Electromagnetic induced heating conditioner

Abstract

In an electromagnetic induction cooker equipped with a function for weighing the food being heated, the overall strength of the top plate is increased without narrowing the cook's field of view looking down at the control panel through the control window at the front end of the top plate. [Solution] The top plate 2 includes a top plate 67 that constitutes the top surface, and a reinforcing frame 70 made of a rigid material and positioned on the underside of the top plate 67. The top plate 67 is divided into a cooking area 67C and a window area 67W that is continuous with the front side of the cooking area 67C, and the window area 67W includes a transparent operation window 74 that faces the operation unit 16 from above. The reinforcing frame 70 integrally includes a circumferential surrounding frame 85 that follows the periphery of the cooking area 67C, and a pair of reinforcing arms 86 that support both the left and right sides of the operation window 74 in the window area 67W.

Description

Technical Field

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[0001] The present invention relates to a stationary electromagnetic induction cooker installed in a restaurant kitchen or the like.

Background Art

[0002] This type of electromagnetic induction cooker (hereinafter, appropriately referred to as "cooker") is disclosed in, for example, Patent Document 1. The cooker of Patent Document 1 includes a rectangular box-shaped casing with an open top surface, a top plate fixed to close the opening, and a heating unit housed in the casing. The heating unit includes a heating coil located below the top plate, a main board including an inverter circuit that supplies a high-frequency current to the heating coil, and a U-shaped internal frame (mounting member) in a plan view that supports the heating coil. When a cooking container such as a pot containing food ingredients is placed on the top plate and the heating unit is driven to supply a high-frequency current to the heating coil, an induction magnetic field is generated above the top plate, an eddy current flows through the cooking container, and the food ingredients in the cooking container are heated and cooked by the Joule heat generated by the electrical resistance.

[0003] The same type of cooker is also disclosed in Patent Document 2. There, an inclined surface that slopes downward forward is formed on the front surface of the casing, and an operation panel serving as an operation unit such as power supply and output is provided on this inclined surface. The front end portion of the top plate projects horizontally above the operation panel, and the projecting portion is composed of a metal frame formed in a rectangular frame shape and a perspective window made of glass or the like fitted inside thereof. Through this perspective window, a cook standing in front of the cooker can visually recognize and operate the operation panel without bending down backward or bending the body. Further, the projecting portion of the top plate can receive water or the like spilled from the cooking container and prevent water or the like from adhering to the operation panel below.

Prior Art Documents

Patent Documents

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-95781 [Patent Document 2] Japanese Patent Publication No. 2013-242068 [Overview of the project] [Problems that the invention aims to solve]

[0005] The inventors considered incorporating a weighing function for measuring the weight of the food being heated into this type of cooking appliance. Specifically, they considered placing a weighing device at the bottom of the casing, placing a heating unit on top of it, and then placing a top plate on top of that. Similar to the cooking appliance in Patent Document 2, an operating window was provided at the front end of the top plate, allowing access to the casing's operating section from above. In this case, the weighing device is affected by the weight of the heating unit and top plate, and the weight of the food being heated, including the cooking container on the top plate. Since the former weight is constant, by subtracting it beforehand, the latter weight, i.e., the weight of the food being heated, can be measured.

[0006] However, in order to accurately measure the weight of the object being heated, it is essential that the entire weight be applied to the weighing device. For this purpose, the top plate and heating unit must not come into contact with the casing, and therefore, the top plate cannot be fixed to the opening on the top surface of the casing as in conventional methods. While fixing the peripheral edge of the top plate to the casing as in conventional methods ensures the overall strength of the top plate, in this invention, which incorporates a weighing function, it is not possible to fix both together, so the strength of the top plate must be ensured by another means. In particular, at the front end of the top plate, in addition to strength, it is necessary to ensure the visibility of the operation window.

[0007] The objective of the present invention is to increase the overall strength of the top plate in an electromagnetic induction heating cooker equipped with a function for weighing the food being heated, without fixing the top plate to the casing and without narrowing the cook's field of view looking down at the control panel through the control window at the front end of the top plate. [Means for solving the problem]

[0008] The electromagnetic induction heating cooker according to the present invention comprises a top plate 2 on which an object to be heated is placed, a heating unit 3 that supports the top plate 2 from below and heats the object to be heated, a weighing device 4 that supports the heating unit 3 from below and measures the weight of the object to be heated, a casing 1 that houses the heating unit 3 and the weighing device 4, and an operating unit 16 provided at the front of the casing 1. The top plate 2 includes a top plate 67 that constitutes the top surface and a reinforcing frame 70 made of a rigid material and positioned on the underside of the top plate 67. The top plate 67 is divided into a cooking area 67C supported from below by the upper end surface of the heating unit 3 and a window area 67W that is continuous with the front side of the cooking area 67C, and the window area 67W includes a transparent operating window 74 that faces the operating unit 16 from above. Furthermore, the reinforcing frame 70 is characterized by integrally comprising a circumferential surrounding frame 85 that surrounds the heating unit 3 in a plan view and runs along the periphery of the cooking area 67C, and a pair of reinforcing arms 86 that support both the left and right sides of the operation window 74 of the window area 67W.

[0009] The top plate 2 includes a magnetic shield plate 68 positioned between the top plate 67 and the reinforcing frame 70. The magnetic shield plate 68 integrally comprises a plate body 78 sandwiched between the cooking area 67C and the surrounding frame 85, and a pair of left and right support arms 79 sandwiched between the window area 67W and the reinforcing arms 86.

[0010] A bridging section 80, extending to the left and right, is installed between the front ends of a pair of support arms 79 of the magnetic shielding plate 68.

[0011] A reinforcing piece 71 extending parallel to the bridging portion 80 is joined to the lower surface of the bridging portion 80.

[0012] The top plate 67 and the magnetic shield plate 68 are formed in the shape of rectangular plates having the same outer shape in a plan view, and a rectangular outer frame 69 is provided along the four periphery edges of the top plate 67 and the magnetic shield plate 68.

[0013] The casing 1 includes a box-shaped case body 9 having an opening on its top surface, and a rectangular frame-shaped rising wall 13 that rises from the periphery of the opening. The surrounding frame 85 of the reinforcing frame 70 surrounds at least the upper end of the rising wall 13 at intervals.

[0014] The rising wall 13 comprises a front rising wall 96 and a rear rising wall 97 that face each other front and rear, with the heating unit 3 in between. The surrounding frame 85 comprises a front frame 100 that faces the outer surface of the front rising wall 96 of the rising wall 13, and a rear frame 101 that faces the outer surface of the rear rising wall 97 of the rising wall 13. The front overlap amount H1, defined by the vertical distance from the upper end of the front rising wall 96 to the lower end of the front frame 100, is set to be greater than the rear overlap amount H2, defined by the vertical distance from the upper end of the rear rising wall 97 to the lower end of the rear frame 101.

[0015] The front of the upper wall of the case body 9 is an inclined wall 10 that slopes downwards toward the front, and the rear of the upper wall of the case body 9 is a horizontal flat wall 11 that is continuous with the rear end of the inclined wall 10. The front vertical wall 96 of the vertical wall 13 is provided continuously with the inclined wall 10, and the rear vertical wall 97 is provided continuously with the flat wall 11, with the vertical height dimension of the front vertical wall 96 being set to be larger than the vertical height dimension of the rear vertical wall 97.

[0016] A vertical gap is formed between the lower surface of the surrounding frame 85 and the upper wall of the case body 9, allowing a cook to insert their fingers. [Effects of the Invention]

[0017] The electromagnetic induction heating cooker according to the present invention comprises a top plate 2 on which an object to be heated is placed, a heating unit 3 that supports the top plate 2 from below and heats the object to be heated, a weighing device 4 that supports the heating unit 3 from below and measures the weight of the object to be heated, and a casing 1 that houses the heating unit 3 and the weighing device 4. The top plate 2 includes a top plate 67 that forms the top surface and a reinforcing frame 70 made of a rigid material and positioned on the underside of the top plate 67. By positioning the reinforcing frame 70 on the underside of the top plate 67 as in the present invention, the strength of the top plate 67 can be increased without fixing the top plate 2 to the casing 1.

[0018] Specifically, the top plate 67 is divided into a cooking area 67C supported from below by the upper end surface of the heating unit 3, and a window area 67W that is continuous with the front side of the cooking area 67C. The window area 67W includes a transparent operation window 74 that faces the operation unit 16 from above. The reinforcing frame 70 integrally comprises a circumferential surrounding frame 85 that surrounds the heating unit 3 in a plan view and follows the periphery of the cooking area 67C, and a pair of reinforcing arms 86 that support both the left and right sides of the operation window 74 in the window area 67W. With the reinforcing frame 70, which integrally comprises these surrounding frame 85 and reinforcing arms 86, each area 67C and 67W of the top plate 67 can be accurately reinforced, thereby increasing its overall strength. In the cooking area 67C, the periphery, which tends to lack strength, that is, the area outside the part supported by the heating unit 3, can be reinforced by the surrounding frame 85. In the window area 67W, since the reinforcing frame 70 is not placed at the front end of the operation window 74, the strength of the operation window 74 can be ensured by supporting both the left and right sides of the operation window 74 with reinforcing arms 86 without narrowing the view of the cook looking down at the control unit 16 through the operation window 74.

[0019] More specifically, the top plate 2 includes a magnetic shielding plate 68 positioned between the top plate 67 and the reinforcing frame 70. The magnetic shielding plate 68 integrally comprises a plate body 78 sandwiched between the cooking area 67C and the surrounding frame 85, and a pair of left and right support arms 79 sandwiched between the window area 67W and the reinforcing arms 86. With this configuration, the top plate 2 can be further strengthened by forming a laminated section in which the top plate 67, the magnetic shielding plate 68, and the reinforcing frame 70 overlap in three layers vertically at the periphery of the cooking area 67C of the top plate 67 and on both the left and right sides of the operation window 74 of the window area 67W.

[0020] By installing a bridging section 80 that extends left and right between the front ends of a pair of support arms 79 of the magnetic shield plate 68, the strength of the pair of support arms 79 and, consequently, the strength of the front part of the top plate 67 can be further increased.

[0021] By joining a reinforcing piece 71 parallel to the lower surface of the bridging section 80, the bridging section 80 can be made substantially thicker vertically, thereby maintaining its strength while making it thinner front to back, and thus minimizing the narrowing of the cook's field of view as they look down at the operating section 16 through the operating window 74.

[0022] If the top plate 67 and the magnetic shield plate 68 are formed as rectangular plates having the same outer shape in a plan view, the periphery of the top plate 67 can be supported from below by the magnetic shield plate 68, thereby increasing the strength of the periphery. Furthermore, if a rectangular outer frame 69 is provided along the four peripheries of the top plate 67 and the magnetic shield plate 68, the four peripheries can be protected from impact by cooking containers P that the cook brings onto the top plate 2.

[0023] The casing 1 includes a box-shaped case body 9 having an opening on the upper surface, and a square frame-shaped rising wall 13 rising from the periphery of the opening. According to this rising wall 13, even if water (liquid) such as spillage from the cooking container P splashes on the upper surface of the case body 9, it is possible to effectively prevent the water from entering the casing 1 through the opening on the upper surface. Further, when the surrounding frame 85 of the reinforcing frame 70 provided on the top plate 2 surrounds at least the upper end portion of the rising wall 13 with a space therebetween, it is possible to regulate by the surrounding frame 85 that water directly splashes on the upper end portion. Even if water splashes on the lower portion of the rising wall 13, the water cannot enter the casing 1 unless it climbs along the outer surface of the rising wall 13, and its entry is extremely difficult. According to these rising wall 13 and surrounding frame 85, a trap-shaped waterproof structure can be formed around the opening on the upper surface of the casing 1, and the entry of water from the opening can be accurately prevented.

[0024] The front-side overlapping amount H1 defined by the vertical distance from the upper end of the front wall 96 of the rising wall 13 to the lower end of the front frame 100 of the surrounding frame 85 can be set larger than the back-side overlapping amount H2 defined by the vertical distance from the upper end of the rear wall 97 of the rising wall 13 to the lower end of the rear frame 101 of the surrounding frame 85. For example, when water spills from the cooking container P during the process of a cook carrying the cooking container P onto the top plate 2, the water is mainly exposed to the front side of the cooker facing the cook. Thus, since the front side of the cooker has more opportunities to get wet with water than the back side, if the front-side overlapping amount H1 is set larger as described above, it is possible to more accurately prevent the entry of water into the casing 1.

[0025] If the front part of the upper wall of the case body 9 is made into an inclined wall 10 that slopes downward forward, water adhering to the upper wall of the case body 9 can be made to flow downward forward on the front side of the cooker, where there are relatively many opportunities of getting wet, thereby preventing the retention of the water. Further, if the front vertical wall 96 of the upright wall 13 is provided continuously with the inclined wall 10 and, on the other hand, the rear vertical wall 97 of the upright wall 13 is provided continuously with the flat wall 11 on the rear side of the inclined wall 10, the vertical height dimension of the front vertical wall 96 can be set larger than the vertical height dimension of the rear vertical wall 97 without increasing the overall vertical height of the casing 1 unnecessarily. By forming the front vertical wall 96 of the upright wall 13 high in this way, it is possible to more accurately prevent water from entering into the casing 1 on the front side of the cooker, where there are relatively many opportunities of getting wet.

[0026] If a vertical gap through which a cook can insert a finger is formed between the lower surface of the surrounding frame 85 and the upper wall of the case body 9, even when splashing from the cooking container P reaches the lower end portion of the upright wall 13, the cook can easily wipe it off with a cloth or the like.

Brief Description of the Drawings

[0027] [Figure 1] It is a perspective view of an electromagnetic induction heating cooker according to an embodiment of the present invention. [Figure 2] It is a longitudinal side view of the electromagnetic induction heating cooker. [Figure 3] It is a longitudinal front view of the electromagnetic induction heating cooker. [Figure 4] It is a front view of the electromagnetic induction heating cooker. [Figure 5] It is a side view of the electromagnetic induction heating cooker with the top plate separated. [Figure 6] It is a longitudinal side view of the front end portion of the electromagnetic induction heating cooker. [Figure 7] It is a longitudinal side view of the rear end portion of the electromagnetic induction heating cooker. [Figure 8] It is a longitudinal front view of the side end portion of the electromagnetic induction heating cooker. [Figure 9] It is a plan view of the electromagnetic induction heating cooker with a part of the top plate of the top plate broken. [Figure 10] This is a magnified view of the central part of the heating coil in Figure 9. [Figure 11] This is a disassembled perspective view of the top plate. [Modes for carrying out the invention]

[0028] (Embodiment) Figures 1 to 11 show an embodiment of the electromagnetic induction heating cooker according to the present invention (hereinafter referred to as "cooker" as appropriate). In this embodiment, front, back, left, right, and up and down refer to the intersecting arrows shown in Figure 1 and the front, back, left, right, and up and down indications written near each arrow. As shown in Figures 2 and 3, the cooker consists of a top plate 2 on which the food to be heated is placed, a heating unit 3 that supports the top plate 2 from below and heats the food to be heated, a weighing device 4 that supports the heating unit 3 from below and measures the weight of the food to be heated, and a casing 1 that houses the heating unit 3 and the weighing device 4. The casing 1 is made of a metal such as stainless steel and prevents leakage of magnetism and electromagnetic waves generated from the heating unit 3.

[0029] The weighing device 4 is positioned at the bottom of the casing 1, slightly towards the rear of its center. The heating unit 3 is fixed on top of the weighing device 4 within the casing 1 and is not in contact with the casing 1. The top plate 2 is fixed on the upper end of the heating unit 3 and is also not in contact with the casing 1. By keeping the top plate 2 and heating unit 3 in contact with the casing 1 in this way, the entire weight of the object to be heated on the top plate 2 (including cooking containers P such as pots) is applied to the weighing device 4 via the top plate 2 and heating unit 3, allowing for accurate measurement of the object's weight. The weighing device 4 is affected by the weight of the top plate 2 and heating unit 3, as well as the weight of the object to be heated on the top plate 2. Since the former weight is constant, it can be subtracted beforehand to measure the latter, i.e., the weight of the object to be heated.

[0030] In front of the heating unit 3 and the measuring device 4, specifically in the front part of the casing 1, are housed a control unit 5 responsible for controlling the cooker and a cooling fan 6 for air-cooling the heating unit 3 and other components. These heating unit 3, measuring device 4, control unit 5, and cooling fan 6 are connected by power cables and communication cables (not shown). The control unit 5 and cooling fan 6 are driven by DC voltage, and the heating unit 3 is equipped with a converter that converts AC commercial power to DC. In other words, the AC voltage supplied from the commercial power supply is converted to DC voltage by the converter on the heating unit 3, and then supplied from the converter to the control unit 5 and cooling fan 6 via power cables.

[0031] As shown in Figures 1 and 4, the casing 1 is constructed using a flat, roughly rectangular box-shaped case body 9 as its base, with a smaller vertical dimension compared to its front-to-back and left-to-right dimensions. The majority of the front half of the upper wall of the case body 9 is an inclined wall 10 that slopes gently downwards toward the front, and the area behind the rear end of the inclined wall 10 is a horizontal flat wall 11. A square-shaped opening is provided in plan view from the front-to-back center of the inclined wall 10 to near the rear end of the flat wall 11, and a rectangular frame-shaped rising wall 13 is formed rising from the four periphery of this opening. The rising wall 13 is positioned in the left-to-right center of the upper wall of the case body 9. As shown in Figure 5, in the front part of the rising wall 13, i.e., the part continuous with the inclined wall 10, the rising wall 13 is formed to be longer in the vertical direction as it approaches the front end, and the height position of the upper end of the rising wall 13 is the same around its entire circumference.

[0032] As shown in Figure 6, an operating space S is formed between the front end of the inclined wall 10 of the case body 9 and the front end of the top plate 2 located above it, allowing a cook standing in front of the cooking appliance to insert their hand. An operating section 16 facing the operating space S is provided at the front end of the inclined wall 10. As shown in Figure 1, the operating section 16 consists of a touch panel 17 positioned in the center, a push-type switch button 18 positioned to the left of the touch panel 17, and a rotary dial 19 positioned to the right of the touch panel 17. Although not shown, a power switch for the cooking appliance, which is pressed via the switch button 18, is located inside (below) the switch button 18, and an encoder board for detecting the amount of rotation of the dial 19 by the cook is located inside (below) the dial 19. The inclined wall 10, including the operating section 16, slopes gently downwards, specifically at an angle of 12°, so that a cook standing in front of the cooking appliance can face the operating section 16 without bending down. This inclination angle is preferably set to less than 45°, more preferably less than 30°, and even more preferably less than 15°.

[0033] The touch panel 17 displays the operating status of the cooking appliance and accepts touch operations from the cook. As shown in Figure 6, the touch panel 17 is supported from below by a support frame 21 located on the inner (lower) side of the inclined wall 10, and the upper surface of the touch panel 17 is exposed to the outside through a rectangular panel opening 22 made in the inclined wall 10. A main circuit board 23 that controls the entire cooking appliance is fixed to the lower side of the support frame 21, and these support frame 21, main circuit board 23 and touch panel 17 are integrated as a control unit 5. An emergency stop button 24 is provided at the lower end of the front of the case body 9, which is pressed in emergencies such as when the cooking container P overheats. When this emergency stop button 24 is pressed, the main circuit board 23 immediately stops the heating unit 3.

[0034] A vertically extending air supply duct 26 is provided between the control unit 5 and the heating unit 3, and a pair of axial-flow type cooling fans 6 are housed at the lower end of this air supply duct 26. The lower end of the air supply duct 26 faces an air intake port 27 opened at the front of the bottom wall of the case body 9, and a dust collection filter 29 with an integrated handle 28 is installed on the inner (upper) side of this air intake port 27. The filter 29 is installed so as to be easily inserted and removed in the front-to-back direction through horizontally elongated slits 30 opened at the corners between the front wall and the bottom wall of the case body 9.

[0035] The rear wall of the supply duct 26 is in close proximity to the front of the heating unit 3 and the metering device 4, with a gap in between. A first outlet 31 facing the top of the heating unit 3 is provided at the upper end of the rear wall, and a second outlet 32 ​​facing the bottom of the heating unit 3 is provided below it. The front wall of the supply duct 26 is provided with an inclined section that is approximately parallel to the inclined wall 10 of the case body 9, and a third outlet 33 facing the bottom of the control unit 5 is provided in this inclined section. The cooling fan 6 forms an upward airflow inside the supply duct 26, and the cooling air taken into the supply duct 26 from the air intake 27 is blown out rearward from the first outlet 31 and the second outlet 32 ​​to air cool the heating unit 3, and at the same time blown out diagonally upward from the third outlet 33 to air cool the control unit 5.

[0036] As shown in Figure 3, the heating unit 3 consists of a heating coil 36 facing the inner surface of the top plate 2, an inverter board 37 that supplies high-frequency current to the heating coil 36, and a housing 38 that houses the heating coil 36 and the inverter board 37. The heating coil 36 is made by winding a litz wire, which is made by twisting together many strands of wire, in a spiral shape. The litz wire is formed by a primary twist, which twists the strands together, and a secondary twist, which twists together bundles of primary twists. A pair of ends of the heating coil 36 are electrically connected to the inverter board 37. When a high-frequency current is supplied from the inverter board 37 to the heating coil 36, an induced magnetic field is generated on the upper side of the top plate 2, causing eddy currents to flow in the cooking container P on the top plate 2. The Joule heat generated by the electrical resistance of these eddy currents heats the cooking container P and the food to be heated contained within it.

[0037] The housing 38 is made of a metal such as stainless steel and is formed in a roughly channel shape mainly consisting of a pair of vertical side walls 40 and a horizontal bottom wall 41, with the top and front and rear surfaces of the housing 38 being open. The bottom wall 41, which connects the lower ends of the side walls 40, is placed on the top surface of the weighing device 4, and a pair of connecting pieces 42 that extend downward in a continuous manner from the front and rear ends of the bottom wall 41 are joined to the front or rear surface of the weighing device 4 (see Figure 2).

[0038] The inverter board 37 is supported on the upper surface of the lower wall 41, and a heat sink 44 for heat dissipation is provided on the upper surface of the inverter board 37. These inverter board 37 and heat sink 44 face the second outlet 32 ​​of the supply duct 26 described earlier through an opening on the front of the housing 38, and are therefore cooled by the air blown out from the second outlet 32. The air that has cooled these components through heat exchange is discharged outside the cooker through an exhaust port 46 opened in the rear wall 45 of the casing 1 via an opening on the rear of the housing 38 (see Figure 7). The rear of the case body 9 of the casing 1 is open, and the rear wall 45 is detachably attached to the case body 9 so as to close this opening.

[0039] As shown in Figure 3, the opening on the top surface of the housing 38 is closed by a roughly rectangular dish-shaped top cover 49 that supports the coil unit 48, including the heating coil 36. The top cover 49 is formed in an inverted hat shape with openings on the front, rear and top surfaces, and flange portions 50 provided on both the left and right ends of the top cover 49 are supported at the upper end of the housing 38. As shown in Figure 8, support pieces 51 are formed inwardly at the upper end of each side wall 40 of the housing 38 to support the flange portions 50 of the top cover 40 from below. In addition, elongated connecting pieces 52, used for connecting to the top plate 2 as will be described later, are formed inwardly at the rear end of each side wall 40.

[0040] As shown in Figure 3, the coil unit 48 consists of a horizontal disc-shaped heating coil 36 with an open center, a plurality of rectangular ferrite rods 55 arranged along the lower surface of the heating coil 36, and a horizontal disc-shaped coil base 56 that supports the heating coil 36 and the ferrite rods 55. As shown in Figure 9, the ferrite rods 55 are arranged to radiate outwards from the central axis of the heating coil 36. Specifically, eight ferrite rods 55 are arranged at equal intervals in the circumferential direction on the inner circumference near the inner edge of the heating coil 36, and sixteen ferrite rods 55 are arranged at equal intervals in the circumferential direction on the outer circumference near the outer edge of the heating coil 36. By placing the highly permeable ferrite rods 55 on the lower surface of the heating coil 36, the magnetic flux emitted downward by the heating coil 36 flows through the ferrite rods 55, significantly reducing the magnetic flux leaking downward from the coil unit 48. In addition, the top cover 49 that supports the coil unit 48 is made of aluminum, a non-magnetic metal, and this top cover 49 also exhibits magnetic shielding, suppressing downward magnetic flux leakage.

[0041] The coil base 56 is placed on a horizontal base wall 58 that forms the bottom surface of the top cover 49. Four fastening seats 59 are arranged in a series on the outer circumference of the coil base 56, extending radially toward the four corners of the base wall 58, and each fastening seat 59 is fastened and fixed to the base wall 58. As shown in Figure 10, a cylindrical sensor cylinder wall 60 is provided in the center of the coil base 56, extending vertically along the inner circumference of the heating coil 36. Two temperature sensors 61 and 62 and a thermal fuse 63 are arranged in the space surrounded by this sensor cylinder wall 60. The thermal fuse 63 cuts off the current flowing to the heating coil 36 when it detects overheating of the heating coil 36 due to overcurrent. In the space within the sensor cylinder wall 60, the magnetic flux emitted by the heating coil 36 cancels each other out, so the adverse effects of the magnetic flux on the temperature sensors 61 and 62 can be reduced.

[0042] The first temperature sensor 61 is a thermistor that is in close contact with the underside of the top plate 67 of the top plate 2 and detects its temperature, and is biased upward by a spring (not shown) assembled inside the sensor cylinder wall 60. As shown in Figure 2, the second temperature sensor 62 is a radiation thermometer that detects the temperature of infrared radiation emitted from the bottom of the cooking container P, and is formed in a vertically elongated cylindrical shape and is assembled in the center of the base wall 58. The upper end of the second temperature sensor 62, located inside the sensor cylinder wall 60, is positioned away from the top plate 67 and below the ferrite 55, thereby preventing the second temperature sensor 62 from being heated by the magnetic flux of the heating coil 36. The remaining part of the second temperature sensor 62, excluding the upper end, protrudes downward from the center of the base wall 58 and is surrounded by a rectangular cylindrical sensor case 64 assembled on the underside of the base wall 58. The sensor case 64, like the base wall 58, is made of aluminum, a non-magnetic metal, and protects the second temperature sensor 62 from electromagnetic noise emitted by the inverter board 37. The entire thermal fuse 63 is supported by a sensor case 64, and its temperature-sensing element faces the heating coil 36 via the sensor cylinder wall 60.

[0043] The first outlet 31 of the supply duct 26 faces the top of the heating unit 3 from the front. The front end of the base wall 58 of the top cover 49 is located immediately behind the upper and lower midpoint of this first outlet 31, and therefore the air blown into the heating unit 3 from the first outlet 31 is divided into the upper and lower sides of the base wall 58. The air flowing on the lower side of the base wall 58 cools the second temperature sensor 62 and other components, and then is discharged outside the cooker through the exhaust port 46 on the rear wall 45 of the casing 1 via an opening on the rear of the housing 38. The air flowing on the upper side of the base wall 58 cools the coil unit 48 and the top plate 67 of the top plate 2, and then is discharged outside the cooker through the upper and lower gap mainly between the top plate 2 and the rear of the casing 1.

[0044] As shown in Figure 11, the top plate 2 comprises a rectangular top plate 67 made of heat-resistant glass, a rectangular magnetic shield plate 68 positioned on the underside of the top plate 67, a rectangular outer frame 69 surrounding the four edges of the top plate 67 and the magnetic shield plate 68, and a reinforcing frame 70 and reinforcing piece 71 joined to the underside of the magnetic shield plate 68. These components are integrated as a single unit.

[0045] The top plate 67, which forms the top surface of the top plate 2, is formed in the shape of a vertically elongated rectangular plate, with its front-to-back dimensions being larger than its left-to-right dimensions. The underside of the top plate 67 is painted, except for the circular coil window 73 and the trapezoidal operation window 74, for the purpose of concealing the inside of the cooker. The coil window 73 is positioned offset to the rear from the center of the top plate 67 and faces the heating coil 36 from above. The majority of the rear portion of the top plate 67, centered on the coil window 73, constitutes a cooking area 67C that supports the cooking container P containing the food to be heated. The operation window 74 is positioned at the front end of the top plate 67 and faces the operation unit 16 from above. The front end portion of the top plate 67, including the operation window 74, constitutes a window area 67W that allows the operation unit 16 to pass upward and protects against water spilled from the cooking container P. A cook standing in front of the cooking appliance can adjust the output of the heating coil 36 of the heating unit 3 by operating the control unit 16 while viewing the entire control unit 16 through the control window 74.

[0046] The magnetic shield plate 68 is made of a non-magnetic conductive material such as aluminum or copper, and is formed in the shape of a vertically elongated rectangular plate having the same front-to-back and left-to-right dimensions as the top plate 67. Slightly behind the center of the magnetic shield plate 68, a circular coil opening 75 is provided to allow the heating coil 36 to face the coil window 73 of the top plate 67, and a trapezoidal operation opening 76 is provided at the front end of the magnetic shield plate 68 to allow the operation section 16 to face the operation window 74 of the top plate 67. The diameter of the coil opening 75 is set to be slightly larger than the outer diameter of the heating coil 36.

[0047] The magnetic shield plate 68 integrally comprises a rectangular ring-shaped plate body 78 that demarcates the coil opening 75, a pair of support arms 79 that extend forward continuously from both the left and right ends of the front edge of the plate body 78, and a bridging section 80 installed between the front ends of the support arms 79. The pair of support arms 79 and the bridging section 80 together with the front edge of the plate body 78 demarcate the operation opening 76. The plate body 78 supports the coil window 73 in the cooking area 67C of the top plate 67 from below all around, and the pair of support arms 79 support both the left and right sides of the operation window 74 in the window area 67W of the top plate 67 from below. The aforementioned reinforcing pieces 71 that constitute the top plate 2 are adhesively fixed to the lower surface of the bridging section 80 that extends to the left and right. The reinforcing pieces 71 are arranged parallel to the bridging section 80 and along the inner surface of the front edge of the outer peripheral frame 69 (see Figure 6).

[0048] The magnetic shield plate 68 in this embodiment suppresses magnetic leakage to the surrounding area of ​​the cooking container P on the top plate 2, supports and reinforces the top plate 67 from below, and also serves as a means of connecting the top plate 2 to the heating unit 3. Specifically, a pair of left and right first connecting pieces 81 are formed on the front half of the plate body 78, and a pair of left and right second connecting pieces 82 are formed on the rear half of the plate body 78, both cut and bent toward the lower surface. These four connecting pieces 81 and 82 are connected to the housing 38 of the heating unit 3, as will be described later.

[0049] The reinforcing frame 70, which is joined to the lower surface of the magnetic shielding plate 68, is made of a resin molded product with a vertical thickness sufficiently larger than that of the magnetic shielding plate 68 and the top plate 67, and integrally comprises a surrounding frame 85 that is roughly square in shape in plan view, and a pair of left and right reinforcing arms 86 that extend forward from both front corners of the surrounding frame 85. The surrounding frame 85 is positioned along the outer edge of the plate body 78 of the magnetic shielding plate 68, and supports and reinforces the plate body 78 and the cooking area 67C of the top plate 67 from below. Each reinforcing arm 86 is formed in the same shape as the support arm 79 of the magnetic shielding plate 68 in plan view, and is joined to the entire lower surface of the support arm 79, and supports and reinforces the support arm 79 and the window area 67W of the top plate 67 from below. Note that the material of the reinforcing frame 70 is not limited to synthetic resin, but can be made of any material with high rigidity such as metal.

[0050] The surrounding frame 85 surrounds the four connecting pieces 81 and 82 provided on the plate body 78 of the magnetic shield plate 68. As shown in Figure 5, the front pair of first connecting pieces 81, which have a relatively small vertical dimension, are located entirely within the space enclosed by the surrounding frame 85, while the rear pair of second connecting pieces 82, which have a relatively large vertical dimension, have their lower halves protruding downward from the space.

[0051] The first connecting piece 81 is connected to the outer surface of the side wall 40 of the housing 38 of the heating unit 3. Specifically, each first connecting piece 81 is formed in the shape of a vertical rectangular plate with the left-right direction as the thickness direction, and an engagement groove 88 opening forward is cut out at its front edge. Correspondingly, an engagement pin 89 is provided protruding from the outer surface of the upper end of each side wall 40, near the front end, which can enter and engage with the engagement groove 88.

[0052] The second connecting piece 82 is connected to the aforementioned connecting piece 52, which is continuous with the rear end of the side wall 40. More specifically, each second connecting piece 82 is formed in an L-shape in plan view by a first piece portion 91 and a second piece portion 92 which are perpendicular to each other. The first piece portion 91, which is continuous with the plate body 78 of the magnetic shield plate 68, is formed in a trapezoidal plate shape located on the same plane as the first connecting piece 81, and the second piece portion 92 is provided continuous with the rear edge of the first piece portion 91, which is the longer of the two sides. The second piece portion 92 is formed in a vertically elongated rectangular plate shape with the front-to-back direction as the thickness direction, and the lower end of this second piece portion 92 is fastened and fixed to the rear side of the connecting piece 52 with a screw 93.

[0053] The upper end of the heating unit 3, including the heating coil 36, protrudes upward from an opening at the upper end of the rising wall 13 of the casing 1. To connect the top plate 2 to this heating unit 3, first the plate body 78 of the magnetic shield plate 68 of the top plate 2 is placed on the upper end surface of the heating unit 3 (more specifically, the upper surfaces of the left and right flange portions 50 of the upper cover 49 that supports the coil unit 48). At this stage, the entire top plate 2 is placed further back than the actual connection position so that each first connecting piece 81 of the top plate 2 does not touch the engagement pin 89 of the heating unit 3. At this time, each second connecting piece 82 of the top plate 2 is inserted into the gap between the heating unit 3 (housing 38) and the casing 1 (rising wall 13).

[0054] Next, the worker responsible for connecting the top plate 2 pulls the entire top plate 2 towards the front along the upper end surface (upper surface of the flange portion 50) of the heating unit 3. This causes each engaging pin 89 to enter and engage with the engaging groove 88 of the first connecting piece 81, and at the same time, the second piece 92 of each second connecting piece 82 is received by the rear surface of the connecting piece 52 of the housing 38 (see Figure 7). Finally, the lower end of each second piece 92 is fastened and secured to the connecting piece 52 with screws 93, completing the connection of the top plate 2 to the heating unit 3. Since the lower end of each second piece 92 faces the inner surface of the rear wall 45 of the casing 1, the worker can remove the rear wall 45 from the case body 9, access the lower end of each second piece 92 through the opening on the rear of the case body 9, and screw in the screws 93 from the rear side. Note that when performing maintenance on the cooker, the top plate 2 can be separated from the heating unit 3 by following the reverse procedure described above.

[0055] As shown in Figure 5, the vertical wall 13 of the casing 1 is formed in a rectangular frame shape, and specifically consists of a front vertical wall 96 that forms the front edge, a rear vertical wall 97 that forms the rear edge, and a pair of side vertical walls 98 that form the left and right edges. The vertical height dimension of the front vertical wall 96 that is continuous with the inclined wall 10 of the case body 9 is set to be larger than the vertical height dimension of the rear vertical wall 97 that is continuous with the flat wall 11, so that the height position of the upper end of the vertical wall 13 is the same around its entire circumference. The vertical height dimensions of the left and right side vertical walls 98 are uniform in the rear half that is continuous with the flat wall 11, and in the front half that is continuous with the inclined wall 10, they are set to be larger as they approach the front end.

[0056] Furthermore, the surrounding frame 85 on the underside of the top plate 2 is also formed in a rectangular frame shape that is slightly larger than the vertical wall 13 in a plan view. Specifically, it consists of a front frame 100 that forms the front edge, a rear frame 101 that forms the rear edge, and a pair of side frames 102 that form the left and right edges. The vertical height dimension of the front frame 100 (the dimension of projection from the underside of the plate body 78 of the magnetic shield plate 68) is set to be larger than the vertical height dimension of the rear frame 101, and this dimensional difference is approximately equal to the difference in vertical height dimensions between the front vertical wall 96 and the rear vertical wall 97. The vertical height dimensions of the left and right side frames 102 are uniform in their rear half, and are set to be larger as they approach the front end in their front half. The underside of the rear half of each side frame 102 is horizontal, that is, parallel to the top surface of the flat wall 11 of the case body 9, and the underside of the front half of each side frame 102 slopes downward parallel to the top surface of the inclined wall 10 of the case body 9.

[0057] As shown in Figure 2, when the top plate 2 is connected to the heating unit 3, the surrounding frame 85 surrounds at least the upper end of the rising wall 13 with a gap. Specifically, the front frame 100 of the surrounding frame 85 faces the outer surface of the front rising wall 96 of the rising wall 13 with a gap, the rear frame 101 of the surrounding frame 85 faces the outer surface of the rear rising wall 97 of the rising wall 13 with a gap, and each side frame 102 of the surrounding frame 85 faces the outer surface of the side rising walls 98 of the rising wall 13 with a gap. The rear frame 101 covers only the upper end of the rear rising wall 97 from the outside (rear), while the front frame 100 covers the upper majority of the front rising wall 96 from the outside (front). In other words, the front overlap amount H1, defined by the vertical distance from the top of the front wall 96 to the bottom of the front frame 100, is set to be sufficiently larger than the rear overlap amount H2, defined by the vertical distance from the top of the rear wall 97 to the bottom of the rear frame 101. The side overlap amount, defined by the vertical distance from the top of the side wall 98 to the bottom of the side frame 102, is equal to the rear overlap amount H2 in the rear section where the vertical height dimensions of the side wall 98 and the side frame 102 are uniform. On the other hand, in the front section where the vertical height dimensions of the side wall 98 and the side frame 102 increase as they approach the front end, the side overlap amount also increases as it approaches the front end (approaching the front overlap amount H1).

[0058] Each frame 100-102 constituting the surrounding frame 85 does not cover the lower ends of each wall 96-98 constituting the rising wall 13. In other words, a vertical gap is formed between the lower surface of the surrounding frame 85 of the top plate 2 and the upper wall (inclined wall 10 and flat wall 11) of the case body 9. The vertical width of this gap is uniform around the entire circumference of the surrounding frame 85, and in this embodiment, it is set to approximately 22 mm (when no cooking container P is placed on the top plate 2), that is, a size that allows a cook to insert their fingers. Therefore, if spills from the cooking container P land on the lower end of the rising wall 13, the cook can easily wipe them away with a cloth or the like.

[0059] As described above, the top plate 2 of the cooker according to this embodiment includes a top plate 67 that constitutes the top surface and a reinforcing frame 70 made of a rigid material and positioned on the underside of the top plate 67. Specifically, the top plate 67 is divided into a cooking area 67C supported from below at the upper end surface of the heating unit 3 and a window area 67W that is continuous with the front side of the cooking area 67C, and the window area 67W includes a transparent operation window 74 that faces the operation unit 16 from above. The reinforcing frame 70 integrally comprises a circumferential surrounding frame 85 that surrounds the heating unit 3 in a plan view and follows the periphery of the cooking area 67C, and a pair of reinforcing arms 86 that support both the left and right sides of the operation window 74 in the window area 67W. With the reinforcing frame 70, which integrally comprises these surrounding frame 85 and reinforcing arms 86, each area 67C and 67W of the top plate 67 can be accurately reinforced, and the overall strength of the top plate 67 can be increased without fixing the top plate 2 to the casing 1. In the cooking area 67C, the peripheral area, which tends to lack strength, that is, the area outside the part supported by the heating unit 3, can be reinforced by the surrounding frame 85. In the window area 67W, since the reinforcing frame 70 is not placed at the front end of the operation window 74, the strength of the operation window 74 can be ensured by supporting both the left and right sides of the operation window 74 with reinforcing arms 86 without narrowing the view of the cook looking down at the control unit 16 through the operation window 74.

[0060] More specifically, the top plate 2 includes a magnetic shielding plate 68 positioned between the top plate 67 and the reinforcing frame 70. The magnetic shielding plate 68 integrally comprises a plate body 78 sandwiched between the cooking area 67C and the surrounding frame 85, and a pair of left and right support arms 79 sandwiched between the window area 67W and the reinforcing arms 86. With this configuration, the top plate 2 can be further strengthened by forming a laminated section in which the top plate 67, the magnetic shielding plate 68, and the reinforcing frame 70 overlap in three layers vertically at the periphery of the cooking area 67C of the top plate 67 and on both the left and right sides of the operation window 74 of the window area 67W.

[0061] By installing a bridging section 80 that extends to the left and right between the front ends of a pair of support arms 79 of the magnetic shield plate 68, the strength of the pair of support arms 79 and, consequently, the strength of the front part of the top plate 67 can be further increased.

[0062] Since a reinforcing piece 71 parallel to the bridged section 80 is joined to the lower surface of the bridged section 80, the bridged section 80 is made substantially thicker vertically, and while maintaining strength, the bridged section 80 is made thinner front to back, so as not to narrow the field of view of the cook looking down at the operating section 16 through the operating window 74 as much as possible.

[0063] Since the top plate 67 and the magnetic shield plate 68 are formed in a rectangular plate shape having the same outer shape in a plan view, the periphery of the top plate 67 can be supported from below by the magnetic shield plate 68, thereby increasing the strength of the periphery. Furthermore, by providing a rectangular outer frame 69 along the four peripheries of the top plate 67 and the magnetic shield plate 68, the four peripheries can be protected from impact by cooking containers P that the cook brings onto the top plate 2.

[0064] Casing 1 includes a box-shaped case body 9 with an opening on its top surface, and a rectangular frame-shaped rising wall 13 that rises from the periphery of the opening. This rising wall 13 effectively prevents water (liquid), such as spills from the cooking container P, from entering the casing 1 through the opening on the top surface, even if it splashes onto the top surface of the case body 9. Furthermore, the surrounding frame 85 of the reinforcing frame 70 provided on the top plate 2 surrounds at least the upper end of the rising wall 13 with a gap, so that water can be prevented from directly splashing onto the upper end by the surrounding frame 85. Even if water splashes on the lower part of the rising wall 13, it cannot enter the casing 1 unless it rises along the outer surface of the rising wall 13, making such entry extremely difficult. With these rising wall 13 and surrounding frame 85, a trap-like waterproof structure is formed around the opening on the top surface of the casing 1, effectively preventing water from entering through the opening.

[0065] In addition, in this embodiment, the front overlap amount H1, defined by the vertical distance from the upper end of the front vertical wall 96 of the rising wall 13 to the lower end of the front frame 100 of the surrounding frame 85, is set to be larger than the rear overlap amount H2, defined by the vertical distance from the upper end of the rear vertical wall 97 of the rising wall 13 to the lower end of the rear frame 101 of the surrounding frame 85. Since the front side of the cooking appliance is more likely to get wet than the rear side, setting the front overlap amount H1 to be larger as described above makes it possible to more effectively prevent water from entering the casing 1.

[0066] Since the front part of the upper wall of the case body 9 is made into an inclined wall 10 that slopes downwards toward the front, water that splashes onto the upper wall of the case body 9, which is relatively likely to get wet, can be allowed to flow forward, preventing water from accumulating. Furthermore, since the front vertical wall 96 of the vertical wall 13 is provided in conjunction with the inclined wall 10, while the rear vertical wall 97 of the vertical wall 13 is provided in conjunction with the flat wall 11 on the rear side of the inclined wall 10, the vertical height dimension of the front vertical wall 96 can be set to be greater than the vertical height dimension of the rear vertical wall 97 without unnecessarily increasing the overall vertical height of the casing 1. By making the front vertical wall 96 of the vertical wall 13 higher in this way, water can be more effectively prevented from entering the casing 1, which is relatively likely to get wet toward the front of the cooking appliance. [Explanation of Symbols]

[0067] 1 Casing 2 Top Plate 3 Heating Unit 4 Weighing device 9 Case body 10 Slanted wall 11 flat wall 13. Vertical wall 16 Control section 36 Heating coil 67 Top plate 67C cooking area 67W window area 68 Magnetic shielding plate 69 Outer frame 70 Reinforcement slots 71 Reinforcement piece 74 Operation window 78 main body 79 Support arm 80 Bridge 85 Encirclement Frames 86 Reinforced Arm 96 Forefront wall 97 Rear standing wall 100 front frame 101 Last frame H1 Overlap amount on the front side H2 Overlap amount on the back side

Claims

1. A top plate (2) on which the object to be heated is placed, A heating unit (3) that supports the top plate (2) from below and heats the object to be heated, A weighing device (4) supports the heating unit (3) from below and measures the weight of the object to be heated, A casing (1) that houses the heating unit (3) and the measuring device (4), An operating section (16) is provided at the front of the casing (1), It is equipped with, The top plate (2) includes a top plate (67) that forms the top surface and a reinforcing frame (70) made of a rigid material and positioned on the underside of the top plate (67). The top plate (67) is divided into a cooking area (67C) supported from below by the upper end surface of the heating unit (3), and a window area (67W) that is continuous with the front of the cooking area (67C). The window area (67W) includes a transparent operating window (74) that faces the operating section (16) from above. An electromagnetic induction heating cooker characterized in that the reinforcing frame (70) integrally comprises a circumferential surrounding frame (85) that surrounds the heating unit (3) in a plan view and follows the periphery of the cooking area (67C), and a pair of reinforcing arms (86) that support both the left and right sides of the operation window (74) in the window area (67W).

2. The top plate (2) includes a magnetic shield plate (68) positioned between the top panel (67) and the reinforcing frame (70), The electromagnetic induction heating cooker according to claim 1, wherein the magnetic shield plate (68) integrally comprises a plate body (78) sandwiched between a cooking area (67C) and a surrounding frame (85), and a pair of left and right support arms (79) sandwiched between a window area (67W) and a reinforcing arm (86).

3. The electromagnetic induction heating cooker according to claim 2, wherein a bridging portion (80) extending to the left and right is installed between the front ends of a pair of support arms (79) of the magnetic shield plate (68).

4. The electromagnetic induction heating cooker according to claim 3, wherein a reinforcing piece (71) extending parallel to the bridging portion (80) is joined to the lower surface of the bridging portion (80).

5. The top plate (67) and the magnetic shield plate (68) are formed in the shape of rectangular plates having the same outer frame in a plan view. The electromagnetic induction heating cooker according to claim 3 or 4, wherein a rectangular outer frame (69) is provided along the four periphery edges of the top plate (67) and the magnetic shield plate (68).

6. The casing (1) includes a box-shaped case body (9) having an opening on its top surface, and a rectangular frame-shaped rising wall (13) that rises from the periphery of the opening. An electromagnetic induction heating cooker according to any one of claims 1 to 4, wherein the surrounding frame (85) of the reinforcing frame (70) surrounds at least the upper end of the rising wall (13) with a gap between them.

7. The rising wall (13) is comprised of a front rising wall (96) and a rear rising wall (97) that face each other front and back with the heating unit (3) in between. The encirclement frame (85) comprises a front frame (100) facing the outer surface of the front vertical wall (96) of the vertical wall (13), and a rear frame (101) facing the outer surface of the rear vertical wall (97) of the vertical wall (13). The electromagnetic induction heating cooker according to claim 6, wherein the front overlap amount (H1), defined by the vertical distance from the upper end of the front wall (96) to the lower end of the front frame (100), is set to be greater than the rear overlap amount (H2), defined by the vertical distance from the upper end of the rear wall (97) to the lower end of the rear frame (101).

8. The front part of the upper wall of the case body (9) is an inclined wall (10) that slopes downwards toward the front. The rear of the upper wall of the case body (9) is a horizontal flat wall (11) that is continuous with the rear end of the inclined wall (10). The front vertical wall (96) of the vertical wall (13) is provided in a continuous manner with the inclined wall (10), and the rear vertical wall (97) is provided in a continuous manner with the flat wall (11). The electromagnetic induction heating cooker according to claim 7, wherein the vertical height dimension of the front wall (96) is set to be greater than the vertical height dimension of the rear wall (97).

9. The electromagnetic induction heating cooker according to claim 6, wherein a vertical gap is formed between the lower surface of the surrounding frame (85) and the upper wall of the case body (9) into which a cook can insert their fingers.

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