JP2013152063A - Gas cooking stove - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas cooking stove which includes a pan bottom temperature sensor having a thermosensitive head incorporating a thermosensitive element 43 and has such a configuration that, upon mounting a cooking vessel on a trivet on a top plate, the thermosensitive head comes into contact with a bottom face of the cooking vessel and is pushed downward, wherein the gas cooking stove includes a detection circuit 6 having a detection switch 61 that is turned on when the thermosensitive head is pushed downward, the detection circuit is connected to a control board 5 powered by a battery 51, and while the detection switch is in an off state, the stove burner is controlled by a system different from a system working while the detection switch is in an on state; and wherein a voltage application time period from the battery to the detection circuit is decreased to elongate the battery life.SOLUTION: A gas cooking stove includes a thermal power generation element 26 that is heated by flames of a stove burner. A voltage is applied from a battery 51 to a detection circuit 6 in a predetermined period from an ignition operation of the stove burner until a predetermined electromotive voltage is generated in the thermal power generation element 26, and after the predetermined period, a voltage from the thermal power generation element 26 is applied to the detection circuit 6.

Description

  The present invention relates to a pan bottom having a thermal head with a built-in thermal element supported by an upper end of a support pipe that is vertically long and inserted into a burner inner space surrounded by an annular stove burner. The present invention relates to a gas stove that includes a temperature sensor and is configured such that when a cooking container is placed on the virtues on a top plate, a thermal head is pressed against the bottom of the cooking container.

  Conventionally, as a gas stove of this type, a detection circuit provided with a detection switch that is turned on when the thermal head is pushed down to detect whether or not a cooking container is placed on the virtues is provided. Is connected to the control board, and when the detection switch is off, the control of the control burner different from when the detection switch is on, for example, when the detection switch is off during the ignition operation of the control burner, An ignition limit control that prohibits ignition of the burner is performed, and when the detection switch is turned off after ignition, a combustion limit control that includes at least one of reducing the fire power of the stove burner and extinguishing the fire is known. (For example, refer to Patent Document 1).

  Here, a battery is generally used as the power source of the control board. Then, a voltage is applied from the battery to the detection circuit so that the voltage input from the detection circuit to the control board is switched by turning on and off the detection switch, and the on / off of the detection switch is determined by switching the input voltage. . However, if a voltage is applied from the battery to the detection circuit, the battery life is shortened by the power consumption of the detection circuit.

JP 2010-139189 A

  In view of the above, an object of the present invention is to provide a gas stove capable of shortening the voltage application time from the battery to the detection circuit and extending the battery life.

  In order to solve the above-described problems, the present invention provides a thermal element that is supported by being urged upward by an upper end portion of a vertically long support pipe that is inserted into a burner inner space surrounded by a ring-shaped stove burner. A gas stove having a pan bottom temperature sensor with a built-in thermal head, and when the cooking container is placed on the virtues on the top plate, the thermal head abuts against the bottom of the cooking container and is pushed down. In order to detect whether or not the cooking container is placed, the detection circuit is provided with a detection switch that is turned on when the thermal head is pushed down, and the detection circuit is connected to a control board powered by a battery. When the detection switch is off, the control of the conburner is different from that when the detection switch is on, and includes a thermoelectric generator that is heated by the flame of the combo burner, A voltage from the battery is applied to the detection circuit for a predetermined period from when the ignition operation of the turbo-burner to when a predetermined electromotive force is generated in the thermoelectric generation element, and after the predetermined period, a voltage is applied to the detection circuit from the thermoelectric generation element To do.

  According to the present invention, since the voltage is applied from the thermoelectric generator to the detection circuit after the predetermined period, even if the application of the power from the battery to the detection circuit is stopped, the detection board can be turned on and off at the control board. Can be discriminated. And since the power application time from the battery to the detection circuit can be shortened to the predetermined period, the battery life is extended.

Sectional drawing which shows the gas stove of embodiment of this invention. (A) Sectional drawing of the pan bottom temperature sensor provided in the stove of FIG. 1, (b) Sectional drawing of the state which pushed down the thermal head. The electric circuit diagram containing the control board provided in the stove of FIG. The flowchart which shows the control content which a control board performs.

  Referring to FIG. 1, reference numeral 1 denotes a top plate that covers the upper surface of a stove body (not shown). The top plate 1 is provided with a burner opening 1a, and the stove burner 2 is installed in the stove body so as to face the burner opening 1a. On the top plate 1, a virtu 3, which is formed by attaching a plurality of virgin claws 32 to a ring-shaped virtuosity frame 31 so as to surround the stove burner 2, cooks a pot or the like placed on the virtues 3 The container is heated with a stove 2.

  The stove burner 2 has an annular burner body 22 connected to the mixing tube 21, an annular burner cap 23 that is placed on the burner body 22 and defines a flame opening 23 a between the burner body 22, and the burner cap 23. It is comprised by the well-known annular burner provided with the cyclic | annular secondary air guide plate 24 mounted on the top and defining a secondary air path between the burner caps 23. An ignition electrode 25 and a thermocouple 26 that is a thermoelectric generator that is heated by the flame of the stove burner 2 are attached to the outer periphery of the stove burner 2.

  The gas supply path 27 to the stove burner 2 is opened by an ignition operation by a normally closed first electromagnetic valve 271 and an operation button (not shown) on the front surface of the stove main body and is closed by a fire extinguishing operation in order from the upstream side. A manual main valve 272, a manual flow rate adjustment valve 273 interlocked with a heating power adjustment lever (not shown) on the front surface of the stove body, a normally open second electromagnetic valve 274, and an orifice 275 in parallel with the second electromagnetic valve 274 Is installed. Then, when the first electromagnetic valve 271 is closed, the gas supply to the burner 2 is stopped, and when the second electromagnetic valve 274 is closed, the amount of gas supplied to the burner 2 is limited to a small amount defined by the orifice 275. As a result, the firepower of the burner 2 is weakened.

  Moreover, the pan bottom temperature sensor 4 which protrudes upwards of the stove burner 2 through the burner inner space enclosed by the stove burner 2 is installed. The pan bottom temperature sensor 4 includes a support pipe 41 that is vertically inserted in the burner inner space, and a thermal head 42 that is supported by the upper end of the support pipe 41. The support pipe 41 is fixed to the stove burner 2 with a fixture (not shown). As shown in FIG. 2, the thermal head 42 includes a heat collecting plate 42a that contacts the bottom surface of the cooking container, an inner cylinder 42b whose upper end is closed by the heat collecting plate 42a, and an outer cylinder for heat insulation that surrounds the inner cylinder 42b. 42c, and a heat sensitive element 43 such as a thermistor for detecting the temperature of the cooking container is attached to the lower surface of the heat collecting plate 42a via the heat collecting plate 42a.

The inner cylinder 42b is externally attached to a spring receiving portion 41a having an enlarged diameter formed at the upper end portion of the support pipe 41 so as to be movable up and down, and a relatively small space is provided between the spring receiving portion 41a and the heat collecting plate 42a. a first spring 44 _first spring constant is small upper, relatively spring constant is interposed the two upper and lower springs of the _two second spring 44 of the larger lower, the thermal head 42 relative to the support pipe 41 first The first and second springs 44 ₁ and 44 ₂ are biased upward. Further, a stepped portion 42d having a reduced diameter is formed at the lower end portion of the inner cylinder 42b. In a free state where the cooking container is not placed on the Gotoku 3, the thermal head 42 has a stepped portion 42d on the lower surface of the spring receiving portion 41a. The upper moving end position regulated by the contact is held. At the upper moving end position, the thermal head 42 protrudes above the virtues 3. And when a cooking container is mounted in Gotoku 3, the thermal head 42 contacts the bottom face of a cooking container so that it can be pushed down.

  The lead wire 43a extending from the heat sensitive element 43 is inserted into the support pipe 41, drawn out from the lower end thereof, and connected to the control board 5 in the stove body (see FIG. 3). When the temperature of the cooking container detected by the thermosensitive element 43 rises to a predetermined superheat temperature, the control board 5 closes the second electromagnetic valve 274 to weaken the heating power of the conoburner 2, and thereafter the temperature of the cooking container is maintained. When the temperature is not lower than the overheat temperature, the first electromagnetic valve 271 is closed to perform the overheat prevention control for extinguishing the burner 2. A heat insulation coating 43b is extrapolated on the upper portion of the lead wire 43a.

  Moreover, in order to detect whether the cooking container is mounted in Gotoku 3, the detection circuit 6 provided with the detection switch 61 which turns on when the thermal head 42 is pushed down is provided. 6 is connected to the control board 5 (see FIG. 3). When the detection switch 6 is off, the control of the combustor 2 is different from that when the detection switch 6 is on. For example, when the detection switch 61 is off during the ignition operation of the control burner 2, the control burner 2 is ignited. When the ignition restriction control to be prohibited is performed and the detection switch 61 is turned off after ignition, the control board 5 performs the combustion restriction control including at least one of weakening the fire power of the conburner 2 and extinguishing the fire. . Specific control contents will be described later.

The detection switch 61 can be configured by a microswitch or the like that is fixed at a fixed position outside the support pipe 41 and cooperates with a dog fixed to the lower end portion of the thermal head 42. A detection switch 61 is housed in the head 42. Specifically, the detection switch 61, as shown in FIG. 2, the contact member 61a composed interposed the insulating material made of the intermediate spring receiver between the first spring 44 ₁ and ₂ the second spring 44 the first spring 44 _first receives an upper end, and a conductive member 61b made of a metallic spring bearing mounted on the lower surface of the heat collecting plate 42a. A pair of contacts 61c and 61c connected to the pair of lead wires 6a and 6a for the detection circuit 6 are provided on the upper end surface of the contact member 61a.

When placing the cooking vessel on the trivet, first, a small first spring 44 ₁ of the spring constant is compressed, as shown in FIG. 2 (b), the lower end portion of the conductor member 61b is in contact with the contacts 61c, 61c, Both contacts 61c, 61c are electrically connected via the conductor member 61b, and the detection switch 61 is turned on.

  With reference to FIG. 3, the control board 5 uses a battery 51 as a power source and has a CPU 52. In addition to the thermal element 43 and the detection circuit 6, the control board 5 is connected to a point fire extinguishing switch 7 that is turned on by an ignition operation of an operation button and turned off by a fire extinguishing operation. The control board 5 includes a switching element 53 that connects the battery 51 to the detection circuit 6, and a diode 54 that connects the thermocouple 26 to a portion of the detection circuit 6 between the detection switch 61 and the switching element 53. ing.

  The control contents performed by the control board 5 are as shown in FIG. 4, and this point will be described below. First, in STEP 1, it is determined whether or not the fire extinguishing switch 7 is turned on by an ignition operation. If turned on, the process proceeds to STEP 2 where the switching element 53 is turned on, and a voltage is applied from the battery 51 to the detection circuit 6. Next, in STEP 3, it is determined whether or not the input voltage Vs from the detection circuit 6 is zero. If the input voltage Vs is zero, the detection switch 6 is turned off, that is, it is determined that the cooking container is not placed on the five virtues, and the process proceeds to STEP 4 and an error display indicating that the cooking container is not placed is displayed. Return to STEP1. In this case, the normally closed first electromagnetic valve 271 remains closed, and no gas is supplied to the stove burner 2, so that ignition restriction control for prohibiting ignition is performed.

  If it is determined in STEP 3 that the input voltage Vs is not at a low level, the process proceeds to STEP 5 where the igniter (not shown) is energized and sparked by the ignition electrode 25 for a certain period of time, and the first electromagnetic valve 271 is opened in STEP 6. Then, the stove burner 2 is ignited.

  Next, in STEP 7, it is determined whether or not a predetermined set time has elapsed since the ignition operation of the burner 2 was performed. This set time is set in accordance with the time taken from the ignition operation of the stove burner 2 to the generation of a predetermined electromotive voltage in the thermocouple 26. And when setting time passes, it progresses to STEP8 and the switching element 53 is turned off. The electromotive voltage of the thermocouple 26 may be monitored, and it may be determined in STEP 7 whether or not the electromotive voltage has increased to a predetermined voltage, and when it has increased to the predetermined voltage, the process may proceed to STEP 8. In any case, the switching element 53 is turned on and a voltage is applied from the battery 51 to the detection circuit 6 for a predetermined period from the ignition operation of the stove burner 2 until a predetermined electromotive voltage is generated in the thermocouple 26. After a predetermined period, the switching element 53 is turned off, and a voltage is applied from the thermocouple 26 to the detection circuit 6.

  Next, in STEP 9, it is determined whether or not the input voltage Vs from the detection circuit 6 has become zero. When the detection switch 61 is turned off and the input voltage Vs becomes zero, the routine proceeds to STEP 10 where the second electromagnetic valve 274 is closed, and combustion restriction control for weakening the heating power of the stove burner 2 is performed. Thereafter, the process proceeds to STEP11, where it is determined again whether or not the input voltage Vs is zero. If it is not zero, the second electromagnetic valve 274 is opened at STEP12 and then the process returns to STEP9. On the other hand, if the input voltage Vs remains zero, the process proceeds to STEP 13 to determine whether or not a predetermined time has passed with the input voltage Vs remaining zero. And when predetermined time passes, it progresses to STEP15, the 1st solenoid valve 271 is closed, and the 2nd combustion restriction control which extinguishes the burner 2 is performed. Note that as the combustion restriction control when the detection switch 61 is turned off, one of weakening the fire power of the stove burner 2 and extinguishing the fire may be performed.

  When it is determined in STEP 9 that the input voltage Vs from the detection circuit 6 is not zero, the process proceeds to STEP 14 and it is determined whether or not the input voltage Vs is equal to or greater than a predetermined threshold YV. Here, the input voltage Vs is equal to the electromotive voltage of the thermocouple 26, and when the misfire of the combustor 2 occurs, the input voltage Vs falls below the threshold YV. When Vs ≧ YV, the process returns to STEP 9; however, when Vs <YV, the process proceeds to STEP 15 and the first electromagnetic valve 271 is closed to perform misfire safety control for preventing the release of raw gas. .

  Further, although not shown in FIG. 4, the control board 5 performs the above-described overheating prevention control when the temperature of the cooking container detected by the heat sensitive element 43 rises to the overheating temperature, and the point fire extinguishing switch 7 by the fire extinguishing operation. When is turned off, the first electromagnetic valve 271 is closed.

  According to the present embodiment, the voltage from the battery 51 is applied to the detection circuit 6 only for a predetermined period from the ignition operation of the stove burner 2 until a predetermined electromotive voltage is generated in the thermocouple 26. It is possible to shorten the voltage application time from the battery 51 to extend the battery life. In addition, after the predetermined period, since voltage is applied from the thermocouple 26 to the detection circuit 6, the detection switch 6 can be turned on / off by the control board 5 even when the power application from the battery 51 to the detection circuit 6 is stopped. Can be determined without problems.

  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 embodiment, the thermocouple 26 is connected to the detection circuit 6 via the diode 54. However, the detection circuit 6 is provided with a changeover switch for selectively connecting the battery 51 and the thermocouple 26 to the predetermined circuit. After the period, the changeover switch may be switched from the battery side to the thermocouple side, and a voltage may be applied to the detection circuit 6 from the thermocouple 26. Moreover, in the said embodiment, although the thermocouple 26 is used as a thermoelectric power generation element which generate | occur | produces the electromotive force by being heated with the flame of the stove burner 2, a thermoelectric power generation element is not limited to the thermocouple 26. Further, an automatic type is used as the flow rate adjusting valve 273, and the heating power of the cooker 2 is automatically adjusted by the flow rate adjusting valve 273 so that the temperature of the cooking container detected by the thermal element 43 is maintained at the set temperature. Is also possible.

  DESCRIPTION OF SYMBOLS 1 ... Top plate, 2 ... Combustor, 26 ... Thermocouple (thermoelectric power generation element), 3 ... Gotoku, 4 ... Pan temperature sensor, 41 ... Support pipe, 42 ... Thermal head, 43 ... Thermal element, 5 ... Control board, 51 ... Battery, 6 ... Detection circuit, 61 ... Detection switch.

Claims (1)

A pan bottom temperature sensor having a thermal head with a built-in thermal element, supported upwardly by an upper end portion of a support pipe that is vertically inserted in a burner inner space surrounded by a ring-shaped stove burner. , A gas stove in which when the cooking container is placed on the virtues on the top plate, the thermal head is pressed against the bottom surface of the cooking container,
In order to detect whether or not the cooking container is placed in the five virtues, the detection circuit is provided with a detection switch that is turned on when the thermal head is pushed down, and the detection circuit is provided on a control board that uses a battery as a power source. When connected and when the detection switch is off, the control of the control burner is different from when the detection switch is on.
It has a thermoelectric generator that is heated by the flame of the burner, and a voltage is applied from the battery to the detection circuit for a predetermined period from the ignition operation of the burner to the occurrence of a predetermined electromotive voltage at the thermoelectric generator. A gas stove characterized by applying a voltage from a thermoelectric generator to a detection circuit.

Images