JP2008032268A - Heating cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating cooker capable of preventing defective cooking. <P>SOLUTION: In this heating cooker 1 comprising a steam container 51 for storing water supplied from water supply means 55, 57, a heating means 52 for heating the water in the steam container 51, and a water level detecting portion 81 for detecting a water level in the steam container 51, and cooking a heated object by the steam generated by the steam container 51, the water level detecting portion 81 has a GND electrode 81a kept at reference potential, a detection electrode 81b made conductive to the GND electrode 81a through the water supplied to the steam container 51, and a partitioning plate 81c partitioning the GND electrode 81a and the detection electrode 81b, and the GND electrode 81a, the detection electrode 81b and the partitioning plate 81c are suspended from the ceiling of the water level detecting portion 81. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a heating cooker that cooks an object to be heated by jetting steam into a heating chamber.

  An example of a conventional cooking device is disclosed in Patent Document 1. This heating cooker uses superheated steam as a heating medium, and an object to be heated is placed on a tray placed in a heating chamber. A water tank is arranged on the side of the heating chamber, and water is supplied from the water tank to the steam generator through a water supply channel. The steam generator generates steam from the supplied water and sends it to the steam temperature raising device. The steam temperature raising device further heats the steam to generate superheated steam, and jets the superheated steam into the heating chamber to cook the object to be heated.

  The steam generator has a pot that is supplied with water from a water tank via a water supply channel, and is provided with a water level detection unit that detects the water level in the pot. When the water level of the pot is lowered, water is supplied into the pot by the detection of the water level detection unit.

  The configuration of the water level detection unit is disclosed in detail in Patent Document 2, for example. This water level detection part is provided with a GND electrode and a detection electrode suspended from the ceiling in the container. The GND electrode is maintained at a reference potential, and when the water is supplied into the container, the GND electrode and the detection electrode become conductive. Thereby, it is detected that the water level in the container is higher than the predetermined water level. Further, when the conduction between the GND electrode and the detection electrode is interrupted, it is detected that the water level in the container is lower than the predetermined water level.

On the other hand, household cooking devices that can perform steam cooking with the steam generator as described above have recently attracted attention. However, miniaturization of household cooking devices is required. For example, if the size of the casing is the same, it is preferable to ensure a large size (capacity) of the heating chamber, and if the size of the heating chamber is the same, the size of the casing is preferably small. For this reason, it is necessary to reduce the size of necessary parts, and the water level detection unit is necessarily required to be downsized.
Japanese Patent Laid-Open No. 2005-61816 JP 2000-266302 A

  However, according to the heating cooker described in Patent Document 2, since the water in the pot is heated, there is a case where the GND electrode and the detection electrode are electrically connected at the attachment portion due to dew condensation generated on the ceiling of the pot. For this reason, even if the water level in the pot is lowered, water supply may be stopped or water supply may not be performed due to conduction between the GND electrode and the detection electrode, and normal water supply may not be performed. In particular, as the distance between the GND electrode and the detection electrode becomes shorter due to the downsizing of the water level detection unit or the like, conduction due to condensation between the GND electrode and the detection electrode is more likely to occur.

  An object of this invention is to provide the heating cooker which can perform water supply to a pot more normally.

In order to achieve the above object, the present invention includes an evaporation container that stores water supplied from a water supply means, a heating means that heats water in the evaporation container, and a water level detection unit that detects the water level of the evaporation container. In a heating cooker that cooks an object to be heated using steam generated in the evaporation container,
The water level detection unit includes a GND electrode that is maintained at a reference potential, a detection electrode that is electrically connected to the GND electrode through water supplied to the evaporation container, and a partition that partitions the GND electrode and the detection electrode. The GND electrode, the detection electrode, and the partition plate are suspended from the ceiling of the water level detection unit.

  According to this configuration, when cooking is started, water is supplied into the evaporation container, and the water level detection unit detects the presence of water by conduction between the GND electrode and the detection electrode partitioned by the partition plate hanging from the ceiling. The water in the evaporation container is heated to generate steam, and the generated steam is supplied to the heating chamber to cook the object to be heated. When the water level of the evaporation container is lowered, conduction between the GND electrode and the detection electrode is interrupted, and water supply is performed. When dew condensation occurs on the ceiling of the water level detection unit, conduction between the GND electrode and the detection electrode due to dew condensation is avoided by the partition plate. The water level detection unit may be provided in the evaporation container or in another detection container communicating with the evaporation container.

  Moreover, in the heating cooker according to the present invention, the lower end of the partition plate is disposed above the lower end of the GND electrode and the lower end of the detection electrode in the heating cooker configured as described above. It is preferable to do. According to this configuration, when the lower end of the detection electrode is disposed above the lower end of the GND electrode, the lower end of the partition plate is disposed above the lower end of the detection electrode. At this time, conduction between the GND electrode and the detection electrode is interrupted at a water level lower than the lower end of the detection electrode. Moreover, when the lower end of the GND electrode is disposed above the lower end of the detection electrode, the lower end of the partition plate is disposed above the lower end of the GND electrode. At this time, the conduction between the GND electrode and the detection electrode is interrupted at a water level lower than the lower end of the GND electrode.

  Moreover, in the heating cooker according to the present invention, the lower end of the partition plate is 20 mm or more above the lower end of the GND electrode and the lower end of the detection electrode in the heating cooker having the above configuration. It is preferable to arrange in. When the lower end of the detection electrode is disposed above the lower end of the GND electrode, the lower end of the partition plate is disposed 20 mm or more above the lower end of the detection electrode. When the lower end of the GND electrode is disposed above the lower end of the detection electrode, the lower end of the partition plate is disposed 20 mm or more above the lower end of the GND electrode.

  Moreover, in the cooking device according to the present invention, in the cooking device configured as described above, the GND electrode and the detection electrode are formed in a thin plate shape, and the surfaces forming the thicknesses of the GND electrode and the detection electrode are opposed to each other. It is preferable.

  Moreover, in the cooking device according to the present invention, it is preferable that the partition plate is tapered in the cooking device configured as described above.

  Moreover, in the cooking device according to the present invention, in the cooking device configured as described above, it is preferable that the water level detection unit is arranged in the evaporation container.

  Moreover, in the heating cooker according to the present invention, in the heating cooker configured as described above, the heating means includes a spiral heater disposed in the evaporation container, and the spiral shape from the ceiling portion of the evaporation container. It is preferable that a cylindrical isolation wall extending in the heater is provided and the water level detection unit is disposed in the isolation wall. According to this configuration, the water in the evaporation container is heated by the heater disposed outside the isolation wall, and the water level of the evaporation container is detected by the GND electrode and the detection electrode disposed inside the isolation wall.

  According to the present invention, since the water level detection unit has the partition plate that partitions the GND electrode and the detection electrode suspended from the ceiling, it prevents conduction between the GND electrode and the detection electrode due to condensation generated on the ceiling of the water level detection unit. can do. Thereby, the detection accuracy of a water level detection part improves, and water supply is more reliably performed when a water level falls rather than a predetermined water level.

  Further, if the lower end of the partition plate is disposed above the lower end of the GND electrode and the lower end of the detection electrode, the surface tension is lower at the lower water level than the lower end of the GND electrode and the lower end of the detection electrode. Therefore, it is possible to reduce the bridge of water between the GND electrode and the partition plate and between the detection electrode and the partition plate. Therefore, erroneous detection of the water level detection unit can be prevented and detection accuracy can be further improved.

  In addition, if the lower end of the partition plate is disposed 20 mm or more above the lower end of the GND electrode and the lower end of the detection electrode, erroneous detection of the water level detection unit due to surface tension can be more reliably prevented. Can do.

  Further, if the surfaces forming the thickness of the GND electrode and the detection electrode formed in a thin plate are opposed to each other, water is bridged between the GND electrode and the partition plate and between the detection electrode and the partition plate by surface tension. Can be further reduced.

  In addition, if the partition plate is tapered, it is possible to further reduce water from being bridged between the GND electrode and the partition plate and between the detection electrode and the partition plate due to surface tension.

  Further, if the water level detection unit is arranged in the evaporation container, the evaporation container and the water level detection unit are combined into one, and the size can be reduced.

  In addition, if the water level detection unit is disposed in a cylindrical isolation wall extending from the ceiling of the evaporation container into the spiral heater, the steam generation unit that generates steam can be downsized. In addition, foaming due to boiling of water in contact with the heater can be hardly transmitted to the water level detection unit, and the detection accuracy of the water level detection unit can be improved.

  Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 are a front view and a side view showing the heating cooker according to the first embodiment. The heating cooker 1 cooks an object to be heated with a heating medium made of superheated steam. The heating cooker 1 includes a rectangular parallelepiped cabinet 10. A door 11 is provided in front of the cabinet 10.

  The door 11 is pivotally supported in a vertical plane with the lower end as a center, and a handle 12 for opening and closing the door 11 is provided at the upper part. A central portion 11C of the door 11 is provided with a transmission portion 11a (see FIG. 3) in which heat-resistant glass is fitted to visually recognize the inside. A left side portion 11L and a right side portion 11R provided with metal decorative plates on the surface are symmetrically arranged on the left and right sides of the central portion 11C. An operation panel 13 is provided on the right side 11 </ b> R of the door 11.

  FIG. 3 shows a front view of the heating cooker 1 with the door 11 opened. The door 11 is rotated when the handle 12 is gripped and pulled forward, and the posture of the door 11 can be changed by 90 ° from a vertical closed state to a horizontal open state. 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, and a water tank 71 for storing water for generating steam is stored therein. No opening is provided at a location corresponding to the right side portion 11R of the door 11, but a control board (not shown) is disposed inside.

  The heating chamber 20 is formed in a substantially rectangular parallelepiped, and the entire front side facing the door 11 is an opening 20d for taking in and out the article to be heated F (see FIG. 8). The opening 20d is opened and closed by the rotation of the door 11. The wall surface of the heating chamber 20 is formed of a stainless steel plate, and the outer peripheral surface of the heating chamber 20 is provided with a heat insulation measure.

  FIG. 4 is a front view showing details in the heating chamber 20. On the side wall of the heating chamber 20, a plurality of tray support portions 20 b and 20 c are provided at different heights. The upper tray support part 20 b is provided below the reflection part 68. A stainless steel plate receiving tray 21 is locked to one or more of the tray supporting portions 20b and 20c. A stainless steel wire rack 22 on which the object to be heated F is placed is placed on the tray 21.

  When cooking with superheated steam, the tray 21 is installed in the upper tray support portion 20b. Thereby, superheated steam can be guide | induced to the lower surface of the to-be-heated material F by reflection of the reflection part 68 so that it may mention later. The tray 21 may be installed on the upper and lower tray support portions 20b and 20c. Thereby, many to-be-heated materials F can be cooked at once. At this time, the tray 21 arranged in the tray support portion 20b is formed to have air permeability, and superheated steam is supplied to the lower tray 21.

  The back wall on the back side of the heating chamber 20 is provided with an intake port 28 at a substantially central portion in the left-right direction, and an exhaust port 32a is provided at the lower left portion. The reflection part 68 is recessed in the both side walls of the heating chamber 20, and the surface is formed by a curved surface. Superheated steam jetted laterally from a jet cover 61 (described later) toward the reflecting portion 68 is reflected by the reflecting portion 68 and guided below the object to be heated F (see FIG. 8).

  An ejection cover 61 made of a stainless steel plate that ejects superheated steam is attached to the top surface of the heating chamber 20. An illumination device 69 that illuminates the inside of the heating chamber 20 is provided on the front side of the right side portion of the ejection cover 61.

  5, 6, and 7 show a perspective view, a plan view, and a side sectional view of the main part of the ejection cover 61. The ejection cover 61 is formed in a substantially hexagonal shape in which both front corners are chamfered with respect to a rectangle in plan view. The ejection cover 61 is finished in a dark color by surface treatment such as painting on both the upper and lower surfaces. Thereby, the radiation heat of the steam heater 41 (see FIG. 8) is absorbed and radiated from the lower surface of the ejection cover 61 to the heating chamber 20.

  For this reason, while suppressing the temperature rise of the vapor | steam temperature rising apparatus 40 (refer FIG. 8) and its outer surface, safety improves and the heating efficiency of the heating chamber 20 improves. You may form the ejection cover 61 with the metal raw material which changes to a dark color by repeated use. Moreover, you may form the ejection cover 61 with a dark-colored ceramic molded product.

  A mounting portion 62 that is in close contact with the top surface of the heating chamber 20 is provided on the peripheral portion of the ejection cover 61. The mounting portion 62 is provided with a plurality of screw holes 62a for screwing the ejection cover 61 with screws. A flat surface portion 63 that is continuous through an inclined surface 64 that is inclined with respect to the attachment portion 62 is provided in the central portion of the ejection cover 61.

  The inclined surface 64 includes a side surface portion 64a, a front surface portion 64b, a corner portion 64c, and a back surface portion 64d. The side surface portion 64 a is formed to extend in a direction parallel to the side wall of the heating chamber 20. The front surface portion 64 b is provided on the front surface side of the ejection cover 61 and extends in a direction parallel to the door 11. The corner portion 64c connects the side surface portion 64a and the front surface portion 64b obliquely. The back surface portion 64 d is provided on the back surface side of the ejection cover 61 and is formed to extend in a direction parallel to the back wall of the heating chamber 20.

  The planar portion 63 and the inclined surface 64 are provided with a plurality of jet holes 65, 66, 67. A cylindrical guide portion 65 a perpendicular to the flat surface portion 63 is formed at the periphery of the air outlet 65 provided in the flat surface portion 63. Cylindrical guide portions 66 a and 67 a that are perpendicular to the inclined surface 64 are formed at the peripheral edges of the air outlets 66 and 67 provided on the inclined surface 64. Thereby, an airflow can be guided to the axial direction of the jet openings 65, 66, and 67.

  The air inlets 66 and 67 of the inclined surface 64 are larger in diameter than the air outlets 65 of the flat surface portion 63 and are provided with a high density. Further, the blast holes 66 of the side surface portion 64a of the inclined surface 64 are provided at a higher density than the blast port 67 of the front surface portion 64b and the corner portion 64c. In addition, the back surface part 64d of the inclined surface 64 is not provided with the fumarole.

  FIG. 8 shows a schematic structure of the inside of the heating cooker 1. In the figure, the heating chamber 20 is viewed from the side. As shown in FIG. 3 described above, the water tank 71 is disposed on the left side of the heating chamber 20 and communicates with the tank water level detection container 91 via the joint portion 58. Thereby, the water tank 71 is detachable with respect to the cabinet 10 (refer FIG. 2).

  The tank water level detection container 91 is provided with a water level sensor 56. The water level sensor 56 has a plurality of electrodes, and detects the water level by conduction between the electrodes. In this embodiment, the water level is detected in three stages by the GND electrode and the three detection electrodes. When the water level of the water tank 71 falls below a predetermined water level as detected by the water level sensor 56, a notification is given to encourage water supply.

  In the tank water level detection container 91, a water supply path 55 extends to the bottom and is immersed. The water supply passage 55 is provided with a water supply pump 57 in the middle of the route, and is connected to the steam generator 50. The steam generator 50 has a cylindrical pot 51 (evaporation container) whose axial direction is vertical, and water is supplied from the water tank 71 to the pot 51 by driving a water supply pump 57. Accordingly, the water supply pump 57 and the water supply passage 55 constitute water supply means for supplying water to the pot 51.

  FIG. 9 is a front sectional view showing the steam generator 50. The pot 51 is formed into a cylindrical shape from metal, synthetic resin, ceramic, or a combination of these different materials, and has heat resistance. In the pot 51, a steam generating heater 52 comprising a spiral sheathed heater as a heating means is immersed. The water in the pot 51 is heated by energization of the steam generating heater 52, and steam is generated. Thus, the pot referred to in the present embodiment refers to a container (evaporation container) for boiling water in the interior to generate steam.

  In the pot 51, there is provided a water level detection chamber 51b in which the steam generating heater 52 is isolated by a cylindrical isolation wall 51a extending from the upper surface into the spiral steam generating heater 52. The isolation wall 51a is formed to have a gap with respect to the bottom surface of the pot 51, and the inside and outside of the water level detection chamber 51b communicate with each other and are maintained at the same water level. Moreover, the water supply path 55 (refer FIG. 8) has the water supply port 55a in an open end, and the water supply port 55a opens to the upper part of the water level detection chamber 51b, and discharges water. This water cools the water in the water level detection chamber 51b and suppresses the water temperature in the water level detection chamber 51b from rising above the water temperature outside the water level detection chamber 51b. Therefore, boiling does not easily occur in the water level detection chamber 51b.

  A pot water level detection unit 81 (water level detection unit) that detects the water level in the pot 51 is provided in the water level detection chamber 51b. The pot water level detection unit 81 includes a ceiling portion formed from the top surface of the water level detection chamber 51b, and includes a pot GND electrode 81a (GND electrode) and a pot detection electrode 81b (detection electrode) suspended from the ceiling portion.

  The pot GND electrode 81 a and the pot detection electrode 81 b are supported by a boss portion 51 c protruding from the upper surface side and the lower surface side of the ceiling portion of the pot water level detection unit 81. As a result, the pot GND electrode 81a and the pot detection electrode 81b are supported in an increased area and prevented from falling off.

  The pot GND electrode 81a is maintained at a reference potential (for example, 0 V). When water is supplied to the pot 51, the pot GND electrode 81a and the pot detection electrode 81b are electrically connected by water. Therefore, it is possible to detect that the pot 51 has reached the predetermined water level L or that there is more water than the water level L by the conduction between the pot GND electrode 81a and the pot detection electrode 81b. When the conduction between the pot GND electrode 81a and the pot detection electrode 81b is cut off, it can be detected that the water is less than the water level L.

  In addition, the water supply operation | movement during cooking of this embodiment is performed as follows. As the steam is generated in the pot 51, the water level in the pot 51 decreases. When a predetermined time elapses after continuity between the pot GND electrode 81a and the pot detection electrode 81b is not performed due to a decrease in the water level, the water supply pump 57 is driven. As a result, water is supplied from the water tank 71 to the pot 51.

  Further, when the pot GND electrode 81a and the pot detection electrode 81b are electrically connected, the water supply is stopped. In other words, when a predetermined time elapses after the water level in the water level detection chamber 51b becomes less than the water level L, the water supply pump 57 is driven, and when the water level becomes equal to or higher than the water level L, the water supply pump 57 is stopped to stop water supply.

  In the pot water level detection unit 81, a partition plate 81c that divides the pot GND electrode 81a and the pot detection electrode 81b is suspended from the ceiling. Both sides of the partition plate 81c are connected to the isolation wall 51a, and the upper part of the water level detection chamber 51b is separated into two. Since the water in the water level detection chamber 51b is isolated by the isolation wall 51a, it is harder to warm than the water outside the water level detection chamber 51b. However, since the temperature of the water in the water level detection chamber 51 b is raised, water vapor is generated, and the water vapor contacts with the ceiling of the pot water level detection unit 81 to cause dew condensation.

  The partition plate 81c can prevent conduction between the pot GND electrode 81a and the pot detection electrode 81b due to condensation on the ceiling. Thereby, the erroneous detection of the pot water level detection part 81 can be prevented. Accordingly, when the water level of the evaporation container (pot 51) is lower than the predetermined water level, water can be supplied more reliably. Moreover, the possibility that the water in the pot 51 disappears due to erroneous detection of the pot water level detection unit 81 and cooking failure occurs can be reduced.

  The lower end of the partition plate 81c is disposed above the lower ends of the pot GND electrode 81a and the pot detection electrode 81b. FIG. 10 shows a case where the lower end of the partition plate 81c is disposed below the lower ends of the pot GND electrode 81a and the pot detection electrode 81b. As shown in the figure, since the steam generator 50 is downsized, the pot GND electrode 81a, the pot detection electrode 81b, and the partition plate 81c approach each other. In the present embodiment, the distance between the partition plate 81c and the pot GND electrode 81a and the distance between the partition plate 81c and the pot detection electrode 81b are about 3 mm.

  For this reason, when the vapor pressure rises outside the water level detection chamber 51b or the water surface S rises due to vibration or the like, the surface tension causes the space between the partition plate 81c and the pot GND electrode 81a, or between the partition plate 81c and the pot detection electrode. There is a case where water is bridged with 81b (hereinafter, this state is referred to as “bridge”). When the bridge on the pot GND electrode 81a side and the bridge on the pot detection electrode 81b side are connected, the pot GND electrode 81a and the pot detection electrode 81b are conducted even when the water level is lower than the water level L. As a result, erroneous detection of the pot water level detection unit 81 occurs.

  In addition, even if the water level further decreases from this state, the bridge may continue to be generated. If such a state continues, water may be lost from the pot 51, and so-called emptying may occur.

  In the present embodiment, the reason why the water level in the water level detection chamber 51b increases due to the increase in vapor pressure outside the water level detection chamber 51b is that the water level detection chamber 51b is open to the atmosphere. Specifically, since the upper part of the tank water level detection container 91 communicating with the water level detection chamber 51b via the overflow pipe 98 is opened, the water level detection chamber 51b is also opened to the atmosphere. Accordingly, when the vapor pressure increases outside the water level detection chamber 51b, the water level outside the water level detection chamber 51b is pushed by the vapor pressure and decreases. As a result, the water level in the water level detection chamber 51b rises.

  When the lower end of the partition plate 81c is disposed above the lower ends of the pot GND electrode 81a and the pot detection electrode 81b as in the present embodiment, the partition plate 81c and the water surface in the water level detection chamber 51b come into contact with each other. It is possible to reduce the possibility of occurrence of a bridge. Thereby, possibility that the false detection of the pot water level detection part 81 will generate | occur | produce can be reduced.

  Table 1 shows the results of examining the occurrence of bridges due to the arrangement of the partition plates 81c. According to this, when the distance between the lower end of the partition plate 81c and the water surface is smaller than 20 mm, a bridge is easily generated. When the distance between the lower end of the partition plate 81c and the water surface is 20 mm or more, the bridge hardly occurs.

  When the water level is lower than the water level L, it is necessary to avoid the bridge. However, when the water level is higher than the water level L, the pot water level detection unit 81 does not detect erroneously even if a bridge occurs. Therefore, the distance H (see FIG. 9) between the lower end of the partition plate 81c and the lower ends of the pot GND electrode 81a and the pot detection electrode 81b is preferably 20 mm or more. When the position of the lower end of the pot GND electrode 81a is different from the position of the lower end of the pot detection electrode 81b, the lower end of the partition plate 81c may be disposed further upward than the one disposed above them.

  The pot GND electrode 81a and the pot detection electrode 81b are formed in a thin plate shape. FIG. 11 is a top cross-sectional view showing the main part of the pot water level detection unit 81. The pot GND electrode 81a and the pot detection electrode 81b are arranged on a substantially straight line in the direction of the width W with the surfaces f1 and f2 forming the thickness t facing each other. Thereby, the opposing area of the partition plate 81c and the pot GND electrode 81a and the opposing area of the partition plate 81c and the pot detection electrode 81b can be reduced. Therefore, the occurrence of bridges can be further reduced.

  Moreover, the partition plate 81c is formed to be tapered so that the lower end is narrowed. For this reason, at the lower end of the partition plate 81c close to the water surface, the distance between the partition plate 81c and the pot GND electrode 81a and the distance between the partition plate 81c and the pot detection electrode 81b can be increased. Therefore, the occurrence of bridges can be further reduced.

  Further, the lower surface side of the boss portion 51c that supports the pot GND electrode 81a and the pot detection electrode 81b is formed on an inclined surface that descends toward the pot GND electrode 81a and the pot detection electrode 81b. Thereby, the dew condensation water which generate | occur | produced in the ceiling part of the pot water level detection part 81 is guide | induced to each electrode, and flows down along an electrode. Thereby, it is possible to make it difficult for condensation to accumulate on the ceiling of the pot water level detection unit 81.

  Moreover, when dew condensation occurs on the outside of the steam generator 50, the dew condensation may be connected and the pot GND electrode 81 a and the pot detection electrode 81 b may be conducted. By the boss part 51c protruding to the upper surface side of the ceiling part of the pot water level detection part 81, the dew condensation generated on the outside side of the steam generating device 50 exceeds the height of the boss part 51c and the pot GND electrode 81a and the pot detection The electrode 81b does not conduct. Thereby, possibility that the false detection of the pot water level detection part 81 will generate | occur | produce can be reduced.

  In addition, the upper surface side of the boss portion 51c is formed on an inclined surface in which the sides away from the pot GND electrode 81a and the pot detection electrode 81b are lowered. Thereby, the dew condensation generated on the outside of the steam generator 50 flows down the slope, and the conduction between the pot GND electrode 81a and the pot detection electrode 81b can be further reduced.

  A partition plate may be provided between the pot GND electrode 81a and the pot detection electrode 81b on the outside of the steam generating device 50. Thereby, even if dew condensation occurs on the outside of the steam generator 50, it is possible to further reduce the possibility of conduction between the pot GND electrode 81a and the pot detection electrode 81b due to the partition plate. Therefore, the possibility of erroneous detection of the pot water level detection unit 81 can be further reduced.

  The pot detection electrode 81b is disposed on the side farther from the water supply port 55a than the pot GND electrode 81a. For this reason, the contact by the vibration and surface tension with the water discharged from the water supply port 55a at the time of water supply and the detection electrode 81b for pots can be avoided. Thereby, it is possible to prevent the tank GND electrode 56a having the same potential as the pot GND electrode 81a and the pot detection electrode 81b from being electrically connected to each other, thereby preventing a shortage of water supply.

  Further, by separating the steam generating heater 52 and the water level detection chamber 51b by the isolation wall 51a, it is possible to make it difficult to transmit the foaming due to the boiling of water in contact with the steam generating heater 52 to the pot water level detecting unit 81. Accordingly, conduction between the pot GND electrode 81a and the pot detection electrode 81b due to foaming can be avoided, and the detection accuracy of the pot water level detection unit 81 can be improved.

  Note that the temperature of the water in the pot 51 may be increased by closely attaching a heater or the like to the outer peripheral surface of the pot 51. At this time, the peripheral wall of the pot 51 constitutes a heating means for heating the water in the pot 51, and the water level detection chamber 51 b is provided separately from the peripheral wall of the pot 51.

  In FIG. 8, a steam supply duct 34 connected to a circulation duct 35 described later is led out on the upper surface of the pot 51. An overflow pipe 98 connected to the tank water level detection container 91 is provided at the upper part of the peripheral surface of the pot 51. Thereby, the overflow water in the water supply channel 55 is guided to the water tank 71. The overflow level of the overflow pipe 98 is set higher than the normal water level in the pot 51 and lower than the steam supply duct 34.

  The bottom of the pot 51 is formed in a funnel shape, and a drain pipe 53 is led out from the lower end. A drain valve 54 is provided in the middle of the drain pipe 53. The drain pipe 53 has a gradient of a predetermined angle toward the water tank 71. Thereby, the drain valve 54 can be opened to drain the water in the pot 51 into the water tank 71, and the water tank 71 can be removed and discarded.

  A circulation duct 35 is provided on the outer wall of the heating chamber 20 from the back to the top. The circulation duct 35 opens an intake port 28 formed in the back wall of the heating chamber 20 and is connected to a steam temperature raising device 40 disposed above the heating chamber 20. The lower surface of the steam temperature raising device 40 is covered with the ejection cover 61, and the upper surface is covered with the upper cover 47.

  A blower fan 26 comprising a centrifugal fan is installed in the circulation duct 35, and the steam supply duct 34 is connected to the upstream side of the blower fan 26. The steam generated by the steam generator 50 by driving the blower fan 26 flows into the circulation duct 35 through the steam supply duct 34. Further, the steam in the heating chamber 20 is sucked from the intake port 28, and is jetted from the jet ports 65, 66 and 67 of the jet cover 61 through the circulation duct 35 and circulates.

  Therefore, the blower fan 26 and the jet ports 65, 66, 67 of the jet cover 61 constitute jetting means for jetting superheated steam into the heating chamber 20. Further, the blower fan 26 and the intake port 28 constitute suction means for sucking air and steam from the heating chamber 20. Since the blowing means and the suction means are configured by the common blower fan 26, the cost increase of the heating cooker 1 can be suppressed.

  In general, the gas in the heating chamber 20 is air, but when steam cooking is started, the air is replaced with steam. In the following description, it is assumed that the gas in the heating chamber 20 is replaced with steam.

  An exhaust duct 33 that branches via an electric damper 48 is provided at the upper part of the circulation duct 35. The exhaust duct 33 has an open end that faces the outside, and the steam in the heating chamber 20 is forcibly exhausted by opening the damper 48 and driving the blower fan 26. Further, an exhaust duct 32 communicating with the lower portion of the heating chamber 20 through an exhaust port 32a is led out. The exhaust duct 32 is made of a metal such as stainless steel, and has an open end facing the outside, and naturally exhausts the steam in the heating chamber 20. In addition, when mounting a magnetron in the heating cooker 1 and cooking by a microwave, outside air is inhaled through the exhaust duct 32.

  The steam temperature raising device 40 includes a steam heater 41 including a sheathed heater, and further heats the steam generated by the steam generator 50 to generate superheated steam. Therefore, the steam generator 50 and the steam temperature raising device 40 constitute a heating medium generating unit that generates a heating medium made of superheated steam. The steam temperature raising device 40 is disposed at the center of the ceiling of the heating chamber 20 as viewed in plan. Moreover, the area is narrower than the top surface of the heating chamber 20, and it is formed in a small volume so that high heating efficiency can be obtained.

  FIG. 12 is a block diagram showing a control configuration of the heating cooker 1. The heating cooker 1 includes a control device 80 having a microprocessor and a memory. The control device 80 includes a blower fan 26, a steam heater 41, a damper 48, a steam generation heater 52, a drain valve 54, a water supply pump 57, an operation panel 13, a pot water level detection unit 81, a tank water level detection unit 56, a temperature sensor 82, A humidity sensor 83 is connected. The cooking device 1 is driven by controlling each part according to a predetermined program by the control device 80.

  The operation panel 13 has a display unit (not shown) and displays the control status on the display unit. In addition, an operation command is input through various operation keys arranged on the operation panel 13. The operation panel 13 is also provided with a sound generator (not shown) that emits various sounds. The temperature sensor 82 detects the temperature in the heating chamber 20. The humidity sensor 83 detects the humidity in the heating chamber 20.

  In the heating cooker 1 having the above-described configuration, the door 11 is opened and the water tank 71 is pulled out from the water tank chamber 70, and water is put into the water tank 71. The filled water tank 71 is pushed into the water tank chamber 70 and connected to the tank water level detection container 91 by the joint portion 58. The object to be heated F is placed on the rack 22, the door 11 is closed, the operation panel 13 is operated, a menu is selected, and a start key (not shown) is pressed to start a cooking sequence. Thereby, the feed water pump 57 starts operation and water is supplied to the steam generator 50. At this time, the drain valve 54 is closed.

  When the water supply pump 57 is driven, water is supplied into the pot 51 through the water supply passage 55, and when the pot 51 reaches the reference water level L (see FIG. 9), the water supply is stopped by detection of the pot water level detection unit 81. At this time, the water level of the water tank 71 is monitored by the tank water level detection unit 56, and a warning is given if the water tank 71 does not have enough water for cooking. When a predetermined amount of water is put into the pot 51, the steam generating heater 52 is energized, and the steam generating heater 52 directly heats the water in the pot 51.

  The blower fan 26 and the steam heater 41 are energized at the same time as the energization of the steam generating heater 52 or at the time when the water in the pot 51 reaches a predetermined temperature. The steam in the heating chamber 20 is sucked into the circulation duct 35 from the intake port 28 by driving the blower fan 26. Further, when the water in the pot 51 boils, saturated steam at 100 ° C. and 1 atm is generated, and the saturated steam flows into the circulation duct 35 through the steam supply duct 34. At this time, the damper 48 is closed. The steam pumped from the blower fan 26 flows through the circulation duct 35 and flows into the steam temperature raising device 40.

  The steam that has flowed into the steam temperature raising device 40 is heated by the steam heater 41 to become superheated steam of 100 ° C. or higher. Usually, superheated steam whose temperature is increased from 150 ° C. to 300 ° C. is used. A part of the superheated steam is ejected from the fumarole 65 in the direction directly below (arrow A). Thereby, the upper surface of the to-be-heated material F contacts with superheated steam.

  Further, as shown in the front view of FIG. 13, a part of the superheated steam is ejected from the ejection port 66 in a diagonally downward direction (arrow B) on the side. The superheated steam ejected in the direction of arrow B is reflected by the reflecting portion 68 and guided below the object to be heated F. Thereby, the lower surface of the to-be-heated material F contacts with superheated steam.

  When the surface of the object to be heated F is 100 ° C. or less, the superheated steam is condensed on the surface of the object to be heated F. Since this condensation heat is as large as 539 cal / g, a large amount of heat can be given to the heated object F in addition to the convection heat transfer.

  In addition, a part of the superheated steam is ejected in a slanting downward direction (arrow C) from the air outlet 67 formed in the front surface portion 64 b of the ejection cover 61 toward the door 11. The steam in the heating chamber 20 is sucked from the intake port 28 by the blower fan 26. Due to this suction force, the air flow of superheated steam blown forward is bent and guided backward. Thereby, a part of superheated steam collides with the front part of the upper surface of the to-be-heated material F, and a part is guide | induced below the to-be-heated material F from the front. As a result, the superheated steam reaches the front portion of the heating chamber 20 to prevent insufficient heating of the front portion of the heated object F, and the heated object F can be cooked uniformly.

  Further, a part of the superheated steam jets obliquely downward in a direction between the direction toward the door 11 and the direction toward the side wall of the heating chamber 20 from the air outlet 67 formed in the corner portion 64c of the ejection cover 61. Is issued. Thereby, superheated steam spreads to the front corner of the heating chamber 20, prevents insufficient heating of the front portion of the heated object F, and allows the heated object F to be cooked more uniformly.

  Moreover, since the superheated steam in the heating chamber 20 is sucked from the intake port 28, the high-temperature superheated steam that directly hits the door 11 can be reduced. Therefore, it is not necessary to suppress the heating of the door 11 and use the door 11 having high heat resistance, and the cost increase of the heating cooker 1 can be prevented.

  When the suction force of the blower fan 26 is reduced, the airflow of superheated steam blown forward is bent at the lower part of the heating chamber 20. Thereby, more superheated steam can be guide | induced to the lower surface of the to-be-heated material F. FIG. When the suction force of the blower fan 26 is increased, the airflow of superheated steam blown forward is bent at the upper part of the heating chamber 20. Thereby, more superheated steam can be guide | induced to the upper surface of the to-be-heated material F. FIG.

  When the amount of steam in the heating chamber 20 increases with time, surplus steam is discharged to the outside through the exhaust duct 32.

  The superheated steam ejected from the air outlets 65, 66, 67 gives heat to the article F to be heated, and is then sucked into the circulation duct 35 from the air inlet 28 and flows into the steam temperature raising device 40. Thereby, the steam in the heating chamber 20 is repeatedly circulated for cooking.

  When cooking is completed, the control device 80 displays the end of cooking on the display unit of the operation panel 13 and notifies a signal sound. When the door 11 is opened by the user who is informed of the end of cooking, the damper 48 is opened, and the steam in the heating chamber 20 is rapidly forcedly exhausted from the exhaust duct 33. Thereby, the user can take out the to-be-heated material F from the inside of the heating chamber 20 safely, without touching high temperature steam.

  According to the present embodiment, the pot water level detection unit 81 includes the partition plate 81c that partitions the pot GND electrode 81a and the pot detection electrode 81b suspended from the ceiling, and thus the pot water level detection unit 81 is generated at the ceiling of the pot water level detection unit 81. It is possible to prevent conduction between the pot GND electrode 81a and the pot detection electrode 81b due to condensation. As a result, the possibility of erroneous detection of the pot water level detection unit 81 is reduced to improve detection accuracy, and water supply is performed more reliably when the water level of the pot 81 is lower than the water level L. Therefore, cooking failure due to water shortage during cooking can be prevented.

  Further, the lower end of the partition plate 81c is disposed above the lower end of the pot GND electrode 81a and the lower end of the pot detection electrode 81b. Therefore, when the water level is lower than the lower end of the pot GND electrode 81a and the lower end of the pot detection electrode 81b, between the pot GND electrode 81a and the partition plate 81c due to surface tension, and between the pot detection electrode 81b and the partition plate 81c. Can be reduced. Therefore, the possibility of erroneous detection of the pot water level detection unit 81 can be reduced and detection accuracy can be further improved.

  The steam generator 50 has the pot water level detection unit 81 disposed in the pot 51, but the pot water level detection unit 81 may be disposed in a detection container communicating with the pot 51. Also in this case, the same effect can be obtained by the same configuration as described above.

  INDUSTRIAL APPLICABILITY The present invention can be used for household and commercial cooking devices that cook with steam.

The front view which shows the heating cooker of embodiment of this invention The side view which shows the heating cooker of embodiment of this invention The front view which shows the state which opened the door of the heating cooker of embodiment of this invention The front view which shows the heating chamber of the heating cooker of embodiment of this invention The perspective view which shows the ejection cover of the heating cooker of embodiment of this invention The top view which shows the ejection cover of the heating cooker of embodiment of this invention Side surface sectional drawing which shows the ejection cover of the heating cooker of embodiment of this invention The figure which shows the internal structure of the heating cooker of embodiment of this invention Front sectional drawing which shows the steam generator of the heating cooker of embodiment of this invention Top surface sectional drawing which shows the principal part of the water level detection part of the heating cooker of embodiment of this invention Top surface sectional drawing which shows the principal part of the water level detection part of the heating cooker of embodiment of this invention The block diagram which shows the structure of the heating cooker of embodiment of this invention. The front view which shows the heating cooker of embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heating cooker 11 Door 20 Heating chamber 21 Receptacle 26 Blower fan 28 Inlet 31 Exhaust fan 32, 33 Exhaust duct 34 Steam supply duct 35 Circulation duct 40 Steam temperature rising device 41 Steam heater 47 Outer cover 48 Damper 50 Steam generator 51 Pot 51a Isolation wall 51b Water level detection chamber 51c Boss part 52 Steam generating heater 54 Drain valve 55 Water supply path 55a Water supply port 56 Tank water level detection part 57 Water supply pump 61 Spout cover 63 Plane part 64 Inclined surface 64a Side part 64b Front part 64c Corner Portions 65, 66, 67 Air outlets 65a, 66a, 67a Guide portion 68 Reflection portion 71 Water tank 81 Pot water level detection portion 81a Pot GND electrode 81b Pot detection electrode 81c Partition wall 91 Tank water level detection container F Heated object

Claims (7)

An evaporation container that stores water supplied from the water supply means, a heating means that heats the water in the evaporation container, and a water level detection unit that detects the water level of the evaporation container, using steam generated in the evaporation container In a heating cooker that cooks an object to be heated,
The water level detection unit includes a GND electrode that is maintained at a reference potential, a detection electrode that is electrically connected to the GND electrode through water supplied to the evaporation container, and a partition that partitions the GND electrode and the detection electrode. A heating cooker, wherein the GND electrode, the detection electrode, and the partition plate are suspended from the ceiling of the water level detection unit.   The cooking device according to claim 1, wherein the lower end of the partition plate is disposed above the lower end of the GND electrode and the lower end of the detection electrode.   The cooking device according to claim 1, wherein the lower end of the partition plate is disposed 20 mm or more above the lower end of the GND electrode and the upper end of the detection electrode.   The heating according to any one of claims 1 to 3, wherein the GND electrode and the detection electrode are formed in a thin plate shape, and the surfaces forming the thicknesses of the GND electrode and the detection electrode are opposed to each other. Cooking device.   The cooking device according to any one of claims 1 to 4, wherein the partition plate is tapered.   The cooking device according to any one of claims 1 to 5, wherein the water level detection unit is arranged in the evaporation container.   The heating means includes a spiral heater disposed in the evaporation container, and a cylindrical isolation wall extending from the ceiling of the evaporation container into the spiral heater is provided, and the water level is provided in the isolation wall. The cooking device according to any one of claims 1 to 6, wherein a detector is arranged.

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