Gas stoves

Abstract

The present invention provides a gas stove equipped with an electric fire control valve and a cooking vessel detection mechanism for detecting the presence of a cooking vessel on a fire support. Using only the electric fire control valve, the stove can prevent the release of raw gas when the absence of a cooking vessel is detected during an ignition operation, and can also ignite responsively when the presence of a cooking vessel is detected during an ignition operation. The electric fire control valve is biased toward opening by a biasing mechanism and switched to a fully closed state by a direct-acting component driven by an electric motor via a linkage mechanism, overcoming the biasing mechanism. If the absence of a cooking vessel is detected during an ignition operation, the electric fire control valve is switched to a fully closed state. When a flameout operation is performed, the electric fire control valve is switched to a standby state near or fully closed until the next ignition operation.

Description

Technical Field

[0001] An embodiment of the invention relates to a gas stove as described below, which includes: a stove burner facing a burner opening provided in an opening of a top plate, a fire support provided on the top plate so as to surround the burner opening, a manual operating component for igniting and extinguishing the stove burner, a fire intensity regulating valve for regulating the fire intensity of the stove burner, and a cooking container detection mechanism for detecting the presence or absence of a cooking container on the fire support. Background Art

[0002] As is well known, in the past, such gas stoves, according to Patent Document 1, when the operating member performs the ignition operation, if the cooking vessel detection mechanism detects the absence of a cooking vessel, the spark discharge from the ignition electrode is terminated, preventing the stove burner from igniting and stopping the supply of gas to the stove burner to prevent the release of raw gas (raw gas). In the gas stove described in Patent Document 1, the flame control valve comprises a latching solenoid valve, which is positioned in parallel with a throttle that regulates the minimum flame intensity of the stove burner in the gas supply path to the stove burner. Therefore, even if the flame control valve is closed, the gas supply to the stove burner cannot be stopped.

[0003] Therefore, the gas stove described in Patent Document 1 is equipped with a shutoff valve in addition to the flame control valve, which is used to stop the gas supply to the stove burner. Furthermore, when the operating member is ignited, if the cooking vessel detection mechanism detects the absence of a cooking vessel, the shutoff valve closes, thereby stopping the gas supply to the stove burner. However, the gas stove described in Patent Document 1 requires a shutoff valve in addition to the flame control valve, which disadvantageously increases costs.

[0004] Electric fire control valves driven by electric motors are also known. Furthermore, it is well known that electric fire control valves can be easily switched to a fully closed state, which stops the gas supply to the stove burner. Therefore, it is also conceivable to use an electric fire control valve that can be easily switched to a fully closed state. When the operating member performs an ignition operation, if the cooking vessel detection mechanism detects the absence of a cooking vessel, the electric fire control valve is switched to a fully closed state, thereby stopping the gas supply to the stove burner. This eliminates the need for the aforementioned shut-off valve, thereby reducing costs.

[0005] However, when using an electric fire control valve, it is necessary to switch the electric fire control valve to a suitable fire intensity for ignition, such as a maximum fire intensity, when performing an ignition operation. Therefore, it is well known that in the past, when the flame is turned off by the operating member, the electric fire control valve is switched to the maximum fire intensity state and then placed on standby until the next ignition operation. When the ignition operation is performed, the stove burner can be ignited immediately (for example, see Patent Document 2).

[0006] However, if the electric fire control valve is at maximum flame intensity until the next ignition operation, then when the ignition operation is performed and the cooking vessel detection mechanism detects the absence of a cooking vessel, it will take time for the electric fire control valve to switch to a fully closed state, during which time the raw gas will be released. In this case, providing a shutoff valve as described in Patent Document 1 in addition to the electric fire control valve can prevent the release of the raw gas, but this will result in increased costs.

[0007] Patent Literature

[0008] Patent Document 1: Japanese Patent Application Laid-Open No. 2010-139189

[0009] Patent Document 2: Japanese Patent Application Laid-Open No. 2015-169378 Summary of the Invention

[0010] The present invention has been made in view of the above-mentioned problems, and its object is to provide a gas stove as follows: in which, without providing a shut-off valve, the release of raw gas can be prevented when the absence of a cooking vessel is detected during the ignition operation, and ignition can be performed with good responsiveness when the presence of a cooking vessel is detected during the ignition operation.

[0011] In order to solve the above-mentioned problems, the gas stove of the present invention comprises: a stove burner facing the burner opening provided in the top plate opening; a fire support provided on the top plate in a manner surrounding the burner opening; a manual operating component for igniting and extinguishing the stove burner; a fire regulating valve for regulating the fire intensity of the stove burner; and a cooking container detection mechanism for detecting the presence or absence of a cooking container on the fire support, wherein when the ignition operation is performed by the operating component, if the cooking container detection mechanism detects that there is no cooking container, the supply of gas to the stove burner is stopped, and the electric fire regulating valve is constructed to be able to freely switch to a fully closed state that stops the supply of gas to the stove burner, and to be moved to an open direction by a force applying mechanism. The electric fire regulating valve is switched to a fully closed state when the operating component performs an ignition operation and overcomes the force of the force-applying mechanism through a direct-acting component, and is switched to a fully closed state. The direct-acting component is driven by an electric motor with the aid of a linkage mechanism. When the operating component performs an ignition operation, if the cooking container detection mechanism detects the presence of a cooking container, the electric fire regulating valve is switched to a state in which the fire of the stove burner is in a state suitable for ignition. If the cooking container detection mechanism detects the absence of a cooking container, the electric fire regulating valve is switched to a fully closed state, thereby stopping the supply of gas to the stove burner. When the operating component performs a flameout operation, the electric fire regulating valve is switched to a specified standby state and stands by until the next ignition operation. The standby state is set to a fully closed state or a state close to the fully closed state.

[0012] According to the present invention, the electric fire control valve is in a standby state at or near full-closed status until the ignition operation is performed. Therefore, if the absence of a cooking vessel is detected during the ignition operation, the electric fire control valve can be immediately fully closed. Therefore, without requiring a shutoff valve, the release of raw gas can be prevented when the absence of a cooking vessel is detected during the ignition operation, thereby reducing costs. Furthermore, since the electric fire control valve is biased toward opening by a biasing mechanism, there is virtually no load when the electric fire control valve is actuated toward opening, allowing the electric motor to rotate at high speed. Therefore, if the presence of a cooking vessel is detected during the ignition operation, the electric fire control valve can be quickly switched from a standby state (at or near full-closed status) to a state with a fire intensity suitable for ignition by the high-speed rotation of the electric motor, thereby enabling responsive ignition of the stove burner.

[0013] Furthermore, when the electric fire control valve is in the fully closed standby state, the valve closing reaction force acting on the linkage mechanism via the direct-acting component may cause the linkage mechanism to bite. To prevent this bite, the standby state is preferably set to a minimum fire state near the fully closed state and with the stove burner fire at the minimum fire level. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a perspective view of a gas stove according to an embodiment of the present invention.

[0015] Figure 2 This is a circuit diagram showing gas piping of a gas stove according to an embodiment.

[0016] Figure 3 This is a cross-sectional side view of a stove burner valve unit provided in the gas stove according to the embodiment.

[0017] Figure 4 This is a cross-sectional side view of the main parts showing the operation of the electromagnetic safety valve and the operating members of the main valve provided in the valve unit for the stove burner.

[0018] Figure 5 This is an explanatory diagram showing the operation of a micro switch for detecting the position of an operating member provided in a valve unit for a stove burner.

[0019] Figure 6 This is an enlarged, cutaway side view of an electric fire control valve installed in a valve unit for a stove burner.

[0020] Figure 7 This is an explanatory diagram schematically showing the operation of the cooking vessel detection mechanism provided in the gas stove according to the embodiment.

[0021] Figure 8 This is a flowchart showing the control contents of the electric fire control valve in the gas stove according to the embodiment.

[0022] Explanation of symbols

[0023] 2…top plate; 3…stove burner; 4…fire support; 73…electric fire control valve; 734…force-applying mechanism; 735…electric motor; 736…interlocking mechanism; 737…direct-acting component; 75…operating component; 9…cooking container detection mechanism. DETAILED DESCRIPTION

[0024] Figure 1The illustrated gas stove of the embodiment of the present invention includes: a pair of left and right stove burners 3, 3 facing a pair of left and right burner openings (not shown), which are openings provided in a top plate 2 covering the upper surface of a stove body 1; a pair of left and right fire supports 4, 4 placed on the top plate 2 so as to surround the left and right burner openings; and a grill 5 assembled with the stove body 1. The front panel 11 of the stove body 1 is provided with: ignition and extinguishing keys 12, 12 for the left and right stove burners; stove burner fire adjustment levers 13, 13 located above these ignition and extinguishing keys 12, 12; an ignition and extinguishing key 14 for the grill; and a pair of upper and lower fire adjustment levers 151, 152 located above the ignition and extinguishing key 14 for the upper and lower burners of the grill 5.

[0025] Reference Figure 2 The gas supply path 6 branches into a pair of stove burner gas supply paths 6a, 6a for supplying gas to the left and right stove burners 3, 3, and a grill gas supply path 6b for supplying gas to the upper burner 51 and lower burner 52 of the grill 5. A stove burner valve unit 7 is provided on each stove burner gas supply path 6a. This valve unit 7 includes an electromagnetic safety valve 71, a main valve 72, an electric flame control valve 73, and a manual flame control valve 74 linked to the flame control lever 13. A grill valve unit 8 is provided on the grill gas supply path 6b. This valve unit 8 includes an electromagnetic safety valve 81, a main valve 82, a manual upper burner flame control valve 831 linked to the upper burner flame control lever 151, and a manual lower burner flame control valve 832 linked to the lower burner flame control lever 152.

[0026] Below, refer to Figure 3 , the valve unit 7 for the stove burner is described in detail. The structures of the electromagnetic safety valve 81, main valve 82, and manual fire regulating valves 831 and 832 of the valve unit 8 for the grill are identical to the structures of the electromagnetic safety valve 71, main valve 72, and manual fire regulating valve 74 described later in the valve unit 7 for the stove burner, and therefore their description is omitted.

[0027] The stove burner valve unit 7 includes a valve housing 70 having an inlet 70a connected to the upstream portion of the stove burner gas supply line 6a and an outlet 70b connected to the downstream portion of the stove burner gas supply line 6a. Furthermore, within this valve housing 70, assembled in order from the upstream side are an electromagnetic safety valve 71, a main valve 72, an electric fire control valve 73, and a manual fire control valve 74.

[0028] The electromagnetic safety valve 71 includes a valve seat 711, which can be opened from the upstream side, that is, from the rear ( Figure 3 The valve body 712 is seated on the valve seat 711 (center left), the armature 713 is connected to the valve body 712 by the valve shaft 712a extending rearward, the electromagnet 714 abuts against the armature 713 when the valve body 712 moves to the predetermined valve opening position away from the valve seat 711, and the valve body 712 is moved to the valve closing position ( Figure 3 The main valve 72 comprises a valve seat 721, a valve body 722 which can be seated on the valve seat 721 from behind and is fixed to an operating rod 76 described later, and a valve spring 715 which biases the valve body 722 toward the closed position ( Figure 3 The valve spring 723 is applied with force (in the position shown).

[0029] In addition, the valve unit 7 includes a manual operating member 75 supported by a guide block 751 so as to be slidable in the front-back direction, and the guide block 751 is attached to the front end of the valve housing 70. The operating member 75 is urged forward by a spring 752 and abuts against the back of the ignition off key 12. Figure 3 The operating member 75 is moved to a predetermined combustion position between the flameout position and the ignition position by releasing the pressing force at the ignition position and is locked therein. The operating member 75 is returned to the flameout position by releasing the pressing force at the combustion position. The pushing mechanism 753 is composed of a heart-shaped cam groove 753a and an engaging member 753b engaging therewith.

[0030] In addition, the operating rod 76 opposite to the rear of the operating component 75 is inserted into the valve housing 70 so as to be able to move forward and backward freely in the front-to-back direction. When the operating component 75 is pressed from the flameout position, the operating component 75 presses the operating rod 76 to move rearward, and the valve body 722 of the main valve 72 fixed to the operating rod 76 will overcome the force of the valve spring 723 and leave the valve seat 721, so that the main valve 72 is opened. When the operating rod 76 moves further rearward, the operating rod 76 will abut against the valve body 712 of the electromagnetic safety valve 71, and the valve body 712 will overcome the force of the valve spring 715 and be pressed rearward. Moreover, when the operating component 75 is pressed to the ignition position, as shown Figure 4 As shown in (a), the valve body 712 is pressed to the valve opening position where the armature 713 abuts against the electromagnet 714, thereby forcing the electromagnetic safety valve 71 to open. In addition, when the pressing at the ignition position is released, the operating member 75 returns to the combustion position by the force of the valve spring 723 and the spring 752, as shown in FIG. Figure 4As shown in (b), while the main valve 72 is maintained in the open state, the rear end of the operating rod 76 is displaced forward of the valve seat 711 of the electromagnetic safety valve 71, thereby releasing the forced opening of the electromagnetic safety valve 71. Furthermore, when the pressing operation is released after the pressing operation in the combustion position, the operating member 75 is returned to the flameout position by the forces of the valve spring 723 and the spring 752, and the main valve 72 is closed.

[0031] Reference Figure 5 The guide block 751 is provided with a micro switch 77 for detecting the position of the operating member 75. The micro switch 77 has two contacts 771 and 772, the first and the second. When the operating member 75 is in the off position, Figure 5 As shown in (a), the first and second contacts 771, 772 are disconnected. When the operating member 75 is in the burning position, as shown in FIG. Figure 5 As shown in (b), the first cam portion 7541 provided on the operating member 75 is pressed so that the first contact 771 is connected. When the operating member 75 is in the ignition position, as shown in FIG. Figure 5 As shown in (c), the second cam portion 7542 provided on the operating member 75 is pressed, so that the second contact 772 is also connected in addition to the first contact 771.

[0032] The on / off signals of the first and second contacts 771 and 772 are input to a control mechanism, or controller (not shown). When the operating member 75 is pressed from the flameout position and reaches the combustion position, closing the first contact 771, the controller begins energizing the electromagnet 714 of the electromagnetic safety valve 71. When the operating member 75 reaches the ignition position and the second contact 772 closes, spark discharge occurs via the ignition electrode 31 attached to the stove burner 3, igniting the stove burner 3. After ignition, the spark discharge via the ignition electrode 31 ends when the operating member 75 is returned to the combustion position, closing the second contact 772. However, after the first contact 771 closes, the electromagnet 714 of the electromagnetic safety valve 71 continues to energize until a predetermined waiting time has elapsed, keeping the electromagnetic safety valve 71 open. During this waiting period, if the electromotive force of thermocouple 32, a flame detection element attached to stove burner 3, rises above a specified level, the controller will continue to energize electromagnet 714 until the electromotive force of thermocouple 32 drops below the specified level due to a fire in stove burner 3. By returning operating member 75 to the flameout position, first contact 771 is disconnected, stopping the flow of power to electromagnet 714. This closes not only main valve 72 but also electromagnetic safety valve 71.

[0033] The manual fire control valve 74 has the following features: Figure 3 The needle valve body 742 is inserted into the valve hole 741 at the upper part of the valve housing 70 connected to the outflow port 70b) and is connected to the outlet port 70b. The pin 743 extending upward is fixed to the front end of the needle valve body 742 protruding from the valve housing 70. In addition, the fire adjustment rod 13 is axially supported by the boss portion 701 protruding from the upper end surface of the valve housing 70 so as to swing freely in the lateral direction. In addition, the fire adjustment rod 13 is formed with a long hole-shaped cam hole 131 that is inclined in the lateral direction relative to the front-to-back direction. Moreover, a guide plate 702 is fixed to the upper end of the valve housing 70, and a long guide hole 702a in the front-to-back direction is formed on the guide plate 702, so that the pin 743 is engaged with the cam hole 131 through the guide hole 702a. As a result, the fire intensity regulating lever 13 is swung laterally, and the pin 743 moves forward and backward through the cam hole 131. That is, the needle valve body 742 moves forward and backward in the front-back direction, thereby regulating the fire intensity of the stove burner 3. In addition, when the operating member 75 is pressed to the ignition position for ignition, the fire intensity regulating lever 13 is swung in the direction of increasing the fire intensity by means of a linkage mechanism (not shown), thereby switching the manual fire intensity regulating valve 74 to: making the fire intensity of the stove burner 3 the maximum fire intensity state (maximum fire intensity state). Figure 3 status shown).

[0034] The electric fire regulating valve 73 is configured to be able to freely switch to a fully closed state that stops the supply of gas to the stove burner 3. It is urged in the opening direction by a force applying mechanism 734, and is switched to a fully closed state by overcoming the force of the force applying mechanism 734 through a direct-acting member 737. The direct-acting member 737 is driven by an electric motor 735 composed of a stepping motor or the like through a linkage mechanism 736. Figure 6 To be more specific, the electric fire regulating valve 73 comprises: a valve seat 731, a valve member 732, a valve member 733, a valve member 734, a valve member 735, a valve member 736, a valve member 737, a valve member 738, a valve member 739, a valve member 740, a valve member 741, a valve member 742, a valve member 743, a valve member 744, Figure 6 The right side of the valve seat 731 and the opening direction of the valve seat 731 ( Figure 6The main valve body 732 (shown on the left side in the figure) and the auxiliary valve body 733, which faces the main valve body 732 in the opening direction and abuts against the linear member 737. The main valve body 732 includes a needle portion 732a that can be inserted into the valve hole 731a provided in the valve seat 731, a sealing portion 732b made of elastic material that can be seated on the valve seat 731, a throttle hole 732c that allows gas to flow from the upstream side to the downstream side of the main valve body 732 even when the sealing portion 732b is seated on the valve seat 731, and an auxiliary valve seat 732d that allows the auxiliary valve body 733 to seat and opens the throttle hole 732c. To improve sealing when seated on the auxiliary valve seat 732d, a gasket 733a made of elastic material is attached to the auxiliary valve body 733, facing the auxiliary valve seat 732d.

[0035] The biasing mechanism 734 is composed of a first biasing mechanism 734a that biases the main valve body 732 in the opening direction, and a second biasing mechanism 734b that biases the auxiliary valve body 733 in the opening direction relative to the main valve body 732 with a force stronger than that of the first biasing mechanism 734a. Furthermore, a stopper mechanism 738 is provided to prevent the auxiliary valve body 733 from moving in the opening direction relative to the main valve body 732 at a fixed position. This stopper mechanism 738 is composed of a window 738a formed in the cylindrical portion 732e of the main valve body 732 surrounding the auxiliary valve body 733, and a claw 738b that protrudes from the outer circumference of the auxiliary valve body 733 and is inserted into the window 738a with some play. When the claw 738b engages the opening-direction edge of the window 738a, the auxiliary valve body 733 is prevented from moving further in the opening direction relative to the main valve body 732.

[0036] The linkage mechanism 736 is composed of a feed screw mechanism, which in turn comprises an external thread 736a connected to the output shaft 735a of the electric motor 735, and a slider 736b that is threadedly engaged with the external thread 736a and fixed to prevent rotation. The slider 736b abuts against a diaphragm 737a that provides an airtight seal around the portion where the linkage mechanism 736 is located. Furthermore, the linear motion member 737 is connected to the diaphragm 737a.

[0037] like Figure 6As shown, the electric fire control valve 73 is fully closed when the sealing portion 732b of the main valve body 732 is seated on the valve seat 731 and the auxiliary valve body 733 is seated on the auxiliary valve seat 732d of the main valve body 732, thereby sealing the orifice 732c. This stops the gas supply to the stove burner 3. From this fully closed state, when the direct-acting member 737 is moved toward the opening direction by the electric motor 735 via the linkage mechanism 736, the auxiliary valve body 733, under the force of the second biasing mechanism 734b, follows the direct-acting member 737 and moves toward the opening direction. The main valve body 732 is prevented from continuing to move toward the opening direction by the force of the second biasing mechanism 734b until the auxiliary valve body 733 is stopped from moving toward the opening direction relative to the main valve body 732 by the stopper mechanism 738. Therefore, the sealing portion 732b of the main valve body 732 is maintained in the state seated on the valve seat 731, and the sub-valve body 733 separates from the sub-valve seat 732d, opening the orifice 732c. As a result, the electric fire-intensity regulating valve 73 is in the minimum fire-intensity state, which is the minimum fire-intensity specified by the orifice 732c. After the sub-valve body 733 is stopped from moving in the opening direction relative to the main valve body 732 by the stopper mechanism 738, if the sub-valve body 733 is further moved in the opening direction, the main valve body 732 follows the sub-valve body 733 due to the force of the first biasing mechanism 734a and moves in the opening direction. The sealing portion 732b of the main valve body 732 separates from the valve seat 731, and the fire-intensity of the stove burner 3 gradually increases.

[0038] The stove burner 3 is provided with a pot bottom temperature sensor 33 that contacts the bottom surface of the cooking container on the fire support 4. When the temperature adjustment mode is selected for cooking, the controller performs temperature adjustment control, adjusting the fire intensity of the stove burner 3 between minimum and maximum intensity via the electric fire intensity adjustment valve 73 so that the temperature detected by the pot bottom temperature sensor 33 reaches a predetermined set temperature.

[0039] In addition, the gas stove of this embodiment is equipped with a cooking vessel detection mechanism 9 for detecting the presence of a cooking vessel on the fire support 4. Specifically, the cooking vessel detection mechanism 9 is formed by using a pot bottom temperature sensor 33. Here, the pot bottom temperature sensor 33 is supported so as to be able to be raised and lowered freely. Figure 7 As shown, a micro switch 91 is provided which cooperates with a pressure plate 92, and the pressure plate 92 is installed in a component which rises and falls together with the pot bottom temperature sensor 33. The micro switch 91 and the pressure plate 92 constitute a cooking vessel detection mechanism 9. When there is no cooking vessel on the fire support 4, as shown in FIG. Figure 7As shown in (a), the pot bottom temperature sensor 33 rises, the micro switch 91 is disconnected, and when there is a cooking container P on the fire support 4, as shown in Figure 7 As shown in (b), the pot bottom temperature sensor 33 is lowered, and the micro switch 91 is pressed on the pressure plate 92 and is turned on.

[0040] Here, in order to ensure safety, it is necessary to prevent the stove burner 3 from being ignited when there is no cooking vessel on the fire support 4. Therefore, when the ignition operation is performed by the operating member 75, if the cooking vessel detection mechanism 9 detects that there is no cooking vessel, the spark discharge by the ignition electrode 31 is stopped, and the electric fire control valve 73 is switched to a fully closed state to prevent the raw gas from being released from the stove burner 3. Figure 8 , which explains the contents of the controller controlling the electric fire regulating valve 73.

[0041] According to the control of the electric fire-intensity control valve 73, first, in STEP 1, it is determined whether the operating member 75 has been used for ignition. Specifically, it is determined whether the operating member 75 has been pressed into the ignition position, thereby connecting the first and second contacts 771 and 772 of the microswitch 77. If the ignition operation is performed by the operating member 75, the process proceeds to STEP 2, where the presence of a cooking vessel on the fire support 4 is detected by turning the microswitch 91 on and off. If the microswitch 91 is on, detecting the presence of a cooking vessel, the process proceeds to STEP 3, where the electric fire-intensity control valve 73 is switched to a state suitable for ignition (ignition state), for example, to a state of maximum intensity.

[0042] Next, the process proceeds to STEP 4, where it is determined whether the operating member 75 has returned to the burning position. Specifically, it is determined whether the first contact 771 of the microswitch 77 is closed and the second contact 772 is open. If the operating member 75 has returned to the burning position, the process proceeds to STEP 5, where normal control of the electric fire control valve 73 is performed. This normal control is performed by controlling the electric fire control valve 73 based on the temperature detected by the pot bottom temperature sensor 33 when the temperature adjustment mode is selected. If the temperature adjustment mode is not selected, the electric fire control valve 73 is kept at its maximum fire level, allowing the manual fire control valve 74 to adjust the fire level.

[0043] Next, the process proceeds to STEP 6, where it is determined whether the operating member 75 has been turned off. Specifically, it is determined whether the operating member 75 has been returned to the off position, disconnecting the first and second contacts 771 and 772 of the microswitch 77. Until the off operation is performed, the process returns to STEP 5, where normal control of the electric fire control valve 73 continues. Furthermore, if the operating member 75 has been turned off, the process returns to STEP 7, switching the electric fire control valve 73 to a predetermined standby state. The process then returns to STEP 1, where the electric fire control valve 73 remains in the standby state until the next ignition operation.

[0044] Here, the standby state is a fully closed state or a state near the fully closed state. It is preferably set to a minimum fire state near the fully closed state, where the fire intensity of the stove burner 3 is at its lowest. The reason for this is as follows. Specifically, when the electric fire intensity control valve 73 is set to the fully closed state, the valve closing reaction force acting on the linkage mechanism 736 via the direct-acting component 737 may cause the linkage mechanism 736 to bite (the external thread 736a bites into the slider 736b) in the fully closed state, thereby preventing the electric fire intensity control valve 73 from quickly switching to the ignition fire intensity state during the ignition operation. In contrast, setting the electric fire intensity control valve 73 to the minimum fire intensity state prevents the aforementioned undesirable situation, which is advantageous in this respect.

[0045] If, in STEP 2, the microswitch 91 remains in the off position and the absence of a cooking vessel is detected, the process proceeds to STEP 8, where the electric fire control valve 73 is switched to the fully closed state. Furthermore, in STEP 9, an error display is displayed to inform that the absence of a cooking vessel is detected. Thus, if the electric fire control valve 73 is switched to the fully closed state, gas will not be supplied to the stove burner 3 even if the electromagnetic safety valve 71 and main valve 72 are opened during the ignition operation. Next, in STEP 10, it is determined whether the ignition operation by the operating member 75 has ended. Specifically, it is determined whether the operating member 75 has been released from the ignition position and returned to the combustion position, causing the second contact 772 of the microswitch 77 to be open. The process returns to STEP 9 until the ignition operation is completed, and the error display continues. When the ignition operation is completed, the process proceeds to STEP 7, where the electric fire control valve 73 is switched to the standby state.

[0046] According to the above control, the electric fire control valve 73 is kept in a standby state (fully closed or near fully closed) until the ignition operation is performed. Therefore, if the absence of a cooking vessel is detected during the ignition operation, the electric fire control valve 73 can be immediately fully closed. Therefore, the release of the raw gas when the absence of a cooking vessel is detected during the ignition operation can be prevented without providing the shutoff valve described in Patent Document 1, thereby reducing costs.

[0047] Furthermore, since the electric fire-intensity regulating valve 73 is biased in the opening direction by the biasing mechanism 734, there is virtually no load when the electric fire-intensity regulating valve 73 is moved in the opening direction, thereby enabling the electric motor 735 to rotate at high speed. Therefore, when an ignition operation is performed, if the presence of a cooking vessel is detected, the electric fire-intensity regulating valve 73 can be quickly switched from a standby state to an ignition state (e.g., a maximum fire state) by the high-speed rotation of the electric motor 735, thereby enabling the stove burner 3 to be ignited with good responsiveness.

[0048] The embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited thereto. For example, in the above embodiment, the electric fire control valve 73 is provided with a main valve body 732 and a sub-valve body 733, but a type electric fire control valve having a single valve body may also be used. In addition, the linkage mechanism 736 provided in the electric fire control valve 73 may also be composed of a component other than a feed screw mechanism, such as a rack and pinion mechanism or a cam mechanism. Furthermore, in the above embodiment, the cooking vessel detection mechanism 9 is configured to detect the presence of a cooking vessel on the fire support 4 by raising and lowering the pot bottom temperature sensor 33, but the cooking vessel detection mechanism 9 may also be configured using other mechanisms such as optical sensors.

Claims

1. A gas stove comprising: a stove burner facing a burner opening provided in an opening of a top plate; a fire support provided on the top plate so as to surround the burner opening; a manual operating member for igniting and extinguishing the stove burner; a fire regulating valve for regulating the fire intensity of the stove burner; and a cooking vessel detection mechanism for detecting the presence of a cooking vessel on the fire support, wherein when the operating member performs the ignition operation, if the cooking vessel detection mechanism detects that no cooking vessel is present, the supply of gas to the stove burner is stopped. It is characterized in that The electric fire control valve is configured to be able to freely switch to a fully closed state, which stops the supply of gas to the stove burner. It is biased in the opening direction by a biasing mechanism and is switched to the fully closed state by overcoming the biasing mechanism's force via a direct-acting component driven by an electric motor via a linkage mechanism. When the operating member performs the ignition operation, if the cooking container detection mechanism detects the presence of a cooking container, the electric fire intensity regulating valve is switched to a state in which the fire intensity of the stove burner is at a state suitable for ignition. If the cooking container detection mechanism detects the absence of a cooking container, the electric fire intensity regulating valve is switched to a fully closed state, thereby stopping the supply of gas to the stove burner. When the flameout operation is performed by the operating member, the electric fire control valve is switched to a predetermined standby state and waits until the next ignition operation. The standby state is set to a state near the fully closed state. The standby state is close to the fully closed state and is a minimum fire intensity state in which the fire intensity of the stove burner is minimized.

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