JPH0587334A - Controlling device of combustion - Google Patents

Abstract

PURPOSE:To simplify a combustion amount setting circuit in a combustion control circuit of a gas hot water supplier or the like and thereby to enable execution of rational design and manufacture. CONSTITUTION:Giving the same instruction on the amount of combustion at the time of ignition as the one on the amount of combustion at the time of steady burning, a microcomputer 12 outputs signals from ports X and Z to turn transistors 13 and 17 ON and thereby gives an instruction on the flow rate of gas for ignition of a proportional valve 8. In this way, a combustion amount setting circuit B which gives an instruction on output of a drive signal for the proportional valve 8 is simplified. Accordingly, a control circuit is simplified and the effects of improvement in reliability, improvement in economics, shortening of the time for inspection, etc., are produced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion control device such as a gas water heater using gas as fuel.

[0002]

2. Description of the Related Art Conventionally, a combustion control device such as a water heater has a slow ignition circuit in a combustion control circuit for specifying and setting a combustion amount of a burner at the start of combustion. The combustion amount of the slow ignition circuit is set to be smaller than that during steady combustion to prevent explosion ignition, or set to be larger than during steady combustion to ensure ignition, and a separate combustion amount setting circuit is provided during steady combustion after ignition. The steady combustion amount was set by.

That is, at the time of ignition, the combustion was started with a specific combustion amount, and during the subsequent steady combustion, the combustion was continued with the combustion amount corresponding to the set load.

[0004]

However, in the above configuration, the slow ignition circuit and the combustion amount setting circuit are separately required, and the combustion control circuit is complicated and large, which is extremely uneconomical in circuit design and manufacturing. ， It was irrational.

Therefore, the present invention does not require a combustion amount setting circuit at the start of combustion and aims at rationalizing the combustion amount setting circuit.

[0006]

In order to achieve the above object, the means of the combustion control device according to the present invention is a burner for heating air or water, and a control means for adjusting combustion fuel and air for the burner. A means for setting the heating temperature of the air or water to be heated by the burner and a detecting means, a combustion amount setting means for instructing the combustion amount of the burner at the start of combustion and at the time of steady combustion by a signal from the setting means and the detecting means A combustion amount setting circuit for outputting a drive signal of the control unit in response to an instruction signal of the amount setting unit, wherein the combustion amount setting unit selects and instructs the combustion amount at the start of combustion from the combustion amount at the steady combustion. It is characterized by.

[0007]

With the above-mentioned means, the combustion control device of the present invention is
The combustion amount setting means selects the combustion amount at the start of combustion from the combustion amounts set at the time of steady combustion by the signals of the temperature setting means and the detection means, and the combustion amount setting circuit at the start of combustion is not required. The rationalization of the setting circuit can be achieved.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment will be described below with reference to the drawings. 1 shows a range hood type water heater according to the present invention, in which 1 is a range hood type water heater main body, 2 is a heat exchanger, 3 is a fan motor as control means, 4 is a hot water tap, and 5 is Reference numeral 6 denotes a burner, 6 is a solenoid valve as control means, 7 is a water amount control motor, 8 is a proportional valve as control means, and I is an igniter for igniting the burner 5. On the front surface of the main body 1, a switch S1 for changing the hot water temperature as a setting means in five steps from 1 to 5 and a switch S2 for adjusting the ventilation air volume for changing the air volume of the fan motor 3 acting as a ventilation fan in three steps.
There is. When the control circuit C electrically connected to the proportional valve 8 and the like by a broken line in the drawing sets the switch S1 and opens the hot water tap 4, water flows through the water amount control motor 7 and the igniter I is activated. The solenoid valve 6 is opened, the proportional valve 8 is also opened, and the gas reaches the burner 5 to start combustion. Further, when the hot water tap 4 is opened, the fan motor 3 rotates strongly and supplies the combustion air required for the combustion of the burner 5. A sensor T for detecting the water temperature and the water amount is provided at the entrance and exit of the heat exchanger 2 as a detecting means.
_It also has a sensor T _H for detecting _W and hot water temperature.

FIG. 2 shows a control circuit C, 9 is a power plug, 10 is a relay for switching the speed of the fan motor 3, and 1 is a relay.
1 is a transformer, 12 is a microcomputer (hereinafter, also referred to as a microcomputer) as a combustion amount setting means, 13, 17,
22, 25, 26 are transistors, 14, 15, 16,
18, 19, 20, 21, 23, 23A and 27 are resistors,
Reference numeral 24 denotes an operational amplifier, and a portion surrounded by a chain line is a combustion amount setting circuit B.

Next, when the switches S1 and S2 are set and the setting signal is input to the control circuit C, the port Y of the microcomputer 12 outputs a signal L as a preliminary operation immediately before the start of combustion, and the transistor 22 is turned on. Then, of the operational amplifier 24 +
The voltage specified by the resistors 23 and 23A is applied to the terminals.
The operational amplifier 24 outputs a current from its − terminal to a resistor 27 provided in the current path of the proportional valve 8 so as to have the same voltage as the voltage applied to the + terminal, and the resistor 23,
A constant current defined by 23 A is passed. Then, the proportional valve 8 changes and adjusts the gas amount according to this constant current. Further, even if the valve portion (not shown) of the proportional valve 8 is stuck to the transistor 22 by leaving it in a closed state for a long period of time, a large current is forcibly preliminarily opened to release it. At this time, the transistors 13 and 17 are off, the solenoid valve 6 is also closed, and gas is not supplied to the burner 5.

After the preparatory operation, the microcomputer 12 stops outputting the signal L of the port Y, the port X outputs the signal L and the port Z outputs the signal H, and the transistor 22 is turned off to turn on the transistors 13 and 17. Turn on. Resistor 15 and resistor 20
Is the same value and is sufficiently larger than the resistance value for each voltage division, and the voltage divided by the resistors 14 and 16 and the voltage divided by the resistors 18, 19 and 21 are applied to the + terminal of the operational amplifier 24. The average value of the applied voltage is applied. This average voltage makes the voltage of the resistor 27 connected to the negative terminal of the operational amplifier equal. The current of the proportional valve 8 that determines the gas flow rate as the gas combustion amount at the start of combustion is based on the criteria of facilitating ignition and obtaining good ignition performance such as low ignition noise, and at the time of steady combustion described later. It is determined with other criteria as a match with the corresponding gas flow rate selected from the combustion amount of. A "medium" combustion amount, which will be described later, is selected as the gas flow rate, the ignition is performed by the igniter I to end the ignition operation, and then the steady combustion operation is started.

In order to obtain the desired hot water temperature, the steady combustion operation is
Instruction of the microcomputer 12 corresponding to the setting signal of the switch S1
The gas combustion amount is three levels: “strong”, “medium”, and “weak”
Is switched to. First, the microcomputer 12 is "weak"
Port X and port Y output signal H, and port Z outputs signal L
The transistor 22 and the transistor 13 and
The transistor 17 turns off, and the current of the proportional valve 8 becomes 1
It is determined to be minimum by 8, resistor 19 and resistor 21. Next
As for "strong", only the port X of the microcomputer 12 receives the signal L.
To turn on only the transistor 13,
-Terminal of loop 24 is higher than the voltage value when "weak"
It is set and the current of the proportional valve 8 is set to the maximum. further
The "medium" gas flow rate is from ports X and Z of the microcomputer 12.
Signals L and H are output, and transistors 13 and 17 are
When turned on and the negative terminal of operational amplifier 24 is "strong"
To lower the voltage a little with the resistor 16 than the voltage value of
Become. Then, the combustion amount setting circuit set at "medium"
The circuit configuration of B is the same as the circuit configuration at the start of combustion.
It The fan motor 3 has a "strong" gas combustion amount,
For "medium" and "weak" settings and switch S2 setting signals
Correspondingly, the relay 10 is turned off by the instruction signal of the microcomputer 12.
Replaced with combustion air and ventilation air (in the figure, the white arrow
(Shown) is changed, but detailed description is omitted.
It was Also, the sensor T_W, T _HIs detected when hot water is supplied to hot water tap 4.
The signal is input to the microcomputer 12, and the hot water supply load of the microcomputer 12
Water volume control with water volume control motor 7 and gas combustion
Automatically corrects the setting error of the amount and sets the microcomputer 12
When the signal is received, the input signal for the selection calculation of the gas combustion amount is also supplied.
ing.

In the case of a heating appliance that has a stepless proportional control function of the gas flow rate and the combustion air amount, the gas combustion amount should be set to an appropriate ignition combustion range according to the ignition characteristics peculiar to the water heater. It is also possible to determine and set a plurality of combustion amount points during this period and set the optimum ignition combustion amount at any time in response to the setting signal and the detection signal.

[0014]

As described above, the combustion control device of the present invention has a combustion amount setting circuit for ignition by selecting the combustion amount at the start of combustion (at the time of ignition) from the combustion amount for controlling the steady combustion. It can be expected to streamline the combustion amount setting circuit by making it unnecessary.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a combustion control device according to the present invention.

FIG. 2 is a control circuit diagram of the same.

[Explanation of symbols]

3 Fan motor 5 Burner 8 Proportional valve 12 Microcomputer S1, S2 switch T _W , T _H sensor B Combustion amount setting circuit

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Naoki Otani 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1. A burner for heating air or water, a control means for adjusting fuel and air for burning the burner, setting means and detecting means for setting a heating temperature of air or water heated by the burner, and setting means and detection. A combustion amount setting means for instructing the combustion amount of the burner at the start of combustion and a steady combustion by the signal of the means, and a combustion amount setting circuit for outputting the drive signal of the control means by the instruction signal of the combustion amount setting means are provided. The combustion control device, wherein the setting means selects and instructs the combustion amount at the start of combustion from the combustion amount at the steady combustion.