JP7111584B2 - heating cooker - Google Patents

Description

TECHNICAL FIELD The present invention relates to a heating cooker provided with a heating chamber for heating and cooking an object to be cooked. In particular, the present invention relates to a heating cooker equipped with a thermocouple for detecting combustion flame of a burner provided in a heating chamber.

Conventionally, there is a burner that heats the food to be cooked, and a thermocouple that is disposed near the flame hole of the burner and is heated by the combustion flame of the burner to output thermoelectromotive force, and heats the food to be cooked in the heating chamber. There is a heating cooker that heats and cooks. In this type of heating cooker, in order to prevent poor combustion due to misfire of the burner, when the thermoelectromotive force of the thermocouple falls below a predetermined misfire determination threshold, the on-off valve is closed to supply fuel gas to the burner. supply has been stopped.

JP 2014-206302 A

By the way, when the food to be cooked is being cooked in the heating chamber, for example, when the opening and closing door provided at the front opening of the heating chamber is opened and closed, low-temperature fresh air flows into the heating chamber from the outside and heats the food. The airflow in the warehouse changes. When the airflow changes due to such an external factor, the thermoelectromotive force of the thermocouple fluctuates, and the thermoelectromotive force drops below the misfire determination threshold. As a result, there is a problem that the burner is forcibly extinguished during cooking even though the burner is burning normally. On the other hand, placing the thermocouple too close to the burner port to increase the thermocouple output will overheat the thermocouple to a high temperature. As a result, the thermocouple is damaged, and even though the burner has misfired, the thermoelectromotive force does not drop below the misfire determination threshold for a long time, delaying the stoppage of the fuel gas supply to the burner. There is a problem.

The present invention has been made to solve the above problems, and an object of the present invention is to prevent damage to the thermocouple, accurately determine burner misfire, provide excellent cooking performance, and achieve high safety. To provide a heating cooker having

The present invention
A heating chamber that opens forward,
a burner for heating the food contained in the heating chamber;
A thermocouple that is exposed in the heating chamber so as to face the flame hole of the burner and detects the combustion flame formed in the flame hole;
The entire exposed part of the thermocouple exposed in the heating chamber is covered from the side opposite to the burner side, and extends further inside the heating chamber than the tip of the exposed part of the thermocouple in the extending direction of the thermocouple a first cover material to
a second cover material that covers the base of the exposed part of the thermocouple exposed in the heating chamber from the burner side,
The first cover member has at least a first opposing side wall portion provided facing the exposed portion of the thermocouple on the opposite side of the exposed portion of the thermocouple from the burner side,
The first opposing side wall portion is a heating cooker having a first through hole at a position facing an intermediate portion between the tip portion and the root portion of the exposed portion of the thermocouple.

According to the above heating cooker, the first cover material covers the entire exposed portion of the thermocouple exposed in the heating chamber from the side opposite to the burner side, and the thermocouple in the extending direction of the thermocouple Since the tip of the exposed portion of the thermocouple extends further inside the heating chamber than the tip of the exposed portion of the thermocouple, the tip of the exposed portion of the thermocouple, which is the heat-sensitive portion, is less susceptible to changes in the air current in the heating chamber. As a result, fluctuations in the thermoelectromotive force can be reduced, and the thermoelectromotive force can be prevented from falling below the misfire determination threshold when the burner is burning normally.

On the other hand, when the exposed portion of the thermocouple is covered with a large first cover material from the side opposite to the burner side, the first cover material is also heated to a high temperature by the burner. As a result, not only is the temperature of the exposed portion of the thermocouple likely to rise, but high-temperature hot air may remain between the first cover member and the burner, overheating the thermocouple. However, according to the above-described heating cooker, the second cover member covers the root portion of the exposed portion of the thermocouple exposed in the heating chamber from the burner side, so that the radiant heat from the burner can be reduced. In addition, hot air flowing from the burner side to the base of the exposed portion of the thermocouple can be shielded. As a result, the temperature of the root portion of the exposed portion of the thermocouple can be lowered during combustion of the burner, so that the temperature of the tip portion of the exposed portion of the thermocouple can be lowered by heat conduction. This can prevent damage to the thermocouple.

Further, according to the above-described heating cooker, the first cover member has at least the first opposing side wall portion provided facing the exposed portion of the thermocouple on the side opposite to the burner side of the exposed portion of the thermocouple. Since the first opposing side wall portion has the first through hole at a position facing the intermediate portion between the tip portion and the root portion of the exposed portion of the thermocouple, when the burner misfires, the first Hot air around the thermocouple covered with the cover material can be released from the first through hole, and the temperature of the tip of the exposed portion of the thermocouple can be lowered. As a result, when the burner misfires, hot air is less likely to stay in the first cover material, so the thermoelectromotive force can be reduced below the misfire determination threshold in a short period of time.

According to the heating cooker, the first through-hole is provided at a position facing the intermediate portion between the tip and the base of the exposed portion of the thermocouple, so that the hot air passes through the first through-hole. It is possible to reduce the influence on the tip of the exposed part of the thermocouple which is the heat sensitive part when passing through. Furthermore, the first through hole is provided at a position facing the intermediate portion, and the tip portion of the exposed portion of the thermocouple located on the inner side of the heating chamber than the first through hole faces the first opposing side wall portion. Therefore, even if the combustion state of other burners changes, the tip of the exposed portion of the thermocouple is not easily affected by changes in the air current inside the heating chamber. As a result, fluctuations in the thermoelectromotive force can be reduced, and it is possible to reliably prevent the thermoelectromotive force from dropping below the misfire determination threshold when the burner is burning normally.

Preferably, in the heating cooker,
The first cover member extends from both ends in the front-rear direction of the first opposing side wall portion toward the burner side, and is provided facing the exposed portion of the thermocouple on the front side of the heating chamber and the rear side of the heating chamber. having one front sidewall and a first rear sidewall;
The first forward sidewall and the first rearward sidewall are formed such that the gap between the first rearward sidewall and the burner is greater than that between the first forward sidewall and the burner.

According to the above-described heating cooker, the first cover member includes the first opposing side wall portion provided facing the exposed portion of the thermocouple on the opposite side of the exposed portion of the thermocouple from the burner side, and the first opposing side wall portion A first front side wall portion and a first rear side wall portion extending from both ends in the front-rear direction of the portion toward the burner side and facing the exposed portion of the thermocouple on the front side of the heating chamber and the rear side of the heating chamber. Therefore, even if the airflow inside the heating chamber changes due to an external factor, fluctuations in the thermoelectromotive force can be reliably reduced.

On the other hand, since the first cover member has the first facing side wall portion, the first front side wall portion, and the first rear side wall portion, the first cover member is heated to a high temperature and covered with the first cover member. Hot air tends to accumulate around the exposed portion of the thermocouple. Therefore, when the burner misfires, the thermoelectromotive force does not drop below the misfire determination threshold for a long period of time, which may delay the stoppage of fuel gas supply to the burner.

However, according to the heating cooker, the first front side wall and the first rear side wall have a gap between the first rear side wall and the burner larger than that between the first front side wall and the burner. Since it is formed to be large, heat transfer from the burner to the first cover member can be suppressed, and hot air can be released to the rear side of the heating chamber, so that the temperature of the thermocouple can be lowered. . As a result, when the burner misfires, hot air is less likely to stay in the first cover material, so the thermoelectromotive force can be reduced below the misfire determination threshold in a short period of time.

Preferably, in the heating cooker,
The second cover material includes a second opposing side wall portion provided facing the root portion of the exposed portion of the thermocouple on the burner side of the base portion of the exposed portion of the thermocouple, and a heating chamber inside the second opposing side wall portion. a second inner side wall portion extending from one side end toward the first opposite side wall portion of the first cover member and through which the thermocouple penetrates;
The second cover member is configured such that the front-rear ends of the second opposing side wall portion and the second inner side wall portion substantially abut against the inner surfaces of the first front side wall portion and the first rear side wall portion of the first cover member, respectively. , is disposed within the first cover material.

According to the above-described heating cooker, the second cover member has the second opposing side wall portion provided facing the root portion of the exposed portion of the thermocouple on the burner side of the root portion of the exposed portion of the thermocouple. , the radiant heat from the burner can be shielded by the second opposing side wall portion. In addition, the second cover member extends from the end of the second opposing side wall portion on the inner side of the heating chamber toward the first opposing side wall portion of the first cover member, and the second inner side wall through which the thermocouple penetrates. Since it has the portion, it is possible to shield hot air from the inside of the heating chamber toward the base of the exposed portion of the thermocouple. Further, in the second cover member, the front-rear ends of the second opposing side wall portion and the second inner side wall portion substantially abut against the inner surfaces of the first front side wall portion and the first rear side wall portion of the first cover member, respectively. Since it is arranged in the first cover material so as to be in contact with the thermocouple, it can shield the hot air flowing toward the base of the exposed part of the thermocouple through the gap between the first cover material and the second cover material. can be done. As a result, when the burner burns, the temperature at the base of the exposed portion of the thermocouple can be lowered, and the temperature at the tip of the thermocouple can be lowered by heat conduction. As a result, it is possible to reliably prevent damage to the thermocouple.

Preferably, in the heating cooker,
The second cover member is a second extended side wall portion extending inward from the heating chamber along the inner surface of the first facing side wall portion of the first cover member from the end portion of the second inner side wall portion on the side of the first cover member. has
The second extended side wall portion has a second through hole at a position facing the first through hole.

According to the above-described heating cooker, the second cover member extends from the end of the second inner side wall portion on the side of the first cover member toward the interior of the heating chamber along the inner surface of the first opposing side wall portion of the first cover member. It has a second extended side wall portion that extends, and the second extended side wall portion has a second through hole at a position facing the first through hole, so that the second through hole and the first through hole The hot air around the thermocouple covered with the first cover material can be released into the heating chamber through the .

Preferably, in the heating cooker,
The first cover material and the second cover material are separate members or integrated members.

By forming the first cover member and the second cover member from separate members, heat conduction from the first cover member to the second cover member can be reduced during combustion of the burner. In addition, by forming the first cover material and the second cover material from a member integrated with each other, manufacturing can be facilitated.

As described above, according to the present invention, it is possible to prevent the thermocouple from being damaged during combustion of the burner, and reduce the fluctuation of the thermoelectromotive force when the air flow in the heating chamber changes due to an external factor. Therefore, it is possible to prevent unnecessary interruption of cooking while the burner is burning normally. Further, according to the present invention, when the burner misfires, the thermoelectromotive force can be reduced below the misfire determination threshold in a short period of time. Therefore, according to the present invention, an erroneous determination can be prevented when the burner has not misfired, and the supply of fuel gas to the burner can be stopped in a short period of time when the burner has misfired. As a result, it is possible to provide a cooking device that has excellent cooking performance and high safety.

FIG. 1 is a schematic partially cutaway front view showing an example of a heating cooker according to an embodiment of the present invention. FIG. 2 is a schematic perspective view of essential parts of the heating chamber according to the embodiment of the present invention, viewed from the right side. FIG. 3 is a schematic perspective view of the essential parts of the heating chamber according to the embodiment of the present invention, viewed from the front and lower side. FIG. 4 is a schematic perspective view of essential parts showing a thermocouple, a first cover member and a second cover member attached to the cooking device according to the embodiment of the present invention. FIG. 5 is a graph showing fluctuations in the thermoelectromotive force of the thermocouple in the combustion state in the heating cooker according to the embodiment of the present invention and the comparative heating cooker. FIG. 6 is measurement data showing the temperature of each part of the thermocouple in the heating cooker according to the embodiment of the present invention and the comparative heating cooker. FIG. 7 is a graph showing fluctuations in the thermoelectromotive force of the thermocouple in the extinguished state in the heating cooker according to the embodiment of the present invention and the comparative heating cooker.

Hereinafter, the heating cooker according to the present embodiment will be specifically described with reference to the drawings.
FIG. 1 is a schematic partially cutaway front view showing an example of a heating cooker according to an embodiment of the present invention. The heating cooker 100 of the present embodiment is a commercial pottery cooker provided with a double-sided baking type heating chamber 2 that heats the food to be cooked from above and below by means of upper and lower burners 30 and 40 .

The heating cooker 100 includes an upper frame wall 101 provided with an exhaust port 110 for discharging hot air in the heating chamber 2 to the outside, left and right frame walls 102 and 103, a rear frame wall (not shown), and a lower frame wall. A substantially rectangular box-shaped cooker body 120 having a wall 104, upper and lower front frames 105 and 106, and left and right front frames 107 and 108; A heat insulating door 130 is provided. The heating chamber 2 accommodated in the cooker main body 120 has a top wall 21, left and right walls 22 and 23, a rear wall (not shown), and a bottom wall 24, and faces the food to be cooked. It has a substantially rectangular box shape with an opening 20 for loading and unloading. A lower flame burner knob 151 and upper flame burner knobs 152 and 153 are arranged in the operation portion on the right side of the heat insulating door 130 provided on the right front frame 108 . In this specification, the depth direction when viewing the cooker 100 from the front side where the heat shield door 130 is provided is referred to as the front-rear direction, the width direction is referred to as the left-right direction, and the height direction is referred to as the up-down direction.

Inside the heating chamber 2, a gridiron 9 on which the food to be cooked is placed is arranged. A pair of underfire burners 40 are arranged below the grill 9 over substantially the entire width of the heating chamber 2 in the left-right direction before and after heating the food to be cooked from below. Each underfire burner 40 has a burner pipe 41 extending left and right, and a red hot plate 42 heated by the burner pipe 41 between the burner pipe 41 and the grill 9 . Therefore, when the bottom burner 40 is ignited, a combustion flame is formed in the burner pipe 41 to heat the red hot plate 42 , and radiant heat and hot air are radiated upward from the heating chamber 2 . Although not shown, a gas pipe, an open/close electromagnetic valve, and the like are arranged in an internal space behind the right front frame 108 between the right wall 23 of the heating chamber 2 and the right frame wall 103 of the cooking device 100. In the lower region thereof, a lower pilot burner for transferring the pilot flame to the lower flame burner 40 for ignition and an ignition electrode for igniting the lower pilot burner. and are arranged. Thermocouples for detecting combustion flames formed in each bottom burner 40 are provided so as to penetrate the right wall 23 of the heating chamber 2 from the appliance installation portion and protrude inward of the heating chamber. .

Above the grill 9 in the heating chamber 2, over substantially the entire width of the heating chamber 2 in the left-right direction so as to face the burner opening (not shown) provided on the upper wall 21 of the heating chamber 2, A pair of top-fire burners 30 are arranged before and after heating the food to be cooked from above. The top-fire burner 30 is a surface-combustion ceramic burner with a large number of flame holes formed on its lower surface, and includes a burner body 31 and a planar heating plate 32 provided at the opening of the burner body 31 . Therefore, when the upper flame burner 30 is ignited, a combustion flame is formed on substantially the entire lower surface, and radiant heat and hot air are radiated downward from the heating chamber 2 .

FIG. 2 is a schematic perspective view of the essential part showing the vicinity of the right wall 23 of the top flame burner 30 viewed from the right side of the heating chamber 2, and FIG. It is a principal part schematic perspective view which shows right wall 23 vicinity. As shown in FIG. 2, an upper pilot burner 90 for transferring the pilot flame to the upper flame burner 30 and igniting the upper flame burner 30 and an upper pilot burner 90 An ignition electrode 91 for igniting 90 is provided. Although not shown, an opening/closing solenoid valve for supplying/stopping the fuel gas to the upper flame burner 30, an upper pilot solenoid valve for supplying/stopping the fuel gas to the upper pilot burner 90, and the like are arranged in the device installation portion. ing.

The right wall 23 of the heating chamber 2 below the right end of each upper flame burner 30 has a thermocouple insertion hole 26 for inserting the thermocouple 8 and a pilot flame penetration through which the flame hole of the upper pilot burner 90 faces. A port 27 and a locking through-hole 28 for locking a first cover member 5 (to be described later) are opened in this order from the front. When the upper pilot burner 90 is ignited, the pilot flame is ejected into the heating chamber 2 through the pilot flame through-hole 27, spreads to the upper flame burner 30, and the upper flame burner 30 is ignited.

As shown in FIGS. 2 to 4, the thermocouple 8 for detecting the combustion flame formed in the top flame burner 30 has approximately half of the tip portion side of the thermocouple 8 extending from the device installation portion to the thermocouple insertion port 26. and is exposed substantially horizontally to the inside of the heating chamber for a predetermined length (for example, about 30 mm). The tip 81 of the exposed portion of the thermocouple 8 exposed inside the heating chamber 2 faces the flame hole 35 of the top flame burner 30 near the right wall 23 of the heating chamber 2 . The thermocouple 8 is a sheath-type thermocouple enclosed in a sheath tube made of heat-resistant metal, and a substantially conical tip portion 81 constitutes a heat-sensitive portion. In the thermocouple 8, the thermocouple mounting portion 95 through which the rear end portion of the thermocouple 8 is inserted is screwed to the pedestal portion 29 provided on the upper portion of the right wall 23 of the heating chamber 2 in the apparatus installation portion with a screw P. is fixed by A wire 88 is connected to the rear end of the thermocouple 8, and the thermoelectromotive force generated by heating the thermocouple 8 by the combustion flame of the top-fire burner 30 is transmitted through the wire 88 to a controller (not shown). output to

A first cover member 5 made of a heat-resistant metal is attached to the inner surface of the right wall 23 of the heating chamber 2 to cover the entire exposed portion of the thermocouple 8 exposed inside the heating chamber 2 from below. When the first cover member 5 is attached to the inner surface of the right wall 23 of the heating chamber 2, the thermocouple 8 protruding inward from the right wall 23 of the heating chamber 2 is exposed. a first facing side wall portion 51 extending facing the lower portion of the portion; A first rear side wall portion 53 and a first front mounting portion extending forward from the base end of the first front side wall portion 52 on the right wall side of the heating chamber 2 along the inner surface of the right wall 23 of the heating chamber 2. 54 extends rearward across the adjacent pilot flame through-hole 27 from the upper edge of the first rear side wall portion 53 in the vicinity of the base end on the right wall side of the heating chamber 2, and further extends rearward from the rear end portion of the heating chamber. 2, and a first rear mounting portion 55 that is bent downward along the inner surface of the right wall 23 of No. 2. When the first cover member 5 is attached to the inner surface of the right wall 23 of the heating chamber 2, the first rear side wall portion 53 and the first rear attachment portion 55 are provided with the through hole 27 for the pilot flame and the engaging portion, respectively. Engagement portions 53a and 55a are provided so as to protrude from the through-hole 28 toward the outside of the heating chamber and into the device placement portion and be engaged therewith.

The first cover member 5 has a first front mounting portion 54 and a first rear mounting portion 55 arranged along the inner surface of the right wall 23 of the heating chamber 2 and attached to the right wall 23 of the heating chamber 2 on the side of the apparatus installation portion. It is fixed by screwing with a screw P from the outside. Therefore, when the first cover member 5 is attached to the inner surface of the right wall 23 of the heating chamber 2 so as to cover the exposed portion of the thermocouple 8 exposed in the heating chamber 2 from below, the exposed portion of the thermocouple 8 is , a first opposing side wall portion 51 facing downward of the exposed portion, a first front side wall portion 52 facing forward of the exposed portion of the thermocouple 8, and a first rear side wall portion facing rearward of the exposed portion of the thermocouple 8. It is accommodated without contact with these side walls 51 , 52 , 53 in an approximately gutter-shaped accommodating portion that is formed by 53 and is open to the top burner side and to the inside of the heating chamber on the left side.

The first opposing side wall portion 51 extends inward of the heating chamber by a predetermined length (for example, about 10 mm) beyond the projecting end of the tip portion 81 . The first opposing side wall portion 51 is an intermediate portion of the exposed portion of the thermocouple 8 between the tip portion 81 of the exposed portion of the thermocouple 8 and a second inner side wall portion 72 of the second cover member 7 described later. A first through hole 55 penetrating through the first opposing side wall portion 51 is provided at a position opposed to 82 . The first through hole 55 is provided with a width slightly smaller than the width of the first opposing side wall portion 51 in the front-rear direction and a predetermined length (for example, about 7 mm). Note that the first through hole 55 is an intermediate portion between the tip of the exposed portion of the thermocouple 8 which is the heat-sensitive portion and the root portion 83 of the exposed portion of the thermocouple 8 covered with the second cover material 5. It may be provided to face only a part of 82 .

When the first cover member 5 is attached to the inner surface of the right wall 23 of the heating chamber 2 , the upper edge of the first front side wall portion 52 and the first rear side wall portion 53 are positioned so that the upper edge of the top flame burner 30 The upper edge of the first rear side wall portion 53, which substantially contacts the lower surface and is located on the inner side of the heating chamber than the second inner side wall portion 72, is lower than the upper edge of the first front side wall portion 52 (for example, about 2 mm). ). Therefore, a larger gap is formed between the first rear side wall portion 53 and the lower surface of the top flame burner 30 than between the first front side wall portion 52 and the bottom surface of the top flame burner 30 .

A second cover member 7 made of a heat-resistant metal is arranged in the accommodation portion of the first cover member 5 for the thermocouple 8 . The second cover material 7 faces above the root portion 83 of the exposed portion of the thermocouple 8 located near the inner surface of the right wall 23 of the heating chamber 2 (for example, about 15 mm from the inner surface of the right wall 23 of the heating chamber 2). a second opposing side wall portion 71 extending in the direction in which the thermocouple 8 extends; and a second inner side wall portion 72 extending vertically toward the right peripheral edge of the first through hole 55, and a first opposite side wall portion extending from the lower end of the second inner side wall portion 72. and a second extended side wall portion 73 that extends along the inner surface of the heating chamber 51 to the end of the first opposing side wall portion 51 on the inner side of the heating chamber.

The second opposing side wall portion 71 and the second inner side wall portion 72 form a gap between the first cover member 5 and the second cover member 7 when the second cover member 7 is arranged inside the first cover member 5 . Both ends of the second opposing side wall portion 71 and the second inner side wall portion 72 in the front-rear direction are sized to contact the inner surfaces of the first front side wall portion 52 and the first rear side wall portion 53, respectively, so as not to form is set. Although not shown, an insertion hole for inserting the thermocouple 8 is formed in the upper, lower, and front-back direction of the second inner side wall portion 72 . The housing portion for the thermocouple 8 formed by the first cover member 5 extends through the insertion hole 72 toward the inside of the heating chamber. Therefore, when the thermocouple 8 is inserted through the insertion hole of the second inner side wall portion 72 of the second cover member 7 , the root portion 83 of the exposed portion of the thermocouple 8 is located between the right wall 23 of the heating chamber 2 and the first The periphery is defined by the first facing side wall portion 51, the first front side wall portion 52 and the first rear side wall portion 53 of the cover member 5 and the second facing side wall portion 71 and the second inner side wall portion 72 of the second cover member 7. It is arranged in a substantially rectangular box-shaped space defined from the storage portion of the thermocouple 8 on the inner side of the heating chamber in which the tip portion 81 of the exposed portion of the thermocouple 8 is stored.

The second cover member 7 is fixed to the first cover member 5 by spot welding the second extended side wall portion 73 to the first opposing side wall portion 51 . The second extended side wall portion 73 has a second through hole 75 at a position facing the first through hole 55 when the second cover member 7 is arranged in the accommodation portion of the first cover member 5 for the thermocouple 8 . has been established. The second through hole 75 has approximately the same size as the first through hole 55 . Therefore, the housing portions for the thermocouples 8 of the first cover member 5 on the inner side of the heating chamber on the left side of the second inner side wall portion 72 are not only on the top burner side and the inner side of the heating chamber, but also on the second inner side wall portion 72 . It communicates with the interior of the heating chamber 2 via the through hole 75 and the first through hole 55 .

Although not shown, the control device connected to thermocouple 8 via wiring 88 has a misfire determination circuit. After the top burner 30 is ignited, the misfire determination circuit forcibly closes the corresponding open/close solenoid valve when the thermoelectromotive force output from the thermocouple 8 becomes less than a predetermined misfire determination threshold. As a result, the supply of fuel gas to the top-fire burner 30 is stopped.

According to the present embodiment, the exposed portion of the thermocouple 8 protruding inward from the right wall 23, which is one of the constituent walls of the heating chamber 2, is located on the top burner side. is covered with a first cover member 5 having a first opposing side wall portion 51, a first front side wall portion 52, and a first rear side wall portion 53 from below on the opposite side, and the first cover member 5 is heated It extends inside the heating chamber beyond the tip 81 of the exposed portion of the thermocouple 8 exposed in the chamber 2 . Therefore, for example, when the heat shield door 130 is opened and closed, external low-temperature fresh air flows into the heating chamber 2, and even if the airflow inside the heating chamber 2 changes, it is covered by the first cover material 5. The tip 81 of the exposed portion of the thermocouple 8 is less susceptible to changes in air currents, and variations in thermoelectromotive force can be reliably reduced.

In addition, the first through hole 55 is provided at a position facing the intermediate portion 82 of the exposed portion of the thermocouple 8, and the exposed portion of the thermocouple 8 located on the inner side of the heating chamber than the first through hole 55 is provided. Since the tip portion 81 faces the first opposing side wall portion 51, the influence of the hot air on the tip portion 81, which is the heat sensitive portion, when passing through the second through hole 75 and the first through hole 55 can be reduced. can. Also, for example, when the bottom burner 40 is extinguished, the airflow in the heating chamber 2 changes, and the low-temperature hot air in the heating chamber 2 passes through the first through hole 55 and the second through hole 75 to the thermocouple 8 . Even if the air flows into the accommodation portion, the tip 81 of the exposed portion of the thermocouple 8 is not easily affected by changes in the air flow, and fluctuations in the thermoelectromotive force can be reliably reduced. As a result, when the top flame burner 30 is burning normally, even if the air flow in the heating chamber 2 changes due to the above external factors, the thermoelectromotive force is prevented from falling below the misfire determination threshold. can be prevented.

On the other hand, since the first cover member 5 has a first opposing side wall portion 51, a first front side wall portion 52, and a first rear side wall portion 53 that extend inward from the thermocouple 8, Hot air stays around the thermocouple 8 covered with the first cover material 5, and the first cover material 5 is heated to a high temperature. As a result, the exposed portions of the thermocouple 8 facing the first opposing side wall portion 51, the first front side wall portion 52, and the first rear side wall portion 53 may be overheated and the thermocouple 8 may be damaged.

However, according to the above-described embodiment, the second cover member 7 faces the base portion 83 of the exposed portion of the thermocouple 8 on the top burner side above the base portion 83 of the exposed portion of the thermocouple 8. Since the second opposing side wall portion 71 is provided on the side of the top flame burner 30, the second opposing side wall portion 71 can shield the radiant heat from the top flame burner 30, and the base of the exposed portion of the thermocouple 8 from the top flame burner side can be Hot air flow to portion 83 can be blocked. The second cover member 7 extends from the end of the second opposing side wall portion 71 on the inner side of the heating chamber toward the first opposing side wall portion 51 of the first cover member 5, and the thermocouple 8 penetrates it. Since the second inner side wall portion 72 is provided, it is possible to shield hot air from the inside of the heating chamber toward the root portion 83 of the exposed portion of the thermocouple 8 . Further, both ends of the second facing side wall portion 71 and the second inner side wall portion 72 in the front-rear direction are Since it is substantially in contact with the inner surfaces of the first front side wall portion 52 and the first rear side wall portion 53 , it is possible to reliably block the hot air flowing toward the root portion 83 of the exposed portion of the thermocouple 8 . As a result, when the top flame burner 30 burns, the temperature of the root portion 83 of the exposed portion of the thermocouple 8 can be lowered, and the temperature of the tip portion 81 of the exposed portion of the thermocouple 8 can be lowered by heat conduction. can. Thereby, damage to the thermocouple 8 can be prevented.

Further, according to the above embodiment, the first through hole 55 opened in the first opposing side wall portion 51 faces the intermediate portion 82 between the tip portion 81 and the root portion 83 of the exposed portion of the thermocouple 8. Since the second through hole 75 opened in the second extended side wall portion 73 faces the first through hole 55, the thermocouple 8 covered with the first cover material 5 The surrounding hot air can be quickly discharged into the heating chamber 2 through the second through holes 75 and the first through holes 55 . Further, the first front side wall portion 52 and the first rear side wall portion 53 are arranged such that the gap between the first rear side wall portion 53 and the top flame burner 30 is equal to that between the first front side wall portion 52 and the top flame burner 30 . , it is possible to suppress heat transfer from the top flame burner 30 to the first cover material 5, and to release hot air from the inside of the first cover material 5 to the rear side of the heating chamber. be able to. As a result, when the top flame burner 30 misfires, it is difficult for hot air to remain in the first cover member 5, so that the thermoelectromotive force can be reduced below the misfire determination threshold in a short period of time.

Further, according to the above embodiment, since the first cover member 5 and the second cover member 7 are formed from separate members, heat conduction from the first cover member 5 to the second cover member 7 can be reduced. can be done. As a result, the temperature of the root portion 83 of the exposed portion of the thermocouple 8 can be lowered during combustion of the top flame burner 30, and the temperature of the tip portion 81 of the exposed portion of the thermocouple 8 can be further lowered by heat conduction. can be done. As a result, damage to the thermocouple 8 can be reliably prevented.

FIG. 5 is a graph showing fluctuations in the thermoelectromotive force of the thermocouple in the combustion state of the rear top-firing burner 30 in the heating cooker of the present embodiment and the comparative heating cooker. In FIG. 5, (a) is a heating cooker having the first cover material 5 and the second cover material 7 of the present embodiment, (b) is not formed with the first through hole 55, Heat cooking for comparison in which the first facing side wall portion 51 has the first cover member formed only to the position facing the tip portion 81 of the exposed portion of the thermocouple 8, and the second cover member 7 is not provided. (c), the first through hole 55 is not formed, but the first opposing side wall portion 71 extends to the inner side of the heating chamber from the tip portion 81 of the exposed portion of the thermocouple 8. (d) shows that the first opposing side wall portion 51 is the tip portion 81 of the exposed portion of the thermocouple 8. The first cover member extends to the inner side of the heating chamber, but the first through hole is opened at a position facing the tip portion 81 of the exposed portion of the thermocouple 8, and the second cover It is a comparative heating cooker in which the material 7 is not provided. In addition, the first cover members of the heating cookers (b) to (d) for comparison are all provided with a first front side wall portion and a first rear side wall portion having the same height.

In the measurement of FIG. 5, in order to compare changes in the thermoelectromotive force of the thermocouple 8 that detects the combustion flame of the top-fire burner 30 when the airflow in the heating chamber 2 changes, in any cooking device, For 20 minutes from the start of ignition, the upper and lower burners 30, 40 are burned with a large flame with the heat shield door 130 closed, and for 20 to 25 minutes, the upper and lower burners are burned at the same thermal power with the heat shield door 130 open. Burners 30 and 40 are combusted. Also, for 25 to 30 minutes, the top flame burner 30 is burned with the same thermal power with the heat shield door 130 closed, but the bottom flame burner 40 is extinguished. The front top-fire burner 30 is extinguished, and only the rear top-fire burner 30 is burned with a large flame.

As shown in FIG. 5, in any heating cooker, when the heat shield door 130 is closed and all the upper and lower burners 30, 40 are stably burning, no large fluctuation in the thermoelectromotive force is observed. However, when the heat shield door 130 is opened and external low-temperature fresh air flows into the heating chamber 2, the airflow in the heating chamber 2 changes. Therefore, in the heating cooker (b) in which the first facing side wall portion of the first cover member extending to the inner side of the heating chamber is formed only up to the tip portion of the thermocouple 8, the thermoelectromotive force is greatly reduced ( 20 to 25 minutes thermoelectromotive force of the heating cooker (b)). On the other hand, in the heating cooker (a) of the present embodiment, even if the heat shield door 130 is opened while the top flame burner 30 is burning, the decrease in the thermoelectromotive force is small (heating cooker (a) 20 to 25 minutes of thermoelectric power). Generally, the misfire determination threshold value is set within a certain range in consideration of the tolerance of the thermocouple 8. However, it is preferable to set the misfire determination threshold value high in order to suppress leakage of unburned gas during combustion of the burner. Therefore, according to the present embodiment, even if the maximum value of the misfire determination threshold value is set to about 1.5 mV, for example, it is possible to reliably prevent an erroneous misfire determination when the heat shield door 130 is open.

In addition, in the heating cooker (d) having the first cover member provided with the through hole at the position facing the tip 81 of the exposed portion of the thermocouple 8, the opening of the heat shield door 130 causes a change in the air flow. However, if the combustion state of the other upper and lower burners 30, 40 changes, fluctuations in the thermoelectromotive force occur (heating cooker (d) heat electromotive force from 25 minutes to 35 minutes). power). By extinguishing the other upper and lower burners 30 and 40, this flows to the exposed tip end portion 81 of the thermocouple 8 through a through hole provided opposite to the exposed tip end portion 81 of the thermocouple 8. It is thought that this is because the temperature of the hot air changes. On the other hand, in the heating cooker (a) of the present embodiment, even if the other upper and lower burners 30 and 40 are extinguished, the fluctuation of the thermoelectromotive force output from the thermocouple 8 is small (heating cooker (a) a) thermoelectric power for 25 to 35 minutes). Therefore, according to the present embodiment, fluctuations in thermoelectromotive force due to changes in the combustion state of the other upper and lower burners 30 and 40 can also be reduced.

FIG. 6 shows temperature data of each portion of the exposed portion of the thermocouple 8 in the combustion state of the rear top-fire burner 30 in the heating cooker (a) of the present embodiment and the comparative heating cooker (c). be. Both temperatures are obtained when the upper and lower burners 30 and 40 are burned with a large flame while the heat shield door 130 is closed.

As shown in FIG. 5, the first opposing side wall portion extends to the inner side of the heating chamber from the tip portion 81 of the exposed portion of the thermocouple 8, but the second cover member 7 is not provided. In vessel (c), fluctuations in the thermoelectromotive force due to the opening of the heat shield door 130 and the like are small. Therefore, even in the heating cooker (c), it is possible to prevent erroneous determination of misfire when the top flame burner 30 is burning normally. However, as shown in FIG. 6, the temperature of the tip 81 of the exposed portion of the thermocouple 8 in the cooking device (c) is 704°C, and the temperature of the root portion 83 of the exposed portion of the thermocouple 8 is 553°C. On the other hand, in the heating cooker (a) of the present embodiment, the temperature of the tip portion 81 of the exposed portion of the thermocouple 8 is 599°C, and the temperature of the base portion 83 of the exposed portion of the thermocouple 8 is 405°C. be.

When the top flame burner 30 is burning, the first cover material 5 is also heated to a high temperature. Moreover, when the second cover member 7 is not formed, the entire exposed portion of the thermocouple 8 is directly heated by the radiant heat of the top flame burner 30 . Therefore, if the large first cover member 5 is provided below the exposed portion of the thermocouple 8, the temperature of the tip portion 81 of the exposed portion of the thermocouple 8 becomes higher, and the thermocouple 8 may be damaged. There is However, the temperature of the tip 81 of the exposed portion of the thermocouple 8 in the heating cooker (a) of the present embodiment is 105° C. lower than that of the comparative heating cooker (c). This is the second This is because the cover material 7 lowers the temperature of the exposed root portion 83 of the thermocouple 8 , and the thermal conduction of the cover material 7 can lower the temperature of the exposed tip portion 81 of the thermocouple 8 .

FIG. 7 is a graph showing fluctuations in the thermoelectromotive force of the thermocouple 8 when the top flame burner 30 is extinguished in the heating cooker (a) of the present embodiment and the comparative heating cooker (c). . As shown in FIG. 7, the thermoelectromotive force when the top flame burner 30 is extinguished in the heating cooker (a) of the present embodiment decreases more rapidly than that of the comparative heating cooker (c). do. When the exposed portion of the thermocouple 8 is covered from below with a first cover material in which a through hole is not formed, as in the cooking device (c), even if the top flame burner 30 misfires, the first cover material Hot air stays inside, and the temperature of the tip of the exposed portion of the thermocouple 8 does not easily drop. Therefore, it takes a long time for the thermoelectromotive force to drop below the misfire determination threshold. On the other hand, in the cooking device (a) of the present embodiment, when the top burner 30 misfires, the hot air around the thermocouple 8 covered with the first cover material 5 is transferred to the second through hole 75. And it can be discharged into the heating chamber 2 from the first through hole 55 and the gap between the top burner 30 and the first rear side wall portion 53 . Therefore, according to the present embodiment, when the minimum value of the misfire determination threshold value is set low, the on-off solenoid valve is closed more quickly than in the comparative cooking device (c), and the misfire occurs in a short time. The supply of fuel gas to the top flame burner 30 can be stopped.

As described above, according to the present embodiment, while the top flame burner 30 is burning, damage to the thermocouple 8 is prevented, and the thermoelectromotive force caused by changes in the airflow in the heating chamber 2 due to external factors is reduced. Since the fluctuation can be reduced, it is possible to prevent unnecessary interruption of cooking when the top-fire burner 30 is burning normally. Further, according to the present embodiment, when the top burner 30 misfires, the thermoelectromotive force can be reduced below the misfire determination threshold in a short period of time. Therefore, according to the present embodiment, it is possible to prevent erroneous determination when the top flame burner 30 has not misfired, and when the top flame burner 30 has misfired, fuel can be supplied to the top flame burner 30 in a short time. Gas supply can be stopped. As a result, it is possible to provide a cooking device that has excellent cooking performance and high safety.

(Other embodiments)
(1) In the above embodiment, the thermocouple for detecting the combustion flame formed in the flame hole of the top burner is covered from above and below by the first cover member and the second cover member. However, the thermocouple for detecting the combustion flame formed in the flame hole of the bottom burner may be covered from above and below with the first cover material and the second cover material which are turned upside down. Also, the top burner may be formed from the left and right walls of the heating chamber to the upper wall of the heating chamber.
(2) In the above embodiment, the thermocouple protrudes substantially horizontally into the heating chamber from the constituent wall of the heating chamber. However, depending on the configuration of the burner, it may be projected into the heating chamber at an angle from the wall constituting the heating chamber.
(3) In the above embodiment, the first cover member and the second cover member are separate members. However, for ease of manufacture, the first cover member and the second cover member may be configured as an integrated member.
(4) In the above embodiment, the second cover member having the second extended side wall portion is used. However, a second covering without the second extended sidewall may be used. In this case, it is not necessary to provide the second through hole opened in the second extended side wall portion.

2 Heating chamber 30 Top flame burner 8 Thermocouple 5 First cover member 51 First opposing side wall portion 52 First front side wall portion 53 First rear side wall portion 55 First through hole 7 Second cover member 71 Second opposing side wall portion 72 Second inner side wall portion 75 Second through hole 100 Heating cooker

Claims (5)

A heating chamber that opens forward,
a burner for heating the food contained in the heating chamber;
A thermocouple that is exposed in the heating chamber so as to face the flame hole of the burner and detects the combustion flame formed in the flame hole;
The entire exposed part of the thermocouple exposed in the heating chamber is covered from the side opposite to the burner side, and extends further inside the heating chamber than the tip of the exposed part of the thermocouple in the extending direction of the thermocouple a first cover material to
a second cover material that covers the base of the exposed part of the thermocouple exposed in the heating chamber from the burner side,
The first cover member has at least a first opposing side wall portion provided facing the exposed portion of the thermocouple on the opposite side of the exposed portion of the thermocouple from the burner side,
The heating cooker, wherein the first opposing side wall portion has a first through hole at a position facing an intermediate portion between the tip portion and the root portion of the exposed portion of the thermocouple. In the heating cooker according to claim 1,
The first cover member extends from both ends in the front-rear direction of the first opposing side wall portion toward the burner side, and is provided facing the exposed portion of the thermocouple on the front side of the heating chamber and the rear side of the heating chamber. having one front sidewall and a first rear sidewall;
The first front side wall and the first rear side wall are formed such that the gap between the first rear side wall and the burner is larger than the gap between the first front side wall and the burner. vessel. In the heating cooker according to claim 1 or 2,
The second cover material includes a second opposing side wall portion provided facing the root portion of the exposed portion of the thermocouple on the burner side of the base portion of the exposed portion of the thermocouple, and a heating chamber inside the second opposing side wall portion. a second inner side wall portion extending from one side end toward the first opposite side wall portion of the first cover member and through which the thermocouple penetrates;
The second cover member is configured such that the front-rear ends of the second opposing side wall portion and the second inner side wall portion substantially abut against the inner surfaces of the first front side wall portion and the first rear side wall portion of the first cover member, respectively. and a heating cooker disposed within the first cover material. In the heating cooker according to claim 3,
The second cover member is a second extended side wall portion extending inward from the heating chamber along the inner surface of the first facing side wall portion of the first cover member from the end portion of the second inner side wall portion on the side of the first cover member. has
The cooking device, wherein the second extended side wall portion has a second through hole at a position facing the first through hole. In the heat cooker according to any one of claims 1 to 4,
The first cover material and the second cover material are separate members or integrated members in the heating cooker.

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