JP2010014335A - Gas cooking stove - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a gas cooking stove capable of promptly detecting valve opening failure when the so-called valve opening failure that a solenoid safety valve is kept in an opened state, and not closed, occurs in a case when a valve of a fire power adjustment section is not closed. <P>SOLUTION: When a flame detecting sensor 15 disposed on a gas burner which is not ignited, detects flame, in a state that all of ignition plugs 16 are operated, a main valve 3 is closed, and a mode is transferred to a predetermined prescribed abnormality generation mode, thus the valve opening failure of the solenoid safety valve and the like can be instantaneously detected. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a gas stove provided with a plurality of gas burners.

  The gas stove is provided with a plurality of gas burners on the upper surface, and in the case where a grill cabinet that can be taken in and out from the front is provided, a gas burner for grill is attached in the grill cabinet. In such a gas stove, gas is supplied to each burner from a gas supply source via a main valve. Since it is necessary to individually supply gas to each gas burner, gas branch pipes that supply gas to each burner downstream of the main valve are connected in parallel to each other. And the thermal power control unit for adjusting the thermal power by opening and closing the gas branch pipe to each gas burner and increasing / decreasing the amount of gas to supply is provided in each gas branch pipe (for example, refer patent document 1). .

This thermal power control unit has a built-in thermal power control unit whose degree of opening and decrease is controlled by a motor, and the thermal power is adjusted between high and low heat by controlling the increase and decrease of the amount of gas passing through this thermal power control unit. The In addition, an electromagnetic safety valve for opening and closing the gas branch pipe in order to extinguish the gas burner is connected in series to the heating power control unit. This electromagnetic safety valve is held open by electric power supplied from the outside.
Japanese Patent Laying-Open No. 2006-189231 (FIG. 2)

  When a gas burner is not used for the thermal power control unit of the thermal power control unit attached to each of the gas burners, an electromagnetic safety valve for stopping the supply of gas to the gas burner is connected in series to the thermal power control unit. However, when a so-called valve opening failure occurs in which the electromagnetic safety valve remains open, the gas branch pipe to which the thermal power control unit in which the valve opening failure has occurred is not closed. . In this state, when an ignition operation is performed on another gas burner, the main valve is opened by the ignition operation. Gas will be supplied.

  Thus, when the electromagnetic safety valve fails to open, it is a relatively serious failure among the multiple types of failures that occur in the gas stove. Therefore, the occurrence of the valve opening failure is quickly detected and appropriate measures such as repair are taken. There is a need.

  In view of the above problems, an object of the present invention is to provide a gas stove that can quickly detect a valve opening failure when a valve opening failure occurs in an electromagnetic safety valve.

  In order to solve the above problems, a gas stove according to the present invention includes a plurality of gas burners connected to a gas supply source through one electromagnetic open / close type main valve, and gas in parallel with each other for supplying gas to each gas burner. A gas stove having a thermal power control unit interposed in each branch pipe, the thermal power control unit connected to the thermal power control unit whose opening degree is increased or decreased by a motor, and connected in series to the thermal power control unit. And an electromagnetic safety valve that is held open by the electric power supplied from each, and each burner is provided with a flame detection sensor for detecting ignition and an ignition plug for igniting the gas burner. When any one of the gas burners is ignited, the solenoid of the thermal power control unit attached to the gas burner is opened with the main valve opened. All the valves are opened, a predetermined amount of gas is allowed to flow through the gas burner, and all ignition plugs are operated to ignite the gas burner, and a gas burner other than the gas burner that is not ignited When the flame detection sensor arranged in the above detects a flame, the main valve is closed to shift to a predetermined abnormality occurrence mode set in advance.

  In addition, in order to prevent unburned raw gas from being released from the gas burner before detecting the occurrence of the valve opening failure, the original valve is closed when ignition operation is not performed on all the gas burners. It is desirable that

  By the way, since it is desired to detect the ignition in a short time, when a thermocouple is used as the flame detection means, the rate of increase in the detected temperature within a predetermined time from the ignition operation is predetermined. It is desirable to determine that the ignition has occurred when it is faster than the rising speed. However, if dirt or the like adheres to the surface of the protective tube that covers the thermocouple, the rate of temperature rise is slow, and there is a risk that it may be determined that the ignition is not ignited despite ignition. Therefore, in order to detect ignition even when ignition cannot be detected at a temperature increase rate, it is determined that the ignition has occurred when the detected temperature increase rate within a predetermined time from the ignition operation is faster than the predetermined increase rate. In addition to the first ignition determination means, the detected temperature exceeds the predetermined temperature when the second predetermined time elapses longer than the predetermined time even when the first ignition means does not determine ignition. It is desirable to provide a second ignition determination means for determining that the ignition has occurred.

  As is apparent from the above description, the present invention can quickly detect the occurrence of a valve opening failure even when a valve opening failure occurs in the electromagnetic safety valve.

  With reference to FIG. 1, 1 is an example of a gas stove according to the present invention. The gas stove 1 is provided with two large burners 11 and a middle burner 12 on the upper surface, and a gas burner for grilling (a pair of an upper fire burner and a lower fire burner) in a grill cabinet 13 that can be taken in and out from the front. Is provided. In addition to the power switch 10, dials 11a, 12a, and 13a are provided on the front side for point fire extinguishing and heating power adjustment of each burner. For example, when the middle burner 12 is ignited, the middle burner 12 is ignited by pressing the dial 12a to perform the ignition operation. Then, the heating power is adjusted by turning the dial 12a left and right, and the middle burner 12 is extinguished by pressing the dial 12a again.

  As shown in FIG. 2, each of the burners is connected to a large burner 11, an intermediate burner 12, and branch pipes 31 that branch the gas to both burners of the grill 13 through a main valve 3 that is an electromagnetic on-off valve. It is provided in parallel. Each branch pipe 31 is provided with a thermal power adjustment unit 2.

  The thermal power control unit 2 includes a thermal power control unit 4 that adjusts the opening degree by a motor driven by a signal from the controller 4, and an electromagnetic safety valve 5 provided in series upstream of the thermal power control unit 4. ing. The electromagnetic safety valve 5 is opened by a heating power adjusting motor, but is kept open by the electric power supplied from the controller 6 during ignition of the gas burner.

  Each burner is provided with a thermocouple 15 that is a flame sensor for detecting ignition in an ignition state. The output signals from these thermocouples 15 are individually input to the controller 6.

  Each burner is provided with a spark plug 16 as an ignition means. The operation of each of these spark plugs 16 is controlled by the controller 6, but even when any one of the burners is ignited, all the spark plugs 16 are operated to generate a spark discharge with each burner. Has been.

  Referring to FIGS. 3 and 4, each heating power adjustment unit 2 is provided with one stepping motor 21, and a cam 22 and a rotating plate 41 built in the stepping motor 21 are configured to rotate. ing. When the cam 22 rotates, the rod 23 is pushed to forcibly open the electromagnetic safety valve 5. When it is confirmed by the controller 6 that the gas burner has been ignited, the electromagnetic safety valve 5 is kept open by the controller 6 even after the cam 22 rotates and the rod 23 is retracted.

  The rotation plate 41 is provided with one passage hole 42, and the gas flows through the passage hole 44 that coincides with the passage hole 42 among the plurality of passage holes 44 provided in the fixed plate 43. Has been. An orifice plate 45 is attached to the upper surface of the fixed plate 43, that is, on the downstream side, and a gas whose flow rate is regulated by the orifice holes 46 provided corresponding to the passage holes 44 flows to the gas burner. . Therefore, when the gas type is changed and the gas flow rate must be changed even with the same thermal power, the orifice plate 45 may be replaced. Since the rotating plate 41 is rotated by the stepping motor 21 as described above, an ignition operation is performed, and the heating power is suitable for ignition in a state where the electromagnetic safety valve 5 is forcibly opened by the rod 23 as described above. For example, it is configured to be a medium fire. When ignition is confirmed by the thermocouple 15, the stepping motor 21 further rotates forward to retract the rod 23. During the ignition, the cam 22 moves the rod 23 again to the electromagnetic safety valve 5 side even if the stepping motor 21 is reversed. A play (hysteresis) is provided between the cam 22 and the rotating shaft of the stepping motor 21 so as not to be pushed.

  In the above configuration, when the power switch 10 is turned on, the controller 6 enters the standby mode, but in this state, the main valve 3 is in a closed state. In this state, for example, when the dial 12a is pushed and the middle burner 12 is ignited, the controller 6 operates the stepping motor 21 of the thermal power adjustment unit provided for the middle burner 12, The electromagnetic safety valve 5 of the thermal power control unit 2 is opened and the main valve 3 is opened. Then, a gas having a flow rate corresponding to the medium fire is supplied to the middle burner 12. Then, the spark plug 16 is actuated by the controller 6 and spark discharge is generated between the spark plug 16 and the middle burner 12, so that the middle burner 12 is ignited. When the thermocouple 15 detects this ignition, the controller 6 retracts the rod 23 and the heating power can be adjusted.

  Here, for example, when the electromagnetic safety valve 5 of the thermal power control unit 2 provided for the large burner 11 is left open due to a foreign object or the like, that is, when the valve opening failure occurs, the large burner 11 is provided. In the thermal power control unit 2, the gas reaches the thermal power control unit 4 through the electromagnetic safety valve 5.

  In the present embodiment, the thermal power control unit 4 prepares for the next ignition in the fire extinguishing state, and the passage hole 42 of the rotating plate is formed in one or more passage holes 44 of the fixed plate 43 in order to flow an amount of gas that can be reliably ignited. Configured to match. Therefore, the gas is supplied to the large burner 11 through the thermal power control unit 4. As described above, since the spark plug 16 operates simultaneously, the large burner 11 that has not been ignited is also ignited in addition to the middle burner 12 that has been ignited.

  When the other burner which has not been ignited in this way, in this case, the large burner 11 is ignited, the thermocouple 15 provided in the large burner 11 detects the ignition and outputs a signal to the controller 6. To do. When the controller 6 determines that the burner which has not been ignited has ignited, the main valve 3 is immediately closed, an error is notified, maintenance is performed, and the operation of the gas stove 1 is stopped until the valve opening failure is resolved. .

  By the way, when the electromagnetic safety valve 5 fails to open, the gas is unintentionally supplied to the gas burner. If the amount of gas supplied is small and the ignition is not ignited, the controller 6 detects the occurrence of the valve opening failure. Gas cannot be released and the gas continues to be released. Therefore, in the present embodiment, the thermal power control unit 4 of each thermal power control unit 2 has a passage hole 42 corresponding to a medium fire so that an amount of gas that can be ignited reliably flows in an initial state in preparation for the next ignition. It is set to coincide with the passage hole 44 close to it.

  By the way, the ignition to the gas burner is detected by the thermocouple 15, but if dirt is attached to the protective tube of the thermocouple 15 after many years of use, the thermoelectromotive force output from the thermocouple 15 is lowered and it is difficult to detect the ignition. Become. Therefore, it is desirable to detect ignition in a short time when the output is not reduced, and to reliably detect ignition when the output is reduced.

  Therefore, in the present invention, ignition is detected in two stages. Referring to FIG. 5, in the state where the output has not decreased, when the ignition operation is performed and the gas burner is actually ignited, the thermoelectromotive force output from thermocouple 15 rapidly increases as indicated by R1. Since the thermoelectromotive force is proportional to the detected temperature, the temperature increase rate at a predetermined time t1 after the ignition operation is performed, that is, the thermoelectromotive force increase rate is compared with the reference speed S (= V1 / t1), and the reference speed S is set. If it exceeds, it is determined that it has ignited. In this case, it can be determined at time t1 that ignition has occurred.

  On the other hand, when the output of the thermocouple 15 decreases and the rate of increase of the thermoelectromotive force falls below the reference speed S, ignition is determined based on whether or not the reference thermoelectromotive force V2 has been exceeded by the elapse of time t2. . Therefore, in the case shown in FIG. 5, it can be determined that the ignition has occurred even in the case of R2 indicating the case where the output is reduced.

  In addition, this invention is not limited to an above-described form, You may add a various change in the range which does not deviate from the summary of this invention.

The figure which shows the structure of one embodiment of this invention Block diagram showing piping status in gas stove Diagram showing the structure of the thermal power control unit Cross section mainly showing details of thermal power control unit Diagram showing changes in thermoelectromotive force

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Gas stove 2 Thermal power control unit 3 Main valve 4 Thermal power control part 5 Electromagnetic safety valve 6 Controller 10 Power switch 15 Thermocouple 16 Spark plug 21 Stepping motor 22 Cam 23 Rod

Claims (3)

  A plurality of gas burners connected to a gas supply source through one electromagnetic open / close type main valve are provided, and each has a thermal power control unit interposed in mutually parallel gas branch pipes for supplying gas to each gas burner. A gas stove, a thermal power control unit whose opening degree is increased or decreased by a motor, and an electromagnetic safety valve that is connected in series to the thermal power control unit and is held open by electric power supplied from the outside. And each of the burners is provided with a flame detection sensor for detecting ignition and a spark plug for igniting the gas burner, and any one of the gas burners is ignited. When an operation is performed, with the main valve open, the electromagnetic safety valve of the thermal power control unit attached to the gas burner is opened, and a predetermined amount of gas flows through the gas burner. At the same time, when all the spark plugs are operated to ignite the gas burner, and the flame detection sensor disposed in the gas burner other than the gas burner that is not ignited detects the flame, The gas stove is closed to shift to a predetermined abnormality occurrence mode set in advance.   The gas stove according to claim 1, wherein the main valve is closed in a state in which no ignition operation is performed on all the gas burners.   The flame detection means is a thermocouple built in a protective tube, and a first ignition determination that determines that the ignition is performed when the detected temperature rise rate within a predetermined time from the ignition operation is faster than a predetermined increase rate. Even when the means and the first ignition means do not determine ignition, it is determined that the ignition has occurred when the detected temperature exceeds the predetermined temperature at the time when the second predetermined time longer than the predetermined time elapses. The gas stove according to claim 1 or 2, further comprising second ignition determination means.

Images