JPH04155155A - Safety device for overheat of hot water-supplying heater - Google Patents

Abstract

PURPOSE:To prevent the occurrence of a fire or the burst of a water pipe by quickly sensing the overheat of a heat-exchanging boiler, by a method wherein a heat-receiving member for sensing the heat radiated from the heat-exchanging boiler is arranged at a clearance in a hot water-supplying heater main body, and when the heat-receiving member is heated at a definite temperature or higher, a gas cutoff valve is actuated. CONSTITUTION:As a heat-receiving member, a heat-sensing box 11 is arranged at a clearance 7 in a hot water-supplying heater main body 1, and as a switching means for actuating a gas cutoff valve 10, a microswitch 12 is provided in this heat-sensing box 11. The microswitch 12 is connected to an electric source part and the gas cutoff valve 10 through a lead wire 12b, and when the heat-sensing box 11 is heated and expanded, the microswitch 12 actuates and outputs an ON signal to the gas cutoff valve 10. The gas cutoff valve 10 is a solenoid valve, is provided on a gas pipe line for supplying a gas to a burner 4, is actuated by an output signal from the microswitch 12 and cuts off the supply of the gas. When the hot watersupplying heater main body 1 is heated abnormally at high temperature, the title device stops the combustion of the burner, and hence a danger that a wall surface 8 is burned by the overheat of an outer board 6 or a water pipe 3 is burst is prevented.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to water heaters such as water heaters and bathtubs, and in particular, the present invention relates to water heaters such as water heaters and bath kettles, and in particular, to water heaters that have a function of preventing overheating that occurs when a heat exchanger body is damaged. Regarding overheating safety devices for water heaters.

(Prior Art) Gas-supplied water heaters, such as water heaters and bathtubs, generally have a water heater main body (1) having the structure shown in FIGS. 5 and 6.
It is configured with. This water heater main body (1) consists of a heat exchange can (2), a wood pipe (3), a burner (4), an intake fan [5], etc., and these are covered with an exterior plate (6). The heat exchange can body (2) has a substantially rectangular shape, and is provided with an exhaust pipe (2a) at the upper part, and a case (2b) connected to the lower part. In this case (2b), the burner (4) is housed, and an intake fan (5) that supplies air for combustion to the lower side is provided. The water pipes (3) are wound around the upper side of the heat exchange can body (2) at appropriate intervals, with the water inlet side (3a) serving as the water supply valve and the hot water supply side (3b) serving as the hot water supply valve. are connected to each.

The exterior plate (6) is arranged so as to cover the outer periphery of the heat exchange can body (2) other than the lower side, and is provided on the front surface (2c
), a gap (7) is formed between the rear surface and both left and right side surfaces (2e) and (2f) and the exterior plate (6). Note that the exterior plate (6) on the back side (2d) serves as a mounting surface to a wall surface (8) or the like.

The water heater main body (1) configured in this way has 1
An overheat safety device is usually provided. This overheating safety device is intended for long-term use of the water heater, and high heat is radiated to the exterior plate (6) when a hole opens due to deterioration of the heat exchanger body (2).

In order to prevent the danger of burning out the wall surface (8) to which the water heater body (1) is attached, a temperature fuse (9) that melts when heated above a predetermined temperature is usually used. As shown in FIG. 6, a plurality of temperature fuses (9) are arranged at appropriate intervals around the outer periphery of the heat exchanger body (2), and each lead wire (9a) is connected to a power supply section (not shown) and It is connected to a gas cutoff valve (10) that cuts off gas supply. As a result, the heat exchanger body (2) overheats and the gap (7) reaches an abnormally high temperature, which causes it to melt and melt, activating the gas cutoff valve (10) and stopping the combustion of the burner (1). It is supposed to stop.

(Problem to be solved by the invention) However, this type of overheating safety device is
are dotted around the outer periphery of the heat exchanger body (2), so there is no possibility that the holes in the heat exchanger body (2) are located farther than the temperature fuse (9) or the holes are small. If so, the temperature fuse (9) may not be directly exposed to high heat. As a result, the heat exchanger body (2) overheats and reaches a considerably high temperature, causing the temperature fuse (9) to melt, causing burnout to the wall (8) to which the water heater body (1) is attached, and damage to the wood pipes ( 3) There was a risk of bursting due to high temperature heating.6 The present invention was made in view of the above problems.

The object of the present invention is to provide an overheating safety device for a water heater that can quickly detect overheating of a heat exchanger body and prevent dangers such as fire outbreak and wood pipe bursting.

(Means for Solving the Problems) In order to achieve the above object, the overheating safety device for a water heater according to the present invention is provided. A heat receiving member that senses the radiant heat from the heat exchanger body is interposed in the gap, and when this heat receiving member is heated to a predetermined temperature or higher, an operation signal is sent to a gas cutoff valve that cuts off the gas supply to the burner. The device is provided with a switch means for outputting.

(Function) According to the above configuration, when high heat is radiated to the exterior plate side when a hole is formed due to deterioration of the heat exchange can, the heat receiving member interposed in the gap receives the high heat and is heated. When the heat receiving member reaches a predetermined temperature or higher, the switch means outputs an operation signal to the gas cutoff valve, which cuts off the gas supply and stops combustion of the burner.

(Example) Hereinafter, one embodiment of the present invention will be described based on the drawings.

FIG. 1 is a longitudinal cross-sectional view of the back side of an overheating safety device for a water heater according to the present invention, and FIG. 2 is a side view of the same.

This overheating safety device for water heaters includes a heat-sensitive box (11) disposed as a heat-receiving member in the gap (7) of the water heater body (1) shown in FIGS. 5 and 6.
) is provided with a microswitch (12) as a switch means for operating the gas cutoff valve (10).

The others are different from the conventional example, and therefore, detailed explanation will be omitted.

The heat-sensitive box (11) is formed to have an area approximately equal to the front surface (2c) or back surface (2d) of the upper side of the heat exchange can body (2), and contains thermowax as an expansion material that expands when heated. is filled.

A concave cutout (lla) is formed at one end of the heat-sensitive box (11), and an extension piece (llb) is formed at one end of the heat-sensitive box (11).
is provided. An accordion-shaped bellows (llc) to which a rod (lid) is fixed is integrally formed in the cutout (lla).A microswitch (12) is provided in the extension piece (llb) to control its movable The part (12) is attached with the part (a) facing the rod (lid) side.

This heat-sensitive box (11) is held so as to be interposed in a planar manner in the upper gap (7) on the back (2d) side of the heat exchanger body (2), which is most easily damaged due to deterioration, and is The switch (12) is arranged in the gap (7) on the right side (2f). Furthermore, this microswitch (12) is connected to a power supply unit (not shown) and a gas shielding well (10).
) through lead wires (12b), and when the heat-sensitive box (11) is heated and expanded, it is activated and outputs an ON signal to the gas cutoff valve (10). Note that this gas cutoff valve (10) is a solenoid valve,
It is installed in a gas pipeline that supplies gas to the burner (4), and is activated in response to an output signal from a microswitch (12) to cut off the gas supply.

However, the above-mentioned overheating safety device for water heaters is
1) When the temperature reaches an abnormally high temperature, it is possible to immediately stop combustion and avoid the occurrence of danger. For example, if this water heater has been used for a long period of time and the heat exchange can body (2) has deteriorated, there is damage such as a hole in a part of the back side (2d) of the can body (2). , the gap (7) on the back side (2d) becomes abnormally high temperature due to the flame being radiated from this hole. At this time, high-temperature radiant heat is transferred to the back of the heat exchanger body (2) (
2d) Heat is received by a part of the planar heat-sensitive box (11) that covers the whole. Then, this thermal box (1
1) starts to expand even when the - part is heated, so
The bellows (llc) is compressed and contracted. Therefore, the rod (lid) moves and the micro switch (1
2) Press the movable part (12a) to turn it on. Then, the gas cutoff valve (10) is activated from the microswitch (12).
), an ON signal is output to this gas cutoff valve (10
) is cut off. As a result, combustion in the burner (4) is stopped, and the temperature rise in the heat exchanger body (2) is suppressed, and the wall surface (8) is burnt due to overheating of the exterior plate (6), and the
This prevents the risk of the device bursting.

Note that the heat-sensitive box (11) is not limited to being held in the gap (7) on the back (2d) side, but can also be placed in the gap (7) on the front (2c), both sides (2e), (2f), etc. You may. Alternatively, the outer periphery of the heat exchange can (2) may be covered with one heat-sensitive box (11) and held in the gap (7).

FIG. 3 is a vertical sectional view on the rear side showing another embodiment of the overheating safety device for a water heater, and FIG. 4 is a side view of the same.

The overheating safety device for a water heater according to this embodiment uses a heat transfer plate (13) as a heat receiving member, and a bimetal switch (14).
) is configured to shut off the gas cutoff valve (10). The rest is the same as the above embodiment, so detailed explanation will be omitted.

That is, the heat exchanger plate (13) is made of a metal material having an elongated strip shape and has excellent heat conductivity, and has a width between the width of the heat exchanger body (2) and the space between the paths.
It is formed to a length of . A plurality of sheets are arranged vertically between the main pipes (3) in the gap (7) on the back surface (2d) side of the heat exchange can body (2).

In addition, the bimetal switch (14) is connected to each heat exchanger plate (13).
), and when the heat exchanger plate (13) is installed, it is located in the gap (7) on the right side surface (2f). The bimetal switches (14) are connected in parallel through lead wires (14a).
14a) is connected to the power source and the gas cutoff valve (10), and when the heat transfer plate (13) is heated and the bimetal switch (14) is activated, it outputs an ON signal to the gas cutoff valve (10). It is supposed to be done.

According to the above configuration, when the water heater body (1) becomes abnormally high temperature due to damage such as a hole in a part of the heat exchange can (2), the heat exchanger plate (13) receives this radiant heat. ) is heated. In other words, since the heat exchanger plate (13) is arranged planarly in the gap (7), the hole may be small or the heat exchanger plate (13)
) Even if there is a hole between the holes, the radiant heat can be received with almost no leakage. This allows bimetallic switches (
14) operates quickly to close the gas shut-off valve (10).
An N signal is output. Then, the gas cutoff valve (10) cuts off the gas supply and stops the combustion of the burner (4), thereby preventing the risk of fire or the like.

The heat exchanger plate (13) is not limited to the back surface (2d) of the heat exchanger body (2), but may be provided in the gap (7) on the front surface (2C) side, or on one surface (2e), (2f). ) may be provided in the gap (7).

In addition, the bimetal switch (14) has a heat exchanger plate (13)
However, if there is space for installation in the gap (7), it may be fixed to the center of each heat exchanger plate (13).

(Effects of the Invention) As explained above, the present invention provides a heat receiving member that senses radiant heat from the heat exchanger body in the gap of the water heater body, and when the heat receiving member is heated to a predetermined temperature or higher, Since the gas cutoff valve is activated, when high heat is radiated to the exterior plate side due to deterioration of the heat exchange can and a hole is formed, the heat receiving member receives high heat and the heat exchange can is damaged. It can quickly detect overheating and prevent dangers such as fires and wood pipe bursts.

[Brief explanation of drawings]

1 to 4 show embodiments of the present invention, and FIG. 1 is a vertical sectional view on the rear side of the overheating safety device for a water heater according to the present invention,
FIG. 2 is a side view of the same, FIG. 3 is a longitudinal sectional view on the rear side showing another embodiment, FIG. 4 is a side view of the same, and FIG. FIG. 6 is a side view of the same. (1): Water heater body, (2): Heat exchange can body, (3): Wood pipe, (4): Burner, (7): Gap, (10): Gas cutoff valve, (11): Thermal box, (12): Micro switch, (13): Heat transfer plate, (14): Bimetal switch.

Claims (3)

[Claims] (1) A heat receiving member that senses the radiant heat from the heat exchange can is interposed in the gap between the exterior plate of the water heater body and the heat exchange can with water pipes arranged on the outer periphery. An overheating safety device for a water heater, comprising a switch means for outputting an operating signal to a gas cutoff valve that cuts off gas supply to a burner when the burner is heated to a predetermined temperature or higher. (2) The overheat safety device for a water heater according to claim 1, wherein a heat receiving member is disposed in a planar manner in at least the gap on the back side of the heat exchange can. (3) The overheating safety device for a water heater according to claim 1, wherein the heat receiving member is made of heat transfer plates, and a plurality of plates are arranged in a row in a gap around the heat exchange can.