JP3704665B2 - Series thermocouple - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a series thermocouple for generating a thermoelectromotive force of a flame in a gas combustor such as a gas table stove equipped with a blow-off safety device based on flame detection.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in a gas combustor such as a gas table stove, a safety device is provided that detects a thermoelectromotive force generated by the combustion heat of a flame by causing a thermocouple to face the flame in order to detect blowout of the flame. And when the detected thermoelectromotive force falls below a predetermined value, it is judged that it has blown out and the safety device is activated to cut off the fuel gas. In recent years, there is also a type of gas combustor that further includes a storage battery as a power source for combustion control or the like, and charges the storage battery using a thermoelectromotive force generated by the combustion heat of flame.
In a thermocouple used as a flame detection component of such a blow-off safety device of a gas combustor, a high electromotive force is desirable in order to stably operate a safety valve that shuts off fuel gas when blow-off occurs. Alternatively, it is necessary to obtain a high electromotive force in order to efficiently and easily charge the storage battery. Therefore, a thermocouple having a configuration in which a plurality of thermocouple elements are connected in series and integrated is used. For example, even if an electromotive force of 20 to 30 mV can be obtained with one thermocouple element, an electromotive force of 1.5 V can be obtained as a whole by integrating 50 thermocouple elements. Therefore, as shown in FIG. 6, the ends of two different types of metal wires 61, 62 are welded and connected in a zigzag shape to form a thermocouple assembly 60 in which a plurality of thermocouple elements 64 are connected. The thermocouple element 64 is connected to each other to form a hot junction portion 64a and a cold junction portion 64b, and the lead wires 60a and 60b are welded and connected to the head and the end, respectively. As shown in FIG. 7, the thermocouple assembly 60 thus produced is bundled with the thermocouple element 64, and then the cold junction part 64b is stored in the holder 75, and the remaining hot junction part 64a has a cylindrical shape. Cover 74. The cover 74 and the holder 75 are fitted.
The serial thermocouple 70 thus created is installed so as to face the flame 81a of the stove burner 81 as shown in FIG.
[0003]
[Problems to be solved by the invention]
However, since the series-type thermocouple 70 has a large number of thermocouple elements 64 bundled and covered with a cover 74, for example, when the burner 81 has a small heating power and the flame is small like the flame 81a, the high-temperature portion of the flame 81a Since the temperature of the low temperature portion is measured at the same time, about half of the thermocouple elements 64 are detached from the flame 81a when the temperature of the outer flame is measured. On the other hand, when the fire power of the burner 81 increases and the flame becomes as large as 81b, all of the thermocouple elements 64 enter the flame 81b, but this time it is affected by a low temperature internal flame. High electromotive force cannot be obtained.
In addition, since a large number of thermocouple elements 64 are provided and bundled and concentrated to measure the local temperature of the flame, the series thermocouple 70 as a whole cannot obtain sufficient heat from the flame.
In any case, sufficient electromotive force cannot be obtained due to this. Further, since the thermocouple elements 64 are closely integrated, the thermal response is poor and the rise and fall times of the electromotive force become long. In addition, the temperature at the temperature measurement point is not uniform, and the entire electromotive force is not stable.
An object of the present invention is to solve the above-mentioned problems, and to provide a series thermocouple capable of obtaining a stable high electromotive force and having a good thermal response.
[0004]
[Means for Solving the Problems]
The first series-type thermocouple of the present invention that solves the above-mentioned problems is a series-type that is generated by alternately joining two different metal wires in series and synthesizing the thermoelectromotive force of the joined plurality of contacts. In the thermocouple, the contact is housed in a ring-shaped holder and installed around the burner of the gas combustor. The holder is composed of inner and outer plates, and the holder is sandwiched and fixed between the plates. The gist of this is fixed .
[0006]
[Action]
The first series thermocouple of the present invention having the above-described configuration forms a thermocouple by alternately connecting two different metal wires in series, and takes out the thermoelectromotive force generated from each contact as a combined electromotive force. . Since these contact points are uniformly contained in a ring-shaped holder and installed around the burner of the gas combustor, a large amount of heat generated from the burner can be received efficiently.
Therefore, the response of the thermoelectromotive force generated from each contact point is good, and the rise time of the thermoelectromotive force is short. In addition, since it is installed evenly in a place where the temperature distribution of the burner is uniform, the overall thermoelectromotive force is also stabilized. Even if the temperature of the burner becomes unstable and the thermoelectromotive force generated from each contact fluctuates accordingly, the thermoelectromotive force is generated evenly from multiple contacts. Is stable with less fluctuation.
Furthermore, even if each contact receives only a small amount of heat, the thermocouple as a whole receives a large amount of heat and generates and generates a high thermoelectromotive force by synthesizing and extracting the electromotive force from the contacts connected in series. Can be made.
[0007]
Et al is, when accommodating the contact to the holder, by fixing by sandwiching the contacts between the plates of the inner and outer constituting the holder, secure the contacts to the holder. With this configuration, heat generated from the burner is immediately transmitted to the contacts. In addition, since only the contacts are fixed, the temperature difference between the hot junction and the cold junction can be greatly increased.
Therefore, the rise of the thermoelectromotive force is fast and the electromotive force itself obtained is large. That is, the thermal response is even better.
[0008]
【Example】
In order to further clarify the configuration and operation of the present invention described above, a preferred first embodiment of the series thermocouple of the present invention will be described below with reference to FIG. In addition, the detailed description of the part which overlaps with a prior art example about the basic structure of a thermocouple is abbreviate | omitted.
As described in the prior art (see FIGS. 6 and 7), the series thermocouple 10 is first welded at the ends of two different types of metal wires 61 and 62 and connected in a zigzag manner to form a hot junction 64a. And a cold junction part 64b are formed to make a thermocouple assembly 60 in which a plurality of thermocouple elements 64 are connected. The thermocouple element 64 is further connected to lead wires 60a and 60b at the beginning and end, respectively. In addition, the thermocouple assembly 60 is engraved on the surface in order to prevent the mutual contacts from being electrically short-circuited.
The thermocouple assembly 60 is formed in a ring shape having a slightly larger inner diameter than the holder inner plate 8 after the thermocouple elements 64 are uniformly arranged and attached to the outer periphery of the ring-shaped holder inner plate 8 having both ends expanded. By covering the holder outer plate 9 having a width capable of forming a cover while forming a ring shape from the outside, the whole can be accommodated as it is. The holder inner plate 8 and the holder outer plate 9 are aligned on both end surfaces, and the end surface of the holder inner plate 8 is bent and applied to the end surface of the holder outer plate 9 from the inside while the thermocouple element 64 is housed. At the same time, only the hot contact portion 64a is sandwiched between the holder inner plate 8 and the holder outer plate 9, and is closely attached and fixed.
The serial thermocouple 10 thus prepared is installed around the flame 1a of the stove burner 1 as shown in FIG. 2, and the hot junction 64a faces the flame 1a.
[0009]
The installation form will be described in detail.
The stove burner 1 is composed of a burner body 2 made of a cast material such as cast iron, and a substantially disc-shaped burner head 3 made of hot forging such as brass fitted to the burner body 2 from above. The The burner body 2 includes a mixing tube 4 that mixes the introduced fuel gas and primary air, and an annular mixing chamber 5 that is downstream of the mixing tube 4 and distributes the air-fuel mixture in an annular shape and ejects it from the gap with the burner head 3. Are united.
A cylindrical positioning guide 6 that also serves as a secondary air passage during combustion is provided at the center of the air-fuel mixture ejection side (the fitting side with the burner head 3) of the mixing chamber 5. The formed ring-shaped protrusion 7 is fitted while being positioned there. The air-fuel mixture sent from the mixing tube 4 to the mixing chamber 5 is ejected with a gap formed by the mating surface of the burner head 3 and the burner body 2 as a flame opening, thereby forming a ring-shaped flame 1a.
The series thermocouple 10 is fixed at a position where the hot junction 64a faces the flame 1a from below the flame 1a, and generates a thermoelectromotive force. The extinguishing safety device (not shown) is activated in accordance with the generated thermoelectromotive force.
[0010]
According to this series-type thermocouple 10, a large number of thermocouple elements 64 are connected in series, and the hot junction 64 a is sandwiched between the ring-shaped holder inner plate 8 and the holder outer plate 9 and caulked. Thus, it is uniformly packed around the ring shape and faces the entire flame 1a of the stove burner 1. As a result, it is possible to receive a large amount of heat generated from the flame 1a, and at the same time, heat generated from the flame 1a is immediately transmitted to the hot junction 64a.
Therefore, the time until the predetermined thermoelectromotive force is generated is shorter. That is, the responsiveness of the thermoelectromotive force generated from each of the hot junction portions 64a is good, and the electromotive force at which the rise of the thermoelectromotive force can be obtained quickly is high.
Moreover, since the uniform flame 1a temperature can be obtained in any hot junction 64a, the characteristics are very stable and the reliability is high. Even if the flame 1a fluctuates and the measured temperature of each hot junction 64a fluctuates accordingly, a large number of hot junctions 64a generate the thermoelectromotive force evenly. Therefore, the combined electromotive force is fluctuated. Disappears and stabilizes. Moreover, as a whole, a large amount of heat generated from the flame 1a can be received, and the thermoelectromotive force generated from a large number of hot contact portions 64a connected in series is synthesized and taken out. Even if the generated thermoelectromotive force is low, a high electromotive force can be obtained quickly as a whole.
[0011]
Next, a second embodiment will be described with reference to FIG.
The series thermocouple 30 has a configuration in which the thermocouple integrated body 60 is housed between the holder inner plate 38 and the holder outer plate 39 as in the first embodiment, but the way of housing is slightly different. First, after the thermocouple elements 64 are uniformly arranged and attached to the outer periphery of the ring-shaped holder inner plate 38 whose one end surface is expanded, the inner surface is slightly narrower than the holder inner plate 38 and the one end surface is narrowed down. The whole is accommodated in the ring-shaped holder outer plate 39 as it is. The holder inner plate 38 and the holder outer plate 39 are assembled by seam welding or caulking while fitting the both end faces and holding the thermocouple element 64. At this time, the hot junction 64 a and the cold junction 64 b are not sandwiched and fixed between the holder inner plate 8 and the holder outer plate 9.
The series thermocouple 30 thus produced is similarly installed around the flame 1a of the stove burner 1 as shown in FIG. 2, and has the same actions and effects as the first embodiment.
[0012]
Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and can of course be implemented in various modes without departing from the gist of the present invention. For example, as shown in FIG. 4, a parent / child burner 41 may be used instead of the stove burner 1, and the series thermocouple 10 or 30 may be placed around the flame 41a of the child burner 41b.
The parent-child burner 41 is a burner in which a small-burning child burner 41b is provided at the center of the large-burning parent burner 41c, and either or both are ignited according to the cooked product to adjust the heating power. is there. Even in such a parent-child burner 41, not only the parent burner 41c but also the child-burner 41b provided in the center, the series thermocouple 10 or 30 can be installed in the same manner, and the same operation and effect can be obtained. It is done.
In addition to the safety device, a storage battery (not shown) used for combustion control or the like may be provided, and the storage battery may be charged using the thermoelectromotive force generated by the series thermocouple 10 or 30. As described above, since the high electromotive force is obtained by synthesizing and taking out the thermoelectromotive force generated from the individual hot junction parts 64a, the storage battery can be easily charged. In this case, an easy-to-use combustion apparatus that does not require charging while having a storage battery can be configured.
In addition, as shown in FIG. 5, it may be installed in a pilot burner 51 for ignition of a water heater. This is a water heater provided with a bunsen burner 53 that burns a mixture of fuel gas and air, and is provided with a pilot burner 51 that burns a small amount of flame as normal fire for igniting the bunsen burner 53. A series thermocouple 10 or 30 is installed around. And when the thermoelectromotive force to detect falls, it is judged that the flame 51a of the pilot burner 51 blows off. Even in this case, a stable high electromotive force can be obtained, so that a reliable safety device can be configured.
[0013]
【The invention's effect】
As described in detail above, the first series thermocouple of the present invention has contacts connected in series in a ring-shaped holder and is uniformly installed around the burner of the gas combustor. The generated heat can be received in large quantities efficiently. Therefore, a high thermoelectromotive force can be generated, the rise time of the thermoelectromotive force is short, and the thermal response is good. Furthermore, the overall electromotive force is stable.
As a result, when used as a safety device that disappears, a stable and reliable safety device with good detection accuracy can be configured. Or when it uses for the combustion apparatus provided with the storage battery, since a thermoelectromotive force is high, since it can charge to a storage battery easily, the combustion apparatus with the ease of use that charge is unnecessary while comprising a storage battery can be comprised.
[0014]
Et al is, since the fixed contact between the plates which constitute the holder, thermal response is more favorable. As a result, it becomes a more reliable and high-performance series thermocouple and can be used for safety devices and combustion devices.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of a series thermocouple as a first embodiment.
FIG. 2 is a schematic view in which the series-type thermocouple of the first embodiment is installed in a stove burner.
FIG. 3 is a schematic configuration diagram of a series thermocouple as a second embodiment.
FIG. 4 is a schematic view in which the series thermocouple of the first or second embodiment is installed in a parent-child burner.
FIG. 5 is a schematic view in which a series thermocouple of the first or second embodiment is installed in a pilot burner.
FIG. 6 is a schematic configuration diagram of a series thermocouple element.
FIG. 7 is a schematic configuration diagram of a series thermocouple as a conventional example.
FIG. 8 is a schematic view in which a conventional series thermocouple is installed in a stove burner.
[Explanation of symbols]
1 Burner 1a Flame 2 Burner body 3 Burner head 4 Mixer tube 8 Holder inner plate 9 Holder outer plate 10, 30 Series thermocouple 41 Parent-child burner 41a Flame 41b Child burner 41c Parent burner 51 Pilot burner 51a Flame 60 Thermocouple integration Body 60a, 60b Lead wire 61, 62 Metal wire 64 Thermocouple element 64a Hot junction part 64b Cold junction part 70 Series thermocouple 74 Cover 75 Holder 81 Stove burner 81a, 81b Flame

Claims (1)

Two different metal wires are alternately connected in series,
In series thermocouples that are generated by combining the thermoelectric power of the connected multiple contacts,
The above contacts are placed in a ring-shaped holder and installed around the burner of the gas combustor.
The series thermocouple characterized in that the holder is composed of inner and outer plates, and the contacts are fixed to the holder by being sandwiched and fixed between the plates .

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