting oven, characterized in that it includes: a sheathed heater having a plurality of straight portions parallel to each other and a semi-circular portion connecting two of the plurality of straight portions; and

[0048] The reflector for a roasting oven according to Item 10.

[0049] (Item 13)

[0050] A roasting oven, characterized in that it includes: the heater unit according to any one of Items 1 to 9; and

[0051] The reflector for an oven according to item 10 or 11.

[0052] (Item 14)

[0053] The oven according to item 13, further comprising a heater housing covering the heater unit and a heater cover covering at least a part of the upper part of the sheath heater.

[0054] The heater cover has ribs that abut against the side surface of the heater housing.

[0055] (Item 15)

[0056] The oven according to item 13, further comprising a spring that presses the heater housing.

[0057] The spring is grounded.

[0058] [Advantages of the Invention]

[0059] By forming the sheath heater included in the heater unit of the present invention into a shape having a plurality of straight portions parallel to each other and semicircular portions connecting two of the plurality of straight portions, a large area can be uniformly heated by one sheath heater.

[0060] The total length of the sheath heater in the heater unit of the present invention can be adjusted by increasing or decreasing the number of straight portions and semicircular portions of the sheath heater. When the total length of the sheath heater is increased, the number of heater units required for heating can be reduced. By reducing the number of heater units, the operation of removing the heater unit from the oven can be facilitated, and since the number of installation positions of the heater unit is reduced, the trouble of cleaning can be reduced.

[0061] By arranging the reflector of the present invention close to the sheath heater, the heat of the sheath heater can be reflected for efficient heating. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1A is a front view of the heater unit of the embodiment;

[0063] Figure 1B is a top view of the heater unit of the embodiment;

[0064] Figure 1C is a left side view of the heater unit of the embodiment;

[0065] Figure 1D is a right side view of the heater unit of the embodiment;

[0066] Figure 1E is Figure 1B a cross-sectional view taken along line A-A of

[0067] Figure 1F is Figure 1B a sectional view taken along line B-B;

[0068] Figure 1G is Figure 1B a sectional view taken along line C-C;

[0069] Figure 1H of Figure 1H (a) is a sectional view of the straight portion of the sheath heater, Figure 1H (b) is a sectional view of the semi-circular portion of the sheath heater;

[0070] Figure 1I is a perspective view of the heater unit;

[0071] Figure 2 is a perspective view of the heater unit with the upper part of the heater housing removed.

[0072] Figure 3 is a perspective view of the heater unit of a modified example;

[0073] Figure 4 is a perspective view of the heater unit of a modified example;

[0074] Figure 5 is a perspective view of the reflector of the embodiment;

[0075] Figure 6 is a perspective view of the reflector of a modified example;

[0076] Figure 7 is a perspective view of the oven provided on the table board;

[0077] Figure 8 is an assembled perspective view of the oven;

[0078] Figure 9 is an exploded perspective view of the oven;

[0079] Figure 10 is a perspective view of the inside of the oven with the heater unit installed;

[0080] Figure 11 is a perspective view of the heater unit of a modified example with the upper part of the heater housing removed;

[0081] Figure 12 is an assembled perspective view of the connector unit connected to the heater unit of a modified example;

[0082] Figure 13 is a partial enlarged view of the oven having a spring connecting the outer housing and the heater unit;

[0083] Figure 14Is a perspective view of the heater cover of the modified example;

[0084] Figure 15 Is an exploded perspective view of the inside of the oven of the modified example;

[0085] Figure 16 Is a cross-sectional view of the oven equipped with the heater cover of the modified example;

[0086] In the figure, 1, 1A, 1B, 1C are heater units; 2, 2A are reflector plates; 5, 50 are connector units; 7 is a grill; 11, 15, 16 are sheath heaters; 12, 12' are terminal parts; 13, 18 are heater housings; 30 is an inner housing; 40 is an outer housing; 53 is a connector housing; 60 is a spring; 70 is a heater cover; 100, 200, 300 are ovens. Detailed implementation mode

[0087] Hereinafter, the configurations of the heater unit 1, the reflector plate 2, and the oven 100 of the present embodiment will be described with reference to the drawings. The following embodiments are illustrative of the present invention and are not intended to limit the present invention.

[0088] In the following description, the descriptions of relative positions and directions such as "up and down", "left and right", "vertical and horizontal" correspond to the positions and directions on the drawings used for the description. In addition, for clarity, hatching is sometimes omitted in the cross-sectional view.

[0089] [Heater unit]

[0090] The most preferred embodiment of the heater unit 1 will be described in detail. Figure 1A Is a front view of the heater unit of the embodiment. Figure 1B Is a top view of the heater unit of the embodiment. Figure 1C Is a left side view of the heater unit of the embodiment. Figure 1D Is a right side view of the heater unit of the embodiment. Figure 1E Is Figure 1B The A-A line cross-sectional view of. Figure 1F Is Figure 1B The B-B line cross-sectional view of. Figure 1G Is Figure 1B The C-C line cross-sectional view of. Figure 1H (a) is a cross-sectional view of the straight part of the sheath heater, Figure 1H (b) is a cross-sectional view of the semi-circular part of the sheath heater. Figure 1I Is a perspective view of the heater unit. The right side view of the heater unit 1 has the same shape as the left side view. The heater unit 1 has a bilaterally symmetric shape. Moreover, the top view shape and the bottom view shape of the heater unit 1 are the same as Figure 1B The top view shown.

[0091] The heater unit 1 includes a sheathed heater 11, a terminal portion 12, and a heater housing 13. The heater unit 1 of the present invention is suitably applied to a cooking appliance. Among them, it is suitably used for an oven for baking food on a grill.

[0092] As Figure 1H shown, the sheathed heater 11 has a structure in which a linear heating element 112 and an insulating material 113 are arranged in a tubular member 111 made of metal. As the insulating material 113, for example, well-known heat-resistant materials such as MgO (magnesium oxide) powder and BN (boron nitride) powder can be used. The sheathed heater 11 of the present embodiment uses a coil-shaped nickel-chromium alloy wire as the heating element 112.

[0093] The shape of the sheathed heater 11 will be described. As Figure 1B shown, the sheathed heater 11 is a single continuous heater, and a plurality of straight portions and semi-circular portions that are parallel to each other are alternately formed to form a zigzag shape. In the present embodiment, four straight portions 11a, 11b, 11c, 11d and three semi-circular portions 11e, 11f, 11g that are arranged side by side are alternately formed. In other words, one end of two adjacent straight portions 11a and 11b is connected by a semi-circular portion 11e to form a U shape, one end of two adjacent straight portions 11c and 11d is connected by a semi-circular portion 11g to form a U shape, and further, the other ends of the straight portions 11b and 11c are connected by a semi-circular portion 11f.

[0094] As Figures 1A to 1G shown, the sheathed heater 11 is formed in a planar shape. The heating element 112 inside the sheathed heater 11 substantially exists on the same plane.

[0095] In the present embodiment, as Figure 1E , Figure 1G and Figure 1H (a) shown, the cross-sectional shape of most of the straight portions 11a, 11b, 11c, 11d of the sheathed heater 11 is circular. The heating element 112 and the tubular member 111 are arranged in a concentric circle.

[0096] On the other hand, as Figure 1F , Figure 1G and Figure 1H (b) shown, the semi-circular portions 11e, 11f, 11g are in a shape similar to a Reuleaux triangle. More specifically, the semi-circular portions 11e, 11f, 11g have a shape composed of three sides with a straight bottom and two arc-shaped hypotenuses. The straight portions 11a, 11b, 11c, 11d have boundary portions where the surface shape changes smoothly near the semi-circular portions 11e, 11f, 11g. Figure 1IIn this case, regarding the straight portion 11a and the semi-circular portion 11e, the portion with a circular cross-sectional shape is represented by R, the portion with a cross-sectional shape approximating that of a Reuleaux triangle is represented by T, and the boundary portion is represented by S.

[0097] A normal sheath heater is formed into various shapes by bending a linear heater. In the case of a sheath heater with a circular cross-sectional shape, at portions where large bending deformations are made, such as the semi-circular portions 11e, 11f, and 11g, the outer peripheral side of the tubular member expands while the inner peripheral side is compressed. As a result, on the outer peripheral side, the density of the insulating material between the annular member and the heating element decreases, and the insulation performance may deteriorate. Also, during the bending process, the central heating element 112 sometimes shifts more towards the outer side, and the insulation performance may further deteriorate. In contrast, in the sheath heater 11 of the present embodiment, by making the cross-sectional shape of the semi-circular portions 11e, 11f, and 11g approximate that of a Reuleaux triangle, the cross-sectional area of the tubular member 111 is made smaller than that in the case of a circle, and the insulating material 113 is in a compact state, preventing the insulation performance from deteriorating.

[0098] The connection between the sheath heater 11 and the terminal portion 12 will be described. Among the four straight portions 11a, 11b, 11c, and 11d of the sheath heater 11, the two straight portions 11a and 11d arranged on the outer side are formed longer than the two straight portions 11b and 11c arranged on the inner side. The ends of the two straight portions 11a and 11d are bent in a manner that they approach each other. At the end of the straight portion 11a, an end portion 111a connected to the terminal portion 12 is formed. At the end of the straight portion 11d, an end portion 111d connected to the terminal portion 12 is formed.

[0099] Figure 2 A perspective view of the heater unit 1 is shown. The terminal portion 12 includes terminals 12a and 12b connected to the end portions 111a and 111d of the sheath heater 11. Figure 2 In this case, in order to show the arrangement of the end portions 111a and 111d of the sheath heater 11 and the terminals 12a and 12b housed in the heater housing 13, the upper part of the heater housing 13 is removed.

[0100] The heater housing 13 is made of metal, which is a magnetic material such as a ferrite system or a martensitic stainless steel, and has a rectangular parallelepiped shape with a wall portion constituting one bottom surface, four side surfaces, and one upper surface. Hereinafter, among the four side surfaces, the surface into which the end portions 111a and 111d of the sheath heater 11 are inserted is called the front wall 136, the surface opposite to the front wall 136 is called the rear wall 132, and the two side surfaces that are substantially perpendicularly connected to the front wall 136 and the rear wall 132 respectively are called side walls. The heater housing 13 can be formed of separate members for the bottom surface, side surfaces, and upper surface, and each surface can also be formed by a combination of two or more members. Furthermore, it can also be constituted by assembling members including two or more wall portions. In the present embodiment, it is formed by combining a first member constituting the bottom surface and the lower half of the four side surfaces, and a second member constituting the upper surface and the upper half of the four side surfaces, but the constitution of the heater housing 13 is not limited thereto.

[0101] The arrangement of the end portions 111a and 111d of the sheath heater 11 with respect to the heater housing 13 will be described. The end portions 111a and 111d of the sheath heater 11 are inserted into the heater housing 13 through openings provided in the front wall 136. The fixed heating plate 131 is fixed to the front wall 136 by screws, and the end portion 111a is fixed to the fixed heating plate 131. That is, the end portion 111a is fixed to the heater housing 13 via the fixed heating plate 131. On the other hand, the end portion 111d is not fixed to the fixed heating plate 131 but is fixed to the free heating plate 135 disposed inside the heater housing 13. The end portion 111d has a degree of freedom of movement in the front-rear direction inside the heater housing 13, but since the free heating plate 135 functions as a stopper, it will not fall off from the heater housing 13. The constitution that enables the end portion 111d of the sheath heater 11 to move inside the heater housing 13 has the effect of absorbing the deformation when the sheath heater 11 is heated and thermally expanded.

[0102] An insulator is fixed to the rear wall 132 of the heater housing 13. The terminals 12a and 12b of the terminal portion 12 are fixed to the insulator fixed to the rear wall 132. The ends of the terminals 12a and 12b protrude from the insulator.

[0103] If oil or the like dripping from the food material penetrates into the inside of the heater housing 13, it will cause undesirable phenomena such as ignition or deterioration of the terminal portion. To this end, in order to prevent oil or the like from penetrating into the heater housing 13, a fireproof plate 133 is disposed in contact with the front wall 136 of the heater housing 13. The fireproof plate 133 is formed of a gypsum board mixed with pulp.

[0104] Between the members forming the bottom surface, side surfaces, and upper surface of the heater housing 13, a gasket (sealing member) is inserted during assembly, and the spaces between the wall portions are also sealed. The gasket is formed of foamed silicone. In the present embodiment, the gaskets 134a and 134b are respectively disposed between the first member forming the lower half of the side wall and the second member forming the upper half of the side wall. Further, it is preferable that the end portions 111a and 111d of the sheath heater 11 and the front wall 136 and the fireproof board 133 are also sealed by a gasket.

[0105] Inside the heater housing 13, the end portion 111a of the sheath heater 11 and the terminal 12a are connected by a lead wire 14. The end portion 111d of the sheath heater 11 and the terminal 12b are also connected by the lead wire 14. The terminal portion 12 supplies power to the sheath heater 11 by being connected to a power source. The heating element 112 of the sheath heater 11 generates heat using the current supplied from the power source.

[0106] The above is the configuration of the most preferable heater unit 1, but the heater unit 1 can be appropriately deformed according to the size, heating area, and heating amount of the heating and cooking appliance to which it is applied. Hereinafter, modification examples of the sheath heater 11 will be described.

[0107] Figure 3 A heater unit 1A including a sheath heater 15 is shown as a modification example of the heater unit. The cross-sectional shapes of the straight portion and the semicircular portion of the sheath heater 15 of the heater unit 1A are all circular. Other configurations are the same as those of the sheath heater 11, and repeated descriptions are omitted. When the insulation of the sheath heater 15 is sufficiently ensured, the cross-sectional shapes of the straight portion and the semicircular portion can be the same.

[0108] Figure 4 A heater unit 1B including a sheath heater 16 is shown as a modification example of the heater unit. The cross-sectional shapes of the straight portion and the semicircular portion of the sheath heater 16 of the heater unit 1B are all circular, and the straight portion is formed longer than the sheath heater 11. Other configurations are the same as those of the sheath heater 11, and repeated descriptions are omitted.

[0109] The sheath heater of the heater unit, as shown in the heater unit 1B, can change the length of the straight portion. Moreover, the number of the straight portion and the semicircular portion can be increased to have more U-shaped configurations. In this way, by changing the shape of the sheath heater, the heating area can be changed in a timely manner. Even if the shape of the sheath heater is changed, the terminal portion 12 for supplying power can be one, and the attachment and detachment operations for the heating and cooking appliance are very easy.

[0110] Figure 11FIG. 0 shows a modified example of another heater unit, namely a heater unit 1C having a ground terminal. The heater unit 1C includes a sheathed heater 11, a terminal portion 12' including a ground terminal 12c, and a heater housing 18. Figure 11 In FIG., the upper part of the heater housing 18 is removed to show the configuration of the terminal portion 12'. The terminal portion 12' of the heater unit 1C has a total of three terminals. In addition to the terminals 12a and 12b connected to the end portions 111a and 111d of the sheathed heater 11, it is also constituted by a grounded ground terminal 12c. The ground terminal 12c is used to connect to a grounded wiring when heating a cooking appliance.

[0111] The ground terminal 12c is fixed to the heater housing 18 by a fixing fitting, and the ground terminal 12c is electrically connected to the heater housing 18. Moreover, the end portion 111a of the sheathed heater 11 is fixed to a fixed heating plate 131 made of metal, and the fixed heating plate 131 is fixed to the heater housing 18 by screws. Therefore, the sheathed heater 11 is electrically connected to the heater housing 18. When the ground terminal 12c is connected to a grounded wiring, the heater housing 18 and the sheathed portion of the sheathed heater 11 are grounded.

[0112] As Figure 11 shown, the ground terminal 12c is formed longer than the terminals 12a and 12b, and the length protruding from the rear wall of the heater housing 18 is longer than that of the terminals 12a and 12b. By making the ground terminal 12c longer than the terminals 12a and 12b, when the heater unit 1C is installed in a cooking appliance, the heater housing 18 is grounded before the terminals 12a and 12b are connected to the electrical wiring. Similarly, when the heater unit 1C is removed from the cooking appliance, the heater housing 18 remains grounded after the terminals 12a and 12b are disconnected from the electrical wiring. As a result, the heater housing 18 is grounded during the period from installing the heater unit 1C in the cooking appliance to removing it from the cooking appliance. With this structure of the ground terminal 12c, the heater unit 1C eliminates the risk of electric shock even in the case of accidental operation or when the insulation function of the sheathed heater deteriorates due to aging.

[0113] [Reflector]

[0114] Refer to Figure 5 , the most preferred embodiment of the reflector 2 will be described. The reflector 2 of this embodiment is used together with the heater unit 1 to reflect the heat emitted from the sheathed heater 11 to the food side. The reflector 2 is formed of a metal such as stainless steel.

[0115] The reflector 2 has a shape in which convex portions 21 and concave portions 22 are alternately formed. The concave portion 22 is formed by two inclined surfaces that approach each other as they face downward. The heat emitted downward from the sheathed heater 11 is mainly reflected to the food side by the inclined surfaces formed between the convex portion 21 and the concave portion 22. The convex portion 21 is provided between the concave portions 22 and has a flat surface formed at the top.

[0116] In use, the reflector 2 is disposed below the heater unit 1. Therefore, the shape of the reflector 2 corresponds to the shape of the sheathed heater 11 of the heater unit 1. The intervals of the concave portions 22 of the reflector 2 are substantially the same as the intervals of the straight portions 11a, 11b, 11c, 11d of the sheathed heater 11. In use, the concave portions 22 extend below the straight portions 11a, 11b, 11c, 11d of the sheathed heater 11. The flat surface of the convex portion 21 abuts against the lower surface of the front end portions of the semicircular portions 11e, 11f, 11g of the sheathed heater 11 and supports the sheathed heater 11.

[0117] Preferably, a hole 23 is provided at the bottom of the concave portion 22. Bridging portions 24 are provided at or near both ends of the concave portion 22, and both ends of the hole 23 are closed by the bridging portions 24. The hole 23 allows oil and the like dripping from the food during cooking to pass through. Inclined portions 25 that incline downward are provided at the ends of the bridging portions 24, so that stains falling on the reflector 2 fall downward as much as possible.

[0118] Most of the heat of the sheathed heater 11 can be emitted upward by the reflector 2, enabling high-efficiency cooking. Since the reflector 2 has a shape in which convex portions 21 and concave portions 22 are alternately formed, the heat of the sheathed heater 11 is uniformly emitted upward through the inclined surfaces of the concave portions 22. Moreover, as described above, the concave portions 22 extend below the straight portions 11a, 11b, 11c, 11d of the sheathed heater 11, so that the inclined surfaces formed between the convex portion 21 and the concave portion 22 can be close to the straight portions 11a, 11b, 11c, 11d of the sheathed heater 11, and the reflector 2 can efficiently reflect the heat of the sheathed heater 11 to the food side.

[0119] The above is the most preferred embodiment of the reflector 2 used together with the heater unit 1. The reflector can be appropriately deformed according to the shape of the heater unit used together. The following Figure 6 shows a reflector 2A as a modified example and describes its configuration.

[0120] Similar to the reflector 2, the reflector 2A has a shape in which convex portions 21 and concave portions 22 are alternately formed. The difference from the reflector 2 lies in the shape of the convex portion 21. In the convex portion 21 of the reflector 2A, notches 26a, 26b, 26c are provided at positions facing the front ends of the semicircular portions of the sheathed heater.

[0121] In use, the semi-circular portion of the sheathed heater used together with the reflector 2A can enter the notches 26a, 26b, 26c. The sheathed heater is used together with the reflector 2A in a closer state compared to the case of using the reflector 2. The reflector 2A can reflect the heat of the sheathed heater with higher efficiency.

[0122] The reflector 2A may additionally be provided with notches 26a', 26b', 26c', but this is not necessary. The notch 26a' and the notch 26a can be formed at equal distances from the end of the reflector 2A. Similarly, the notch 26b' and the notch 26b can be formed at equal distances from the end of the reflector 2A. The notch 26c' and the notch 26c can be formed at equal distances from the end of the reflector 2A. By providing the further notches 26a', 26b', 26c', the reflector 2A can be arranged in a state of being rotated 180 degrees relative to the sheathed heater, and the user can set it without considering the direction during setting.

[0123] The reflector 2A of the modification does not need to support the semi-circular portion of the sheathed heater, and is particularly suitable for use when combined with a small sheathed heater, for example.

[0124] [Oven]

[0125] Refer to Figures 7 to 10 and the most preferred embodiment of the oven 100 including the heater unit 1 and the reflector 2 will be described. Figure 7 is a perspective view of the oven 100 provided on the tabletop T. The oven of the present embodiment is a cooking appliance that bakes and cooks various foodstuffs such as meat, fish, and vegetables on the grill 7.

[0126] Figure 8 is an assembled perspective view of the oven 100. Figure 9 is an exploded perspective view of the oven 100. Figure 10 is a partially enlarged view of the interior of the oven 100 in a state where the heater unit 1 and the reflector 2 are installed. As Figures 8 to 10 shown, the oven of the present embodiment is an oven with a rectangular heating area.

[0127] As Figure 9 shown, the oven 100 of the present embodiment includes an outer housing 40, a filter 20, an inner housing 30, a reflector 2, a heater unit 1, a grill 7, a top cover 8, a top plate 9, and a control unit (not shown).

[0128] The outer housing 40 is received in the space within the tabletop T. The filter 20 and the inner housing 30 are received within the outer housing 40. The heater unit 1 is detachably fixed within the inner housing 30. The reflector 2 is disposed within the inner housing 30. The top cover 8 and the top plate 9 are disposed on the upper portion of the outer housing 40. The connector unit 5 and the control unit, which are electrically connected to the terminal portion 12 of the heater unit 1, are fixed to the exterior of the outer housing 40.

[0129] The outer housing 40 includes a rectangular bottom wall 41 and four side walls 42A to 42D. An opening penetrating the bottom wall 41 is provided at the center of the bottom wall 41. The filter 20 is disposed in the opening. The filter 20 recovers the oil contained in the smoke generated when baking food ingredients. A pipe D is connected to the lower portion of the outer housing 40, and the smoke generated when baking food ingredients is discharged from the pipe D through the filter 20 by an exhaust device (not shown).

[0130] Support walls 121 for supporting the inner housing 30 and two guide walls 122 are respectively provided on the inner surfaces of the side walls 42A and 42C of the outer housing 40. The inner housing 30 includes a rectangular bottom wall 31 and four side walls 32A to 32D. The inner housing 30 is disposed within the outer housing 40. When using the oven 100, water is filled within the inner housing 30. The oil of the food ingredients flows over the inclined portion 25 of the reflector 2 and falls into the water within the inner housing 30 through the holes 23 and is recovered.

[0131] The top cover 8 is mounted on the upper portions of the side walls 42A to 42D of the outer housing 40. The top plate 9 is placed on the top cover 8. A plurality of through holes 91a are formed in the side wall 91 of the top plate 9, and the smoke generated from the food ingredients during cooking can be absorbed.

[0132] An opening penetrating the side wall 42A of the outer housing 40 is provided to connect the terminal portion 12 of the heater unit 1 and the terminal of the connector unit 5. Moreover, as Figure 9 shown, an opening 32a is formed in the side wall 32A of the inner housing 30 facing the side wall 42A of the outer housing 40. When the inner housing 30 is received within the outer housing 40, the opening of the outer housing communicates with the opening 32a of the inner housing. Facing the communicating openings of the outer housing 40 and the inner housing 30, the connector unit 5 for connecting the heater unit 1 is fixed.

[0133] Refer to Figure 10, a structure for arranging a heater unit 1 and a reflector 2 inside an inner casing 30 will be described. On the inner surface of a side wall 32A of the inner casing 30, a bottom wall 101 for supporting the heater unit 1 and two side walls 102 are provided. The heater unit 1 can be placed on the bottom wall 101. The side walls 102 restrict the heater unit 1 from moving in the horizontal direction. Moreover, step portions 321 are respectively provided on the inner surface of a side wall 32B of the inner casing 30 and on the inner surface of a side wall 32D facing the side wall 32B. The reflector 2 is placed on the step portion 321.

[0134] The connector unit 5 includes a pair of terminals capable of inserting the terminals 12a, 12b of the heater unit 1. Moreover, the connector unit 5 includes a plurality of permanent magnets inside the casing.

[0135] When the connector unit 5 is installed in the outer casing 40, a pair of terminals of the connector unit pass through an opening of the outer casing 40 and an opening 32a of the inner casing 30, and are exposed inside the outer casing 40 and inside the inner casing 30. By inserting the terminal portion 12 of the heater unit 1 into the terminals of the connector unit 5, the heater casing 13 is engaged with the permanent magnets of the connector unit 5, so that the heater unit 1 is connected to the connector unit 5. When the heater casing 13 is placed on the bottom wall 101, the heater unit 1 assumes a horizontal posture.

[0136] In the case of more firmly connecting the heater unit 1 and the connector unit 5, in addition to connecting using permanent magnets, known methods such as additionally providing a buckle or applying pressure using an elastic member can be adopted.

[0137] The oven 100 of the present embodiment includes a separate heater unit 1 as a heating mechanism. The heater unit 1 is detachably connected to the connector unit 5, and the heater unit 1 can be removed from the oven 100, making it easy to clean.

[0138] In the case of installing a heater unit 1C having a ground terminal 12c in the oven, a modified example of a suitable connector unit is shown in Figure 12 . Figure 12 It is a perspective view of a connector unit 5A having a ground terminal 51c. The connector unit 5A has a ground terminal 51c between a pair of terminals 51a, 51b for inserting the terminals 12a, 12b of the heater unit 1. The ground terminal 51c is grounded by being connected to a ground wire on the power supply line by a wiring (not shown). By connecting the ground terminal 12c and the ground terminal 51c, the heater casing 18 is grounded.

[0139] Similar to the connector unit 5, the connector unit 5A includes a plurality of permanent magnets 52 inside the casing. By the permanent magnets 52, the heater casing 18, which is a magnetic material, is fixed to the connector unit 5A.

[0140] Hereinafter, a modified example of an oven having a configuration for grounding a heater unit 1 without a ground terminal will be described with reference to the accompanying drawings. Figure 13 A partially enlarged view of an oven 200 having a spring 60 for grounding the heater unit 1 is shown. The spring 60 is fixed to the side wall of a connector housing 53 mounted on the outer housing 40 by a screw and is arranged on the inner housing 30 side with its front end descending. The spring 60 is formed of a metal material such as SUS304 (stainless steel).

[0141] Before the heater unit 1 is inserted into the connector unit 5, the spring 60 is in a state of being in contact with the upper surface of the heater housing 13 and presses the upper surface of the heater housing 13. By the spring 60 fixed to the connector housing 53 being in contact with the heater housing 13, the connector housing 53 is electrically connected to the heater housing 13. Since the connector housing 53 is electrically connected to the ground wire of a power cord (not shown), the heater housing 13 is also grounded.

[0142] When the heater unit 1 is assembled to the oven 200, before the terminals 12 of the heater unit 1 are connected to the terminals of the connector unit 5, the spring 60 first comes into contact with the upper surface of the heater housing 13, so that the heater housing 13 is grounded. Similarly, when the heater unit 1 is removed from the oven 200, the heater housing 13 remains grounded after the terminals 12a, 12b are separated from the connector unit 5. As a result, the heater housing 13 is always grounded during the period of being assembled to the oven 200. By providing such a spring 60 in the oven 200, even in the case of accidental operation or when the insulation function of the sheathed heater 11 is reduced due to aging deterioration, the risk of electric shock is eliminated.

[0143] Hereinafter, as another modified example of the oven, an oven having a heater cover that covers a part of the heater unit will be described with reference to the accompanying drawings. The heater cover 70 is a member that covers a part of the front wall 136 including the heater housing 13 and a part of the end portions 111a, 111d of the sheathed heater 11.

[0144] The heater cover 70 is arranged for the purpose of preventing stains from adhering to the heater unit 1 and for more effectively connecting the heater unit 1 to the connector unit 5. Figure 14 A perspective view of the heater cover 70 is shown. The heater cover 70 is composed of a cover upper surface 71 having an L-shaped cross section, a pair of opposing cover side surfaces 72a, 72b, and a wall portion of a cover front surface 73, and is open on the side in contact with the heater unit 1. The inner dimensions of the heater cover 70 are approximately the same as the width and height of the heater housing 13.

[0145] Inside the heater cover 70, a substantially rectangular cover-side rib 74 is vertically arranged with respect to the cover front 73. The cover-side rib 74 is composed of cover-side ribs 74a and 74b having the same shape. The upper edges of the cover-side ribs 74a and 74b are respectively fixed to the upper surface 71 of the cover. Notches are formed at the lower parts of the side edges of the cover-side ribs 74a and 74b close to the cover front 73, and a space W (shown in Figure 16 ) is formed at a part of the lower side between the cover-side ribs 74a and 74b and the cover front 73. On the other hand, a tapered surface TA is formed below the side edges of the cover-side ribs 74a and 74b on the side of the heater unit 1 in a manner that the side edges incline inward. By forming the tapered surface TA, the width of the cover-side ribs 74a and 74b becomes narrower downward.

[0146] Figure 15 Fig. shows an exploded perspective view of the inside of the oven 300 assembled with the heater cover 70. An inner housing-side rib 103 is provided on the bottom wall 101 of the inner housing 30. The plate thickness of the inner housing-side rib 103 is approximately the same as the width of the space W between the cover front 73 of the heater cover 70 and the cover-side ribs 74a and 74b. When the heater unit 1 is correctly assembled to the oven 300, the distance between the front wall 136 of the heater unit 1 and the inner housing-side rib 103 is approximately the same as the width of the cover-side ribs 74a and 74b.

[0147] Figure 16 Fig. shows a cross-sectional view of the oven 300 equipped with the heater cover 70.

[0148] The function and effect of the heater cover 70 will be described by explaining the order of assembling the heater unit 1 and the heater cover 70 to the oven 300. The heater unit 1 is inserted along the bottom wall 101 of the inner housing 30 and connected to the connector unit 5. Next, the heater cover 70 is inserted from above the heater unit 1 along the front wall 136 of the heater housing 13 and depressed. The cover-side ribs 74a and 74b are inserted between the heater unit 1 and the inner housing-side rib 103, and the front ends of the cover-side ribs 74a and 74b abut against the bottom wall 101 of the inner housing 30, completing the assembly.

[0149] By providing the tapered surface TA on the side edges of the cover-side ribs 74a and 74b, the heater cover 70 can achieve a firm connection between the heater unit 1 and the connector unit 50. Even when the connection between the heater unit 1 and the connector unit 5 is incomplete and there is not enough space between the heater unit 1 and the inner housing-side rib 103, by forming the tapered surface TA on the cover-side ribs 74a and 74b, while the heater cover 70 is inserted, the side edges of the cover-side ribs 74a and 74b can smoothly squeeze the front wall 136 of the heater unit 1 and move to the correct position. The heater unit 1 is pressed into the heater unit 1 by the pressing of the heater cover 70. After moving to the position where the magnetic force of the permanent magnet of the connector unit 50 reaches, the heater unit 1 is attracted by the permanent magnet and firmly connected to the connector unit 50.

[0150] [Embodiment]

[0151] An embodiment embodying the oven 100 of the present invention will be described.

[0152] The sheath heater 11 has four straight portions and three semi-circular portions, a width of 124 mm, a length of 291 mm, and a diameter of 10 mm for the straight portions. The bottom width of the portion having a cross-sectional shape similar to a Reuleaux triangle of the semi-circular portion is about 10.8 mm, and the height is about 9.1 mm. The thickness of the tubular member 111 of the sheath heater 11 is 0.7 mm.

[0153] Currently, the most widely used sheath heater has a diameter of 5 mm and the thickness of the tubular member 111 is 0.5 mm. In contrast, the sheath heater 11 of the present embodiment is thicker and the tubular member 111 is thicker. Such a configuration has the effect of resisting corrosion caused by gravy, etc., especially when applied to an oven.

[0154] As described above, specific examples of the present invention have been described in detail based on the embodiments and examples, but these are merely illustrative and do not limit the scope of the claims. The technology within the scope of the claims includes various modifications and changes to the specific examples of the above examples. This application also provides the inventions of the aspects disclosed below.

[0155] (Aspect 1) The outer casing, the inner casing, and the grill are not limited to being square, and may be circular or elliptical, for example. The heater unit heats not only a square area but also a circular or elliptical area.

[0156] (Aspect 2) The number of straight portions of the sheath heater 11 may be more than four. Thereby, a wider area can be heated.

Claims

1. A heater unit, characterized in that, The invention comprises: a sheath heater having a plurality of straight line portions parallel to each other and a semicircular portion connecting two of the plurality of straight line portions; and Terminal parts, respectively connected to two ends of the sheath heater; as well as The heater housing surrounds both ends and the terminal portion of the sheath heater.

2. The heater unit according to claim 1, wherein The sheath heater is formed in a planar shape.

3. The heater unit according to claim 2, characterized in that, The cross-sectional shape of the sheath heater is circular.

4. The heater unit according to claim 2, characterized in that, The cross-sectional shape of the sheath heater is different between the straight line portion and the semicircular portion.

5. The heater unit according to claim 4, characterized in that, Regarding the cross-sectional shape of the sheath heater, The straight line portion is circular, The semicircular portion is in a shape similar to a Reuleaux triangle.

6. The heater unit according to claim 1, characterized in that, The heater housing has a rectangular parallelepiped shape, One side wall of the heater housing is provided with openings for inserting both ends of the sheath heater. A fireproof plate is arranged in contact with the side wall portion having the opening.

7. The heater unit according to claim 6, characterized in that, The fireproof board is formed of a gypsum board mixed with paper pulp.

8. The heater unit according to claim 1, wherein Ground.

9. The heater unit according to claim 8, wherein, With ground terminal, The ground terminal extends outward longer than the terminal portions respectively connected to both ends of the sheath heater.

10. A reflector for an oven, characterized in that, It is arranged below the sheath heater and Protrusions and recesses are formed alternately.

11. The reflector for an oven according to claim 10, characterized in that, The convex portion has a notch at a position opposite to the front end of the semicircular portion of the sheath heater. The recessed portion is formed to extend below the straight portion of the sheath heater, has bridge portions at both ends or in the vicinity of both ends, and has a hole between the both ends or in the vicinity of both ends.

12. An oven, characterized in that, The invention comprises: a sheath heater having a plurality of straight line portions parallel to each other and a semicircular portion connecting two of the plurality of straight line portions; and The reflector for an oven according to claim 10.

13. An oven, characterized in that, comprising: the heater unit according to claim 1; and The reflector for an oven according to claim 10.

14. The oven according to claim 13, characterized in that, and further comprising a heater cover covering at least a portion of the heater housing and the upper portion of the sheath heater of the heater unit. The heater cover includes a rib that abuts against a side surface of the heater case.

15. The oven according to claim 13, characterized in that, A spring is further provided to push the heater housing. The spring is grounded.

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