Cooking device

Abstract

To reduce ignition noise in a heating cooker provided with a gas burner as a heat source, wherein a gas 6 having a closing element 6 which rotates to a full open position by ignition operation and a safety valve 6 is interposed in a gas supply passage 6 to the gas burner.SOLUTION: A solenoid valve 6 4 in series with a gas 6 2 and an orifice 6 5 in parallel with the solenoid valve 6 4 are provided in the gas supply passage 6 1. At the time of ignition operation, an ignition means attached to the gas burner is operated with the solenoid valve 64 closed.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a cooking device equipped with a gas burner as a heat source. [Background technology]

[0002] Conventionally, in this type of heating cooker, a safety valve and an electric flow control valve connected in series to the safety valve are provided in the gas supply path to the gas burner, and the amount of gas supplied to the gas burner at the time of ignition is kept relatively small by the electric flow control valve, thereby reducing the ignition noise (see, for example, Patent Document 1).

[0003] The above-mentioned conventional example increases costs due to the provision of an electric flow control valve. To reduce costs, it is desirable to provide a manual flow control valve in series with a safety valve in the gas supply line instead of the electric flow control valve. In this case, the manual flow control valve is generally fully opened during ignition operation, and the safety valve is forcibly opened. Furthermore, an ignition means attached to the gas burner is activated, igniting the gas burner. In this case, ignition occurs when the amount of gas supplied to the gas burner is at its maximum. This increases the possibility of loud ignition noise. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-129298 Summary of the Invention [Problem to be solved by the invention]

[0005] In view of the above, an object of the present invention is to provide a cooking device that can reduce ignition noise despite using a manual flow rate control valve. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention provides a cooking appliance equipped with a gas burner as a heat source, wherein a safety valve and a manual flow control valve in series with the safety valve are disposed in a gas supply path to the gas burner, the safety valve is forcibly opened by an ignition operation, and an ignition means attached to the gas burner is activated to ignite the gas burner; the gas supply path is characterized in that a solenoid valve in series with the manual flow control valve and an orifice in parallel with the solenoid valve are disposed in the gas supply path, and the ignition means is activated with the solenoid valve closed during the ignition operation.

[0007] According to the present invention, even if the manual flow control valve is fully opened during ignition, the solenoid valve connected in series to the manual flow control valve is closed, so the amount of gas supplied to the gas burner during ignition is limited to a small amount determined by the orifice. Therefore, ignition noise can be reduced despite the use of a manual flow control valve. The present invention is suitably applicable to a gas supply line that is provided with a gas cock having a safety valve and a closure as a manual flow control valve, and in which ignition operation using the gas cock's operating knob rotates the closure to the fully open position and forces the safety valve to open.

[0008] In the present invention, it is also desirable that the solenoid valve be opened when a flame detection element attached to the gas burner detects ignition of the gas burner, so that after ignition, the heat power of the gas burner can be adjusted over a wide range using the manual flow control valve without being limited by the orifice.

[0009] After the solenoid valve is opened as described above, it is also possible to close it by the next ignition operation. However, if the ignition operation is performed quickly, the closing element may be rotated to near the fully open position before the solenoid valve is actually closed, and the amount of gas supplied to the gas burner at ignition may exceed the amount determined by the orifice, which may impair the effect of reducing ignition noise.

[0010] Therefore, it is desirable that after the solenoid valve is opened as described above, it is closed when the gas burner is extinguished and maintained in the closed state until the next ignition operation. In this way, even if the next ignition operation is performed quickly, the amount of gas supplied to the gas burner at the time of ignition is reliably limited to the amount determined by the orifice, and the effect of reducing ignition noise is not lost.

[0011] Furthermore, if the solenoid valve is configured as a latching solenoid valve to save power, even if the solenoid valve is closed when the gas burner is extinguished, there is a possibility that the solenoid valve will switch to an open state due to vibration, etc. In this case, the next ignition operation will be performed with the solenoid valve still in the open state, and the effect of reducing ignition noise will not be obtained.

[0012] Therefore, if the solenoid valve is a latching solenoid valve, it is desirable to control the solenoid valve to close during ignition. In this way, even if the solenoid valve is closed when the gas burner is extinguished and then switches to an open state due to vibration or the like, the solenoid valve will close at the next ignition operation, thereby achieving the effect of reducing ignition noise.

[0013] When the fuel gas supplied to the gas burner is hydrogen gas, the possibility of the ignition noise being loud is particularly high, and therefore, it is extremely beneficial to apply the present invention to cases where the fuel gas supplied to the gas burner is hydrogen gas. [Brief explanation of the drawings]

[0014] [Figure 1] 1 is a perspective view of a cooking device according to an embodiment of the present invention; [Figure 2] FIG. 2 is a cross-sectional side view taken along line II-II in FIG. [Figure 3] FIG. 3 is a cross-sectional front view taken along line III-III in FIG. 2. [Figure 4] 1 is a perspective view of a burner unit including a gas burner provided in a cooking device according to an embodiment; [Figure 5] 3 is an enlarged cross-sectional side view of a valve unit for a gas burner provided in the cooking appliance according to the embodiment; FIG. DETAILED DESCRIPTION OF THE INVENTION

[0015] 1 to 3, in a cooking appliance according to an embodiment of the present invention, two orthogonal horizontal directions are defined as X-axis and Y-axis directions. A plurality of (specifically, four) burner units B are arranged in parallel in the Y-axis direction at the top of a body 1 having an open top. The burner units B each include a gas burner 2 elongated in the X-axis direction and a metal hot plate 3 having an upwardly convex cross section (specifically, an upwardly convex arc shape) arranged above the gas burner 2. The hot plate 3 has a plurality of vent holes 31 formed by cutting and raising, through which combustion gas generated by combustion in the gas burners 2 passes. The hot plate 3 is heated to a red heat by combustion in the gas burners 2, and food to be cooked on a grill 4 arranged above the body 1 is heated by the radiant heat radiated from the hot plate 3 and the combustion gas passing through the vent holes 31.

[0016] Grill 4 is placed on a rectangular support frame 42 connected to the upper ends of vertically movable support posts 41 provided on both sides of the body 1 in the Y-axis direction. Support posts 41 are raised and lowered by the vertical swing of an operating lever 43 protruding in one direction of the body 1 in the X-axis direction. A lock lever 44 is attached to operating lever 43, which locks it in any swing position. Pulling lock lever 44 upward releases the lock, allowing the operating lever 43 to swing. A drip tray 5 is also located at the bottom of body 1 so that it can be freely moved in and out in one direction of the X-axis.

[0017] The gas burner 2 comprises a tubular burner body 21 elongated in the X-axis direction, and a plurality of upward-opening flame holes 22 formed along the X-axis direction at the top of the burner body 21. In this embodiment, two adjacent rows of flame holes, each consisting of a plurality of flame holes 22 along the X-axis direction, are provided in the Y-axis direction. Both ends of the burner body 21 in the X-axis direction are closed by plugs 23. Referring to FIG. 4, each plug 23 has a protrusion 231 protruding outward in the X-axis direction. The protrusion 231 of each plug 23 is fastened to support brackets 12 for the burner unit B, which are fixed to frames 11 on both sides of the upper portion of the body 1 in the X-axis direction, thereby fixing and supporting the gas burner 2. Each support bracket 12 also supports each end of the hot plate 3 in the X-axis direction. The gas burner 2 is also provided with an ignition electrode 24 serving as ignition means located above one end in the X-axis direction and a thermocouple 25 serving as flame detection means located above the other end in the X-axis direction.

[0018] Each gas burner 2 is supplied with hydrogen gas as fuel gas via a connection path 61c, which is the downstream end of a gas supply path extending from each valve unit 6 inside a box 13 attached to one surface in the X-axis direction of the body 1. The hydrogen gas then ejects from the flame holes 22 of the gas burners 2 and diffuses and burns. On one outer surface in the X-axis direction of the box 13, there are arranged an operating knob 624 for a gas cock 62 (described in detail below) that is incorporated into each valve unit 6, and a power switch 63 that activates a controller (not shown) for each valve unit 6.

[0019] Furthermore, a partition plate 7 is erected between adjacent burner units B, B in the Y-axis direction. Even if oil or grease dripping from the food being cooked splashes onto the hot plate 3 of each burner unit B or falls along the hot plate 3, the partition plate 7 prevents the oil or grease from adhering to the flame holes 22 of the gas burner 2 of the adjacent burner unit B. The partition plate 7 is supported by inserting the lower ends of both ends in the X-axis direction into slits (not shown) formed in each frame 11 on both sides in the X-axis direction at the top of the appliance body 1. Another partition plate 7 is erected outside the Y-axis direction of the outermost burner unit B in the Y-axis direction.

[0020] Next, the valve unit 6 will be described in detail with reference to FIG. 5. In the following description, one side in the X-axis direction will be referred to as the front side and the other side as the rear side, respectively. The valve unit 6 includes a gas cock 62 disposed in a gas supply path 61 to the gas burner 2 formed inside a valve casing 60. The gas supply path 61 is formed to connect a gas inlet 61a opened at the rear of the lower surface of the valve casing 60 to a gas outlet 61b opened at the upper rear surface of the valve casing 60 and connected to the connection path 61c. A gas nozzle 611 is attached to a portion of the gas supply path 61 near the gas outlet 61b. Hydrogen gas ejected from the gas nozzle 611 is supplied to the gas burner 2 from the gas outlet 61b via the connection path 61c.

[0021] The gas cock 62 has a safety valve 622 and a closing element 621 that serves as a manual flow rate control valve and is connected in series to the safety valve 622. The closing element 621 has a hollow portion 621a that opens rearward toward the safety valve 622, and an outlet (not shown) that communicates with the hollow portion 621a and opens on the outer circumferential surface. The overlapping degree of the communication port and the outlet with respect to the closing element storage space of the gas supply path 61 changes with the rotation of the closing element 621, thereby adjusting the amount of gas supplied to the gas burner 2. In addition, an operating shaft 623 that extends forward and rotates the closing element 621 is provided, and the operating knob 624 is connected to the front end of the operating shaft 623. The operating shaft 623 is connected via a pin 623a to a connector 625 that is inserted into the front end of the closing element 621 so as to be slidable in the front-rear direction while being prevented from rotating. The rotation of the operating shaft 623 causes the closing element 621 to rotate via the pin 623 a and the connector 625 .

[0022] The safety valve 622 includes a valve seat 622b formed at the front end of a valve chamber 622a communicating with the gas inlet 61a, a valve element 622c in the valve chamber 622a facing the valve seat 622b, a valve spring 622d that biases the valve element 622c in the closing direction toward the valve seat 622b, an attracting piece 622e connected to the valve element 622c via a shaft extending rearward, and an electromagnet 622f facing the rear of the attracting piece 622e. The operating shaft 623 can be pushed rearward against a spring 625a that biases a connector 625 forward. A pressing rod 626 extending rearward from the connector 625 faces the front of the valve element 622c. Then, by pushing the operating shaft 623, the pressing rod 626 is pushed rearward via the connector 625 to abut against the valve element 622c, and the valve element 622c is pushed to the valve open position where the attracting piece 622e abuts against the electromagnet 622f, thereby forcibly opening the safety valve 622. By energizing the electromagnet 622f in this state, the valve element 622c is attracted and held in the valve open position.

[0023] The gas cock 62 is also provided with a microswitch 627 that is pressed and turned on by a cam 623b that rotates integrally with the operating shaft 623 when the operating shaft 623 is rotated from its stopped position. When the ignition operation is performed by pushing and turning the operating knob 624 from its stopped position, the closure 621 rotates to the fully open position and the safety valve 622 is forcibly opened as described above, and further, when the microswitch 627 is turned on, the ignition means is activated by the controller, that is, a spark discharge occurs at the ignition electrode 24, igniting the gas burner 2. When the microswitch 627 is turned on, the controller also starts energizing the electromagnet 622f of the safety valve 622, and energization to the electromagnet 622f continues for a predetermined time even after the pushing operation of the operating knob 624 is released. Then, if the thermocouple 25 detects ignition of the gas burner 2 within this predetermined time, the controller continues to energize the electromagnet 622f, maintaining the open state of the safety valve 622. On the other hand, if ignition is not detected within the predetermined time or if a flame is no longer detected by the thermocouple 25 due to a misfire during combustion, the controller stops energizing the electromagnet 622f, closing the safety valve 622 and preventing the release of raw gas.

[0024] However, when the ignition operation rotates the closing element 621 to the fully open position, and the gas supply amount to the gas burner 2 is maximized when the ignition is performed, the ignition noise is likely to become louder. When the fuel gas is hydrogen gas as in this embodiment, the possibility of this occurring is particularly high.

[0025] Therefore, in this embodiment, the valve unit 6 is provided with a valve valve 62 in series, i.e., a valve valve 63 It incorporates a solenoid valve 64 that is disposed in gas supply path 61 in series with (manual flow control valve) 621, and an orifice 65 that is disposed in gas supply path 61 in parallel with solenoid valve 64. Solenoid valve 64 is configured as a latch-type solenoid valve that includes a valve seat 642 at the rear end of a valve chamber 641 formed in the middle of gas supply path 61, a valve element 643 in valve chamber 641 that faces valve seat 642, a valve spring 644 that urges valve element 643 toward the closing side toward the rear approaching valve seat 642, a plunger 645 that extends forward from valve element 643, a coil 647 wound around bobbin 646 into which plunger 645 is slidably inserted, a core 648 fixed in bobbin 646 so as to face the front of plunger 645, and a permanent magnet 649 joined to core 648. When the coil 647 is energized and the plunger 645 is moved forward while the solenoid valve 64 is closed with the valve disc 643 seated on the valve seat 642, the valve disc 643 separates from the valve seat 642, opening the solenoid valve 64. The plunger 645 is then attracted to the core 648, and the solenoid valve 64 remains open even when the supply of current to the coil 647 is stopped. When the coil 647 is energized in the closing direction, which is opposite to the above-mentioned energization direction, while the solenoid valve 64 is open, the electromagnetic force generated by the coil 647 overcomes the magnetic force of the permanent magnet 649 acting via the core 648, and the biasing force of the valve spring 644 seats the valve disc 643 on the valve seat 642, closing the solenoid valve 64. Thereafter, the closed state is maintained even when the supply of current to the coil 647 is stopped.

[0026] During ignition, the solenoid valve 64 is closed and spark discharge occurs at the ignition electrode 24. This limits the amount of gas supplied to the gas burner 2 to a small amount determined by the orifice 65, even if the closure 621 is rotated to the fully open position during ignition. Therefore, even though the gas cock 62 is used, ignition noise can be reduced.

[0027] Furthermore, the solenoid valve 64 is opened by the controller when the ignition of the gas burner 2 is detected by the thermocouple 25. Therefore, after ignition, the heat power of the gas burner 2 can be adjusted over a wide range by rotating the closing element 621 without being restricted by the orifice 65.

[0028] Incidentally, after opening the solenoid valve 64 as described above, it is also possible to close the solenoid valve 64 by the next ignition operation. However, in this case, if the ignition operation is performed quickly, the closing element 621 may be rotated close to the fully open position before the solenoid valve 64 is actually closed, and the amount of gas supplied to the gas burner 2 at the time of ignition may become larger than the amount determined by the orifice 65, which may impair the effect of reducing the ignition noise.

[0029] Therefore, in this embodiment, after opening the solenoid valve 64 as described above, when the gas burner 2 is extinguished, specifically when the microswitch 627 is turned off by turning the operation knob 624 to the off position or when extinguishing is detected by the thermocouple 25, the controller closes the solenoid valve 64 and maintains the solenoid valve 64 in the closed state until the next ignition operation. According to this, even if the next ignition operation is performed quickly, the amount of gas supplied to the gas burner 2 at the time of ignition is reliably limited to the amount specified by the orifice 65, and the effect of reducing the ignition noise is not impaired.

[0030] If solenoid valve 64 is configured as a latching solenoid valve, when the cooking appliance is not in use, vibrations or the like may cause plunger 645 of solenoid valve 64 to move close to core 648 and be attracted to core 648, opening solenoid valve 64. In this case, the next ignition operation will be performed with solenoid valve 64 remaining in the open state, and the effect of reducing ignition noise will not be obtained.

[0031] Therefore, in this embodiment, when the microswitch 627 is turned on during the ignition operation, the controller controls to close the solenoid valve 64, that is, controls to energize the coil 647 in the closing direction. According to this, even if the solenoid valve 64 is switched to the open state due to vibration or the like after the solenoid valve 64 is closed when the gas burner 2 is extinguished, the solenoid valve 64 will be closed at the next ignition operation, thereby achieving the effect of reducing the ignition noise.

[0032] Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited thereto. For example, a bypass path having a smaller pipeline resistance than the orifice 65 may be provided in parallel with the solenoid valve 64 and orifice 65 of the above embodiment, and a second solenoid valve may be interposed in this bypass path. In this case, when ignition is detected, the second solenoid valve opens a predetermined short time (e.g., 0.5 seconds) earlier than the opening of the solenoid valve 64. This allows the amount of gas supplied to the gas burner 2 to increase stepwise after ignition, thereby reducing the loud combustion switching noise that tends to occur when the amount of gas supplied is suddenly increased.

[0033] Furthermore, in the above embodiment, the ignition operation using the operating knob 624 of the gas cock 62 is performed by pushing and turning the operating knob 624 from its stopped position, but it is also possible to install a cam mechanism between the operating shaft 623 and the pressing rod 626, which pushes the pressing rod 626 rearward with the rotation of the operating shaft 623, so that the ignition operation is performed simply by rotating the operating knob 624 from its stopped position. Furthermore, the present invention can also be applied to a configuration in which, instead of a gas cock, a safety valve and a manual flow rate control valve operated by a flame power adjustment lever connected in series to the safety valve are installed in the gas supply path, and the safety valve is forced open when the ignition operation is performed by pressing a push-type operating button, and the manual flow rate control valve is set to a predetermined ignition opening by a mechanism linked to the operating button.

[0034] Furthermore, the fuel gas supplied to the gas burner 2 can be a gas other than the hydrogen gas of the above embodiment. However, applying the present invention when the fuel gas is hydrogen gas is very beneficial in preventing an increase in ignition noise that is likely to occur with hydrogen gas. Furthermore, although the cooking device in the above embodiment is for grilling, the present invention can also be applied to cooking devices other than those for grilling, such as stoves. [Explanation of symbols]

[0035] 2...Gas burner, 24...Ignition electrode (ignition means), 25...Thermocouple (flame detection element), 61...Gas supply path, 62...Gas cock, 621...Closer, 622...Safety valve, 624...Operating knob, 64...Solenoid valve, 65...Orifice.

Claims

1. A cooking appliance equipped with a gas burner as a heat source, in which a safety valve and a manual flow control valve connected in series to the safety valve are interposed in a gas supply path to the gas burner, the safety valve is forced open by an ignition operation, and further, an ignition means attached to the gas burner is activated to ignite the gas burner, This cooking device is characterized in that a gas supply path is provided with a solenoid valve in series with a manual flow control valve and an orifice in parallel with the solenoid valve, and when an ignition operation is performed, the ignition means is activated with the solenoid valve closed.

2. 2. The cooking device according to claim 1, wherein a gas cock having the safety valve and a closure as the manual flow rate control valve is interposed in the gas supply path, and when an ignition operation is performed using an operating knob of the gas cock, the closure rotates to a fully open position and the safety valve is forcibly opened.

3. 2. The cooking device according to claim 1, wherein the solenoid valve is opened when ignition of the gas burner is detected by a flame detection element attached to the gas burner.

4. 4. The cooking device according to claim 3, wherein the solenoid valve is closed when the gas burner is extinguished and is maintained in a closed state until the next ignition operation.

5. 5. The cooking device according to claim 4, wherein the solenoid valve is a latch-type solenoid valve, and the solenoid valve is controlled to close when the ignition operation is performed.

6. 6. The cooking device according to claim 1, wherein the fuel gas supplied to the gas burner is hydrogen gas.

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