JP2014145534A - Fire power control device of burner for cooking stove - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fire power control device of a burner for a cooking stove, which reduces a gas supply amount to the burner as much as possible while preventing accident fire at the time of minimum fire power, and improves user-friendliness.SOLUTION: When receiving a minimum fire power command, a fire power control device controls a flow rate adjustment valve at an opening (a third opening) of becoming a virtual minimum gas amount set larger than a gas amount as small as possible in a range where a gas supply amount to a burner does not cause fire accident, and then gradually reduces the opening of the flow rate adjustment valve from a state where the gas supply amount to the burner becomes the virtual minimum gas amount, when a detection value TC of a detector for detecting a flame temperature is equal to or more than a predetermined restriction enable threshold YTC1.

Description

  The present invention relates to a heating power control device for a stove burner provided in a gas stove.

  Conventionally, as this type of thermal power control device, an electric flow control valve provided in the gas supply path to the burner and a control means for controlling the flow control valve are provided, and a command to reduce the thermal power of the burner to the minimum thermal power It is known to reduce the opening degree of the flow control valve to the minimum opening degree when receiving (for example, see Patent Document 1).

  By the way, even if the supply gas type is the same, gas pressure, gas components, and the like may vary depending on the region. Therefore, conventionally, the minimum opening of the flow control valve is set so that the amount of gas supplied to the burner is a gas amount that is somewhat larger (for example, about 30%) as much as possible within a range in which misfire does not occur. Even if the gas pressure, gas components, etc. vary, no misfire occurs at the minimum heating power.

  However, in this case, the minimum heating power is set to be relatively large, and the amount of evaporated water increases when performing stewed cooking or heat insulation with the minimum heating power, resulting in poor usability.

Japanese Patent Laid-Open No. 2005-261666

  In view of the above, the present invention provides a stove burner thermal power control apparatus capable of improving the usability by reducing the amount of gas supplied to the burner as much as possible while preventing misfire at the minimum thermal power. That is the issue.

  In order to solve the above-mentioned problems, the present invention is a heating control device for a burner for a stove provided in a gas stove, a flow rate adjusting valve provided in a gas supply path to the burner, and a control means for controlling the flow rate adjusting valve. And a detector for detecting the flame temperature of the burner. When the control means receives a command to reduce the burner's thermal power to the minimum thermal power, first, the control gas is supplied within a range in which the amount of gas supplied to the burner does not cause misfire. Control the flow rate control valve to an opening that will be a provisional minimum gas amount set larger than the smallest possible gas amount, and then adjust the flow rate when the detection value of the detector is equal to or greater than the predetermined throttling threshold. The valve opening is gradually reduced from a state where the amount of gas supplied to the burner becomes the temporary minimum gas amount.

  Here, if the detection value (flame temperature) of the detector is equal to or higher than the throttling threshold, no misfire occurs even if the amount of gas supplied to the burner is further reduced. According to the present invention, when the detection value of the detector is equal to or greater than the squeezable threshold, the amount of gas supplied to the burner is further reduced from the temporary minimum gas amount, so that the misfire is prevented while the minimum heating power is being reduced. The amount of gas supplied can be reduced as much as possible. Therefore, it is possible to avoid a decrease in usability due to an increase in the amount of evaporated water when cooking and keeping warm with minimum heat.

  In the present invention, a flow rate control valve having a function of steplessly changing the opening degree is used, and when the detected value of the detector is equal to or greater than the throttling threshold value, the opening degree of the flow rate control valve is set to a predetermined speed. However, it is also possible to reduce the opening degree of the flow control valve stepwise from the state where the amount of gas supplied to the burner becomes the provisional minimum gas amount. And when decreasing the opening degree of the flow control valve in stages, when the detection value of the detector after the predetermined waiting time elapses after reducing the opening degree of the flow control valve by one step In addition, the opening degree of the flow control valve may be further reduced by one step. However, if the detection value of the detector falls below a predetermined lower threshold that is set to be smaller than the throttling threshold due to a gradual decrease in opening, the flame becomes unstable and misfires due to the influence of wind and other disturbances. In order to facilitate this, it is desirable to restore the opening of the flow rate control valve to the opening before it is reduced by one step.

  In addition, if the detection value of the detector falls below a predetermined misfire determination value after starting to reduce the opening of the flow control valve from the state where the amount of gas supplied to the burner becomes the provisional minimum gas amount, it is assumed that a misfire has occurred. It is desirable that the burner be re-ignited after the determination, and that the opening of the flow control valve is returned to the opening at which the amount of gas supplied to the burner becomes the temporary minimum gas amount. According to this, even if a misfire occurs due to a sudden wind or primary pressure fluctuation, cooking can be continued by re-ignition, improving usability.

Explanatory drawing which shows the structure of the thermal-power control apparatus of embodiment of this invention. Sectional drawing of the flow regulating valve used with the thermal-power control apparatus of FIG. Explanatory drawing which shows the opening degree change of the flow regulating valve of FIG. The flowchart which shows the control content at the time of minimum heat power. The flowchart which shows the control content at the time of the minimum thermal power of other embodiment.

  Referring to FIG. 1, reference numeral 1 denotes a stove burner provided in a gas stove. The burner 1 is provided with a thermocouple 2 that is a detector that detects the flame temperature, and a pan bottom temperature sensor 3 that is in contact with the bottom surface of the cooking container heated by the burner 1 and detects the temperature of the cooking container. . Further, an electromagnetic valve 5 and a flow rate adjusting valve 6 are interposed in the gas supply path 4 to the burner 1.

As shown in FIG. 2, the flow rate control valve 6 includes a rotating plate 62 connected to the output shaft 61 a of the stepping motor 61, and a fixed plate 63 facing the rotating plate 62. The fixed plate 63, as shown in FIG. 3, are formed eight holes from the first hole 64 ₁ of the minimum diameter to the eighth hole 64 ₈ with the largest diameter is arranged in the circumferential direction, the rotary plate 62 is A single communication hole 65 having a diameter equivalent to that of the _eighth hole 648 is formed by being eccentric to the same radial position as the hole arrangement circle of the fixing plate 63. As the rotating plate 62 rotates, the communication hole 65 matches any one of the first to _eighth holes 64 ₁ to 648 of the fixed plate 62 so that the fuel gas flows through this hole. I have to. Thus, the flow rate control valve 6 opening degree, from the minimum of the first opening the fuel gas flows through the first hole 64 ₁ up to the eighth opening the fuel gas flows through the eighth hole 64 ₈ Variable in 8 steps.

  The gas stove includes a controller 7 which is a control means for controlling the electromagnetic valve 5 and the flow rate adjusting valve 6. The controller 7 receives a signal from the operation member 8 for point extinguishing and heating power adjustment, a signal from the thermocouple 2, and a signal from the pan bottom temperature sensor 3.

Here, when receiving a command (minimum thermal power command) for reducing the thermal power of the burner 1 to the minimum thermal power by the operation of the operation member 8 or a signal from the pan bottom temperature sensor 3, the amount of gas supplied to the burner 1 does not cause misfire. If the flow rate control valve 6 is controlled so as to be set to a temporary minimum gas amount that is set to be about 30% larger than a gas amount that is as small as possible in the range, misfire is prevented even if the gas pressure, gas components, etc. vary. be able to. Incidentally, the opening degree of the flow rate control valve 6 that the amount of gas supplied to the burner 1 is the temporary minimum gas amount is the third opening through which fuel gas through the third hole 64 _3. However, if the opening degree of the flow control valve 6 is kept at the third opening degree, the minimum heating power is set to be relatively large, and the amount of evaporated water increases when cooking and keeping warm with the minimum heating power. Becomes worse.

  Therefore, in the present embodiment, when the minimum thermal power command is received, the minimum thermal power control shown in FIG. 4 is performed. In the minimum thermal power control, first, the opening degree of the flow control valve 6 is decreased to the third opening degree in STEP1. In addition, if the opening degree of the flow control valve 6 is suddenly decreased from a large opening degree of, for example, the seventh opening degree or more to the third opening degree, the primary air supplied to the burner 1 is not rapidly reduced by the influence of inertia. As a result, there may be a momentary excess of air and misfire. For this reason, it is desirable that the third opening is decreased over a certain amount of time.

  After decreasing to the third opening, the process proceeds to STEP 2 to determine whether or not a predetermined waiting time t1 (for example, 1 minute) has elapsed since the decrease to the third opening. When the time has elapsed, the process proceeds to STEP3, where it is determined whether or not the detected value of the flame temperature, that is, the output TC of the thermocouple 2 is equal to or greater than a predetermined squeezable threshold YTC1. If TC ≧ YTC1, there is almost no misfire due to the decrease in the opening, so the process proceeds to STEP 4 and the opening of the flow control valve 6 is decreased to the second opening.

  Next, proceeding to STEP5, it is determined whether or not a predetermined waiting time t2 (for example, 30 seconds) has elapsed since the opening of the flow control valve 6 is decreased to the second opening, and the waiting time t2 is When the time elapses, the process proceeds to STEP 6 to determine whether or not the thermocouple output TC is equal to or greater than the squeezable threshold YTC1. It should be noted that the determination based on the thermocouple output TC is performed after the waiting times t1 and t2 have elapsed at the time of the decrease to the third opening or the decrease to the second opening even if the supply gas amount decreases. This is because the thermocouple output TC does not decrease immediately. In addition, when a minimum thermal power command is received, the gas amount may be reduced from a considerably large gas amount to a temporary minimum gas amount. In this case, it takes time for the thermocouple output TC to decrease to a value corresponding to the temporary minimum gas amount. Therefore, the waiting time t1 is set longer than the waiting time t2.

  When it is determined in STEP 6 that TC ≧ YTC1, the process proceeds to STEP 7 and the opening degree of the flow control valve 6 is decreased to the minimum first opening degree. Next, proceeding to STEP 8, it is determined whether or not the thermocouple output TC is equal to or greater than a predetermined lower threshold YTC2 that is set smaller than the squeezable threshold YTC1. When TC <YTC2, the routine proceeds to STEP9, where it is determined whether or not the thermocouple output TC is equal to or less than a predetermined misfire determination value YTC3 (which is naturally smaller than YTC2). If YTC3 <TC <YTC2, the process returns to STEP 4 to return to the second opening that is the opening before the flow control valve 6 is decreased by one step.

  If it is determined in STEP 6 that TC <YTC1, it is determined in STEP 10 whether or not the thermocouple output TC is equal to or greater than the lower threshold YTC2, and if TC <YTC2, the process proceeds to STEP 11 and the thermocouple output. It is determined whether or not TC is equal to or less than a misfire determination value YTC3. If YTC3 <TC <YTC2, the process returns to STEP 1 to return to the third opening, which is the opening before the opening of the flow control valve 6 is decreased by one step.

  Further, when it is determined in STEP 9 or 11 that TC ≦ YTC3, that is, when a misfire has occurred, the burner 1 is re-ignited in STEP 12, and the opening of the flow control valve 6 is returned to STEP 3 to return to the third opening. Let

  According to the above minimum thermal power control, when the thermocouple output TC is equal to or greater than the throttleable threshold YTC1, the amount of gas supplied to the burner 1 is further reduced from the temporary minimum gas amount, and misfire is prevented at the minimum thermal power. We can weaken firepower as much as possible. Therefore, it is possible to avoid a decrease in usability due to an increase in the amount of evaporated water when cooking and keeping warm with minimum heat.

  In addition, when the thermocouple output TC falls below the lower limit threshold YTC2 due to the stepwise opening decrease, the flame becomes unstable and easily misfires due to the influence of wind and other disturbances. In this case, the flow control valve 6 Since the opening degree is restored to the opening degree before the opening degree is decreased by one step, misfire can be effectively prevented. Furthermore, even if a misfire occurs due to a sudden wind or primary pressure fluctuation, cooking can be continued by re-ignition, improving usability.

  As described above, the embodiment in which the opening degree of the flow rate control valve 6 is decreased stepwise from the state in which the amount of gas supplied to the burner 1 becomes the temporary minimum gas amount has been described. A valve that can change the opening steplessly may be used, and when the minimum thermal power command is received, the minimum thermal power control shown in FIG. 5 may be performed.

  In this minimum thermal power control, first, in STEP 101, the opening degree of the flow control valve 6 is reduced to a temporary minimum opening degree (corresponding to the third opening degree in the above embodiment) in which the amount of gas supplied to the burner 1 becomes the temporary minimum gas amount. Let Next, the process proceeds to STEP 102, where it is determined whether or not a predetermined waiting time t1 (for example, 1 minute) has elapsed since the temporary minimum opening is decreased, and when the waiting time t1 has elapsed, the process proceeds to STEP 103. The flow control valve 6 starts to decrease from the provisional minimum opening at a predetermined speed, and at STEP 104, it is determined whether or not the thermocouple output TC is equal to or greater than the throttleable threshold YTC1.

  Then, while TC ≧ YTC1, the process returns to STEP 103 to continue the decrease in the opening degree of the flow rate control valve 6, and when TC <YTC1, the process proceeds to STEP 105, and the decrease in the opening degree of the flow rate control valve 6 is stopped. .

  Next, proceeding to STEP 106, it is determined whether or not the thermocouple output TC has become equal to or less than the misfire determination value YTC3. When TC ≦ YTC3, that is, when a misfire has occurred, the burner 1 is re-ignited in STEP 107, and the flow returns to STEP 101 to return the opening of the flow control valve 6 to the temporary minimum opening.

  As mentioned above, although embodiment of this invention was described with reference to drawings, this invention is not limited to this. For example, in the above-described embodiment, the detector that detects the flame temperature is configured by the thermocouple 2, but the detector may be configured by a sensor other than the thermocouple such as a thermistor.

  DESCRIPTION OF SYMBOLS 1 ... Burner, 2 ... Thermocouple (detector), 4 ... Gas supply path, 6 ... Flow control valve, 7 ... Controller (control means).

Claims (3)

A heating power control device for a stove burner provided in a gas stove,
A flow rate control valve interposed in the gas supply path to the burner, a control means for controlling the flow rate control valve, and a detector for detecting the flame temperature of the burner,
When the control means receives a command to reduce the burner's heating power to the minimum heating power, first, the provisional minimum is set such that the amount of gas supplied to the burner is set larger than the smallest possible gas amount within a range in which misfire does not occur. When the flow rate control valve is controlled to the opening that makes the gas amount, and then the detected value of the detector is equal to or greater than the predetermined throttling threshold, the opening amount of the flow rate control valve is set to the provisional minimum gas amount to the burner. A stove burner thermal power control device characterized by gradually decreasing the amount from the state.   Decrease the opening of the flow control valve step by step from the state where the amount of gas supplied to the burner reaches the temporary minimum gas amount, and after a predetermined waiting time has elapsed after reducing the opening of the flow control valve by one step When the detected value of the detector is equal to or greater than the throttling threshold, the flow rate control valve opening is further decreased by one step, and the detected value falls below a predetermined lower threshold that is set smaller than the throttling threshold. 2. The heating power control device for a stove burner according to claim 1, wherein the opening degree of the flow rate control valve is returned to the opening degree before being reduced by one step.   When the detected value of the detector falls below a predetermined misfire determination value after the opening of the flow control valve starts to decrease from the state where the amount of gas supplied to the burner becomes the provisional minimum gas amount, the burner is restarted. The stove burner thermal power control device according to claim 1 or 2, wherein ignition is performed and the opening of the flow control valve is returned to an opening at which the amount of gas supplied to the burner becomes a temporary minimum gas amount.

Images