JPS6126762Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a control device for a combustion machine, and is particularly intended to avoid unexpected situations such as explosion and ignition.

Some conventional combustion control devices perform the following operations.

That is, when the main switch is closed, the timer is activated, the first relay is activated synchronously, and the ignition device is discharged for a predetermined period of time. Then, upon detecting this discharge, the second relay operates, and the fuel supply solenoid valve operates to supply fuel.

As explained above, this combustion control device starts fuel supply after confirming the discharge of the ignition device to prevent explosion and ignition, but since the relay operates with a delay, It was not sufficient to prevent explosion and ignition.

This means that, for example, if the ignition starts discharging just before the end of the timer operation, and then the timer operation stops immediately, the first relay contact opens with a delay and stops the discharging operation, but on the other hand, the ignition discharge is detected. Therefore, if the second relay contact closes after the first relay contact opens, fuel will be supplied from the fuel supply solenoid valve to the combustor, and the next ignition will be delayed. There was a risk of explosion and ignition during operation.

The present invention has been developed in view of the above points, and is intended to solve the above conventional problems by supplying fuel when the operation of the ignition device and the discharge of the ignition device are simultaneously detected. It is.

Hereinafter, one embodiment of the present invention will be described based on the drawings.

In the figure, 1 is the commercial power supply, 2 is the main switch,
3 is the electric motor of the blower that supplies combustion air; 4 is the wind pressure switch that is closed when it detects that the electric motor 3 is driving and blowing air; and 5 and 6 are the main switch 2 and the wind pressure switch 4 that are closed. 7 is a rectifier consisting of a low-voltage diode bridge that rectifies the alternating current obtained through the step-down transformer 6, 8 is a smoothing capacitor, and 9 is an ignition discharge operating time. Regulating ignition timer,
10 is a first relay that is energized when the ignition timer 9 is activated, 11 is a smoothing capacitor, 12 is an ignition device to which the DC voltage obtained by the rectifier 5 is applied, and 13 is closed when the first relay 10 is energized. a first relay contact that opens when de-energized;
14 is an ignition electrode, 15 is an ignition discharge detection circuit that detects the discharge operation of the ignition device 12 and outputs a signal, and 16 is a signal from the discharge detection circuit 15 and an ignition timer 9.
A condensed flame current generation circuit as an AND circuit that outputs a signal when the activation signal and the activation signal are input simultaneously, 1
7 is a solenoid valve for fuel supply; 18 is a thyristor as a semiconductor switching element connected in series to the solenoid valve 17; its gate is connected between resistors 19 and 20 connected in parallel to the ignition device 12; There is. 21 is a flame detection electrode; 22 is a flame detection circuit that outputs a signal when either the signal from the analogous flame current generation circuit 16 or the signal from the flame detection electrode 21 is input; and 23 is a flame detection circuit. A second relay 24 is energized when receiving a signal from the circuit 22. A second relay 24 is a second relay contact that closes when the second relay 23 is energized and opens when it is not energized. interposed between.

In the combustion control device having such a configuration, the main switch 2
When closed, the electric motor 3 is driven to supply combustion air. When the supplied combustion air reaches a predetermined wind pressure, the wind pressure switch 4 closes and the rectifier 5
and transformer 6 are activated. At the same time, the ignition timer 9 is activated and the first relay 10 is energized. Then, the first relay contact 13 closes, the ignition device 12 causes a discharge operation, and the ignition discharge detection circuit 15 detects the discharge operation via the ignition electrode 14.
If the ignition timer 9 continues to operate, this operating signal and the discharge detection circuit 1
Simultaneously receiving the signal from 5, the condensed flame current generation circuit 16 outputs a signal, and the second relay is energized via the flame detection circuit 22. This closes the second relay contact 24 and connects the solenoid valve 17 and thyristor 18 to the rectifier 5. At this time, if the first relay contact 13 is closed, the gate signal of the thyristor 18 will flow through the resistor 20, and the thyristor 18 will be fired.
The solenoid valve 17 is energized, fuel is supplied and ignited. After normal ignition, the signal from the flame detection electrode 21 is input to the flame detection circuit 22 even if the ignition timer 9 stops operating and no signal is output from the simulated flame current generation circuit 16. Therefore, the second relay 23 maintains an excited state, and its second relay contact 24 is closed. Therefore, the ignition timer 9 stops operating,
Even if the contact 13 of the first relay 10 is opened and no signal flows to the gate of the thyristor 18, the holding current continues to flow through the thyristor 18, and therefore the solenoid valve 17 maintains its energized state. That is, as long as the flame current flows through the flame detection electrode 21, the supply of combustion is maintained.

On the other hand, if there is some abnormality in the ignition device and it starts discharging just before the ignition timer 9 ends, and immediately after that, the ignition timer 9 ends and the ignition does not ignite normally.
Thyristor 18 becomes non-conducting, solenoid valve 17 closes, and fuel supply is stopped.

Therefore, fuel is supplied only when the discharge detection signal and the signal when voltage is applied to the ignition device 12 are simultaneously detected.
Even if the first relay 10 and the second relay 23 operate with a delay, explosion and ignition can be reliably prevented.

As explained above, according to the present invention, by supplying fuel when the operation of the ignition device and the discharge of the ignition device are simultaneously detected, even if the relay that controls the operation is activated with a delay, This is highly effective in terms of safety because explosion and ignition can be reliably prevented.

[Brief explanation of the drawing]

The figure shows a combustion control device that is an embodiment of the present invention. 9...Ignition timer, 10...1st
Relay, 12...Ignition device, 13...
First relay contact, 14...Ignition electrode,
15...Ignition discharge detection circuit, 16...
Simulated flame current generation circuit, 17... Solenoid valve, 18... Thyristor (semiconductor switching element), 22... Flame detection circuit, 23... Second relay, 24... Second relay contact.

Claims (1)

[Scope of utility model registration request] an ignition timer that regulates the discharge operation time; a first relay that operates in synchronization with the timer;
an ignition device that discharges when the first relay is activated; an AND circuit that activates if both the first relay activation signal and the ignition device discharge signal are detected; and the AND circuit and the combustion flame that are detected. A flame detection circuit that is activated by the output of at least one of the flame detection electrodes that outputs current, a second relay that is activated by the output of this flame detection circuit, and a semiconductor switching element that is inserted into the power supply circuit of the fuel supply valve. and a relay contact of the second relay is inserted into the power supply circuit of the fuel supply valve, and the semiconductor switching element conducts when the relay contact of the first relay is closed and opens the relay contact. A combustion control device characterized in that it is configured to be maintained in a conductive state regardless of the situation.