JP2903951B2 - Liquid fuel supply device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid fuel supply system for supplying fuel to a combustion section such as an oil fan heater.

[0002]

2. Description of the Related Art FIG.
The electromagnetic pump 102 is disposed above the tank 101 holding the liquid fuel as shown in FIG. 1, and the electromagnetic pump 102 sucks up the liquid fuel in the tank 101 and supplies it to the combustion unit 104 via the oil supply pipe 103 to be burned. It has become.

The electromagnetic pump drives a discharge valve 106 and a suction valve 107 in accordance with the vertical movement of a plunger 105 as shown in FIG. 8 to suck fuel from a tank 101 and supply it to a combustion section 104. ing.

[0004]

However, in the above conventional configuration, the oil pump 10 is driven by the electromagnetic pump 102.
The liquid fuel supplied to the combustion unit 104 via the fuel pump 3 is connected to the oil supply pipe 103 even when the electromagnetic pump 102 is stopped, and the vaporization unit 10 of the combustion unit 104 as shown in FIG.
Due to a rise in the temperature of the nozzle 109 or the like facing the inside of the nozzle 8, the fuel at the tip of the nozzle expands and drops and is supplied to the combustion unit 104.

[0005] For example, during combustion, the oil feed pipe 103 and the nozzle 109 near the combustion section 104 are hot,
The oil feed pipe 103 and the nozzle 109 are cooled by the liquid fuel in the tank 101 sucked and supplied by the electromagnetic pump 102. However, when the combustion is stopped and the supply of the liquid fuel is stopped, the cooling effect by the liquid fuel is lost, the temperature of the liquid fuel rises in the oil supply pipe 103 and the nozzle 109, and the amount of the expanded oil slightly increases in the combustion unit 104. Supplied late. The supplied expanded oil amount is
It is vaporized in the vaporization section 108 of the combustion section 104 and causes a large amount of unburned gas, a strong odor, and tar generation.

[0006] This phenomenon appears remarkably when the temperature of the oil supply pipe 103 and the nozzle 109 rises most immediately after the stop of the electromagnetic pump, giving the user discomfort.

Accordingly, the applicant has provided a solenoid for forcibly opening the discharge valve in the electromagnetic pump, and continuously turning on the solenoid for a predetermined time after extinguishing the fire to open the discharge valve, thereby discharging the liquid fuel at the tip of the nozzle. We considered a liquid fuel supply device that returns to the tank by the difference in oil level head. However, with this method, the plunger and the discharge valve at the time of fire extinguishing may momentarily push out a part of the liquid fuel, and as a whole the odor is reduced, but the odor is temporarily left. Was.

The present invention solves the above-mentioned problem, and eliminates the pushing of fuel due to the movement of a plunger during fire extinguishing.
The purpose is to reduce odor and tar production.

[0009]

In order to achieve the above object, the present invention provides a tank for holding a liquid fuel, a plunger for sucking the fuel from the tank and supplying the fuel to a combustion section, and a solenoid for driving the plunger. A discharge valve provided on the downstream side of the plunger, an electromagnetic pump having a discharge solenoid for opening and driving the discharge valve, a pump drive control unit for controlling energization of the solenoid to drive the plunger, and A discharge solenoid drive control unit that opens the discharge valve by energizing the solenoid, and the discharge solenoid drive control unit opens the discharge valve by energizing the discharge solenoid a predetermined time after the pump drive control unit stops energizing the solenoid. There is a configuration to do.

[0010]

According to the present invention, since the discharge valve opens after the movement of the plunger is stopped and the internal pressure of the pump is reliably reduced, the liquid fuel is not pushed out from the nozzle toward the combustion section by the internal pressure of the pump. As a result, generation of unburned gas, severe odor, and tar generation can be reliably prevented.

[0011]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First, in FIG. 2, reference numeral 1 denotes a main body case, and 2 denotes a tank for holding liquid fuel disposed on a side portion of the main body case 1, and a detachable cartridge tank 3 is disposed on the upper part thereof. 4 is an electromagnetic pump disposed on the upper surface of the tank 2,
Numeral 5 is an oil feed pipe, and 6 is a combustion section which vaporizes and burns liquid fuel supplied through the oil feed pipe 5 by the electromagnetic pump 4 and has the same configuration as the conventional one shown in FIG. A combustion cylinder 7 for guiding the combustion exhaust gas upward is provided around the periphery. Numeral 9 is a duct for mixing the indoor air flow from the convection blower 8 disposed behind and covering the combustion tube 7 with the above-mentioned combustion exhaust gas to generate hot air.

Next, an electromagnetic pump for supplying a liquid fuel will be described. In FIG.
A discharge connection portion 11 for connecting the oil feed pipe 5 is connected to a distal end of the pipe, which forms a flow path for the liquid fuel. Reference numeral 12 denotes a discharge valve seat provided in the discharge coupling portion 11 and has a discharge port 12a. Reference numeral 13 denotes a discharge valve which opens and closes the discharge port 12a, which is made of a magnetic material, opens when discharging liquid fuel, and closes when discharging by a discharge spring. Reference numeral 15 denotes a discharge solenoid disposed around the discharge coupling portion 11 near the discharge valve 13 for opening and closing the discharge valve 13. The discharge solenoid 15 transmits magnetic lines of force from the discharge solenoid 15 to the discharge coupling portion 11. An upper discharge magnetic path 16 for lifting and opening the upper part 13 and a lower discharge magnetic path 17 for transmitting magnetic lines of force are provided below the lower discharge magnetic path 16.

A plunger 18 is located below the discharge valve seat 12 and moves up and down.
9 is opened and liquid fuel is sucked between the discharge valve seat 12 and the suction valve portion 21 for closing the suction valve 19 and pushing the liquid fuel upward by a suction spring 20 when moving upward. And are supported by springs 22 and 23. Reference numeral 24 denotes a solenoid disposed around the pipe post 10, and the plunger 1
The upper magnetic path 25 for transmitting the magnetic lines of force from the solenoid 24 to the tube column 10 and raising the plunger portion 18 upward, and the lower magnetic path 26 for separating and transmitting the magnetic lines of force to the lower part thereof. It is arranged. 27 is the column 10
A suction filter disposed at the lower end of the filter 28 filters the dust at the lower end thereof so as not to enter the filter.
Is attached.

Reference numeral 30 denotes a pump drive control unit for controlling the energization of the solenoid 24 for the plunger 18, and reference numeral 30a denotes a solenoid drive control unit for controlling the energization of the discharge solenoid 15, as shown in FIG. It operates by receiving the output from. The combustion control unit 31 operates based on an operation start command from the operation switch 32, and controls the pump drive control unit 30 and the discharge solenoid drive control unit 30a according to a predetermined program.

In the above construction, first, fuel is supplied from the cartridge tank 3 into the tank 2 so as to maintain a constant oil level, and is sucked from the tank 2 by the electromagnetic pump 4 to the combustion section 6 via the oil feed pipe 5. Supplied. Then, the gas is burned in the combustion section 6, and the flue gas flows upward through the combustion cylinder 7, is mixed with the indoor air flow from the convection blower 8 in the duct 9, is discharged as warm air, and is used for heating.

Next, the supply of the liquid fuel will be described.
When a combustion start command is issued from the combustion control unit 31, the solenoid 24 for plunger is energized and driven to start combustion as shown in the flowchart of FIG. That is, when the solenoid 24 is energized, a magnetic field is generated from the solenoid 24 via the upper magnetic path 25 to the plunger 18, the lower magnetic path 26, and the solenoid 24, and the plunger 18 is pulled upward. At this time, the discharge valve 13 is opened, the suction valve 19 is closed, and the liquid fuel in the space between the discharge valve seat 12 and the plunger 18 is connected to the discharge connection portion 11 through the discharge port 12a of the discharge valve seat 12. Discharge to oil feed pipe 5. When the energization of the solenoid 24 is stopped, the plunger 18 is lowered to the original position by the springs 22 and 23. At this time, the discharge valve 13 is closed, the suction valve 19 is opened, and the space between the discharge valve seat 12 and the plunger 18 is filled with the liquid fuel sucked from the lower suction pipe 27.
The liquid fuel in the tank 2 passes through the filter 28, is sucked from the suction pipe 27, and is supplied to the combustion unit 6 via the oil supply pipe 5 by repeating ON / OFF of the current supply to the solenoid 24.

Next, when there is a command to stop the combustion, the power supply to the plunger solenoid 24 is stopped, and a predetermined time A
(Several hundred milliseconds) After a predetermined time B to the discharge solenoid 15
The power is supplied (for several seconds), and the discharge valve 13 is opened. That is, after a predetermined time A (several hundred milliseconds) after the power supply to the plunger solenoid 24 is stopped, power is supplied to the discharge solenoid 15 for a predetermined time B (several seconds) and the movement of the plunger 18 is stopped. The discharge valve 13 is opened. Therefore, when the discharge valve 13 is opened, the plunger 18 does not move and the liquid fuel is not pushed out from the nozzle tip. That is, as shown in FIG. 5, the predetermined time A from the combustion stop command to the energization of the discharge solenoid 15 is a sufficiently long time with respect to the maximum time T during which the plunger 18 moves from the combustion stop command and the pump internal pressure rises and then decreases. Therefore, the liquid fuel is not pushed out of the nozzle to the combustion section by the movement of the plunger 18.
Therefore, when the combustion is stopped, the liquid fuel at the nozzle tip can be reliably returned to the tank side, and defects such as generation of unburned gas, severe odor and tar generation caused by a rise in the temperature of the nozzle can be reduced. .

[0018]

As is apparent from the above description of the embodiment, the liquid fuel supply apparatus of the present invention can reliably prevent the liquid fuel from being pushed out by the movement of the plunger at the time of fire extinguishing. Tar formation and the like can be prevented beforehand. Therefore, the effect of reducing the odor and the production of tar obtained by returning the fuel from the nozzle tip at the time of fire extinguishing can be ensured, and good combustion can be performed over a long period of time.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a liquid fuel supply device according to an embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a hot air heater using the same device.

FIG. 3 is a block diagram showing a control unit of the apparatus.

FIG. 4 is a flowchart showing the operation of the control unit.

FIG. 5 is a characteristic diagram showing an operation of the control unit.

FIG. 6 is a sectional view of a main part of a warm air heater using a conventional fuel supply device.

FIG. 7 is a sectional view of a combustion unit according to the related art and the present invention.

FIG. 8 is a sectional view of a conventional electromagnetic pump.

[Explanation of symbols]

 2 Tank 4 Electromagnetic pump 5 Oil feed pipe 6 Combustion unit 10 Column 13 Discharge valve 15 Discharge solenoid 18 Plunger 16 Suction valve 24 Plunger solenoid 27 Suction pipe 30 Pump drive control unit 30a Discharge solenoid drive control unit 31 Combustion control unit

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Takehiko Shigeoka 1006 Kazuma Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (56) References JP-A-4-327712 (JP, A) JP-A-1- 252821 (JP, A) JP-A-63-54516 (JP, A) JP-A-59-42444 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F23N 1/00 105 F23K 5/04

Claims (1)

(57) [Claims] A tank for holding a liquid fuel, a plunger for sucking the fuel from the tank and supplying the fuel to a combustion section;
A solenoid for driving the plunger, a discharge valve provided downstream of the plunger, an electromagnetic pump having a discharge solenoid for driving the discharge valve to open, and a pump for controlling energization of the solenoid to drive the plunger A drive control unit, and a discharge solenoid drive control unit that opens a discharge valve by energizing the discharge solenoid, wherein the discharge solenoid drive control unit turns on the discharge solenoid after a predetermined time after the pump drive control unit stops energizing the solenoid. A liquid fuel supply device that energizes and opens a discharge valve.