JP3691140B2 - Water heater safety device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water heater having a water pressure responsive gas valve, and more particularly to a safety device for a water heater having an ignition device.
[0002]
[Prior art]
In a water heater equipped with an ignition device, the type in which the water circuit is opened in conjunction with the ignition operation and the gas burner is in a combustion state, or the ignition operation is ignited only after the ignition is performed, In some cases, when the water circuit is opened by another operation, the gas burner is brought into an operating state. In any water heater, a water pressure responsive gas valve is employed to open the water circuit and simultaneously open the main gas circuit.
This water pressure responsive gas valve opens the gas valve according to the change in water pressure when the water circuit is opened and the circuit to the heat exchanger communicates. Usually, the water circuit is opened by a diaphragm. A diaphragm chamber divided into a second chamber and a first chamber is formed, and the diaphragm is moved to the second chamber side as the pressure in the first chamber is increased when the water circuit is opened, and the main gas is generated by this moving force. The gas valve inserted in the circuit is opened. Therefore, when the water circuit to the heat exchanger communicates, the main gas circuit to the gas burner corresponding to the heat exchanger is automatically opened, and the ignition device that operates at this time or the seed ignition system In this case, the gas burner is brought into a combustion state by the already ignited seed fire, and the heat exchange operation is performed.
[0003]
[Problems to be solved by the invention]
However, in winter and the like, when the water in the first chamber of the diaphragm chamber freezes and the volume of this portion increases, the diaphragm moves to the second chamber side and the gas valve of the water pressure responsive gas valve opens. Therefore, if the ignition operation is performed in this state, the gas burner may be in a combustion state even though the water circuit to the heat exchanger is shut off due to the freezing of the first chamber. In other words, there may be an empty state.
[0004]
It is an object of the present invention to surely prevent the disadvantage that the watering state is caused when the water circuit portion of the water pressure responsive gas valve of a water heater provided with an ignition device is frozen. It is another object of the present invention to make it possible to smoothly and reliably execute the operation for preventing the air blow.
[0007]
[Means for Solving the Problems]
About Claim 1 The solution means of the invention of Claim 1 taken in order to solve the above-mentioned problem is: “An ignition device (2) for igniting a gas burner in response to an ignition operation, and a response to the ignition operation”. A main valve that opens the gas circuit to the gas burner, and a water pressure responsive gas valve that opens and closes the gas valve (14) of the gas circuit in response to the opening and closing of the water circuit. An open water heater,
The main valve is provided in series with the gas valve (14) in the gas circuit, and the ignition device (2) is in an operating state when the movable shaft (22) is advanced by operation of the operation unit (21). And
The water pressure responsive gas valve divides the diaphragm chamber (D) into a first chamber (11) connected to the water circuit and a second chamber (12) side, and the first chamber when the water circuit is opened. A diaphragm (1) for opening the gas valve (14) in conjunction with movement toward the second chamber (12) accompanying a change in pressure on the (11) side, and the diaphragm (1) and the gas valve ( 14), the gas valve (14) is opened by the movement of the diaphragm (1) to the second chamber (12) side and the spring is forced to the first chamber (11) side. With an interlocking mechanism with a restoring force,
A movable plate that is linked to the diaphragm (1) and moves between a projecting position where one end projects into the advancement region of the movable shaft (22) and prevents the advancement of the movable shaft (22) and a retracted position retracted from the position. (36)
The movable plate (36) is biased in the protruding direction by a spring (38),
The movable plate (36) is driven in the protruding direction by the urging force of the spring (38) when the diaphragm (1) moves toward the second chamber (12), and the first chamber (1) of the diaphragm (1) ( 11) When moving to the side, the interlocking mechanism is retracted by the forced return force of the interlocking mechanism,
The interlocking mechanism has a shaft portion connecting the gas valve (14) and the diaphragm (1), and the shaft portion has one end of a spring (17) for urging the diaphragm (1) toward the first chamber (11). A spring receiver (18) is provided to support the shaft, and the spring receiver (18) is provided on the shaft portion so as to be movable in the axial direction, and is moved to the diaphragm (1) side by a stopper (19) provided on the shaft portion. Is a blocked structure,
The movable plate (36) is arranged so as to be movable in parallel with the shaft portion, and an engagement piece (39) provided on the movable plate (36) contacts the spring receiver (18) from the diaphragm (1) side. It is a structure that touches.
[0008]
The above solution works as follows.
Normally, when the main valve is opened by operating the operation unit (21) and the ignition device (2) is operated, the water circuit is opened in response to the operation of the operation unit (21), and the gas valve is opened. (14) is opened, the gas burner is ignited, and the combustion of the gas burner results in a heat exchange state. In the case of the seed ignition system, the water circuit is opened by another operation after the seed ignition ignition operation, the gas valve (14) is opened, and the gas burner is ignited from the seed fire to enter a heat exchange state.
[0009]
At this time, the movable shaft (22) is in the advanced position by the operation of the operation unit (21), and then the diaphragm (1) is moved to the second chamber (12) side in the diaphragm chamber (D) when the water circuit is opened. The movable plate (36) is urged toward the advance position side of the movable shaft (22) by the spring (38). However, the interlocking relationship between the interlocking mechanism and the movable plate (36) is that the moving force of the movable plate (36) to the advance position is only due to the urging force of the spring (38). One end of 36) comes into contact with the movable shaft (22) in the advanced state, and further movement of the movable plate (36) is prevented.
[0010]
On the other hand, the interlocking mechanism between the diaphragm (1) and the gas valve (14) operates as it is, and the gas valve (14) is opened to connect the gas circuit from the gas inlet (31) to the gas outlet (33). Gas is supplied to the gas burner.
When the first chamber (11) in the diaphragm chamber (D) is frozen, the diaphragm (1) moves to the second chamber (12) side due to volume expansion, and the gas valve (14) is opened. At this time, the movable plate (36) operates in synchronization with the interlocking mechanism, and the one end of the movable plate (36) is moved to the protruding position. Even if the ignition operation is executed in this state, the advancement of the movable shaft (22) of the operation portion (21) is prevented by the movable plate (36), so that the operation of the ignition device is not executed. The diaphragm (1) may move to the second chamber (12) side due to the freezing and the gas valve (14) of the water pressure responsive gas valve may be in an open state. Apart from 14), there is a main valve that is opened in response to the ignition operation, so this main valve is kept closed.
[0011]
The interlocking mechanism has a shaft portion that connects the gas valve (14) and the diaphragm (1), and a spring (17) that biases the diaphragm (1) toward the first chamber (11) on the shaft portion. A spring receiver (18) is provided to support one end of the shaft.The spring receiver (18) is provided on the shaft portion so as to be movable in the axial direction, and is moved toward the diaphragm (1) by a stopper (19) provided on the shaft portion. The movable plate (36) is arranged to be movable in parallel with the shaft portion, and an engagement piece (39) provided on the movable plate (36) is provided on the spring receiver (18). On the other hand, the diaphragm (1) is in contact with the diaphragm.
[0012]
In this case, when the diaphragm (1) moves toward the second chamber (12) against the biasing force of the spring (17), the movable plate (36) moves to the protruding position by the biasing force of the spring (38). On the contrary, when the water circuit is closed, the diaphragm (1) connected to the shaft portion is moved to the first chamber (11) side by the urging force of the spring (17) to return to the initial state. At this time, the movable plate (36) is driven back to the retracted position against the urging force of the spring (38) by the engagement of the engaging piece (39) and the spring receiver (18).
[0013]
Therefore, the operation of each part does not occur.
About Claim 2 In the invention of Claim 1, “the gas valve (14) is biased in the valve closing direction by the spring (143) and the shaft portion opens the gas valve in the valve opening direction against the biasing force. The shaft portion is configured to open the gas valve (14) when the moving distance from the initial state of the diaphragm (1) to the second chamber (12) side exceeds a certain distance (L1), In the case where the fixed distance (L1) is set larger than the minimum distance (L2) from the retracted position to the protruding position of the movable plate (36), when the first chamber (11) is frozen, Since the moving distance (L2) until the movable plate (36) reaches the protruding position is smaller than the fixed distance (L1) for opening the gas valve (14), the gas valve (14) is opened. Before moving, the advancement of the movable plate (22) is always prevented. Therefore, there is no inconvenience that the ignition operation is performed even though the gas valve (14) is opened due to freezing.
[0014]
【The invention's effect】
In the first aspect of the invention, when the first chamber (11) of the diaphragm chamber (D) is frozen, the main valve is not opened, and the main valve of the gas circuit is placed in a closed state. The inconvenience of the release of raw gas can be prevented.
In addition, there is an effect that the device for preventing the valve opening operation can be mechanically realized. In particular, according to the present invention, when the valve opening operation is inhibited, the ignition operation is inhibited, so that the valve opening operation is more reliably prevented.
[0015]
Furthermore, the operation of the mechanism is smooth.
According to the second aspect of the present invention, when the ignition operation is performed when the first chamber (11) is frozen, the advance operation of the movable plate (22) is always performed before the gas valve (14) is opened. Is blocked. There is no inconvenience that the gas valve (14) opens and the gas valve (14) is open, and the ignition operation is performed.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Reference Example In the reference example shown in FIGS. 1 and 2, the movement detection means and the control means are realized by an electrical device. In this reference example, the operation of the ignition device (2) is controlled by a control device (C) constituted by a microcomputer. As the movement detecting means, a switch (41) interlocked with a reaction shaft (43) protruding outward from the second chamber (12) side of the diaphragm chamber (D) of the water pressure responsive gas valve is employed.
[0017]
In the gas circuit of the water pressure responsive gas valve, a main valve (42) interlocked with the operation part (21) of the ignition device (2) is inserted upstream of the gas valve (14), and downstream of the gas valve (14). Is connected to the gas burner (B). A spring (17) is interposed between the shaft (141) connecting the diaphragm (1) and the gas valve (14) and the valve body (3) so that the diaphragm (1) is in the first chamber (11 ) Side and the gas valve (14) in the valve closing direction. The water circuit is connected to the heat exchanger via a water valve (44).
[0018]
The control device (C) is configured to execute an operation based on the flowchart shown in FIG.
In this case, when the diaphragm (1) moves to the second chamber (12) side of the diaphragm chamber (D), the shaft portion (141) moves in the same direction against the spring (17), and the gas valve (14) Is opened and the response shaft (43) linked to the diaphragm (1) advances, so that the switch (41) is turned on.
[0019]
The signal of the switch (41) is input to the control device (C). An operation signal from the operation unit (21) is also input to the control device (C).
The operation when the ignition operation is performed will be described with reference to FIG.
When the control operation of the control device (C) is executed, first, the flag (F) as the storage means is set to zero. Thereafter, it is determined whether or not the switch (41) is ON. (ST-01) If the switch (41) is not ON, it is normal and the ignition operation is in a standby state (ST-02). If it is ON, the flag (F) is set to “1” (ST -03)
When the ignition operation is performed, it is determined whether the flag (F) is zero (ST-04).
[0020]
The signal indicating whether or not the ignition operation has been performed may be a signal of a switch (not shown) interlocked with the operation unit (21), and the signal when this switch is ON may be an ignition operation signal. The subsequent steps are executed by inputting the ON signal.
When the value of the flag (F) is “1”, the control operation is finished as it is, and the subsequent operation is not executed.
[0021]
If the flag (F) is zero, that is, if the switch (41) remains OFF at this time, the main valve (42) and the water valve (44) are opened. Then, the operation of the ignition device (2) is executed (ST-5). When the water valve (44) is opened, the water pressure responsive gas valve is activated, the gas valve (14) is opened, and the gas circuit to the gas burner (B) is communicated.
As a result, since the gas burner (B) is ignited, the heat exchange operation is executed. Of the operation of the ignition device (2), the discharge from the ignition electrode (P) is continued for a predetermined time and then stopped. (ST-06)
Now, when the diaphragm (1) is moved to the second chamber (12) side due to the expansion of water in the first chamber (11) due to freezing, the response shaft (43) advances and the switch (41) is turned on. "
[0022]
Therefore, when the operation of the control device (C) is executed, since the flag (F) is set to “1” (ST-03), the subsequent operation is stopped in step 4, and the main valve The valve opening operation is not executed.
Embodiment In this embodiment, the ignition operation itself can be mechanically blocked in order to prevent the ignition operation during freezing of the first chamber (11) in the diaphragm chamber (D). For this reason, as shown in FIG. 3, a movable plate (36) that operates in conjunction with the operation of the diaphragm (1) of the water pressure responsive gas valve is provided in the valve body (3).
[0023]
In the valve body (3), a valve chamber (32) is formed in a gas circuit extending from the gas inlet (31) to the gas outlet (33), and a valve seat provided in the middle of the valve chamber (32) ( The gas valve (14) is in contact with 16) by the urging force of the spring (143). The valve body (3) is provided with a diaphragm chamber (D) which is divided into a first chamber (11) through which water passes by a diaphragm (1) and a second chamber (12) open to the atmosphere. A main shaft (13) is connected to the surface of the diaphragm (1) on the second chamber (12) side, and the main shaft (13) is a component wall and valve of the second chamber (12) in the diaphragm chamber (D). It penetrates the body (3). The main shaft (13) is built in the valve body (3) so as to be positioned coaxially with the valve shaft (15) connected to the gas valve (14), and the gas outlet on the downstream side of the valve chamber (32) (33a) is connected to the valve shaft (15) in a spring chamber (170) provided at a predetermined interval.
[0024]
A certain range of the valve shaft (15) of the connecting portion is a large diameter portion, and a flange-like stopper (19) protrudes in a radial direction at a boundary portion between the large diameter portion and the main shaft (13). . A disk-shaped spring receiver (18) is slidably fitted to the large diameter portion and is in contact with the stopper (19). A spring (17) is interposed between one axial wall surface of the spring chamber (170) and the spring receiver (18), and the spring receiver (18) is in contact with the stopper (19). Therefore, the valve shaft (15) is biased toward the main shaft (13) by the biasing force of the spring (17), and when there is no water flow in the water circuit, the diaphragm ( 1) is in the initial state moved to the first chamber (11) side. The valve shaft (15) and the main shaft (13) may be integrated.
[0025]
One end of the valve shaft (15) is formed in a gas valve (14) and inserted into a hole (142) that opens to the valve shaft (15) side, and the gas valve (14) is inserted into a valve seat (16 ) And when the diaphragm (1) is in the initial state, as shown in FIG. 4, the valve shaft (15) is separated from the bottom of the hole (142) by a certain distance (L ₁ ). It has become. Therefore, when the diaphragm (1) moves a distance equal to or greater than the predetermined distance (L ₁ ) from the initial state, the valve shaft (15) resists the valve closing biasing force of the spring (143). Open the valve.
[0026]
As shown in FIG. 3, the valve body (3) has a mechanism chamber (34) that opens to one side and accommodates a spring (38), a hook (351), and a hanging plate (37), which will be described later. Has been. The mechanism chamber (34) is covered with a cover plate (35), and an opening (30) for engaging the spring receiver (18) with an engagement piece (39) of a hanging plate (37) described later is formed. Thus, the mechanism chamber (34) and the spring chamber (170) communicate with each other.
[0027]
An operation unit (21) of the ignition device (2) is attached to the upper side of the cover plate (35). The operation portion (21) is an operation shaft that is held up and down by a casing (211), and is urged in the upward direction by a spring (23) interposed between the operation plate (21) and the cover plate (35). ing. The operation part (21) is in a state of a pair of soot and the casing (211), and is configured to move up and down in a constant posture. A movable shaft (22) hangs down on one side of the lower end of the operation unit (21). In a state where the operation unit (21) is not pushed, that is, in an initial position, the lower end of the movable shaft (22) has a certain gap from the outer surface (upper surface) of the lid plate (35). A through hole (24) is formed at a position facing the lower end of the movable shaft (22), and when the movable shaft (22) is pushed in, the lower end is inserted into the through hole (24). It has become so. Further, the operation unit (21) is configured to manually open a main valve (42) and a water valve (44) described later by an interlocking mechanism (not shown) after the movable shaft (22) is inserted into the through hole (24). A switch (25) that controls the ignition device (2) and discharges the ignition electrode (P) is turned on.
[0028]
A movable plate (36) is slidably held on the upper surface of the lid plate (35). In order to hold the movable plate (36) on the upper surface of the lid plate (35), a holding plate (4) (4) connected to the valve body (3) and an upper surface of the lid plate (35). A gap slightly larger than the thickness of the movable plate (36) is formed therebetween. Thus, the sliding direction of the movable plate (36) is set parallel to the axial direction of the main shaft (13) and the valve shaft (15), and in the initial state of the movable plate (36), one end thereof is the transparent plate. Located in the vicinity of the hole (24). A suspension plate (37) is connected to the other end of the movable plate (36) so as to protrude into the mechanism chamber (34) from an opening formed in the lid plate (35) and to be an engagement piece connected to the protruding end. (39) projects from the opening (30) into the spring chamber (170), which faces the main shaft (13) side of the spring receiver (18).
[0029]
In place of the presser plates (4) and (4), as shown by an imaginary line in FIG. 4, a roller that is substantially in close contact with the upper surface of the movable plate (36) and is rotatable in the moving direction of the movable plate (36) (R) may be pivotally supported. In this case, since the resistance to the movable plate (36) is small, the movement of the movable plate (36) is not hindered.
A hook (351) projects downward from the lid plate (35) between the through hole (24) and the projecting portion of the hanging plate (37) in the mechanism chamber (34). A spring (38) is interposed between the hanging plate (37). As a result, the movable plate (36) is biased toward the casing (211). Therefore, the engagement piece (39) comes into contact with the spring receiver (18) from the main shaft (13) side in the spring chamber (170). The urging force of the spring (38) is set smaller than the urging force of the spring (17) that urges the valve shaft (15). Therefore, in the initial state of the diaphragm (1), the one end of the movable plate (36) is retracted farthest from the through hole (24) by the contact between the spring receiver (18) and the engaging piece (39). When the valve shaft (15) is driven by the diaphragm (1) in a direction to open the gas valve (14), the movable plate (36) is moved by the biasing force of the spring (38). Moves forward synchronously with the valve stem (15).
[0030]
The distance (L ₂ ) between the one end of the movable plate (36) at the retracted position and the movable shaft (22) above the through hole (24) is set to be smaller than the constant distance (L ₁ ).
Therefore, when the first chamber (11) is frozen and the diaphragm (1) is moved to the second chamber (12), the tip of the valve shaft (15) linked to this movement opens the gas valve (14). Prior to pushing out to the valve position, the one end of the movable plate (36) moves to a position (a position below the tip of the movable shaft (22)) that partially closes the through hole (24) to move the operation part (21) Even if is pushed, the movable shaft (22) is not inserted into the through hole (24), and the pushing operation of the operating portion (21) is prevented.
[0031]
When a water flow is generated in the first chamber (11) during normal operation, the diaphragm (1) moves beyond the predetermined distance (L ₁ ), and the tip of the valve shaft (15) is in the hole of the gas valve (14). The gas valve (14) is opened in contact with the bottom of the part (142).
The diaphragm chamber (D) of the water pressure responsive gas valve configured as described above is inserted into the water circuit to the heat exchanger, the gas inlet circuit is connected to the gas inlet (31), and the main valve (42) is connected to the gas inlet circuit. Has been inserted. A gas outlet (33) on the downstream side of the valve chamber (32) is connected to the gas burner (B).
[0032]
The main valve (42) opens after the operating portion (21) for operating the ignition device (2) is pushed from the initial position and the movable shaft (22) enters the through hole (24). . The operation unit (21) is held at the advanced position by a push-push mechanism having a heart cam mechanism (not shown). In the ignition device (2), the switch (25) is turned on by the operation of the operation unit (21) to discharge from the ignition electrode (P), thereby igniting the gas burner (B) and igniting by a timer (not shown). After that, the discharging operation is stopped. In the water circuit to the heat exchanger, a water valve (44) that is opened by the operation of the operation section (21) is inserted downstream of the diaphragm chamber (D).
[0033]
In a water heater with a built-in water pressure responsive gas valve, the main valve (42) opens after the movable shaft (22) enters the through-hole (24) by operating the operation unit (21) of the ignition device. At the same time, the water valve (44) of the water circuit is opened. Then, since the water flow is generated in the water circuit by opening the water valve (44), the diaphragm (1) moves to the second chamber (12) side by this, and the main valve (13) and the valve shaft (15) Are moved in the same direction. In conjunction with this, the engagement piece (39) and the one end of the movable plate (36) provided with the engagement piece (39) are biased by the spring (38) so as to move toward the through hole (24). However, since the movable shaft (22) is inserted into the through hole (24), the one end of the movable plate (36) abuts the movable shaft (22) from the side to prevent further sliding. However, the gas valve (14) is opened by the movement of the main shaft (13) and the valve shaft (15). As a result, the gas circuit to the gas burner (B) communicates.
[0034]
On the other hand, in response to the operation of the operation section (21), the ignition device is activated, and the gas burner (B) is ignited by the spark discharge from the ignition electrode (P). The discharge time due to the operation of the ignition device continues for a certain time, and then the discharge operation is stopped, and the heat exchange operation is continued by continuing combustion of the gas burner (B). When the operation unit (21) is operated again, the main valve (42) and the water valve (44) are closed, and the gas valve (14) is closed by the reverse operation of the water pressure responsive gas valve. The combustion of the gas burner (B) is stopped.
[0035]
When the diaphragm (1) is moved to the second chamber (12) side due to freezing, the valve shaft (15) is moved in the same direction, so that the movable plate (36) protrudes and the through hole (24) is moved. Block a part of. Therefore, even if the operating portion (21) is operated when the inside of the first chamber (11) is in a frozen state, the movable shaft (22) is not inserted into the through hole (24). And the water valve (44) does not open, and the ignition device (2) does not start because the switch (25) does not conduct. That is, the discharge operation is not executed.
[0036]
Each part of the above-mentioned embodiment can be changed as follows.
1. In the above-described embodiment, the ignition operation of the operation unit (21) of the ignition device (2) opens the main valve (42) and the water valve (44), and spark discharges from the ignition electrode to the gas burner (B). An example of a water heater that discharges water at the same time as ignition is illustrated, but the ignition valve opens the main valve (42) to ignite the seed burner, and then opens the water valve (44) by another operation. Thus, the present invention may be applied to a seed-fire ignition type water heater in which the gas circuit is opened by the action of the water pressure responsive gas valve so that the gas burner is ignited and discharged.
2. In the above embodiment, the main valve (42) and the water valve (44) are opened manually by operating the operation unit (21), but these valves are, for example, electromagnetic valves that are controlled to open and close by the switch (25). Also good. In addition, the second chamber (12) is open to the atmosphere, but water having a lower pressure (secondary pressure water) than the first chamber (11) may flow into a part of the second chamber (12).
[Brief description of the drawings]
FIG. 1 is an overall explanatory diagram of a reference example. FIG. 2 is a flowchart of a control device (C) used in the reference example. FIG. 3 is an overall explanatory diagram of this embodiment. Relationship diagram with (L2) [Explanation of symbols]
(1) ... Diaphragm
(2) ... Ignition device
(3) ... Valve body
(11) ・ ・ ・ Room 1
(12) ... Second room
(14) ・ ・ ・ Gas valve
(31) ・ ・ ・ Gas inlet
(33) ・ ・ ・ Gas outlet
(D) ・ ・ ・ Diaphragm room

Claims (2)

An ignition device (2) for igniting a gas burner in response to an ignition operation, a main valve for opening a gas circuit to the gas burner in response to the ignition operation, and a gas in response to opening and closing of a water circuit A water pressure responsive gas valve for opening and closing the gas valve (14) of the circuit, and a water heater in which the water circuit is opened after the ignition operation,
The main valve is provided in series with the gas valve (14) in the gas circuit, and the ignition device (2) is in an operating state when the movable shaft (22) is advanced by operation of the operation unit (21). And
The water pressure responsive gas valve divides the diaphragm chamber (D) into a first chamber (11) connected to the water circuit and a second chamber (12) side, and the first chamber when the water circuit is opened. A diaphragm (1) for opening the gas valve (14) in conjunction with movement toward the second chamber (12) accompanying a change in pressure on the (11) side, and the diaphragm (1) and the gas valve ( 14), the gas valve (14) is opened by the movement of the diaphragm (1) to the second chamber (12) side and the spring is forced to the first chamber (11) side. With an interlocking mechanism with a restoring force,
A movable plate that is linked to the diaphragm (1) and moves between a projecting position where one end projects into the advancement region of the movable shaft (22) and prevents the advancement of the movable shaft (22) and a retracted position retracted from the position. (36)
The movable plate (36) is biased in the protruding direction by a spring (38),
The movable plate (36) is driven in the protruding direction by the urging force of the spring (38) when the diaphragm (1) moves toward the second chamber (12), and the first chamber (1) of the diaphragm (1) ( 11) When moving to the side, the interlocking mechanism is retracted by the forced return force of the interlocking mechanism,
The interlocking mechanism has a shaft portion connecting the gas valve (14) and the diaphragm (1), and the shaft portion has one end of a spring (17) for urging the diaphragm (1) toward the first chamber (11). A spring receiver (18) is provided to support the shaft, and the spring receiver (18) is provided on the shaft portion so as to be movable in the axial direction, and is moved to the diaphragm (1) side by a stopper (19) provided on the shaft portion. Is a blocked structure,
The movable plate (36) is arranged so as to be movable in parallel with the shaft portion, and an engagement piece (39) provided on the movable plate (36) contacts the spring receiver (18) from the diaphragm (1) side. A water heater safety device that comes in contact with the water heater.   The gas valve (14) is biased in the valve closing direction by a spring (143) and the shaft portion drives the gas valve in the valve opening direction against the biasing force. When the moving distance from the initial state of 1) to the second chamber (12) side exceeds a certain distance (L1), the gas valve (14) is opened, and the certain distance (L1) is the movable plate ( The water heater safety device according to claim 1, wherein the safety device is set larger than a minimum distance (L2) from the retracted position to the protruding position in 36).

Images