JP2007054647A - Pressure rice cooker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure rice cooker that can finely adjust pressure to be applied when cooking rice. <P>SOLUTION: The pressure rice cooker is provided with a pressure adjusting device 15 having a blocking valve 20b which blocks an exhaust vent 20c, a pressing section 21b which applies pressing force to the blocking valve 20b through a spring 21g, an arm section 22 (pressing section moving means) which moves the pressing section 21b in a blocking direction where the pressing section 21b is lead towards a blocking position or in an opening direction where the pressing section 21b is lead towards an opening position, and a stepping motor 23 which can be turned forward and backward to drive the arm section 22, and a microcomputer 8 (controlling means) which increases or decreases the pressure inside an inner pot 2 by moving the pressing section 21b towards the blocking direction or the opening direction by rotating and driving the stepping motor 23 of the pressure adjusting device 15 in a normal direction or a reverse direction based on a signal transmitted from a pressure sensor 13 when cooking rice under pressure. The controlling means, when reducing pressure inside the inner pot 2, turns and drives the stepping motor 23 in the reverse direction during a specified on time and then turns off the stepping motor 23 during a specified off time. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to pressure cookers for home use and business use.

As a pressure rice cooker that cooks at a pressure higher than atmospheric pressure, a rice cooker in which a pressure regulator, which is a pressure mechanism, is arranged in a steam discharge path formed inside a lid that closes the inner pot is known. The pressure regulator includes a steam discharge path communicating with the inner pot, a pressure adjusting ball disposed in the steam discharge path, and a solenoid that is a driving means for the pressure adjusting ball. Before cooking, after cooking, and after cooking, the pressure regulator presses the pressure-regulating ball with a solenoid, retracts from the steam discharge path, and communicates the inside of the pan and the outside of the lid (open state) It has become. In addition, during pressure rice cooking, the steam discharge path is closed by the weight of the ball, so that the internal pressure of the inner pot is increased and the pressure is charged.On the other hand, when the internal pressure of the inner pot exceeds a predetermined pressure, The pressure adjusting ball is lifted and discharged to the outside through a steam hole provided in the lid through a steam discharge path (pressurized state).
JP 2000-287841 A JP 2000-37296 A

  However, the rice cooker has a problem that only a constant pressure can be applied during rice cooking, and fine pressure adjustment cannot be performed.

  Then, this invention makes it a subject to provide the pressure rice cooker which can adjust finely the pressure applied at the time of rice cooking.

As a means for solving the above problems, the present invention provides:
Inner pot,
A main body for accommodating the inner pot;
A lid that is attached to the main body so as to be opened and closed, and seals the inner pot;
Heating means for heating the inner pot;
An exhaust port for discharging the steam in the inner pot provided in the lid,
Pressure detecting means for detecting the pressure in the inner pot;
A blocking valve that closes the exhaust port, a pressing portion that applies a pressing force to the blocking valve via a spring having a predetermined elastic force, and is movable between a blocking position and an opening position; A pressure adjusting device having a pressing portion moving means for moving in the closing direction toward the closing position or in the opening direction toward the opening position, and a stepping motor capable of rotating forward and backward to drive the pressing portion moving means;
At the time of pressure rice cooking, based on the signal from the pressure detection means, by rotating the stepping motor of the pressure adjusting device in the normal rotation direction or the reverse direction and moving the pressing portion in the closing direction or the opening direction, Control means for pressurizing or depressurizing the pressure in the inner pot is provided.

  In the said invention, a control means outputs a drive signal to a stepping motor based on the pressure in the inner pot detected by the pressure detection means at the time of pressure rice cooking. When the stepping motor is driven to rotate in the forward direction in accordance with this drive signal, the pressing portion moves in the closing direction. At this time, the pressing portion applies a pressing force to the closing valve that closes the exhaust port via a spring to pressurize the pressure in the inner pot. On the other hand, when the stepping motor is rotationally driven in the reverse direction, the pressing portion moves in the opening direction. At this time, the pressing portion is pushed upward by the pressing force of the spring. As a result, the pressing force by the spring applied to the closing valve is reduced and the pressure in the inner pot is reduced. Thereby, the pressure in an inner pot can be varied.

The control means includes
Set the upper pressure limit and lower pressure limit,
When the pressure value detected by the pressure detection means is not more than the pressure lower limit value, the stepping motor is rotationally driven in the normal rotation direction,
When the pressure value is greater than or equal to the pressure upper limit value, the stepping motor is rotationally driven in the reverse direction,
When the pressure value is not less than the pressure lower limit value and not more than the pressure upper limit value, the stepping motor is preferably turned off. Thereby, the pressure in the inner pot is regulated to a pressure lower limit value or higher and a pressure upper limit value or lower. Moreover, since the stepping motor is turned off within this pressure range, the pressure in the inner pot is maintained at an appropriate pressure value.

  Moreover, it is preferable that the said pressure upper limit and pressure lower limit can be set arbitrarily. Thereby, the cooking method can be changed.

  When the pressure difference between the pressure value detected by the pressure detection means and the pressure upper limit value or the pressure lower limit value is equal to or greater than a predetermined pressure difference, the control means increases the rotation speed of the stepping motor, When the difference is less than the predetermined pressure difference, it is preferable to reduce the rotation speed of the stepping motor. Thereby, when a pressure difference is large (when it is more than a predetermined pressure difference), it can pressurize or reduce pressure quickly to a set pressure. Further, when the pressure difference is small, fine pressure adjustment is possible in the vicinity of the set pressure.

  When the pressure in the inner pot is reduced, the control means may rotate the stepping motor in the reverse direction for a predetermined on time and then turn off the stepping motor for a predetermined off time. preferable. Thereby, the pressure in an inner pot can be pressure-reduced in steps.

  At this time, it is preferable that the on-time and the off-time are set according to the pressure in the inner pot. For example, when the pressure in the inner pot is high, the amount of steam discharged can be reduced if the on-time is set to a short time of 20 ms. In addition, when the pressure in the inner pot is low, the pressure in the inner pot can be quickly reduced if the on-time is set to 500 ms and the off-time is set to 1 s.

  Moreover, it is preferable that the said on time and the said off time are set separately according to each rice cooking menu, each process, or rice cooking capacity.

A clock pulse output circuit that outputs a clock pulse having a predetermined frequency to the control means, and when the pressing portion is moved to the open position, the pressing portion moving means is turned on to come into contact, and the control means Provide a micro switch that outputs a signal to
The control means counts the clock pulse that is output while the stepping motor is rotated in the forward direction or the reverse direction from the time when the microswitch is turned on. It is preferable to add the counted number of clock pulses when rotated in the rotating direction, and to subtract the counted number of clock pulses when rotating the stepping motor in the reversed direction. Thereby, the position of the motor position of the stepping motor can be detected based on the motor position of the stepping motor at the time when the microswitch is turned on.

  When the micro switch is turned on, the control means sets the motor position of the stepping motor to a zero point, and drives the stepping motor to rotate in the forward rotation direction so that the counted value is a positive first predetermined number. It is preferable to set the motor position of the stepping motor when the value becomes the MAX point. At this time, the operation range of the stepping motor can be defined between the zero point and the MAX point. When the micro switch is turned on, the pressing portion is provided so as to be located at the open position. Further, when the stepping motor is rotationally driven in the forward rotation direction so that the motor position of the stepping motor is positioned at the MAX point, the pressing portion is provided so as to be positioned at the closed position.

  At this time, it is preferable that the control means turns off the stepping motor when the count value becomes 0 corresponding to the zero point or the positive first predetermined number corresponding to the MAX point.

  The control unit may turn off the stepping motor when the count value reaches the first positive predetermined number or the negative second predetermined number corresponding to the MAX point.

  It is preferable that the pressing portion moving means is an arm portion that is rotatably provided in conjunction with the output shaft of the stepping motor and is disposed above the pressing portion.

  Preferably, the control means turns off the stepping motor for a predetermined time when the rotation direction of the stepping motor is changed in the reverse direction. By turning off the stepping motor for a predetermined time, it is possible to prevent the stepping motor from slipping when it starts reverse rotation, and it is possible to realize an accurate operation in the pressure regulator.

  Preferably, the control means slows down the initial rotation speed of the stepping motor when starting to rotate the stepping motor or when changing the rotation direction of the stepping motor in the reverse direction. Thereby, a large torque can be obtained as compared with the case of rotational driving at a normal rotational speed.

  As is clear from the above description, in the rice cooker of the present invention, the inner pot, the main body that houses the inner pot, the lid that is attached to the main body so as to be opened and closed, and seals the inner pot, and the inner pot are heated. A heating means, an exhaust port for discharging the steam in the inner pot provided on the lid, a pressure detection means for detecting the pressure in the inner pot, a blocking valve for closing the exhaust port, and a blocking valve A pressing portion that applies a pressing force and is provided so as to be movable between a closed position and an open position; a pressing portion moving means that moves the pressing portion in a closing direction toward the closing position or in an opening direction toward the opening position; And a pressure adjusting device having a stepping motor capable of rotating forward and reverse to drive the pressing unit moving means, and at the time of pressure cooking, based on a signal from the pressure detecting means, the stepping motor of the pressure adjusting device is rotated in the normal rotation direction or the reverse direction. Drive and push By moving the part in the closing direction or the opening direction, it is equipped with a control means to pressurize or depressurize the pressure in the inner pot, so it becomes possible to cook rice with high pressure during cooking, and the pressure to be applied is desired It is possible to provide a pressure cooker that can obtain delicious rice with increased stickiness and sweetness by changing to the pressure of. Moreover, there is also an effect that cooking time can be shortened by cooking with high pressure.

  In particular, the control means sets the pressure upper limit value and the pressure lower limit value, and when the pressure value detected by the pressure detection means is equal to or lower than the pressure lower limit value, the stepping motor is driven to rotate in the forward direction, and the pressure value is the pressure. When it is above the upper limit value, the stepping motor is driven to rotate in the reverse direction, and when the pressure value is above the pressure lower limit value and below the pressure upper limit value, the stepping motor is turned off. The pressure is adjusted appropriately above the lower pressure limit and below the upper pressure limit.

  In particular, when the pressure difference between the pressure value detected by the pressure detection means and the pressure upper limit value or the pressure lower limit value is greater than or equal to a predetermined pressure difference, the control means increases the rotation speed of the stepping motor, and the pressure difference increases to the predetermined pressure. If it is less than the difference, the pressure in the inner pan can be quickly reduced or increased by slowing down the rotation speed of the stepping motor if the pressure difference is large. Further, when the pressure difference is small, fine pressure adjustment is possible.

  When reducing the pressure in the inner pot, the control means rotates the stepping motor in the reverse direction for a predetermined on time and then turns off the stepping motor for a predetermined off time. Can be reduced stepwise.

  Moreover, the ON time and the OFF time are set according to the pressure in the inner pot, thereby producing an effect of reducing the amount of discharged steam or quickly reducing the pressure in the inner pot.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(First embodiment)
FIG. 1 shows a pressure rice cooker 1 according to the first embodiment of the present invention. The pressure cooker 1 includes an inner pot 2, a main body 3 and a lid 4.

  The inner pot 2 is coated on the outer surface of a pot base material made of aluminum or the like having a high thermal conductivity with a ferromagnetic material that is electromagnetically heated by an eddy current generated when a high-frequency current is supplied to the induction heating coil 6 described later. Or joined.

  The main body 3 includes a protective frame 5 made of a non-conductive material that accommodates the inner pot 2 inside a body 3a having a bottomed cylindrical shape. Between the body 3a and the protective frame 5, an induction heating coil 6 as a heating means, a temperature sensor 7 for an inner pot, and a microcomputer 8 as a control means are arranged.

  The induction heating coil 6 is disposed on the lower surface of the protective frame 5 and electromagnetically heats the inner pot 2 when a high frequency current is applied.

  The temperature sensor 7 for the inner pot detects the temperature of the inner pot 2, and is disposed at the bottom of the protective frame 5, and the inner pot 2 passes through a through-hole provided in the protective frame 5 with a detection portion at the tip thereof. The temperature of the inner pot 2 is output to the microcomputer 8.

  The lid 4 closes the opening portions of the inner pot 2 and the main body 3 so as to be openable, and includes a lid upper plate 4a and a lid lower plate 4b. On the inner pot 2 side of the lid 4, a heat radiating plate 9, a lid heater 10 and an inner lid 11 are disposed. In addition, a lid temperature sensor 12, a pressure sensor 13, a relief valve 14, and a pressure regulator 15 are disposed inside the lid 4.

  The lid temperature sensor 12 detects the temperature in the inner pot 2 and outputs the detected temperature to the microcomputer 8.

  The pressure sensor 13 is arranged so that the detection part faces the inside of the inner pot 2, detects the pressure in the inner pot 2, and outputs a voltage value corresponding to the detected pressure to the microcomputer 8. To do.

The relief valve 14 is disposed from above the opening 14a communicating with the inner pot 2, and has a well-known configuration including a pressure adjusting ball 16 that closes the opening 14a by its own weight. The pressure adjusting ball 16 is a metal sphere covered with polypropylene. A vapor discharge path 17 is formed inside the lid body 4 and communicates with the outside of the lid body 4 through the opening 14 a and the steam port 4 c of the lid body 4. At the time of rice cooking, the pressure adjusting ball 16 closes the opening 14a by the weight of the ball while the inner pressure of the inner pot 2 exceeds 0.52 kg / cm ² (1.5 atm), for example, in the inner pot 2 The steam in the inner pot 2 is discharged to the outside. Thereby, when the inside of the inner pot 2 becomes an abnormally high pressure, the internal pressure is released.

  As shown in FIGS. 2 to 4, the pressure adjusting device 15 includes a closing valve portion 20, a closing valve pressing portion 21, an arm portion 22 (pressing portion moving means), and a stepping motor 23.

  The blocking valve portion 20 includes a blocking valve housing portion 20a and a blocking valve 20b. The closing valve accommodating portion 20a is fitted into a mounting hole 11a provided in the inner lid 11 from below, and is engaged with and attached to the lower surface of the edge of the mounting hole 11a. An exhaust port 20c is formed inside the shut-off valve accommodating portion 20a. In addition, a recess 20d for accommodating the blocking valve 20b is formed inside the blocking valve accommodating portion 20a. Three locking claws 20e for locking a later-described case member 21a of the closing valve pressing portion 21 are formed at the upper end of the closing valve accommodating portion 20a.

  The blocking valve 20b is disposed inside the recess 20d of the blocking valve accommodating portion 20a so as to be movable in the vertical direction. Four claw portions 20f for locking the lower end of the spring 21g are provided on the outer periphery of the blocking valve 20b. A shaft portion 20g is provided on the upper surface of the blocking valve 20b.

  The blocking valve pressing portion 21 includes a case member 21a and a pressing portion 21b. The case member 21a has a substantially cylindrical shape with an open lower surface, and an insertion hole 21c through which the upper portion of the pressing portion 21b is inserted is formed on the upper surface. The case member 21a is disposed from above the closing valve portion 20, and a locking claw 21d (shown in FIG. 2) provided on the inner surface of the side wall of the case member 21a is engaged with the locking claw 20e of the closing valve housing portion 20a. By joining, it is attached and fixed to the upper surface of the inner lid 11. The pressing portion 21b has a columnar shape, and is provided with a cylindrical insertion portion 21e extending downward from the lower surface thereof. Further, three guide pieces 21f projecting outward are formed at the lower portion of the pressing portion 21b. The pressing portion 21b is disposed inside the case member 21a. Each guide piece 21f of the pressing portion 21b is slidably provided in a guide groove 20h formed on the inner surface of the side wall of the case member 21a. A shaft portion 20g of the blocking valve 20b is inserted inside the insertion portion 21e of the pressing portion 21b. Thus, the pressing portion 21b is movable in the vertical direction with its upper portion protruding upward from the insertion hole 21c of the case member 21a. A spring 21g is provided between the lower surface of the pressing portion 21b and the upper surface of the blocking valve 20b. The spring 21g presses the closing valve 20b downward to close the exhaust port 20c.

  The periphery of the blocking valve pressing portion 21 is covered with an elastic cap 24 made of elastic rubber or the like. The folded collar portion 24 a formed at the lower portion of the elastic cap 24 is sandwiched between the heat radiating plate 9 and the inner lid 11. A disc-shaped thick portion 24 b is integrally formed on the top of the elastic cap 24. A plurality of circulation ports 24 c are formed in the shoulder portion of the elastic cap 24.

  The arm portion 22 (pressing portion moving means) has an annular portion 22a formed at the center thereof, and L-shaped attachment portions 22b are provided on the lower surfaces of both sides of the annular portion 22a. Both ends of the pressing bar 22c are supported on the mounting portion 22b. The pressing bar 22c has a disk-shaped portion 22d in the middle portion thereof. A protruding portion 22e protruding outward is provided on one side of the ring-shaped portion 22a. As will be described later, the protrusion 22e is for turning on the micro switch 26 when the arm portion 22 is rotated counterclockwise. Further, an arc-shaped rack 22f that meshes with a pinion gear 23b (described later) of the stepping motor 23 is provided at the tip of the arm portion 22. Further, the fulcrum part 22g of the arm part 22 has a disk shape, and a hole 22h is formed in the center part thereof. A fixed shaft 22i fixed to the arm mounting portion 25a of the motor stay 25 is fitted into the hole 22h of the fulcrum portion 22g. The ring-shaped portion 22a of the arm portion 22 is disposed so as to be positioned above the elastic cap 24, and the arm portion 22 is attached to be rotatable about a fixed shaft 22i. The disk-shaped portion 22d of the pressing bar 22c is in contact with or attached to the upper surface of the thick portion 24b at the top of the elastic cap 24.

  The stepping motor 23 is driven to rotate in both directions (forward or reverse direction) as indicated by an arrow P in FIG. The stepping motor 23 is fixed to a motor stay 25, and an output shaft 23a of the stepping motor 23 is provided with a pinion gear 23b fixed integrally with the output shaft 23a. The pinion gear 23b is arranged so as to mesh with the rack 22f of the arm portion 22, and when the stepping motor 23 is driven to rotate in the forward rotation direction or the reverse rotation direction, the arm portion 22 is shown by an arrow Q in FIG. It is driven to rotate in the clockwise direction or counterclockwise direction indicated by. Thereby, the said press part 21b moves to the obstruction | occlusion direction or an open | release direction along the perpendicular direction shown by the arrow R in FIG.

  The stepping motor 23 is connected to the microcomputer 8 via a peripheral circuit 40 shown in FIG. The stepping motor 23 receives an on / off drive signal from the ports p1 to p4 of the microcomputer 8, and is driven according to the drive signal.

  As shown in FIG. 4, the motor stay 25 is fixedly attached to the lid lower plate 4b with screws 25b. A micro switch 26 is provided near the center of the motor stay 25 so as to be positioned above the protrusion 22e of the arm portion 22 in a state where the arm portion 22 is attached to the motor stay 25. In the microswitch 26, when the arm portion 22 rotates counterclockwise and the pressing portion 21b is located at an open position (upper end in the vertical direction) described later, the protrusion 22e of the arm portion 22 abuts. It is arranged to be turned on.

  Further, the closing valve 20b is pressed downward by a spring 21g to close the exhaust port 20c. Further, a vapor discharge path 18 communicating with the outside of the lid body 4 through the exhaust port 20 c and the vapor port 4 c of the lid body 4 is formed inside the lid body 4. When the internal pressure of the inner pot 2 rises during rice cooking, the shut-off valve 20b is pushed up by the steam in the inner pot 2 against the elastic force of the spring 21g, whereby the steam in the inner pot 2 passes through the steam discharge path 18. It is designed to be discharged to the outside.

  An operation panel 19 shown in FIG. 5 is disposed on the upper surface of the lid 4. The operation panel 19 includes a plurality of switches 31 to 35 for inputting rice cooking conditions around a liquid crystal display type display panel 30 disposed in the center.

  The switches 31 to 35 execute the reserved rice cooking menu and the germinated brown rice rice cooking menu, and the rice cooking switch 31 for pressing the reheating function while executing the heat retention function, the desired rice cooking menu and the reservation rice cooking menu. Menu switch 32 for selection, barge switch 33 for pressing when it is desired to end all the operations including the rice cooking operation and the reserved rice cooking operation and enter a standby state, heat retention switch 34 for pressing to perform the heat retention function, This is a good night warming switch 35 for pressing when it is desired to change to the good night warming function. Further, an LED (not shown) is disposed on the back of each of the switches 31, 34, and 35 so that each of the switches 31, 34, and 35 can be turned on or blinked.

  In the center of the display panel 30, a numerical display unit 30a capable of displaying a time of 24 hours, a time display unit 30b representing units such as a warming time, and a minute display unit 30c representing units such as the remaining cooking time. Is provided. In addition, on the upper part of the display panel 30, a triangular display portion for indicating the hardness of rice in the white rice cooking menu “normal”, “soft rice”, “hard” and “white rice rapid”, and “washless rice” ”,“ Curry ”,“ Bento ”,“ Sushimeshi ”,“ Okage ”,“ Cooked rice ”,“ Okayu ”,“ Okowa ”and a menu display unit 30d are provided. Yes. Further, a reheating display portion 30e indicating that reheating is being performed is provided above the numerical value display portion 30a. Also, at the bottom of the display panel 30, a menu display is shown to indicate that four types of healthy rice cooking menus, “separated rice”, “brown rice”, “brown rice activity” and “germinated brown rice” are selected. A portion 30f is provided.

  Below this menu display part 30f, a pictographic display part 30g for displaying the pressure in the inner pot 2 at the time of pressure rice cooking described later in stages is provided. This pictogram display unit 30g increases or decreases the number of pictograms 30h provided on both sides according to the pressure in the inner pot 2 detected by the pressure sensor 13. For example, when the pressure in the inner pot 2 is low, only one pict 30h on both sides of the central part is displayed, and when the pressure regulator 15 or the relief valve 14 is in an abnormally high pressure state, all four are displayed. Pict 30h is displayed. Thereby, since the user can judge the pressure state in the inner pot 2, it can prevent that a user opens the cover body 4 carelessly.

  The microcomputer 8 performs a rice cooking operation by sequentially executing the preheating process, the rice cooking process, the unevenness process, and the heat retaining process according to the stored program in response to inputs from the temperature sensors 7, 12 and the pressure sensor 13 and the like. Is to do. The microcomputer 8 performs pressure regulation control (pressure rice cooking) in accordance with the stored program in accordance with the input from the pressure sensor 13 in the rice cooking process and the unevenness process during the rice cooking operation. FIG. 7 shows a data table 50 stored in the microcomputer 8 used during this control. The data table 50 includes a detected pressure value of the pressure sensor 13, a voltage value output from the pressure sensor 13, and an AD value corresponding to the voltage value. The AD value is displayed in hexadecimal (HEX).

  Next, a driving method in which the microcomputer 8 drives the stepping motor 23 will be described. In the present embodiment, the microcomputer 8 drives the stepping motor 23 by the 1-2 phase excitation method. The 1-2 phase excitation method is an excitation method that alternately performs 1 phase excitation and 2 phase excitation. FIGS. 8A and 8B show drive signals in the 1-2 phase excitation method output from the microcomputer 8. The waveform diagram of is shown. The microcomputer 8 is connected to a clock pulse output circuit 42 (shown in FIG. 6) provided inside or outside the microcomputer 8, and a clock pulse a having a predetermined frequency (in this embodiment, from the clock pulse output circuit 42). The frequency of the clock pulse a is set to 330 pps). The drive signals output from the ports p1 to 4 of the microcomputer 8 by the microcomputer 8 count the input clock pulse a and are output based on the clock pulse a. That is, as shown in FIGS. 8A and 8B, the microcomputer 8 sequentially outputs ON signals from the ports p1 to p4 at a cycle of the clock pulse a × 2. The time for outputting the ON signal is set as the time until the clock pulse a × 3 is counted. In this embodiment, the time until the clock pulse a × 3 is counted is 3 ms × 3 = 9 ms.

  As shown in FIG. 8A, when the microcomputer 8 outputs an ON signal in the order of the ports p1, 2, 3, and 4, the stepping motor 23 is driven to rotate in the forward rotation direction. Further, when the ON signal is output in the order of the ports p4, 3, 2, 1, the stepping motor 23 is driven to rotate in the reverse direction.

  Further, when the stepping motor 23 is rotated in the reverse direction, that is, when the direction of rotational drive from the normal rotation direction to the reverse direction or from the reverse direction to the normal rotation direction is changed, during the predetermined time T1 (until the clock pulse a × 5 is counted) ), An off signal is output to the stepping motor 23. Thereby, when the rotation direction of the stepping motor 23 is changed in the reverse direction, the stepping motor 23 is prevented from slipping, and the stepping motor 23 can be controlled with high accuracy.

  Further, when the rotational driving of the stepping motor 23 is started or when the rotational direction of the stepping motor 23 is changed to the reverse direction, as shown in FIG. 8B, the clock pulse output circuit 42 is lower than normal for a predetermined time T2. A clock pulse a ′ having a frequency may be output. In the present embodiment, the predetermined time T2 is set as a time until the clock pulse a ′ × 7 is counted. As a result, the rotation speed of the stepping motor 23 becomes slower than that described above, and a large torque can be obtained. Further, the rotational speed of the stepping motor 23 may be arbitrarily set by making it possible to arbitrarily change the frequency of the clock pulse a '. Further, the predetermined time T2 for the slow start may be arbitrarily set.

  The microcomputer 8 counts the number of clock pulses a output from the time when the micro switch 26 is turned on while the stepping motor 23 is driven to rotate. In this counting method, when the stepping motor 23 is rotationally driven in the forward rotation direction, the number of clock pulses a counted during the rotational driving is added. When the stepping motor 23 is rotationally driven in the reverse direction, the number of clock pulses a counted during the rotational drive in the reverse direction is subtracted. The microcomputer 8 detects the position of the motor of the stepping motor 23 by referring to the counted value Y. That is, it is possible to detect whether the motor position is at the zero point or how far away from the zero point.

  Further, the microcomputer 8 sets an operation range of the stepping motor 23, and the stepping motor 23 operates between the zero point and the MAX point. As shown in the flowchart of FIG. 9, the microcomputer 8 sets the zero point by first rotating the stepping motor 23 in the reverse direction in step S1, and starting a timer in step S2. Next, in step S3, it is determined whether or not the timer has expired. If it is determined that the timer has not expired (in the case of NO), whether or not the micro switch 26 is turned on in step S4. to decide. If it is determined in step S3 that the timer has expired (in the case of YES), an error display is performed in step S7.

  If it is determined in step S4 that it is turned on (in the case of YES), the stepping motor 23 is turned off in step S5. At this time, as shown in FIG. 2, the arm part 22 rotated in the counterclockwise direction is in a state in which the microswitch 26 is turned on, and the pressing part 21b is located at the open position (vertical upper end). In step S6, the microcomputer 8 sets the current motor position of the stepping motor 23 as a zero point (origin). On the other hand, if it is determined in step S4 that the micro switch 26 is not turned on, the process returns to step S3.

  The microcomputer 8 sets the MAX point by rotating the stepping motor 23 in the normal rotation direction from the state where the stepping motor 23 is positioned at the zero point, and a predetermined number (positive first predetermined number) of clock pulses. The motor position of the stepping motor 23 when the stepping motor 23 is rotationally driven until a is output is set as the MAX point. In the present embodiment, the predetermined number is set to 210 (HEX). At this time, the counted value is 210 (HEX). Further, the arm portion 22 rotates in the clockwise direction in FIG. 2, and the thick portion 24 b of the elastic cap 24 is pushed down to the position indicated by the one-dot chain line in FIG. 2, and the pressing portion 21 b is in the closed position (vertical direction). Located at the bottom.

  Then, the microcomputer 8 turns off the stepping motor 23 when the count value Y becomes 0 (HEX) corresponding to the zero point or 210 (HEX) corresponding to the MAX point. Accordingly, the stepping motor 23 operates from the zero point to the MAX point, and the pressing portion 21 is positioned between the upper end and the lower end in the vertical direction.

  Next, operation | movement by the microcomputer 8 of the said pressure rice cooker 1 is demonstrated.

  First, the user accommodates rice of the desired number of cups and the amount of water required to cook the rice in the inner pot 2, and after setting the inner pot 2 in the main body 3, after the desired rice cooking The rice cooking hardness, cooking time, and the like are set by operating the switches 31 to 35 of the display panel 30, and the rice cooking switch 31 is pressed.

  If it does so, the microcomputer 8 will start a rice cooking flow, as shown to the flowchart of FIG. In step S10, energization of the induction heating coil 6 is started, and preheating is performed by adjusting the temperature so that the temperature of the inner pot 2 is about 50 ° C. (preheating step).

  And when predetermined time passes, the microcomputer 8 will energize with 100% (full power) electric power with respect to the induction heating coil 6 in step S11, and will perform an inside papper process (rice cooking process). In Step S12, when it is judged by the inner pot temperature sensor 7 that the temperature in the inner pot 2 has reached 100 ° C., the energization amount to the induction heating coil 6 is controlled to execute the power control process (rice cooking process). In step S13, the induction heating coil 6 is energized again with 60 to 70% power, and the temperature in the inner pot 2 is raised to 100 ° C. or higher to perform the cooking process (rice cooking process).

  When the microcomputer 8 detects dry-up by a well-known method, the microcomputer 8 starts energizing the lid heater 10 disposed on the lid body 4 in step S14, and performs steaming and dew condensation (unevening process) for a predetermined time. And the microcomputer 8 transfers to a heat retention process similarly to a well-known pressure rice cooker in step S15 (heat retention process).

  The microcomputer 8 performs a motor origin return operation at the start of the preheating process. At this time, the microcomputer 8 rotates the stepping motor 23 in the reverse direction and positions the stepping motor 23 at the zero point. The microcomputer 8 turns off the stepping motor 23 when the motor origin return operation is completed.

  The microcomputer 8 performs pressure regulation control as shown in the flowcharts of FIGS. 11 and 12 during the middle pappa process, the power control process, the cooking process, and the unevenness process. First, the microcomputer 8 sets the pressure upper limit value A and the pressure lower limit value B in step S20. The pressure upper limit value A and the pressure lower limit value B are set based on the data table 51 stored in the microcomputer 8 shown in FIG. This data table 51 is usually composed of a pressure upper limit value A and a pressure lower limit value set for each process of the middle pappa, power control, cooking and unevenness in each rice cooking menu of simmering, softening, rapid and brown rice. It has a value B (AD value). The microcomputer 8 sets the pressure upper limit value A and the pressure lower limit value B to 42 and 3E (HEX), respectively, based on the data table 51, for example, when the middle paddy process is normally performed.

  Next, in step S21, the microcomputer 8 takes in an AD value C corresponding to the voltage value output from the pressure sensor 13 based on the data table 50 shown in FIG. This AD value C represents the current pressure value in the inner pot 2. In step S22, it is determined whether or not the current value C of the pressure sensor 13 is equal to or lower than the pressure lower limit value B. If the current value C is equal to or lower than the pressure lower limit B, it is determined in step S23 whether or not the motor position of the stepping motor 23 is located at the MAX point (position detection). At this time, the microcomputer 8 makes a determination by referring to the count value Y added or subtracted according to the rotation direction of the stepping motor 23 as described above. That is, it is determined whether or not the count value Y is 210 (HEX). If it is not the MAX point, the stepping motor 23 is rotationally driven in the normal rotation direction in step S24, and if it is the MAX point, the stepping motor 23 is turned off in step S26.

  And in step S25, like the conventional pressure rice cooker, when the completion conditions in each process are satisfy | filled, pressure regulation control is complete | finished and it transfers to the following process. If the pressure adjustment control is not terminated here, the process returns to step S21.

  As described above, when the stepping motor 23 is rotationally driven in the forward rotation direction, the arm portion 22 is rotated, and the pressing portion 21b of the closing valve pressing portion 21 is pushed down in the closing direction. The pressing part 21b presses the closing valve 20b downward via a spring 21g having a predetermined elastic force attached to the lower surface. At this time, the closing valve 20b is applied with a pressing force by the compressed spring 21g and closes the exhaust port 20c. As a result, the inside of the inner pot 2 is sealed and pressurized until the pressure lower limit B is reached.

  On the other hand, if the current value C of the pressure sensor 13 is greater than or equal to the lower pressure limit B (NO) in step S22, whether or not the current value C of the pressure sensor 13 is greater than or equal to the upper pressure limit A in step S27. Judging. When the current value C of the pressure sensor 13 is not equal to or higher than the pressure upper limit value A (in the case of NO), the stepping motor 23 is turned off in step S28, and the process proceeds to step S25. Thereby, the blocking valve 20b is maintained in a state where a pressing force is applied by the spring 21g. As a result, the pressure in the inner pot 2 is maintained at the pressure lower limit B or higher and the pressure upper limit A or lower.

  If the current value C of the pressure sensor 13 is greater than or equal to the pressure upper limit value A (in the case of YES) in step S27, it is determined whether or not the microswitch 26 is turned on in step S29 shown in FIG. If not, the process proceeds to step S30. In step S30, it is determined whether or not the motor position of the stepping motor 23 is located at the zero point (position detection). At this time, the microcomputer 8 makes a determination by referring to the count value Y added or subtracted according to the rotation direction of the stepping motor 23 as described above. That is, it is determined whether or not the count value Y is 0 (HEX). If it is not the zero point, in step S31, the stepping motor 23 is rotationally driven in the reverse direction, and the process proceeds to step S25 (shown in FIG. 11).

  That is, when the stepping motor 23 is rotationally driven in the reverse direction, the arm portion 22 is rotated counterclockwise, and the pressing portion 21b of the blocking valve pressing portion 21 is pressed upward by the spring 21g and moved in the opening direction. To do. At this time, since the pressing force applied by the spring 21g is reduced, the closing valve 20b is pressed upward by the steam in the inner pan 2 in a high pressure state. As a result, the exhaust port 20c is opened, and the pressure in the inner pot 2 is reduced (released) until the pressure becomes the pressure upper limit value A or less.

  If the motor position is at the zero point in step S30, the stepping motor 23 is turned off in step S33, and the process proceeds to step S25. If the micro switch 26 is turned on in step S29, the current position of the stepping motor 23 is reset to the zero point in step S32. At this time, the count value Y is reset to 0 (HEX). In step S33, the stepping motor 23 is turned off, and the process proceeds to step S25. Thus, even when the zero point is shifted due to slippage generated in the stepping motor 23, accurate control can be performed by newly setting the zero point.

  Thus, the microcomputer 8 controls the pressure regulating device 15 so that the pressure in the inner pot 2 is appropriately regulated to the pressure lower limit value B or more and the pressure upper limit value A or less. Thus, by applying pressure during cooking, delicious rice with increased stickiness and sweetness can be cooked.

  When the microcomputer 8 shifts to the heat retaining step, the microcomputer 8 notifies the end of rice cooking and returns the stepping motor 23 to the zero point as shown in the flowchart of FIG. First, in step S50, the stepping motor 23 is rotationally driven in the reverse direction, and in step S51, a timer is started. Next, in step S52, it is determined whether or not the timer has expired. If it is determined that the timer has not expired (in the case of NO), whether or not the micro switch 26 is turned on in step S53. to decide. When it is determined in step S52 that the timer has expired (in the case of YES), an error display is performed in step S55.

  If it is determined in step S53 that the power is turned on (in the case of YES), the stepping motor 23 is turned off in step S54. At this time, the arm portion 22 rotated in the counterclockwise direction is positioned in a state where the microswitch 26 is turned on as shown in FIG. On the other hand, if it is determined in step S53 that the micro switch 26 is not turned on, the process returns to step S52. Thereby, when attaching the inner lid | cover 11, attachment operation can be performed smoothly, without the arm part 22 pressing the press part 21b. Similarly, when the mode is shifted to the cancel mode, it is preferable that the stepping motor 23 is similarly returned to the zero point.

  Moreover, as shown in the said data table 51, the cooking method can be changed by changing the set pressure upper limit value and pressure lower limit value according to each rice cooking menu. Moreover, you may make it aim at shortening of rice cooking time by changing the pressure upper limit A to a large value, and cooking rice by applying a higher pressure.

  As a modification of the embodiment, a pressure adjusting device 15 ′ as shown in FIGS. 15A and 15B may be provided. The pressure adjusting device 15 ′ has an arm portion 22 ′ having a fulcrum portion 22 g provided at the center. The arm portion 22 'is attached so as to be rotatable about a fixed shaft 22i. Further, one end 22j located on the left side of FIG. 15 of the arm portion 22 'is in contact with or fixed to the upper surface of the pressing portion 21b.

  As the stepping motor 23 is driven to rotate in the forward direction or the reverse direction as indicated by an arrow P in FIG. 15, the arm portion 22 ′ rotates in the counterclockwise direction or the clockwise direction indicated by the arrow Q. It is designed to be driven. Thus, the pressing portion 21b moves in the closing direction or the opening direction along the vertical direction indicated by the arrow R in FIG.

  Further, the micro switch 26 is provided so as to be positioned near the center of the arm portion 22 ′ with the arm portion 22 ′ attached to the motor stay 25.

  As another modification of the embodiment, as shown in FIG. 16 (a), instead of providing the pictograph display part 30g of the display panel 30, a numerical value display part 30a for displaying the time of the display panel 30 is provided. You may make it form a block using and display the pressure in the inner pot 2 in steps. FIG. 16A shows that the numerical display unit 30a is in a high pressure state by three steps from the normal pressure state. Moreover, as shown in FIG.16 (b), you may make it display numerically the pressure in the inner pot 2 by the numerical display part 30a at the time of pressure regulation control.

  As another modification of the embodiment, when the stepping motor 23 is rotationally driven during the pressure adjustment control, a speed variable process may be performed as shown in the flowchart of FIG. This variable speed process is performed when the inside of the inner pot 2 is pressurized or depressurized, that is, when the stepping motor 23 is driven to rotate in the normal rotation direction or the reverse direction during the pressure adjustment control.

  In this speed variable process, is the pressure difference between the pressure value C detected by the pressure sensor 13 and the pressure upper limit value A or the pressure lower limit value B in step S41 equal to or greater than 0.3 atm (predetermined pressure difference)? Judge whether or not. When the pressure difference is 0.3 atm or more, in step S42, the frequency of the clock pulse a is set to 500 pps, which is higher than the normal frequency 330 pps. On the other hand, if the pressure difference is less than 0.3 atm in step S41 (in the case of NO), the frequency of the clock pulse a is set to 100 pps, which is lower than the normal frequency 330 pps, in step S43. As described above, when the clock pulse a is set to a frequency of 500 pps, the rotation speed of the stepping motor 23 is higher than that in the normal state. When the clock pulse a is set to a frequency of 100 pps, the rotation speed of the stepping motor 23 is increased. Slower than normal.

  When the pressure difference to the pressure upper limit value A or the pressure lower limit value B is large (0.3 atmospheric pressure or more), the rotation speed of the stepping motor 23 is set faster than usual, and accordingly, the blocking valve is pressed. The moving speed of the pressing part 21b of the part 21 is also increased. As a result, the detected pressure C in the inner pot 2 is quickly depressurized or pressurized until it reaches the pressure upper limit value A or the pressure lower limit value B. Further, when the pressure difference up to the pressure upper limit value A or the pressure lower limit value B is small (less than 0.3 atm), the rotation speed of the stepping motor 23 is set slower than usual, so that the blockage is blocked accordingly. The moving speed of the pressing part 21b of the valve pressing part 21 also becomes slow. As a result, when the pressure in the inner pot 2 is close to the pressure upper limit value A or the pressure lower limit value B, fine pressure adjustment is possible.

  Next, other embodiments will be described. The same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof will be omitted.

(Second Embodiment)
The stepping motor 23 of the pressure rice cooker 1 according to the second embodiment of the present invention differs from the operation range of the first embodiment (the count value Y is 0 (HEX) to 210 (HEX)), and −315 (HEX). ) (Negative second predetermined number) to 210 (HEX) (positive first predetermined number) is set so as to be rotationally driven. That is, the stepping motor 23 is set so as to operate also in the negative region.

  18 and 19 are flowcharts of the pressure control at this time. Unlike the pressure regulation control of the first embodiment shown in FIGS. 11 and 12, in step S27-1, it is determined whether or not the motor position of the stepping motor 23 exceeds a negative allowable value (−315 (HEX)). Judgment (position detection). At this time, the microcomputer 8 makes a determination by referring to the count value Y indicating the motor position of the stepping motor 23. That is, it is determined whether or not the count value Y is −315 (HEX) or less. In step S27-1, when the count value Y does not exceed the negative allowable value (in the case of NO), the process proceeds to step S29. On the other hand, when the count value Y exceeds the negative allowable value (in the case of YES), the process proceeds to step S27-2 and the stepping motor 23 is turned off.

  Further, unlike the pressure regulation control of the first embodiment, the step S30 in the first embodiment is not provided. That is, even when the motor position of the stepping motor 23 is the zero point, the stepping motor 23 is rotationally driven in the reverse direction in step S31 without turning off the stepping motor 23.

  For example, when the motor position of the stepping motor 23 is in the positive region, noise enters the micro switch 26 and erroneously detects that the micro switch 26 is turned on, or slips in the rotational operation of the stepping motor 23 during pressure regulation control. In such a case, the zero point is set within the operation range of the stepping motor 23 which is the positive region 0 (HEX) to 210 (HEX). At this time, by the pressure adjustment control, even when the motor position of the stepping motor 23 reaches the zero point, the stepping motor 23 can be continuously driven to the negative region. As a result, the stepping motor 23 can be returned to the correct zero point. Note that the negative operating range has an area 1.5 times the positive operating range so that the stepping motor 23 can return to the correct zero point even if the zero point is erroneously set near the MAX point. Is set.

(Third embodiment)
20 and 21 show flowcharts of pressure regulation control of the pressure cooker 1 according to the third embodiment of the present invention. Unlike the pressure regulation control of the first embodiment shown in FIGS. 11 and 12, when the pressure value in the inner pot 2 detected by the pressure sensor 13 is 1.0 to 1.09 atm in step S31-1. In step S31-2, the stepping motor 23 is rotationally driven (turned on) in the reverse direction for 500 ms. In step S31-3, the stepping motor 23 is turned off for 1 s.

  Moreover, in Step S31-1, when the pressure value in the inner pot 2 is 1.1 to 1.19 atm, the process proceeds to Step S31-4, and the stepping motor 23 is rotationally driven in the reverse direction for 100 ms (ON). In step S31-5, the stepping motor 23 is turned off for 3 seconds.

  Moreover, in step S31-1, when the pressure value in the inner pot 2 is 1.2-1.3 atmospheres, it progresses to step S31-6, and the stepping motor 23 is rotationally driven in the reverse direction for 20 ms (ON). In step S31-7, the stepping motor 23 is turned off for 5 seconds.

  Thus, in the pressure rice cooker 1 according to the third embodiment, the stepping motor 23 is rotationally driven (ON) in the reverse direction for 500 ms, 100 ms, or 20 ms (predetermined ON time), and then 1 s, 3 s, or 5 s. During the (predetermined off time), the stepping motor 23 is turned off. Thereby, on / off of the stepping motor 23 is repeated, and the pressure in the inner pot 2 is reduced stepwise.

  Further, the time for rotationally driving the stepping motor 23 is changed according to the pressure in the inner pot 2. When the pressure in the inner pot 2 is high (1.2 to 1.3 atm), the stepping motor 23 is driven to rotate in the reverse direction for a short time of 20 ms, so that it is discharged to the steam discharge path 18 through the exhaust port 20c. The amount of steam generated can be reduced, and the momentum of the steam discharged to the outside of the lid 4 can be weakened. Thereby, the danger that a user gets burned with the vapor | steam discharged | emitted from the steam port 4c of the cover body 4 can be avoided, and safety improves.

  When the pressure in the inner pot 2 is low (1.0 to 1.09 atm), the stepping motor 23 is driven to rotate in the reverse direction for 500 ms, and the time for turning off the stepping motor 23 is only for 1 s. Because there is, the pressure in the inner pot 2 can be quickly reduced. By reducing the pressure in a short time in this way, it is possible to skip excess water adhering to the surface of the rice, particularly during the unevenness process, and to cook deliciously. In the unevenness process, the pressure adjustment control may be terminated when the detected pressure value in the inner pot 2 reaches 1.0 atm.

  Moreover, you may set individually the ON time which rotationally drives the said stepping motor 23 to a reverse direction, and the time which turns OFF the stepping motor 23 according to each rice cooking menu, each process, or rice cooking capacity.

(Fourth embodiment)
FIG. 22 shows a pressure cooker 1 according to the fourth embodiment of the present invention. The pressure rice cooker 1 includes a fan 60 and a hybrid power supply IC (HIC) 61, and other structures are the same as those in the above embodiment.

  The fan 60 is disposed between the body 3a and the protective frame 5 and forcibly sucks outside air from an intake port (not shown) during the rice cooking operation, and the microcomputer 8 is disposed at the opposite position. The outside air is directly applied to the device to cool the elements of the microcomputer 8.

  The hybrid power supply IC 61 generates a DC output from a 100 V AC power supply 61a and supplies the current to the fan 60, the stepping motor 23, the microcomputer 8, and the like. The current capacity of the hybrid power supply IC 61 is 200 mA, and a current of 200 mA or more cannot be supplied. The current required for driving the fan 60 is 130 mA, and the drive current required for the stepping motor 23 is 60 mA. The drive current required by the microcomputer 8 and other members is 40 mA.

  Next, the rice cooking operation | movement by the microcomputer 8 of the said pressure rice cooker 1 is demonstrated.

  As shown in the flowchart of FIG. 23, the microcomputer 8 energizes the fan 60 with a current of 130 mA and drives (turns on) the fan 60 in step S70. In step S71, energization of the induction heating coil 6 is started, and preheating is performed by adjusting the temperature so that the temperature of the inner pot 2 is about 50 ° C. (preheating step). At this time, the total value of the required current is 170 mA used by the fan 60, the microcomputer 8, and other members.

  And when predetermined time passes, the microcomputer 8 will energize with 100% (full power) electric power with respect to the induction heating coil 6 in step S72, will perform an inside papper process, Then, the temperature sensor for inner pots When it is determined by 7 that the temperature in the inner pot 2 has reached 100 ° C., the amount of current supplied to the induction heating coil 6 is controlled to execute the power control process (pressure regulation mode). The microcomputer 8 performs pressure regulation control similar to that of the above embodiment during the middle papper process and the power control process in this pressure regulation mode.

  In step S73, it is determined whether or not the pressure adjustment mode has ended. When the pressure adjustment mode is being executed (NO in step S73), the stepping motor 23 is turned on in step S77. Determine whether or not. If the stepping motor is on, the fan 60 is turned off in step S78, and the process returns to step S73. On the other hand, if the stepping motor 23 is not turned on, the fan 60 is driven (turned on) in step S79. Then, the process returns to step S73.

  At this time, the total value of the required current is 100 mA used by the stepping motor 23, the microcomputer 8, and other members when the stepping motor 23 is driven. When the stepping motor 23 is not driven, the current is 170 mA used by the fan 60, the microcomputer 8, and other members. Therefore, the current capacity of the hybrid power supply IC 61 does not exceed 200 mA. Therefore, since a power supply IC having a current capacity of 200 mA or more is not required, an increase in cost and an increase in size can be avoided.

  When the pressure adjustment mode is completed (YES in step S73), in step S74, the induction heating coil 6 is energized again with 100% (full power), and the temperature in the inner pot 2 is set to 100. Raise to ℃ and execute cooking process. At this time, the fan 60 is driven.

  When the microcomputer 8 detects dry-up by a well-known method, in step S75, the microcomputer 8 starts energizing the lid heater 10 disposed on the lid body 4, and performs steaming and dew condensation (unevening process) for a predetermined time. At this time, the fan 60 is driven. And the microcomputer 8 transfers to a heat retention process similarly to a known pressure rice cooker in step S76 (heat retention process).

It is the schematic of the pressure rice cooker which concerns on 1st Embodiment of this invention. (A) is an enlarged view of the pressure regulator of FIG. (B) is a top view of (a). It is a disassembled perspective view of the pressure regulator of FIG. It is a perspective view of the cover body of FIG. It is a front view of the operation panel of FIG. It is a drive circuit diagram of the stepping motor of the pressure rice cooker of FIG. It is a data table memorize | stored in the microcomputer of FIG. (A), (b) is a wave form diagram of the drive signal for driving the stepping motor output from a microcomputer. It is a flowchart which shows the zero point setting control of a pressure rice cooker. It is a flowchart which shows the rice cooking control of a pressure rice cooker. It is a flowchart which shows pressure regulation control of the pressure rice cooker which concerns on 1st Embodiment of this invention. It is a flowchart which shows pressure regulation control of the pressure rice cooker which concerns on 1st Embodiment of this invention. It is a data table used at the time of pressure regulation control. It is a flowchart which shows the zero point return process of a pressure rice cooker. (A) is the side view which showed the modification of the pressure regulator of FIG. (B) is a top view of (a). (A), (b) is the front view which showed the modification of the operation panel of FIG. It is a flowchart which shows the speed variable process of the pressure rice cooker which concerns on this invention. It is a flowchart which shows pressure regulation control of the pressure rice cooker which concerns on 2nd Embodiment of this invention. It is a flowchart which shows pressure regulation control of the pressure rice cooker which concerns on 2nd Embodiment of this invention. It is a flowchart which shows pressure regulation control of the pressure rice cooker which concerns on 3rd Embodiment of this invention. It is a flowchart which shows pressure regulation control of the pressure rice cooker which concerns on 3rd Embodiment of this invention. It is the schematic of the pressure rice cooker which concerns on 4th Embodiment of this invention. It is a flowchart which shows the rice cooking control of the pressure rice cooker of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Pressure cooker 2 ... Inner pan 3 ... Main body 4 ... Cover body 6 ... Induction heating coil (heating means)
8 ... Microcomputer (control means)
13 ... Pressure sensor (pressure detection means)
DESCRIPTION OF SYMBOLS 15 ... Pressure regulating device 20b ... Blocking valve 20c ... Exhaust port 21b ... Pressing part 21g ... Spring 22 ... Arm part (Pressing part moving means)
22g ... fulcrum 23 ... stepping motor 26 ... micro switch 42 ... clock pulse output circuit

Claims (9)

Inner pot,
A main body for accommodating the inner pot;
A lid that is attached to the main body so as to be opened and closed, and seals the inner pot;
Heating means for heating the inner pot;
An exhaust port for discharging the steam in the inner pot provided in the lid,
Pressure detecting means for detecting the pressure in the inner pot;
A blocking valve that closes the exhaust port, a pressing portion that applies a pressing force to the blocking valve via a spring having a predetermined elastic force, and is movable between a blocking position and an opening position; A pressure adjusting device having a pressing portion moving means for moving in the closing direction toward the closing position or in the opening direction toward the opening position, and a stepping motor capable of rotating forward and backward to drive the pressing portion moving means;
At the time of pressure rice cooking, based on the signal from the pressure detection means, by rotating the stepping motor of the pressure adjusting device in the normal rotation direction or the reverse direction and moving the pressing portion in the closing direction or the opening direction, Control means for pressurizing or depressurizing the pressure in the inner pot,
When the pressure in the inner pot is reduced, the control means rotates the stepping motor in the reverse direction for a predetermined on time, and then turns off the stepping motor for a predetermined off time. Characterized pressure cooker.   The pressure cooker according to claim 1, wherein the on-time and the off-time are set according to the pressure in the inner pot.   The pressure cooker according to claim 1 or 2, wherein the on-time and the off-time are individually set according to each rice cooking menu, each process, or rice cooking capacity. Inner pot,
A main body for accommodating the inner pot;
A lid that is attached to the main body so as to be opened and closed, and seals the inner pot;
Heating means for heating the inner pot;
An exhaust port for discharging the steam in the inner pot provided in the lid,
Pressure detecting means for detecting the pressure in the inner pot;
A blocking valve that closes the exhaust port, a pressing portion that applies a pressing force to the blocking valve via a spring having a predetermined elastic force, and is movable between a blocking position and an opening position; A pressure adjusting device having a pressing portion moving means for moving in the closing direction toward the closing position or in the opening direction toward the opening position, and a stepping motor capable of rotating forward and backward to drive the pressing portion moving means;
At the time of pressure rice cooking, based on the signal from the pressure detection means, by rotating the stepping motor of the pressure adjusting device in the normal rotation direction or the reverse direction and moving the pressing portion in the closing direction or the opening direction, Control means for pressurizing or depressurizing the pressure in the inner pot,
A clock pulse output circuit that outputs a clock pulse having a predetermined frequency to the control means, and when the pressing portion is moved to the open position, the pressing portion moving means is turned on to come into contact, and the control means Provide a micro switch that outputs a signal to
The control means counts the clock pulse that is output while the stepping motor is rotated in the forward direction or the reverse direction from the time when the microswitch is turned on. A pressure rice cooker that adds the counted number of clock pulses when rotated in the direction of rotation, and subtracts the counted number of clock pulses when rotated in the direction of rotation of the stepping motor.   When the micro switch is turned on, the control means sets the motor position of the stepping motor to a zero point, and drives the stepping motor to rotate in the forward rotation direction so that the counted value is a positive first predetermined number. The pressure rice cooker according to claim 4, wherein the motor position of the stepping motor when it becomes is set as a MAX point.   The said control means turns off the said stepping motor, when the said count value becomes 0 corresponding to the said zero point, or the said positive 1st predetermined number corresponding to the said MAX point. The pressure cooker described in 1.   6. The control unit according to claim 5, wherein the stepping motor is turned off when the count value reaches the first positive predetermined number or the second negative predetermined number corresponding to the MAX point. The described pressure cooker. Inner pot,
A main body for accommodating the inner pot;
A lid that is attached to the main body so as to be opened and closed, and seals the inner pot;
Heating means for heating the inner pot;
An exhaust port for discharging the steam in the inner pot provided in the lid,
Pressure detecting means for detecting the pressure in the inner pot;
A blocking valve that closes the exhaust port, a pressing portion that applies a pressing force to the blocking valve via a spring having a predetermined elastic force, and is movable between a blocking position and an opening position; A pressure adjusting device having a pressing portion moving means for moving in the closing direction toward the closing position or in the opening direction toward the opening position, and a stepping motor capable of rotating forward and backward to drive the pressing portion moving means;
At the time of pressure rice cooking, based on the signal from the pressure detection means, by rotating the stepping motor of the pressure adjusting device in the normal rotation direction or the reverse direction and moving the pressing portion in the closing direction or the opening direction, Control means for pressurizing or depressurizing the pressure in the inner pot,
The said control means turns off the said stepping motor for a predetermined time, when changing the rotation direction of the said stepping motor to reverse direction, The pressure rice cooker characterized by the above-mentioned. Inner pot,
A main body for accommodating the inner pot;
A lid that is attached to the main body so as to be opened and closed, and seals the inner pot;
Heating means for heating the inner pot;
An exhaust port for discharging the steam in the inner pot provided in the lid,
Pressure detecting means for detecting the pressure in the inner pot;
A blocking valve that closes the exhaust port, a pressing portion that applies a pressing force to the blocking valve via a spring having a predetermined elastic force, and is movable between a blocking position and an opening position; A pressure adjusting device having a pressing portion moving means for moving in the closing direction toward the closing position or in the opening direction toward the opening position, and a stepping motor capable of rotating forward and backward to drive the pressing portion moving means;
At the time of pressure rice cooking, based on the signal from the pressure detection means, by rotating the stepping motor of the pressure adjusting device in the normal rotation direction or the reverse direction and moving the pressing portion in the closing direction or the opening direction, Control means for pressurizing or depressurizing the pressure in the inner pot,
The pressure rice cooker characterized in that the control means slows the initial rotation speed of the stepping motor at the time of starting the rotation driving of the stepping motor or changing the rotation direction of the stepping motor to the reverse direction.

Images