JP3088271B2 - Combustion equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a combustion apparatus.

[0002]

2. Description of the Related Art As a combustion apparatus, for example, in a gas water heater, an electromagnetic valve is provided in a gas supply path to a gas burner. Further, as an ignition means of a gas burner, for example, an ignition device that generates a high voltage by being energized and performs spark discharge is known. And the above-mentioned solenoid valve and the ignition device,
When a transistor is connected to a DC power supply (for example, a dry battery) via a transistor and an ON signal is input to the transistor, the solenoid valve and the ignition device are energized.

More specifically, when a water flow switch for detecting a water flow is closed, a transistor for controlling energization of an electromagnetic valve or an ignition device is supplied for a predetermined time (for example, 5 seconds) based on the closing signal (ignition signal). ), A holding timer circuit and an ignition timer circuit for transmitting an ON signal are connected. In some cases, a thermal fuse electrically connected between the transistor and the solenoid valve is disposed near the heat exchanger to prevent the heat exchanger from overheating.

[0004]

In the above-mentioned gas water heater, once the thermal fuse is blown, the holding current cannot be passed to the solenoid valve. Users cannot use gas water heaters. However, even in such a state, the ignition circuit can be operated and spark discharge is performed. Therefore, there is a possibility that the user may misunderstand that the gas water heater has not failed and perform the ignition operation many times.

[0005] An object of the present invention is to provide a combustion device excellent in safety, in which a normal ignition operation is not performed when a thermal fuse blows due to overheating.

[0006]

In order to solve the above-mentioned problems,
The present invention employs the following configuration. A solenoid valve disposed in a gas supply path for supplying gas to the gas burner, the valve body being opened by energization, a heat exchange channel having a heat exchange section heated by the gas burner, and a water flow flowing through the heat exchange channel A water flow switch that closes a contact when detecting, a temperature fuse that is disposed near the heat exchange section and blows at a predetermined temperature or higher, and an operating power is supplied from a battery through the water flow switch and the temperature fuse. A power supply line for operation, a switch element connected between the solenoid valve, and a predetermined time when power for operation is connected to the power supply line for operation, an ignition timer circuit for sending out an ignition signal, And an ignition circuit that performs an ignition operation while the ignition signal is being input, and is connected to the operation power supply line, and when the operation power is supplied, the switch is forcibly applied for the predetermined time. A holding timer circuit that sends an ON signal to the switch, and is connected to the power supply line for operation, and starts detection of combustion flame when power for operation is supplied. A safety circuit for transmitting an ON signal.

[0007]

[0008]

[0009]

When water flows through the heat exchange channel, the contact of the water flow switch is closed, and the power for operation is supplied from the battery to the power supply line for operation via the water flow switch and the temperature fuse. An ignition timer circuit connected to the operating power supply line sends out an ignition signal for a predetermined time, and the ignition circuit performs an ignition operation while the ignition signal is being input. The holding timer circuit connected to the operating power supply line sends an ON signal to the switch element for a predetermined time, and the switch element turns ON, so that the solenoid valve maintains the open state. When the safety circuit connected to the power supply line for operation detects the combustion flame during a predetermined time, it starts sending an ON signal to the switch element, and after the lapse of the predetermined time, the solenoid valve keeps the valve open, and the gas burner operates. Continue burning. When the thermal fuse blows due to overheating, even if water flows in the heat exchange water channel and the contact of the water flow switch is closed, the operating power is not supplied to the operating power supply line. Therefore, no operating power is supplied to the switch element, the holding timer circuit, and the safety circuit. Also, the ignition timer circuit does not send out the ignition signal, the ignition circuit does not perform the ignition operation, the holding timer circuit does not send out the ON signal to the switch element, the safety circuit does not start detecting the combustion flame, and the electromagnetic valve Keeps the valve closed,
The gas burner maintains the fire extinguishing state.

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

[0016]

[0017]

[0018]

The temperature fuse is electrically connected in series with the water flow switch, and the operating power is supplied from the battery to the operation power supply line via the water flow switch and the temperature fuse. A switch element, an ignition timer circuit, a holding timer circuit, and a safety circuit are connected to the operating power supply line. If the thermal fuse blows due to overheating,
The operation power is not supplied to the operation power line. In this case, even if the water flows into the heat exchange water channel and the contact of the water flow switch is closed, the switch element, the ignition timer circuit, the holding timer circuit, and the safety circuit are not operated because the operating power is not supplied and the ignition circuit is not operated. Performs no ignition operation (ignition signal is not input from the ignition timer circuit). That is, when the thermal fuse is blown, the ignition operation is not performed even if the user performs an ignition operation to flow water into the heat exchange water passage. For this reason, the safety is excellent, and the user can be informed that the combustion device is out of order, and the repair request can be reliably made.

[0019]

[0020]

[0021]

[0022]

[0023]

[0024]

[0025]

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. As shown in the figure, a gas instantaneous water heater A has an attraction coil 11 and a holding coil 12, and is provided with an electromagnetic safety valve 1 disposed in a gas pipe 21 for supplying gas to a gas burner 2,
A heat exchange channel 3 having transistors 13 and 14, a heat exchanger 31, a water flow switch 4 that closes a contact 41 when a water flow is detected, and a thermal fuse 4 that blows when an overheat is detected.
2, the igniter timer circuit 51, the igniter drive circuit 52, and the first timer time (0.
Suction timer circuit 6 that sends an ON signal 61 for 4 seconds)
When the contact 41 is closed, the holding timer circuit 7 which sends the ON signal 71 for the second timer time (5.5 seconds), and when the contact 41 is closed, detection of the combustion flame is started, and the combustion flame is detected. And an ignition detection circuit 8 that sends an ON signal 81 to the transistor 14 during the operation.

Reference numeral 91 denotes a regulator. When the contact 41 is closed, a voltage V _CC2 (3 V) is applied to an “IN” terminal 910 and a stabilized voltage V _CC is applied to an “OUT” terminal 911.
_REG (1.5 V) occurs. Reference numeral 92 denotes a dry battery. In this embodiment, two single 1.5 V manganese dry batteries are connected in series to generate an electromotive force of a voltage V _CC1 (3 V). Reference numeral 9 denotes an electronic unit in which each circuit is incorporated.

The electromagnetic safety valve 1 has a suction coil 11 (3.7 Ω) whose valve body opens when energized, and a holding coil 12 (500 Ω) for maintaining the valve open state even after suction by energization. It is arranged at the uppermost stream of the pipe 21.

The gas burner 2 is installed below the heat exchanger 31 and is supplied with gas by the gas pipe 21 and burns.
The gas pipe 21 is provided with an electromagnetic safety valve 1, a gas governor valve 211, a water pressure automatic gas valve 212 connected to a water governor 323, and a capacity adjuster 213 from the upstream side.

The combustion cylinder near the heat exchanger 31 has 152
A thermal fuse 42 that melts at a temperature equal to or higher than ° C. is provided.
One end of the thermal fuse 42 is electrically connected to the water flow switch 4, and the other end is electrically connected to the “IN” terminal 910.

The automatic hydraulic gas valve 212 is connected to the water governor 323 by the interlocking rod 43 and opens when water flows into the heat exchange water passage 3. The ability adjuster 213 is provided with the ability adjust knob 2.
14 and passes an amount of gas corresponding to the sliding amount of the capacity adjustment knob 214.

The heat exchange channel 3 is provided with a water supply pipe 32, a heat exchanger 3
1. The tapping pipe 33 is sequentially connected. Water supply pipe 32
Is provided with a hot water tap (not shown), a water filter 321, a water governor 323, and a hot water volume controller 325 connected to a hot water temperature control knob 324. The water flow switch 4 is inserted between the dry cell 92 and the thermal fuse 42, and is connected to the water governor 323.
And an interlocking rod 43 connecting the automatic water pressure gas valve 212 and the contact point 41 is closed when the water flows. The output side of the water flow switch 4 is an operating power supply line R.

The igniter timer circuit 51 sends an operation signal 511 to the igniter drive circuit 52 for 5.5 seconds from the start of power supply due to the closing of the contact 41. The igniter drive circuit 52 generates a high voltage for spark discharge while the operation signal 511 is being input, and applies the high voltage for ignition to the ignition electrode 521 disposed facing the gas burner 2. Since the igniter drive circuit 52 consumes a relatively large amount of current, the voltage V _CC1 is used as the operating power.

The ignition detecting circuit 8 is a circuit for detecting a flame current by applying an AC voltage (about 100 V) for detecting a flame current to a frame rod 80 provided facing the gas burner 2. Upon detection (detection of ignition), an ON signal 81 is sent to the transistor 14. Note that the voltage V _CC2
Is the operating power.

The suction timer circuit 6 includes a comparator, CR
When a stabilizing voltage V _REG is supplied as a timer operation start signal, an ON signal 61 is sent to the transistor 13 for a first timer time (0.4 seconds). The transistor 13 is disposed between the suction coil 11 and the dry cell 92, and conducts while the ON signal 61 is being input, so that a suction current flows through the suction coil 11.

The holding timer circuit 7 includes a comparator, CR
When a stabilizing voltage V _REG is supplied as a timer operation start signal, an ON signal 71 is sent to the transistor 14 for a second timer time (5.5 seconds).

The transistor 14 has a holding coil 12-
The electromagnetic safety valve 1 is disposed between the “OUT” terminals 911 and conducts while the ON signal 71 or the ON signal 81 is being input to supply a holding current to the holding coil 12 to keep the electromagnetic safety valve 1 open.

Next, the operation of the instantaneous gas water heater A will be described with reference to FIG.
This will be described based on the flowchart of FIG. 5 and the time chart of FIG. [Start of use of the appliance (see FIG. 4)] When the user opens the hot water tap (step s1), the water flow switch 4 is closed (step s2), and the voltage V _CC2 is supplied to the “IN” terminal 910 of the regulator 91. Then, a stabilized voltage V _REG is generated at the “OUT” terminal 911.

When the power supply of the stabilized voltage V _REG is started, the following operation is performed in step s3. The igniter timer circuit 51 sends an operation signal 511 to the igniter drive circuit 52, and the igniter drive circuit 52 applies a high voltage to the ignition electrode 521, and spark discharge starts. The suction timer circuit 6 sends an ON signal 61 to the transistor 13, and the transistor 13 is turned on to supply a suction current to the suction coil 11, so that the electromagnetic safety valve 1 is opened. The holding timer circuit 7
An ON signal 71 is sent to the transistor 14, which conducts and causes a holding current to flow through the holding coil 12.

In step s4, the automatic hydraulic gas valve 212 is opened, and the gas burner 2 is ignited. 0.4 seconds have passed since the closing of the water flow switch 4 was started (YES in step s5).
And the suction timer circuit 6 outputs the ON signal 61 to the transistor 1
3, the transistor 13 is turned off, and the attraction current does not flow through the attraction coil 11 (step s).
6).

When 5.5 seconds have elapsed since the closing of the water flow switch 4 (YES in step s7), the holding timer circuit 7
Stops sending the ON signal 71 to the transistor 14,
The igniter timer circuit 51 does not send out the operation signal 511 to the igniter drive circuit 52, and the spark discharge stops (step s8).

As shown in FIG. 6A, in the case of "normal", the ignition detection circuit 8 has already detected the flame current and the ON signal 8
1 is sent to the transistor 14 (YES in step s9), so that the holding of the electromagnetic safety valve 1 is continued. Voltage V
_CC1 is 1.8 V or more (YE in step s10)
S) If the flame current is detected, the hot water supply is continued until the use of the appliance is stopped.

When no flame current is detected {no ignition; FIG. 6 (b)}, when no flame current is detected {misfire; FIG.
(C)}, or when the voltage V _CC1 becomes less than 1.8V {voltage drop; FIG. 6 (d)}, the confirmation lamp 93 is continuously lit, and the transistor of the ON signal 81 by the ignition detection circuit 8 is used. The transmission to S14 stops (step s11). As a result, the electromagnetic safety valve 1 closes.

When the user notices an abnormality and closes the hot water supply valve (step s12), the water stops flowing, so the automatic water pressure gas valve 212 is closed (step s13), the water flow switch 4 is turned off, and the confirmation lamp 93 is turned on. The light is turned off (step s14).

[Suspension of use of appliance (see FIG. 5)] In order to stop use, the user closes the hot water supply valve (step S1).
Since water stops flowing, the automatic hydraulic gas valve 212 is closed (step S2), and the gas burner 2 is extinguished (step S3).
Then, the water flow switch 4 is turned off (step S4), and the electromagnetic safety valve 1 is closed (step S5).

[When the thermal fuse 42 is blown] FIG.
When the user opens the hot water tap, water flows and the water flow switch 4 is closed, but the temperature fuse 42 is blown, so that the voltage V _CC2 is applied to the “IN” terminal 910 of the regulator 91 as shown in FIG. No stabilization voltage V _REG is output to the “OUT” terminal 911.

Therefore, the stabilized voltage V _REG is not supplied to the transistor 14, the suction timer circuit 6, the holding timer circuit 7, and the igniter timer circuit 51, and the voltage V _CC2 is not supplied to the ignition detection circuit 8. Then, the suction timer circuit 6
Does not send the ON signal 61 to the transistor 13, the igniter timer circuit 51 does not send the ignition signal 511, the holding timer circuit 7 does not send the ON signal 71 to the transistor 14, and the ignition detection circuit 8 detects the combustion flame. Is not started, the electromagnetic safety valve 1 maintains the valve closed state, and the gas burner 2 maintains the fire extinguishing state.

The instant gas heater A has the following advantages [A] to [D] due to the following configuration and operation. Thermal fuse 4
2 has one end electrically connected to the water flow switch 4 and the other end electrically connected to the “IN” terminal 910 of the regulator 91 (electrical connection with the water flow switch 4 in series).

When the thermal fuse 42 is blown, the user performs an ignition operation (opens a hot water tap and flows water through the heat exchange water passage 3).
And the contact 41 of the water flow switch 4 is closed, the transistor 14, the suction timer circuit 6, the holding timer circuit 7,
The igniter timer circuit 51 is not supplied with the stabilized voltage V _REG , and the ignition detection circuit 8 is not supplied with the voltage V _CC2 .

[A] Even if the user performs an ignition operation when the thermal fuse 42 is blown, the suction current does not flow and the raw gas is not released, so that it is safe. [A] If the user performs an ignition operation when the thermal fuse 42 is blown, no spark discharge (snapping sound) occurs, the confirmation lamp 93 does not turn on, and the normal operation and display are not performed. It is easy to tell that the gas water heater is out of order. [C] When the thermal fuse 42 is blown, the user notices a failure and stops using the battery, so that the battery can be prevented from being consumed and a repair request can be promptly made.

(D) Since the power supply (a large current flows) for operating the igniter drive circuit 52 and the transistor 13 does not pass through the temperature fuse 42 or the water flow switch 4, the contact 4
This prevents the thermal fuse 42 from being fused due to welding, defective contacts, and a large current. In the above-described embodiment, the solenoid valve has a suction coil and a holding coil separately. However, a single coil may be used for both suction and holding. Further, in the above embodiment, the water heater is shown as the combustion device, but it may be applied to another combustion device such as a fan heater.

[Brief description of the drawings]

FIG. 1 is an external view of a gas instantaneous water heater according to one embodiment of the present invention.

FIG. 2 is a configuration diagram of the instant gas water heater.

FIG. 3 is an electrical connection diagram of the instant gas water heater.

FIG. 4 is a flowchart showing the operation of the instant gas heater.

FIG. 5 is a flowchart showing the operation of the instant gas heater.

FIG. 6 is a time chart showing the operation of the instant gas heater.

[Explanation of Symbols] A Gas instantaneous water heater (combustion device) 1 Electromagnetic safety valve (Solenoid valve) 2 Gas burner 3 Heat exchange channel 4 Water flow switch 6 Suction timer circuit 7 Holding timer circuit 8 Ignition detection circuit (Safety circuit) 14 Transistor ( Switch element) 21 gas pipe (gas supply path) 31 heat exchanger (heat exchange section) 41 contact 42 temperature fuse 51 igniter timer circuit (ignition timer circuit) 52 igniter drive circuit (ignition circuit) 61 on signal 71 on signal 92 dry cell 511 Operation signal (ignition signal) V _CC2 voltage (ignition instruction signal, operation power) V _REG stabilization voltage (ignition instruction signal, operation power)

Claims (1)

(57) [Claims] An electromagnetic valve disposed in a gas supply path for supplying gas to a gas burner, the valve body being opened by energization; a heat exchange channel having a heat exchange section heated by the gas burner; A water flow switch whose contacts are closed when a water flow flowing through the water passage is detected; a temperature fuse disposed near the heat exchanging section and blown at a predetermined temperature or higher; and a battery through the water flow switch and the temperature fuse. An operating power supply line to which operating power is supplied, a switch element connected between the solenoid valve, and an ignition signal transmitted for a predetermined time when the operating power is supplied to the operating power supply line. An ignition timer circuit that performs an ignition operation while the ignition signal is being input; and an ignition circuit that is connected to the power supply line for operation and is supplied with power for operation. A holding timer circuit that sends an ON signal to the switch element, and is connected to the power supply line for operation, starts detection of combustion flame when power for operation is supplied, and while the combustion flame is detected, A safety circuit for sending an ON signal to the switch element.