JPH0335958Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to an improvement of a combustion control device used in a domestic open combustion heater.

Conventional technology Conventionally, in a liquid fuel combustion control device in which a pump pumps liquid fuel to a heated vaporizer, gasifies it in the vaporizer, and injects the vaporized gas from a nozzle to a Bunsen burner, manual operation is required. During the extinguishing process, the pump was stopped and a needle valve was used to instantly stop the ejection of vaporized gas from the nozzle to extinguish the fire.

Problems to be solved by the present invention In the conventional liquid fuel combustion control device as described above, the pump stops and the needle valve operates at the same time, so when a fire is extinguished, the vaporized gas that is the fuel stops instantly. Due to the ejector effect caused by the ejection energy of vaporized gas, the primary combustion air that had flowed into the burner flows into the burner due to inertia even after the ejection of vaporized gas has stopped, and the mixture in the burner becomes fuel lean. The lift extinguished the fire at the flame hole, and the unburnt mixture was released into the room with an odor.

Means for Solving the Problems The present invention has been made to overcome the above drawbacks, and includes a flame detection circuit that detects the relationship between the flame level and a predetermined level value, and a signal that is generated by a stop operation. The generated operation switch circuit and each independently input to the control means (hereinafter referred to as microcomputer), and the output thereof to the circuit for driving the pump and the circuit for driving the needle valve, respectively. Immediately after the operation stop signal is input to the microcomputer, the pump is controlled to stop, and then the needle valve is controlled to stop for a certain period of time T or when the flame level becomes below a predetermined value, whichever comes first. It has a driving function.

Function Normally, a stop instruction signal is input from the operation switch circuit to the microcomputer to stop the pump, and then the pump is stopped for a certain period of time T.
Within this time, the unburned mixture will burn out on the burner and the flame will disappear. Therefore, by driving the needle valve after this, the odor at the time of extinguishing the fire can be reduced without leaving any unburned air-fuel mixture. On the other hand, if there is a large amount of unburned air-fuel mixture after the pump has stopped, the flame will be difficult to extinguish.In this case, from the standpoint of danger prevention, the needle valve can be driven for a certain period of time T to instantly extinguish the flame. In this case as well, the amount of unburned air-fuel mixture is reduced compared to when the pump is stopped and the needle valve is driven at the same time, and the odor can be reduced.

Embodiment Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a structural diagram of the combustion controller according to this embodiment.
FIG. 2 is a control circuit diagram according to the present embodiment, FIG. 3 is a control timing chart according to the present embodiment, and FIG. 4 is a flow chart of the microcomputer according to the present embodiment.

In FIG. 1, 1 is a pump whose suction port is connected to liquid fuel 4 in an oil pan 3 via an oil feed pipe 2, and whose discharge port is connected to a vaporizer 6 via an oil feed pipe 5. It is. The vaporizer 6 is the heater 7
and is connected to a nozzle 9 through a communication pipe 8. Reference numeral 10 denotes a needle valve, which is provided inside the nozzle 9, moves from side to side within the nozzle 9 by a solenoid 11 provided outside the nozzle 9, and blocks the spout 13 of the nozzle 9 with a pointed head formed at one end. At the same time, the other end 14 closes a pressure relief pipe 15 connected to the nozzle 9. 17 is a frome rod located above the burner, and rod 17
The flame level is detected by

In addition, in Fig. 2, 16 is a DC power supply, and A
is a flame detection circuit, B is an operation switch circuit, C is a pump drive circuit, and D is a needle valve drive circuit. The flame detection circuit A applies an AC signal between the rod 17 and the burner, and when the DC signal rectified by the flame is larger than a preset predetermined value, that is, when there is a flame, the output is "H", and the output is lower than the predetermined value. When this happens, the output is "L", and this signal is applied to the input 20 of the microcomputer 19. In the operation switch circuit B, 21 is an operation switch, 22 is a resistor, and the operation switch 21 is short-circuited during operation and open when stopped, and this signal is applied to the input 23 of the microcomputer 19. That is, the input 23 is "H" during operation and "L" when stopped.
In the pump drive circuit C, 24 is a resistor, 25 is a transistor, and 26 is a relay. This circuit is operated by the signal of the output 27 of the microcomputer 19, and when the output 27 is "H", the transistor 25,
When the relay 26 is both turned on and the output 27 is "L", the transistor 25 and the relay 26 are both turned off. The contacts of the relay 26 control the energization of the pump 1,
When the relay 26 is turned on, the pump 1 is energized and operates. 28 in the needle valve drive circuit D is a resistor, 2
9 is a transistor, and 30 is a relay. This circuit is operated by the signal of the output 31 of the microcomputer 19. When the output 31 is "H", the transistor 29 and the relay 30 are both turned on, and when the output 31 is "L", the transistor 29 and the relay 30 are turned on. Transistor 29 and relay 30 are both turned off. The contacts of the relay 30 control the solenoid 11 and, via this, the needle valve 10.
In other words, when relay 30 turns off, solenoid 1
1 is turned on, and the needle valve 10 opens the spout 13.

Next, the operation of this embodiment will be described.

In FIG. 3A, for example, when the user instructs the pump 1 to stop using an operation switch (not shown) to stop the operation, the microcomputer 19 sets its output section 27 to "L" and turns off the reel 26, thereby stopping the pump 1. As a result, the supply of kerosene to the vaporizer 6 is stopped. At the same time, the microcomputer 19 starts counting a certain period of time T. At this stage, the solenoid 11 is off and the needle valve 10 opens the spout 13, so the residual vaporized gas inside the carburetor 6 is released from the spout 13.
Discharge more and burn it up with a burner. Fixed time T
When the vaporized gas decreases within a certain period of time and the flame detection level decreases to below a predetermined value, the output of the flame detection circuit A,
The input 20 of the microcomputer 19 changes from "H" to "L". At this stage, the output 31 changes from "L" to "H" and the transistor 29 and relay 30
The solenoid 11 is turned on, and the needle valve 10 is turned on.
Since this blocks the spout 13, the amount of unburned air-fuel mixture becomes extremely small, and the odor emitted into the room is reduced.

On the other hand, as shown in Fig. 3b, when there is a large amount of unburned air-fuel mixture when the operation is stopped and the flame does not disappear within a certain period of time T and the input 20 of the microcomputer 19 remains at "H", after the certain period of time T has elapsed. Output 31 is “L”
to "H" and close the jet nozzle 13 in the same way as described above, so that the amount of unburned air-fuel mixture is reduced and the odor emitted into the room is reduced.

Effects of the Device As described above, according to the present invention, the nozzle is blocked when the flame drops below a predetermined value or after a certain period of time, whichever comes first, so the unburned mixture that remains when the operation is stopped. It is low in air and will not be emitted into the room with any odor.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram of a liquid fuel combustion control device according to an embodiment of the present invention, FIG. 2 is a control circuit diagram thereof, and FIGS. 3 a and 3 are control timing charts between each component.
FIG. 4 shows a flow chart of the control means. A...flame detection circuit, B...operation switch circuit,
C...Pump drive circuit, D...Needle valve drive circuit, 19...Control means (microcomputer),
T...a certain amount of time.

Claims (1)

[Scope of utility model registration request] The liquid fuel is forced into the heated vaporizer by the oil pump, and the vaporized gas gasified in the vaporizer is ejected from the nozzle nozzle and burned by the burner. At the same time, a needle valve that closes the nozzle is inserted into the nozzle. In the liquid fuel combustion control device installed in the pump, there is provided a flame detection circuit A that detects the relationship between the level of combustion flame and a predetermined value of a preset level, an operation switch circuit B that generates a signal according to an operation to stop operation, and the pump. It has a pump drive circuit C that drives the needle valve, a needle valve drive circuit D that drives the needle valve, and a control means 19, and the flame detection circuit A and the operation switch circuit B are connected to the input of the control means 19, and the pump drive circuit is connected to the output of the control means 19. C and needle valve drive circuit D are connected, and immediately after the operation stop signal is input from the operation switch circuit B to the control means 19, an arbitrary fixed time T is counted after outputting the signal to the pump drive circuit C to stop the pump. In addition, the needle valve drive circuit D is activated when the operation stop signal is input and the after-flame detection circuit A causes the flame to fall below the predetermined value or a certain period of time T, whichever is earlier. A liquid fuel combustion control device characterized by having a function to output as much as possible.