JPH0648274Y2 - Water heater safety device - Google Patents

Description

[Detailed Description of the Invention] [Field of Use and Outline of the Invention] The present invention relates to a safety device for a water heater, and more particularly to a safety device when a heat exchanger is damaged. In this case, the heat-sensitive means provided at a specific location can reliably detect the abnormal condition of the heat exchanger.Therefore, when the heat exchanger is damaged, the hot air from the body can be surely arranged. It is to be able to guide to the department.

[Prior Art and its Problems] A water heater has a structure in which a heat exchanger is housed in a casing, and in a water heater including a combustion device such as a gas water heater, a gas burner is provided below the heat exchanger. It is arranged.

Therefore, the heat exchanger is in a state of being heated by the gas burner when the device is used, and it is extremely long-term (long years).
In use, the heating can damage the heat exchanger. In order to ensure this safety, a safety device that stops the combustion of the gas burner when the heat exchanger is damaged has been adopted. Conventionally, this safety device has the configuration shown in FIG. 7 and FIG. Has been adopted.

Usually, in this type of device, the back side thereof faces the device installation wall surface, so damage to the back side of the heat exchanger (1) poses a serious problem. Therefore, as shown in FIG. 7, the heat-sensitive means (11) is arranged above the heat shield plate (13) arranged on the back side in the casing (10) surrounding the heat exchanger (1), 8th
As shown in the figure, the output from the heat sensitive means (11) is input to the control unit (31) of the safety device, and the solenoid valve (32) is operated by the output from the control unit (31) to operate the gas burner (2 2) is cut off or the operation of the appliance is stopped.

In this one, when the gas burner (2) is burning,
When the heat exchanger (1) is damaged, a predetermined signal output is generated from the heat sensing means (11), and this output is input to the control section (31), and the output thereof causes the solenoid valve (32) to operate and the gas burner ( The combustion of 2) stops. This ensures the safety of the device. The control device (3) including the control unit (31) is configured such that the operation of the appliance is controlled by a signal input from the operation unit, and the solenoid valve is also controlled to open and close by this control signal. To be done.

However, in this conventional device, when the heat exchanger (1) is damaged, the hot air blown from the damaged part does not reach the installation part of the heat sensitive means (11) depending on the damaged part of the heat exchanger. It is possible that the device does not work.

Since the heat shield plate (13) is made of a thin metal plate, the heat shield plate (13) is partially heated due to partial damage of the heat exchanger (1), and as a result, , As shown in FIG. 9, the heat shield plate (13) is curved due to thermal stress.
This is because the heat shield plate (13) may come into contact with the surface of the heat exchanger (1) and the passage of hot air to the heat sensitive means (11) may be blocked. In the heat exchanger (1), the water supply pipe (T) is usually located on the outer peripheral surface, but this water supply pipe is wound around the entire circumference of the body of the heat exchanger (1). Therefore, even if the heat shield plate (13) comes into contact with the surface of the water supply pipe (T) to form a gap with the surface of the body of the heat exchanger (1), the hot air passage has the contact portion. Shut off by.

In this way, if the hot air passage to the heat-sensitive means (11) is blocked, this cannot be detected despite the abnormal condition.

According to the present invention, the heat shield plate (13) is disposed between the heat exchanger (1) and the inner surface of the casing (10) that houses the heat exchanger (1) and the heat shield plate (13). A heat sensitive means (11) is provided in the space between the heat exchanger and the drive part of the safety device is operated by the output from the heat sensitive means (11) to damage a part of the heat exchanger (1). In order to ensure the safety when the heat exchanger (1) is damaged, the heat exchanger (1) is damaged when the heat exchanger (1) is stopped. To prevent the passage of hot air from the location to the heat sensitive means not to be blocked by the heat shield plate (13), and to prevent the heat shield plate from being thermally affected by the high temperature part of the heat exchanger (1) at normal times. Is the concrete issue.

* Regarding the invention of claim 1 [Technical means] The technical means of the present invention taken to solve the above-mentioned problem is "the surface of the heat exchanger (1) including the surface of the water supply pipe (T) or the heat shield plate". The surface of (13) is provided with a plurality of partial projections (4) and (4) that prevent these surfaces from contacting each other, and the height of these partial projections is determined by the surface of the heat exchanger (1) and the heat shield plate (13). It was set smaller than the distance from the surface. "

[Operation] The technical means of the present invention operates as follows.

Normally, the heat shield plate (13) and the surface of the heat exchanger (1) are opposed to each other with a constant gap.

A water heater has been used for a long time, and should it be a heat exchanger (1)
When the torso part is thermally deteriorated and partially damaged,
Hot air leaks from the damaged portion and heats the surface of the heat shield plate (13). As a result, thermal stress is generated in the heat shield plate (13) such that the heat shield plate (13) is curved. Since a plurality of partial projections (4) (4) that prevent these surfaces from contacting each other are provided, the surface of the heat exchanger (1) and the surface of the heat shield plate (13) even if some curvature occurs. Does not come into contact with.

Therefore, a constant gap is always formed between the heat shield plate (13) and the heat exchanger (1), and hot air reaches the heat sensing means (11). The heat sensitive means (1
When 1) detects the hot air, the safety device is activated by the output from the heat-sensitive means and the subsequent combustion is stopped.

The height of the partial protrusions (4) (4) is set smaller than the distance between the surface of the heat exchanger (1) and the surface of the heat shield plate (13). 2) and the surface of the heat exchanger (1) do not come in contact with each other via the partial protrusions (4), and thus the heat shield plate (13) can be prevented from being heated by heat conduction.

[Effects] The present invention having the above-described configuration has the following unique effects.

Even if the heat shield (13) is partially heated when the heat exchanger (1) is damaged and thermal stress is generated in the heat shield (13), a gap is always maintained between the heat shield and the heat exchanger (1). The hot air passage is not blocked because it is dripping. Therefore, the heat-sensitive means (11) can reliably detect the temperature in the abnormal state.

Further, in normal times, heat conduction from the heat exchanger (1) to the heat shield plate (13) does not occur, so that malfunction of the heat sensitive means (11) due to conduction heat from the heat exchanger (1) can be prevented.

* Concerning the invention of claim 2 The invention of claim 2 solves the same problem as that of the invention of claim 1 above, and by specifying the arrangement position of the partial protrusion (4), Even if the tip end side is always in contact with the heat exchanger side, the heat adverse effect from the heat exchanger (1) does not occur.

The means adopted for this purpose is "the surface of the water supply pipe (T) or the surface of the heat shield plate (13) facing the surface of the water supply pipe (T). Has been established ”.

According to this means, even if the heat shield plate (13) is curved to the surface side of the water supply pipe (T) by heating, there is a partial projection (4) at this portion, and the tip of this partial projection is in advance. In contact with the heat exchanger (1) side, a gap corresponding to the height of the partial projection (4) is formed between the heat shield plate (13) and the water supply pipe (T).

Even under the condition that the heat shield plate (13) and the water supply pipe (T) are in contact with each other through the partial protrusion (4) at normal times, the temperature of the water supply pipe (T) in the heat exchange state is relatively high. Since the temperature is low, the problem that the heat shield plate (13) is constantly heated from the heat exchanger (1) side due to heat transfer is eliminated, as in the case where the heat exchanger (1) is in contact with other parts. Therefore, there is no inconvenience that a large thermal stress is constantly applied to the heat shield plate.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 6.

First Embodiment The water heater of this embodiment is a push-burn type gas water heater and is a type of water heater that is installed on an indoor wall surface, and has a configuration similar to that of the conventional example described above. As shown in FIG. 2, a burner chamber (14) accommodating the gas burner (2) is arranged below the heat exchanger (1), and an air supply fan (F) is attached to the bottom of the burner chamber (14). In addition, a valve device (V) is continuously provided, these are housed in a casing (10), a gas circuit and a water supply circuit are introduced from below the casing (10), and an exhaust top () is provided above the heat exchanger (1). 12) is crowned.

As shown in FIGS. 1 and 2, the heat shield plate (13) is attached to the inner surface of the casing (10) so as to face substantially the entire rear surface of the heat exchanger (1).

In this embodiment, a thermal fuse (11a) is provided above the heat shield plate (13), and the thermal fuse (11a) is connected to the electric circuit of the solenoid valve (32) inserted in the circuit to the gas burner (2). It is inserted in series. The temperature fuse melts and cuts the electric circuit at a set temperature. In this embodiment, the temperature fuse (11a) functions as the heat-sensitive means (11) of the safety device and the control unit (3).
1) and the solenoid valve (32) functions as a drive unit.

The thermal fuse (11a) is attached and fixed to the heat shield plate (13) in such a manner that it is covered with an insulating cord, and hot air rising along the heat shield plate (13) is heated by the thermal fuse (11).
When it reaches part (a), this is detected and the electric circuit of the solenoid valve (32) is cut off.

The heat shield plate (13) is partially fixed to the inner surface of the casing (10), and the inner surface (the surface facing the surface of the heat exchanger (1)) has a large number of partial projections (4) (4). ) Is formed to project. The partial protrusions (4) and (4) are arranged so as to be located between the water supply pipes (T) and (T) of the heat exchanger (1), and the height of the partial protrusions (4) and (4) is normal. Is set to be slightly smaller than the distance between the body surface of the heat shield (13) and the surface of the heat shield (13), and the distance between the tip of the partial projection (4) and the surface of the heat exchanger (1) at this time is The distance between the surface of the heat shield plate (13) and the top of the water supply pipe (T) is set to be smaller. Therefore, even when the heat shield plate (13) is curved and comes closest to the heat exchanger (1) side, the surface of the heat shield plate (13) does not contact the water supply pipe (T). or,
The partial projections (4) are formed by bending a plate-like body into an L shape,
Since the plate-shaped upright portion (41) protruding from the heat shield plate (13) is arranged in a vertical posture, the partial projection (4) is formed.
Even when the tip of (4) is in contact with the body of the heat exchanger (1), a sufficient space is generated in the vicinity thereof and a hot air passage can be secured.

In the case of this embodiment, even if the heat exchanger (1) is partially damaged, and the surface of the heat shield plate is heated by the hot air from the damaged portion to bend the heat shield plate, the water supply pipe (T ) Will be blocked by the partial protrusions (4) (4).

When the heat exchanger (1) is partially damaged, the thermal fuse (11a) detects hot air rising in the gap between the heat shield plate (13) and the surface of the heat exchanger (1). As a result, the solenoid valve (32) is closed and combustion is stopped by the action described above.

* Second Embodiment In this embodiment, as shown in FIGS. 3 and 4, the heat shield plate (13) itself is partially bent to form a plurality of longitudinally extending ribs. Is a partial protrusion (4). In this thing, the height of the rib is set to the heat shield (13)
It is set slightly lower than the gap between the water supply pipe (T) of the heat exchanger (1). In this case as well, the same function as in the case of the first embodiment is performed, and the heat exchanger (1) is partially damaged,
Even if the heat shield (13) bends due to local heating,
A hot air passage will be secured. This is because even if the rib comes into contact with the water supply pipe (T), a space extending in the vertical direction is secured between the ribs.

In this embodiment, a fixed distance is provided between the upper end of the rib and the upper end of the heat shield plate (13), the thermal fuse (11a) is arranged on this flat surface, and the upper end of the heat shield plate is also provided. Since the rising pieces (16) that bend to the heat exchanger side are provided from both sides to almost the entire area of both side edges, even if hot air overflows anywhere on the entire inner surface of the heat shield plate (13), It will reach the fuse. At this time, the bent portion (17) at the upper end of the rising piece exerts the function of guiding hot air. The rising pieces on both sides also function as partial projections (4).

* Third Embodiment In this embodiment, as shown in FIG. 5 and FIG. 6, the water supply pipe (T) is provided with partial projections (4) and (4). The protruding metal fittings (40) are fitted to the water supply pipe (T) at predetermined intervals. The projection metal fitting (40) is entirely made of an elastic plate, and has a C-shaped portion (42) externally fitted to the cross section of the water supply pipe (T).
And a projecting piece (43) protruding from the top thereof,
When a plurality of the projection fittings (40) (40) are fitted to the water supply pipe (T) (T) at a position facing the heat shield plate (13), the water supply pipe (T) and the heat shield plate (13) are separated from each other. A space corresponding to the height of the protruding piece (43) can be secured between the surface and the surface.

The height of the protrusion (43) of this embodiment is set to a predetermined value by the relationship between the water supply pipe (T) and the heat shield (13), as in the case of the second embodiment. Normally, the water supply pipe (T) and the protruding piece (43) are not in contact with each other. In the case of the second and third embodiments, each partial protrusion (4) may be in contact with the other party. This is because the surface temperature of the water supply pipes (T) (T) is relatively low even during heat exchange.

It should be noted that the protrusion fitting (40) of this embodiment may be formed with an extension of the temperature fuse holding portion (49) as shown by the imaginary line in FIG. 6. In this case, the temperature fuse is not attached. It will be easy.

Further, as the heat-sensitive means, other types of heat-sensitive means can be adopted in addition to the thermal fuse, and as a safety device for realizing a safe operation, a thermocouple type, a system using a frame rod, or a heat-sensitive means A method of shutting off the power supply circuit to the water heater by the output and thereby closing the solenoid valve (32) can also be adopted.

[Brief description of drawings]

FIG. 1 is an explanatory view of a main part of a first embodiment of the present invention, FIG. 2 is an explanatory view of the whole thereof, and FIGS. 3 and 4 are explanatory views of a second embodiment, FIG. 5 and FIG. Is an explanatory view of the third embodiment, and FIGS. 7 to 9 are explanatory views of a conventional example. In the drawings, (1) ... Heat exchanger (10) ... Casing (13) ... Heat shield plate (T) …… Water supply pipe (4) …… Partial protrusion

Claims (2)

[Scope of utility model registration request] 1. A heat shield plate (13) is arranged between a heat exchanger (1) and an inner surface of a casing (10) for housing the heat exchanger (1), and the heat shield plate (13) and the heat exchanger. When a heat-sensitive means (11) is provided in the space between the heat-sensitive means (11) and the drive part of the safety device is operated by the output from the heat-sensitive means (11), and a part of the heat exchanger (1) is damaged. In a safety device for a water heater in which the operation of the combustion device is stopped, the surfaces of the heat exchanger (1) including the surface of the water supply pipe (T) or the surface of the heat shield plate (13) are in contact with each other. Multiple partial protrusions (4)
A water heater safety device in which (4) is provided and the height of the partial projection is set smaller than the distance between the surface of the heat exchanger (1) and the surface of the heat shield plate (13). 2. A heat shield plate (13) is disposed between the heat exchanger (1) and an inner surface of a casing (10) for housing the heat exchanger (1), and the heat shield plate (13) and the heat exchanger. When a heat-sensitive means (11) is provided in the space between the heat-sensitive means (11) and the drive part of the safety device is operated by the output from the heat-sensitive means (11), and a part of the heat exchanger (1) is damaged. In a safety device for a water heater in which the operation of the combustion device is stopped, a plurality of surfaces for preventing mutual contact with the surface of the water supply pipe (T) or the surface of the heat shield plate (13) facing the surface of the water supply pipe (T). Partial protrusions (4) (4)
Safety device for water heaters equipped with.