JPS6237733B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a combustion control device for controlling the combustion of a plurality of combustors, each of which can be independently blinked, and at least one of which is equipped with a water temperature detection circuit for detecting the temperature of water in a bathtub. , the purpose is to prevent one hot water temperature detection circuit from malfunctioning due to the ignition operation of the other.

For example, in a bathtub with a gas water heater, etc., both combustors are configured so that they can be operated independently, and
If the combustion control circuit on the bath side is equipped with a temperature detection circuit that stops combustion of the burner when the water temperature in the bathtub reaches the set temperature, the burner will stop burning when the water temperature in the bathtub reaches close to the set temperature. When an ignition operation is performed on the water heater side, the noise caused by this discharge may cause the hot water temperature detection circuit to malfunction, causing the burner to stop burning when the temperature falls below the set temperature.

Therefore, the present invention is constructed to prevent the above-mentioned malfunction, and below, first, FIG. 1 will be explained.

Reference numeral 1 denotes the main body of a bathtub with a gas water heater, in which a bath heat exchanger 3 and a water heater heat exchanger 4 are arranged side by side in an exterior case 2, and burner sets 5 and 6 are installed below these, respectively. It is set up. Further, exhaust guides 7 and 8 are connected above each of the heat exchangers 3 and 4, and the upper ends of these guides are opened in an exhaust top 9 attached to the upper part of the outer case 2. Furthermore, the burner sets 5 and 6 are provided with first, second, third and fourth solenoid valves 11 and 1 which are operated by a control circuit 10.
2, 13, 14 interposed gas supply paths 15, 16
The spark plugs 17 and 18 for bath and hot water supply and flame detection rods 19 and 20, which are controlled in the same way, are connected to each other.

Reference numeral 21 denotes a water jacket that is integrally interposed in the heat exchanger 3 between a pair of upper and lower communication pipes 23 and 23' that communicate the bath heat exchanger 3 and the inside of the bathtub 22, and is used to connect the communication pipes 23 and 23'. It has a cylindrical shape slightly longer than its position, and houses a hot water temperature detection sensor 25 formed by connecting a plurality of diodes 24, 24', . . . .

FIG. 2 is a circuit diagram showing the aforementioned control circuit 10,
A bath control circuit 32 and a hot water supply control circuit 33 are connected in parallel to a low-voltage DC power supply 31 of about 30 V through a normally open push button switch 34 on one side and a well-known running water switch 35 on the other.

First, the bath control circuit 32 will be explained. 36 is a first switching element connected after the push button switch 34 via a diode 37, and a transistor whose base input is connected to the output of a hold timer 38 such as a CR timer. 39
are connected. The hold timer 38 turns off the transistor 39 for a predetermined period of time after energization by closing the pushbutton switch 39, and turns off the first switching element 3.
Turn on 6. 40 and 41 are the hold timer 38
The first and second comparators constitute a forced ignition timer set shorter than the resistor 42 and capacitor 4.
3 as input, and the first comparator 4
0 and the second comparator 41 both the first switching element 3
6 is turned on, outputs a low level for a predetermined period of time. 4
4 and 45 are electromagnetic coils of the first and second electromagnetic valves 11 and 12, and a second switching element 47 connected to the base of a transistor 46 connected between the push button switch 34 and the diode 37 and connected to the hold timer 38; and a Darlington-connected transistor 5 in which the output of the second comparator 41 is connected via a transistor 48 and a diode 49.
0 and 51 are connected in series. Therefore, within the set time of the forced ignition timer and the hold timer 38, the second switching element 47 is turned on by turning off the transistor 46, and the electromagnetic coil 44 is turned on by turning on the transistors 50 and 51 when the transistor 48 is turned off. 45 is energized, the first and second
Solenoid valves 11 and 12 are opened.

Reference numeral 52 denotes a flame detection circuit using a well-known FET 53 connected after the first switching element 36, and an ignition display circuit 56 comprising a transistor 54 and a light emitting diode 55 is connected to the output. Reference numeral 57 denotes a self-holding relay in which a transistor 58 connected in series receives the output of the flame detection circuit 52, and its normally open contact 57' is connected in parallel to the push button switch 34 via a normally closed stop switch 59. ing.
Furthermore, 60 is a hold circuit which holds the hold timer 38 which receives the output of the flame detecting circuit 52 in an operating state and maintains the transistor 39 in an off state, and is composed of a transistor or the like. The output of the flame detection circuit 52 is also connected between the diode 49 and the transistor 50 via diodes 61 and 62, so that the presence of a flame can be detected even after the second comparator 41 has finished the timer. If so, the transistors 50 and 51 are turned on and the first and second solenoid valves 11 and 12 are continuously opened.

63 is the first switching element 36 as described above.
In the hot water temperature detection circuit configured in the latter stage, the hot water temperature detection sensor 2 whose voltage is made constant by the transistor 64
A third comparator 66 compares the output of sensor 24 with the output corresponding to the set temperature by variable resistor 65, and the output of this comparator is compared with the reference input by resistors 67 and 68 to determine whether the output of sensor 24 is When the output corresponding to the set temperature is reached and the output of the third comparator 66 is inverted to a high level output, the fourth comparator 69 receives this and outputs an inverted high level output.
The output of this fourth comparator 69 is connected to the gate of the SCR 70 connected to the base of the first switching element 36, and when the water temperature in the bathtub 22 reaches the set temperature, the SCR 70 is turned on and the first switching element 36 is turned on. Turn off.

Next, the hot water supply control circuit 33 will be explained.
Numeral 81 is a third switching element which is connected to the downstream side of the flush water switch 35 via a diode 82 in the same way as the one for the bath, and has a base connected to a transistor 84 which is connected to a hold timer 83. 85,
86 is the fifth and sixth comparators of the forced ignition timer provided after the third switching element 81;
A common CR timer consisting of a resistor 87 and a capacitor 88 is connected to the input. Reference numerals 89 and 90 denote electromagnetic coils of the third and fourth electromagnetic valves 13 and 14, and a transistor 9 connected between the water switch 35 and the diode 82 and connected to the hold timer 83.
1 is connected to the base of the fourth switching element 92
and an electromagnetic valve circuit 93 constituted by the Darlington-connected transistors and the like are connected in series. The solenoid valve circuit 93 is connected to the sixth comparator 86.
When the hold timer 83 and the forced ignition timer are activated by the sixth comparator 86 after the water flow switch 35 is closed, the fourth switching element 92 is turned on and the solenoid valve circuit 93 is activated to control the third and fourth Open the solenoid valves 13 and 14.

94 is a flame detection circuit using FET 95, the output of which is connected to a solenoid valve circuit 93 and a hold circuit 96. When this hold circuit 96 receives an output indicating that there is a flame from the flame detection circuit 94, the hold timer 8
3 in the activated state, and the third switching element 8
Turn on 1 continuously. When the electromagnetic valve circuit 93 also receives an output indicating that there is a flame from the flame detection circuit 94, it controls the energization of the third and fourth electromagnetic coils 89 and 90 regardless of the output of the sixth comparator 86.

Further, 97 is an inverter circuit for obtaining alternating current signals for flame detection and discharge ignition, which is supplied with power from the second switching element 47 and fourth switching element 92 via backflow prevention diodes 98 and 99, respectively, and is connected to an inverter transformer. A diode 102 and a capacitor 10 are connected to one of the secondary windings 101 of 100.
3. An igniter 108 consisting of a trigger element 104, a step-up transformer 105, and an ignition switching element 107 whose input is the output via the diode 106 of the first comparator 40 and the fifth comparator 85 is connected; The above-mentioned rods 19 and 20 are connected to the secondary winding 109 through DC blocking capacitors 110 and 111, respectively. Furthermore, this rod 1
9, 20 and the capacitors 110, 111 are connected to flame detection circuits 52, 94 corresponding to each of the above,
The signal is obtained from this by the rectifying effect of the flame. Further, the double-wound secondary winding 11 of the step-up transformer 105
2 and 112' are the aforementioned spark plugs 17 and 1, respectively.
8 is connected.

Further, the output of the fifth comparator 85 constituting the forced ignition timer on the hot water supply side is connected to the hot water temperature detection circuit 63.
It is connected to the base of a transistor 115 that constitutes a correction circuit 114 connected between a reference side input 113 corresponding to the set temperature of the third comparator 66 and ground, and when the fifth comparator 85 is in operation, that is, on the hot water supply side. During the ignition operation, the reference side input 113 of the third comparator 66
is forcibly lowered to a low level, shifting its operating temperature to a higher temperature side and preventing the third comparator 66 from malfunctioning, which would result in noise generated by the igniter 108.

To briefly explain the operation on the bath side, the hold timer 3 is activated by closing the push button switch 34.
8 is activated, the first and second switching elements 36,
47, the forced ignition timer by the first and second comparators 40 and 41 also operates. As a result, the first and second solenoid valves 11 and 12 are opened, and at the same time, the igniter 108 is operated, and the burner set 5 is ignited. When the burner set 5 is ignited, the FET 53 of the flame detection circuit 52 turns off and detects this, and the hold circuit 60 continues to operate the hold timer 38 and turns on the transistors 50 and 51 to turn on the first and second transistors. 2 continues to open the solenoid valves 11 and 12, and the transistor 58 is turned on to turn on the self-holding relay 5.
7 and closes its contact 57'. After confirming this by the light emission from the light emitting diode 55, the push button switch 34 is released.

On the other hand, when the water temperature in the bathtub 22 reaches the set temperature,
The output of the third comparator 66 is inverted to high level, the output of the fourth comparator 69 is inverted to high level,
Turn on the SCR 70 and turn on the first switching element 36.
is turned off to cut off the power supply to subsequent stages, so that the contact 57' of the self-holding relay 57 opens and combustion in the burner set 5 is stopped. If you wish to stop combustion midway through, open the stop switch 59.

Next, to briefly explain the operation on the hot water supply side, when the running water switch 35 is closed due to opening of the hot water faucet, etc., the hold timer 83 is activated and turns on the third and fourth switching elements 81 and 92, as well as for forced ignition. The solenoid valve circuit 93 is actuated by the outputs of the fifth and sixth comparators 85 and 86 constituting the timer to open the third and fourth solenoid valves 13 and 14, and at the same time, the igniter 108 is actuated to ignite the burner set 6. Perform the action. As a result, when the burner set 6 is ignited, the FET 95 of the flame detection circuit 94 turns off and detects this, activates the hold circuit 96 to maintain the hold timer 83 in the operating state, and continues to operate the solenoid valve circuit 93. Then, the third and fourth solenoid valves 13 and 14 continue to be opened. The igniter 108 is stopped by the reversal of the fifth comparator 85 after a predetermined operating time, but the configuration is such that the output of the flame detection circuit 94 is used to stop the operation of the igniter 108 in a short time after ignition. You may do so. If the ignition operation on the hot water supply side is performed while the bath side is in operation, the output of the fifth comparator 85 turns on the transistor 115 of the correction circuit 114 to adjust the reference side input level of the third comparator 66. This lowers the operating temperature of the third comparator 66 to a higher temperature side to prevent, for example, premature disconnection due to malfunction of the third comparator 66.

As described above, the present invention provides a plurality of combustors, each of which can be individually controlled to blink, and at least one of which is provided with a hot water temperature detection circuit using a comparator that stops combustion when the temperature of the heated object reaches a set temperature. The combustion control device is characterized by being provided with a correction circuit that shifts the operating temperature of the comparator of the hot water temperature detection circuit to a higher temperature side in conjunction with the ignition operation of the other combustor, For example, even if another combustor is ignited while the hot water temperature detection circuit is in operation, such as when heating hot water in a bathtub, malfunction of the hot water temperature detection circuit due to igniter noise is reliably prevented. This can prevent the burner from stopping combustion before the water temperature in the bathtub reaches the set temperature.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram of a bathtub with a gas water heater equipped with a combustion control circuit according to the present invention, and FIG. 2 is a circuit diagram of the same. 63... Hot water temperature detection circuit, 66... Third comparator,
114...Correction circuit.

Claims (1)

[Claims] 1. A plurality of combustors arranged in close proximity can each be independently controlled to blink, and at least one is equipped with a comparator that compares the temperature of the heated object with a set value, and the combustor is controlled by the output of this comparator. Combustion control is provided with a hot water temperature detection circuit for stopping combustion of the combustor, characterized in that a correction circuit is provided for shifting the operating temperature of one of the comparators to a higher temperature side when the other combustor is ignited. Device.