JPH0468215A - Combustion control device - Google Patents

Abstract

PURPOSE:To prohibit any combustion in the event that a connector connection is not sufficient by a method wherein a combustion control device is provided with a combustion control means for controlling combustion at a burner in response to an output voltage of a voltage generating circuit and a safety control means for enabling combustion at the burner when the output voltage is less than a reference value. CONSTITUTION:Resistance values of resistors 29 to 33 in a small circuit board 41 are varied in response to the type of gas or maximum combustion amount and minimum combustion amount of an applied combustion device to generate different voltages at intermediate connection points 34 to 38 of a voltage generating circuit 17. Combustion control data corresponding to a voltage are stored in a micro-computer 12 to perform a combustion control. A small circuit board 41 is connected to a large circuit board 42 through connectors 39 and 40. Conversion of gas type or changing-over of capability can be easily performed. When connection of the connectors 39 and 40 is not satisfactory, digital values corresponding to the voltages of the intermediate connection points 34 to 38 of the voltage generating circuit 17 exceed their reference values and combustion can be prohibited by the micro-computer 12 also acting as a combustion control means and a safety control means and a safety can be sufficiently assured so as not to cause any abnormal combustion in response to the erroneous combustion control data.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application This invention relates to a combustion control device used in fan heaters and water heaters that use gas, kerosene, etc. as fuel.

(b) Prior art In this type of combustion control device, for example,
As disclosed in the publication, a voltage generation circuit consisting of a plurality of resistors is provided on the input side of a microcomputer, and by changing the resistance value of one resistor of the voltage generation circuit, different voltages are generated. is input into a microcomputer. This voltage is then converted into a digital value inside the microcomputer,
It is used as data to control combustion in the burner.

In addition, in gas fan heaters and gas water heaters, by changing the resistance value of the voltage generating circuit's resistance depending on the gas type and generating different voltages, the maximum and minimum combustion amounts in the burner can be adjusted to match the gas type. That's what I do.

(c) Problems to be solved by the invention By the way, when the type of gas used in the combustion device changes due to moving house, etc., or when the combustion control device is used in common with combustion devices with different combustion amounts, the voltage generation circuit It is very convenient to connect at least one of the resistors to other circuit components of the voltage generating circuit by means of a connector so that at least one of the resistors can be easily replaced. However, if the connector connection is insufficient, there is a risk that the correct voltage will not be input from the voltage generation circuit to the combustion control means such as a microcomputer, resulting in abnormal combustion.

This invention was made in view of the above facts,
The purpose is to allow combustion control data to be easily changed by replacing at least one resistor in the voltage generation circuit with a connector, and to prevent combustion from occurring if the connector connection is insufficient. do.

(d) Means for Solving the Problems The present invention includes a voltage generating circuit in which at least one resistor and other circuit components are connected through a connector, and a voltage generating circuit in a burner based on the output voltage of this voltage generating circuit. The structure includes a combustion control means that controls combustion, and a safety control means that compares the output voltage with a predetermined reference value and enables combustion in the burner when this voltage is within the reference value. .

(E) When at least one resistor of the operating voltage generation circuit is replaced with a connector, the voltage that can be input from the voltage generation circuit to the combustion control means changes, and the combustion control means controls combustion in the burner based on this voltage. Therefore, combustion control data such as combustion amount depending on the gas type can be easily changed.
If the connector connection is insufficient, the output voltage of the voltage generating circuit will deviate from the reference value, so combustion will not occur due to the safety control means, and abnormal combustion will be prevented.

(F) Example Hereinafter, an example in which the present invention is applied to a gas fan heater will be described.

FIG. 4 shows a gas fan heater.

In Figure 4, (1) has an air filter (
(4) is a combustion chamber provided in the upper part of the exterior case (1); 5) is a gas burner installed in the combustion chamber (4), and (6) is the combustion chamber (4).
A convection fan consisting of a cross flow fan installed below, (7) is a cover plate that covers the top and front surface of the combustion chamber (4), and (8) is a cover plate that covers the top and front surface of the combustion chamber (4). A ventilation passageway is interposed between the air intake port (2) and the combustion chamber (4) to guide the air flowing in from the suction port (2) and the combustion gas from the combustion chamber (4) to the convection fan (6). A fan casing that leads to the warm air outlet (3), (10) an automatic cord reel device installed in the lower space of the exterior case (1) partitioned by the fan casing (9), (11) is the power cord.

FIG. 1 shows the combustion control device for the gas fan heater mentioned above. In Fig. 1, (12) is a microcomputer (hereinafter referred to as microcomputer), and the input side of this microcomputer (12) includes an operation switch (13), a temperature setting device (14), a room temperature sensor (15), a frame A rod (16) and a voltage generating circuit (17) are provided, and a former solenoid valve (18) and a proportional valve (
19), an igniter (20), a convection fan <6) and a digital display (21).

The voltage generation circuit (17) consists of two resistor groups (RA) (RB
), and the resistors (24) to (28) and the resistors (29) to (33) of these resistor groups are connected in series, respectively. Further, intermediate connection points (34) to 38) are connected to input ports (11) to (15) of the microcomputer (12). In addition, the resistor group (RB) is connected to the connector (39) (4
0) to the resistor group (RA) and ground (23). That is, as shown in Figure 2, the resistance group (
RB) and the connector (39) are provided on the small board (41). In addition, a microcomputer (12), a resistance group (RA),
and other circuit components and the connector (40) are the large board (
42). And the female connector (3
9) into the male connector (40), the resistor group (RB) is connected to other circuit components of the voltage generating circuit (17).

As shown in Figure 3, the microcomputer (12) performs initial processing when the power is turned on, and at this time input ports (11) to (I
5) A/D convert the voltage into a digital value. These digital values (2 digits in hexadecimal) are the reference value (FO).
Determine whether the following is true. The voltage at the intermediate connection point (34) or 38> of the voltage generation circuit (17) is determined by the microcomputer (
12) The connector (39) (
If the connection of 40> is sufficient, the digital value becomes (FO
) becomes the smaller value. In this case, the microcomputer (12) converts the digital values corresponding to the voltages at each intermediate connection point (34) to (38) into combustion control data (the maximum current value of the proportional valve (19), the minimum current value of the proportional valve (19)). , frame rod (16
) is stored as a flow value, the maximum rotation speed of the convection fan (6), and the minimum rotation speed of the convection fan (6).

When the operation switch (13) is turned on, the microcomputer (12)
), open the original solenoid valve (18) and proportional valve (19),
While supplying gas fuel to the gas burner (5), the igniter (20) and convection fan (6) are activated to allow the gas burner (5) to start combustion. A portion of the indoor air sucked into the exterior case (1) from the suction port (2) by the convection fan (6) enters the combustion chamber (4>) through the intake port (4A), and air for combustion It can be used as
After the combustion gas in the combustion chamber (4) is discharged from the exhaust port (4B), the air in the ventilation passage (8) that cools the outer wall of the combustion chamber (4) and the upper and front portions of the outer case (1) are released. The air from the cooling air passage (43) joins with the convection fan (6).
) can be inhaled completely. The hot air discharged from the convection fan (6) is guided to the hot air outlet (3) along the fan casing (9) and is discharged indoors.

During such heating operation, the microcomputer (12) monitors the temperature completely set by the temperature setting device (14) and the room temperature sensor (15).
) is determined, and the current (valve opening degree) of the proportional valve (19) and the rotation speed of the convection fan (6) are linearly controlled according to the temperature difference. That is, when the temperature difference is large, the maximum current is sent to the proportional valve (19) based on the combustion control data mentioned above, and the convection fan (6) is allowed to operate at the maximum rotation speed, thereby maximizing combustion in the gas burner (5). do. In addition, as the room temperature rises, combustion in the gas burner (5) is throttled, and when the temperature difference becomes smaller, a minimum current is passed through the proportional valve (19) and the rotation speed of the convection fan (6> is minimized). In addition, the current value of the flame rod (16) and the flameout current value are compared to monitor the combustion state and the oxygen concentration in the room. Then, when the operation switch (13) is turned off, combustion is stopped and the heating operation is ended.

In the unlikely event that the connectors (39) and (40) are not sufficiently connected, all or part of the digital values corresponding to the voltages at the intermediate connection points (34) to (38) exceed [FO].

For this reason, the microcomputer (12) is connected to the digital display (21).
to display an error display so that combustion does not occur even if the operation switch (13) is turned on. In such a case,
- Once the power is turned off and the connectors (39) and (40) are properly connected, operation is possible.

According to this embodiment, the resistors (29) to (
By changing the resistance value of the voltage generating circuit (1) according to the gas type and the maximum and minimum combustion amount of the model used
Different voltages can be generated at the intermediate connection points (34) to (38) of 7), and combustion control data corresponding to these voltages can be stored in the microcomputer (12) to perform combustion control. J＼ Connect the board (41) to the connector (39) (
40) to the large board (42), gas type conversion and capacity switching can be easily performed.

Also, if the connections of the connectors (39) and (40) are not sufficient, the intermediate connection points (34) to (3) of the voltage generation circuit (17)
8), the digital value corresponding to the voltage exceeds the reference value, and the microcomputer (12), which also serves as combustion control means and safety control means, prevents combustion from occurring, and abnormal combustion occurs based on incorrect combustion control data. It is possible to sufficiently ensure safety, such as not having to worry about being attacked.

(G) Effects of the Invention Since this invention is configured as described above, combustion control data can be easily changed by simply replacing the resistor with a connector, and gas type conversion in a gas combustion device or combustion control device It is not only a scale that is very convenient for common use with combustion devices of different capacities, but also has excellent usability and safety, such as being able to prevent abnormal combustion when the connector is not connected properly.

[Brief explanation of drawings]

The figures relate to an embodiment in which the combustion control device of the present invention is applied to a gas fan heater, and FIG. 1 is a schematic configuration diagram of the combustion control device, FIG. 2 is an explanatory diagram of the main parts of the combustion control device, and FIG. 3 is a diagram showing the main parts of the combustion control device. 4 is a flowchart for explaining the operation of the microcomputer, and FIG. 4 is a schematic configuration diagram of the gas fan heater. (5)...Gas burner, (12)...Microcomputer serving as combustion control means and safety control means, (
17)... Voltage generation circuit, (29) to (33)...
・Resistance, (39) (40)...Connector.

Claims (1)

[Claims] (1) A voltage generation circuit in which at least one resistor and other circuit components are connected via a connector, a combustion control means for controlling combustion in a burner based on the output voltage of the voltage generation circuit, and the output of the voltage generation circuit. A combustion control device comprising a safety control means that compares a voltage with a predetermined reference value and enables combustion in a burner when the voltage is within the reference value.