JP2005077041A - Gas stove - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the reduction in durability by the rise of temperature of a glass top plate 2 by combustion with heating object P to be heated removed, in a gas stove in which a combustion case 3 the upper surface of which is closed by the glass top plate is arranged on the lower side of the glass top plate 2, and a surface combusion type burner 4 is installed to the lower part of the combustion case with the combustion surface upward to heat the heating object P placed on the upper surface of the glass top plate. <P>SOLUTION: A temperature sensor 11 is provided within the combustion case 3 to determine the presence/absence of the matter P based on a change in the temperature detected by the temperature sensor 11. When the absence of the heating object is determined, the combustion quantity of the burner 4 is reduced. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a so-called full flat type gas stove using a glass top plate that does not have a burner opening as the top plate.

  Conventionally, as this type of gas stove, a combustion casing whose upper surface is closed by the glass top plate is arranged below the glass top plate, and a surface combustion type burner is mounted at the bottom of the combustion casing with the combustion surface facing upward. And what heated the to-be-heated material, such as a pan mounted in the upper surface of a glass top plate, is known (for example, refer patent document 1).

In this case, the burner is formed in an annular shape, a radiator having air permeability is attached to the inner diameter portion of the burner, and the combustion exhaust gas in the combustion casing is exhausted through the radiator to add to the combustion surface of the burner. The radiant body is also heated red, and the object to be heated is heated via the glass top plate by the radiant heat from the combustion surface and the radiant body and the heat of the combustion exhaust gas.
JP 2002-206713 A

  By the way, although the glass top plate is formed with heat-resistant glass, such as ceramic glass, when temperature becomes high, it will produce thermal degradation. And if the temperature of a glass top plate becomes higher than the temperature which begins to produce thermal degradation, the lifetime of a glass top plate will reduce geometrically. Therefore, conventionally, even when the heating power is set to the maximum, the burner combustion amount is controlled so that the temperature of the glass top plate does not rise above a predetermined temperature, and the required service life is ensured. However, if the object to be heated on the glass top plate is removed during burner combustion, the temperature of the glass top plate rises above the deterioration start temperature and the service life is shortened.

  In addition, in a household stove where the use time of a day is limited, unless the temperature of the glass top plate rises excessively, the glass top plate hardly reaches the service limit before reaching the service limit of the stove itself. . However, in a commercial stove, the glass top plate may reach the end of its service life first, which may necessitate the replacement of the glass top plate.

  In view of the above, it is a first object of the present invention to provide a gas stove that can suppress an increase in temperature of a glass top plate due to removal of an object to be heated. In view of shortening the service life due to temperature rise, a second object is to provide a gas stove that can notify when the glass top plate reaches the service life limit.

  In order to solve the first problem, according to a first feature of the present invention, a combustion housing whose upper surface is closed by a glass top plate is disposed below the glass top plate, and combustion is performed at a lower portion of the combustion housing. Discrimination to determine the presence or absence of an object to be heated on the glass top plate in a gas stove that is equipped with a surface-burning burner with the surface facing upward to heat the object to be heated placed on the top surface of the glass top plate When it is determined that there is no object to be heated, the combustion of the burner is stopped, or the heating reduction process for reducing the burner combustion amount is executed.

  According to said structure, when the to-be-heated object on a glass top plate is removed, it will be discriminate | determined by a discrimination | determination means that there will be no to-be-heated object, a heating reduction process will be performed, and the temperature rise of a glass top plate will be suppressed. Therefore, shortening of the service life of the glass top plate can be avoided.

  In order to solve the second problem, according to a second feature of the present invention, a combustion casing whose upper surface is closed by a glass top plate is disposed below the glass top plate, In a gas stove that is equipped with a surface-burning burner with the combustion surface facing upward to heat the object to be heated placed on the top surface of the glass top plate, the presence or absence of the object to be heated on the glass top plate is determined. The amount of combustion at which the glass top plate is heated to a predetermined temperature or more by combustion of the burner in a state where it is determined that there is no object to be heated by the determining means and no object to be heated A time measuring means for measuring the cumulative combustion time burned at the time, a life determining means for determining whether or not the glass top plate has reached the service life limit based on the cumulative combustion time measured by the time measuring means, and a life determining means When it is determined that the glass top has reached its service life limit, And an informing means for informing a fact.

  Here, if the predetermined temperature is set according to the temperature at which the glass top plate starts to deteriorate, the temperature of the glass top plate rises by removing the heated object on the glass top plate during combustion. If the glass top reaches the end of its service life even if the service life is shortened and the service life is shortened, this is notified and the replacement of the glass top is encouraged. It is possible to avoid a situation where it breaks easily.

  By the way, the service life of the glass top plate decreases as the temperature rises. Considering this, it is desirable that the second feature of the present invention is configured as follows. Note that the combustion amount at which the glass top plate is heated to the first predetermined temperature by burning the burner in the absence of an object to be heated is defined as the first combustion amount, the second combustion temperature higher than the first predetermined temperature. The amount of combustion at which the temperature is raised to a predetermined temperature is defined as the second combustion amount. And as the time measuring means of the second feature of the present invention, the first time measuring means for measuring the accumulated combustion time at the first combustion amount in the state where the object to be heated is determined to be absent by the determining means, and the determining means A second timing means for measuring the cumulative combustion time at the second combustion amount in a state where it is determined that there is no object to be heated, and multiplying the cumulative combustion time measured by the second measurement means by a predetermined coefficient Whether the total time of the obtained time and the cumulative combustion time measured by the first measuring means has reached the service life at the first predetermined temperature of the glass top plate is determined by the life determining means, and the total time Is notified by the notification means when the service life is reached.

  Here, the first predetermined temperature is set to, for example, a temperature at which the glass top plate starts to deteriorate (deterioration start temperature). If the temperature is lower than this temperature, the service life is almost infinite. On the other hand, when the glass top is heated to the second predetermined temperature, the service life is shorter than the service time at the first predetermined temperature. Therefore, if the cumulative combustion time measured by the second measuring means and the cumulative combustion time measured by the first measuring means are simply summed, the total time is before reaching the service life at the first predetermined temperature. In addition, the lifetime of the glass top plate may be exhausted.

  On the other hand, according to the above configuration, the time obtained by multiplying the cumulative combustion time measured by the second measuring means by a predetermined coefficient and the cumulative combustion time measured by the first measuring means are summed. The total time is compared with the service life at the first predetermined temperature. And if the said coefficient is set to the value according to the ratio of the durable time in 1st predetermined temperature and the durable time in 2nd predetermined temperature, this coefficient will be added to the cumulative combustion time measured by the 2nd measurement means. By multiplying by, it is possible to obtain the time corresponding to the passage of the service life at the first predetermined temperature. Therefore, it is possible to prevent the glass top plate from being exhausted before the total time reaches the service life. And when the total time reaches the service life, it is possible to prompt the exchange of the glass top plate by notifying this with the notification means, and avoid the situation where the glass top plate is inadvertently broken due to thermal deterioration during use. .

  By the way, when the object to be heated on the glass top plate is removed, the temperature of the glass top plate and the temperature in the combustion housing change. Therefore, a temperature sensor is provided in the combustion housing, and the presence or absence of an object to be heated can be determined based on a change in temperature detected by the temperature sensor. In this case, if a rod-type temperature sensor with a cladding tube covering the thermal element is used and the temperature sensor is arranged so as to reach the center of the combustion housing from the rear of the combustion housing in a plan view, the object to be heated is placed on the glass top. When the object to be heated is removed from the position directly above the temperature sensor by shifting it in the horizontal direction or forward on the plate, the temperature detected by the temperature sensor changes and it is determined that there is no object to be heated. Here, the portion of the glass top plate that has come off from the object to be heated due to the deviation of the object to be heated rises, but when the object to be heated is displaced, it is determined that there is no object to be heated as described above. Heating reduction processing and time measurement processing for life determination are performed, and occurrence of unforeseen situations due to temperature rise caused by deviation of the object to be heated can be avoided.

  In the embodiment to be described later, the determination means corresponds to the step S11 in FIG. 6 and the step S211 in FIG. 10, and the first time measurement means corresponds to the step S104 in FIG. The step corresponding to the second time measuring means is step S105 in FIG. 7, and the steps corresponding to the life determination means are steps S106 and S107 in FIG.

  Referring to FIG. 1, reference numeral 1 denotes a stove body of a full flat type gas stove, and a glass top plate 2 made of heat-resistant glass such as ceramic glass is mounted on the upper surface of the stove body 1. As shown in FIG. 2, a cylindrical combustion housing 3 is disposed in the stove body 1, and the flange 3a at the upper end of the combustion housing 3 is brought into airtight contact with the lower surface of the glass top plate 2 through the packing 3b. The upper surface of the combustion housing 3 is closed by the glass top plate 2. An annular surface combustion burner 4 is provided at the lower portion of the combustion housing 3 with the combustion surface 4a facing upward. In addition, a radiator 5 made of a porous material having air permeability made of an assembly of ceramic fibers or the like is disposed on the inner diameter portion of the burner 4. Note that the combustion surface 4 a of the burner 4 is also formed of a porous material similar to the radiator 5.

  The stove body 1 is further supplied with gas supply means 6 for supplying fuel gas to the burner 4, supply of combustion air to the burner 3, and supply of combustion exhaust gas in the combustion housing 3 through the radiator 5. Exhaust means 7 is arranged. The air supply / exhaust means 7 includes an air supply passage 71 that communicates with the burner 4, an exhaust passage 73 that communicates the space below the radiator 5 with the exhaust port 72 at the rear upper surface of the stove body 1, and the upstream of the air supply passage 71. It is comprised with the fan 74 provided in the edge. The gas supply means 6 includes a nozzle 61 connected to the air supply passage 71, a gas passage 62 communicating with the nozzle 61, an upstream electromagnetic on-off valve 63 provided in the gas passage 62, and a downstream electromagnetic proportionality. The fuel gas ejected from the nozzle 61 is mixed with the air from the fan 74 and supplied to the burner 4 as an air-fuel mixture. During combustion of the burner 4, the combustion surface 4 a is red-heated, and the radiator 5 is also red-heated by the heat of the combustion exhaust gas passing through the radiator 5, so that a heated object P such as a pan placed on the glass top plate 2. Is heated through the glass top plate 2 by the radiant heat from the combustion surface 4 a and the radiator 5 and the heat of the combustion exhaust gas in the combustion housing 3.

  The electromagnetic on-off valve 63, the electromagnetic proportional valve 64, and the fan 74 are controlled by a controller 8 composed of a microcomputer. The controller 8 is supplied with a signal from a thermal power regulator 9 also serving as an ignition switch provided on the front surface of the stove body 1 and a detection signal from an exhaust temperature sensor 10 provided in the exhaust passage 73. The thermal power regulator 9 is configured so that the thermal power can be variably set in a plurality of stages, for example, four stages from the minimum “1” to the maximum “4”. Then, the exhaust temperature corresponding to each thermal power is set, and the burner is controlled by controlling the electromagnetic proportional valve 64 and the fan 74 so that the temperature detected by the exhaust temperature sensor 10 becomes the set exhaust temperature corresponding to the thermal power set by the thermal power regulator 9. 4 is controlled.

  The set exhaust gas temperature is set to, for example, 100 ° C. when the thermal power is “1”, 200 ° C. when the thermal power is “2”, 300 ° C. when the thermal power is “3”, and 450 ° C. when the thermal power is “4”. Even when the amount of combustion is controlled so that the set thermal power is “4” and the exhaust temperature is 450 ° C., if the heated object P is placed on the glass top 2, the temperature of the glass top 2 is At about 350 ° C., it does not rise to a temperature at which thermal degradation begins to occur (degradation start temperature, for example, 600 ° C.). However, when there is no object to be heated P on the glass top plate 2, the temperature of the glass top plate 2 may rise above the deterioration start temperature. Here, the service life (life) of the glass top plate 2 decreases geometrically when the temperature of the glass top plate 2 becomes higher than the deterioration start temperature. For example, when the service life at the deterioration start temperature is 5000 hours, it is 1000 hours when it is 50 ° C. higher than the heat deterioration start temperature, 100 hours when it is 100 ° C. higher than the deterioration start temperature, and 10 hours when it is 150 ° C. higher than the deterioration start temperature. Become. Accordingly, it is necessary to determine the presence or absence of the object to be heated P and to suppress the temperature rise of the glass top plate 2 when there is no object to be heated P. Therefore, in the present embodiment, the temperature sensor 11 is provided in the combustion housing 3, and the detection signal of the temperature sensor 11 is input to the controller 8 so that the object P to be heated on the glass top plate 2 will be described in detail later. The presence or absence is determined.

  The temperature sensor 11 is a rod-shaped type in which a thermal element such as a thermocouple is covered with a cladding tube, and is constituted by a CA thermocouple sensor, for example. As shown in FIG. 4, the temperature sensor 11 is arranged so as to reach the center of the combustion housing 3 from the rear of the combustion housing 3 in plan view. In this case, it is possible to support the temperature sensor 11 in a cantilever state on the rear wall of the combustion housing 3, but in this case, the temperature sensor 11 is easily inclined, and the temperature sensor 11, the glass top plate 2, The vertical distance between them varies. Therefore, in the present embodiment, a bowl-shaped support member 12 having an open upper surface as shown in FIG. 3 is provided at the upper portion of the combustion housing 3 so as to be close to and opposed to the lower surface of the glass top plate 2. The temperature sensor 11 is supported. The support member 12 is supported at both ends by the front and rear portions of the flange 3a at the upper end of the combustion housing 3 in a state where the support member 12 is positioned on the diameter line in the front-rear direction passing through the center in the combustion housing 3. It is stably supported by the support member 12 at a position near the lower surface of the glass top plate 2.

  Further, the glass top plate 2 comes into contact with the support member 12 and the temperature sensor 11 due to bending of the glass top plate 2 when a heavy object is placed on the glass top plate 2, vibration during transportation, or the like. 2 and the temperature sensor 11 are not damaged, a slight gap (for example, 2 to 3 mm) is provided between the support member 12 and the glass top plate 2, and the support member 12 is positioned below its upper edge. The temperature sensor 11 is arranged so as to be accommodated, and a gap (for example, 8 to 10 mm) is also formed between the temperature sensor 11 and the glass top plate 2. In addition, it is also possible to close the gap between the support member 12 and the glass top plate 2 by attaching an elastic packing to the upper edge portion of the support member 12.

  The temperature sensor 11 is covered with a heat insulating material 13 such as glass wool except for the upper surface portion facing the glass top plate 2, and is supported by the support member 12 via the heat insulating material 13. By encapsulating the temperature sensor 11 with the heat insulating material 13 in this way, the thermal effect of the combustion exhaust gas on the temperature sensor 11 and the thermal effect of the radiant heat from the combustion surface 4 a and the radiator 5 are reduced. And the thermal effect from the glass top plate 2 is applied to the upper surface portion of the temperature sensor 11 that is not encapsulated with the heat insulating material 13, and even if the temperature sensor 11 is not brought into contact with the glass top plate 2, the detected temperature of the temperature sensor 11. Changes with high sensitivity according to the temperature of the glass top plate 2.

  FIG. 5 shows temperature measurement results during combustion with the thermal power “4”. In FIG. 5, the a line indicates the temperature detected by the temperature sensor 11, the b line indicates the temperature of the glass top plate 2, and the c line indicates the exhaust temperature sensor 10. Is the detected temperature. The period d in the figure is a period in which the object to be heated P on the glass top plate 2 is removed. When the object to be heated P is removed, the temperature of the glass top plate 2 rises, and the temperature sensor 11 detects the temperature accordingly. Although the temperature rises, it can be seen that the temperature detected by the exhaust temperature sensor 10 hardly changes. The temperature detected by the temperature sensor 11 is higher than the temperature of the glass top plate 2. This is due to the influence of a small amount of combustion exhaust gas that inevitably goes around the upper surface side of the temperature sensor 11, but the influence of the combustion exhaust gas is not so great as to the left. The temperature detected by the temperature sensor 11 rises with high sensitivity under the influence of heat from the glass top plate 2 due to the temperature rise. Moreover, the a 'line | wire of FIG. 5 has shown the change of the detected temperature of the temperature sensor 11 when combustion is started without mounting the to-be-heated material P on the glass top plate 2, and there exists to-be-heated material P. Compared to the case, the time until the detected temperature rises to the first set temperature YTG1 described later is shortened.

  The controller 8 determines the presence or absence of the object P to be heated on the glass top plate 2 based on the change in the temperature detected by the temperature sensor 11. Details of the presence / absence determination processing of the article to be heated P are as shown in FIG. 6, and will be described in detail below. First, a timer is started at the time of ignition (S1), and after ignition, the operation is performed with the heating power “4” regardless of the set heating power (S2). Then, it is determined whether or not the detected temperature TG of the temperature sensor 11 has risen to a predetermined first set temperature YTG1 (for example, 600 ° C.) (S3), and when TG ≧ YTG1, the ignition is measured by a timer. It is determined whether the elapsed time t from the time is within a predetermined set time Yt (S4). The set time Yt is the time required for the temperature TG detected by the temperature sensor 11 to rise to the predetermined first set temperature YTG1. If the object to be heated P is not placed on the glass top 2, Yt When the object P is short and is placed on the glass top plate 2, the time is set to be longer than Yt. And if t <= Yt, it will judge that the to-be-heated object P is not mounted on the glass top plate 2 (no to-be-heated object), and the to-be-heated object P will display the to-be-heated object P presence-indication flag FP. It is set to “0” indicating that there is not (S5), and the operation is switched to the operation with the heating power “3” (S13).

  When t> Yt, the flag FP is set to “1” indicating that the article to be heated P is present (S6), and then the operation is shifted to the set heating power (S7). Next, is the detected temperature TH of the exhaust temperature sensor 10 higher than a predetermined exhaust temperature of the heating power “2” and higher than a predetermined first exhaust temperature YTH1 (for example, 250 ° C.) lower than the setting exhaust temperature of the heating power “3”? It is determined whether or not (S8). Here, there is a possibility that the temperature of the glass top plate 2 rises above the deterioration start temperature due to heating in a state where the article to be heated P is not placed, mainly during combustion at a thermal power of “3” or more. In order to determine whether or not the thermal power is “3” or more, a step S8 is provided. Note that the thermal power determination is performed based on the exhaust temperature because an exhaust temperature overshoot occurs when the combustion amount is controlled so that the detected temperature TH of the exhaust temperature sensor 10 becomes the set exhaust temperature corresponding to the set thermal power, This is because the temperature of the glass top plate 2 may temporarily rise to the deterioration start temperature even when the thermal power “2” is burned.

  If it is determined in the step S8 that TH ≧ YTH1, it is next determined whether or not the detected temperature TG of the temperature sensor 11 is equal to or higher than the second set temperature YTG2 (S9). The second set temperature YTG2 is set to a temperature detected by the temperature sensor 11 (for example, 560 ° C.) during combustion with the heating power “3” in a state where the article to be heated P is placed. When TG ≧ YTG2, a change in the detected temperature TG is monitored, and when the detected temperature TG becomes stable, the temperature is stored as an equilibrium temperature (S10).

  Thereafter, when the detected temperature TG rises from the equilibrium temperature by a predetermined temperature ΔT (for example, 20 ° C.) (S11), it is determined that the object to be heated P on the glass top plate 2 has been removed (no object to be heated), The flag FP is reset to “0” (S12), and even if the set thermal power is “4”, the operation is forcibly switched to the operation with the thermal power “3” to reduce the combustion amount (S13). Thereafter, if the detected temperature TG of the temperature sensor 11 does not decrease until a predetermined time (for example, 30 seconds) elapses (S14), the combustion of the burner 4 is stopped (S15), and when the detected temperature TG decreases, It is determined that the article to be heated P has been placed again, the flag FP is set to “1” (S16), and the operation is returned to the set heating power (S7).

  When it is determined that there is no object to be heated, the heating power may be switched to “2” in step S13. However, when the object to be heated P is temporarily removed and reheated, the heating power is set to “2”. If it is lowered to a value, a heating delay occurs during reheating. Therefore, in this embodiment, the heating power is switched to “3” in step S13. In the case of the thermal power “3”, the glass top plate 2 rises only to the deterioration start temperature even without an object to be heated, and a sufficient service life can be secured. Further, the combustion may be continued with the heating power set to the minimum “1” without stopping the combustion in step S15.

  Moreover, in this embodiment, the process for lifetime determination of the glass top plate 2 is also performed by the subroutine. The life determination process is repeatedly executed at regular time intervals, and details thereof are as shown in FIG. In the life determination process, first, it is determined whether or not the flag FP is “0” (S101). If FP = 0, the detected temperature TH of the exhaust temperature sensor 10 is equal to or higher than the first exhaust temperature YTH1. It is determined whether or not there is (S102), and if TH ≧ YTH1, a predetermined second exhaust temperature YTH2 where the detected temperature TH is higher than the set exhaust temperature of the thermal power “3” and lower than the set exhaust temperature of the thermal power “4”. It is determined whether or not (for example, 350 ° C.) or higher (S103).

  If YTH1 ≦ TH <YTH2, 1 is added to the previous value of the first timer count value C1 (S104), and if TH ≧ YTH2, 1 is added to the previous value of the second timer count value C2. Addition is performed (S105). Here, YTH1 ≦ TH <YTH2 is basically during combustion with the heating power “3”, and the first timer count value C1 is the heating power “3” in the state where there is substantially no heated object P. It represents the cumulative combustion time at. Further, TH ≧ YTH2 is basically during combustion with the heating power “4”, and the second timer count value C2 is the cumulative value with the heating power “4” in the absence of the object P to be heated. It represents the burning time. In this embodiment, when it is determined that there is no object to be heated at the time of combustion with the thermal power “4”, since the thermal power is switched to “3” in step S13 in FIG. 6, the first timer count value C1 is usually added. However, the second timer count value C2 is added while TH ≧ YTH2 in the process until the combustion amount is reduced to the equivalent of the thermal power “3”.

  Next, a total value A of a value obtained by multiplying the second timer count value C2 by a predetermined coefficient K and the first timer count value C1 is obtained (S106), and the total value A is compared with a predetermined life determination value B. Then, it is determined whether or not A <B (S107). Here, the lifetime determination value B is set in accordance with the service life at the deterioration start temperature of the glass top plate 2. The temperature of the glass top plate 2 at the time of combustion with the thermal power “3” in the state without the heated object P is substantially equal to the deterioration start temperature, but at the time of combustion with the thermal power “4” without the heated object P The temperature of the glass top plate 2 is about 50 ° C. higher than the deterioration start temperature, and the service life at this temperature is about 1/5 of the service life at the deterioration start temperature. Therefore, the second timer count value C2 representing the cumulative combustion time at the heating power “4” in the state where there is no object to be heated P can be compared with the life judgment value B set in accordance with the service life at the deterioration start temperature. In order to convert to, the second timer count value C2 needs to be multiplied by five. In addition, the temperature of the glass top plate 2 may be higher than the deterioration start temperature by 50 ° C. or more during combustion at a combustion amount equivalent to the heating power “4” in the absence of the object P to be heated. Therefore, considering the safety factor, the coefficient K is set to 10, for example, and the value A corresponding to the accumulated time when the temperature of the glass top plate 2 becomes the deterioration start temperature is obtained by the equation A = C1 + K · C2. Yes.

  When A = B, it is determined that the glass top plate 2 has reached the service life limit, and the display lamp 14 serving as a notification means provided on the front surface of the stove body 1 is turned on in an appropriate form. Is notified to the user (S108) and prompts the user to replace the glass top plate 2. Thereby, the malfunction that the lifetime of the glass top plate 2 runs out during use and the glass top plate 2 breaks carelessly can be avoided.

  Further, the object to be heated P may be shifted left and right or forward on the glass top plate 2 as indicated by phantom lines in FIG. 4, and the temperature of the portion of the glass top plate 2 that has come off from the object to be heated P due to this displacement. May rise above the deterioration start temperature. In addition, since the exhaust port 72 exists in the back of the glass top plate 2, the to-be-heated material P is hardly shifted back. Here, in this embodiment, the temperature sensor 11 is disposed so as to reach the center of the combustion housing 3 from the rear of the combustion housing 3 in plan view. Accordingly, when the object to be heated P is shifted on the glass top plate 2, the object to be heated P is removed from the position directly above the temperature sensor 11, and the temperature TG detected by the temperature sensor 11 is increased by the temperature rise of the glass top plate 2 at this portion. Is also increased, and it is determined in step S11 in FIG. 6 that there is no object to be heated. Therefore, a combustion amount reduction process in step S13 and a time measurement process for life determination in steps S104 and S105 are executed to avoid occurrence of an unexpected situation due to a temperature rise caused by the deviation of the object P to be heated. it can.

  As described above, the first embodiment in which the temperature sensor 11 is encapsulated with the heat insulating material 13 and disposed near the lower surface of the glass top plate 2 has been described. However, as in the second embodiment shown in FIG. The temperature sensor 11 may be arranged in the combustion housing 3 without being wrapped. In the second embodiment, in order to prevent the distance from the glass top plate 2 from varying due to the inclination of the temperature sensor 11, the support pipe 15 located on the diameter line in the front-rear direction is attached to the combustion housing 3. The temperature sensor 11 is inserted into the support pipe 15 so as to reach the center of the combustion casing 3 from the rear of the combustion casing 3. In addition, the distance between the temperature sensor 11 and the glass top plate 2 is set to about 10 mm.

  FIG. 9 shows a temperature measurement result at the time of combustion at the thermal power “4” in the second embodiment, in which a line is a detected temperature of the temperature sensor 11, b line is a temperature of the glass top plate 2, The c line is the temperature detected by the exhaust temperature sensor 10. In the second embodiment, the temperature sensor 11 receives heat from the combustion exhaust gas, and the detected temperature is considerably higher than the temperature of the glass top plate 2. The period d in the figure is a period in which the object to be heated P on the glass top plate 2 is removed. When the object to be heated P is removed, the temperature detected by the temperature sensor 11 decreases. This is considered because the reflected radiant heat from the bottom surface of the object to be heated P on the glass top plate 2 does not reach the temperature sensor 11 by removing the object to be heated P. Moreover, the a 'line of FIG. 9 has shown the change of the detected temperature of the temperature sensor 11 when combustion is started without mounting the to-be-heated object P on the glass top plate 2, The bottom face of the to-be-heated object P Therefore, the time until the detected temperature rises to the first set temperature YTG1, which will be described later, becomes longer than when the object to be heated P is present.

  FIG. 10 shows the presence / absence determination processing of the object P to be heated in the second embodiment. In this process, as in the first embodiment, first, a timer is started at the time of ignition (S201), and after ignition, the operation is performed with the heating power “4” regardless of the set heating power (S202). Then, it is determined whether or not the detected temperature TG of the temperature sensor 11 has risen to a predetermined first set temperature YTG1 (for example, 700 ° C.) (S203), and when TG ≧ YTG1, ignition is timed by a timer. It is determined whether the elapsed time t from the time is within a predetermined set time Yt (S204). The set time Yt is the time required for the temperature TG detected by the temperature sensor 11 to rise to the predetermined first set temperature YTG1. If the object to be heated P is not placed on the glass top 2, Yt The time is set to be shorter than Yt when the object P to be heated is placed on the glass top plate 2 for a long time. If t> Yt, it is determined that the object to be heated P is not placed on the glass top plate 2 (no object to be heated), and the object to be heated P displays the presence / absence display flag FP of the object to be heated. It is set to “0” indicating that there is not (S205), and the operation is switched to the operation with the heating power “3” (S213).

  When t ≦ Yt, the flag FP is set to “1” indicating that the article to be heated P is present (S206), and then the operation is shifted to the set heating power (S207). Next, is the detected temperature TH of the exhaust temperature sensor 10 higher than a predetermined exhaust temperature of the heating power “2” and higher than a predetermined first exhaust temperature YTH1 (for example, 250 ° C.) lower than the setting exhaust temperature of the heating power “3”? It is determined whether or not (S208). If TH ≧ YTH1, it is next determined whether or not the detected temperature TG of the temperature sensor 11 is equal to or higher than the second set temperature YTG2 (S209). The second set temperature YTG2 is set to a temperature detected by the temperature sensor 11 (for example, 810 ° C.) during combustion with the heating power “3” in a state where the article to be heated P is placed. When TG ≧ YTG2, a change in the detected temperature TG is monitored, and when the detected temperature TG is stabilized, the temperature is stored as an equilibrium temperature (S210).

  Thereafter, when the detected temperature TG is lowered from the equilibrium temperature by a predetermined temperature ΔT (for example, 20 ° C.) (S211), it is determined that the heated object P on the glass top plate 2 has been removed (no heated object), The flag FP is reset to “0” (S212), and even if the set thermal power is “4”, the operation is forcibly switched to the operation with the thermal power “3” to reduce the combustion amount (S213). Thereafter, if the detected temperature TG of the temperature sensor 11 does not rise until a predetermined time (for example, 30 seconds) elapses (S214), the combustion of the burner 4 is stopped (S215), and when the detected temperature TG rises, It is determined that the article P to be heated has been placed again, the flag FP is set to “1” (S216), and the operation is returned to the set heating power (S207). Note that the combustion may be continued with the heating power set to the minimum “1” without stopping the combustion in step S215.

  Also in the second embodiment, the life of the glass top plate 2 is determined by the same processing as the life determination processing shown in FIG. 7, and when the glass top plate 2 reaches the end of its service life, this is indicated. Notification is made so that it is possible to avoid such a problem that the glass top plate 2 expires during use and the glass top plate 2 is carelessly broken. Furthermore, also in the second embodiment, the temperature sensor 11 is arranged so as to reach the center of the combustion housing 3 from the rear of the combustion housing 3 in plan view, so that the object P to be heated is shifted on the glass top plate 2. Then, the object to be heated P comes off from the position directly above the temperature sensor 11, the reflected radiant heat from the bottom surface of the object to be heated P does not reach the temperature sensor 11, the temperature TG detected by the temperature sensor 11 decreases, and S211 in FIG. In this step, it is determined that there is no object to be heated. Therefore, a combustion amount reduction process at step S213 and a time measurement process for life determination at steps S104 and S105 in FIG. 7 are executed, and an unexpected situation due to a temperature rise due to the deviation of the object P to be heated is performed. Occurrence can be avoided.

  The full flat type gas stove in which the combustion casing 3 is provided with the radiator 5 in addition to the burner 4 in addition to the burner 4 has been described. However, the combustion exhaust gas is not supplied from the side of the combustion casing 3 without the radiator 5 being provided. The present invention can be similarly applied to a full flat type gas stove that is discharged. Further, in the above embodiment, the combustion amount is decreased when it is determined that there is no object to be heated. However, the combustion of the burner 4 may be stopped.

The perspective view of 1st Embodiment of this invention gas stove. Sectional drawing which shows the internal structure of 1st Embodiment. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. The figure which shows the arrangement position in the planar view of the temperature sensor in 1st Embodiment. The graph which shows the temperature measurement result of 1st Embodiment. The flowchart which shows the process including the presence or absence determination of the to-be-heated material in 1st Embodiment. The flowchart which shows the lifetime determination process of the glass top plate in 1st Embodiment. Sectional drawing which shows the internal structure of 2nd Embodiment. The graph which shows the temperature measurement result of 1st Embodiment. The flowchart which shows the process including the presence or absence determination of the to-be-heated material in 1st Embodiment.

Explanation of symbols

2 ... Glass top plate, 3 ... Combustion housing, 4 ... Burner, 4a ... Combustion surface, 8 ... Controller, 11 ... Temperature sensor, 14 ... Display lamp (notification means)

Claims (5)

A combustion housing whose upper surface is closed by the glass top plate is arranged under the glass top plate, and a surface combustion type burner is attached to the lower portion of the combustion housing with the combustion surface facing upward, and the upper surface of the glass top plate is mounted. In a gas stove that heats the object to be placed,
Equipped with a discriminating unit that discriminates the presence or absence of an object to be heated on the glass top plate. When it is determined that there is no object to be heated, the combustion of the burner is stopped or the heat reduction process is performed to reduce the amount of combustion A gas stove characterized by A combustion housing whose upper surface is closed by the glass top plate is arranged under the glass top plate, and a surface combustion type burner is attached to the lower portion of the combustion housing with the combustion surface facing upward, and the upper surface of the glass top plate is mounted. In a gas stove that heats the object to be placed,
Discriminating means for discriminating the presence or absence of an object to be heated on the glass top;
Accumulated by the amount of combustion in which the glass top plate is heated to a predetermined temperature or higher by burning of the burner in the state where it is determined that there is no object to be heated by the determination means and there is no object to be heated. A time measuring means for measuring the combustion time;
Life determination means for determining whether or not the glass top has reached the service life limit based on the cumulative combustion time measured by the time measuring means,
A gas stove comprising an informing means for informing when the glass top plate has reached the service life limit by the life judging means. The amount of combustion at which the glass top plate is heated to the first predetermined temperature by burning the burner in the absence of an object to be heated is defined as a first combustion amount, a second predetermined temperature higher than the first predetermined temperature. The amount of combustion that is heated up to the second combustion amount,
As the time measuring means, a first time measuring means for measuring the cumulative combustion time at the first combustion amount in a state in which it is determined that there is no object to be heated by the determining means, and a state in which it is determined that there is no object to be heated by the determining means. A second timing means for measuring the cumulative combustion time at the second combustion amount of
The lifetime determination means is configured such that the total time of the time obtained by multiplying the cumulative combustion time measured by the second measurement means by a predetermined coefficient and the cumulative combustion time measured by the first measurement means is the first time of the glass top plate. The gas stove according to claim 2, wherein the gas stove is configured to determine that the glass top plate has reached the service limit when the service life at a predetermined temperature of 1 is reached.   The said discrimination | determination means is comprised so that the presence or absence of to-be-heated material may be discriminate | determined based on the change of the temperature detected by the temperature sensor provided in the combustion housing. The gas stove described. 5. The temperature sensor is of a rod type with a cladding tube that covers a thermal element, and is disposed so as to reach the center of the combustion housing from the rear of the combustion housing in a plan view. The gas stove described in 1.

Images