JP6546406B2 - Steam generator - Google Patents

Description

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

  Patent Document 1 below discloses a heating cooker for cooking food with hot air containing steam. The heating cooker includes a cooking chamber for storing food, a heater for heating the inside of the cooking chamber, a fan for circulating air in the cooking chamber, and a steam generator for supplying steam into the cooking chamber. The foodstuff accommodated in the cooking chamber is cooked by circulating air heated by the heater together with the steam supplied from the steam generator by the fan.

  The steam generating device of the heating cooker includes a steam generating container storing water of a predetermined water level, heating means for heating water in the steam generating container, a water level detection tank connected to the lower part of the steam generating container, A water level sensor is provided in the detection tank and detects the water level in the steam generating container by detecting the water level inside, and a water supply unit in which a water supply pipe is connected to the top of the water level detection tank. In this steam generator, the water supplied from the water supply unit into the water level detection tank flows from the water level detection tank into the steam generation container, and the water flowing into the steam generation container is heated by the heating means to become steam. Are sent to the cooking cabinet. The water in the steam generation container gradually decreases due to the generation of steam, but the water in the water level detection tank flows into the steam generation container so that the water level is the same as the water level of the water level detection tank. The water in the water level detection tank gradually decreases to flow into the steam generation container, but the water level detection tank is supplied with water from the water supply unit so as to reach a predetermined water level based on detection by the water level sensor.

  Moreover, the overflow part (overflow pipe) which discharges the water of an excessive water level is provided in the water level detection tank. A drainage pipe is connected to the discharge port of the overflow portion of the water level detection tank, and the tip of the drainage pipe is connected to the drainage tank for discharging the water of the cooking chamber. The excess water level supplied into the water level detection tank is drained to the drainage tank through the drain pipe for the amount of water exceeding the upper edge of the overflow portion. Also, high temperature air containing steam from the cooking chamber flows into the drainage tank during cooking, and high temperature air containing steam flowing into the drainage tank rises into the drainage pipe and flows into the water level detection tank Sometimes. For this reason, in order to prevent the steam flowing into the water level detection tank from leaking into the machine room, the upper surface opening of the water level detection tank is covered in a substantially sealed state by the lid.

JP, 2013-200111, A

  In the heating cooker of Patent Document 1 described above, it may be preferable to miniaturize not only the steam generation container but also the water level detection tank as much as possible due to the size of the machine room in which the steam generation device is installed. When the water level detection tank is downsized, the water level sensor and the water supply unit will be close to each other in the water level detection tank, so the water surface around the water level sensor in the water level detection tank will be waved by the water injected from the water supply unit. And the water level sensor could not detect the correct water level in the water level detection tank.

  In order to cope with this, the cylinder part surrounding the water level sensor is extended downward on the lower surface of the lid constituting the upper wall of the water level detection tank so that the water supply part and the overflow part are on the outside, It has been studied to prevent the surface of the water waved by the water injected from the water supply portion outside the cylindrical portion in the water level detection tank from being transmitted to the water surface around the water level sensor inside the cylindrical portion by the cylindrical portion. Although the water surface around the water level sensor will not be ruffled by the cylinder, the upper surface opening of the water level detection tank is covered by the lid in a substantially sealed state, so the sealed state inside the cylinder of the water level detection tank There was a new problem that the water level sensor could not detect the water level unless it was resolved.

  In order to eliminate the sealed state of the cylinder of the water level detection tank, a through hole is formed in the peripheral surface of the cylinder at a position higher than the water level, and the inside of the cylinder is communicated with the outside of the cylinder by the through hole. It was considered to make the inside of the cylinder part in an air communication state via the outside of the cylinder part and the overflow part. However, the through hole in the cylinder of the water level detection tank may be blocked by the adhesion of the scale contained in the water, and if the inside of the cylinder of the water level detection tank does not open to the atmosphere, the water level sensor Could not detect the water level accurately. Also, as described above, the steam flowing from the cooking chamber into the drainage tank may rise up the drainage pipe and flow into the water level detection tank, but the steam flowing in enters the inside of the cylinder through the through hole. Since the water level sensor may be exposed to high temperature steam, it has to adopt an expensive water level sensor having high heat resistance, and there is a problem that the manufacturing cost can not be lowered. The present invention is a cylinder extending downward from the upper wall of the water level detection tank so as to surround the water level sensor in order to prevent water in the water level detection tank from being ruffled by water supplied by the water supply unit around the water level sensor. It is an object of the present invention to ensure that the inside of the cylindrical portion of the water level detection tank can be open to the atmosphere when forming the portion, while preventing the water level sensor from being affected by the external air flowing back from the overflow portion.

In order to solve the above problems, a steam generation container storing water of a predetermined water level, heating means for heating water in the steam generation container, a water level detection tank connected in communication with the lower part of the steam generation container, water level detection A water level sensor provided in the tank for detecting the water level in the steam generation container by detecting the water level inside, a water supply unit provided above the water level detection tank, and an excessive water level in the water level detection tank A steam generating device having a cylindrical overflow portion for discharging water, the water level sensor extending downward from the upper wall portion of the water level detection tank so that the water supply portion and the overflow portion are disposed outside the a rippling prevention tube portion prevents the affected air flowing back from the impact and the overflow portion of waving due to the water supply from the water level sensor water supply unit provided Nde inside circumference, waving the upper wall portion of the water level detection tank There is provided a steam generator, characterized in that the formation of the communication hole to communicate outside and communicates the water level detection tank inside the prevention tubular portion ruffling of the water level detection tank inside position of the stop cylinder portion.

In the steam generator constructed as described above, it extends downwardly from the upper wall portion of the water level detection tank, the water level sensor enclose the water level sensor inside so that the water supply unit and the overflow portion is located outside the water supply Because the wave prevention cylinder is provided to prevent the influence of the water from the water supply and the influence of the air flowing back from the overflow , for example, the water level detection tank should be miniaturized and the water supply part should not be placed near the water level sensor. If the water level sensor inside the anti-corruption cylinder is supplied from the water supply section outside the cylinder, it will not be affected by the rippling of the water surface, and the water level sensor will be accurate. It became possible to detect a low water level. In addition, the communication hole is formed inside the wave prevention cylinder in the upper wall of the water level detection tank, so the inside of the cylinder in the water level detection tank is reliably not blocked by the scale component contained in the water. The atmosphere was released, and the water level sensor was able to accurately detect the water level in the water level detection tank. In addition, outside air of various properties may backflow from the overflow section into the water level detection tank, but the backflowed outside air is blocked by the wave prevention cylinder section without flowing around the water level sensor, and the water level sensor It was possible to prevent the influence of external air flowing back into the water level detection tank from the overflow section.

In the steam generator configured as described above, a through hole for mounting a water level sensor is formed in the upper wall of the water level detection tank at the inside position of the anti-corrugation cylinder , and the water level sensor is a part of the upper wall And a stem that extends from the top of the cylindrical mounting portion through the through hole to extend to the inside of the anti-corrosion cylindrical portion of the water level detection tank. And a float supported on the stem so as to move up and down. The water level is detected by detecting the position of the float moved up and down by the buoyancy of water by means of a proximity switch provided on the stem. preferably forms a communication port to the mounting portion, it as such when the proximity switches constituting the water level sensor by the outside air that has flowed into the inside of the anti tubular section waving from the communicating hole of the cylindrical mounting portion is cooled Not high temperature Te, the water level sensor could be prevented from being deteriorated.

In the steam generating apparatus configured as described above, the water level sensor detects two water levels of the upper limit water level and the lower limit water level suitable for generating steam in the steam generation container, and the range of two water levels of the water level sensor It is controlled to supply water from the water supply portion so as to become, and it is preferable to set the lower end position of the wave prevention cylinder portion to a position lower than the lower limit water level. When normal control is performed by the water level sensor so that the water level inside the water level detection tank becomes the water level in the range between the upper limit water level and the lower limit water level, the inside of the wave prevention cylinder section is the outside of the cylinder section and the air Since it does not pass through, the water level sensor can be prevented from being reliably affected by the external air flowing back into the water level detection tank from the overflow portion by the cylindrical portion.

In the steam generating apparatus configured as described above, the lower end position of the anti-corrugation cylinder portion is preferably located above the center of the heat generating portion of the heating means in the vertical direction. When water of an excessive water level is supplied into the water level detection tank and water of an excessive water level is discharged from the overflow section, the overflow section is in a state where air can not pass through by the discharged water, and the water level detection tank is There was a risk that the water in the steam generating container would flow back into the water level detection tank due to negative pressure outside the unit. At this time, there is a possibility that the heat generation part of the heating means is exposed from the water and the inside of the steam generation container becomes empty because water flows back from the steam generation container to the water level detection tank. when the upper half is exposed, becomes lower than the lower end position of the anti-cylinder unit the water level of the water level detection tank is waving, air inside the prevention tube portion ruffling of the water level detection tank becomes a ready passage to the outside The negative pressure on the outside of the wave prevention cylinder in the water level detection tank is eliminated. Elimination of the negative pressure on the outside of the wave prevention cylinder in the water level detection tank prevents water from flowing backward from the steam generation container to the water level detection tank, and prevents the steam generation container from becoming empty. did it.

It is a front view of a cooking-by-heating machine incorporating a steam generator of the present invention. It is sectional drawing of the AA line of FIG. It is a perspective view which shows the rack frame of a cooking chamber. They are a side view (a) and a top view (b) of a steamy generator. It is a longitudinal direction sectional view (a) of FIG. 4 and a BB sectional view (b) of FIG. 4 FIG. 5 is a partially broken sectional view taken along the line CC of FIG. 4; It is drawing equivalent to FIG. 5 (a) of embodiment which formed the communicating hole in the cylindrical attachment part of a water level sensor.

  Below, one Embodiment which applied the steam generator of this invention to heating cookers, such as a steam convection oven, is described with reference to an accompanying drawing. As shown in FIG. 1 and FIG. 2, the heating cooker 10 is a machine room in the space of the left side portion of the housing 11 and the cooking chamber 12 for cooking food in the part excluding the left side portion in the housing 11. It has 13 and. As shown in FIG. 2, the left side in the cooking chamber 12 is a heating space 12a, and a heater 14 for heating the cooking chamber 12 and a blower fan 15 for circulating (convecting) the air in the cooking chamber 12 are provided. A portion other than the heating space 12a is provided as a storage space 12b for storing food. The blower fan 15 is a centrifugal fan such as a sirocco fan, and sends the air drawn from the central portion outward in the centrifugal direction. When the blower fan 15 is driven, air is sucked from the accommodation space 12b as shown by the arrows in FIG. 2, and the air sent outward in the centrifugal direction is heated by the heater 14 and becomes hot air, and the peripheral wall of the cooking chamber 12 It is sent to the accommodation space 12b again along (the front wall, the rear wall, the upper wall and the lower wall).

  As shown in FIG. 2, rack frames 16 are provided on the left and right sides of the storage space 12 b of the cooking cabinet 12 to support trays T receiving food material called a hotel pan in a multistage manner in the vertical direction. As shown in FIG. 3, ten rack frames 16 are bridged between the support columns 16a and 16b erected in the front and rear direction and the support columns 16a and 16b at equally spaced positions in the vertical direction. And a support rail 16c. The front and rear support columns 16a and 16b are formed by bending an elongated sheet metal. The front support column 16a is bent in a U-shape such that the cross-sectional shape in the direction (horizontal direction) orthogonal to the longitudinal direction opens outward. The rear support column 16b is bent at a right angle from the front end of the base 16b1 to the outside of the cooking cabinet 12 from the front end of the base 16b1 whose cross-sectional shape in the direction (horizontal direction) orthogonal to the longitudinal direction extends in the front-rear direction It has a front portion 16b2 and a rear portion 16b3 bent at a right angle from the rear end of the base portion 16b1 to the inside of the cooking cabinet 12 and extended to form a Z shape bent at a right angle. It is bent.

  The support rail 16c extending in the front-rear direction is bent in a U-shape such that the cross-sectional shape in the direction orthogonal to the longitudinal direction (vertical direction extending in the left-right direction) opens inward. As shown in FIG. 3, in the U-shaped groove of the support rail 16c, the flange portion T1 of the upper edge of the tray T such as a hotel pan can be engaged so as to slide in the longitudinal direction. The tray T in which the flange portion T1 is engaged in the U-shaped groove of the support rail 16c engages with the rear portion 16b3 of the rear support column 16b to position the tray T on the rear side in the cooking cabinet 12 It has been done. The rear end of the flange portion T1 of the tray T is engaged with the rear portion 16b3 of the support column 16b to enable the rear side positioning of the tray T in the cooking chamber 12. Therefore, the tray T is formed at the rear portion of the support rail 16c. It is possible to form a symmetrical shape in the front-rear direction without forming the positioning portion of the above, and it is possible to make the support rails 16c common to the left and right rack frames 16. In addition, since the rear support column 16b extends the rear portion 16b3 to the inside of the cooking chamber 12, as shown by the arrows in FIG. 2, it was sent along the rear wall of the cooking chamber 12 from the blower fan 15. The air was not blocked by the rear 16b3 of the rear support post 16b.

  As shown in FIG. 2, a steam generator 20 for supplying steam into the cooking cabinet 12 is provided at the rear of the machine room 13. As shown in FIGS. 3 and 4, the steam generating apparatus 20 includes a steam generating container 21 storing water of a predetermined water level, a heating unit 30 for heating water in the steam generating container 21, and the steam generating container 21. It is provided in the water level detection tank 23 for detecting the water level in the steam generation container 21 by communicating connection to the lower part of the lower part, and the water level in the steam generation container 21 by detecting the water level inside. And a cylindrical overflow portion 24 c for discharging water of an excessive water level in the water level detection tank 23.

  As shown in FIG. 4 and FIG. 5, the steam generating container 21 has a cylindrical shape whose upper and lower sides are open. The opening 21a at the upper end of the steam generating container 21 is a steam spouting port, and the opening 21b at the lower end of the steam generating container 21 is a drainage port. Connected to the upper portion of the steam generating container 21 is a steam lead-out cylinder 22 for feeding steam into the cooking chamber 12. A drainage cylinder (not shown) is connected to the lower part of the steam generation container 21. Water in the steam generation container 21 is drained by opening a drainage valve (not shown) provided in the drainage cylinder. . As shown in FIG. 6, a through hole 21 c is formed in the upper part of the circumferential surface of the steam generation container 21, and a temperature sensor 35 for detecting an overheated state of the heating body 31 described later is inserted into the through hole 21 c. It is done.

  As shown in FIG. 5, the steam generating apparatus 20 includes heating means 30 for heating the water in the steam generating vessel 21. The heating means 30 of this embodiment is an induction heating type heating means. The heating means 30 includes a heating body 31 in the steam generation container 21 and an induction heating coil 34 wound from the middle to the lower part in the vertical direction on the outer periphery of the steam generation container 21. The heating body 31 heats the water in the steam generating container 21 by Joule heat generated due to the electric resistance when an eddy current flows under the influence of the magnetic field generated when the high frequency current is supplied to the induction heating coil 34. The heating body 31 includes a substantially annular holder 32 supported on the upper portion of the steam generation container 21, and a plurality of heating rods 33 whose upper end is fixed to the holder 32. The heating rod 33 has a heating portion 33a that generates heat when supplying a high frequency current to the induction heating coil 34 at the same height position as the induction heating coil 34, and a non-heating portion 33b that does not generate heat at a position higher than the heating portion 33a. doing. The heating rod 33 has the upper non-heating portion 33 b attached to the holder 32. As shown in FIG. 6, in one of the plurality of heating rods 33, an insertion hole 33c extending in the radial direction in the non-heat generating portion 33b is formed. The insertion hole 33c is formed at a position facing the through hole 21c of the steam generation container 21, and the temperature sensor 35 inserted from the outside into the through hole 21c of the steam generation container 21 is inserted into the insertion hole 33c. . In addition, although the heating means 30 of this embodiment heats the heating body 31 by induction heating, it is not restricted to this, The heating body by the heater which generates heat by electrical resistance, and the combustion gas by combustion of gas It may be a heater for heating water.

  As shown in FIG. 5, the water level detection tank 23 stands upright at a position adjacent to the steam generation container 21, and the lower part of the water level detection tank 23 is connected to the lower part of the steam generation container 21. The water level detection tank 23 has a tank main body 24 that functions as a container that is open at the top and stores water, and a lid 25 that constitutes the upper wall portion of the water level detection tank 23 and that detachably closes the top opening of the tank main body 24. Have. A through hole 25 a is formed in the central portion of the lid 25 of the water level detection tank 23, and a water level sensor 26 is attached to the water level detection tank 23 so as to pass through the through hole 25 a.

  As shown in FIG. 5, the water level sensor 26 detects the water level in the water level detection tank 23 to detect the water level in the steam generation container 21. The water level sensor 26 forms a part of the upper wall (lid) 25 of the water level detection tank 23 while forming a cylindrical mounting portion 26 a that closes the through hole 25 a, and the cylindrical mounting portion 26 a through the through hole 25 a And a float 26c supported vertically movably on the stem 26b. The stem 26b is provided with a proximity switch 26d such as a reed switch, and a magnet 26e is provided above the float 26c. The water level sensor 26 detects the water level in the water level detection tank 23 by detecting the position of the float 26c moved up and down by the buoyancy of water by the proximity switch 26d of the stem 26b. In this embodiment, the water level sensor 26 includes two proximity switches 26d, and the two proximity switches 26d can detect two water levels of the upper limit water level L1 and the lower limit water level L2. The upper limit water level L1 is a water level substantially the same height position as the heat generating portion 33a of the heating rod 33 in the steam generating container 21, and the lower limit water level L2 is the upper portion of the heat generating portion 33a of the heating rod 33 in the steam generating container 21. A part of the height is exposed from the water.

  A water supply unit 25 b is provided on the lid 25 of the water level detection tank 23, and a water supply pipe 27 derived from a water supply source such as a water supply is connected to the water supply unit 25 b. Water is supplied from the water supply unit 25 b into the water level detection tank 23 by opening the water supply valve (not shown) interposed in the water supply pipe 27. In this embodiment, the water supply unit 25b is provided at a position slightly away from the center of the water level detection tank 23, as shown in FIG. 4 (b).

  As shown in FIG. 5, the bottom wall of the tank body 24 of the water level detection tank 23 is formed with a drainage port 24 a on the side opposite to the steam generation container 21, and the steam generation container of the tank body 24 is formed. A partition 24 b is formed at a position opposite to the side wall opposite to 21. The partition portion 24b and the side wall of the tank main body 24 surround the drainage port 24a to form a cylindrical overflow portion 24c for discharging water at an excessive water level in the water level detection tank 23. A drain pipe 28 is connected to a lower portion of the overflow portion 24 c, and a tip end of the drain pipe 28 is connected to a drain tank (not shown) for receiving drainage from the inside of the cooking chamber 12. Excess water in the water level detection tank 23 flows over the upper edge of the partition 24b into the overflow 24c and is discharged to the drainage tank through the drainage pipe 28. In addition, the overflow part 24c is not restricted to this, A cylindrical member may be used.

As shown in FIGS. 4B and 5, the lid 25 of the water level detection tank 23 is formed with a cylindrical portion (corrugation preventing cylindrical portion) 25c extending downward at the center of the lower surface. The cylindrical portion 25c surrounds the water level sensor 26 so as to dispose the water supply portion 25b and the overflow portion 24c on the outer side. The cylindrical portion 25c has a function to prevent the water surface waved by the water injected from the water supply portion 25b outside the cylindrical portion 25c in the water level detection tank from being transmitted to the water surface around the water level sensor 26 inside the cylindrical portion 25c. doing. In addition, since the cylindrical portion 25c surrounds the water level sensor 26 so that the overflow portion 24c is on the outside, the steam discharged from the cooking chamber 12 to the drainage tank passes through the drainage pipe from the overflow portion 24c to the water level detection tank 23 Even if it flows into the inside, the steam does not flow around the water level sensor 26 by the cylindrical portion 25c.

  The lower end of the cylindrical portion 25c is separated from the bottom wall of the water level detection tank 23, and the inside and the outside of the cylindrical portion 25c communicate with the lower portion of the water level detection tank 23. The lower end position of the cylindrical portion 25c is lower than the lower limit water level L2 detected by the water level sensor 26, and the water level detection tank 23 is of the cylindrical portion 25c also when the lower limit water level L2 is detected by the water level sensor 26. Inside and outside are not allowed to pass air. The lower end position of the cylindrical portion 25 c is a position above the center in the vertical direction of the heat generating portion (heat generating portion) 33 a of the heating rod 33 in the steam generation container 21.

  A communication hole 25d is formed in the lid 25 at a position inside the cylinder 25c, and the communication hole 25d allows the inside of the cylinder 25c in the water level detection tank 23 to communicate with the outside of the water level detection tank 23, and the water level detection tank The inside of the cylindrical portion 25c in the air chamber 23 is open to the atmosphere.

  The operation of the heating cooker 10 configured as described above will be described. The heating cooker 10 operates in a hot air mode in which the heater 14 and the blower fan 15 are operated to cook by hot air, a steam mode in which the blower fan 15 and the steam generator 20 are operated to cook by steam, and the heater 14. , A blower fan 15, and a combination mode in which the steam generator 20 is operated to cook by hot air containing steam.

  When the cooking program of the combination mode is executed in the heating cooker 10, the air in the cooking cabinet 12 circulates as hot air by the operation of the heater 14 and the blower fan 15. Further, steam is supplied into the cooking chamber 12 by the operation of the steam generator 20, and the supplied steam circulates in the cooking chamber 12 together with the hot air from the heater 14 and the blower fan 15. The food contained in the cooking chamber 12 is cooked by the hot air containing the steam.

  When the steam generator 20 is operated, the water supplied from the water supply pipe 27 is injected from the water supply unit 25b into the water level detection tank 23, and the water injected into the water level detection tank 23 flows into the steam generation container 21. Do. Water in the steam generation container 21 is supplied to the upper limit water level L1 based on the water level detected by the water level sensor 26 in the water level detection tank 23.

  In this state, when a high frequency current is supplied to the induction heating coil 34 to cause the heat generating portion 33a of the heating rod 33 to generate heat, the water in the steam generating vessel 21 is heated to become hot water and then further steamed. The steam generated in the chamber 21 blows out from the opening 21 a at the upper end, and is guided into the cooking cabinet 12 by the steam delivery cylinder 22. The water level in the steam generation container 21 gradually decreases due to the generation of steam, and the upper end of the heat generating portion 33a of the heating rod 33 is exposed to water. When the water level sensor 26 detects the lower limit water level L2, a control device not shown The water supplied from the water supply pipe 27 is injected into the water level detection tank 23 from the water supply unit 25 b by opening the water supply valve (not shown) by the control of the control unit 4. The water injected into the water level detection tank 23 flows into the steam generation container 21 and becomes a water level substantially the same as the heat generating portion 33a of the heating rod 33. When the water level sensor 26 detects the upper limit water level L1, a control device not shown The supply of water from the water supply pipe 27 into the water level detection tank 23 is stopped by closing the water supply valve (not shown) by the control of the above. As described above, in the steam generating apparatus 20, the water level in the steam generating container 21 is controlled based on the detected water level of the water level sensor 26 in the water level detection tank 23 to be the water level in the range of the upper limit water level L1 and the lower limit water level L2. ing.

  In addition, when the steam generation apparatus 20 is operated, when the water level in the steam generation container 21 is normally controlled in the range between the upper limit water level L1 and the lower limit water level L2, the heating portion 33a of the heating rod 33 Since the heat is exchanged with the water (hot water) in the steam generation container 21 and the generated steam, the heat does not become overheated. The temperature detected by the temperature sensor 35 when the water level in the steam generation container 21 is normally controlled in the range between the upper limit water level L1 and the lower limit water level L2 is in the range of 100 ° C to 101 ° C.

  On the other hand, when the water level in the steam generation container 21 is not controlled normally and becomes lower than the lower limit water level L2, the heat generating portion 33a of the heating rod 33 sufficiently exchanges heat with water (hot water) and steam in the steam generation container 21. It will overheat without being done. The heat of the overheated state of the heat generating portion 33a is rapidly transmitted to the upper non-heat generating portion 33b, and the temperature of the non-heat generating portion 33b rapidly increases. In this case, when, for example, 104 ° C. or more is detected by the temperature sensor 35, the control device (not shown) stops the supply of high frequency current to the induction heating coil 34, and the inside of the steam generating container 21 becomes dry. I'm preventing.

  When the steam generator 20 is used continuously, scale components adhere to the periphery of the heating rod 33. Heat exchange between the surface of the heat generating portion 33a and the water is not efficiently performed, and the heat of the heat generating portion 33a of the heating rod 33 is easily transmitted to the upper non-heat generating portion 33b. . In this case, even if the water level in the steam generation container 21 is in the above-described normal range, the temperature detected by the temperature sensor 35 gradually rises from 100 ° C.

  For this reason, in the heating cooker 10 of this embodiment, the memory detected by the temperature sensor 35 at the time of steam generation is stored in the controller when the first steam generation operation is performed by the steam generator 20 after the power is turned on. Each time the power is turned on, the unit (not shown) is continuously stored. The temperature detected by the temperature sensor 35 when the steam generator 20 is operated for steam generation gradually rises due to heating by the heat generating portion 33a of the heating rod 33, and around 100 ° C. (or scale adheres when steam is generated) When you do, the temperature becomes almost constant at a little higher than this). Therefore, as in the case of generating steam, the temperature detected by the temperature sensor 35 is stored in the storage unit of the control device (not shown) when the temperature change before and after 10 seconds is within ± 0.2 ° C. Let's do it. When the temperature stored in the storage unit of the control device (not shown) is, for example, 102 ° C. or higher as a predetermined temperature higher than around 100 ° C., it is determined that the scale component is deposited (excessively attached) on the heating rod 33 Preferably, the heating rod 33 is alerted by notifying that the scale component has been deposited. Further, in the steam generating device 20, the calorific value of the heat generating portion 33a of the heating rod 33 changes according to the current supplied to the induction heating coil 34, and the amount of steam generated from the steam generating container 21 can also be changed. By providing the corresponding temperature according to the current supplied to the induction heating coil 34, when the temperature detected by the temperature sensor 35 is different from the corresponding temperature, it is assumed that the scale component is deposited (adheres excessively) to the heating rod 33 It is preferable that the heating rod 33 be alerted to notify that the scale component has been deposited.

  In the steam generator 20 configured as described above, the water level sensor 26 extends downward from the lid 25 serving as the upper wall portion of the water level detection tank 23, and the water supply portion 25b and the overflow portion 24c are disposed outside. The cylinder part 25c which encloses was provided. Even when the water level detection tank 23 is miniaturized and the water supply unit 25b must be disposed at a position close to the water level sensor 26 as in the steam generator 20 of the embodiment of the present application, the water level sensor 26 The water level sensor 25 can detect the water level accurately by the water level sensor 26 because the water level sensor 25 does not receive the influence of the water surface generated when the water is supplied from the water supply unit 25b. Further, since the communication hole 25d is formed on the inside of the cylindrical portion 25c in the lid 25 of the water level detection tank 23, the inside of the cylindrical portion 25c in the water level detection tank 23 is blocked by the scale component contained in water. Because the air was released to the atmosphere without fail, the water level in the water level detection tank 23 could be accurately detected by the water level sensor 26. Further, the overflow portion 24c is connected to a drainage tank for discharging water in the cooking chamber 12 through the drainage pipe 28, and air containing steam from the cooking chamber 12 flows into the drainage tank Because of this, the air containing the steam that has flowed into the drainage tank may rise into the drainage pipe 28 and the overflow portion 24 c and flow into the water level detection tank 23. However, since the high temperature air containing the steam which flowed into the water level detection tank 23 does not flow around the water level sensor 26 by the cylindrical portion 25c, the water level sensor 26 is not affected by the high temperature air containing the steam We were able to.

  Further, the water level sensor 26 detects the two water levels of the upper limit water level L1 and the lower limit water level L2 suitable for steam generation in the steam generation container 21, and becomes the range of the two water levels L1 and L2 of the water level sensor 26. It controls so that water may be supplied from the water supply part 25b. In the steam generating device 20, the lower end position of the cylindrical portion 25c is set to a position lower than the lower limit water level L2 detected by the water level sensor 26. When the water level in the water level detection tank 23 is controlled to a water level in the range between the upper limit water level L1 and the lower limit water level L2, the inside of the cylindrical portion 25c in the water level detection tank 23 is the outer side of the cylindrical portion 25c. Air will not pass through. Thus, in the normal operation state in which the water level in the steam generation container 21 is controlled to be the water level between the upper limit water level L1 and the lower limit water level L2, the water level sensor 26 ascends the overflow portion 24c described above. Thus, it is possible to ensure that the influence of the high temperature air containing the steam backflowed into the water level detection tank 23 is not received.

  Further, the lower end position of the cylindrical portion 25 c of the water level detection tank 23 is located above the center of the heat generating portion 33 a of the heating rod 33 in the vertical direction. When water at an excessive water level is supplied into the water level detection tank 23 and water at an excessive water level is discharged from the overflow portion 24 c due to a failure in the water supply valve or a failure in control of the water supply valve, the overflow portion 24 c There is a possibility that air can not pass through the discharged water, and the inside of the water level detection tank 23 has a negative pressure outside the cylindrical portion 25c, and the water in the steam generating container 21 may backflow into the water level detection tank 23. At this time, since the water flows backward from the steam generation container 21 to the water level detection tank 23, the heat generating portion 33a of the heating rod 33 may be exposed from the water, and the inside of the steam generation container 21 may become empty. However, when the upper half of the heating portion 33 a of the heating rod 33 is exposed, the water level in the water level detection tank 23 becomes lower than the lower end position of the cylinder 25 c, and the air inside the cylinder 25 c in the water level detection tank 23 Is able to pass to the outside, and the negative pressure on the outside of the cylindrical portion 25c in the water level detection tank 23 is eliminated. By eliminating the negative pressure on the outer side of the cylindrical portion 25c in the water level detection tank 23, the water does not flow back from the steam generation container 21 to the water level detection tank 23, and the steam generation container 21 does not run dry. We were able to.

  In the steam generator 20 configured as described above, the communication hole 25d is formed at a position inside the cylindrical portion 25c of the lid 25 that constitutes the upper wall portion of the water level detection tank 23. The present invention is not limited to this, and as shown in FIG. 8, a through hole for mounting the water level sensor 26 inside the cylindrical portion 25 c of the lid 25 constituting the upper wall portion of the water level detection tank 23 In the embodiment in which the water level sensor 26 is attached so as to be inserted through the through hole 25a, the cover 25 is provided so as to protrude above the cover 25 so as to close the through hole 25a while configuring a part of the cover 25. The communication hole 26 f may be formed in the cylindrical attachment portion 26 a of the water level sensor 26. In this case, the proximity switch constituting the water level sensor 26 is cooled by the outside air flowing from the communication hole 26f of the cylindrical attachment portion 26a to the inside of the cylindrical portion 25c, thereby preventing the water level sensor 26 from deteriorating. I was able to.

 DESCRIPTION OF SYMBOLS 20 ... Steam generation apparatus, 21 ... Steam generation container, 23 ... Water level detection tank, 24b ... Overflow part, 25 ... Upper wall part (lid body), 25a ... Through hole, 25b ... Water supply part, 25c ... Tube part, 25d, 26d: communicating hole, 26: water level sensor, 26a: cylindrical mounting portion, 26b: stem, 26c: float.

Claims (4)

A steam generating container storing water at a predetermined water level,
Heating means for heating the water in the steam generation container;
A water level detection tank connected in communication with a lower portion of the steam generation container;
A water level sensor which is provided in the water level detection tank and detects the water level in the steam generating container by detecting the water level inside;
A water supply unit provided at an upper portion of the water level detection tank;
A steam generating device including a cylindrical overflow portion for discharging water of an excessive water level in the water level detection tank,
Extending downwardly from the upper wall of the water level detection tank, it affects the said water level sensor enclose the water level sensor inside so as to place the said overflow portion and the water supply portion to the outside of waving due to the water supply from the water supply unit And a wave prevention cylinder portion for preventing the influence of air flowing back from the overflow portion ,
The upper wall portion of the water level detection tank is formed with a communication hole at the inside position of the wave prevention cylinder portion , which connects the inside of the wave prevention cylinder portion in the water level detection tank with the outside of the water level detection tank. Steam generator. In the steam generator according to claim 1,
In the upper wall portion of the water level detection tank, a through hole for mounting the water level sensor is formed at an inner position of the wave prevention cylinder portion ,
The water level sensor forms a cylindrical mounting portion which is mounted on the upper side of the upper wall so as to close the through hole while forming a part of the upper wall, and the through hole from the cylindrical mounting portion Proximity switch provided on the stem with the position of the float vertically moved by the buoyancy of water, comprising: a stem extending inside the cylindrical portion of the water level detection tank through the The water level is detected by detecting the water level, and the communication hole is formed in the cylindrical attachment portion. The steam generator according to claim 1 or 2
The water level sensor detects two water levels in the steam generation container, an upper water level and a lower water level suitable for generating steam,
It is controlled to supply water from the water supply section so as to be within the range of two water levels of the water level sensor,
The lower end position of the wave prevention cylinder part is a position lower than the lower limit water level. The steam generator according to any one of claims 1 to 3,
The lower end position of the wave prevention cylinder part is a position above the center in the vertical direction of the heat generating portion of the heating means.

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