JP5809441B2 - Steam generator - Google Patents

Description

  The present invention relates to a steam generator used in a steam convection oven or the like.

  The following Patent Document 1 discloses a steam convection oven that heats and cooks food with hot air containing steam, and this steam convection oven includes a heater and a blower fan in a cooking chamber provided in the housing. An induction heating type steam generator for supplying steam to the side of the cooking chamber in the housing is provided. When cooking food with hot air containing steam in this steam convection oven, steam is supplied from the steam generator into the cooking chamber, and the fan containing the steam in the cooking chamber is heated by the heater. Convection.

  The steam generator used in this steam convection oven has a steam generating container for storing a predetermined amount of water to generate steam, an induction heating coil wound around the outer periphery of the steam generating container, and an upper part in the steam generating container. It comprises a supported resin holder and a heating body composed of a plurality of heating rods whose upper ends are fixed to the holder and suspended in a steam generating container. In the heating rod, a portion that generates heat by the induction heating coil is a heating portion, a portion that does not generate heat continuously above the heating portion is a non-heating portion, and the upper end of the non-heating portion is fixed to the holder. In this steam generator, when a high frequency current is supplied to the induction heating coil, the heat generating part of the heating rod generates heat to heat the water in the steam generating container, and the water in the steam generating container is discharged as steam. . At this time, since the water level in the steam generation container decreases due to the generation of steam, when the upper limit water level exceeding the heat generating part of the heating rod is detected, the water supply by the water supply means is stopped and is slightly below the upper end of the heat generating part. When the lower limit water level is detected, the water is supplied by the water supply means.

JP 2010-255871 A

  When steam is generated in the steam generation vessel, the heating part of the heating rod does not exchange heat with the water in the steam generation container and does not overheat, but if many bubbles adhere to the surface of the heating part of the heating rod, In some cases, the heat generating part of the heating rod is not easily exchanged with the water in the steam generating container, resulting in an overheated state. Furthermore, depending on the state of the heating rod, the heat generating part of the heating rod is covered with a vapor film, and film boiling starts directly from the contact surface between the vapor film and the liquid, and the heat generating part of the heating rod directly exchanges heat with water. In some cases, it was overheated.

  In addition, when steam is generated in the steam generating container, the water level in the steam generating container is controlled to be the upper limit water level exceeding the heat generating part of the heating rod, so that the heat of the heat generating part of the heating rod is large. Part is heat exchanged with water, but part is transferred to the non-heat generating part. The non-heat generating part of the heating rod is heat exchanged by the hot water that bounces when boiling, and it is difficult to become overheated, but this hot water is not uniformly applied to each heating rod, so the non-heating part of some heating rods Sometimes overheated. As described above, when the heating rod is overheated, the holder for fixing the heating rod is melted, and the heating rod may drop into the steam generation container, or the steam generation container for supporting the holder may be melted. The present invention aims to solve such problems.

In order to solve the above problems, the present invention provides a steam generation container for storing a predetermined amount of water to generate steam, a water level sensor for detecting the water level in the steam generation container, and supplying water to the steam generation container Water supply means, an induction heating coil wound around the outer periphery of the steam generating container, a holder supported on the upper part of the steam generating container, and an upper end portion fixed to the holder and suspended in the steam generating container. The heating rod is a heating element, and the heating rod is a heating part when the high frequency current is supplied to the induction heating coil, and the non-heating part is a part that does not generate heat above this heating part. the upper end portion of the non-heat generating portion to so that is fixed to the holder, and controls the operation of the water supply means so that the water level of the position of the upper end portion of the heat generating portion of the water level in the steam generator vessel based on the detected water level of the water level sensor In the steam generator, There is provided a steam generator, characterized in that the non-heat generating portion of the rod to form pores as water retention means.

In the steam generator configured as described above, since the pores are formed as the moisture retaining means in the non-heating portion of the heating rod , the hot water that jumps when boiling in the steam generating container is formed in the non-heating portion. It flows into the hole by capillary action, and the non-heat generating portion of the heating rod is exchanged with the hot water flowing into the pore, so that the heating rod is not easily overheated.

It is a front view of 1st Embodiment of the steam convection oven which incorporated the steam generator of this invention. It is a longitudinal cross-sectional view in the AA line of FIG. It is a longitudinal cross-sectional view in the BB line of FIG. It is a partially broken longitudinal cross-sectional view of a steam generator. It is a block diagram of the control apparatus of a steam convection oven. It is a partially broken longitudinal cross-sectional view of the steam generator of 2nd Embodiment. It is a partially broken longitudinal cross-sectional view of the steam generator of 3rd Embodiment. It is a perspective view of the heating body of 3rd Embodiment. It is a top view of the state which removed the steam extraction pipe | tube of the steam generator of 4th Embodiment. It is a perspective view of the steam generation container and heating body of 4th Embodiment. It is a perspective view of the steam generator of 5th Embodiment (The description of the water level detection container was abbreviate | omitted). It is a partially broken longitudinal cross-sectional view of the steam generator of 5th Embodiment.

  Hereinafter, a first embodiment in which a steam generator according to the present invention is applied to a steam convection oven will be described with reference to the accompanying drawings. As shown in FIGS. 1 to 3, the steam convection oven 10 includes a food cooking chamber 12 disposed in a housing 11 and a heater 13 provided in the cooking chamber 12 for heating the cooking chamber 12. A fan 14 provided in the cooking chamber 12 for convection of the air in the cooking chamber 12, a temperature sensor 15 for detecting the temperature in the cooking chamber 12, and the cooking chamber 12 inside the housing 11. The steam generator 20 is provided in a machine room 16 formed on the side of the container 11 and supplies steam into the cooking chamber 12. An operation panel 17 is provided on the front panel of the housing 11.

  As shown in FIG. 4, the steam generator 20 of the present invention includes a steam generation container 21 that stores a predetermined amount of water to generate steam, an induction heating coil 27 wound around the outer periphery of the steam generation container 21, And a heating element 30 that is housed in the steam generation vessel 21 and generates heat by supplying a high-frequency current to the induction heating coil 27.

  The steam generating container 21 is made of a resin cylindrical member that is open at the top and bottom. The steam generating container 21 is installed on the floor surface of the machine room 16 and is connected to a drain tank 18 used for discharging water in the cooking chamber 12 via a connecting cylinder 22. It is erected. The upper end opening of the steam generating container 21 is a steam discharge port 21a, and a steam outlet tube 23 for leading the discharged steam into the cooking chamber 12 is connected to the discharge port 21a. Further, the lower end opening of the steam generating container 21 is a drain outlet 21b, and a drain valve 24 is provided in the connecting tube 22 connected to the drain outlet 21b. When the drain valve 24 is opened, the steam generating container 21 is opened. The water inside is discharged to the drain tank 18. A tapered surface 21 c is formed on the upper part of the steam generating container 21 so as to be narrowed downward to support the heating body 30. A temperature sensor attachment cylinder portion 21d for attaching the temperature sensor 33 to the lower side of the tapered surface 21c is formed in the upper portion of the steam generation container 21.

  Annular brackets 25 and 26 are provided on the outer periphery of the intermediate portion in the vertical direction of the steam generating container 21 so as to be separated from each other in the vertical direction, and an induction heating coil 27 is wound between the brackets 25 and 26. The brackets 25 and 26 are provided with a plurality of rod-shaped ferrites 28 to prevent electromagnetic waves leaking from the induction heating coil 27 along the circumferential direction thereof.

  As shown in FIG. 4, a heating body 30 is accommodated in the steam generation container 21 and generates heat by supplying high-frequency current to the induction heating coil 27 to heat the water in the steam generation container 21. The heating body 30 includes a holder 31 supported on the upper part of the steam generation container 21, and seven heating rods 32 having an upper end fixed to the holder 31 and suspended in the steam generation container 21. Yes. The holder 31 is a substantially annular metal plate having a steam passage formed in the center, and has six projecting portions 31a formed at equal intervals on the outer peripheral portion and a tapered surface 21c formed on the upper portion of the steam generating vessel 21. It is supported by being locked.

  The upper ends of the seven heating rods 32 are fixed to the holder 31 at equal intervals along the circumferential direction. The seven heating rods 32 are conductive metal rod-shaped members made of a magnetic material member, and extend in the axial direction of the steam generation vessel 21 and are arranged at equal intervals on a concentric circle centered on the central axis. Each heating rod 32 is the same height as the induction heating coil 27, and a portion that generates heat when a high-frequency current is supplied thereto is defined as a heat generating portion 32a, and a portion that does not generate heat at an upper portion and a lower portion from the heat generating portion 32a. Are the non-heat generating portions 32b and 32c. Each heating rod 32 has an upper non-heating portion 32 b fixed to the holder 31. The non-heating part 32b on the upper part of each heating rod 32 is formed with a pore 32d composed of a plurality of through holes. Further, one of the seven heating rods is provided with a temperature detection hole 32e for detecting the temperature of the non-heat generating portion 32b in the upper part, and this temperature detection hole 32e is formed in the steam generating container 21. It is at the same height as the temperature sensor mounting cylinder portion 21d.

  A temperature sensor 33 is attached to the temperature sensor attachment cylinder portion 21d above the steam generation container 21. The temperature sensor 33 is for detecting the overheated state of the heating body 30 by detecting the temperature of the non-heat generating portion 32 b of the heating rod 32. The temperature sensor 33 a of the temperature sensor 33 is inserted so as to be in surface contact with the temperature detection hole 32 e of the heating rod 32.

  A substantially cylindrical water level detection container 40 for detecting the water level in the steam generation container 21 is erected on the side of the steam generation container 21, and the water level detection container 40 communicates with a lower part of the steam generation container 21. 41 is connected in communication. A water level sensor 42 for detecting the water level in the steam generation container 21 is provided in the water level detection container 40. The water level sensor 42 is composed of a float switch, and a water level that exceeds the heat generating part 32a of the heating rod 32 in the steam generating container 21 by a float supported by a support member so as to move up and down is slightly below the upper limit water level L1 and the heat generating part 32a. The lower limit water level L2 is detected as the water level on the side. A water supply means 44 is connected to a water supply section 43 provided at the upper part of the water level detection container 40. The water supply means 44 includes a water supply pipe 45 led out from a water supply source such as a water supply, and a water supply valve 46 interposed in the water supply pipe 45. If the water supply valve 46 is opened, water is supplied into the water level detection container 40, and the water supplied into the water level detection container 40 is sent into the steam generation container 21 through the communication pipe 41. Further, the water level detection container 40 is provided with an overflow pipe 47 for draining water of a water level slightly exceeding the upper limit water level L1.

  The steam convection oven 10 includes a control device 50, and as shown in FIG. 5, the control device 50 includes a heater 13, a blower fan 14, an internal temperature sensor 15, an operation panel 17, and a steam generator 20. Each device is connected to a drain valve 24, an induction heating coil 27, a temperature sensor 33, a water level sensor 42, and a water supply valve 46. The control device 50 includes a microcomputer (not shown), and the microcomputer includes a CPU, a RAM, a ROM, and a timer (all not shown) connected via a bus. The CPU is based on the input from the operation panel 17, the internal temperature sensor 15, the temperature sensor 33 of the steam generator 20, and the detection of the water level sensor 42, the heater 13, the blower fan 14, the drain valve 24, the induction heating coil 27, and the like. A program for controlling the operation of the water supply valve 46 is executed.

  In the steam convection oven 10, for example, when executing a cooking program in the combination mode, the control device 50 includes the heater 13, the steam generator 20, and the blower fan 14 so that the temperature and the amount of steam are suitable for cooking. The operation is controlled. When the steam generation apparatus 20 is operated by executing a combination mode cooking program in the steam convection oven 10, a high-frequency current is supplied to the induction heating coil 27, and the heat generating portion 32 a of the heating rod 32 generates heat. The water in the steam generating container 21 is heated by the heating rod 32 that generates heat to become hot water, and then becomes steam. This steam is sent from the steam outlet tube 23 into the cooking chamber 12. Since the water level in the steam generation container 21 decreases due to the generation of steam, the control device 50 controls the water level in the steam generation container 21 to be a water level between the upper limit water level L1 and the lower limit water level L2. Specifically, when the water level sensor 42 detects the lower limit water level L2, the control device 50 opens the water supply valve 46 to supply water, and when the water level sensor 42 detects the upper limit water level L1, the control device 50 closes the water supply valve 46. Controls to stop water supply. Further, when the steam generator 20 is operated in this way, the control device 50 controls the supply of the high-frequency current to the induction heating coil 27 when the heating body 30 is overheated. Specifically, when the control device 50 detects 110 ° C. or more defined as an overheated state by the temperature sensor 33, the control device 50 stops supplying high-frequency current to the induction heating coil 27.

  In the steam generator 20 configured as described above, when a high-frequency current is supplied to the induction heating coil 27 to cause the heat generating portion 32a of the heating rod 32 to generate heat, most of the heat generating portion 32a of the heating rod 32 is heated. The heat is exchanged with the hot water in the steam generation container 21, but a part of the heat is transmitted to the non-heating part 32 b. The non-heat generating portion 32b of the heating rod 32 is not easily overheated by heat exchange by hot water that jumps when boiling, but this hot water is not uniformly applied to each heating rod 32. There is a possibility that the non-heat generating portion 32b of the non-heat generating portion is overheated. Since the non-heat generating portion 32b in the upper portion of the heating rod 32 of this embodiment has a plurality of pores 32d as moisture retaining means, the hot water that jumps when boiling is brought into the pores 32d by capillary action. Will flow in and stay. As a result, the non-heat generating portion 32b of the heating rod 32 exchanges heat with the hot water held in the pores 32d without being temporarily exposed to the hot water that jumps up in the steam generating container 21, so that the overheated state is achieved. It becomes difficult to become. Further, since the heat conductivity of the non-heat generating portion 32b is reduced by the large number of pores 32d, the heat transmitted from the heat generating portion 32a is not easily transmitted to the non-heat generating portion 32b. Thus, since the non-heating part 32b of the heating rod 32 is less likely to be overheated, the situation in which the induction heating coil 27 temporarily stops supplying high-frequency current is reduced, and steam can be generated efficiently. . Further, since the non-heat generating portion 32 b of the heating rod 32 is less likely to be overheated, the heating rod 32 melts the holder 31 to which the heating rod 32 is fixed and falls into the steam generation container 21, or the steam generation container 21 through the holder 31. The risk of melting is reduced.

  In the present embodiment, a plurality of pores 32d are formed in the non-heat generating portion 32b of the heating rod 32 as moisture holding means, but the present invention is not limited to this, and other moisture holding means is described below. The following means can be adopted. As another moisture holding means, the non-heat generating portion 32b of the heating rod 32 may hold hot water that jumps up by boiling with its surface as a rough surface. When this is done, the non-heat generating portion 32b of the heating rod 32 can be used as hot water held on the surface of the non-heat generating portion 32b made of a rough surface, even if the hot water splashing in the steam generating container 21 is not temporarily applied. Heat exchange is performed and it becomes difficult to be in an overheated state. Further, by making the non-heat generating portion 32b of the heating rod 32 rough, it is possible to omit the surface finishing process in which the surface of the non-heat generating portion 32b of the heating rod 32 is a smooth surface, thereby reducing the cost. Further, as another moisture holding means, a scale made of calcium or the like or a water absorbing material such as ceramics or the like is attached to the surface of the non-heat generating portion 32b of the heating rod 32 is the same as described above. The effect of can be obtained. Further, as another moisture holding means, a hydrophilic coating may be applied to the surface of the non-heat generating portion 32b of the heating rod 32, and the same effect as described above can be obtained even in this case.

  Next, a second embodiment of the steam generator according to the present invention will be described. In this steam generator 20A, the heating body 30 of the first embodiment described above is replaced with a heating body 30A. The heating body 30A will be described below. As shown in FIG. 6, the heating body 30 </ b> A includes a holder 31 supported in contact with the upper tapered surface 21 c of the steam generation container 21, and an upper end fixed to the holder 31 and suspended in the steam generation container 21. 7 heating rods 32A provided. The upper ends of the seven heating rods 32A are fixed to the holder 31 at equal intervals along the circumferential direction. The seven heating rods 32A are conductive metal rod-like members made of a magnetic material member, and extend in the axial direction of the steam generation vessel 21 and are arranged at equal intervals on a concentric circle centered on the central axis. Each heating rod 32A is the same height as the induction heating coil 27, and a portion that generates heat when a high-frequency current is supplied thereto is defined as a heat generating portion 32Aa, and a portion that does not generate heat at an upper portion and a lower portion from the heat generating portion 32Aa. Are the non-heat generating portions 32Ab and 32Ac. Each heating rod 32 </ b> A has a non-heat generating portion 32 </ b> Ab in the upper part fixed to the holder 31. A plurality of longitudinal grooves 32Ad extending in the axial direction are formed in the heat generating portion 32Aa and the lower non-heat generating portion 32Ac of each heating rod 32A in the circumferential direction. This vertical groove 32Ad makes it easy to separate bubbles adhering to the surface of the heating rod 32A when the heating rod 32A generates heat to heat the water in the steam generating container 21. Other than these, the second embodiment is the same as the first embodiment.

  In the steam generator 20A configured as described above, when high-frequency current is supplied to the induction heating coil 27 to cause the heat generating portion 32Aa of the heating rod 32A to generate heat, the water in the steam generating container 21 is heated to the heat generating portion of the heating rod 32A. After being heated by the heat generated from 32Aa to become hot water, it becomes steam. At this time, air bubbles adhered to the surface of the heat generating portion 32Aa of the heating rod 32A, and the heat generating portion 32Aa was not easily exchanged with hot water by the air bubbles, and might be overheated. Further, when the surface of the heat generating portion 32Aa of the heating rod 32A is covered with a vapor film, film boiling starts to start boiling directly from the contact surface between the vapor film and the liquid, and the heat generating portion 32Aa of the heating rod 32A directly heats with hot water. There was a risk of overheating without replacement. In the heating portion 32Aa of the heating rod 32A of this embodiment, a plurality of longitudinal grooves 32Ad extending in the axial direction are formed in the circumferential direction as bubble adhesion preventing means of the moisture holding means. Air bubbles attached to the surface easily move to the water surface along the vertical grooves 32Ad. As a result, the heat generating portion 32Aa is less likely to be hindered from heat exchange with water by the bubbles, and the heating rod 32A is less likely to be in an overheated state caused by being less likely to exchange heat with water. In addition, since a plurality of longitudinal grooves 32Ad extending in the axial direction are formed in the heat generating portion 32Aa of the heating rod 32A in the circumferential direction, even if scales adhere to the longitudinal grooves 32Ad, the adhered scales are cracked based on this. Since it becomes easy to fall, heat_generation | fever part 32Aa can suppress the fall of the heat exchange with the hot water which arises by adhesion of a scale.

  In the present embodiment, a plurality of longitudinal grooves 32Ad extending in the axial direction are formed in the heat generating portion 32Aa of the heating rod 32A as the bubble adhering prevention means of the moisture holding means in the circumferential direction, but the present invention is not limited to this. However, the following means can be employed as other means for preventing bubble adhesion. As another bubble adhesion preventing means, the heat generating portion 32Aa of the heating rod 32A may have a rough surface to suppress bubble adhesion. In such a case, the above-described operational effects can be obtained, and surface finishing processing in which the surface of the heat generating portion 32Aa of the heating rod 32A is a smooth surface can be omitted, and the cost can be reduced. Further, as another moisture holding means, a hydrophilic coating may be applied to the surface of the heat generating portion 32Aa of the heating rod 32A, and the same effect as described above can be obtained even in this case.

  Next, a third embodiment of the steam generator according to the present invention will be described. In this steam generator 20B, the heating body 30 of the first embodiment described above is replaced with the heating body 30B, and the heating body 30B will be described below. As shown in FIGS. 7 and 8, the heating body 30 </ b> B includes a holder 31 </ b> B supported in contact with the upper tapered surface 21 c of the steam generation container 21, and an upper end portion fixed to the holder 31 </ b> B and the steam generation container 21. And seven heating rods 32 suspended in the interior. The holder 31B is made of a substantially annular resin member having a steam passage formed in the center, and seven protrusions 31Ba formed at equal intervals on the outer peripheral portion are formed on a tapered surface 21c formed on the upper portion of the steam generating container 21. It is supported by being locked. In the holder 31B, the upper ends of the seven heating rods 32 are integrally fixed by insert molding.

  The seven heating rods 32 extend in the axial direction of the steam generating vessel 21 and are arranged at equal intervals on a concentric circle centered on the central axis. Each heating rod 32 is located at the same height as the induction heating coil 27 and generates heat when a high-frequency current is supplied to the heating rod 32 as a heating part 32a. The heating bar 32 is connected to the induction heating coil 27 above and below the heating part 32a. The portions that do not generate heat even when a high-frequency current is supplied are defined as non-heat generating portions 32b and 32c. Further, one of the seven heating rods 32 is provided with a temperature detection hole 32e for detecting the temperature of the non-heat generating portion 32b in the upper part, and this temperature detection hole 32e is formed in the steam generating container 21. It is at the same height as the temperature sensor mounting cylinder portion 21d.

  An annular temperature sensor erroneous insertion prevention plate 34B is fixed to the outer periphery of the seven heating rods 32 at the lower end of the holder 31B. The temperature sensor erroneous insertion preventing plate 34B inserts the temperature sensor 33 into the temperature sensor mounting cylinder portion 21d when the temperature detection hole 32e of the heating rod 32 is not in a position facing the temperature sensor mounting cylinder portion 21d of the steam generating container 21. So that it cannot be attached. A temperature sensor insertion hole 34Ba through which the temperature sensing portion 33a of the temperature sensor 33 can be inserted is formed in the temperature sensor erroneous insertion prevention plate 34B at a position facing the temperature detection hole 32e of the heating rod 32. 7 and 8 omit the description of the pores 32d, but other than these are the same as in the first embodiment described above.

  In the steam generator 20B configured as described above, when the heating body 30B is accommodated in the steam generation container 21, the temperature detection hole 32e of the heating rod 32 faces the temperature sensor mounting cylinder portion 21d of the steam generation container 21. Otherwise, the temperature sensing part 33a of the temperature sensor 33 could not be inserted into the temperature detection hole 32e. If the temperature sensing part 33a of the temperature sensor 33 is not inserted into the temperature detection hole 32e, the temperature sensor 33 cannot detect the temperature of the non-heating part 32b of the heating rod 32. In the steam generator 20B of this embodiment, the heating element 30B is provided with a temperature sensor erroneous insertion prevention plate 34B. When the temperature detection hole 32e of the heating rod 32 is at a position facing the temperature sensor mounting cylinder portion 21d of the steam generating container 21, a temperature sensor erroneous insertion preventing plate 34B is provided between the temperature detection hole 32e and the temperature sensor mounting cylinder portion 21d. Since the temperature sensor insertion hole 34Ba is arranged, the temperature sensing portion 33a of the temperature sensor 33 is inserted into the temperature detection hole 32e through the temperature sensor insertion hole 34Ba. On the other hand, when the temperature detection hole 32e of the heating rod 32 is not at a position facing the temperature sensor mounting cylinder portion 21d of the steam generation container 21, the temperature sensor 33 hits the outer peripheral surface of the temperature sensor erroneous insertion preventing plate 34B and cannot be inserted. Thereby, it can prevent attaching the temperature sensing part 33a of the temperature sensor 33 in the state which is not penetrated by the temperature detection hole 32e. Further, since the temperature sensor erroneous insertion preventing plate 34B is in contact with the inner peripheral surface of the steam generation container 21B without a gap, the heating body 30B is not easily tilted in the steam generation container 21.

  Next, a fourth embodiment of the steam generator according to the present invention will be described. In this steam generation apparatus 20C, the steam generation container 21 and the heating body 30B of the third embodiment described above are replaced with the steam generation container 21C and the heating body 30C, which will be described below. As shown in FIGS. 9 and 10, on the inner peripheral surface of the upper end portion of the steam generation vessel 21C, there are seven temperature detection holes 32e for positioning the heating rod 32 at positions facing the temperature sensor mounting cylinder portion 21d. A concave groove 21Ce is formed. These concave grooves 21Ce are for fitting the seven protrusions 31Ca of the holder 31C of the heating body 30C. Of the seven concave grooves 21Ce, the concave groove 21Ce1 arranged immediately above the temperature sensor mounting cylinder 21d is the other groove 21Ce. The width is wider than the concave groove 21Ce.

  Of the protrusions 31Ca formed on the outer periphery of the holder 31C of the heating body 30C, the protrusion 31Ca1 disposed immediately above the heating rod 32 in which the temperature detection hole 32e is formed is the inner end of the upper end of the steam generating container 21. It is formed wider than the other protrusions 31Ca so as to be able to fit into the recessed groove 21Ce1 formed wider on the peripheral surface. In addition, the other protrusion 31Ca has a width that can be fitted to the groove 21Ce other than the groove 21Ce1 formed to be wide. Note that the steam generator 20C of this embodiment is the one in which the temperature sensor erroneous insertion prevention plate of the third embodiment is eliminated, and the description of the pores 32d is omitted in FIG. This is the same as the third embodiment.

  In the steam generator 20C configured as described above, when the heating body 30C is accommodated in the steam generation container 21C, the temperature detection hole 32e of the heating rod 32 faces the temperature sensor mounting cylinder portion 21d of the steam generation container 21C. Otherwise, the temperature sensing part 33a of the temperature sensor 33 could not be inserted into the temperature detection hole 32e. If the temperature sensing part 33a of the temperature sensor 33 is not inserted into the temperature detection hole 32e, the temperature sensor 33 cannot detect the temperature of the non-heating part 32b of the heating rod 32. In this steam generator 20C, of the seven concave grooves 21Ce formed on the inner peripheral surface of the upper end portion of the steam generation container 21C, the concave groove 21Ce1 disposed immediately above the temperature sensor mounting cylinder portion 21d is another concave groove 21Ce. It is formed wider than the groove 21Ce. Of the seven protrusions 31Ca formed on the outer periphery of the holder 31C of the heating body 30C, the protrusion 31Ca1 disposed immediately above the heating rod 32 in which the temperature detection hole 32e is formed is more than the other protrusions 31Ca. Widely formed. As a result, the heating element 30C cannot be accommodated in the steam generation container 21C unless the wide protrusion 31Ca1 of the holder 31C is positioned opposite the wide concave groove 21Ce1 of the steam generation container 21C. The temperature detection hole 32e is always at a position facing the temperature sensor mounting cylinder portion 21d of the steam generation container 21C. Thereby, it can prevent attaching the temperature sensing part 33a of the temperature sensor 33 in the state which is not penetrated by the temperature detection hole 32e.

  Next, a fifth embodiment of the steam generator according to the present invention will be described. In this steam generation apparatus 20D, the steam generation container 21 and the heating body 30B of the third embodiment described above are replaced with the steam generation container 21D and the heating body 30D, which will be described below. As shown in FIGS. 11 and 12, seven temperature sensor mounting cylinders 21 </ b> Dd for mounting seven temperature sensors 33 </ b> D are formed at equal intervals in the circumferential direction on the upper part of the steam generation container 21 </ b> D. In addition, temperature detection holes 32De are formed in the upper portions of all seven heating rods 32D of the heating body 30D. The seven temperature sensors 33D are attached to the temperature sensor attachment cylinders 21Dd of the steam generation container 21D, and the temperature sensing parts 33Da of the temperature sensors 33D are inserted into the temperature detection holes 32De of the heating rods 32D. Note that the steam generator 20D of this embodiment is an abolishment of the temperature sensor erroneous insertion prevention plate of the third embodiment, and the description of the pores 32d is omitted in FIG. This is the same as the third embodiment.

  In the steam generator 20D configured as described above, the temperature detection holes 32De are formed in all of the seven heating rods 32D, and the seven temperature sensors 33D are inserted into the temperature detection holes 32De. The detected temperatures of the seven temperature sensors 33D are input to the control device 50, and when any one of these temperature sensors 33D detects 110 ° C. defined as the overheating temperature, the control device 50 causes the induction heating coil 27 to generate a high-frequency current. Stop supplying. Thereby, even if some of the seven heating rods 32D are overheated, heating by the heating body 30D can be stopped.

  The present invention is not limited to the steam generators of the above-described embodiments, and the steam generators of the above-described embodiments may be appropriately combined to prevent the heating body from being overheated. .

 DESCRIPTION OF SYMBOLS 20 ... Steam generator, 21 ... Steam generation container, 27 ... Induction heating coil, 30 ... Heating body, 31 ... Holder, 32 ... Heating rod, 32a ... Heat generating part, 32b ... Non-heat generating part, 33d ... Fine pore, 33Ad ... groove.

Claims (1)

A steam generation container for storing a predetermined amount of water and generating steam;
A water level sensor for detecting the water level in the steam generating container;
Water supply means for supplying water into the steam generating container;
An induction heating coil wound around the outer periphery of the steam generating container;
A holder supported on the upper part in the steam generation container, and a heating body composed of a heating rod having an upper end fixed to the holder and suspended in the steam generation container,
In the heating rod, a portion that generates heat when a high-frequency current is supplied to the induction heating coil is a heating portion, a portion that does not generate heat above the heating portion is a non-heating portion, and the upper end of the non-heating portion is the holder. to so that was fixed,
In the steam generator in which the operation of the water supply means is controlled so that the water level in the steam generation container becomes the water level at the upper end portion of the heat generating unit based on the detected water level of the water level sensor .
A steam generator characterized in that pores are formed in the non-heating portion of the heating rod as moisture retaining means .

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