JP4229860B2 - Steam cooker - Google Patents

Description

    The present invention relates to a steam cooker.

Many proposals have been made so far regarding steam cookers that perform cooking using steam. Examples thereof can be seen in Patent Documents 1 to 3. Patent Document 1 describes a steam cooking apparatus that injects steam into a food tray. Patent Document 2 describes a cooking device that sends superheated steam to an oven cabinet, or converts the steam in the oven cabinet to superheated steam by radiation heating. Patent Document 3 describes a cooking device that supplies superheated steam to one or both of the entire heating chamber and the vicinity of the food.
Japanese Utility Model Publication No. 3-67902 (full text description, page 4-6, FIG. 1-3) JP-A-8-49854 (page 2-3, FIGS. 1, 2-8) Japanese Patent Laid-Open No. 11-141881 (page 3-5, FIG. 1-3)

    If the steam cooker is classified in terms of where to place the steam generator, it can be divided into two types: an external arrangement method and an internal arrangement method. The device described in Patent Document 1 employs an external arrangement method, and the devices described in Patent Documents 2 and 3 employ an internal arrangement method. In the case of the external arrangement method, a steam generator having a large size and high steam generation capability can be used, but the configuration becomes large and it is difficult to say that it is suitable for home use.

    The present invention provides a steam cooker of a type in which a steam generator is arranged in a machine, and a circulation system for supplying steam to a heating chamber is configured to have a short path distance and low pressure loss and heat loss. The objective is to improve efficiency.

(1) A steam cooker according to the present invention is a steam cooker provided with a heating chamber in which an object to be heated is placed, and an external circulation path that sucks the gas in the heating chamber and recirculates the sucked gas back to the heating chamber. The external circulation path is disposed at a position close to the outer surface of the one side wall, which is formed on one side wall of the heating chamber, and is communicated with the suction port. And a blower that forms an airflow that flows through the external circulation path, and is disposed at a position that is close to the outer surface of the one side wall and that can supply steam to the airflow that flows through the external circulation path. is, in the steam cooker and a steam generator supplying steam to the airflow flowing through the outer circulation passage, the outer circulation passage after having passed the steam generator is provided adjacent to the heating chamber Sabukyabite The subcavity has a built-in gas heating heater that heats the steam flowing through the external circulation path, and a hole is formed in a bottom panel of the subcavity, and the heating chamber is formed through the hole. It is characterized by being supplied with steam.

(2) In the steam cooker having the above-described configuration, one or both of the upper surface and the lower surface of the bottom panel is dark.

    (3) In the steam cooker having the above-described configuration, the steam generation device includes a steam suction portion at an upper portion, and the external circulation path forms an airflow passing through the steam suction portion.

    (4) In the steam cooker having the above-described configuration, the steam generator includes a steam suction portion at an upper portion, and the external circulation path forms an air flow passing through the steam suction portion, and the steam suction portion is configured to be the subcavity. Are provided at approximately the same height.

    (5) In the steam cooker having the above-described configuration, the suction port is disposed at an upper corner of the one side wall, and the blower device includes a centrifugal fan. It arrange | positions so that it may face the direction of a vapor | steam suction part.

    With the above configuration, the following effects are achieved.

(1) The external circulation path for sucking the gas in the heating chamber and returning the sucked gas to the heating chamber again is a position close to the suction port formed on one side wall of the heating chamber and the outer surface of the one side wall. An air blower that is disposed at a position communicating with the suction port and forms an airflow that sucks gas from the suction port and flows in the external circulation path, and is also in the vicinity of the outer surface of the one side wall, An external circulation after passing through the steam generator in a steam cooker, which is disposed at a position where steam can be supplied to the airflow flowing through the circulation path and which supplies steam to the airflow flowing through the external circulation path The passage is connected to a sub-cavity provided adjacent to the heating chamber, and the sub-cavity incorporates a gas heating heater for heating the steam flowing through the external circulation passage, and has a bottom of the sub-cavity. The panel has holes drilled steam into the heating chamber through the holes is characterized in that it is supplied. For this reason, the length of the external circulation path is short, the pressure loss is reduced, and the blowing efficiency of the blower is improved. Further, since the length of the external circulation path is short, heat loss due to heat dissipated therefrom is low, and thermal efficiency is also high. Moreover , since a large space is not required for arranging the external circulation path, the entire steam cooker can be reduced in size. Further, by providing the gas temperature raising heater inside the subcavity, the steam flowing in the subcavity is heated, and the subcavity itself is also radiantly heated. Moreover, the to-be-heated material can be cooked more efficiently by making a hole in the bottom panel of the subcavity.

(2) In the bottom panel, either one or both of the top and bottom surfaces are dark. As a result, the bottom panel absorbs the radiant heat emitted from the temperature raising heater well, the temperature rise of the subcavity and its outer surface is suppressed, safety is improved, and the radiant heat of the temperature raising heater is transferred to the heating chamber through the bottom panel. Informed, the heating chamber is heated more efficiently.

    (3) Since the steam generator is provided with a steam suction part in the upper part and the external circulation path forms an air flow passing through the steam suction part, a new steam is contained in the circulation air flow while maintaining the circulation air flow. Can be imported.

    (4) The steam generator has a steam suction part at the top, and the external circulation path forms an air flow passing through the steam suction part, and the steam suction part and the subcavity are provided at substantially the same height. The vapor suction part and the subcavity can be linearly connected by a horizontal duct. Thereby, the external circulation path after passing the steam suction part can be made the shortest path.

    (5) The suction port of the external circulation path is arranged at the upper corner of one side wall of the heating chamber, and the fan casing of the centrifugal fan of the blower is directed toward the steam suction unit of the steam generator. To be arranged. As a result, the gas flowing in from the suction port reaches the steam suction part through the shortest route as the blowing route by the centrifugal fan, so the length of the external circulation path is shortened and the pressure loss during blowing is reduced, The ventilation efficiency of the external circulation path is improved.

    Hereinafter, an embodiment of a steam cooker according to the present invention will be described with reference to FIGS. 1 is an external perspective view, FIG. 2 is an external perspective view with the heating chamber door open, FIG. 3 is a front view with the heating chamber door removed, FIG. 4 is a basic structural diagram of the internal mechanism, and FIG. Is a basic structural view of the internal mechanism viewed from a direction perpendicular to FIG. 4, FIG. 6 is a top view of the heating chamber, FIG. 7 is a vertical sectional view of the steam generator, and FIG. 8 is taken along the line AA in FIG. 9 is a horizontal sectional view taken along line BB in FIG. 7, FIG. 10 is a front view of the steam generator, FIG. 11 is a vertical sectional view of the blower, and FIG. 12 is a bottom panel of the subcavity. 13 is a control block diagram, FIG. 14 is a basic structural view similar to FIG. 4 and shows a different state from FIG. 4, and FIG. 15 is a basic structural view similar to FIG. 5 and a different state from FIG. Is shown.

    The steam cooker 1 includes a rectangular parallelepiped cabinet 10. A door 11 is provided in front of the cabinet 10. The door 11 rotates in a vertical plane centering on the lower end. By grasping the upper handle 12 and pulling it forward, the door 11 is changed from the vertical closed state shown in FIG. 1 to the horizontal open state shown in FIG. 90 ° attitude change is possible. The door 11 has a configuration in which a left portion 11L and a right portion 11R, which are finished with a metal decorative plate, are symmetrically arranged on the left and right sides of a central portion 11C having a see-through portion fitted with heat-resistant glass. An operation panel 13 is provided on the right portion 11R.

    When the door 11 is opened, the front of the cabinet 10 is exposed. A heating chamber 20 is provided at a location corresponding to the central portion 11 </ b> C of the door 11. A water tank chamber 70 is provided at a location corresponding to the left side portion 11L of the door 11. No opening is provided at a location corresponding to the right portion 11R of the door 11, but a control board is disposed inside the location.

    The heating chamber 20 has a rectangular parallelepiped shape, and the front side facing the door 11 is entirely open. The remaining surface of the heating chamber 20 is formed of a stainless steel plate. Heat insulation measures are taken around the heating chamber 20. A stainless steel plate receiving tray 21 is placed on the floor of the heating chamber 20, and a stainless steel wire rack 22 on which the object to be heated F is placed is placed on the receiving tray 21.

    Steam in heating chamber 20 (normally, the gas in heating chamber 20 is air, but when steam cooking is started, air is replaced by steam. In this specification, the gas in heating chamber 20 is steam. The explanation will be made assuming that it has been replaced with (3)), and circulates through the external circulation path 30 shown in FIG.

    The starting end of the external circulation path 30 is a suction port 28 formed at one corner of the upper side wall of the heating chamber 20. In this embodiment, as can be seen in FIG. 3, the suction port 28 is arranged in the upper left corner of the side wall. The suction port 28 is formed by arranging a plurality of horizontal slits in the vertical direction, and the upper slit is longer and shorter as it goes downward to form a right triangle opening as a whole (see FIG. 11). The right angle of the right triangle is adjusted to the angle of the side wall at the back of the heating chamber 20. That is, the opening degree of the suction port 28 is larger as it is closer to the upper side of the side wall at the back of the heating chamber 20. The closer to the left side, the larger.

    Following the suction port 28 is a blower 25 that forms an airflow flowing in the external circulation path 30. The blower device 25 is disposed close to the outer surface of one side wall of the heating chamber 20. A side wall at the back of the heating chamber 20 is selected as one side wall. As shown in FIG. 11, the blower 25 includes a centrifugal fan 26, a fan casing 27 that accommodates the centrifugal fan 26, and a motor 29 that rotates the centrifugal fan 26. A sirocco fan is used as the centrifugal fan 26. As the motor 29, a DC motor capable of high speed rotation is used. The fan casing 27 is fixed to the lower right position of the suction port 28 on the outer surface of the rear side wall of the heating chamber 20.

    The fan casing 27 has a suction port 27a and a discharge port 27b. The discharge port 27b is oriented in a specific direction, and the meaning of the direction will be described later.

    A steam generator 50 follows the blower 25 in the external circulation path 30. Details of the steam generator 50 will be described later. Similarly to the blower device 25, the steam derivation device 50 is disposed close to the outer surface of the rear side wall of the heating chamber 20. However, while the blower 25 is disposed at a position on the left side of the heating chamber 20, the steam generator 50 is on the center line of the heating chamber 20.

    In the external circulation path 30, a section from the discharge port 27 b of the fan casing 27 to the steam generator 50 is constituted by a duct 31. The section after exiting the steam generator 50 is constituted by a duct 35. The duct 35 is connected to a subcavity 40 provided adjacent to the heating chamber 20.

    The subcavity 40 is provided on the ceiling portion of the heating chamber 20 at a location corresponding to the center portion of the ceiling portion in plan view. The subcavity 40 has a planar circular shape, and a gas temperature raising heater 41 serving as a steam heating means is disposed inside the subcavity 40. The gas temperature raising heater 41 includes a main heater 41a and a sub heater 41b, both of which are constituted by sheathed heaters. An opening having the same size as the subcavity 40 is formed in the ceiling portion of the heating chamber 20, and a bottom panel 42 constituting the bottom surface of the subcavity 40 is fitted therein.

    A plurality of upper blow holes 43 are formed in the bottom panel 42. Each of the upper blow holes 43 is a small hole directed directly below, and is distributed over the entire panel. The upper blow holes 43 are two-dimensionally distributed in a plane, that is, two-dimensionally distributed. However, the bottom panel 42 may be provided with projections and depressions to take into account three-dimensional elements.

    The bottom panel 42 is finished in a dark color on both the upper and lower surfaces by a surface treatment such as painting. The bottom panel 42 may be formed of a metal material that changes color to dark when used repeatedly. Alternatively, the bottom panel 42 may be formed of a dark-colored ceramic molded product.

    Instead of forming the bottom surface of the subcavity 40 with the separate bottom panel 42, the top plate of the heating chamber 20 can also be used as the bottom surface of the subcavity 40 as it is. In this case, the upper blow hole 43 is provided at a position corresponding to the subcavity 40 in the top plate, and both the upper and lower surfaces thereof are finished in a dark color.

    Small sub-cavities 44 are provided outside the left and right side walls of the heating chamber 20 as shown in FIG. The subcavity 44 is connected to the subcavity 40 by a duct 45 and receives supply of steam from the subcavity 40 (see FIGS. 5 and 6). The duct 45 is constituted by a pipe having a circular cross section. It is desirable to use a stainless steel pipe.

    In the lower portion of the side wall of the heating chamber 20, a plurality of side air holes 46 are provided at locations corresponding to the subcavities 44. Each side blow hole 46 is a small hole directed in the direction of the object to be heated F placed in the heating chamber 20, more precisely, below the object to be heated F, and the object to be heated F placed on the rack 22. Steam is ejected in the direction of. The height and direction of the side blow holes 46 are set so that the jetted steam enters under the object to be heated F. Further, the position and / or direction of the side air holes 46 are set so that the vapors ejected from the left and right meet under the article to be heated F.

    The side blow holes 46 may be formed in a separate panel, or may be formed by directly punching small holes in the side wall of the heating chamber 20. This is the same as the case of the upper fumarole 43. However, unlike the case of the subcavity 40, it is not necessary to finish the portion corresponding to the subcavity 44 in a dark color.

    Note that the sum of the area of the left and right side air holes 46 is larger than the area of the upper air holes 43. In order to supply a large amount of steam to the side blow holes 46 having such a large area, a plurality of (four in the figure) ducts 45 are provided for each subcavity 44.

    Next, the structure of the steam generator 50 will be described. The steam generator 50 includes a cylindrical pot 51 arranged with a center line vertical. The pot 51 has a flat planar profile on the side wall constituting the vertical surface, and has an elongated horizontal cross-sectional shape, that is, a rectangular shape, an oval shape, or a similar horizontal cross-sectional shape. The pot 51 is required to have heat resistance, but may be formed of any material as long as the condition is satisfied. It may be a metal or a synthetic resin. Ceramics can also be used. Different materials may be combined.

    As shown in FIG. 6, the steam generator 50 is attached such that one flat side surface of the pot 51 is parallel to the inner side wall of the heating chamber 20. If it is this form, even if the width | variety of the space of the outer surface of the heating chamber 20 and the inner surface of the cabinet 10 is narrow, the steam generator 50 can be arrange | positioned. Therefore, the width of the space can be reduced to make the cabinet 10 compact, and the space utilization efficiency in the cabinet 10 can be improved.

    It is a steam generating heater 52 arranged at the bottom of the pot 51 that heats the water in the pot 51. The steam generating heater 52 is a sheathed heater, which is immersed in water in the pot 51 to directly heat the water. As seen in FIG. 9, the steam generating heater 52 is bent into a flat horseshoe shape along the inner surface of the pot 51 in accordance with the flat shape of the pot 51. Similar to the gas temperature raising heater 41 in the subcavity 40, the steam generating heater 52 is also composed of a main heater 52a and a subheater 52b, with the former arranged outside and the latter arranged inside. The diameter of the cross section is also different, the main heater 52a is thick, and the sub heater 52b is thin.

    When placing a sheathed heater in a surface with the same area, it is more flat like a horseshoe shape in a rectangular or oval surface than in a case in which a sheathed heater bent into a circle is placed in a circular surface. The length of the sheathed heater is longer in the case where the sheathed heater bent into a proper shape is placed. That is, the ratio of the length of the sheathed heater to the same amount of water is greater when a sheathed heater bent like a horseshoe is placed in a pot with an elongated horizontal sectional shape than in a pot with a circular section in a pot with a circular section. It becomes larger, the surface area of the sheathed heater becomes larger, and a large electric power can be input, so that heat can be easily transferred to water. For this reason, in the steam generator 50 of this embodiment, water can be heated rapidly.

    A steam suction part for sucking steam into the airflow flowing through the external circulation path 30 is formed in the upper part of the pot 51. The steam suction part is constituted by a steam suction ejector 34 formed so as to pass from one flat side surface of the pot 51 to the other flat side surface. A total of three vapor suction ejectors 34 are arranged in parallel and parallel to each other at the same height level at a predetermined interval.

    Each vapor suction ejector 34 includes an inner nozzle 34a and an outer nozzle 34b surrounding its discharge end. The steam suction ejector 34 extends in a direction intersecting the axis of the pot 51. In the embodiment, the crossing angle is a right angle, i.e. the vapor suction ejector 34 is horizontal. A duct 31 is connected to the inner nozzle 34a, and a duct 35 is connected to the outer nozzle 34b. The vapor suction ejector 34 is substantially the same height as the subcavity 40, and the duct 35 extends substantially horizontally. Thus, by connecting the steam suction part and the subcavity 40 linearly by the horizontal duct 35, the external circulation path 30 after passing the steam suction part can be made the shortest path.

    The external circulation path 30 is divided into three shunts including three steam suction ejectors 34 and a duct 35 subsequent thereto after the steam generator 50. For this reason, the pressure loss of the passage is reduced, the circulation steam amount can be increased, and the steam can be quickly mixed with the gas flowing through the external circulation path 30.

    As described above, the three steam suction ejectors 34 provided on the upper part of the pot 51 constitute a steam suction portion that occupies a flat space in the vertical cross-sectional shape and cover a wide area. The steam is sucked evenly and evenly, and the sucked steam is quickly sent out, so that the steam generation capability of the steam generator 50 is further improved. Further, since the three steam suction ejectors 34 are arranged in parallel with each other at the same height level, a large amount of steam can be transported even when there is no space in the height direction.

    Here, the direction of the fan casing 27 of the blower 25 will be described. The suction port 27a and the discharge port 27b of the fan casing 27 are perpendicular to each other. The position and angle of the fan casing 27 are set so that the discharge port 27b faces the direction of the steam suction ejector 34 that is the steam suction portion (see FIG. 11). A ventilation path is secured by the duct 31 between the discharge port 27 b and the vapor suction ejector 34. A ventilation path is also secured between the suction port 28 and the suction port 27a by a duct (not shown).

    With the above configuration, the gas sucked from the suction port 28 reaches the vapor suction ejector 34 through the shortest route as the air blowing route by the centrifugal fan. For this reason, the length of the external circulation path 30 is shortened, and the pressure loss at the time of ventilation reduces. Thereby, the energy input efficiency of the external circulation path 30 is improved. Further, since the heat radiation area of the external circulation path 30 is reduced, heat loss is also reduced. Together, the circulation efficiency of the external circulation path 30 is improved.

    The airflow discharged from the discharge port 27b has the highest flow velocity at the center as symbolized by the arrow group in FIG. 11, and the flow velocity decreases as it approaches the inner surface of the duct 31. This is due to the friction between the inner surface of the duct 31 and the gas. The portion of the airflow having the highest flow velocity is directed toward the center of the three steam suction ejectors 34 arranged side by side. Thereby, a direct communication relationship is established between the central steam suction ejector 34 and the discharge port 27b.

    Here, the “direct communication relationship” means that the gas discharged from the discharge port 27b reaches the vapor suction ejector 34 without detouring. This “direct communication relationship” is established not only for the central steam suction ejector 34 but also for the steam suction ejectors 34 on both sides thereof. This can be achieved by appropriately setting the width and angle of the portion of the duct 31 connected to the discharge port 27b. With this configuration, the variation in the air volume distributed to each steam suction ejector 34 is reduced, and steam can be sucked evenly from a wide range, so that the steam suction efficiency is improved.

    Returning to FIG. 4, the description will be continued. The bottom of the pot 51 is formed in a funnel shape, and the drain pipe 53 hangs down from there. A drain valve 54 is provided in the middle of the drain pipe 53. The lower end of the drain pipe 53 is bent toward the bottom of the heating chamber 20 with a predetermined angle gradient. A drain tank 14 disposed under the heating chamber 20 receives the end of the drain pipe 53. The drain tank 14 can be pulled out from the front side of the cabinet 10 to discard the water inside.

    Water is supplied to the pot 51 through a water supply channel. The water supply path is constituted by a water supply pipe 55 that connects the water tank 71 and the drain pipe 53. The water supply pipe 55 is connected to the drain pipe 53 at a location above the drain valve 54. The water supply pipe 55 drawn out from the connection point with the drain pipe 53 is once lifted into an inverted U shape and then lowered. A water supply pump 57 is installed in the middle of the descending portion. The water supply pipe 55 communicates with a horizontal funnel-shaped receiving port 58. A horizontal communication pipe 90 connects the water supply pipe 55 and the receiving port 58.

    A pot water level sensor 56 is disposed inside the pot 51. The pot water level sensor is positioned slightly higher than the steam generating heater 52.

    A rectangular parallelepiped water tank 71 is inserted into the water tank chamber 70. A water supply pipe 72 extending from the bottom of the water tank 71 is connected to the receiving port 58.

    When the water tank 71 is pulled out from the water tank chamber 70 and the water supply pipe 72 is separated from the receiving port 58, the water in the water tank 70 and the water on the water supply pipe 55 side will flow out as they are. In order to prevent this, coupling plugs 59 a and 59 b are attached to the receiving port 58 and the water supply pipe 72. In the state where the water supply pipe 72 is connected to the receiving port 58 as shown in FIG. 4, the coupling plugs 59 a and 59 b are connected to each other so that water can pass therethrough. When the water supply pipe 72 is pulled away from the receiving port 58, the coupling plugs 59a and 59b are closed, and the outflow of water from the water supply pipe 55 and the water tank 71 is stopped.

    A water supply pipe 55, a pressure detection pipe 91, and a pressure release pipe 92 are connected to the communication pipe 90 in order from the receiving port 58. A water level sensor 81 is provided at the upper end of the pressure detection pipe 91. The water level sensor 81 measures the water level in the water tank 71. The upper end of the pressure release pipe 92 bends horizontally and is connected to an exhaust path through which steam escapes from the heating chamber 20.

    The exhaust duct 93 and the container 93a constitute the exhaust path. The exhaust duct 93 constitutes the front part of the exhaust path, and the container 93a constitutes the rear part of the exhaust path. The exhaust duct 93 is longer in length. The exhaust duct 93 extends from the side wall of the heating chamber 20, gradually increases in height, and then is connected to the container 93a. The container 93a communicates with the outside of the machine, that is, outside the cabinet 10. The container 93a is made of synthetic resin, and has a larger cross-sectional area of the flow path than the exhaust duct 93.

    The inlet of the exhaust duct 93 is open toward the inside of the heating chamber 20. For this reason, if there is a liquid flowing down the exhaust duct 93 in the opposite direction to the exhaust, it enters the heating chamber 20 and accumulates at the bottom of the heating chamber. Since it can be seen at a glance that liquid has accumulated at the bottom of the heating chamber 20, the process will not be forgotten.

    At least a part of the exhaust duct 93 serves as a heat radiating portion 94. The heat radiating portion 94 is configured by a metal pipe having a plurality of heat radiating fins 95 on the outer surface.

    The container 93a passes beside the duct 31. In this place, a communication path is provided between the duct 31 and the container 93a. A communication duct 96 constitutes the communication path, and an electric damper 97 is provided therein. The damper 97 closes the communication duct 96 in a normal state.

    The highest portion of the water supply pipe 55 communicates with the container 93a through the overflow channel. What constitutes the overflow channel is an overflow pipe 98 having one end connected to the water supply pipe 55 and the other end connected to the upper end horizontal portion of the pressure release pipe 92. The height of the location where the pressure release pipe 92 is connected to the container 93a is the overflow level. The overflow level is set to be higher than the normal water level in the pot 51 and lower than the steam suction ejector 34.

    The container 93a has a complicated shape to receive the exhaust duct 93, the communication duct 96, the overflow pipe 98 and various ducts and pipes, but since it is made of synthetic resin, it can be seamless. For this reason, the problem of water leakage from the joint does not occur.

    The operation control of the steam cooker 1 is performed by a control device 80 shown in FIG. The control device 80 includes a microprocessor and a memory, and controls the steam cooker 1 according to a predetermined program. The control status is displayed on the display unit in the operation panel 13. An operation command is input to the control device 80 through various operation keys arranged on the operation panel 13. The operation panel 13 is also provided with a sound generating device for producing various sounds.

    In addition to the operation panel 13, the blower 25, the gas temperature raising heater 41, the damper 97, the steam generation heater 52, the drain valve 54, the pot water level sensor 56, the water supply pump 57, and the water level sensor 81 are connected to the control unit 80. The In addition, a temperature sensor 82 for measuring the temperature in the heating chamber 20 and a humidity sensor 83 for measuring the humidity in the heating chamber 20 are connected.

    The operation of the steam cooker 1 is as follows. First, the door 11 is opened, the water tank 71 is pulled out from the water tank chamber 70, and water is poured into the tank from a water supply port (not shown). The fully filled water tank 71 is pushed into the water tank chamber 70 and set at a predetermined position. After confirming that the tip of the water supply pipe 72 is firmly connected to the water inlet 58 of the water supply path, the article to be heated F is put into the heating chamber 20 and the door 11 is closed. Then, the power key in the operation panel 13 is pressed to turn on the power, and the operation key group provided in the operation panel 13 is also pressed to select the cooking menu and make various settings.

    When the water supply pipe 72 is connected to the receiving port 58, the water tank 71 and the pressure detection pipe 91 are in communication with each other, and the water level sensor 81 measures the water level in the water tank 71. If there is sufficient water to carry out the selected cooking menu, the controller 80 will initiate steam generation. If the amount of water in the water tank 71 is insufficient to perform the selected cooking menu, the control device 80 displays that fact on the operation panel 13 as a warning notification. Steam generation is not started until the shortage of water is resolved.

    When steam generation can be started, the water supply pump 57 starts operation and water supply to the steam generator 50 starts. At this time, the drain valve 54 is closed.

    Water accumulates from the bottom of the pot 51. When the pot water level sensor 56 detects that the water level has reached a predetermined level, the water supply is stopped there. Then, energization to the steam generating heater 52 is started. The steam generating heater 52 directly heats the water in the pot 51.

    Simultaneously with the energization of the steam generating heater 52, or when the water in the pot 51 reaches the predetermined temperature, the energization of the blower 25 and the gas temperature raising heater 41 is also started. The blower 25 sucks steam in the heating chamber 20 from the suction port 28 and sends the steam to the steam generator 50. Since the centrifugal fan 26 is used to send out the steam, a higher pressure can be generated compared to the propeller fan. In addition, since the centrifugal fan 26 is rotated at a high speed by a direct current motor, the flow velocity of the airflow is extremely fast.

    Since the flow velocity of the airflow is high in this way, the cross-sectional area of the flow path can be smaller than the flow rate. Therefore, the pipe forming the main body of the external circulation path 30 can have a circular cross section and a small diameter, and the surface area of the external circulation path 30 can be reduced compared to the case where the external circulation path 30 is formed by a duct having a rectangular cross section. For this reason, although hot steam passes through the inside, heat dissipation from the external circulation path 30 is reduced, and the energy efficiency of the steam cooker 1 is improved. Even when the external circulation path 30 is wound with a heat insulating material, the amount of the heat insulating material is small.

    At this time, the damper 97 closes the duct 96 leading from the duct 31 to the container 93a. The steam pumped from the blower 25 enters the steam suction ejector 34 from the duct 31, and further enters the subcavity 40 through the duct 35.

    When the water in the pot 51 boils, saturated steam at 100 ° C. and 1 atm is generated. Saturated steam enters the external circuit 30 from the steam suction ejector 34. Since the ejector structure is used, saturated steam is quickly sucked and joins the circulating airflow. Due to the ejector structure, no pressure is applied to the steam generator 50 and the release of saturated steam is not hindered.

    The steam exiting the steam suction ejector 34 flows into the subcavity 40 through the duct 35. The steam that has entered the subcavity 40 is heated to 300 ° C. by the gas temperature raising heater 41 and becomes superheated steam. A part of the superheated steam is ejected downward from the upper fusible hole 43. Another part of the superheated steam goes to the subcavity 44 through the duct 45 and is ejected laterally from the side air holes 46.

    14 and 15 show the flow of steam in a state where the object to be heated F is not put into the heating chamber 20. The steam blows downward from the upper blow hole 43 at a momentum reaching the bottom surface of the heating chamber 20. The steam that collides with the bottom surface of the heating chamber 20 turns to the outside. The steam begins to rise after exiting the downwardly flowing air stream. Since steam, especially superheated steam, is light, this direction change occurs naturally. As a result, convection is generated inside the heating chamber 20 as shown by the arrows in the drawing, in which the air is blown down at the center and rises outside the center.

    In order to form a clear convection, the arrangement of the upper fumaroles 43 is also devised. That is, as shown in FIG. 12, the arrangement of the upper blow holes 43 is dense at the center of the bottom panel 42 and sparse at the peripheral edge. As a result, the steam blowing force is weakened at the peripheral edge of the bottom panel 42 and does not hinder the rise of steam, so that convection appears more clearly.

    Steam is ejected sideways from the side fumarole 46. The steam meets the central portion of the heating chamber 20 and then mixes with the convection generated by the steam from the upper blow hole 43. Convective steam is sequentially sucked into the suction port 28. Then, after making a round of the route called the subcavity 40 from the external circulation path 30, the flow returns to the heating chamber 20. In this way, the steam in the heating chamber 20 repeats circulation such that it exits the external circulation path 30 and returns to the heating chamber 20.

    When the object to be heated F is placed in the heating chamber 20, the superheated steam heated to about 300 ° C. and ejected from the upper blow hole 43 collides with the object to be heated F and transfers heat to the object to be heated F. During this process, the steam temperature falls to about 250 ° C. The superheated steam that has contacted the surface of the object to be heated F releases latent heat when dew condensation occurs on the surface of the object to be heated F. This also heats the article F to be heated.

    As shown in FIGS. 4 and 5, after applying heat to the article F to be heated, the steam changes its direction to the outside and flows out of the air stream blowing down. As described above, since the steam is light, the vapor starts to rise after coming out of the down-flowing air current, and forms a convection as shown by an arrow inside the heating chamber 20. By this convection, while maintaining the temperature in the heating chamber 20, it is possible to keep the heated object F colliding with the superheated steam that has just been heated in the subcavity 40, and heat is rapidly and rapidly applied to the heated object F. Can be given.

    The steam ejected laterally from the side fumaroles 46 enters under the rack 22 from the left and right and meets under the object F to be heated. The direction of steam ejection from the side air holes 46 is tangential to the surface of the object to be heated F. Thus, when the steam from the left and right meet, the steam does not escape straight and the object to be heated does not escape. It stays under F and overflows. For this reason, the same effect as when the steam is sprayed in the normal direction of the surface of the object to be heated F is generated, and the heat of the steam is reliably transmitted to the lower surface portion of the object to be heated F.

    As described above, the object to be heated F is cooked in the same manner as the upper surface portion up to the portion where the steam from the upper blow hole 43 does not hit by the steam from the side blow hole 46. Thereby, the cooking result with a good appearance without unevenness can be obtained. Moreover, since the to-be-heated material F receives heat equally from the whole surface, it is fully heated to a center part for a short time.

    The vapor from the side fumaroles 46, which was initially about 300 ° C., falls to about 250 ° C. after it hits the object F to be heated, and heat is transferred to the object F in the process. Further, when condensation is formed on the surface of the object to be heated F, latent heat is released to heat the object to be heated F.

    The steam from the side nozzle holes 46 gives heat to the lower surface of the article to be heated F, and then joins the convection generated by the steam from the upper nozzle holes 43. Convective steam is sequentially sucked into the suction port 28. Then, after making a round of the route called the subcavity 40 from the external circulation path 30, the flow returns to the heating chamber. In this way, the steam in the heating chamber 20 repeats circulation such that it exits the external circulation path 30 and returns to the heating chamber 20.

    As time passes, the amount of steam in the heating chamber 20 increases. The surplus steam is discharged outside the machine through the exhaust passage. If the steam goes out of the cabinet 10 as it is, dew condensation occurs on the surrounding wall surface and mold occurs. However, since there is a heat radiating portion 94 in the middle of the exhaust duct 93, the steam is deprived of heat while passing through the exhaust duct 93 and is condensed on the inner surface of the exhaust duct 93. Therefore, the amount of steam that goes out of the cabinet 10 is small and does not cause a serious problem. Water condensed on the inner surface of the exhaust duct 93 flows down in the direction opposite to the direction of exhaust and enters the heating chamber 20. This water can be treated together when the water collected in the tray 21 is treated.

    Since the container 93a communicating with the outside of the machine is formed with a large flow path area, the steam blowing speed becomes slow. Therefore, the object outside the aircraft is not damaged by the steam hitting it vigorously.

    The side fumarole 46 is separated from the subcavity 40 and is disadvantageous compared to the upper fumarole 43 in terms of vapor ejection. However, since the area sum of the left and right side air holes 46 is made larger than the area sum of the upper air holes 43, a sufficient amount of steam is guided to the side air holes 46, and the upper and lower surfaces of the object F to be heated. The unevenness of heating is reduced.

    Since the object to be heated F is heated while circulating the steam in the heating chamber 20, the energy efficiency of the steam cooker 1 is high. Then, the superheated steam from above is ejected downward from the plurality of upper air holes 43 distributed over the entire surface of the bottom panel 42 of the subcavity 40, so that almost the entire heated object F is converted into steam from above. It will be wrapped up. Combined with the collision of the superheated steam with the object to be heated F and the large area of the collision, the heat contained in the superheated steam is quickly and efficiently transmitted to the object to be heated F. Further, the steam that has entered the subcavity 40 is heated by the gas temperature raising heater 41 and expands, whereby the momentum of jetting increases and the collision speed with the heated object F increases. Thereby, the to-be-heated material F is heated more rapidly.

    Since the centrifugal fan 26 can generate a higher pressure than the propeller fan, the jet output from the upper blow hole 43 can be increased. As a result, the superheated steam can be ejected with a momentum reaching the bottom surface of the heating chamber 20, and the heated object F can be heated strongly. The centrifugal fan 26 is rotated at a high speed by a direct current motor and blows powerfully, so that the above-mentioned effect appears more remarkably.

    In addition, the strong blowing power of the blower 25 greatly helps to quickly exhaust air from the exhaust port 32 when the door 11 is opened to take out the article F to be heated.

    Since the bottom panel 42 of the subcavity 40 has a dark upper surface, it absorbs the radiant heat emitted from the gas heating heater 41 well. Radiant heat absorbed by the bottom panel 42 is radiated and radiated to the heating chamber 20 from the bottom surface of the bottom panel 42, which is also dark. For this reason, the temperature rise of the subcavity 40 and its outer surface is suppressed, safety is improved, and the radiant heat of the gas temperature raising heater 41 is transmitted to the heating chamber 20 through the bottom panel 42 so that the heating chamber 20 can be heated more efficiently. It is done. The planar shape of the bottom panel 42 may be circular, or may be a rectangle similar to the planar shape of the heating chamber 20. Further, as described above, the ceiling wall of the heating chamber 20 may also be used as the bottom panel of the subcavity 40.

    When the object to be heated F is meat, the oil may dripping when the temperature rises. If the object to be heated F is a liquid contained in a container, it may boil and partially spill. What has dripped or spilled is received by the tray 21 and waits for processing after cooking is completed.

    If steam is continuously generated by the steam generator 50, the water level in the pot 51 is lowered. When the pot water level sensor 56 detects that the water level has dropped to a predetermined level, the control device 80 restarts the operation of the water supply pump 57. The water supply pump 57 sucks the water in the water tank 71 and replenishes the pot 51 with the evaporated water. When the pot water level sensor 56 detects that the water level in the pot 51 has recovered to a predetermined level, the control device 80 stops the operation of the water supply pump 57 again.

    If the pot water level sensor 56 or the feed water pump 57 fails, or if the water pump 57 does not stop operating due to other reasons, the water level in the pot 51 continues to rise above a predetermined level. When the water level reaches the overflow level, the water sent from the feed pump 57 overflows from the overflow pipe 98 to the container 93a and flows into the exhaust duct 93. For this reason, the water in the pot 51 does not enter the external circulation path 30 from the steam suction ejector 34. Water entering the exhaust duct 93 flows into the heating chamber 20.

    The container 93a has a large capacity because it has a large flow path area. Therefore, even if a large amount of water overflows, it can be received with sufficient margin and slowly discharged from the exhaust duct 93.

    After cooking is completed, the control device 80 displays a message to that effect on the operation panel 13 and sounds a signal. A user who knows the end of cooking by sound and display opens the door 11 and takes out the article F to be heated from the heating chamber 20.

    When the door 11 is about to open, the control device 80 switches the open / close state of the damper 97 and opens the duct 96. Then, the airflow flowing in the external circulation path 30 passes from the duct 96 to the container 93a, and there is almost no part of turning to the steam generator 50. For this reason, the amount of steam flowing into the subcavity 40 is reduced, and the steam jets from the upper and lower jet holes 43 and 46 are extremely weak, if any. Therefore, the user can safely take out the object to be heated F without incurring a burn on the face or hands. The damper 97 opens the duct 96 while the door 11 is open.

    The duct 96 and the container 93a are not as hot as the external circulation path 30 because the steam is not circulated. Therefore, the vapor flowing from the external circulation path 30 is condensed when it contacts the duct 96 and the inner wall of the container 93a. Water generated by the condensation flows down through the duct 93 and enters the heating chamber 20. This water can be treated after the cooking is finished together with the water accumulated at the bottom of the heating chamber 20 for other reasons.

    Since the container 93a is formed with a large flow path area, the internal surface area is large. Therefore, a considerable part of the steam that has entered from the duct 96 is condensed here, and the amount of steam released to the outside can be reduced.

    If exhausting is performed by starting the blower 25 that is stopped, a time lag occurs until the steady blower state is reached, but in this embodiment, the blower 25 is already in operation and the time lag is zero. is there. Further, since the circulating airflow that has flowed around the heating chamber 20 and the external circulation path 30 becomes the exhaust airflow from the container 93a as it is, there is no time lag for changing the direction of the airflow. Thereby, the vapor | steam in the heating chamber 20 is discharged | emitted without delay, and the time until opening of the door 11 is attained can be shortened.

    The situation that the user is about to open the door 11 can be notified to the control device 80 as follows, for example. That is, a latch for keeping the door 11 closed is provided between the cabinet 10 and the door 11, and a latch lever for unlocking the latch is provided so as to be exposed from the handle 12. A switch that opens and closes in response to the movement of the latch or the latch lever is arranged inside the door 11 or the handle 12, and when the user performs an unlocking operation by grasping the handle 12 and the latch lever, the switch switches to the control device 80. Make sure the signal is sent.

    In the above embodiment, the configuration in which the steam in the heating chamber 20 is returned from the external circulation path 30 to the heating chamber 20 again through the subcavity 40 is adopted, but a configuration different from this is also possible. For example, new steam may be constantly supplied to the subcavity 40, and the steam overflowing from the heating chamber 20 may be continuously discharged from the exhaust path.

  In addition, various modifications can be made without departing from the spirit of the invention.

    INDUSTRIAL APPLICABILITY The present invention can be used for all cookers that cook with steam, whether for home use or business use.

External perspective view of steam cooker External perspective view of the heating chamber with the door open Front view with the heating chamber door removed Basic structure of internal mechanism Basic structure of the internal mechanism viewed from the direction perpendicular to FIG. Top view of heating chamber Vertical section of steam generator Horizontal sectional view taken along line AA in FIG. Horizontal sectional view taken along line BB in FIG. Front view of steam generator Vertical sectional view of the blower Top view of bottom panel of subcavity Control block diagram The same basic structure as FIG. 4 but showing a different state from FIG. The same basic structure as FIG. 5 but showing a different state from FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steam cooker 20 Heating chamber 25 Blower 26 Centrifugal fan 27 Fan casing 27a Inlet 27b Outlet 28 Inlet 30 External circulation path 31 Duct 34 Steam suction ejector 35 Duct 40 Subcavity 50 Steam generating apparatus F

Claims (5)

In a steam cooker provided with a heating chamber for storing an object to be heated and an external circulation path for sucking the gas in the heating chamber and returning the sucked gas to the heating chamber again,
The external circulation path is disposed at a suction port formed on one side wall of the heating chamber and at a position close to the outer surface of the one side wall and communicated with the suction port, and gas is supplied from the suction port. A blower that sucks in and forms an airflow that flows in the external circulation path, and is also disposed at a position that is close to the outer surface of the one side wall and that can supply steam to the airflow that flows in the external circulation path. A steam cooker comprising a steam generator for supplying steam to the airflow flowing through the external circulation path ,
The external circulation path after passing the steam generator is connected to a subcavity provided adjacent to the heating chamber,
The sub-cavity has a built-in gas heating heater that heats the steam flowing through the external circulation path, and a hole is formed in the bottom panel of the sub-cavity, and steam is supplied into the heating chamber through the hole. Steam cooker characterized by being made. 2. The steam cooker according to claim 1, wherein one or both of the upper surface and the lower surface of the bottom panel is dark.   The steam cooker according to claim 1 or 2, wherein the steam generating device includes a steam suction portion at an upper portion thereof, and the external circulation path forms an airflow passing through the steam suction portion. The steam generator has a steam suction part at the top, and the external circulation path forms an air flow passing through the steam suction part, and the steam suction part is provided at substantially the same height as the subcavity. The steam cooker according to claim 1 or 2, characterized in that .   The suction port is disposed at the upper corner of the one side wall, and the blower device includes a centrifugal fan, and the fan casing of the centrifugal fan is disposed such that the discharge port faces the direction of the vapor suction unit. 5. The steam cooker according to claim 3 or claim 4, wherein the steam cooker is provided.

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