JP2015017747A - Steam generator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steam generator for a heating cooker in which metal components hardly corrode, which can be combined with an evaporation container with good accuracy and which can be assembled/disassembled conveniently.SOLUTION: At a lower surface of a support base 1 made of an annular heat conductive member, a plurality of pieces of heating rods 2 are mounted vertically downwardly at intervals with each other, and by insert molding including the whole support base and a mounting part of the heating rods, a steam separation container 21 is formed. A temperature detection element 61 is mounted on the support base. At the lower part of the steam separation container, an evaporation container 22 is connected air-tightly by surrounding the heating rods from the outside, an induction heating coil 30 is provided by surrounding the evaporation container from the outside, and a magnetic leakage prevention structure body 40 is arranged by further surrounding the induction heating coil from the outside. In the evaporation container, water for evaporation is supplied from a water supply tank 50. At an upper part of the steam separation container, a steam collection container 23 is connected air-tightly, and heated steam is fed into a cooking chamber from a delivery pipe 24.

Description

  This invention relates to a steam generator for supplying steam into a cooking chamber of a heating cooker such as a steam convection oven, improving the assembly structure of the evaporation container and the heating body, combining both with high accuracy, It is devised so that it can be easily assembled and disassembled, and the temperature detection element for heating control can be easily attached.

  The heating cooker is a device for cooking food, and it is arranged in the housing body by opening the cooking chamber for cooking by heating the cooking ingredients to be cooked in the housing body. It is the structure which opens and closes the opening-and-closing door provided in the front, and puts in and out the cooking food to be heated into and out of the cooking chamber. FIG. 1 is a plan view schematically showing the main internal structure of an example of a steam convection heating cooker. An opening / closing door 11 d is provided on the front surface of the housing body 11 of the steam convection heating cooker 10. When the handle 11h is operated to open the open / close door 11d, the cooking chamber 12 opens toward the front. In the cooking chamber 12, the portion on the right side of the broken line 12s in the drawing forms a space for storing the cooked food, and the portion on the left side of the broken line 12s has a heater 13 and a heating chamber. A centrifugal fan 14 for circulating internal air is provided. The centrifugal fan 14 is driven by a motor 14m, and circulates the air in the cooking chamber 12 as indicated by a white arrow. A steam generator 20 is provided in a space adjacent to the left outer side of the cooking chamber 12 in the housing body 11, and steam for cooking is supplied into the cooking chamber 12. The temperature sensor 15 detects the internal temperature of the cooking chamber 12. The control circuit 16 controls the operation of the heating cooker 10 in accordance with an operation instruction input from the operation panel 17 by the user and in accordance with the detected temperatures of necessary portions of the heating cooker 10.

  The steam generator 20 inserts a heating element into the water stored in the evaporation container, inductively heats the heating element from the outside of the evaporation container to boil the water stored therein, and collects the generated steam in the upper steam collection. It is structured so that it is collected in a container and supplied from there to a cooking chamber via a steam delivery pipe. Examples of the steam generator are disclosed in Patent Documents 1 and 2. In this type of steam generator with a conventional structure, a heating element in which a plurality of heating rods are suspended by a support frame at the top is inserted into a vertically long and deep evaporation container from the top and supported at the upper edge of the evaporation container. The frame is suspended, the heating body is heated by an induction heating coil from the outside of the evaporation container, the water inside is boiled, and the boiled water vapor is collected in the upper vapor collection container and taken out by the delivery pipe.

  In this case, the heating body is vertically elongated and has a shape in which a support frame is hung on the upper edge of the deep evaporating vessel, so that the heating rod does not tilt or come too close to the wall surface of the evaporating vessel, and It was difficult to assemble with high precision so as to be arranged in an equal positional relationship with the outer heating coil. If it is not arranged uniformly with high accuracy, it will lead to uneven heating. Also, the temperature of the heating rod is detected by inserting a temperature detection thermistor into the hole opened in the heating rod, and since the heating rod with the hole is inserted from the outside of the evaporation container, it is attached. Therefore, it takes time for positioning work and attention must be paid to the seal structure. In addition, if a thermistor is attached to a heating rod located in the water to be heated, water impurities such as calcium are likely to adhere to the thermistor itself, and the temperature detection sensitivity may be lowered or unstable, resulting in reliability. There is also a worry in terms of

JP 2010-249410 A JP 2010-255871 A

  According to the present invention, in the steam generator of the heating cooker, by improving the assembly structure of the evaporation container and the heating body, both can be combined with high accuracy and can be easily assembled and disassembled. It is an object of the present invention to provide a steam generator that can be easily mounted with a temperature detecting element and has a high detection temperature reliability.

  In order to solve the above-described problems, a steam generator according to the present invention includes a support base made of a heat conductive member having an annular shape having an opening in the center in a horizontal plane and a predetermined thickness, and each upper end is A plurality of induction heating heating rods attached to the support base with a predetermined interval and standing vertically downward with respect to the annular surface of the support base, and the entire support base and the heating rod A steam separation container that is insert-molded with a synthetic resin material including an attachment portion and that is formed integrally with a cylindrical portion that extends upward from the support base, and a plurality of heating rods are surrounded by a lower portion of the steam separation container. A bottomed cylindrical evaporation container that is airtightly connected, a steam collection container that is airtightly connected to the top of the steam separation container and collects the vapor from the vapor separation container and sends it out from the delivery pipe, and a cylinder that surrounds the evaporation container from the outside Heating provided An induction heating coil for induction heating, a magnetic leakage prevention structure including a magnetic material arranged around the induction heating coil from the outside, a water supply tank that communicates with the evaporation container and supplies water to the evaporation container, It is characterized by comprising.

  In the steam generator according to the present invention, a temperature detection hole is formed in the outer peripheral side surface of the support base, and a temperature is detected from the outside through a portion adjacent to the support base of the steam separation container formed integrally with the support base. It can be set as the structure which attaches a temperature detection element to a detection hole. Furthermore, in the steam generator according to the present invention, a convex piece-shaped temperature detection piece portion is formed upright in an L shape integrally with the support base from a part of the outer periphery of the support base, and is integrated with the support base. A structure may be adopted in which a temperature-sensitive switch is attached to the temperature detection piece from the outside through a portion adjacent to the support base of the molded vapor separation container.

  In the steam generator according to the present invention, the magnetic leakage prevention structure includes a plurality of ferrite rod-shaped bodies arranged with the longitudinal direction oriented in the vertical direction, a reinforcing bar adjacent to each ferrite rod-shaped body along the longitudinal direction, It comprises an upper support frame and a lower support frame that have an arc shape in a plane perpendicular to the longitudinal direction of the ferrite rod-shaped body, and each upper end and each lower end of the ferrite rod-shaped body and the reinforcing bar are respectively The upper support frame and the lower support frame are joined to each other at a predetermined interval in the arc direction, and a ferrite rod-like body is insert-molded integrally with the reinforcing bar, the upper support frame, and the lower support frame. The ferrite rod-shaped body may be structured so as to surround the induction heating coil from the outside.

  In the steam generator according to the present invention, the water supply tank is a bottomed container that supplies water by dropping water from the top, and can have a structure in which an inclined wall surface is formed on the bottom surface corresponding to the location where the water falls. .

  According to this invention, in the steam generator, a plurality of heating rods capable of induction heating are provided on a support base made of a heat conducting member having an annular shape having an opening in the center in a horizontal plane and having a predetermined thickness. Attach the upper end of each support to the support base at a predetermined interval, stand vertically downward with respect to the annular surface of the support base, and include the entire support base and the mounting part of the heating rod Since the support base is made of metal with good thermal conductivity, it is not corroded by moisture, and when the support base and the heating rod are dissimilar metals, Can also be prevented. In addition, since the vapor separation container is formed by integrally forming a cylindrical part extending upward from the support base, a plurality of heating rods are enclosed in the part below the support base to connect the evaporation container accurately and airtightly. In addition, a vapor separation container is formed in a portion above the support base, and water droplets that have jumped from the bottom with boiling can be settled and dropped. Further, in the support base portion, the steam passage is narrowed at the opening of the central portion, so that the water droplets that boil and bounce below are blocked there, and the amount of the water splashing up is reduced. Furthermore, a steam collecting container can be connected to the upper part of the steam separating container in an airtight manner. Also, a temperature detection hole is formed in the outer peripheral side surface of the support base made of a heat conducting member, and a temperature detection element is attached to the temperature detection hole from the outside through a portion of the synthetic resin molded integrally with the support base. By adopting the structure, it is easy to attach the temperature detection element for heating control. In addition, since the temperature detection element is attached to the support base that does not splash water on the heating rod, it does not adhere to impurities such as calcium contained in the water, resulting in a decrease in detection sensitivity. And the possibility of malfunctions such as difficulty in removal.

It is a top view which shows diagrammatically the main internal structure about an example of a steam convection type heating cooker. It is a perspective view which shows the external appearance of the steam generator by this invention with the peripheral apparatus. It is the cross-sectional elevation view which looked at the steam generator by this invention from the direction of arrow A of FIG. It is a perspective view which shows the state in which the heating rod in the steam generator by this invention was attached to the support base. It is a section elevation view of a steam storage cylinder formed by insert-molding a heating rod in the steam generator according to the present invention. It is a perspective view of the steam | steam storage cylinder formed by insert-molding the heating rod in the steam generator by this invention. It is a top view of the bumping shielding board in the steam generator by this invention. It is a perspective view which shows the external appearance which decomposed | disassembled some steam generators by this invention. It is a horizontal sectional view of the magnetic leakage prevention structure in the steam generator according to the present invention. FIG. 3 is a sectional elevational view of the steam generator according to the present invention as viewed from the direction of arrow B in FIG. 2.

  Below, the steam generator by this invention is demonstrated, referring drawings. FIG. 2 is a perspective view showing the appearance of the steam generator according to the present invention together with the peripheral devices, and FIG. 3 is a sectional elevation view of the steam generator according to the present invention as viewed from the direction of arrow A in FIG. is there. The steam generator according to the present invention has the appearance shown in the perspective view of FIG. 2 as a whole, and has the internal structure shown in the sectional elevation view of FIG. 3, and evaporates by boiling the water stored in the interior. A vapor separation vessel 21 for calming and dropping water droplets boiled and bounced from below and leading the vapor upward is hermetically connected to the upper portion of the bottomed cylindrical evaporation vessel 22 to be discharged, and further to the upper portion of the vapor separation vessel 21 Is connected to the steam collecting container 23 having a closed ceiling wall in an airtight manner to form a vertically long cylindrical container for generating steam. Steam is ejected from the delivery pipe 24 provided on the side wall near the ceiling wall of the steam collecting container 23 at the uppermost part and fed into the cooking chamber 12 (FIG. 1). The evaporation container 22 communicates with a water supply tank 50 at a lower portion thereof, and water is constantly supplied from the water supply tank 50. Reference numeral 51 denotes a water supply communication pipe that forms a water supply path from the water supply tank 50 to the evaporation container 22. In addition, a plurality of heating rods 2 are arranged in the evaporation container 22, and an induction heating coil 30 wound around the evaporation container 22 from the outside and wound in a cylindrical shape is provided outside the evaporation container 22. It has been. Further, the magnetic leakage prevention structure 40 is arranged so as to surround the induction heating coil 30 from the outside.

  Next, the arrangement structure of the heating rod 2 which is a feature of the present invention will be described with reference to FIGS. As shown in FIG. 4, the bottom surface of the support base 1 made of a material having a good thermal conductivity such as copper, which has a circular shape with a flat opening in the horizontal direction and a circular opening in the center, and has a predetermined thickness, A plurality of heating rods 2 made of a material such as stainless steel capable of electromagnetic induction heating are attached with screws 3 at their upper ends spaced apart from each other, and vertically downward with respect to the annular surface of the support base 1 A forest is established. The support base 1 is provided with a temperature detection hole 1a on the outer peripheral side surface thereof, and a temperature detection piece 1b is integrally formed from a part of the outer periphery and is erected upward in an L shape. As shown in FIG. 5, the entire support base 1 configured as described above and the mounting portion of the heating rod are inserted inside with a synthetic resin material and extend upward from the support base 1. The vapor separation container 21 is formed integrally with the shape portion. The vapor separation container 21 is a space that serves to settle and drop water droplets that boil and jump in an evaporation container 22 described below.

  FIG. 6 is a perspective view of a vapor separation vessel 21 in which a support base 1 (not shown in the figure) to which a heating rod 2 is attached is insert-molded at the lower portion. 1 is provided with a through hole that reaches the temperature detection hole 1a, and a through hole that reaches the flat surface of the protruding temperature detection piece 1b of the support base 1 is provided at a position 21b in the figure. It has been. The heating temperature is detected by a temperature detection element 61 (see FIGS. 2 and 3) such as a thermistor attached to the temperature detection hole 1a, and heating control for generating steam is performed. A surface contact type temperature sensitive switch 62 (see FIG. 5) such as a bimetal thermostat is attached to the rising surface of the temperature detecting piece 1b and used to shut off the heating circuit when abnormal heating or the like is detected. . Since the support base 1 is made of a thick member made of a material having good heat conduction, it sufficiently conducts the temperature of the plurality of heating rods and serves to detect the average temperature of the plurality of heating rods. On the other hand, materials with good thermal conductivity, such as copper and brass, are susceptible to corrosion due to the action of moisture, and electrolytic corrosion is likely to occur at the joint between copper and stainless steel. Because it is wrapped in and isolated from moisture, such a problem does not occur. Furthermore, since temperature detection for temperature control and temperature detection for operation stop control at the time of abnormality are performed at two locations on the same support base 1 having good heat conduction, the safety of the heating cooker 10 is greatly improved.

  Convex ridges 21c and 21d that are continuous in the circumferential direction are integrally formed on the outer peripheral surface of the cylinder of the vapor separation vessel 21, and serve as reinforcing ribs for the cylindrical portion. When the steam collecting container 23 is connected from above, it serves as a positioning stopper for the lower end edge of the steam collecting container 23. Further, as described above with reference to FIG. 3, the bottomed evaporation container 22 is hermetically connected to the bottom of the vapor separation container 21 and is heated by the induction heating coil 30. The water in the evaporation container 22 is boiled and evaporated by the heat generated in 2 to generate steam. The generated steam rises to the vapor separation container 21, further rises to the steam collection container 23, and is sent from the delivery pipe 24 into the cooking chamber. As shown in FIGS. 3 and 5, O-rings 21 e and 21 f are fitted at locations where the evaporation container 22 is connected to the lower side of the vapor separation container 21, as shown in FIGS. 3 and 5. Further, at the connection portion with the steam collecting container 23 at the upper end of the steam separation container 21, a flat, disc-shaped water droplet blocking part 25a as shown in FIG. 7 is connected to the outer ring part 25c by the connecting plate part 25b. On the other hand, a bumping shielding plate 25 supported by the central portion of the circle and having a steam passage opening 25d around the water droplet blocking portion 25a is interposed as shown in FIG. In addition, it serves to block water droplets that are not allowed to fall down and that try to jump up toward the steam collecting container 23.

  Next, the magnetic leakage prevention structure will be described with reference to FIGS. FIG. 8 is a perspective view showing an external appearance of a part of the steam generator according to the present invention, and FIG. 9 is a horizontal sectional view of the magnetic leakage prevention structure. The magnetic leakage prevention structure 40 includes a plurality of ferrite rod-like bodies 41 arranged with the longitudinal direction oriented in the vertical direction, a reinforcing bar 42 adjacent to each ferrite rod-like body 41 in the longitudinal direction, and a ferrite rod-like body. 41 includes an upper support frame body 43 and a lower support frame body 44 that have an arc shape in a plane perpendicular to the longitudinal direction of 41, and each upper end portion and each lower end portion of the ferrite rod-shaped body 41 and the reinforcing bar 42 are The upper and lower support frames 43 and 44 are respectively coupled to the upper support frame 43 and the lower support frame 44 at predetermined intervals in the arc direction, and the ferrite rod-like body 41 is integrally formed with the reinforcing bar 42, the upper support frame 43 and the lower support frame 44. A plurality of ferrite rod-like bodies 41 are disposed so as to surround the induction heating coil 30 from the outside by integrally molding with heat-resistant engineering plastic resin. In this embodiment, the magnetic leakage prevention structure 40 is formed in a half-divided structure of semi-cylindrical surfaces, and can be combined as it is by combining two of the same shape upside down. Molded. Each one is designed in a sandwich shape so that the mold can be removed, as can be seen from the cross-sectional view of FIG. Since ferrite itself is a brittle material and is a sintered product, its external dimensions are likely to vary, and it is not suitable for insert molding and is easily broken. Therefore, by making the adjacent auxiliary bars 42 contact with the ferrite rod-shaped body 41 partially and uniformly in a small area, destruction can be prevented even at a high pressure of 40 MPa of injection molding. The magnetic flux leaking from the induction heating coil 30 is short-circuited in such a manner as to be attracted to the ferrite rod-shaped body 41 which is a good magnetic conductor, so that the magnetic leakage prevention structure 40 is a lattice-like structure with a space between them. The leakage flux is sufficiently attenuated.

  Next, the water supply tank will be described with reference to FIG. The water supply tank 50 is for supplying the water stored therein to the evaporating vessel 22 communicating with the lower part. Generally, the amount of water stored in the water supply tank 50 is detected by a float switch, The tap water is dropped into the water supply tank 50 from above while being controlled so as to have a constant water level. As a feature, the water supply port and the float switch are adjacent to each other. This is because the cross-sectional area of the water supply tank 50 itself is not large, but the function of the water supply tank 50 is to supply water through the steam generator 20 and the water supply communication pipe 51, and the cross-sectional area of the steam generator 20 This is because it is convenient in design if they are made equal. If the water supply tank 50 is designed to be large, the initial water supply takes time. If the water supply tank 50 is designed to be small, the water supply operation becomes frequent and affects the reliability of the float switch and the water valve for water supply (not shown). Come. However, if the float switch is adjacent to the water inlet, malfunction of the float switch is likely to occur. The shape of the container of the water supply tank 50 is often a simple rectangular parallelepiped, and the bottom surface is generally a horizontal plane except for the portion of the water supply communication pipe 51, but the tap water discharged during water supply is from above. If it is struck against a flat bottom surface, the water surface will not be stable, for example, the water will bounce and air will be trapped, and the float 52 of the float switch will hit the float 52 and the float 52 will be caught on the shaft. There is a possibility that the float 52 of the float switch cannot accurately indicate the water level. In the embodiment of the present invention shown in FIG. 9, the inclined wall surface 50a is formed on the bottom surface corresponding to the location where the water from the water supply pipe 59 falls, and 50b is formed on the opposite side. As a result, the flow of water supplied from the water supply pipe 59 is guided by the inclined surface 50a and flows horizontally along the bottom surface toward the inclined surface 50b, where the water flows upward, and the water flow is generally gentle. The water level rises across the street. The phenomenon that the float 52 is inclined and caught is less likely to occur.

  Furthermore, in the embodiment of FIG. 10, a cylindrical wave preventing wall 53 is provided so as to surround the float 52 of the float switch. Even if the wave preventing wall 53 is not cylindrical, it is also effective to provide a wall plate only on the side where the water supply pipe 59 is provided. Thereby, the wave surface of the water surface where the float 52 exists is eliminated, and the water level is detected more accurately by the float 52. In addition, as shown in FIG. 10, by implementing in combination with both the inclined wall surface 50a and the anti-ripple wall 53, a stable water supply function can be provided even with a strong water pressure.

  As described above, in the embodiment of the steam generator for a heating cooker according to the present invention, the upper ends of a plurality of heating rods are attached to a support base made of a circular heat transfer member, and the entire support base Since the steam storage cylinder is constructed by integrally forming a cylindrical part that extends upward from the support base by insert molding with a synthetic resin material including the mounting part of the heating rod, it is accurate with respect to the evaporation container Can be connected in combination. In addition, since the temperature of the support base made of the heat conducting member is detected and the heating control is performed, the temperature corresponding to the temperature of the plurality of heating rods itself is detected, and the temperature detection element is detected from the outer surface of the vapor separation container. Can be easily installed. Moreover, since the ferrite rod-shaped body for preventing leakage magnetic flux is insert-molded together with the reinforcing bars and the upper and lower support frame bodies, the risk of damage to the ferrite rod-shaped body is reduced. Further, since the water surface of the supplied water is stabilized by inclining the shape of the bottom wall of the water supply tank, the possibility of malfunction of the float of the float switch is reduced.

  DESCRIPTION OF SYMBOLS 1 ... Support base, 1a ... Temperature detection hole, 1b ... Temperature detection piece part, 2 ... Heating rod, 3 ... Screw, 10 ... Heating cooker, 11 ... Housing main body, 11d ... Opening / closing door, 11h ... Handle, 12 ... Cooker, 13 ... heater, 14 ... centrifugal fan, 15 ... temperature sensor, 16 ... control circuit, 17 ... operation panel, 20 steam generator, 21 ... steam separation container, 21a ... through hole, 21b ... through hole, 21c ... Projections, 21d ... Projections, 22 ... Evaporation vessel, 23 ... Vapor collection vessel, 24 ... Sending tube, 25 ... Bumping shield, 30 ... Induction heating coil, 40 ... Magnetic leakage prevention structure, 41 ... Ferrite rod Body: 42 ... Reinforcing bar, 43 ... Upper support frame, 44 ... Lower support frame, 50 ... Water supply tank, 51 ... Water supply communication pipe, 52 ... Floating element, 53 ... Ripple prevention wall, 59 ... Water supply pipe, 61 ... Temperature detecting element, 62 ... temperature sensitive switch.

Claims (5)

A support base made of a heat conductive member having an annular shape having an opening in the center in a horizontal plane and having a predetermined thickness;
A plurality of heating rods capable of induction heating, each upper end being attached to the support base at a predetermined interval, and standing vertically downward with respect to the annular surface of the support base;
A vapor separation container integrally formed with a cylindrical portion that is insert-molded with a synthetic resin material including the entire support base and the mounting portion of the heating rod, and extends upward from the support base;
A bottomed cylindrical evaporation vessel surrounding the plurality of heating rods and hermetically connected below the vapor separation vessel;
A vapor collection container that is airtightly connected to an upper portion of the vapor separation container and collects the vapor from the vapor separation container and sends it out from a delivery pipe;
An induction heating coil that surrounds the evaporation vessel from the outside and is provided in a cylindrical shape and induction-heats the heating rod;
A magnetic leakage prevention structure comprising a magnetic material disposed around the induction heating coil from the outside;
A water supply tank that communicates with the evaporation container and supplies water to the evaporation container;
A steam generator comprising: The steam generator according to claim 1,
A temperature detection hole is formed in an outer peripheral side surface of the support base, and a portion adjacent to the support base of the vapor separation container formed integrally with the support base passes through the temperature detection hole from the outside. A steam generating device comprising a temperature detecting element. The steam generator according to claim 2,
The steam separation container formed integrally with the support base and formed in a L-shape with a convex piece-shaped temperature detection piece from a part of the outer periphery of the support base. A steam generating device characterized in that a temperature sensitive switch is attached to the temperature detecting piece from outside through a portion adjacent to the support base. The steam generator according to claim 1,
The magnetic leakage prevention structure includes a plurality of ferrite rod-shaped bodies arranged with their longitudinal directions oriented vertically, reinforcing bars adjacent to the ferrite rod-shaped bodies along the longitudinal direction, and the ferrite rod-shaped bodies. An upper support frame and a lower support frame each having an arc shape in a plane perpendicular to the longitudinal direction, and each upper end and each lower end of each of the ferrite rod-shaped body and the reinforcing bar are respectively supported by the upper support. The upper support frame body is coupled to the frame body and the lower support frame body at a predetermined interval in the arc direction, and the ferrite rod-shaped body is adjacent to the reinforcing bar in a partial area and uniformly. The steam is formed by insert molding integrally with the lower support frame, and the plurality of ferrite rod-shaped bodies are disposed so as to surround the induction heating coil from the outside. Raw devices. The steam generator according to claim 1,
The water supply tank is a bottomed container of a type that supplies water by dropping water from an upper part, and an inclined wall surface is formed on a bottom surface corresponding to a location where the water falls.

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